CHURCHILL LIVINGSTONE An imprint of Elsevier Limited © Pearson Professional Limited 1995 © 2002, Elsevier Limited. All rights reserved. The rights of Linda M. Merriman and Warren Turner to be identified as editors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior permission of the publishers or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency, 90 Tottenham Court Road, London WIT 4LP. Permissions may be sought directly from Elsevier's Health Sciences Rights Department in Philadelphia, USA: phone: (+1) 215 238 7869, fax: (+1) 215 238 2239, email:
[email protected]. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com).by selecting 'Customer Support' and then 'Obtaining Permissions'. First edition 1995 Second edition 2002 Reprinted 2005 ISBN 0 443 07112 8 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress Note Medical knowledge is constantly changing. As new information becomes available, changes in treatment, procedures, equipment and the use of drugs become necessary. The authors and the publishers have taken care to ensure that the information given in this text is accurate and up to date. However, readers are strongly advised to confirm that the information, especially with regard to drug usage, complies with the latest legislation and standards of practice.
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Contributors
Robert L Ashford
C Payne DipPod (NZ) MPH
BA BEd MA MMedSci PhD DPodM MChS
Lecturer, Department of Podiatry, School of Human Biosciences, La Trobe University, Melbourne, Australia
Professor of Podiatry, Health and Social Care Research Centre, Faculty of Health and Community Care, University of Central England, UK Paul Beeson BSc(Hons) MSc DPodM Senior Lecturer, Northampton School of Podiatry, University College Northampton, UK Ivan Bristow MSc(Oxon) BSc(Hons) DPodM MChS Senior Lecturer, Faculty of Applied Sciences, University College Northampton, UK
A Percivall Senior Lecturer, School of Podiatry, University College Northampton, UK I Reilly DPodM BSc SRCh FCPod(S) Cert MHS DMS Senior Lecturer I Podiatric Surgeon, School of Podiatry, University College Northampton, UK
C J Griffith BSc(Hons) DPodM SRCh Private Practitioner, The Manse Health Centre, UK
Ian F Turbutt BSc(Hons) FChS FPodA FCPods Specialist in Podiatric Surgery, The Manor Hospital, Bedford; Ext. Lecturer in Podiatric Radiology, University of Brighton and University of Southampton, UK
Mary Hanley BSc(Hons) Psychology MSc PhD Senior Lecturer (Health Psychology & Research Methods), University College Northampton, UK
R Turner MB ChB MRCP Consultant Dermatologist, Churchill Hospital, Oxford, UK
Linda Merriman PhD MPhil DPodM MChS CertEd Dean, School of Health and Social Sciences, Coventry University, UK
Warren Turner BSc(Hons) DPodM Associate Dean, School of Podiatry, University College Northampton, UK
JMcLeod Roberts BSc(Hons) MSc DPodM Senior Lecturer, Northampton School of Podiatry, University College Northampton, UK Patricia Nesbitt DPodM MChS PGD(BioEng) Senior Lecturer, Faculty of Applied Sciences, University College Northampton, UK
Ben Yates MSc (Sports Injuries) BSc(Hons) FCPod Head, Podiatry Department, La Trobe University, Melbourne, Australia
Preface
Many textbooks make reference to the assessment of the lower limb but very few are dedicated entirely to this purpose. Those that are tend to focus on only one of the components of the process, e.g. skin disorders or on a specific client group such as paediatrics. The purpose of this book is to produce a textbook which encompasses all aspects of lower limb assessment. Problems affecting the lower limb can lead to discomfort, pain, reduction or loss of mobility and loss of time from work. Effective and efficient management of these problems can only be based on a thorough assessment. Throughout the book the term 'practitioner' is used in its broadest sense to denote any person who has an interest in the management of lower limb problems. Although the podiatrist has a natural claim to specialising in caring for the foot, the range of practitioners with an interest in the lower limb includes bioengineers, diabetologists, general medical practitioners, nurses, occupational therapists, orthopaedic surgeons, orthotists, physiotherapists and rheumatologists. This is the second edition of this textbook and, like the first edition, it is divided into four parts: Approaching the Patient, Systems Examination, Laboratory and Hospital Investigations and Specific Client Groups. Approaching the Patient provides an introduction to the assessment process and covers in detail the assessment interview, the presenting problem and the reliability and validity of clinical measurement. For the second edition these chapters have been reviewed and updated.
Systems Examination covers the separate components of lower limb assessment: medical and social history, vascular, neurological, orthopaedics, skin and appendages and footwear assessments. Details relating to anatomy and physiology have been discussed where relevant. Again, the chapters in this section have been updated as part of the second edition. The chapter on the assessment of skin and its appendages has been rewritten, as has the chapter on the locomotor system, which has been renamed orthopaedic assessment to reflect more accurately the content of the chapter. Laboratory and Hospital Investigations focuses on those tests which may be performed to confirm, support or clarify the clinical examination: blood analysis, urine analysis, microbial identification, histopathology, radiographic imaging and methods of quantifying gait and foot-ground interface systems. These chapters have been updated for the second edition. Reliance on tests without the appropriate clinical examination is unwise, creates higher costs, may worry the patient unnecessarily and overworks support departments. It is intended that this part of the book demonstrates when and how these tests can be used to aid the assessment process. The last part of the book, Specific Client Groups, looks at the main areas of foot disease: the at-risk foot, the child's foot, sport injuries and the painful foot. For the second edition two new chapters have been added to this section: assessment of the elderly and pre- and postoperative assessment. The addition of these chapters reflects the developments within podiatry. The elderly
x
PREFACE
form by far the largest client group receiving foot treatment; it is, therefore, important that the specific needs of this client group are addressed in this textbook. Over the last 10 years there has been a growth in the number of surgical procedures performed, under local analgesia, by podiatrists. Assessing a patient for surgery under local analgesia requires the practitioner to be aware of the specific issues related to this type of treatment as they do differ from those resulting from surgery under general anaesthesia. Although Systems Examination covers the range of assessments and can be applied to all age groups, the assessment of children and sports people is worthy of independent discussion. Pain in the foot can arise due to a multitude of factors, affects all age groups and has a highly morbid affect on our lives; for this reason, it has been given a separate chapter. The early diagnosis of the at-risk foot is recognised as a means of reducing morbidity, mortality and minimising the cost of in-hospital care for these patients.
Case histories and comments support some of the chapters, particularly those in Systems Examination and Specific Client Groups. These have been used to illustrate certain points and reflect real life experiences. Where appropriate, black and white photographs, figures and tables have also been used to support and further illustrate points raised in the text. A section of colour plates has been specifically used to support Chapters 6, 9 and 17. Each chapter has been referenced and some indicate Further Reading. Clearly there is more than one approach to undertaking an assessment. Assessment of the Lower Limb has been written to support good practice in a wide range of outlets for all professionals with an interest in the foot. Whatever approach the practitioner adopts, it is hoped that this text will be a valuable asset.
Linda Merriman, Warren Turner, 2002
Acknowledgements
We are indebted to those who have given their help and encouragement throughout the development and production of this second edition: in particular, our family and friends. A big thank you to all the contributors for their time and effort in updating and/or rewriting their chapters. We would also like to thank Ann Marie Carr for her help with the new chapter on assessment of the elderly.
This book is dedicated to Jackie McLeod Roberts in recognition of her contribution to podiatry and in particular her work in the Ukraine, developing and improving footcare services for people with diabetes. Jackie's pioneering work has made a significant difference to these people.
Plate 1 An ischaemic foot. The superficial tissues are atrophied. The fifth ray has been excised.
Plate 2 Typical ischaemic ulceration overlying a hallux abductovalgus in a patient with chronic peripheral vascular disease.
Plate 4 Telangiectasias: distortion of the superficial venules secondary to varicosity.
Plate 3 'Dry' gangrene, involving two toes. The necrotic area is surrounded by a narrow band of inflammation. The toes have become mummified, due to loss of the local blood supply.
Plate 5 Atrophie blanche (white patches), which occurs in association with chronic venous hypertension and venous ulcers.
Plate 7 Healed venous ulcer that had been present for 2 years.
Plate 6 Gravitational (varicose, stasis) eczema and haemosiderosis.
Plate 8 Venous ulceration in association with gross oedema and haemosiderosis (from Wilkinson J, Shaw S, Fenton 0 1993 Colour guide to dermatology. Churchill Livingstone, Edinburgh, Figure 179).
Plate 9 Histology section of normal hairy skin stained with haematoxylin and eosin. Light microscopy x 60.
Plate 11 Plate 10
Subungual exostosis affecting the second toe.
Koebner phenomenon in psoriasis due to injury.
Plate 13 Dorsal corn.
Plate 12 Extravasation within callus due to prolonged high pressure .
.. Plate 14
Plantar keratoderma.
Plate 15
Bullous pemphigoid.
Plate 17
Lichen planus.
Plate 18
Necrobiosis Iipoidica.
Plate 16
Plantar pustular psoriasis.
Plate 19
Acute contact dermatitis to adhesives in footwear.
CHAPTER TITLE
Plate 20 patient.
Plate 21 area.
Pseudomonas infection affecting the interdigital
Plate 23
Tinea pedis affecting the dorsum of the foot.
Extensive plantar warts in an immunosuppressed
Plate 22
Pitted keratolysis of the heel.
Plate 24
Interdigital melanoma.
5
6
PART TITLE
Plate 25
Pyogenic granuloma under the nail.
Plate 27 The sample of urine on the left is normal; the sample on the right is cloudy and tinged with blood, indicating infection.
PRINT DATE:
Plate 26 Metastatic lesion (secondary from a lung tumour).
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7
Plate 29 Dry fissures develop when the skin is too brittle to conform to external and internal mechanical stresses (tension and shear particularly). They are a frequent complication of anhidrosis and atrophy.
Plate 31
Plate 30 Hyperhidrosis, particularly interdigitally, leads to over-moist skin (macerated) which tears easily when mechanically stressed, sometimes exposing the dermis as seen here. Complications of hyperhidrosis include dermatophyte, yeast and bacterial infections.
Plate 32 Deep neuropathic ulcer which penetrates to the plantar tendons; there is no cellulitis or abscess formation. The patient was a noninsulin-dependent diabetic.
A typical neuropathic foot.
Plate 33 Bilateral arthropathy of the midtarsal joint, with ulceration of normally non-weightbearing soft tissues, in an insulin-dependent diabetic with peripheral neuropathy.
Plate 34
Plate 35 Typical neuroischaemic ulceration over the lateral aspect of the midfoot in a noninsulin-dependent diabetic, showing deep erosion of soft tissues, sloughy base, heavy peripheral callosity and maceration of superficial tissues.
A neuropathic ulcer on the plantar surface of the foot.
CHAPTER CONTENTS
Introduction 3 Why undertake a primary patient assessment? 3 The assessment process 4 Risk assessment 4 Making a diagnosis 5 Aetiology 7 Time management Re-assessment
L. Merriman
7
7
Recording assessment information Confidentiality
Assessment
8
9
Summary 10
INTRODUCTION Patients present with a range of signs and symptoms for which they are seeking relief and if possible a cure. However, before this can be achieved, it is essential to undertake a primary patient assessment. Ineffective and inappropriate treatment may result if the practitioner has not taken into account information obtained from the assessment. This chapter explores why it is necessary to undertake an assessment and considers specific aspects of the assessment process.
Why undertake a primary patient assessment? Information from the assessment helps the practitioner to: • arrive at a differential diagnosis or definitive diagnosis • identify the likely cause of the problem (aetiology), e.g. trauma, pathogenic microorganism • identify any factors which may influence the choice of treatment, e.g. poor blood supply, current drug regimen • assess the extent of pathological changes so that a prognosis can be made • establish a baseline in order to identify whether the condition is deteriorating or improving • assess whether a second opinion is necessary. 3
4
APPROACHING THE PATIENT
All the above information is essential if the practitioner is to provide effective treatment and care for the patient.
THE ASSESSMENT PROCESS Assessment comprises three elements; the interview, observation and tests (Table 1.1). Information from the interview and observation is used to formulate ideas as to the likely diagnosis and cause. Further information may be sought via the ihterview and the use of clinical and laboratory tests. The practitioner uses the data gained from the assessment to formulate a hypothesis(es) from which a diagnosis will be reached. This diagnosis will be used to inform the management plan (Fig. 1.1). Where possible, the cause (aetiology) of the problem should be identified, as part of the management plan would be to eradicate or reduce the effects of the cause. What has been outlined above is the ideal. In reality, patients often present with ill-defined problems and it is not possible to reach a definitive diagnosis. In these instances the practitioner explores a range of likely possibilities and develops the management plan in relation to these Table 1.1
Components of an assessment
Component Assessment interview
Presenting problem Personal details Medical history Family history Social history Current health status
Observation and clinical examination
Vascular Neurological Locomotor Skin and nails Footwear
Laboratory and hospital tests
Urinalysis Microbiology Blood tests History Gait analysis X-ray Other imaging techniques ECG Nerve conduction
Figure 1.1
The stages of assessment summarised.
possibilities. This approach focuses on symptom reduction and palliation. A good assessment requires that the practitioner demonstrates good interviewing (communication) and observational skills. It is essential that the practitioner has effective listening skills and knows when and which questions to ask the patient (see Ch. 2). Research has shown that most diagnoses are based on observation and information volunteered by the patient (Sandler 1979). Clinical, laboratory and hospital based tests provide additional data. Clinical tests involve physical examination of the patient (e.g. assessing ranges of motion at joints, taking a pulse) as well as near-patient tests such as assessing blood glucose levels with a glucometer. Most clinical tests are relatively quick and inexpensive to carry out and in most instances give fairly reliable and valid results. Technological advances mean that there are an increasing number of available clinical tests. Tests in laboratories and hospitals are more expensive and can be time-consuming. Such tests should only be used when it is necessary to confirm a suspected diagnosis, in cases of differential diagnosis or when the outcome of the test will have a positive influence on treatment.
Risk assessment Risk assessment can serve two purposes:
ASSESSMENT
• identify patients who need immediate attention • serve as a predictor for those 'at risk'. On account of the demands on time it is often necessary for the practitioner to differentiate between those patients who need immediate attention and those who do not. Table 1.2 summarises the presenting problems which should be given high priority. In clinics where there are lengthy waiting lists patients may be screened initially to assess whether they have one or more problems which appear in Table 1.2 and are then given immediate treatment. The term 'at risk' usually denotes those patients at risk of developing ulceration and infection. Identifying those at risk is a complex task. Currently, research into risk factors related to lower limb problems is sparse and thus it is difficult to produce risk assessment methods that are robust and valid. Considerable research has been undertaken into the risk assessment of pressure ulcers (Lothian 1987). In relation to the lower limb some work has been undertaken into developing methods of risk assessment to identify diabetics at risk of developing diabetic ulcers (Zahra 1998). Further work is needed in this Table 1.2 priority
Presenting problems which should be given high
Problem
Features
Pain
Constant, weightbearing and non-weightbearing Affects patient's normal daily activities
Infection
Raised temperature (pyrexia) Sign of acute inflammation Signs of spreading cellulitis Lymphangitis, lymphadenitis
Ulceration
Loss of skin Mayor may not be painful May expose underlying tissues
Acute swelling
Unrelieved pain Very noticeable swelling May have associated signs of inflammation
Abnormal skin changes
Distinct colour change Discharge may be malodorous Itching Bleeding
5
whole area before such measures can be used with confidence.
Making a diagnosis Arriving at a diagnosis is a complex activity. Studies of clinical reasoning show that practitioners use one or more of the following approaches (Higgs & Jones 2000): • hypothetico-deductive reasoning • pattern recognition • interpretative model. Hypothetico-deductive reasoning is based on generating hypotheses using clinical data and knowledge. These hypotheses are tested through further inquiry during the assessment. The evidence gained is evaluated in relation to existing knowledge and a conclusion reached on the basis of probability (Gale 1982). Pattern recognition is a process of recognising the similarity between a set of signs and symptoms. The important aspect of the use of categorisation in clinical reasoning is the link practitioners make between the pattern they are currently observing and previous cases showing the same or similar patterns. The interpretative model is very different from the other two models. This approach is based on the practitioner gaining a deep understanding of the patient's perspective and the influence of contextual factors. Protagonists of this approach believe that the meaning patients give to their problems, including their understanding of and their feelings about their problem, can significantly influence their levels of pain tolerance, disability and the eventual outcome (Ferurestein & Beattie 1995). Studies have shown that with all these approaches there is an association between clinical reasoning and knowledge (Higgs & Jones 2000). There is a symbiotic relationship between the knowledge base of practitioners and their clinical reasoning ability. It is not possible to develop problem-solving skills in the absence of cognitive knowledge related to the specific problem. There are three partners in the assessment process; the practitioner, the patient and the
6
APPROACHING THE PATIENT
wider environment. The ability of a practitioner to undertake an effective assessment and make a diagnosis is influenced by a range of factors: • • • • •
personal values, beliefs and perceptions knowledge base related to the problem(s) reasoning skills (cognition and metacognition) previous clinical experience familiarity with similar cases.
There can be enormous differences between practitioners, both in their assessment findings and their diagnoses. For example, Comroe & Botelho (1947) described a study in which 22 doctors were asked to examine 20 patients and note whether cyanosis was present. Under controlled conditions these patient were assessed for cyanosis by oximeter. When the results of the clinical assessment were compared with the oximeter results, it was found that only 53% of the doctors diagnosed cyanosis in subjects with extremely low oxygen content: 26% said cyanosis was present in subjects with normal oxygen content. Curran & Jagger (1997) found poor agreement between podiatrists when diagnosing common conditions of the leg and foot. Agreement improved when a patient expert system was used. Expert patient systems are increasingly being used, in particular in medicine (Adams et al 1986). These computer-based systems provide practitioners with a wealth of information and are used to guide and direct clinical decision making. Unfortunately, making a diagnosis is not a precise science: errors can and do occur. Practitioners should always keep an open mind when making a diagnosis, reflect on the process they have used, keep up to date with current literature and technology and request a second opinion when unsure. Sometimes the practitioner may have generated more than one possible diagnosis; in these instances the practitioner has to undertake a differential diagnosis, i.e. decide which is the most likely from a number of possibilities. When arriving at a differential diagnosis the practitioner should take into account the factors listed in Table 1.3. For example, a number of conditions affect specific age groups (e.g, the osteo chon-
Table 1.3 Factors which should be taken into consideration when making a differential diagnosis
Social history
Age Gender Race Social habits Occupation Leisure pursuits
Medical history
Family history Medication
Symptoms
Onset Type of pain Aggravated by/relieved by Seasonal variation
Signs
Site Appearance Symmetry
Specific tests
Imaging techniques Urinalysis Microbiology Blood analysis Biopsy Foot pressure analysis Electrical conductive studies
droses), whereas other conditions have specific presenting features (e.g. the sudden, acute, nocturnal pain associated with gout). The patient is the key partner in the assessment process. Some patients want to playa greater role in decision making and their health care management. Additionally, patients are increasingly being seen as consumers of health care. As such, they have expectations of the type and quality of the health services they receive. Patients' perceptions, beliefs and expectations related to their lower limb problems can be influenced by the following factors: • • • • • •
home environment work environment culture socioeconomic status language skills general state of health.
The above factors can affect patients' needs, communication skills and, ultimately, the choices they make. The wider health environment and context cannot be ignored in the assessment process.
ASSESSMENT
7
Health care is a political issue and government policy changes can radically affect available services. Finance is another major influencing factor that may limit the range of clinical and laboratory tests that may be used. Conversely, technological advances have led to improved clinical and laboratory test equipment. Employing organisations can affect the assessment process in a variety of ways, e.g. use of specific frameworks of operation. Profession-specific frameworks and the status of knowledge within the profession can also be influencing factors.
can assist in identifying the most appropriate treatment and help to produce an accurate prognosis. For example, if the cause of pain in the foot is chronic ischaemia due to atherosclerosis, the prognosis may be poor unless radical (bypass) surgery is performed. Conversely if the foot pain is due to acute ischaemia that has occurred as a result of hosiery constricting the peripheral circulation, the prognosis is good and advice may be all that is required. Unfortunately, it is not always possible to isolate the cause; in these cases the term idiopathic (unknown cause) is used.
Aetiology
TIME MANAGEMENT
Information from the assessment can enable the practitioner to identify the cause of the problem. A variety of aetiological factors can result in disorders of the lower limb. These can be divided into hereditary, congenital (present at birth) or acquired. Hereditary conditions may manifest immediately after birth, e.g. epidermolysis bullosa, or may not appear until some years after, e.g. Huntington's chorea. Congenital conditions include chromosomal abnormalities, e.g. Down's syndrome, developmental defects, e.g. spina bifida, or birth injuries such as cerebral palsy. Acquired conditions are those which arise after birth. Infection by a pathogenic organism resulting in sepsis is a common example of an acquired condition affecting the lower limb. Many conditions occur as a result of more than one factor, i.e. they are multifactorial. Atherosclerosis is thought to be due to the interplay of a number of factors, including dietary intake, familial high cholesterol level, high blood pressure, sedentary lifestyle and stress. In many cases predisposing factors present in conjunction with an exciting factor before the condition manifests. An example is a septic toe, where there has to be a portal of entry in order for the bacteria to gain entry into the skin and multiply. If the cause can be identified (e.g. lack of shock absorption, contamination by a pathogen) then treatment can be aimed at eradicating or reducing its effects. Knowing what has caused a problem
The assessment process is fundamental to a satisfactory outcome for both patient and practitioner. However, practitioners often find themselves working within strict time constraints and may feel they have" insufficient time in which to undertake a full primary patient assessment. It is important that the practitioner does not compromise the assessment process in order to save time. Such action, although it may deliver a short-term time saving, may result in unfortunate long-term effects. The practitioner who has not obtained important information or failed to recognise salient clinical findings may reach an incorrect diagnosis and/ or implement treatment, that puts the patient at considerable risk. In the long term this will lead to avoidable patient suffering and extra time being spent in dealing with the complications arising from treatment. In order to use time effectively it is important to plan and prioritise activities. The time allotted to a primary assessment may be as little as 5 minutes or may stretch to 30 minutes plus. On average practitioners should be able to undertake a routine assessment in 10 minutes; further time may be required if the problem is complex, if a definitive diagnosis cannot be reached or if laboratory or hospital tests are required. Table 1.4 identifies the essential components of any assessment.
RE-ASSESSMENT Assessment should not be something that is only undertaken on the patient's first visit. Every time
8
APPROACHING THE PATIENT
----------_._--------------------Table 1.4 The essential components of an assessment. These should be carried out with all patients. Further tests and examination should be used if indicated from the information obtained from the essential assessment
Observation
Gait as the patient walks into the room in order to detect abnormal function Facial features for signs of current health status
Interview
Presenting problem Personal details Medical history Family history Social history Current health status
Observation
Skin and nails to detect trophic changes and abnormal lesions Position of lower limb to note deformity, malalignment Footwear
Tests
Pulses, capillary filling time
the patient attends the clinic a mini-assessment should be undertaken in order that the following can be noted: • • • • •
changes to the patient's general health status changes to the status of the lower limb patient's perception of previous treatment effects of previous treatment information about treatment from other practitioners.
The process of assessment, diagnosis and treatment should be an uninterrupted loop: at every subsequent consultation, the patient should be re-assessed and evaluated (Fig. 1.2).
Figure 1.2
The assessment loop.
RECORDING ASSESSMENT INFORMATION Information gained from the assessment should be accurately and clearly noted in the patient's record. This record is the storehouse of knowledge concerning the patient and his/her medical history. It should contain a summary of the main points from the assessment and sufficient data to justify the diagnosis. Ideally, whether in a hospital or primary care setting, health care practitioners should use the same patient record. This ensures that all practitioners involved with the care of the patient are aware of each other's assessments and interventions. Although this is good practice, the keeping of separate records by each health care professional, e.g. general practitioner, district (home) nurses, podiatrists, is still prevalent. This practice does not facilitate teamworking. Two methods may be used to record the assessment information. The first involves using a blank piece of paper on which the practitioner writes, in a logical sequence, assessment and diagnostic details. The other involves the use of a pro-forma; this may vary from a form with a few headings to a very detailed format with boxes in which to write specific details. Such proformas can be self-designed or purchased from specialised suppliers. Whatever the method used, it is important that all details are written in such a way that practitioners not involved with the assessment can familiarise themselves with the salient details and any previous treatment. Records may be handwritten or typed; typed records are preferable as they are more legible but they do have resource implications. If handwritten, the handwriting must be legible and in ink (blue or black). The use of computers is already having an impact: it is likely that computers will eventually be the prime means of recording patient data. The record should be made at the time of the assessment: any blank spaces should be scored through. The original record should not be altered or disguised. If it proves necessary to amend the record, the nature of the amendment should be clear and the amendment should be
ASSESSMENT
signed and dated by the practitioner making the alteration. It is recommended that abbreviations should be avoided (Bradshaw & Braid 1999). The use of profession-specific abbreviations can be particularly problematic in multi-authored patient records, which are completed by more than one health care profession. However, the use of abbreviations in patient records is common. Curran (1994) noted that 97% of respondents used clinical abbreviations in their podiatric treatment records. All entries should be dated and signed. In particular, details regarding the patient's medication should always be dated, as the medication may have been changed by the time the patient attends for the next appointment. The patient's name or the patient identifier should appear on every page. Records should always be written in such a way as not to be offensive or contain subjective opinions. Most professional bodies provide guidance on recording information in patient records. For example, the Society of Chiropodists and Podiatrists (2000) produce Guidelines on the Minimum Standards in Clinical Practice, which contain specific information on record keeping. Bradshaw & Braid (1999) identified the following four reasons for poor record keeping: • • • •
illegible handwriting incomplete information inaccurate information ambiguous abbreviations.
It is suggested that practitioners as part of their continuing professional development receive periodic reminders and refresher sessions related to record keeping (Bradshaw & Braid 1999). It has been found that regular audit of medical records improves record keeping (Donnelly 1995). The information recorded from the assessment may be used for:
• ensuring contraindicated treatments are not used • clinical and epidemiological research • audit • planning • legal purposes.
9
Retrospective and prospective analysis of patient records is commonly used for clinical and epidemiological research, audit and planning. If well documented, they can provide a wealth of information. However, one of the problems with patient records is that there is no standardised manner in which information is collected. For example, the use of clinical terms can be ambiguous. The International Statistical Classification of Diseases, Injuries and Causes of Death was established by the World Health Organization as a universal system for collecting data. The system was originally designed for mortality statistics but has evolved to cover a broad range of diseases. It is updated every 10 years to keep abreast of the constantly changing information base. This system can be used to record diseases for the purpose of clinical and epidemiological research and audit. In an increasingly litigious society it is important that high standards of record keeping are maintained. The St Paul International Insurance Company Limited (1991) states that 35-40% of all malpractice claims in the United States cannot be defended because of 'documentation problems'. The Society of Chiropodists and Podiatrists (1998) found that inadequate patient records were the main reason why legal claims against state-registered chiropodists succeeded.
CONFIDENTIALITY The information volunteered by the patient and recorded in the patient's notes should be treated as confidential and not divulged to any other party without the consent of the patient. However, the information can be made available to all those involved with the care of that patient. Patient records, whether in manual or electronic format, are subject to the Data Protection Act 1998, which became effective from March 2000. This means that patients have the right of access, for a pre-set fee, to information stored about them. The act gives rights to individuals in
10
APPROACHING THE PATIENT
respect of personal data held about them by others. Where information about a patient is stored electronically it is a legal requirement that practitioners (or their employing organisation) comply with the notification requirements of the Data Protection Act (1998). If information is solely stored manually then there is no requirement to notify.
SUMMARY This chapter has stated the purpose of assessment and outlined the assessment process. If undertaken well, it leads to the drawing up of appropriate and effective treatment plans. It is therefore an activity that should be seen as pivotal to good patient-practitioner interaction.
REFERENCES Adams I D, Chan M, Clifford P 1986 Computer aided diagnosis of abdominal pain: a multi centre study. British Medical Journal 293: 80-84 Bradshaw T, Braid S 1999 The practice of recording clinical treatment and audit of practice - an overview for podiatrists. British Journal of Podiatry 2(1): 8-12 Comroe J H, Botelho S 1947 The unreliability of cyanosis in the recognition of arterial anoxemia. American Journal of the Medical Sciences 214: 1-6 Curran M 1994 Use of abbreviations in chiropody /podiatry. Journal of British Podiatric Medicine 49(5): 71-72 Curran M, Jagger C 1997 Interobserver variability in the diagnosis of foot and leg disorders using a computer expert system. The Foot 7: 7-10 Data Protection Act 1998 EC Data Protection Directive (95/46/EC) Donnelly A 1995 Improve your nurses' record collection. Nursing Management 2(3): 18-19 Ferurestein M, Beattie P 1995 Biobehavioural factors affecting pain and disability in low back pain: mechanisms and assessment. Physical Therapy 75: 267-280
Gale J 1982 Some cognitive components of the diagnostic thinking process. British Journal of Educational Psychology 52: 64-72 Higgs J, Jones M 2000 Clinical reasoning in the health professions, 2nd edn. Butterworth-Heinemann, London Lothian P 1987 The practical assessment of pressure sore risk. CARE Science and Practice 5(4): 3-7 Sandler G 1979 Costs of unnecessary tests. British Medical Journal 1: 1686-1688 Society of Chiropodists and Podiatrists 1998 Defensive practice (editorial). Podiatry Now 1(1): 1 Society of Chiropodists and Podiatrists 2000 Guidelines on minimum standards of clinical practice, December St Paul International Insurance Company Limited 1991 Defensible documentation. St Paul House, 61-63 London Rd, Redhill, Surrey RHI INA (information leaflet for health care professionals) Zahra J 1998 Can podiatrists predict diabetic foot ulcers using a risk assessment card? British Journal of Podiatry 1(3): 79-88
CHAPTER CONTENTS
Introduction 11 Is an interview different from a normal conversation? 11 Aims of the assessment interview 12
The assessment interview
Communicating effectively 12 Questioning skills 13 Listening skills 15 Non-verbal communication skills 16 Stereotyping 21 Documenting the assessment interview 21
M. Hanley
Structuring the asseSSment interview 22 Preparation 22 The interview 23 ,Closure 24 Confidentiality 25 What makes a good assessment interview? Summary
26
25
INTRODUCTION Research has shown that the interview, as opposed to any other method of assessment such as clinical tests and examinations, is the most efficient method in reaching an initial diagnosis (Sandler 1979). This chapter examines the purpose of the interview, the skills required to communicate effectively, how the interview should be structured and the pitfalls to avoid. It concludes by examining the features of a good assessment interview.
Is an interview different from a normal conversation? An interview is based upon a conversation between two or more people. As individuals we converse with a broad range of people. Conversation serves a multitude of purposes. The conversation in an interview differs from an ordinary conversation in a number of ways:
• It is an opportunity for an exchange of information. • It has a specific purpose; e.g. to solve a problem. • It has an outcome, e.g. a course of treatment. • It has less flexibility than an ordinary conversation. • The interviewer has a perceived position of authority/power over the interviewee. • It is important that this power is not abused. Every effort should be made to put the interviewee (the patient) at ease. 11
12
APPROACHING THE PATIENT
• A written record of the interview is usually kept. Practitioners may be involved with other types of conversation with patients, which require additional skills such as counselling, teaching and advising. These are discussed in the accompanying text to this book: Clinical skills in treating
the foot.
Aims of the assessment interview The assessment interview is a conversation with a purpose, which takes place between the practitioner and the patient. Patients present with problems, which may have physical, psychological and social dimensions. Patients often have their own ideas and concerns about the problems they present with, and about the medical care that they mayor may not receive. Likewise, practitioners approach the interview with perceptions of their role. These will have been influenced by training, past experiences, attitudes and beliefs. The availability of resources and facilities will contribute to the practitioner's response to the patient. It is essential that the practitioner and the patient develop common ground during the interview and that both are aware of each other's perspectives. If this cannot be achieved the interview may be an unsatisfactory experience for both of them. The prime purpose of the interview is for the cause of the patient's concerns to be identified and appropriate action taken. This is best achieved by the patient and the practitioner working in partnership to reduce or resolve these concerns. It is essential that the practitioner provides ample opportunity for the patient to convey his concerns and worries. In other words, the interview should be patient-centred. Research has shown that this is not always the case. A few years after qualification most practitioners are confident that they are good at taking histories and explaining things to patients. Is this confidence justified? A detailed analysis of the recordings of over 2500 doctor/patient interviews showed that 77% of them were doctor-
centred, compared with 21% classed as patientcentred (Byrne & Long 1976). Information gathered collectively from the interview and examination should facilitate the identification of the patient's health problem and, where appropriate, a diagnosis can be made. However, as well as aiding the diagnostic process, the interview serves other important purposes: • The information gained may be of help when drawing up a treatment plan. For example, the interview can provide a picture of the patient's social circumstances, which may affect the manner of, or the actual advice given. • It provides an opportunity to gain the patient's trust and confidence in you as a practitioner. • It facilitates the development of a therapeutic relationship between the health care practitioner and the patient. However, not all health care students are aware of how to communicate effectively and, as a result, communication skills training is becoming a common part of the curriculum in health care courses (Hargie et a11998, Sleight 1995).
COMMUNICATING EFFECTIVELY Since the interview plays a particularly significant role in the assessment of the patient, it is important to ensure that the meeting is successful. In other words, good communication skills are essential if you are to achieve an effective assessment interview. What is meant by communication? In its simplest form it can be seen as the transmission of information from one person and the receiving of information by another. Unfortunately, the communication process is not that simple; if it were there would not be communication breakdowns or misunderstanding between people as to what has been said. Communication can be influenced by characteristics of the sender (e.g. ability to express ideas clearly, verbal skills, attitude toward the patient), the receiver (e.g. the extent to which the receiver is paying attention, ability to hear and under-
THE ASSESSMENT INTERVIEW
stand the conversation, prior beliefs and expectations) or characteristics of the social environment in which the interview is being conducted (e.g. disruption due to background noise). With so many opportunities for these forms of interference, it is not surprising that many attempts to communicate effectively fail. Consequently, health care professionals should develop their communication skills in order to make the best use of the interview. A common question asked is: 'Are good communicators born or is it a skill you can learn?'. The answer has to be, it's a bit of both. We can all think of people we consider to be good communicators; these people appear to have an inherent skill. For others, communication may not come so easily. It is particularly important for health practitioners to be aware of and develop effective communication skills because so much clinical information is gathered through the assessment interview. Research has shown that with assistance and motivation, good communication skills can be developed (Ryden et aI1991). A myriad of books are available on the subject of communication skills. However, just reading a book does not automatically mean you become a good communicator. Observing others, noting good and bad points, receiving feedback from others, role-play exercises, video- and audiotaping of interactions, practising in front of a mirror or with friends are all helpful ways in which skills can be developed. Being an effective communicator is a skill - and like any clinical skill it should be regularly practised and reviewed. Constructive criticism is an essential part of learning but not always an easy method to accept! While you may not be able to change the communication characteristics of the patient or the social environment, you can ensure that your contribution to the interview is as effective as possible. You can do this by sending clear and appropriate messages to the patient and by ensuring that you understand fully what the patient is trying to communicate to you. In order to achieve this, you need to pay careful attention to three key components of the communication process:
13
• questioning skills • listening skills • non-verbal communication skills. Each of these skills will be considered in turn.
Questioning skills The prime purpose of the assessment interview is to gain as much information as possible from the patient in order that a diagnosis and treatment plan can be arrived at. To achieve this objective the practitioner uses a range of questioning skills. There are three categories of question: • open • closed • leading. Open questions. Open questions invite the patient to give far more than one-word answers. The patient is in a much better position to construct the response he wishes to give. Examples of open questions are:
• What happened when you went into hospital? • What do you look for when buying a pair of shoes? • What do you think is causing the problem? This sort of question can elicit information from the patient that you had not expected. Open questions are often preferable to closed questions such as 'When you were in hospital did they test your blood sugar or give you an X-ray?'. The patient may legitimately answer 'no' to these direct questions and fail to tell you that they undertook a test you have not mentioned. Closed questions. Closed questions limit the responses a patient may give. They usually require a one word response. Closed questions may: • require a yes/no response, e.g. Do you suffer from rheumatoid arthritis? • require the patient to select, e.g. Is the pain worse in the morning or the afternoon? • require the patient to provide factual information, e.g. How long have you been a diabetic?
14
APPROACHING THE PATIENT
Closed questions serve useful purposes during the assessment interview. They provide a quick means of gaining and verifying information. Patients often find them easier to answer than the more open type of question. They can be used to focus the assessment interview in a particular direction. On the other hand, if used too much they limit what the patient can say. As a result the patient may not volunteer important information. Leading questions. Leading questions should be avoided where possible. In general, they give responses that the professional expects to receive. Examples of leading questions are: • You don't smoke, do you? • That doesn't hurt, does it? • You said you get the pain a lot; that must mean you get it every day? While you may get the answer you want or expect to hear, it does not necessarily mean it is true! In addition to a specific style of question, the practitioner may also use a range of interview techniques to elaborate further on the issues raised. These techniques are often referred to as probes. Probing questions are a very useful adjunct to both open and closed questions. In general they aim at finding out more from the patient. In particular, they are useful in gaining in-depth rather than superficial information. Examples include: • Could you describe the type of pain it is? • What makes you think it might be linked to your circulation? You might also use silence as a probe to encourage the patient to expand on a given answer, or say 'yes', 'uh-hm' or simply nod, techniques that are particularly useful when you feel the patients may have more to say and are thinking about expanding their answer. General pointers when questioning patients
The following points should be borne in mind when interviewing patients:
• Show empathy. Authier (1986) defined empathy as: '[being] attuned to the way another person is feeling and conveying that understanding in a language he/she understands' . • Use language that is simple, direct and understandable. Avoid medical and technical terms. The 'fog index' can be used to assess the complexity of a piece of communication (Table 2.1). It is primarily used in written communication but has also been used, although less frequently, to analyse the complexity of the spoken word. It involves a mathematical equation that produces a score. For example, tabloid newspapers have a fog index score between 3 and 6, whereas government policy documents can achieve a score of 20+. Applying the fog index to spoken communication or a foot health education leaflet will give an indication of the complexity of that particular communication. If it receives a high fog index score, the average patient may find it very difficult to understand. • Avoid presenting the patient with a long list of conditions. This is especially important during medical history taking. It is unlikely that a patient has experienced more than one or two of the problems on a list. Patients may fall into the habit of replying 'no' to all the items on the list and fail to respond in the affirmative to ones they do suffer from. Strategies that can be used to avoid this situation include a pre-assessment questionnaire (see Ch. 5) or breaking up the list of closed questions with some open questions.
Table 2.1
The fog index
Take a passage of about 100 words, ending in a full stop. Work out the average sentence length. This is achieved by dividing the number of sentences into 100. Then work out the number of words of three or more syllables. Ignore twosyllable words that have become three syllables with plural or endings like -ed or -ing, technical words and proper nouns. Add the average sentence length to the number of difficult words and multiply by 0.4. The result will give you the reading score (fog index)
THE ASSESSMENT INTERVIEW
• Don't ask the patient more than one question at a time. For example, if asking a closed-type question do not say, 'Could you tell me when you first noticed the condition, when the pain is worse and what makes it better?'. By the end of the question the patient will have forgotten the first part. • Attempt to get the patient to give you an honest answer using his or her own words. Avoid putting words into the patient's mouth. • Clarify inconsistencies in what the patient tells you. • Get the patient to explain what he means by using certain terms, e.g. 'nagging pain'. Your interpretation of this term may differ from the patient's. • Pauses are an integral part of any communication. They allow time for participants to take in and analyse what has been communicated and provide time for a response to be formulated. Allow the patient time to think how he wishes to answer your question. Avoid appearing as if you are undertaking an interrogation. • In the early stages of the interview it is often better to use the term 'concern' rather than 'problem'. Asking patients what concerns them may elicit a very different response from asking them what the problem is. Some patients may feel they do not have a problem as such but are worried about some symptom or sign they have noticed. Asking them what concerns them may get them to reveal this rather than a denial that they have any problems. • Asking personal and intimate questions can be very difficult. Do not start the interview with this type of question; wait until further into the interview when hopefully the patient is more at ease with you. Try to avoid showing any embarrassment when asking an intimate question as this may well make the patient feel uncomfortable. • It is important that the patient understands why you are asking certain questions. Remember that the assessment interview is a two-way process: besides gathering infor-
15
mation from the patient it can be used for giving information to him. • Some patients, on account of a range of circumstances such as deafness, speech deficit or language difference, may not be able to communicate with the practitioner. In these instances it is important that the practitioner involves someone known to the patient to communicate on his behalf, e.g. relative, friend or carer. • The patient may have difficulty listening and interpreting what you are saying through fear, anxiety, physical discomfort or mental confusion. Be aware of non-verbal and verbal messages that can give clues to the patient's emotional state.
Listening skills Listening is an active not a passive skill. Many people ask questions but do not listen to the response. A common example is the general introductory question: 'How are you?'. Most responses tend to be in the affirmative: 'Fine', 'OK'. Occasionally, someone responds by saying they have not been too well, only to get the response from the supposed listener: 'Great; pleased to hear everything is fine'. Similarly, do not limit your attention to that which you want to hear or expect to hear. Listen to all that is being said and watch the patient's non-verbal behaviour. The average rate of speech is 100-200 words a minute; however, we can assimilate the spoken word at around 400 words per minute. As a result the listener has 'extra time' to understand and interpret what is being said. If you have asked a question you should listen to all of the answer. Often when trying to understand the clinical nature of a patient's problem, there is a great temptation to listen to the first part of an answer and then to immediately use this information to try and make a diagnosis. This may mean that you are not paying careful attention to important clinical information, which the patient may give, at the end of their reply. Finally, it is important that you don't let your mind wander on to unrelated thoughts such as what you are going to do after the interview. Before you know
16
APPROACHING THE PATIENT
it you have missed a good chunk of what the patient has been telling you and have most probably missed important and relevant information. In order to be a good listener you need to set aside your own personal problems and worries and give your full attention to the other person. It is inevitable that, at times, one's attention does wander. This may be due to lack of concentration, tiredness or because the patient has been allowed to wander off the point. In the case of the former do not be afraid to say to the patient, 'Sorry, could I ask you to go over that again?'. In the latter case, politely interrupt the patient and use your questioning skills to bring the conversation back to the subject in hand. During the interview the techniques of paraphrasing, reflection and summarising can be used to aid listening and ensure you understand what the patient is trying to convey. Paraphrasing. This technique is used to clarify what a person has just said to you in order to get him to confirm its accuracy or to encourage him to enlarge. It involves re-stating, using your own and the patient's words, what the patient has said. Reflection. This technique is similar to prompting in that it is used to encourage the patient to continue talking about a particular issue that may involve feelings or concerns. It may be used when the patient appears to be reluctant to continue or is 'drying up'. It involves the practitioner repeating in the patient's own words what the patient has just said. Summarising. This technique is used to identify what you consider to be the main points of what the patient is trying to tell you. It can also be a useful means of controlling the interview when a patient continues to talk at length about an issue. To summarise, the practitioner draws together the salient points from the whole conversation. At the end of the summary the patient may agree with, add to or make corrections to what the practitioner has said. Summarising serves a useful purpose in checking the validity, clarity and understanding of old information; it does not aim to develop new information. The basic skills of a good listener are highlighted in Table 2.2.
Table 2.2
Skills ofa good listener
• Look at the patient when he/she startsto talk • Use body language such as nodding, leaning forward to demonstrate to the speaker thatyou are interested in what is being said • Do not keep looking at the time • Adopt a relaxed posture • Use paraphrasing, reflecting and summarising to show the patient that you are listening to and understanding what he/sheis/are saying
Non-verbal communication skills This involves all forms of communication apart from the purely spoken (verbal) message. It is through this medium that we create first impressions of people and, similarly, people make initial judgements about us. Once made, first impressions are often difficult to change, yet research has shown they are not always reliable. Therefore, it is particularly important that we consider non-verbal communication here since it affects not only how we are perceived when we communicate but also how we make judgements about the patient. Non-verbal behaviour includes behaviours such as posture, touch, personal space, physical appearance, facial expressions, gestures and paralanguage (i.e. the vocalisations associated with verbal messages, such as tone, pitch, volume, speed of speech). It is said that we primarily communicate non-verbally. Remember the old adage 'a picture says a thousand words'. Your body language and paralanguage will send an array of messages to your patient prior to you saying anything. Non-verbal communication serves many useful purposes. It can be used to: • replace, support or complement speech • regulate the flow of verbal communication • provide feedback to the person who is transmitting the message, e.g. looking interested • communicate attitudes and emotions (Argyle 1972, Hargie et aI1994). The average person only speaks for a total of 10-11 minutes daily, with the average spoken sen-
THE ASSESSMENT INTERVIEW 17
tence lasting only around 2.5 seconds (Birdwhistell 1970). Therefore, non-verbal communication is the main mode of conveying our emotional state in most types of human interactions. In fact, in a typical conversation only onethird of the social meaning will be conveyed verbally - a full two-thirds is communicated through non-verbal channels! (Birdwhistell1970). Due to the broad literature in this area the following section will focus on selected aspects of non-verbal behaviour and how they may influence the success of the assessment interview. For the interested reader, there is a wide range of books available which look at the topic of non-verbal communication, many specialising in the clinical interaction: see Davis (1994), Dickson et al (1997), Hargie (1997), or the winter 1995 edition of the Journal of Nonverbal Behavior for further information on this topic. Eye contact. Eye-to-eye contact is frequently the first stage of interpersonal communication. It is the way we attract the other person's attention. Direct eye-to-eye contact creates trust between two people; hence, the innate distrust felt of someone who avoids eye contact. However, we do not keep constant eye-to-eye contact throughout a conversation. The receiver looks at the speaker for approximately 25-50% of the time, whereas the speaker looks at the other person for approximately half as long. So in other words, people tend to look more at the other person when they are listening compared with when they are speaking. Too much eye contact is interpreted as staring and is seen as a hostile gesture. Too little is interpreted as a lack of interest, attention or trustworthiness. Interviewers cannot afford to look inattentive because the patient may interpret this as meaning that he has said enough and as a result may stop talking. Conversely, withdrawing eye contact may be used as a legitimate way of getting the patient to stop talking. Health care practitioners should be aware of the frequency and duration of eye contact they have with their patients. The use of eye contact is important for assessing a range of patient needs and providing feedback and support, and its use during the interview should be based on the pro-
fessional judgement of the practitioner (Davidhizar 1992). Certainly eye-to-eye contact is recommended at the beginning of the interview, to gain rapport and trust, and at the end of the interview by way of closing the interview. However, you should always be aware of potential cultural and gender differences in appropriate level of eye contact. For example, Hall (1984) has reported that on average women tend to make more eye-to-eye contact compared with men, so adjust your non-verbal behaviour accordingly. Facial expression. Facial expression is arguably the most important form of human communication next to speech itself (Hargie et al 1994). It is via our facial expression we communicate most about our emotional state, and the meaning of a wide range of facial expressions (e.g. happy or sad) are recognised universally (Ekman & Fresen 1975). Smiling, together with judicious eye-to-eye contact, signifies a receptive and friendly persona and inspires a feeling of confidence and friendliness. Facial expressions often carry even more weight in a social interaction than the spoken word. For example, if a practitioner is giving a very positive verbal message to the patient but, at the same time, the practitioner's facial expression communicates anxiety and doubt, then it is likely that the patient will pay more attention to the facial message. This is because verbal behaviour is much easier to control than non-verbal and, as a result, non-verbal communication is likely to be more honest! Therefore, it is important that practitioners are always aware of the message they are communicating using their facial expressions. Posture and gestures. The manner in which we hold ourselves and the way in which we move says a lot about us as individuals. This area of non-verbal behaviour is often referred to as kinesics and includes all those movements of the body which complement the spoken word (e.g. gestures, limb movements, head nods, etc.), One particularly important aspect is posture. Four types of posture have been identified:
• approaching posture, which conveys interest, curiosity and attention, e.g. sitting upright
18
APPROACHING THE PATIENT
and slightly forward in a chair facing towards the person you are communicating with • withdrawal posture, which conveys negation, refusal and disgust, e.g. distance between the receiver and the communicator, shuffling, gestures indicating agitation • expansion, which conveys a sense of pride, conceit, mastery, self-esteem, e.g. expanded chest, hands behind head with shoulders in air, erect head and trunk • contraction, which conveys depression, dejection, e.g. sitting in a chair with head drooped, arms and legs crossed or head held in hands, avoiding eye contact. Clearly, the posture adopted by the health care practitioner is important in developing a rapport and a working therapeutic relationship with the patient. When we speak we also tend to use our arms and hands to reinforce and complement the verbal message. In fact, when people are constrained from using their arms and hands, they experience greater difficulty in communicating (Riseborough 1981). Self-directed gestures such as ring twisting, self-stroking and nail biting may indicate anxiety. Be aware of self-participation in these types of activities as you may convey a non-verbal message of anxiety to your patient while verbally you are trying to convey a confident approach. The health care profession should be sensitive to the non-verbal gestures used by the patient as these may reveal more about the patient's thoughts and feelings than they are able to communicate verbally (Harrigan & Taing 1997). Touch. The extent to which touching is permissible or encouraged is related to culture (McDaniel & Andersen 1998). In general, the British people are not known as a nation of Table 2.3
'touchers'. During the assessment it may be necessary to touch the patient in order to examine a part of his body. This type of touching, known as functional touching, is generally acceptable to most patients as part of the role of the practitioner and as such does not carry any connotation of a social relationship. However, people from certain cultures may find it difficult to accept, even in medical settings. Prior to functional touching of a patient, it is important that you inform the patient what you intend to do and the reasons for doing it. During the interview you may wish to use touch as a means of reassuring the patient, to indicate warmth, show empathy or as a sign of care and concern (McCann & McKenna 1993). A hand lightly placed upon a shoulder or holding a patient's hand are means of showing concern and giving reassurance. It is difficult to produce guidelines for when this type of touching should or should not be used. Practitioners must feel confident and happy in its use, and must also take into account a multitude of communication cues from the patient before deciding whether it is or is not appropriate (Davidhizar & Newman 1997). Proxemics. All of us have a sense of our own personal territory. When someone invades that territory, depending upon the situation, we can be fearful, disturbed or pleased and happy. As with touch, our sense of personal space is affected by culture. In some cultures individuals have a large personal space, whereas in others they have a very small personal space. Encroaching on someone else's personal space can be perceived as intimidation and, in the case of the assessment interview, may put patients on their guard. As a result the patient may become reluctant to disclose relevant information. Hall (1969) defined the four zones of personal space (Table 2.3).
Four zones of personal space (Hall 1969)
Zone
Distance
Activities
Intimate Personal Social/consultative Public
0-0.5 metres 0.5-1 .2 metres 1 .2-3 metres 3 metres +
Intimate relationships/close friends What is usually termed 'personal space' Distance of day-to-day interactions Distance from significant public figures
THE ASSESSMENT INTERVIEW
19
The zone in which people interact is highly influenced by social status and people who have an equal status tend to interact at closer distances (Zahn 1991). The assessment interview usually takes place in the social/consultative and the personal zone. During the interview it may be necessary to enter the intimate zone. Prior to doing this, notify the patient in order to justify any actions requiring closer contact. Social interactions are not only influenced by distance, but also by bodily orientation. The angle
at which you conduct the assessment interview may have a significant effect on the success of the interaction. There are four main ways in which you can position yourself in order to interact with the patient (Fig. 2.1): (i) conversation; (ii) cooperation; (iii) competition; and (iv) coaction. Research indicates that the conversation position is most appropriate for an assessment interview. In fact, research has shown that when CPs sat at a 90Q angle to their patients during a clinical interview, the amount of
A
B
C
o
Figure 2.1 Body orientation may influence the success of the interview. The figures show four positions commonly encountered when two people interact. Which of the following orientations do you think would be most appropriate for the assessment interview? A. Conversation B. Cooperation C. Competition D. Coaction.
20
APPROACHING THE PATIENT
clinician-patient information exchanged increased by up to six times compared with when they interacted face-to-face (Pietroni 1976). Clearly, the health care professional needs to be aware of the physical position they adopt when assessing a patient as this will have a significant impact on the kind of relationship they are hoping to achieve (Worchel1986). Physical appearance. We use our clothing and accessories to make statements about ourselves to others. Clothing can be seen as an expression of conformity or self-expression, comfort, economy or status. Uniforms are used as intentional means of communicating a message to others; often the message is to do with status. Uniforms are also used in the health care professions for cover and protection. Whether one wears a uniform (white coat, coloured top and trousers) for the assessment interview is open for debate, but one should pay attention to issues of cleanliness and appearance of dress, hair, hands, footwear and accessories such as jewellery - they all send messages to the patient. In addition to physical factors, which can be altered, you should also be aware of how 'nonchangeable' physical characteristics may playa role in your interaction with the patient. For example, physically attractive and/or taller people are typically judged more favourably in general social interactions (Hensley & Cooper 1987, Melamed & Bozionelos 1992). Research has shown that within a health care environment, children make judgements about health care professionals on the basis of height. In general, taller health professionals were judged to be stronger and more dominant than their smaller colleagues, but they were not considered to be more intelligent nor more empathetic (Montepare 1995). Finally, health care practitioners should also be aware of the impact of their appearance on any health promotion message that they hope to communicate. For example, the patient will often pay attention to the footwear worn by the practitioner. Avoid giving conflicting verbal and nonverbal messages, e.g. by wearing high-heeled slip-on shoes while advising patients that they should not wear this type of shoe.
Paralanguage. This involves the manner in which we speak. It includes everything from the speed at which we speak to the dialect we use. Paralanguage is the bold, underlining, italics and punctuation marks in our everyday speech! An individual who speaks fast is often considered by the receiver to be intelligent and quick, whereas a slow drawl may be associated with a lower level of intelligence. When talking to patients we should be careful not to speak too quickly as they will not understand what we say. Conversely, if speech is too slow, the patient may not have confidence in the practitioner. When we speak we use pitch, intonation and volume to affect the message we transmit. Individuals who speak at a constant volume and do not use intonation and/or alter their pitch often come across as monotonous, dull and boring. Such speech is often difficult to listen to. Intonation and pitch should be used to highlight the important parts of your question and can be used to change the point you are trying to make. For example, in the following sentence you can see how changing the point of emphasis changes the message you are trying to get across.
• You must use the cream on your foot daily, i.e. treatment is the responsibility of the patient. • You must use the cream on your foot daily, i.e. it is essential that the treatment is carried out. • You must use the cream on your foot daily, i.e. it is important that the cream is usedand not
some othersubstance. • You must use the cream on your foot daily, i.e. the cream should be used on the foot and not
some other partof the body. • You must use the cream on your foot daily, i.e. treatment needs to beon a regular basis. The fluency with which we speak also tends to convey messages about mental and intellectual abilities. Repeated hesitations, repetitions, interjections of 'you know' or 'urn' and false starts do not inspire confidence in the receiver (Christenfeld 1995). We all experience occasions when we are not as fluent as at other times. These occasions tend to occur when we are tired or under great stress. If possible, these times should be keep to a minimum during clinical assessment.
THE ASSESSMENT INTERVIEW
Dialect conveys which part of the country we originate from. It may also cause us to use vocabularya person from another part of the country is not familiar with. Avoid using colloquial terms. Dialect, on the other hand, is not so easy to alter. The only time it should be considered is when patients cannot understand what the practitioner is saying. Finally, volume should not be changed too regularly. Shouting at the patient should be avoided. In the clinical setting, as in life in general, it certainly does not guarantee that the other person will listen more to what you say! From this section it should be clear that health care professionals need to be sensitive to the kind of atmosphere they are creating through their non-verbal communication, and the role this may have in the subsequent interaction with the patient. The extent to which you establish a satisfactory rapport will depend heavily on your nonverbal skills and how you develop them in your clinical work (Grahe & Bernieri 1999).
Stereotyping Health care practitioners should be aware of their own underlying psychological characteristics, which may have a profound effect on the interaction - i.e. stereotypes. A stereotype is a belief that all members of a particular social group share certain traits or characteristics (Baron & Byrne 2000). For example, you might hold particular ideas about the characteristics of a patient who is an alcoholic, elderly, from an upper social class group, from a minority ethnic group or female. In fact, you probably already hold a range of stereotypes about a wide group of patients whom you have never actually treated! While stereotypes are not always negative, they do share a common characteristic in that they reduce the ability of the health care worker to see the patient as an individual. Consequently, any information gathered from the patient during the assessment interview is likely to be interpreted in the light of such stereotypes (Price 1987). Ganong et al (1987) conducted a review of 38 research studies, which examined stereotyping by nurses and nursing students. Results indicated that nurses held stereotypes about patients on the basis of age,
21
gender, diagnosis, social class, personality and family structure. However, the impact on actual patient care was harder to classify. What does seem to be the case is that patients were less likely to be seen as having unique concerns, health problems and social circumstances. Consequently, in addition to practising interviewing skills, it is important for health care practitioners to reflect on any belief systems they may hold regarding particular patient groups, and consider how such views may impair the overall success of the assessment interview.
Documenting the assessment interview It is essential either during or at the end of the assessment to make a permanent record of the findings of the interview. This record is essential as an aide-memoire for future reference when monitoring and evaluating the treatment plan and as a means of communicating your findings to another practitioner who may collaborate in treating the patient. Despite recent discussions within the field of podiatry regarding changing to electronic data management systems, the majority of patient records are still stored on paper. However, the use of computerised records is on the increase, particularly in private practice. It may well be in the future that paper records are discarded completely, and replaced by computerised techniques. Whatever the future may hold, the need for clear, accurate recording of information will still be the same. The recording of assessment findings, together with the recording of treatment provided, forms a legal document. Patient records would certainly be used if action was taken by a patient against a practitioner, or if certain agencies required detailed evidence of management and progress in the case of disability awards. Patient records may take a variety of forms: at the simplest level a plain piece of paper may be used. If using plain paper it is essential to adopt an order to the presentation of your assessment findings: e.g. name, address, doctor, age, sex, weight, height, main complaint, medical history,
22
APPROACHING THE PATIENT
etc. This is considered further in Chapter 5. A variety of patient record cards exist in the NHS and private practice. Many practitioners and health authorities produce their own tailor-made record card. The Association of Chief Chiropody Officers produced a standard record in 1986 for charting foot conditions, diagnoses and treatment progress. Handwritten recording of information requires the following: • The writing is legible and in permanent ink, not pencil. If another practitioner cannot read your writing the information is of no use. • The information is set in a clear and logical order. It is essential to use an accepted method. • Accurate recording of location and size of lesions or deformities. The use of prepared outlines of the feet are very good for indicating anatomical sites and save additional writing. • Abbreviations are avoided where possible. What is obvious to you may not be so obvious to another practitioner. • Entries are dated. Recording the medication a patient is taking is useless unless it is dated. Once dated the information can be updated as and when there is a change. • Each entry should be signed and dated by the practitioner.
STRUCTURING THE ASSESSMENT INTERVIEW Preparation In order to achieve a good assessment interview it is essential you prepare yourself for the interview. The following should be taken into consideration. Purpose. It is essential that the practitioner is clear as to the purpose of interview. In some instances the assessment interview may be used as a screening mechanism to identify patients for further assessment. It may be used to gain information from patients in order that their needs can be prioritised and those judged to be urgent can be seen first. On the other hand, the assess-
ment interview may be aimed at undertaking a full assessment of the patient, with treatment provided at the end of the interview. Letter of application. Was the patient referred or self-referred? If the patient was referred by another health care practitioner there should be an accompanying letter of referral. Read this carefully so you are fully informed of the reasons for referral. This information should be used as a starting point for the assessment. If patients have referred themselves directly (self-referred) they should complete any appropriate documentation prior to the interview. Information on application forms can be used to prioritise patients and ensure the most suitable practitioner sees them. If no application form or letter of referral is available the practitioner has very little information prior to the interview, possibly only the patient's name. You may wish to give the patient a short health questionnaire to complete prior to the assessment (pp. 77-78). This questionnaire may be sent to the patient prior to the interview or the patient may be asked to fill it in on arrival. These questionnaires provide the practitioner with important information before the start of the interview. The patient should be allowed time to complete the questionnaire in order that he can think about his responses. The advantage of such a questionnaire is that the practitioner does not have to ask the patient a series of routine questions during the interview. However, some patients may be reluctant to fill in a form without having met the practitioner or reluctant to disclose information in writing. Prior to the interview try to read all the information you have about the patient. You can then come across to the patient as well informed and as someone who has taken an interest in him. Patient expectations. Does the patient know what to expect from the assessment interview? Some new patients, prior to attending their assessment appointment, are sent an information sheet or booklet explaining the purpose of the assessment interview and what will happen during it. Such an initiative is helpful. The cause of a poor interview may be that the patient's expectations of what will happen are very differ-
THE ASSESSMENT INTERVIEW
ent from what actually happens. For example, a patient who expected immediate treatment and had not envisaged any need for history taking may well say, 'Why are you asking me all these questions?'. Table 2.4 highlights what should be contained in a patient information booklet. Waiting room. Patients can spend a lot of time in the waiting room, especially if they arrive too early or are kept waiting due to unavoidable circumstances. Try sitting in the waiting room in your clinic. Look around you: how welcoming is it? The waiting room sets the scene for the rest of the interview. Where possible, ensure that it is in good decorative order, clean, with magazines to read and informative, eye-catching posters or pictures on the wall. Make the most of a captive audience to put over important health education information. TV monitors showing health promotion videos may be used. The name of the practitioner displayed outside the clinic may be useful. Some clinics, like a number of high street banks, have a display of photographs with the names and titles of those within the department or centre. Interview room. The assessment interview may be carried out in an office or in a clinic. Both have advantages and disadvantages. Using an office prevents the patient being put off by surrounding clinical equipment. It facilitates eye-to-eye contact by sitting in chairs, and provides a nonclinical environment. This is especially useful if Table 2.4
Information booklet for patients to read prior to the interview The booklet should contain the following information: The purpose of the assessment interview How long the interview should take What will happen during the interview Specific information the patient may be asked to provide, e.g. list of current medication Specific items the patient may be asked to bring, e.g. footwear • Examples of questions he/she is likely to be asked • The possible outcomes of the assessment interview, e.g. whether the patient will receive treatment at the end of it. The booklet may also contain a health questionnaire for the patient to complete and bring to the assessment interview.
23
treatment is not normally provided at the end of the assessment. On the other hand, using a clinic ensures that clinical equipment is readily to hand and the patient can be moved into different positions if there are controls on the couch. During the interview you should ensure that you are not disturbed. If there is a phone in the room, redirect calls. Ensure the receptionist does not interrupt. While the patient is in the room you should be giving him your undivided attention. Constant disturbances not only makes the assessment interview a protracted occasion but also can prompt the patient into feeling that his problem is not worthy of your attention.
The interview When the patient enters the room, welcome him to the clinic, preferably by name. This personalises the occasion for the patient and at the same time ensures that you have the correct patient. If you have difficulty with the patient's name, ask politely how to pronounce it rather than doing so incorrectly. Introduce yourself. As part of the Patient's Charter you should be wearing a name badge but a personal introduction is usually preferable, especially if the patient's eyesight is poor. It is useful to shake the patient by the hand since touch is an important aspect of non-verbal behaviour (as discussed earlier), although this may be influenced by personal preference. At this stage you may find it helpful to make one or two general conversation points about the weather, the time of year or some news item. This enables patients to see you as a fellow human. Remember that during the interview they are going to give a lot of themselves to you. It is important that patients feel you are someone they wish to disclose information to. Use the introduction as an opportunity to explain the purpose of the interview and what will happen. The positioning of patient and practitioner can influence the success of the assessment interview. Ideally, you and the patient should be at the same level in order to facilitate eye-to-eye contact. Barriers such as desks are often used in medical interviews. They can be considered as means of
24
APPROACHING THE PATIENT
making the interview formal. Standing over a patient who is sitting down or lying on a couch may be intimidating. Data gathering. It is essential that the practitioner is clear as to what areas should be covered in the interview. A logical and ordered approach should be adopted. However, it is not always possible or desirable to stick to an ordered approach. Patients tend to talk around issues or elect to give information about a question that you asked earlier at the end of the interview. You must make allowances for this. Effective and efficient use of time is paramount. Experienced practitioners combine the interview with the examination. This is achieved by, for example, feeling pulses and skin temperature while simultaneously asking questions about medical history. This technique is a matter of preference; some prefer to complete the interview before commencing the examination. After each assessment interview reflect upon it. Ask yourself how you could improve your performance and how you could make better use of the time. This will help you to make the best use of the data-gathering stage of the interview. Peer appraisal is another mechanism that you may find helpful in aiding you to develop good data-gathering skills.
Closure Bringing the assessment interview to a close is a difficult task. When do you know you have enough information? This is a difficult question to answer. Some presenting problems, together with information from the patient, can be easily diagnosed. Other problems are not so easy to resolve and may require further questioning and investigations. General medical practitioners have been shown to give their patients, on average, 6 minutes of their time. Psychotherapists, on the other hand, spend 1 hour or more on each assessment. Unfortunately the demands on practitioners' time means they are often not in a position to give the patient as much time as they would like.
As a general rule of thumb the interview should be brought to a close when the practitioner feels the patient has been given an opportunity to talk about the problem. Body language can be used to convey the closing of the interview. Standing up from a sitting position, shuffling of papers, withdrawing eye-to-eye contact are all ways by which the end of the interview can be conveyed to the patient, together with a verbal message. The patient should not leave the interview without fully understanding what is to happen next and without an opportunity to ask questions. A range of outcomes may result from the assessment interview (Table 2.5). Patients should know which outcome applies to them. They should always be given the opportunity to raise any queries or concerns they may have prior to leaving the assessment. This is one of the most important parts of the assessment and should not be hurried. The patient must leave the assessment fully understanding the findings of the assessment interview and what action, if any, is to be taken, and it is the responsibility of the health care professional to ensure that they have communicated such information clearly (Calkins et al 1997). It is helpful to provide written instructions as a follow-up to the interview. For example, if the patient is to be offered a course of treatment what will the treatment involve, when will it be given, who will give it, what problems may the patient experience? Table 2.5
Outcomes from the assessment interview
• Treatment is not required; the patient requires advice and reassurance • The patient can look after the problem once appropriate self-help advice has been given • A course of treatment is required; the patient should be informed as to whether treatment will commence straight after the assessment interview or at a later date • The patient needs to be referred to another practitioner for treatment • Further examination and investigations are required before a definitive diagnosis can be made • A second opinion is required • The urgency for treatment should be prioritised
THE ASSESSMENT INTERVIEW
Confidentiality The information the patient divulges during the interview is confidential. It should not be disclosed to other people unless the patient has given consent. The Data Protection Act 1998 requires that all personal data held on computers should be 'secure from loss or unauthorised disclosure'. The General Medical Council (1991) and the National Health Service (1990) have laid down guidelines on confidentiality.
WHAT MAKES A GOOD ASSESSMENT INTERVIEW? The prime purpose of the assessment interview is to draw out information, experiences and opinions from the patient. It is the duty of the interviewer to guide and keep the interview to the subject in hand. At the same time, it is equally important to encourage the patient to talk and to clear up any misunderstandings as you go along. Keeping the balance between these two competing aims is not an easy task. One way of checking on this is to ask yourself who is doing most of the talking. Is it you or the patient? If you are to achieve the aims of the assessment interview it should be the patient. It is not essential that you like the patient you are interviewing. What is important is that you adopt a professional approach, demonstrate empathy and deal with the patient in a competent and courteous manner. It is essential that you do not make value judgements based on your own biases and prejudices. Respect the patient; avoid stereotyping. Do not jump to conclusions before reaching the end of the interview. As highlighted earlier, the assessment interview should be patient-centred; its prime purpose is to gain information from the patient. However, one sometimes comes across patients who appear unable to stop talking. What can the practitioner do in these instances? The first question to ask is why the patient is talking so much. Is it because he is lonely and welcomes the opportunity to talk, is he very selfcentred, is he avoiding telling you what the real concern is by talking about minor issues? The
25
reason will influence the action you take. If you feel the patient wants to tell you something but is finding it difficult, try reflecting or summarise what you think has been said. Ask if there is anything else the patient would like to discuss. Encourage patients by telling them that you want to be able to help as much as you can; the more they tell you about their concerns the more you can help them. On the other hand, if you feel you need to control a talkative patient you may find the following techniques helpful: • use eye contact and your body language to inform the patient that you are bringing a particular section of the interview to a close • politely interrupt the patient, summarise what he has said and say what is to happen next • ask questions that bring the patient back to the topic under discussion. The converse of talkative patients are those who are reluctant to disclose information about themselves. This may be because they do not see the purpose of the questions you are asking, they are shy, they cannot articulate their concerns, they are fearful of what the outcomes may be or they are too embarrassed to disclose certain information. Your response will depend on the cause of the reticence. Explaining why you need to know certain information will be helpful if the patient is hesitant. For example, a patient may wonder why you need to know what medication he is taking when all he wants is to have a corn treated. If you feel the patient cannot articulate what he wants to say, you may find that closed questions can help. This type of questioning limits responses but can be helpful for a patient who has difficulty putting concerns and problems into words. You need to use a range of closed questions and avoid leading questions if you are to ensure you reach an accurate diagnosis. The shy or embarrassed person may find selfdisclosure very difficult. It has been shown that people tend to disclose more about themselves as they get older. In general, females disclose more than males. When privacy is ensured and the
26 APPROACHING THE PATIENT
interviewer shows empathy, friendliness and acceptance, patients have been shown to disclose more information. Reciprocal disclosure can also be helpful. Feedback. In order to develop your interview technique it is important that you obtain feedback on your performance. Mention has already been made of self- and peer assessment of the interview. This is a valuable process, which should be ongoing. Patient feedback is another valuable mechanism. Questionnaires (postal or self-administered) and structured or unstructured interviews are ways in which patient reactions to the interview can be obtained. Suggestions as to how to improve interviews should be welcomed.
SUMMARY The interview is the process of initiating an assessment of the lower limb. The relationship created between the practitioner and the patient during the interview will hopefully lead to an effective diagnosis. A good interview can provide the majority of the information required without having to resort to numerous tests and unnecessary examination. There is no one formula that can be applied to all assessment interviews. Each patient should be treated as an individual with specific needs. Practitioners should develop their interviewing skills in order that the interview achieves a successful outcome for the patient and the practitioner.
REFERENCES Argyle M 1972 The psychology of interpersonal behaviour. Penguin, Harmondsworth Authier J 1986 Showing warmth and empathy. In: Hargie (ed) A handbook of communication skills. Routledge, London Baron R A, Byrne D 2000 Social psychology, 9th edn. Allyn & Bacon, Boston Birdwhistell R L 1970 Kinesics and context. University of Pennsylvania Press, Philadelphia Byrne P, Long E 1976 Doctors talking to patients: A study of verbal behaviour of general practitioners consulting in their surgeries. HMSO, London Calkins D, Davis R, Reiley P et al1997 Patient-physician communication at hospital discharge and patients' understanding of the postdischarge treatment plan. Archives of Internal Medicine 157: 1026 Christenfeld N 1995 Does it hurt to say Urn. Journal of Nonverbal Behavior 19: 171 Data Protection Act 1998 EC Data Protection Directive (95/46 EC) Davidhizar R 1992 Interpersonal communication: a review of eye contact. Infection Control and Hospital Epidemiology 13: 222 Davidhizar R, Newman J 1997 When touch is not the best approach. Journal of Clinical Nursing 6: 203 Davis C 1994 Patient practitioner interaction: An experiential manual for developing the art of healthcare, 2nd edn. Slack Inc, New Jersey Dickson D, Hargie 0, Morrow N 1997 Communication skills training for health professionals, 2nd edn. Chapman & Hall, London Ekman P, Fresen W V 1975 Unmasking the face. PrenticeHall, Englewood Cliffs, New Jersey Ganong L H, Bzdek V, Manderino M A 1987 Stereotyping by nurses and nursing students: a critical review of research. Research in Nursing and Health 10: 49
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General Medical Council 1991 Professional conduct and discipline: Fitness to practice. GMC, London Grahe J, Bernieri F 1999 The importance of nonverbal cues in judging rapport. Journal of Nonverbal Behavior 23: 253 Hall E T 1969 The hidden dimension. Doubleday, New York Hall J A 1984 Nonverbal sex differences: communication accuracy and expressive style. Johns Hopkins University, Baltimore Hargie 1997 The handbook of communication skills, 2nd edn.Routledge,London Hargie 0, Saunders C, Dickson D 1994 Social skills in interpersonal communication, 3rd edn. Routledge, London Hargie 0, Dickson D, Boohan M, Hughes K 1998 A survey of communication skills training in UK schools of medicine: present practices and prospective proposals. Medical Education 32: 25 Harrigan J, Taing K 1997 Fooled by a smile: detecting anxiety in others. Journal of Nonverbal Behavior 21: 203 Hensley W, Cooper R 1987 Height and occupational success: a review and critique. Psychological Reports 60: 843 McCann K, McKenna H P 1993 An examination of touch between nurses and elderly patients in a continuing care setting in Northern Ireland. Journal of Advanced Nursing 18:38 McDaniel E, Andersen P 1998 International patterns of interpersonal tactile communication. Journal of Nonverbal Behavior 22: 59 Melamed J, Bozionelos N 1992 Managerial promotion and height. Psychological Reports 71: 587 Montepare J 1995 The impact of variations in height in young children's impressions of men and women. Journal of Nonverbal Behavior 19: 31 National Health Service Circular No 1990 (Gen) 22, 7 June 1990 A code of practice on the confidentiality of personal health information. London
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THE ASSESSMENT INTERVIEW 27
---------------------------Pietroni P 1976 Non-verbal communication in the GP surgery. In Tanner B (ed) Language and communication in general practice. Hodder & Stoughton, London Price B 1987 First impressions: paradigms for patient assessment. Journal of Advanced Nursing 12: 699 Riseborough M 1981 Physiographic gestures as decoding facilitators: three experiments exploring a neglected facet of communication. Journal of Nonverbal Behavior 5: 172 Ryden M B, McCarthy P R, Lewis M L, Sherman C 1991 A behavioural comparison of the helping styles of nursing students, psychotherapists, crisis interveners, and
untrained individuals. Archives of Psychiatric Nursing 5: 185 Sandler G 1979 Costs of unnecessary tests. British Medical Journal 1: 1686-1688 Sleight P 1995 Teaching communication skills: part of medical education. Journal of Human Hypertension 9: 67 Worchel S 1986 The influence of contextual variables on interpersonal spacing. Journal of Nonverbal Behavior 10:230 Zahn G L 1991 Face-to-face communication in an office setting: the effects of position, proximity and exposure. Communication Research 18: 737
CHAPTER CONTENTS
Introduction 29 The problem 30 Encouraging the patient to tell you about concerns and problems 30 Patients with special needs 31 Why did the patient seek your help? 31
The presenting problem 1. Merriman
Assessmentof the problem 31 History of the problem 31 Dimensions of pain 33 Techniques for assessing pain 34 Summary 36
INTRODUCTION Most patients consult a practitioner because they have concerns about or problems with their lower limbs. Problems are usually quite specific and focused. Patients may have problems with painful feet, an ingrowing toe nail or difficulty accommodating a bunion in footwear. Concerns are where the patient is worried or anxious about something. Patients may have concerns related to a problem, e.g. they are worried about an ulcer that is taking a long time to heal. Conversely, a patient may have concerns but no specific problems, e.g. a patient may be concerned that an asymptomatic mole on their leg may be a malignant melanoma. The role of the practitioner is to discover what are the patient's concernis) and problemts) in order that an effective management plan can be drawn up and implemented. This may involve anything from giving reassurance, e.g. that the mole is not a melanoma, to implementing a treatment plan aimed at resolving or reducing the effects of a specific problem, e.g. pain in the foot. During the assessment interview the patient should be given ample opportunity to express their concerns and talk about any problems they may have. The remainder of this chapter concentrates on acquiring information about the patient's presenting problemts). However, the practitioner should always remember it is also important to identify any concerns the patient may have. 29
30
APPROACHING THE PATIENT
THE PROBLEM What one person perceives as a problem another may accept as being normal. A major concern for one person may be a minor issue to another. Defining what is normal and acceptable, and what is abnormal or unacceptable and therefore a problem, is fraught with difficulties. When patients attend for their appointments they bring with them their own ideas of what is a problem and what is normal. A variety of factors can influence a patient's perception (Table 3.1). Fo~ example, if media coverage emphasised a link between verrucae and cancer of the cervix this might result in a number of females ~ho had previously ignored their verrucae seekmg treatment. Having a friend who has developed a malignant melanoma may make a person more vigilant for signs associated with this condition and prompt her to seek advice when previously she may have been oblivious to the situation. People from socioeconomic groups 1 and 2 are more likely to seek medical assistance than those from socioeconomic groups 4 and 5 (Townsend & Davidson 1982). It is important that the practitioner allows the patient to describe the problem in her own words. The practitioner's perception of the problem is not always the same as that of the patient. For example a mother may be concerne~ that her 3-year-old child has flat feet. The practitioner considers this to be normal for a child of that age. However, during the consultation, the Table 3.1 Factors that influence a patient's perceptions of what is normal and what is a problem
Age Gender Culture Socioeconomic base Knowledge base Previous experiences Views of family and friends Media Socioeconomic background Life expectations
practitioner notices a small verruca on the apex of the right second toe and suggests that it is treated. The mother accepts the treatment but leaves the clinic still concerned about her child's flat feet. The practitioner has failed to identify the mother's main concern. An effective solution would have consisted of advice and reassurance regarding the flat feet as well as treatment of the verucca.
Encouraging the patient to tell you about concerns and problems How can you encourage patients to tell you why they have sought your help? A whole range of factors can make it difficult for the patient to articulate the problem in words. Some patients may be frightened or embarrassed, others may be concerned that they are wasting your time and others that you will think they are silly to be concerned about a minor problem. It is essential that patients are made to feel that they are. not wasting your time and that you are genumely interested in their concerns and problems. Most patients present with discomfort or pain. For example, a patient may present with discomfort from a bunion rubbing on footwear. The patient may also be concerned about the appea.rance of the bunion and scared that she will develop a deformity similar to her grandmother's. A skilled practitioner will identify all the anxieties the patient is experiencing: the problems with the current discomfort, the difficulty in finding appropriate shoes to wear, the worry about the unsightly appearance of the bunion and the fear that it may get worse. It is important that you consider how best to start the conversation. Asking the patient 'What are you complaining on', 'What's the problem?' or 'What is it that's wrong with you?' are probably not the best ways to start. The last question may result in the patient responding 'That's what I've come here for you to find out'. 'How can I help you?' or 'Would you like to tell me about what concerns you?' may be preferable. Open questions should be used. The patient should ~ot feel rushed; avoid interrupting and puttmg words into the patient's mouth. Record in the
THE PRESENTING PROBLEM
31
patient's own words what she is concerned about and what she sees as a problem. Avoid medical jargon wherever possible. Having obtained an idea of the patient's concerns, it may help to find out if she has any thoughts as to the cause. Ask the reason for such conclusions. The answers to these questions may reveal whether patient and practitioner share the same view. When patients do reveal what is worrying them, avoid being judgemental and making comments such as 'Oh, that's nothing!' or 'I don't know why you are so worried!'. Remember it is a problem to the patient even if it is relatively innocuous to you. Patients may not reveal their real reason for coming to see you until they are just about to leave. This can be a source of annoyance to the busy practitioner. Do try and give the patient time even if it is at the end of the consultation.
Table 3.2
Patients with special needs
Assessment of the problem involves acquiring information about the history of the problem. The history must be taken logically and systematically. An assessment of the current level of pain and discomfort should also be undertaken.
Some patients may experience other difficulties in telling you about their concerns and problems than simply having poor powers of description. The patient may be deaf and dumb, have suffered a stroke, have a speech impediment or have learning or language difficulties. It is important you give these patients extra time. Avoid jumping to too many assumptions. If the patient can write, ask her to write down the nature of the complaint. Friends or relatives may be able to provide valuable details and information or act as interpreters.
Why did the patient seek your help? A variety of factors can influence why a patient has chosen to visit your practice. Table 3.2 gives the usual reasons for a patient choosing a particular practitioner. It is important to find out what made the patient choose you. For example, a patient who has been referred by a friend or relative may find it very easy to disclose her concerns to you. The friend/relative may have been very complimentary about your abilities. On the other hand, a patient who is seeking a second opinion
Reasons for a patient choosing a practitioner
Applied for treatment at their local health service Found your name in the yellow pages • Saw an advertisement • Noticed your plate outside the practice • Were advised by a friend or relative to seek your help • Were referred by another health practitioner, e.g. GP Are seeking a second opinion because they were unhappy with the response of the first practitioner
may want you to give a different diagnosis from the one given by the previous practitioner. As a result she may not disclose all the salient features of the problem. It is important to remember that outstanding legal claims for lower limb injuries may affect the patient's perspective.
ASSESSMENT OF THE PROBLEM
History of the problem History taking involves finding answers to a range of questions (Table 3.3). Many diseases can be identified by the pattern of symptoms they display. Research has shown that history taking
Table 3.3 patient
The history of the problem: questions to ask the
• Where is the problem? How did it start? How long have you had the problem? • Where is the problem? • When does it trouble you? • What makes it worse? • What makes it better? • What treatments have you tried? • Are you treating it at the moment?
32
APPROACHING THE PATIENT
can be more effective in diagnosing a problem than clinical tests alone (Sandler 1979). Where is the problem? Locating the problem is very important. Getting the patient to show you by pointing is the best way. If the patient has difficulty reaching the area, you may find it helpful to present an outline of the lower limb and ask her to mark the area affected. For example, pain may start in one area but then radiate to other areas. Some problems may have a precise location; others may be far more diffuse or have multiple sites. These variations may yield helpful clues to diagnosis. Isolating a localised area in the case of pain can be very helpful in differentiating enthesopathy from the more general discomfort associated with congestion of the heel pad. During the physical examination you may touch the area and attempt to elicit the symptoms in order to make sure you have isolated the area. Do not forget to tell the patient that this is what you are going to do. Palpation should use no more pressure than necessary to elicit symptoms and isolate the particular anatomy affected. It is essential that you record, either on a diagram or in words, the location of the problem and give an indication in the records as to whether it is well localised or diffuse. For example, a patient with plantar digital neuritis (Morton's neuroma) may complain of acute pain at one particular site, but may also describe a paraesthesia which radiates towards the apex of the toes. Diagrams may be preferable to written descriptions. Another practitioner treating the patient on a different occasion can see exactly where the problem lies. It is essential that dimensions of skin lesions are recorded. This approach allows progress to be monitored for improvement or deterioration. How did it start? It is important to identify how the problem started. The problem may have had a sudden or an insidious onset. For example, rheumatoid arthritis may have an acute sudden onset accompanied by raised temperature and severe joint pains, or more commonly a slow insidious onset with general aches and pains, which gradually get worse and more regular. Besides trying to locate the start of the condition, it is also important to record the symptoms the
patient initially experienced. For example, was there anything visible at the start, such as a rash, swelling or erythema? Were there any symptoms, e.g. the throbbing associated with acute inflammation? Initial symptoms may be different from the patient's current symptoms, especially if the condition had an acute onset but is now chronic. How long have you had the problem? It may be necessary to jog the patient's memory, especially if the problem started some time ago. Using family occasions such as weddings or births, national events or the season of the year may help the patient to pinpoint which time of the year it started. When does it trouble you? Some conditions may give rise to constant symptoms. Others may occur especially at night or during the day. For example, one of the distinguishing features of gout is nocturnal pain. Chronic ischaemia is associated with pain in the calf muscle (intermittent claudication) after a period of walking and the maximum distance the patient can walk prior to experiencing pain gives an indication of the severity of the problem. What makes it worse and what makes it better?
Some conditions may improve on rest, others can deteriorate. Patients may discover all sorts of ways to alleviate their symptoms, e.g. wearing particular shoes, adopting a different walking pattern. Such information can provide valuable clues. In instances where patients alter their gait because of a problem affecting one part of their foot or leg they may develop secondary problems elsewhere. It is essential that the practitioner identifies the original problem, as treatment for the secondary problem will not be successful until the initial problem is identified. What treatments have you tried? Are you treat· ing it at the moment? It is important to find out if
the patient has or is presently using any medications. Sometimes treatments can mask or alter the clinical features of a problem and make diagnosis difficult. For example, using 1 % hydrocortisone cream on a fungal infection of the skin may mask the inflammatory response and blur the distinctive border between infected and noninfected areas.
THE PRESENTING PROBLEM
It is important that you record the information the patient gives you in response to all these questions. All critical events should be dated.
Dimensions of pain Pain is a subjective, multidimensional phenomenon that can be affected by social and psychological factors. In the same way as individuals differ over what they perceive as a problem, individuals also differ when it comes to the assessment of their pain. Pain caused by apparently similar conditions affects individuals in very different ways. Practitioners should avoid making assumptions about the severity of pain an individual is experiencing. Patients vary in their abilities to cope with pain. Some are more than willing to complain about mild discomfort, whereas others make no complaint despite being in considerable pain. Tolerance and coping are subjective concepts that are difficult to quantify. A patient's state of mind and personal circumstances may make their pain worse or demand that they ignore it. For example, it is well known that runners may continue to run in a race despite having sustained an injury. The assessment of pain requires information about its character, distribution, severity, duration, frequency and periodicity. This information, coupled with the history of the problem and details of the patient's concerns, helps the practitioner to arrive at the correct diagnosis and draw up an effective treatment plan.
pain but as it becomes chronic and the disease process spreads it can affect a wider area. Radiating pain can result from the extent of the disease or from pain being referred from one site to another; for example, a trapped spinal nerve can lead to pains in the leg. Usually, referred pain does not get worse when direct pressure is applied to the site affected. However, if the pain has a localised cause it usually worsens when direct pressure is applied. Severity
Certain conditions give rise to severe pain, e.g. myocardial infarction. However, a patient's ability to tolerate and cope with pain differs so much that a description of the severity of the pain must be assessed alongside the other features. Duration
Pain may be fleeting or may be persistent. Ascertaining the duration of the pain can provide valuable information. For example, pain due to intermittent claudication may last a few minutes to half an hour. The pain associated with a deep vein thrombosis is persistent. These differences can be helpful in differential diagnosis. Frequency and periodicity
Some conditions lead to pain occurring in a regular pattern; others result in a less predictable pain pattern. It may be that the pain recurs infrequently or regularly.
Character
Pain can be superficial or deep. Pain arising in the skin often gives rise to a pricking sensation if brief or burning if protracted. Deep pain is more nebulous and is often associated with a dull ache. Patients may use a variety of adjectives to describe their pain (Table 3.4). Distribution
Pain may be localised, diffuse or radiating. Initially, a problem may give rise to localised
33
Table 3.4
Descriptors used to describe pain
Vice-like
Deep
Tooth ache
On touching
Throbbing
On weightbearing
Sharp
Intermittent
Stabbing Shooting Bursting
34
APPROACHING THE PATIENT
Techniques for assessing pain
•
There are many general pain measures but there are no foot-specific pain measures that are widely used. Various foot-specific measures have been developed, but these have not resulted in general use. For example, Budiman-Mak et al (1991) developed the Budiman-Mak Foot Function Index. This index was used in elderly patients with rheumatoid arthritis to assess activity limitation, perceived difficulty and pain. Weir (;Ot al (1998) in a survey of podiatrists found that 53% of podiatrists did not assess their patient's foot pain. This is of concern, as the accurate assessment of pain is critical for the identification of suitable and effective interventions. A range of techniques can be used to provide more objective information about the dimensions of pain experienced by a patient. Numerical pain rating scales. Different dimensions such as severity, frequency and duration can be assessed. For example, a patient may be asked to score the frequency of her pain using a 1-5 scale, where 1 signifies persistent, present all the time, and 5 is very infrequent, less than twice a week. Verbal descriptor scales (VDS). Descriptive scales can also be used. The following descriptors can assess severity: slight, quite a lot, very bad, agonising. Verbal descriptor scales are reliant on the ability of patients to use words that best describe their pain. It is not possible to compare the descriptors used by individual patients. Visual analogue scales (VAS). These scales can be used to assess the severity of pain. The technique involves asking the patient to indicate how severe their problem is. Figure 3.1 illustrates two different types of visual analogue scale. The VAS records the intensity of pain and is more useful for acute rather than chronic pain. The VAS has many advantages (Weir et aI1998):
•
• •
• • •
subjective measure of pain intensity clear to the patient what is being measured has face validity as it appears relevant to the patient quick and easy to administer requires minimal training of the patient
•
can be used in a variety of clinical settings including home visits high degree of reliability when used on the same patient useful indicator to compare 'before and after' situations (Bowsher 1994).
The VAS is not suitable for those with poor visual and motor coordination. It is thought to be unsuitable for elderly patients, as they may be confused and unable to adapt to the abstract thinking required (Hayes 1995). Rather than using a horizontal line a vertical line has been used, which is more akin to a thermometer (painometer). It has been argued that this approach facilitates the conceptualisation of pain increasing and may be easier to respond to than the horizontal scale (Herr & Mobily 1991). General pain questionnaires. The most wellknown general pain questionnaire is the McGill Pain Questionnaire, which is based on a 78-item structured questionnaire that provides information about present pain intensity and pain rating index. Use of this questionnaire indicates that a patient who describes their pain as frightening usually does not understand what is causing it (Melzack 1975). The use of this questionnaire has been criticised for the time it takes to complete and evaluate. Body-part questionnaires. These questionnaires usually relate to pain in a particular anatomical part, e.g. Boeckstyns (1987) developed a knee pain questionnaire. Charts. Charts can be used for patients to indicate where the pain occurs and, by using
A.c. ° 1 1
2
4
5
6
7
8
9
3
Figure 3.1 Visual analogue scales B. Descriptive.
A. Numerical
1°11
THE PRESENTING PROBLEM 35
different symbols, the type of pain that occurs (Fig. 3.2). Pain charts have been used as an aid to the psychological evaluation of patients with
low back pain (Ransford et al 1976). This method should be used with great caution and with the assistance of a suitably qualified psychologist in order to prevent incorrect conclusions being reached. Pain diaries. It may be helpful, especially if a patient is rather vague about the duration and frequency of the pain, to get the patient to complete a diary of the pain over a specific period of time. Figure 3.3 illustrates a pain chart. The categories used in the chart were devised by the Pain Research Institute, Liverpool. While pain diaries can be helpful, they may lead patients to focus on their problem and could even exacerbate it. The information gained from a patient presenting with a painful first metatarsophalangeal joint is shown in Table 3.5. The data used for this example suggest a diagnosis of gout. Laboratory tests and further assessments, i.e. medical and social history, may confirm this diagnosis.
Information gained from assessment of a patient with a painful first metatarsophalangeal joint
Table 3.5
The problem(s) The concern(s)
'I've got a very painful big toe. I can't sleep at night for the pain.' 'Do you think it is something serious?' 'Will I have to have
my Where is the problem? How did it start?
Numbness
xxxxx
Stabbing
11/ I ifill
Pins and needles 00000 Burning Figure 3.2
Pain chart.
AAAAA
foot off?' The big toe joint on my left foot. The pain started one night. I woke up in a lot of pain. My toe was bright red and throbbing. The next day it was really swollen. Itstarted about a week ago.
How long have you had the problem? When does it trouble you? It hurts all the time, especially at night. What makes it worse? If I knock it at all and when I walk on it. What makes it better? The pain eases a bitwhen I take a painkiller but when the tablet wears off the pain is just as bad again. What treatments have Just painkillers. I have been taking quite strong ones these you tried? last few days. Are you treating it at the See above. moment?
36
APPROACHING THE PATIENT
Mon
Tues
Thur
Fri
5 Excruciating 4 Very severe
6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 Figure 3.3
Wed
3 Severe 2 Moderate 1 Just noticeable
o No pain S Sleeping
Pain diary.
SUMMARY It is essential that the practitioner acquires a clear and accurate understanding of the patient's concerrus) and problems in order to devise an effective management plan. These terms have been emphasised in different ways in this chapter, although 'problem' and 'concern' may be used synonymously elsewhere. If the basic history part of the assessment concerning the presenting problem is inadequately dealt with or not undertaken the result of an inaccurate diagnosis occurring is all too clear to see. Some of these issues are emphasised in more detail in Chapter 5, which forms a prerequisite for systems analysis by functional enquiry and physical examination.
REFERENCES Boeckstyns M E H 1987 Development and construct validity of a knee pain questionnaire. Pain 31: 47-52 Bowsher D 1994 Acute and chronic pain and assessment. In: Wells P E, Frampton V, Bowsher D (eds) Pain management by physiotherapy, 2nd edn. ButterworthHeinemann, Oxford, pp 39-42 Budiman-Mak E, Conrad K J, Roach K E 1991 The Foot Function Index: a measure of foot pain and disability. Journal of Clinical Epidemiology 44: 561-570 Hayes R 1995 Pain assessment in the elderly. British Journal of Nursing 4: 1199-1204 Herr K A, Mobily P R 1991 Complexities of pain assessment in the elderly. Journal of Gerontological Nursing 17: 12-19
Melzack R 1975 The McGill Pain Questionnaire: major properties and scoring methods. Pain 1(3): 277-299 Ransford A 0, Cairns D, Mooney V 1976 The pain drawing as an aid to the psychologic evaluation of patients with low-back pain. Spine 1(2:6): 127-134 Sandler G 1979 Costs of unnecessary tests. British Medical Journal 2: 21-24 Townsend P, Davidson N 1982 Inequalities in health: the Black Report. Penguin, Harmondsworth, pp 76-89 Weir E C, Burrow J G, Bell F 1998 Podiatrists and pain assessment - a cross sectional study. The British Journal of Podiatry 1(4): 128-133
CHAPTER CONTENTS Introduction 37 Types of measurement 38 Quantitative measurement 38 Qualitative measurement 38 Semi-quantitative measurement 39 Integration of the three types of measurement 40
Clinical measurement c. Griffith
Selection of an appropriate measurement technique 41 The practitioner 41 The patient 41 Resources 41 Terms used in clinical measurement 42 Error in measurement 44 The clinical environment 45 Procedure 45 The equipment 45 The practitioner 47 The patient 50 Measurement evaluation exercise 51 Conclusion 52 Summary 52
INTRODUCTION Clinical measurement is closely intertwined with assessment and evaluation of the lower limb. The term 'measurement' refers to the discovery of the extent of an observation and to the result obtained. 'Assessment' and 'evaluation' are terms that refer to the process of interpreting the meaning of a measurement. Measurements are used for a number of reasons. They are fundamental to the processes of diagnosis, prognosis, prescription of treatment, case management and assessment of outcomes. The lower limb consists of a number of interrelated complex body systems. Bones, joints, muscles, nerves, blood vessels and other soft tissues all contribute to the health and function of the lower limb. With so many diverse structures and physiological functions in each of these body systems, it is not surprising that a wide variety of techniques have evolved to measure their performance. Some clinical observations are amenable to objective scientific measurement and others are not. To gain as much clinically useful information as possible about patients and their responses to treatment, both objective and subjective measurement methods can be employed. It is a matter of selecting the most appropriate technique for the particular circumstances.
37
38
APPROACHING THE PATIENT
TYPES OF MEASUREMENT There are three types of clinical measurement technique: • quantitative measurement • qualitative measurement • semi-quantitative measurement. All three types of measurement provide valuable but different types of clinical information.
of 0.75 em and a depth of 0.25 cm it would demonstrate that the ulcer was exactly half its previous dimensions. A wide range of equipment is available to measure clinical observations quantitatively. Instrumentation may be quite basic in its design, such as a rule or grid for measuring a lesion's size, or more advanced, such as a plantar pressure platform for gathering dynamic pressure versus time measurements.
Quantitative measurement Quantitative measurements measure quantity in the true scientific sense, being objective and typically consisting of two parts: a numerical value and a unit of measurement. The numerical value denotes the magnitude of an observation, defined against certain norms or standards called units of measurement. Units of measurement give a dimension to the numerical value. The language of scientific measurement is the Systeme International (51), also known as the metric system. Examples of 51 units of measurement appropriate to the clinical setting are kilograms (mass), metres (length), pascals (pressure), newtons (force), hertz (frequency), degrees (angle) and degrees Celsius (temperature). Because quantitative measurements have both magnitude and dimension they can be recorded and communicated exactly and concisely. All results obtained from quantitative measurements are classed as either interval or ratio levels of data. It is useful to know which category data falls into because it affects its interpretation. The numeric points or graduations on any quantitative measurement scale have equal intervals between them. This is an important feature because the results can be compared arithmetically. They can also be used in the most powerful inferential statistical tests. A clinical example will make the concept clear. If a plantar ulcer had a diameter of 1.5 em and a depth of 0.5 em this would convey the size of the lesion exactly. With treatment it would be hoped that the ulcer would resolve. The progress of the ulcer could be monitored over time. If on a subsequent occasion the ulcer was found to have a diameter
Qualitative measurement Qualitative measurements, as the name suggests, measure quality. They are subjective and essentially descriptive measures dependent upon human perceptions. This type of measurement results in an observation expressed in words. There is some debate as to whether qualitative observations are measurements in the true sense. Qualitative researchers argue a strong case for the legitimacy of these measures, pointing out the reductionist nature of quantitative results. They can provide extremely valuable clinical information where clinical features cannot be quantified. Returning to the ulcer example, qualitative measurement would include descriptions about the appearance of the ulcer. Qualitative descriptions of size could include 'large', 'small', 'deep' and 'shallow'. Comparison of size before and after a period of treatment can be indicated by using phrases such as 'larger than', 'smaller than', 'shallower than' and so on. Qualitative descriptions are clearly less exact in terms of magnitude than are quantitative measures. It would not be possible to say by how much the ulcer had decreased or enlarged over time. Quantitative measurement is clearly superior in the context of magnitude. On the other hand qualitative measures can make a major contribution to the understanding, description and communication of clinical observations. Considerable credence would be given to the colour of the ulcer's base and discharge, the shape of the lesion's edges and walls, and perhaps any odour noticed. Changes in these characteristics are clinically useful indi-
CLINICAL MEASUREMENT
cators of the status of an ulcer and whether it is improving or deteriorating.
Semi-quantitative measurement Semi-quantitative measurement techniques usually involve an association of quantitativ~ a~d qualitative methods. They are extremely vaned m their design and application and represent attempts to quantify clinical observations. where real quantitative methods are not appropnate, or as a cost-effective alternative. This type of measurement allows a common objective approach to obtaining, recording and communicating information. Results based on objective measurements tend to be modified and supported as more data are acquired (Calnan 1989). The following techniques exemplify some principles of semi-quantitative measurement.
39
Indices
Ankle-brachial, footprint and pulsility indices are commonly referred to in the literature. Each index is a ratio calculated from two quantitative values. The ankle-brachial index, for instance, is calculated by dividing the systolic ankle blood pressure by the systolic brachial pressure of the arm, e.g. 110/120 = 0.92. Indices are often referred to as quantitative measures. Arguably they may best be considered as semi-quantitative measures because they lack two important characteristics of quantitative measures: indices are dimensionless, as they have no units of measurement, and their numerical values cannot be treated arithmetically. For example, comparison of indices should be treated in a similar way to ordinal data. An ankle-brachial index of 0.4 indicates a severe ischaemic condition but it cannot be said that the condition is twice as bad as an index of 0.8.
Rating (grading) scales
Scores are allocated to each of a logical order of observations, with each score in some way being better or worse than another. The scale may indicate, for instance, the level of function of some system or activity, and range from normal function to absence of function. The Medical Research Council (MRC) grading for muscle strength (Table 4.1) allocates scores from 0 to 5 to classify function in patients with peripheral nerve damage. This is considered in Chapter 8 as part of essential orthopaedic assessment. The six ratings or gradings are placed in rank order of increasing muscle power, from 0 (no movement) to 5 (normal power). It is possible to record muscle power on a single occasion or, by taking a series of measurements, monitor improvement or deterioration in muscle power over time. This type of data is classed as ordinal data. It is important to remember that the differe~t score~ on an ordinal scale cannot be compared m an anthmetic way because the intervals between the points on the scale are not equal. With ref~rence to Table 4.1 it will be noted that the difference between 1 and 2 is not the same as the difference between 4 and 5. Also, a score of 4 is better than, but not twice as good as, a score of 2.
Nominal categorisation
Nominal categorisation is essentially a very simple classification system where an obser:ration is placed into one of two or more categones. The observation of interest could be either present or absent, and given arbitrary labels, perhaps A (present) and B (absent). For instance, a group of patients could be classified as hallux valgus present and hallux val~us absent. !?ata treated in this manner are descnbed as nominal, This is the most basic level of data and gives the least amount of detail about an observation. The
Table 4.1 Medical Research Council rating scale for muscle strength
Rating
Characteristic
o
No movement
1
Palpable contraction but no visible movement
2
Movement but only with gravity eliminated
3
Movement against gravity
4
Movement against resistance, but weaker than the other side
5
Normal power
40
APPROACHING THE PATIENT
hallux valgus condition is denoted simply as present or absent with no indication as to the severity of the condition. Only the simplest of arithmetic calculations can be carried out, and the data can only be used in the weakest types of statistical test.
Integration of the three types of measurement In practice, techniques selected from the three types of measurement may be used together to obtain a comprehensive clinical picture. This is illustrated in Table 4.2 by discussion of the results of measurements obtained for a patient presenting with walking difficulties. The relevant case history concerns a fall 1 year previously when a fractured pelvis was sustained. Following healing and discharge from hospital, the left leg and foot have become progressively weaker. Qualitative measurement. There appears to be a motor deficit in the anterior compartment of the leg. This may be due to impingement of a peripheral nerve related to the pelvic fracture. The lack of ankle dorsiflexion during the swing phase is being compensated proximally, by elevation of the trunk Table 4.2
Assessment results
Type of measurement
Method
Results
Qualitative
Visual observation of gait
Stance phase: The left foot slaps noisily against the ground at each step Swing phase: The left foot is plantarflexed, the hip and knee are flexed excessively and there is upper body sway to the right
Semi-quantitative
MRC muscle strength grading scale
The anterior muscle compartment score of 3 (i.e. movement against gravity)
Quantitative
Goniometric measurement
Active ankle dorsiflexion -10° Passive ankle dorsiflexion _5°
and excessive flexion of the hip and knee, so that the toes can clear the ground. Semi-quantitative measurement. A score of 3 on the MRC muscle strength grading scale. This indicates the level of impairment of the anterior muscle group. There is a deficit of motor power. The patient can dorsiflex the foot against gravity but not against resistance of the practitioner's hand. Quantitative measurement. Active dorsiflexion can be quantified with a goniometer, e.g. _10° dorsiflexion. The measurement of _10° dorsiflexion indicates that with maximum contraction of the anterior muscle group the foot still remains 10° plantarflexed at the ankle. With assistance from the practitioner the maximum range of dorsiflexion can be obtained (_5°). Although an additional 5° of dorsiflexion was obtained with the practitioner's help the foot remained plantarflexed at the ankle. Comparison with the unaffected ankle and known normal values will enable the practitioner to determine the extent of the reduction in ankle dorsiflexion and identify the probable cause. The calf may have shortened if there is a loss of power in the anterior antagonist muscle group. Future measurements can be used to quantify improvement or deterioration of ankle dorsiflexion. The example above demonstrates the value of integrating quantitative, semi-quantitative and qualitative types of measurement. A complete picture of the case can be constructed where evidence from one type of measurement complements another. Evaluation of the evidence then enables the practitioner to infer the cause of the changes in gait pattern with more than a reasonable degree of confidence. A thorough understanding of the problem gained in this manner enables an appropriate diagnosis and management plan to be decided. It could be argued that all measurements for the patient could have been quantitative. Gait analysis could have been recorded with video and the movements of the limb segments digitised to allow quantification. Muscle power could have been quantified with a dynanometer. Nevertheless, the example represents the most usual clinical situation where the practitioner
CLINICAL MEASUREMENT
may only have access to a goniometer. An important issue for consideration has now been raised. If a number of different measurement options are available, how does the practitioner select the most appropriate method?
SELECTION OF AN APPROPRIATE MEASUREMENT TECHNIQUE Selection of an appropriate measurement technique can be difficult, particularly for students with relatively little experience. Many factors influence the choice of a measurement technique. The three main factors are: • practitioner • patient • resources.
The practitioner Choice of measurement technique will be influenced significantly by professional and continuing education, past experience, personal beliefs, existing skills and a detailed knowledge of the patient's history. Consequently, some tests will be used more frequently than others. Knowledge and skills should be greater for those techniques used more often. Where less frequent or novel situations arise, a relevant measurement technique for the observation of interest must be selected. The MRC grading for muscle strength described earlier is suitable for patients with peripheral nerve damage causing muscle flaccidity. It is not a valid technique for patients with hypertonicity. To avoid the possibility of selecting an inappropriate technique, a sound theoretical knowledge of the measurement techniques under consideration is needed. The situations that might arise when selecting a measurement technique for a particular patient are: • seemingly similar observations (as above) may not be amenable to the same measurement technique • some observations can be measured by a number of techniques and there may be no particular clinical advantage in anyone technique
41
• it may be clear that one particular technique is preferred.
The patient Each patient is unique. Although there may be similarities between patients, no two cases are identical. An individual patient's characteristics will affect his suitability for different measurement techniques. Age, mental state, build, current medical status and medication, dietary and social habits are characteristics that should influence decisions about the choice of measurement. This may result in a modification to the measurement procedure, selection of an alternative technique, or even a decision not to perform the measurement at all.
Resources Resources have a significant influence on the availability of measurement techniques: funding, accessibility to equipment, professional skills, time and space will determine which measurements can be conducted. Practitioners will usually have facilities for routine measurements. However, ongoing technological advancements have facilitated the introduction of more sophisticated and cost-effective measurement equipment and techniques at the clinical level. Monofilaments help standardise the amount of pressure applied to the skin when carrying out neurological sensory testing because they buckle at a preset force. If a practitioner is interested only in peak pressures the Podotrack plantar pressure measuring device could be used as a much cheaper alternative to a computer-based pressure measurement system. Using this device, van Schie et al (1999) described a screening method for high pressures in 'at risk' patients with diabetes. Semi-quantitative measures are produced quickly by comparing relevant areas of the footprint with a calibration chart. Developments in microelectronics have provided many powerful measurement tools. Advances in digital photography have led to the production of high-quality images at a relatively low cost. Rajbhandari et al (1999) compared the
42
APPROACHING THE PATIENT
use of a digital camera for two-dimensional measurement of ulcer size with a more traditional approach with OpSite Flexigrid film. It was shown that digital imaging was easier, faster and subject to less variation.
Accuracy concerns a result that reflects the true value of the observation or phenomenon being measured.
surement technique is not repeatable, and consequently of limited clinical value. Many articles involving measurement question the repeatability of the techniques they have employed. Authors often make suggestions of how their work may be refined to improve repeatability, demonstrating that clinical measurement techniques are continually evolving. A novel procedure described by Prud'homme & Curran (1999) is one such example. A preliminary study of pain relief following treatment of corns was conducted. They found that the direct force that could be applied to the lesion with a hand-held algometer was greater after enucleation of the corn. This indicated that symptoms improved after podiatry treatment. The authors identified several potential sources of error. The rate of application and the uniformity of the applied force, the linearity of the instrument and variability in compliance of superficial tissues were all considered.
Precision
Reliability
Precision is the degree of refinement in a measurement and relates to the size of the intervals on the measurement scale. A rule with graduations of 1mm would allow greater precision than one with graduations every Smm. The intervals between the graduations on the measurement scale should always be appropriate for the observation of interest. If they are unnecessarily large and the measurement indicator falls between graduations the practitioner is forced to make an estimate of the reading, increasing the potential for error.
Reliability refers to consistency. It is the extent to which a measurement procedure produces similar results under constant conditions on all occasions. Repeatability is a measure of reliability. Clinical measures which quantify or semiquantify the extent of a problem can also be used to detect change. In this context the measurements are used both repeatedly and often by different people. Consequently, it is important to know how much any difference is due to real change and how much is caused by error (Wade 1992). In this way real improvements or deterioration in a patient's condition can be determined. Where the repeatability of a technique is known and variation in measurement falls within clinically acceptable limits, the practitioner can interpret the results and make clinical decisions with confidence. Reliability can be reduced by many factors. There are four main sources of uncertainty when comparing two or more results of the same measure:
TERMS USED IN CLINICAL MEASUREMENT The notion of an ideal measurement is one that is accurate, precise, repeatable, reliable and valid. To gain an awareness of both the value and limitations of contemporary measurement methods, an understanding of the terms associated with measurement is needed. Accuracy
Repeatability
Repeatability is determined by measuring the same patient with the same technique on two or more occasions and comparing the results. Inevitably there will be differences. An experimental research design can be used to determine statistically if any differences in repeated measurement results are large enough to be significant. A statistically significant difference between the results would indicate that the mea-
• variation in the patient's state
CLINICAL MEASUREMENT
• different instruments may vary, and one instrument may vary with time • the same observer may differ when measuring (intraobserver reliability) • different observers may differ when measuring (interobserver reliability). Patient's state. Differences in the patient's state between measurements may adversely affect the results. There may be changes in physical and mental states, motivation and fatigue levels. Ingestion of certain drugs and foods can influence the results of some tests. Some observations, e.g. blood pressure, can be affected by the time of day that they are taken. Instrument variation. Different examples of the same instrument may differ in performance. Booth & Young (2000) tested four types of commercially available 10-G monofilaments with a I-kg load cell using a standardised technique. Important adverse characteristics of the monofilaments were discovered that have implications for clinical use. Accuracy varied between the different products (8.1 ± 0.3 to 10.1 ± 0.4), where accuracy was defined as 10 g < 10%. The two most accurate types of monofilament were tested further. The longevity and recovery time were assessed. Only 50% of the monofilaments were accurate after 200 compressions, and recovery could take up to 24 hours with none regaining their original buckling force. Instrumentation may be affected by environmental changes such as variation in temperature and humidity. Intraobserver reliability. This factor concerns the variation between the results of repeated measurements obtained by the same observer. Statistical techniques are used to determine whether the differences in results are significant. Intraobserver variation can be attributed to many human characteristics. Variation in results may be due to differences in fatigue, motivation, stress levels and dexterity as well as to inconsistencies in technique. Intraobserver reliability differs from one individual to another; some practitioners demonstrate greater proficiency by obtaining more consistent results. Ideally one should be aware of
43
one's own measurement capabilities, and evaluation should be made at periodic intervals. Interobserver reliability. This factor concerns the variation between results of repeated measurements between two or more observers. The more observers are involved, the greater is the opportunity for differences to occur between them. There is evidence to show that intraobserver reliability is greater than interobserver reliability for many measurement techniques. For example, one study of repeated goniometric measurements concluded that reliability is increased if only one observer takes the measurements (Boone et aI1978). Simple, well-defined measurement techniques have been shown to be more reliable, presumably because observers can follow the procedures more closely. It is generally agreed that reliability of measurement improves with training, education and experience (Bovens et al 1990, Diamond et al 1989, Freeman 1990), but Payne & Richardson (2000) found that reliability of neutral and relaxed calcaneal stance position measurements did not improve with training in a group of undergraduate podiatry students. Where the same patient may be measured by different practitioners over time, the interobserver reliability between the individuals in the group should be known. This facilitates interpretation of the differences in results to interobserver error or to real change so that useful clinical judgements can be made. However, reliability should not be considered exclusively but in context with other measurement characteristics. Validity
Validity is concerned with whether the measurement actually does measure what it is supposed to measure (Bowling 1991). The idea of using footprints to link foot types to foot pathology has appealed to numerous researchers. The validity of footprint parameters used as indirect measures of the height of the mediallongitudinal arch has been questioned. The arch angle, footprint index and arch index described by various authors were compared with a direct measure of arch height (Hawes et al 1992). It
44
APPROACHING THE PATIENT
was concluded that these footprint parameters were no more than indices and angles of the plantar surface of the foot itself, and were invalid measures of arch height. All of the footprint parameters had previously been found to be reliable. Presumably this means that the footprint pattern and data measured from it are repeatable, but the indices derived cannot be assumed to be valid indicators of arch height. In a more recent study, Mathieson et al (1999) compared electronic static and dynamic footprint data using three different indices. Even though there were good correlations between the static and dynamic footprints, they concluded that the parameters calculated differed considerably. The concepts of sensitivity and specificity can be used to test validity. Sensitivity. Ability of a measurement or test to identify positive cases of the observation of interest. Specificity. Ability of the measurement or test to exclude negative cases of the observation of interest. A hypothetical example will illustrate the principles of sensitivity and specificity. If we suppose that the traditional approach to screening for hallux valgus is to X-ray each patient's feet, it might be thought beneficial to devise a method that does not depend on X-rays. Practitioners could be trained to use a new clinical measurement technique to determine whether patients have hallux valgus or not. If X-rays are assumed to give the true result, the practitioners' results could be compared with the X-rays. Two groups of symptomatic patients, one group with and the other without hallux valgus, would be selected from the X-ray results. If the practitioners' measurements were completely valid, then all the patients with a positive X-ray for hallux valgus and those with a negative X-ray would be appropriately identified. This never occurs in practice. There are always some false positives, i.e. those identified as having the condition when they do not, or false negatives, i.e. those identified as not having the condition when they do. Table 4.3 illustrates the main principles. Sensitivity is the percentage of patients correctly identified as having hallux valgus. Calculations
from the tabulated data show that the sensitivity is high, at 95%, indicating that most patients with hallux valgus were identified by the practitioners. The specificity is the percentage of patients without hallux valgus who were identified as not having hallux valgus. The specificity is low at 45%. This means that 55% of patients without hallux valgus were falsely diagnosed as having hallux valgus. The practitioners identified nearly half as many false positives (61) as true positives (129). With so many false positives identified the new clinical measurement technique would not be considered a useful screening test for hallux valgus. Acceptable values for sensitivity and specificity depend to some extent on the particular situation. Sensitivity of good tests is likely to be between 80% and 100%. Specificity should be in excess of 95%, particularly for screening tests where most of the population is likely to be negative; otherwise, more false positives than true positives may occur.
ERROR IN MEASUREMENT A significant problem with taking measurements is error. All results from measurements have two components: the true value of the observation of interest and an error component. The error component can be further divided into two parts. Random errors. These errors occur by chance and, because of their random nature, cannot be identified, controlled or eliminated. In research studies an appropriate research design and use of inferential statistical tests take random errors into account. This type of error will not be considered further. Table 4.3
Sensitivity and specificity X-ray results
Practitioners' measurements
Hallux valgus present Hallux valgus not present Total Sensitivity Specificity
Hallux valgus present 129
7 136
= 129/136 x 100 = 95% =
49/110 x 100
=
45%
Hallux valgus not present 61 49 110
CLINICAL MEASUREMENT
45
---------------------Systematic errors. These errors relate to potential sources of measurement error that can usually be postulated or identified. Once a source of error has been identified, action should be taken to try and reduce its occurrence. In all measurements conducted on patients there are five main potential sources of systematic error:
• • • • •
clinical environment procedure equipment practitioner patient.
The clinical environment Lighting must enable the practitioner to see clearly so that information can be gathered and recorded with ease. Careful planning of the lighting arrangements is essential. Assessment areas should be well lit so that vital clinical features are not obscured. Special lighting facilities are sometimes necessary. For example, a light box is essential for clear interpretation and measurement from radiographs. Clinical space is often at a premium. It is essential that there is sufficient space for a selected measurement procedure to be undertaken. Gait analysis requires a walkway of at least 6 m, but preferably 10 m, so that a representative walking style can be seen. The ambient clinic temperature should be controlled at 21°C ± 2°C. This is not only important for the comfort of the practitioner and patient but is also essential for vascular and neurological measurements. Significant adverse effects on vascular measurements are caused by factors that change peripheral arterial resistance (Johnson & Kassam 1985). Background noise, interruptions and distractions during consultations should be kept to minimum levels as they impair concentration, communication and patient relaxation.
Procedure Standardisation of measurement techniques reduces the potential for error in measurement. Consequently, it can improve repeatability, reli-
ability and accuracy and, in most circumstances, validity. Standardised techniques have clearly specified procedures which must be followed closely. Unfortunately, standardisation cannot remove error completely. The extent of measurement error that is clinically acceptable is determined by the type of observation, research and statistical methods. Where different techniques measure the same type of observation, the one that produces the least error should be selected. An understanding of the size of the error enables practitioners to understand the limitations of the techniques they use so that they can interpret their clinical measurements realistically. Research reports should be read with care. Special attention should be paid to the quality of the procedure before adopting a new or alternative technique. It is important to balance gains in accuracy, precision, reliability and validity claimed, particularly if they are marginal, with clinical costs and benefits to patients.
The equipment Equipment indirectly involved with measurement can affect results. The examination couch should permit a variety of positions to suit the many types of examination that may be performed. Practitioner fatigue will be reduced if the appropriate height of couch is used or if the height can be adjusted. Instrumentation used directly on the patient should be comfortable to handle and easy to use. Calibration of instrumentation is a fundamental but essential process of measurement. The purpose of calibration is to minimise the error caused by the measurement equipment. It is a process of setting up the instrument so that its readings are as accurate as possible throughout its range of measurement. The instrumentation is tested against known standards. Calibration curves are plotted so that the accuracy can be determined and the error quantified. An example will make things clear. To calibrate weighing scales they must be placed on a horizontal surface. The measurement indicator is aligned to zero.
46
APPROACHING THE PATIENT
Known loads are applied at intervals throughout the measurement range. A comparison is made between the output reading on the measurement scale and the known load (kgf). By plotting the two variables a calibration curve can be produced. Ideally, the curve would be linear throughout the measurement range. If not, errors are identified and the measurement tolerances calculated and specified. Where instruments are precalibrated, errors may be specified as a percentage error within the measurement range. For example, most manufacturers of equipment for measuring foot pressure claim an accuracy within 10%. It is therefore not possible to know whether marginal differences are real or due to error. Recalibration of equipment should be carried out periodically, following manufacturers' guidelines. Some instruments are designed to measure a series of values during cyclic activities. Pressure transducers measure pressure under discrete areas of the foot. A transducer located under the second metatarsal head would measure progressive loading and unloading pressures applied during one gait cycle. Static calibration of the transducer is carried out by applying a series of known loads and then progressively removing them. A graph is produced in the form of a loop. This phenomenon is known as hysteresis. Figure 4.1 shows that the output readings for known loads differ between the ascending and descending modes. A dashed line drawn from the horizontal axis at 5 kg loading, to intersect with each curve, shows the disparity in output readings during ascending and descending modes at points (a) and (b), respectively, on the vertical axis. Hysteresis is defined as the maximum difference in any pair of readings, one in the ascending mode and one in the descending mode, during one cycle of calibration and is expressed as a percentage of fullscale output (Dainty et al 1987). The performance characteristics, particularly of electronic equipment, must be suitable for the intended purpose. Before obtaining a system to measure plantar pressures it is vital to have a clear idea of the information the practitioner wishes to collect, a profile of the patients to be
studied and where the equipment will be used (West & Barnett 1999). As there is no perfect system, practitioners must weigh the advantages and disadvantages of each and choose the one that most closely matches their requirements. Platform systems. Platforms measure the unshod foot. The patient is unencumbered by the attachment of wires but they must target the platform accurately. Only data from one foot (with a one-platform system) can be gathered from each walk. In-shoe systems. These systems seem attractive as they measure pressure at the foot-shoe interface and many sequential measures of right and left feet can be obtained from one walk. Attachment of wires to the patient, whether it is to a data pack worn by the patient or by an umbilical arrangement to a computer, may affect the patient's gait. The in-shoe environment is hostile to transducers: humidity, temperature and bending effects may lead to the production of artifact pressure readings or premature failure.
200 C'O
~
(a)
.~ 160
'"0
~ C
(b)
Ql
» Loading > Unloading
.sE 120 (J)
c
80
40
o
5
10
15
Load kg
Figure 4.1 Hysteresis from elastomeric pressure transducer. Pressure is recorded against load applied for static calibration for a VP1 pressure pad. The plot shows loading and unloading as two curves. The hysteresis is represented by the gap between the curves (adapted from Tollafield 1990).
CLINICAL MEASUREMENT
The type of pressure transducer used by each system should also be considered. Resistive, piezoelectric and capacitance sensors convert mechanical signals into electrical signals for processing. The characteristics of transducers must be matched to the type of data the practitioner wishes to collect. The principles of hysteresis and repeatability have already been described. Spacial resolution, sampling frequency and dynamic response are other important characteristics described below. Practitioners requiring further information are directed to a very comprehensive review of pressure sensors by Urry (1999). Spacial resolution. This refers to the number of sensors in one square centimetre in a homologous matrix. If spacial resolution is low, smaller anatomical features such as the lesser metatarsal heads or toes may be missed because there is greater spacing between individual sensors. Some in-shoe methods do not have a matrix of sensors but a number of separate or discrete transducers giving a very low spacial resolution. Problems with accurate placement of these transducers on the skin overlying the metatarsal heads was highlighted by comparison with data from the F-Scan high-resolution matrix insole sensor (Lord et aI1992). The discrete transducers were shown to be out of position by as much as 20mm. Sampling frequency. This refers to the number of times each individual sensor is scanned during data collection. Events which occur very quickly in the stance phase of gait may be missed if sampling frequency is low. For walking a sampling frequency of 50 Hz (50 times per second) is appropriate, whereas a higher sampling rate of 200 Hz is required for running. The dynamic range. This should permit sampling of both high and low pressures expected in the patient cohort. If this were not the case then pressures occurring outside the range would be missed. Particular care is required with neuropathic patients as very high pressures are likely to saturate the sensors at their upper limit. Conversely, the soling materials in trainer footwear may be very shock absorbent and very low pressures may be missed.
47
Measurement instrumentation is prone to ageing and wear and tear, increasing the potential for error. Obvious changes in mechanical instruments may be noticed where the measurement scale becomes difficult to read, or its components become damaged or loose. Electronic components tend to age less noticeably. Noise is generated by electrical circuitry and it tends to increase as equipment ages. Everyday examples of noise include the background hum of audio speakers, or interference with visual information on a display monitor, rather like the lines produced on a television screen as an unsuppressed motor vehicle passes by. It is important to ensure that intrinsic noise produced by the instrumentation and electrical equipment in the vicinity does not interfere significantly with measurements. Careful use, monitoring and maintenance of equipment is essential if clinically useful measurements are to be obtained.
The practitioner Errors made by the practitioner can be reduced if a good practitioner-patient relationship is established. Effective communication and patient compliance is essential. Efficiency and confidence are usually transferred to the patient through verbal and non-verbal communication channels. Instructions given to patients must be clear, so that they understand exactly what they must do. Children, ethnic minorities and the physically and mentally disabled usually require more careful and considered approaches. Adequate time must be allowed for the measurements to be completed satisfactorily. Qualitative measurements
Qualitative measurements involve an internal appreciation and processing of the observations made. Qualitative techniques are subjective in nature and mainly involve the perceptions of sight, hearing and touch. Some senses are more acute in some individuals than in others. Different life experiences, age, education, state of health or mind and environmental factors will affect these perceptions. Qualitative measurements
48
APPROACHING THE PATIENT
are therefore more prone to bias errors in practitioners than are quantitative measures. An awareness of the problems associated with subjectivity is important, because different individuals may perceive the same observation in different ways. Often, preconceived ideas lead to mistakes, as illustrated in Figure 4.2A. When first seen most people read the legends incorrectly as 'Paris in the spring', 'Once in a lifetime', and 'Bird in the hand'. We have a tendency to see what we expect to see and ignore what we consider unimportant. This may happen in diagnosis, when a feature associated with a particular condition is given greater importance than it should receive and assumptions lead to a rapid, poorly considered diagnosis. It may be that other clinical features indicate a different pathology but these may go unnoticed, be ignored or be
regarded as of little significance. By remaining as objective as possible and adopting a systematic problem-solving approach this tendency will be reduced. The brain may interpret the same observation in different ways, as shown in Figure 4.2B. The same observation may not only differ between individuals but differ in the same individual on different occasions or as they make a closer study. Some quantitative measurement procedures depend on some subjective decisions by the practitioner. The location of pulses, anatomical landmarks and alignment of instrumentation all rely on subjectivity, thus increasing the potential for bias error. It is important to be aware of the subjective qualitative factors which may impair objective measurement so that attempts can be made to control them. Vision
A
B Figure 4.2 A. The three triangles. Failure to see the duplicated words is common. We see only what we want to see B. Howald is she? Some observers see a young woman, others an old woman. The chin and neck of the former become the nose and mouth of the latter and vice versa (Munro & Edwards 1990).
Vision plays a major part in measurement. During clinical training a student practitioner develops a 'trained eye'. Recognition of pathology develops with time and practice into a fine skill, where even subtle signs may alert the practitioner to a problem. Visual information may be impaired if lighting is inadequate. Apart from the more obvious difficulties caused where lighting levels are low, shadows cast on to a part of the limb may adversely affect subjective aspects during biomechanical examination. Eyeballing describes a subjective visual technique that can be used to align joints before measurement, or to identify midpoints across skin surfaces as goniometric reference points. Passive examination of the subtalar joint range of motion and neutral position is considered to be an important element in understanding abnormal function of the foot. Inappropriate placement of reference lines, particularly on the curved surface of the back of the leg, is more likely to occur if one side of the leg is adequately lit and the other is not. A true vertical bisection of the leg may not be obtained. Consequently, the proportions of inversion and eversion contributing to the total range of motion,
CLINICALMEASUREMENT 49
and determination of the neutral position, would be incorrect. Parallax error. A potential source of measurement error, parallax error is particularly associated with joint position and movement. Parallax is an apparent difference in position or direction of an object caused by a change or relative change of observation point, as shown in Figure 4.3. Viewing an object or patient at right angles will eliminate parallax error. Measurement error will increase if the measurement instrument is not aligned with the plane of motion. A 90° alignment must also be ensured
,
,
,
I I I I I I I
I I I I I I I
I I I
I
I I
I
A
tpJctfJC F B
C
o ABC
Figure 4.3 The effect of parallax on observation of the midpoint of the posterior aspect of the leg and heel A. Inappropriate positioning of the patient's leg leads to parallax error B. With the patient's leg and the practitioner's eyes correctly aligned parallax error is eliminated C. Inappropriate positioning of the practitioner's eyes leads to parallax error D. The actual and apparent midpoints obtained from the relative eye and leg positions adopted in diagrams A, Band C.
when reading analogue measurement scales. Parallax error up to 3° was noted in one study (Griffith 1988). The patient must be advised on the need for appropriate clothing if normal indoor dress inhibits a particular observation. Body parts must be clearly exposed where feasible. Shorts and a T-shirt, for example, allow a relatively uninhibited view of posture and movement. Touch
Touch involves many forms of direct and indirect (using instrumentation) physical contact with patients. During clinical examinations various components of the lower limb may be pushed, pulled, pressed, squeezed and twisted. The amount of force used is determined by feedback through the practitioner's proprioceptive pathways, the patient's response, sound and visual information. It is very subjective. The force used to test joint ranges of motion will need adjustment for different patients and different joints. Fluidity of the joints, muscle tone and the weight of the limb will all influence the force required to examine a joint effectively. Instruments used in neurological and vascular assessments must be applied to the appropriate area and with an appropriate amount of force. Using neurotips, tuning forks and cotton wool requires a systematic approach and correct technique. For instance, inadvertently tickling the patient with cotton wool when testing for light touch will be interpreted through pain pathways rather than light touch receptors, invalidating the result. Measurement of lower limb temperature can be obtained quantitatively with a digital thermometer, but most practitioners rely on touch. The practitioner's hand temperature will influence his appreciation of the patient's limb temperature. This can be demonstrated with a simple experiment. If both hands are inserted into a bowl of tepid water, having previously had one in cold and the other in hot, a clear difference in appreciation of temperature of the tepid water by each hand is noted. The subjective appreciation of temperature is therefore a relative phenomenon and a
50
APPROACHING THE PATIENT
patient's limb will feel warmer to a practitioner with cold hands than one who has warm hands.
Vowden (1999), Grasty (1999) and Baker & Rayman (1999).
Hearing
The patient
Doppler ultrasound units generate audible signals representing the velocity of blood flow. A normal arterial audio spectrum is triphasic, representing forward, reverse and forward blood flow. Considerable experience is necessary to develop the appropriate listening skills so that normal and abnormal sounds can be distinguished. However, artifacts can be produced if the application of the probe over the blood vessel is imprecise so that an artery and a vein are isonated simultaneously or the probe is not held steady. If the probe angle is incorrect the signal strength is reduced. A probe with an appropriate frequency must be selected, depending on the depth of the vessel of interest, so that adequate signal strength can be obtained. Connection to a computer with appropriate software enables the blood flow to be seen as a waveform providing a visual trace for interpretation (Fig. 4.4). Arterial and venous flows, pathological states and artifacts can be confirmed, with a permanent record produced for filing in case notes and inclusion in correspondence. Excellent accounts of the clinical use of Doppler ultrasound in the detection of peripheral vascular disease have been written by
The patient may be responsible for measurement errors for many reasons. General intelligence, mental disorder, anxiety, impaired hearing or sight or language difficulties could affect his ability to understand what is required. Patients may not follow instructions or respond appropriately or truthfully. They may be non-compliant. If the patient is anxious or annoyed, increased adrenaline (epinephrine) levels will elevate the basal metabolic rate, e.g. the pulse rate could be increased. Patients who are emotionally distressed may be less able to comply with the requirements of some types of measurement procedure. It is not unusual for patients to find difficulty in relaxing during passive biomechanical measurements. Joint ranges and fluidity of motion can appear reduced. Forefoot varus or supinatus could be erroneously diagnosed if the patient fails to relax the tibialis anterior muscle, because contraction of this muscle inverts the forefoot relative to the hindfoot. Neurological sensory tests may require a verbal response from the patient so that the result can be obtained. Assuming that the test is applied correctly, the patient must interpret the
Doppler waveforms
Velocity
===t>
Forward bloodflow
<;::===
TIme
Reverse bloodflow Triphasic waveform
Biphasic waveform
Monophasic waveform
Figure 4.4 Diagrammatic representations of Doppler output showing normal and abnormal waveforms (adapted from Baker & Rayman 1999).
CLINICAL MEASUREMENT 51
sensation felt, which relies greatly on patient subjectivity. Vibration sensation may be tested with a variety of instruments. Higher vibration perception thresholds (VPTs) are associated with large peripheral nerve dysfunction. A 128 Hz tuning fork is quick and simple to use but is unsatisfactory for measuring the threshold at which vibration becomes perceptible. The Rydel Seiffer tuning fork is a cost-effective alternative, allowing semi-quantification. The biothesiometer and neurothesiometer allow quantification but take more time. Cassella et al (2000) used a neurothesiometer to demonstrate that enhanced VPT readings were obtained (i.e. the ability to perceive vibration was improved) at the medial malleolus, first metatarsophalangeal joint and thumb in a mixed group of normal subjects 1 hour after caffeine consumption. It is therefore important to enquire whether caffeine-containing drinks have been consumed before commencing neurological testing. The psychological state of the patient may influence measurement results. Painful diabetic neuropathy is associated with significant depression (Tesfaye & Price 1997). These patients may, or may not, have normal peripheral nerve function. It is important to consider the effect that depression might have on any sensory test results obtained. If the patient is embarrassed, poorly motivated, self-conscious or in pain, his walking pattern and speed may be altered. If patients are required to visualise and step on a specific target such as a force or pressure platform, they may adjust walking speed or step length before activating the transducer mechanism, giving an atypical result. Controlling walking speed is a major factor in foot pressure measurement. Step length, cadence, stance phase gait and peak pressure have all been shown to vary with walking speed (Hughes et aI1991). Some underlying pathological conditions can influence the measurement results. Doppler ultrasound waves are attenuated when they pass through fat, haematoma or scar tissue, resulting in a weak signal. Calcification of arterial walls prevents collapse of the artery when a blood pressure cuff is applied. The abnormally high reading obtained would invalidate the ankle-brachial
index. Digital vessels are less likely to calcify and toe pressures could be taken instead.
MEASUREMENT EVALUATION EXERCISE Many commonly used measurement techniques have been shown to be prone to substantial error. Problems with kinetic, goniometric, vascular and neurological measurement techniques applied to the lower limb have been regularly reported. A paper about vascular assessment has been selected from the literature so that the measurement issues raised in this chapter can be applied. The paper simply looked at whether or not four observers could agree on the presence of two pedal pulses. Following a summary of the research findings the potential sources of error and possible solutions to minimise errors will be considered under the five main headings: clinical environment, procedure, equipment, practitioner and patient. The reader may also be interested in trying this exercise on papers of their own choice. Dorsalis pedis and posterior tibial pulses are traditionally palpated to evaluate the blood supply to the foot. An investigation of observer variation in assessment of dorsalis pedis and posterior tibial pulses by palpation and Doppler ultrasound was conducted (Magee et al 1992). The study concluded that palpation of pedal pulses in patients with arterial disease is subject to substantial error. A consultant, registrar, senior house officer and a nurse measured 33 claudicants and five controls. Following palpation of the claudicants' pulses all observers agreed on the presence of a dorsalis pedis pulse in 67% of limbs, and the presence of the posterior tibial pulse in 53% of limbs. In contrast, with Doppler ultrasound, all observers agreed on the presence of a dorsalis pedis pulse in 58% of limbs, and the presence of a posterior tibial pulse in 78% of limbs. The poor reliability of these measurement procedures has obvious clinical implications and warrants further consideration. The clinical environment. Temperature and background noise levels must be controlled to reduce the potential for error. High and low temperatures
52
APPROACHING THE PATIENT
alter peripheral resistance and may have had an influence on the ease of detection of the pulses if the ambient temperature was not controlled. The procedure. Standardised procedures for each measurement should be followed. The subject's acclimatisation time before measurements are taken is particularly important: at least 10 minutes' rest is required. The patients should be placed in the same position for each measurement. The Doppler probe must be applied at the correct angle (60°) against the direction of blood flow to obtain a clear signal. It is possible to occlude superficial vessels with the Doppler probe if too much pressure is applied. This may explain why there was lower agreement between practitioners over the presence of the dorsalis pedis pulse when the Doppler probe was used. The equipment. If different Doppler units were used, even of the same make and model, there could be differences in the results they produce. If a Doppler unit's battery charge is low, weaker sounds may not be heard. Systems that can provide a permanent visual record of the vascular flow waveform would help confirm the presence of a pulse, and also allow identification of artifacts, and venous sounds. The practitioner(s). The ability of different observers to detect pulses could be due to a variety of factors. More experienced observers may be more skilful and better able to locate weak pulses. There may be differences in sensitivity in the fingertips between observers. When searching for the dorsalis pedis artery with the Doppler probe it may lose contact with the skin and coupling gel so that ultrasound waves are not transmitted. Sufficient quantities of an ultrasound gel must be used. Noise and artifacts caused by movement of the Doppler probe could lead to error because of distortion of the audio spectrum. The patient. Anatomical variations, blood vessel abnormalities and oedema could cause variation in results between examiners.
Conclusion The exercise above has identified problems associated with clinical observations that are measured by many practitioners on a daily basis.
Some suggestions of changes to the measurement techniques have been made which hopefully would reduce the margins of error. Measurement of clinical observations is an essential part of clinical practice, but it is not a simple step-by-step process. The knowledge provided by research leads to continual improvements in standardisation of techniques and advancements in instrumentation. It is important that practitioners develop a scientific and systematic approach to clinical measurements and appreciate the value and limitations of their measurements. It is only by the diligent application of measurement techniques that the body of scientific knowledge will increase and further improvements in the standards of clinical practice will occur.
SUMMARY Measurement may be conceptualised as being quantitative or qualitative in nature or a mixture of both. Data may be considered to have ordinal, nominal or graded (scores) properties which provide variable conclusions about the data collected from measurement. This chapter has attempted to highlight a number of the many pitfalls for the unwary that may lead to significant error. Ongoing research has identified many of the causes of error in measurement, particularly those associated with the subjective application of techniques to simple as well as sophisticated techniques. Error in measurement is affected by many influencing factors. Compensation for error is possible up to a point. When using any sophisticated equipment it is essential that it is applicable to the purpose required, is calibrated and has known tolerances of error that can be accounted for. The terms 'validity', 'reliability' and 'repeatability' contribute to a better understanding from any type of equipment used. Different observers can affect results and therefore strict protocols in practice are essential to obtain the most helpful information. The practitioner must therefore attempt, using the type of knowledge highlighted in this chapter, to minimise the potential for poor data collection and erroneous interpretation that could lead to false results.
CLINICALMEASUREMENT 53
----------------------------------REFERENCES Baker N, Rayman G 1999 Clinical evaluation of Doppler signals. The Diabetic Foot 2: 22-25 Boone D C, Stanley P A, Lin C M, Spence C, Baron C, Lee L 1978 Reliability of goniometric measurements. Physical Therapy 58: 1355-1360 Booth J, Young M J 2000 Differences in the performance of commercially available lO-G monofilaments. Diabetes Care 23: 984-988 Bovens AMP M, van Baak M A, Vrencken J G PM, Wijnen JAG, Verstappen F T J 1990 Variability and reliability of joint measurements. American Orthopaedic Society for Sports Medicine 18: 58-63 Bowling A 1991 Measuring health: a review of quality life measurement scales. Open University Press, Buckingham Calnan J S 1989 Handling the original idea. In: Mathie R T, Taylor K M, Calnan J S (eds) Standardizing biomechanical testing in sport. Human Kinetics Publishers, Champaign, Illinois, p 87 Cassella J P, Ashford R L, Meakin J 2000 The effect of caffeine on neurothesiometer readings. The Diabetic Foot 3: 18-20 Dainty D, Gagon M, Lagasse P, Orman R, Robertson G, Sprigins 1987 Recommended procedures. In: Dainty D, Norman R (eds) Standardizing biomechanical testing in sport. Human Kinetics Publishers, Champaign, Illinois, p 87 Diamond J E, Mueller M J, Delitto A, Sinacore D R 1989 Reliability of a diabetic foot examination. Physical Therapy 69: 797-802 Freeman A C 1990 A study of the intertester and intratester reliability in the measurement of resting calcaneal stance position and neutral stance position. Australian Podiatrist June: 10-13 Grasty M S 1999 Use of the hand-held Doppler to detect peripheral vascular disease. The Diabetic Foot 2: 18-21 Griffith C J 1988 An investigation of the repeatability, reliability and validity of clinical biomechanical measurements in the region of the foot and ankle. Project report No. 88/25. University of Westminster, London Hawes M R, Nachbauer W, Sovak D, Nigg B M 1992 Footprint parameters as a measure of arch height. Foot and Ankle 13: 22-26 Hughes J, Pratt L, Linge K, Clark P, Klenerman L 1991 Reliability of pressure measurements: the EMED F system. Clinical Biomechanics 6: 14-18 Johnson K W, Kassam M S 1985 Processing Doppler signals and analysis of peripheral arterial waveforms problems
FURTHER READING Edwards C R W 1990 The history and general principles governing physical examination. In: Munro J S, Edwards C R W (eds) Macleod's clinical examination. Churchill Livingstone, Edinburgh, p 11
and solutions. In: Bernstein E F (ed) Non invasive diagnostic techniques in vascular disease, 3rd edn. C V Mosby, St Louis, ch 7, P 55 Lord M, Reynolds D P, Hughes J R 1992 Foot pressure measurement: a review of clinical findings. Biomedical Engineering 8: 283-293 Magee T R, Stanley P R, al Mufti R, Simpson L, Campell W B 1992 Should we palpate foot pulses? Annals of the Royal College of Surgeons of England 74: 166-168 Mathieson I, Upton D, Birchenough A 1999 Comparison of footprint parameters from static and dynamic footprints. The Foot 9: 145-149 Munro J S, Edwards C R W 1990 Macleod's initial examination. Churchill Livingstone, Edinburgh Payne C, Richardson M 2000 Change in the measurement of neutral and relaxed calcaneal stance positions with experience. The Foot 10: 81-83 Prudhomme P J, Curran M J 1999 A preliminary study of the use of an algometer to investigate whether or not patients benefit when podiatrists enucleate corns. The Foot 9: 65-67 Rajbhandari S M, Harris N D, Sutton M et al1999 Digital imaging: an accurate and easy method of measuring foot ulcers. Diabetic Medicine 16: 234-243 Tesfaye S, Price D E 1997 Therapeutic approaches in diabetic neuropathy and neuropathic pain. In: Boulton A J M (ed) Diabetic neuropathy. Marius Press, Carnforth, pp 159-181 Tollafield D R 1990 A reusable transducer system for measuring foot pressures. A study of the reliability in a commercial pressure pad. Department of Health and Life Sciences, Coventry Polytechnic, Coventry, pp 31-48 Urry 1999 Plantar pressure measurement sensors. Measurement Science Technology 10: R16-R32 van Schie C H M, Abbott C A, Vileikyte L, Shaw J E, Hollis S, Boulton A J M 1999 A comparative study of the Podotrack, a simple semiquantitative plantar pressure measuring device, and the optical pedobarograph in the assessment of pressures under the diabetic foot. Diabetic Medicine 16: 5-10 Vowden P 1999 Doppler ultrasound in the management of the diabetic foot. The Diabetic Foot 2: 16-17 Wade D T 1992 Measurement in neurological rehabilitation. Oxford Medical Publications, New York, p 20 West S, Barnett S 1999 Plantar pressure measurement: which system? The Diabetic Foot 2: 3, 108-110
CHAPTER CONTENTS Introduction 57 The purpose of the medical and social history 57 THE MEDICAL HISTORYAND SYSTEMS ENQUIRY 59 The medical history 59 Current health status 59 Past and current medication 60 Past medical history 62 The family hist~ry
The medical and social history 1. Reilly
62
Personal social history 63 Home circumstances 63 Occupation 63 Sports and hobbies 63 Foreign travel 64 The systems enquiry 64 The cardiovascularsystem 64 The respiratory system 66 The alimentary system 67 The genitourinary system 68 The central nervous system 70 The endocrine system 71 The locomotor system 73 Summary 73
INTRODUCTION A patient's medical and social history has a number of implications for the diagnosis and management of lower limb problems. Conditions affecting the lower limb may be caused by, or have ramifications for, the patient's general health and well-being. Taking a history is a highly skilled exercise that requires practice to achieve and maintain competency. Information gleaned from a skilled enquiry is the first step towards making the correct diagnosis, directing further investigations and facilitating the formulation of an appropriate treatment plan. A properly taken medical and social history is concerned with the patient as a whole and not just the lower limb complaint with which the patient has presented. The approach outlined in this chapter forms the basis of a holistic approach to patient care.
The purpose of the medical and social history History taking is as important as any diagnostic test or physical examination. It is the least expensive of all investigations and time spent on obtaining a thorough history is rarely wasted. Diseases or abnormalities of the lower limb often present with a history of signs and symptoms which will allow the practitioner to make a provisional diagnosis. Once a history has been taken, physical examination and diagnostic tests 57
58
SYSTEMS EXAMINATION
can then be employed to confirm the diagnosis and stage the severity of the condition. An example of a provisional diagnosis that can be obtained through history taking is Morton's neuroma, which describes a painful condition of the forefoot caused by a benign enlargement of (usually) the third common digital branch of the medial plantar nerve, located between and often distal to, the third and fourth metatarsal heads. The syndrome is a mechanical entrapment neuropathy, with degenerative changes resulting from stretch and compression forces. Initially, the patient may experience paraesthesia (pins and needles) or numbness in the ball of the foot. In more advanced cases, the pain may be sharp or throbbing, and classically radiates distally into adjacent toes. The pain is worse on exercise and is relieved by rest and massage. By the time the patient attends for consultation the symptoms will often have been present for 4-6 months, and be gradually worsening such that symptoms come on more quickly with exercise and take longer to subside with rest. Such a history points to a diagnosis before the practitioner even needs to examine the patient and will indicate what confirmatory tests need to be employed. Diagnosis can then be confirmed by point tenderness between the metatarsal heads followed by the use of diagnostic nerve blocks. A comprehensive history taking therefore helps the practitioner to formulate a diagnosis and develop and implement an effective management plan. An inadequate history of the patient's health status may have the following consequences. 1. The patient is placed at risk. Inappropriate or unsafe treatment may be provided because of inadequate knowledge of the patient's medical history. Performing nail surgery on a patient with a prosthetic joint may produce a bacteraemia, which could infect and then loosen the joint replacement. Bacteraemia in patients with a history of infective endocarditis or rheumatic valvular disease may lead to bacterial growth on the previously damaged heart valves or endocardium. Invasive or operative treatment on haemophiliacs or patients taking anticoagu-
lant therapy requires special consideration because of the likelihood of very slow blood clotting and haemorrhage. If drugs are prescribed (or recommended) in the absence of a detailed medical history an existing condition may be exacerbated. For example, aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) may precipitate asthma attacks. Inadequate knowledge of the patient's existing medication could lead to adverse reactions with newly prescribed drugs. 2. The practitioner is placed at risk. Inadequate history taking may place the practitioner at risk when handling tissue products. A history of jaundice should alert the practitioner to the possibility of hepatitis, whereas a history of haemophilia, blood transfusion, foreign travel or intravenous drug use may place the patient and thus the practitioner at risk from the human immunodeficiency virus (HIV) and hepatitis B. 3. Poor treatment outcomes. Treatment may fail or cause the patient's presenting condition to worsen because inadequate history taking has prevented accurate diagnosis of the presenting foot complaint. Swelling on the top of the foot in a 39-year-old woman, which develops after an ankle sprain, may be nothing more than inflammation-related oedema. If the practitioner finds there is also a history of cigarette smoking, use of the contraceptive pill and recent immobilisation, the differential diagnosis would include deep vein thrombosis, a potentially life-threatening condition that requires quite different management to an ankle sprain. 4. An increased risk of clinical emergencies.
Individuals may be placed at risk by certain treatments, drugs or procedures that are normally considered routine. Adequate history taking will identify those patients who have previously developed adverse reactions. Requesting an inappropriate antibiotic prescription from a GP for a penicillin-sensitive patient may result from poor history taking. Hypersensitivity reactions to dressings, for example zinc oxide strapping, or medicaments, for example iodine, may be known to the patient and should be noted.
THE MEDICALAND SOCIAL HISTORY
THE MEDICAL HISTORY AND SYSTEMS ENQUIRY A systematic approach to history taking will ensure that the practitioner covers all relevant areas in the enquiry process. The medical history and systems enquiry presented is based upon the hospital assessment or clinical clerking system. Findings recorded with this system (Table 5.1) will determine the need for further clinical or laboratory investigation and indicate the patient's suitability for a range of treatments. Many departments give their patients a health questionnaire (see Appendix, pp. 77-78) to complete prior to seeing the practitioner again. The use of questionnaires gives the patient time to consider his answers and reduces the amount of time spent during the consultation on taking a medical history.
THE MEDICAL HISTORY
Current health status Before history taking begins, the practitioner will gain some impressions about the patient's current health status from simple observation. Patients should be observed as they enter the consulting room. Diseases of nerves, muscle, Table 5.1
The medical history and systems enquiry
Part 1. The medical history Current health status Past and current medication Past medical history Part 2. Family history Part 3. Personal social history Home circumstances Occupation Sports and hobbies Foreign travel Part 4. The systems enquiry - CRAGCEL Cardiovascular system Respiratory system Alimentary system Genitourinary system Central nervous system Endocrine system Locomotor system
59
bone and joints may all manifest in patients' gait or posture. For example, upper and lower motor neurone lesions may cause an ataxic gait where coordination and balance are impaired. Patients with acute foot or leg pain will walk with a limp as they try to 'guard' the injured part. Patients with chronic foot disorders will shuffle rather than stride because a propulsive gait will cause more forefoot pain. Gait disorders in children are best visualised as the child walks into the room to meet the practitioner; a child will often become self-conscious when asked to walk on demand. The consultation should begin with a handshake as considerable information can be gleaned from this simple contact. Wasting of the thenar eminence and intrinsic musculature of the hand occurs with rheumatoid arthritis and with some genetic disorders, such as Friedreich's ataxia and Charcot-Marie-Tooth disease. Disorders of skin and nails may manifest themselves in the hand: for example, psoriasis and eczema may cause hypertrophy and anhydrosis of the skin; pulmonary or cyanotic heart disease may cause clubbed nails. The patient's facial appearance and expression is also of interest to the practitioner. The tense tired face of those in chronic pain will appear similar to those suffering from depression. Parkinson's disease or long-term use of psychotropic drugs will reduce facial expression, whereas the thyrotoxic patient, with characteristic protruding eyes, will be striking for their 'angry' appearance. Patients on long-term steroid therapy can develop a 'moon' face. Hypothyroidism will lead to a loss of hair from the outer third of the eyebrows, baldness and coarse, thickened facial skin. Acromegaly, an excess of growth hormone due to a disorder of the pituitary gland, will give rise to a heavy 'lantern' jaw. Cyanotic blue lips are a sign of poor cardiac function. Small plaques of brown lipid under the eyes, seen with hyperlipidaemia, are associated with atherosclerosis. Obvious weight abnormalities affect the lower limb and should be noted on first meeting the patient. Obesity is associated with recalcitrant heel pain and other postural symptoms. Seriously underweight patients may be suffering from a
60
SYSTEMS EXAMINATION
range of systemic conditions or they could be poorly nourished due to alcoholism, drug abuse or anorexia nervosa. Fatigue and weight changes are symptoms of many systemic illnesses and are always worthy of note, especially if weight change appears to be rapid. The following questions will reveal important information about the patient's general health: • Are you feeling well? • Are you under the doctor or consultant for any treatment currently? • Do you sleep well at night? • Do you feel tired during the day? • Is your weight stable? • For women, could you be pregnant? In general, patients who are unwell are not good candidates for involved procedures or treatments that are likely to demand close compliance on their behalf.
Past and current medication Information about the patient's previous and current drug therapy can provide useful information about the patient's health. Patients should be asked if they are currently taking, or have taken in the past, any tablets or medicine or used any ointments or creams that have been Table 5.2
prescribed by their doctor. It is not uncommon for a patient to have used prescribed drugs for many years with no clear understanding as to why he has taken them. The practitioner should refer to the British National Formulary (BNF) or another pharmacological text if unfamiliar with any drugs that the patient is taking. Large doses or prolonged use of certain medications can be associated with significant ad verse drug reactions with relevance to the lower limb. Most drugs produce several effects, but the prescriber usually wants a patient to experience only one (or a few) of them; the other effects may be regarded as undesired. Although most people use the term 'side effect', the term 'adverse drug reaction' is more appropriate for effects that are undesired, unpleasant, noxious or potentially harmful. Prednisolone, commonly used in the treatment of rheumatoid arthritis, can reduce skin thickness and impair wound healing. Bendrofluazide, a useful diuretic for the treatment of cardiac failure or hypertension, can cause hyperuricaemia, which may result in goutlike symptoms. Warfarin, an oral anticoagulant used for the treatment and prophylaxis of venous thrombosis and pulmonary embolism, increases clotting time and has obvious implications if surgical treatment is planned. Other examples of adverse drug reaction can be found in Table 5.2.
Side effects of drugs affecting the lower limb
Drug
Therapeutic use
Side effects
Beta-blockers Calcium channel blockers Salbutamol The contraceptive pill Propanolol Chloramphenicol Colchicine Metronidazole Indomethacin ACE inhibitors 4-quinolones Corticosteroids Aspirin Frusemide Nalidixic acid
Hypertension Hypertension Asthma Contraception Hypertension Infection Gout TB infection Arthritis Hypertension Infection Inflammation Pain management Hypertension Infection
Coldness of extremities Ankle oedema Peripheral vasodilatation Increased risk of DVT Paraesthesia Peripheral neuritis Sensorimotor neuropathy Sensorimotor neuropathy Sensorimotor neuropathy Muscle cramps Damage to epiphyseal cartilage Osteoporosis, skin atrophy Purpura Bullous eruptions Bullous eruptions
THE MEDICAL AND SOCIAL HISTORY
Patients should also be asked if they are currently taking or have taken in the past any tablets or medicine or used any ointments or creams which they have purchased from the chemist. Self-prescribed medication is of interest to the practitioner not least because the quantities used may be quite variable, with the possibility of chronic overdosing. For example, repeatedly exceeding the recommended daily dosage of vitamins A and D supplements may give rise to ectopic calcification in tendon, muscle and periarticular tissue. The practitioner should be alert to the possibility of a patient developing an allergy or adverse reaction to medications used during treatment. In particular, details of any adverse reactions, either by the patient or any member of the patient's family, to previous local anaesthetic injections and other drugs (e.g. penicillin) should be sought and explored. A type I hypersensitivity reaction, which leads to anaphylactic shock, is of most concern. It is not known why some individuals are predisposed to anaphylaxis, though genetic mechanisms are certainly involved since there is a strong familial disposition. In some individuals, contact with certain allergens will stimulate the production of an antibody of the immunoglobulin E (lgE) class, which has the ability to adhere to mast cells in tissues and basophils in the circulation. When an individual sensitised in this way is exposed on a second occasion to the allergen, the allergen combines with the IgE antibodies on the surface of the mast cells. This causes immediate destruction of the mast cell, which releases its contents, specifically histamine, serotonin, platelet-activating factor and slow-reacting substance. If the exposure to the allergen is systemic, hypotension, bronchiole constriction, laryngeal oedema, swelling of the tongue, urticaria, vomiting and diarrhoea may follow. Fatal anaphylaxis is rare. When it does occur it usually follows entrance of an antigenic drug such as penicillin to the circulation of a sensitised individual. Insect stings are also an important cause of anaphylactic fatality. Of particular concern to the podiatric practitioner is the overdosage of local anaesthetics,
61
which can lead to convulsions as a result of central nervous system stimulation. This may be followed by a profound drop in blood pressure and life-threatening cardiovascular system depression. In such circumstances oxygen must be administered to support the patient. The risk of such a clinical emergency can be minimised by adhering to the maximum safe dose values for the various local anaesthetic agents and always having oxygen available. A local type I hypersensitivity reaction may be caused by local anaesthetic agents. The skin around the area of the injection shows an immediate, localised inflammatory reaction. Use of all recreational drugs should be recorded. Amphetamines, like many mood stimulants, will have a vasoconstrictive effect. The use of injectable drugs places the patient at risk of hepatitis and HIV. Long-term or heavy use of tobacco can affect wound healing due to the immediate vasoconstrictive effect of nicotine as well as the long-term effect of increased platelet adhesiveness and atherosclerosis. Tobacco smokers are also at greater risk of bronchitis, asthma and lung cancer. Heavy alcohol consumption can affect the peripheral sensation, immune response, postoperative wound healing and the metabolism of local anaesthetics, as well as having implications for treatment compliance. Alcohol consumption is generally measured in units. One unit of alcohol is equivalent to one glass of wine, a single measure of spirits or half a pint of beer. More than four units of alcohol per day is noteworthy. Unfortunately, it is likely that those patients abusing alcohol are least likely to be forthcoming about their alcoholism. Where alcohol abuse is suspected, questions should be asked in a permissive manner: • Although you may not be drinking a lot now, what about in the past? • Was there ever a time when you were drinking more heavily? The patient should also be asked about dry retching in the morning, as this is a symptom of alcohol withdrawal. Drinking before 10 a.m. is an important finding, as it is associated with chronic alcoholism.
62
SYSTEMS EXAMINATION
Past medical history The past medical history consists of information about previous lower limb problems and the treatment received as well as details about any problems that have affected the patient's general health. The nature of previous podiatric treatment, the name of the practitioner, details of relevant investigations such as X-rays, and the patient's view of the treatment's success should be recorded. This information may prevent the repetition of tests or treatments which have previously been ineffective. The patient should then be asked: • Have you been off work due to illness for more than 1 week in the last 6 months? • Have you ever been admitted to hospital? • Have you ever had an operation? • Have you ever been under the care of a consultant or a hospital specialist? • Did you have any major childhood illnesses? Hospital records can provide this information but they are not always available. These questions will hopefully prompt the patient into recollecting any previous incidents of illness or surgery. Questioning should follow a sequence that moves from the patient's childhood to the present. Hospitalisations for operations or injuries should be recorded and any complications noted (Case history 5.1). In females, a particularly common procedure is hysterectomy, which has implications for the lower limb in that the effect on hormone balance can lead to prema-
Case history 5. 1 A 23-year-old secretary presents with pain in the first metatarsophalangeal joint. The pain is aching in nature severe and worse on exercise. The range of motio~ of the joint is reduced, with painfUl crepitus evident on dorsiflexion. Further enquiry elicits a history of trauma from a fall in a horse-riding accident 2 years ago. Diagnosis: Traumatic arthritis. An X-ray revealed a compression fracture to the head of the first metatarsal, which has predisposed degeneration of the joint.
ture osteoporosis. This may manifest clinically as vertebral collapse, leading to spinal deformity and possibly causing referred neural compression symptoms. Injuries may often appear to be unrelated to the patient's presenting complaint but it must be remembered that the lower limb functions as one unit and if one component of the unit is damaged, it can lead to compensations elsewhere in the lower limb. If a patient is still under the care of a hospital consultant it is prudent to inform the consultant before any treatment is given that may affect other body systems.
THE FAMILY HISTORY A pedigree chart to record details of major illnesses and lower limb problems of the immediate family may be used (Fig. 5.1). Many cardiovascular, alimentary, neurological and endocrine disorders can be inherited. Enquiring
RH\A A\W Aged
Died heart attack aged 62 Hallux valgus
71
0 0 ~
MALE FEMALE PATIENT
A'o/V ALIVE & WELL • Figure 5.1
DEAD The pedigree chart.
THE MEDICAL AND SOCIAL HISTORY
about the medical history of the immediate family may reveal a predisposition to a range of systemic diseases, a good example of which is non-insulin-dependent diabetes. It can also be of value to record the cause of death of immediate family. Certain lower limb pathologies can be inherited or appear to have a familial predisposition, especially diseases that are neurological in nature such as Friedreich's ataxia and Charcot-Marie-Tooth disease. The diagnosis of a patient presenting with difficulties in walking will be affected by a positive family history of a condition such as these. All forms of spina bifida should be noted even if the problem has been labelled as spina bifida occulta (impaired gait, pes cavus and plantar ulceration have been found to appear late in cases of spina bifida occulta). The ethnic origin of the patient should also be noted. Sickle cell anaemia may affect people of African or West Indian descent. Thalassaemia, another haemolytic anaemia, can affect patients from Mediterranean and Southeast Asian regions. The patient should be asked if anyone else in the family has suffered from leg or foot problems. This information will help to determine the inherited nature of any foot condition and, in the case of pes cavus, hallux valgus and lesser digit deformity, could indicate the degree of severity that the patient's presenting condition may eventuallyachieve.
PERSONAL SOCIAL HISTORY Home circumstances It is important to assess the patient's home situ-
ation. With some types of treatment patients are required to reduce their activity level to a minimum, change dressings or administer treatments at home. In the case of surgical treatment the practitioner must establish who is going to transport the patient to and from surgery and who is going to assist him through the immediate postoperative recovery period. Lack of home support may rule out certain forms of treatment.
63
A 27-year-old female sales executive attended the clinic with heel pain. The pain was on the anteromedial aspect of the plantar heel pad and had , been present for some time. Point tenderness at the origin of the medial band of the plantar fascia was elicited. Examination revealed a hyperpronatory foot type. Diagnosis: Plantar fasciitis. However, the patient was required to wear fashionable court shoes for her employment. She was unwilling to compromise on the style of footwear she wore and provision of a suitable orthotic was impossible. The patient was subsequently referred for cortisone injections.
Occupation A patient's occupation may be a contributory cause of the lower limb problem and may influence what treatment can be given (Case history 5.2). Some patients may experience particular difficulties in taking time from work to attend for treatment. The nature of the work should be determined and special footwear requirements should be noted. The types of surface that the patient stands and walks on during the day can be exciting factors. Bare concrete floors will exacerbate chilblains, whereas patients whose occupation involves standing on ladders will often suffer from chronic medial longitudinal arch pain.
Sports and hobbies Active sports people may make the association between their sport and a lower limb problem: those who participate in occasional sporting activities and hobbies may not. Patients who participate in infrequent sporting activities may not think to inform the practitioner of these activities. However, these patients are often more prone to injury because they are often not fit and do not follow a warm-up and warm-down regimen. These patients are more likely to develop hamstring or calf muscle injury due to poor flexibility. Details of any sporting hobby should, therefore, be sought from the patient. The assessment of the sports injury patient is considered in detail in Chapter 15.
64
SYSTEMS EXAMINATION
Foreign travel Details of foreign travel should be recorded in case the patient has acquired an infection. In particular, travel to tropical countries and any foot injuries sustained while walking barefoot should be recorded (Case history 5.3).
THE SYSTEMS ENQUIRY The systems enquiry seeks to discover if the patient suffers from any systemic conditions that may affect the patient's lower limb problem and unearth any signs and symptoms, which the patient has not complained of spontaneously. The systems enquiry may reveal significant symptomatology which the practitioner is either inexperienced in or unqualified to diagnose. In such circumstances the patient should be informed that a second opinion is recommended. The subsequent referral for a second opinion should be seen as part of the patient's overall treatment plan. All the body systems are worked through in a set order, which can be remembered using the acronym 'CRAGCEL' (see Table 5.1). The systems enquiry involves asking questions that will seem, to the patient, to be quite unrelated to the lower limb problem. It is important, before the enquiry begins, that patients are advised that the purpose of the questions is to ensure that there are no
Case history 5.3 A 23-year-old male attended clinic following 6 months working as a volunteer in India. For some of the time he walked around barefoot and recalls occasionally having to remove splinters and small stones from his sole. He presents with a pruritic, inflamed lesion with a central black dot, under the free edge of the hallucal toe nail of his left foot. Diagnosis: A tropical parasitic infection of the jigger or sand flea, Tunga penetrans. Originally a native of the New World, it is now widely disseminated in Africa and Asia. A fertilised female, gaining access to human skin, burrows beneath the surface where it becomes engorged with blood. The site of penetration is usually found under the toe nail of the barefooted patient, but can occur on the plantar aspect of the foot. The central black dot is the flea's abdominal segments. Treatment is by incision and prophylactic antisepsis.
general health problems that may be causing the lower limb condition or that may influence the type of treatment considered.
The cardiovascular system A history of cardiovascular disease should be taken with respect to systemic, peripheral and haematological disease states, followed up by a review of symptomatology. To determine the presence of systemic cardiovascular disease the patient should be asked if they have ever had: • • • • • •
angina a heart attack high blood pressure heart failure irregular heart rhythms rheumatic fever.
Ischaemic heart disease refers to two clinical syndromes, angina pectoris and myocardial infarction (MI). Angina occurs as a result of atherosclerosis of the arteries to the myocardium and often coexists with atherosclerosis of the arteries to the lower limb. MI is a gross necrosis of the myocardium due to interruption of the blood supply to the area. Hypertension is a risk factor for many life-threatening conditions such as MI, renal failure and cerebral vascular accidents (strokes). An increase in blood pressure is usually asymptomatic and many hypertensives do not realise they have the condition until they develop symptoms (transient ischaemic attacks) or routine screening reveals a diastolic blood pressure above 90 mmHg. Practitioners should routinely take their patients' blood pressure, not least because the stress caused by treatment or examination may provoke a clinical emergency in an uncontrolled hypertensive. Congestive heart failure (CHF) results from the inability of the heart to sufficiently supply oxygenated blood to the tissues. Causes include valvular heart disease, myocardial disease and hypertension (Case history 5.4). Arrhythmias may present as bradycardia (slow heartbeat) or tachycardia (fast heartbeat) with varying degrees of irregularity. Certain rhythms such as ventricular tachycardia predispose to cardiac arrest.
THE MEDICAL AND SOCIAL HISTORY
Case history 5.4 A 65-year-old female patient attended the podiatry clinic complaining of weak muscles in her legs. She had noticed the weakness for some time, stating that if her symptoms continued to deteriorate she would have to give up her job as a school playground supervisor. Further questioning revealed that her weakness could more accurately be described as fatigue and heaviness of her legs walking to and from work. The patient had also noticed that climbing stairs brought upon a tight squeezing pain in her chest. Sitting down relieved the pain but prolonged sitting tended to make her ankles swell. Diagnosis: Congestive heart failure. This condition can have a direct effect upon the ability of the muscles to function under strain.
Rheumatic fever is a febrile disease occurring as a sequel to group A haemolytic streptococcal infections. It is characterised by inflammatory lesions of connective tissue structures, especially of the heart and blood vessels, and predisposes to bacterial endocarditis. Having recorded disease states of which the patient is aware, enquire further about any systemic cardiovascular symptoms. Ask the patient if they: • • • • •
suffer from chest pains are ever short of breath experience palpitations find that their ankles swell are prone to fainting.
The most important cardiovascular symptom to elicit is chest pain because of the range of pathologies responsible for its occurrence. The differential diagnosis includes MI, angina pectoris, pneumonia, pericarditis and oesophageal reflux. The pain of angina is tight and pressure-like, precipitated by exercise and relieved by rest, and usually lasts for only a few minutes. The pain of an MI is similar in nature but is more intense, lasting from 30 minutes to 3 hours. Dyspnoea (shortness of breath) may occur as a result of pulmonary oedema. In CHF there is an inadequacy in the supply of oxygenated blood. To compensate for this, first the heart rate
65
and then the volume of blood filling the left ventricle increases. Because it takes longer to fill the left ventricle, the pressure in the whole cardiac pulmonary system 'backs up', causing pulmonary congestion, reduced blood gas exchange and eventually pulmonary oedema. Pulmonary oedema and shortness of breath are, therefore, signs and symptoms of left-sided heart failure. Right-sided heart failure is almost always associated with left-sided heart failure and gives rise to peripheral oedema. The right side of the heart can no longer deal with the volume of venous blood returning to the heart for transportation to the lungs and a 'back up' of pressure occurs in the systemic circulation, resulting in transudation of fluid into the peripheral connective tissue. Gravity will force most of the transudate to collect bilaterally in the feet and ankles. Initially, the patient will notice that the swelling reduces at night when the legs are recumbent. In chronic right-sided heart failure, the peripheral oedema will eventually be infiltrated by fibrous tissue that cannot be reduced by elevation. Syncope (fainting) is a transient loss of consciousness. Cardiac disease such as arrhythmias and aortic stenosis can cause syncope by decreasing the cerebral blood supply. Other less-specific systemic cardiac symptoms include fatigue and decreased exertional tolerance. To determine the presence of peripheral vascular disease the patient should be asked if they have ever had: • • • •
a thrombosis or blood clot night cramps an ulcer on their leg or foot varicose veins and/ or surgery.
Whereas cardiac problems may affect lower limb perfusion, peripheral vascular disease can occur in the absence of cardiac symptoms. The general enquiry may have already revealed sleeping problems, but the cardiovascular system investigation should determine whether sleep disturbance is due to cramping pain in the legs. Nocturnal cramps are a consequence of increased permeability of the microcirculation that accompanies the warming of the legs under bedding. In
66
SYSTEMS EXAMINATION
the presence of any impairment of the venous system, toxic metabolites will accumulate, increasing carbon dioxide tension while lowering oxygen levels. Muscle ischaemia follows, manifesting as a painful tautness of muscle fibre. Also enquire further about any peripheral vascular symptoms. Ask the patient if they: • • • •
get cramp at night get muscle cramps while walking suffer from chilblains notice their feet change colour if it is particularly cold.
All the above factors are signs and symptoms of peripheral vascular disease. Assessment of the vascular status of the lower limb is covered in detail in Chapter 6. To determine the presence of haematological disease patients should be asked if they have: • anaemia • haemophilia • any other blood disorder. Haematological disorders should be considered. Anaemia occurs when red blood cells or haemoglobin content decreases because of blood loss, impaired production or excessive destruction of red blood cells. Tissue hypoxia results from anaemia and this in turn leads to cardiovascular and pulmonary compensations. Clinical symptoms depend upon the severity and duration of the anaemia. Severe anaemia is associated
Table 5.3
with weakness, vertigo, headaches, tiredness, gastrointestinal complaints and CHF. Sickle cell disease is an inherited condition that can affect persons of African or West Indian descent. Those who inherit the gene from both patients have more than a 75% chance of developing the condition. Sickle cell individuals are prone to ulceration around the malleoli, a complaint more characteristic of older people with venous insufficiency. In most cases, patients will know whether they have sickle cell anaemia, as from early childhood the digits of the hands and feet tend to swell and are very painful. The use of tourniquets carries an increased risk of complication. A tourniquet causes relative anoxia and this in turn causes occlusion in small vessels due to changes in the haemodynamic qualities of red blood cells, which may lead to small vessel infarction and possibly digital gangrene.
The respiratory system To determine the presence of known systemic respiratory disease the patient should be asked if they have ever had (Table 5.3): • • • •
asthma chronic bronchitis emphysema pulmonary embolism.
Asthma presents as a dry, wheezing cough accompanied by dyspnoea. Exercise, infection or
The clinical features and implications of respiratory diseases
Disease
Clinical features
Clinical implications
Asthma
Dyspnoea, wheezing, cough
Attacks may be provoked by exercise, infection or stress. May be treated with long-term corticosteroid therapy
Chronic bronchitis
Cough with expectoration of sputum for at least 3 months in 2 successive years
Commonly a history of cigarette smoking carries an accompanying risk of peripheral atherosclerosis
Emphysema
Dyspnoea with varying degrees of exertion
Sufferer will have limited exercise potential; in time will lead to right-sided heart failure and peripheral oedema
Pulmonary embolism
Pleuritic chest pain and haemoptysis
A life-threatening condition which may follow prolonged postoperative bed rest
THE MEDICAL AND SOCIAL HISTORY
stress may provoke attacks. Patients may be treated with long-term corticosteroid therapy. Chronic bronchitis is associated with a history of cigarette smoking and peripheral atherosclerosis. Emphysema causes dyspnoea with varying degrees of exertion. In time the sufferer will develop right-sided heart failure and peripheral oedema. Pulmonary emboli may cause pleuritic chest pain and haemoptysis. It is a life-threatening condition that may follow prolonged postoperative bed rest. Having recorded disease states of which the patient is aware, enquire further about any respiratory symptoms. Ask the patient if they have: • • • •
shortness of breath chest pain related to breathing or exercise a cough coughing up of blood.
Dyspnoea is one of the most common symptoms of respiratory disease. Respiratory illness associated with pulmonary inflammation and pressure on the pleural surfaces will lead to chest pain. The pleura (the serous membrane covering of the lungs and thoracic cavity) is richly endowed with sensory nerve endings. Stimulation of these nerves will cause a knife-like pain, which is intensified by deep breathing. Pulmonary hypertension and infection are commonly associated with chest pain. Coughing is a protective mechanism employed to clear foreign material or mucus. The causes of coughing can be: • mechanical, e.g. inhalation of dust • inflammatory, e.g. mucous membrane oedema • non-pulmonary, e.g. pulmonary embolism • malignancy, e.g. dry cough • drug-induced, e.g. ACE inhibitors. The coughing up of bloody sputum is always considered an abnormal finding. Massive haemoptysis is a life-threatening condition which follows pulmonary neoplasm, mitral stenosis, pulmonary hypertension or tuberculosis (Case history 5.5). A social and environmental history may also be relevant. The patient should be asked if they:
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Case history 5.5 A 19-year-old male presents with poor hygiene and digital ulcers on his left foot. The ulcers arose from neglected chilblains. A social history reveals that he has been homeless since leaving school some years ago. A cough of 2 months' duration is noted with the sputum yellow in colour and tinged with blood, indicating hasmoptysls. Diagnosis: Tuberculosis. A chest X-ray revealed a number of calcified granulomas and a small cavity consistent with a tuberculosis infection.
• have ever had asthma or an allergy to any airborne substances such as house dust or pollen • use any chemicals at work • are exposed to chemical vapours • live or work with people who smoke cigarettes.
The alimentary system Gastrointestinal (GI) disorders are extremely common and have many implications for the lower limb and its treatment (Case history 5.6). To determine the presence of GI disease the patient should be asked if they have ever had: • • • •
any diet or bowel problems toothache or gum swelling indigestion or stomach ache stomach problems, e.g. upset stomach after taking aspirin.
Dental disease presents a bacteraemic risk, gastric ulcers will contraindicate NSAIDs and analgesic preparations, whereas liver disease will impair metabolism and may affect the safe denaturation of many drugs, including local anaesthetics. The enquiry should start with questions about the mouth and then progress to the stomach, intestines and bowel (Case history 5.6). The patient should be asked if he is currently suffering from toothache or gum disease. This question will establish the presence of any potential nidus of infection in the oral cavity. Information about previous dental care may reveal that the
68
SYSTEMS EXAMINATION
Case history 5.6 A 32-year-old male presents with low back pain that was worse at night or after inactivity. He also suffered from heel pain and neck pain, a loss of appetite and had moderate weight loss. Examination revealed joint pain and swelling in the shoulders, knees and ankles. Diagnosis: Ankylosing spondylitis. This condition was confirmed by X-rays and blood tests. It is a progressive inflammatory disease that usually affects young adult males. There is often a positive family history with 95% of patients carrying the HLA-B27 antigen.
patient has to take antibiotics before undergoing dental treatment. A known side effect of the NSAID class of drugs is gastrointestinal irritation. This is significant when these drugs are used for prolonged periods. Whereas the majority of people will suffer occasional indigestion, a history of dyspepsia provoked by small doses of alcohol or analgesics will indicate gastrointestinal sensitivity. The character of the abdominal pain, its location, precipitating factors and pain radiation should be considered. The pain from gastritis is burning or gnawing in character and is localised to the epigastrium but may radiate to the back. Gastritis pain is precipitated by ingestion of alcohol, aspirin or fasting for long periods. Food consumption will rapidly relieve the pain. Chronic gastritis will eventually progress to peptic ulcerative disease. Pain arising from the biliary tract leads to a full or cramping sensation in the upper quadrant just behind the right rib cage. It will occasionally radiate to the right shoulder, will not be relieved by ingestion of food, and may be exacerbated by the ingestion of fatty food. The commoner forms of liver disease are rarely accompanied by specific abdominal pain, although in most hepatic conditions the liver may be tender and enlarged on examination. A history of jaundice is common with most liver diseases. Jaundice is a syndrome characterised by deposition of yellow bile pigment in the skin, conjunctivae, mucous membranes and urine. Liver disease is significant when the use of amide
local anaesthetics (e.g. prilocaine, mepivacaine, bupivacaine) is being considered. If the liver is damaged and its function impaired by cirrhosis, first-pass metabolism will not operate effectively. First-pass metabolism refers to the removal of drugs from the hepatic portal circulation and their subsequent metabolism in the liver. Certain drugs, for example the opioid antagonist naloxone, are almost completely eliminated by firstpass metabolism. If first-pass metabolism is impeded, an increase in circulating concentrations of the drug will follow. The maximum safe dose that can be administered will have to be reduced in these cases. Chronic alcohol abuse can also increase the activity of the liver's mixed function phase I oxidase enzymes, which are responsible for the metabolism of drugs such as paracetamol, warfarin, barbiturates and benzodiazepines. This increase in enzyme activity and drug metabolism will significantly reduce the therapeutic effect of these drugs. Combined alcohol and drug ingestion, however, will have the immediate effect of enhancing the therapeutic effect of oral hypoglycaemics, benzodiazepines and tricyclic antidepressants, which could produce potentially life-threatening effects. A history of regular nausea, vomiting or dysphagia (difficulty in swallowing) will always demand an explanation. These clinical features may be due to central nervous system problems (e.g. intracranial tumours, meningitis), endocrine disorders (e.g. myxoedema, diabetic ketoacidosis) or systemic or gastrointestinal tract infections. Constipation and diarrhoea are common complaints that are usually benign and self-limiting. Where there is an underlying disease the problem is usually accompanied by fever, severe pain and blood loss. Although not specifically relevant to the lower limb, a history of altered bowel habit is important when making an assessment of the patient's general health and can influence the type of drugs which may be used.
The genitourinary system The kidneys regulate the body's electrolyte and fluid balance. This has implications for lower
THE MEDICAL AND SOCIAL HISTORY 69
---------------
limb circulation and oedema and can delay wound healing. For example, polyuria (excessive urination) is associated with diabetes, cardiac failure or cortisol deficiency, all of which will affect healing. To determine the presence of genitourinary disease the patient should be asked if they:
Jr----i-\---I--
• have any waterworks problems (such as pain) • have their sleep disturbed by the need to go to the toilet • have had any sexually transmitted infections. The practitioner should use the systems enquiry and medical and social history to determine whether the patient is in a high-risk group for blood-borne infections, such as hepatitis B or AIDS. Renal pain is a symptom of gross structural disease of the kidney, such as kidney stones or a blood clot passing down the ureter. Infection or malignancy may also cause pain in the area of the renal angle (Fig. 5.2) as well as more anteriorly in the abdomen. Leg and ankle swelling is an important finding, which may be related to kidney disease and indeed could be the first clinical sign of a renal problem. Renal dysfunction that leads to a massive loss of protein into the urine will disrupt normal capillary haemodynamics, causing reduced transudation of fluid. Fluid will pool in the tissues rather than returning back into the capillary circulation. Oedema of the dependent limb will result, particularly around the ankles. However, it should be remembered Table 5.4
Figure 5.2
RENAL ANGLE
The renal angle.
that renal dysfunction is not the only cause of ankle oedema. Breathlessness on exertion, weight loss, nausea and vomiting also occur in renal failure and may further confuse the clinical picture. A symptom that is renal-specific is disturbed micturition (Table 5.4). Frequency of urination is dependent upon fluid intake and specific drugs within food and drink. Most people urinate 4-6 times every 24 hours, mostly in the daytime.
Causes of abnormal micturition
Abnormality
Definition
Causes
Polyuria
Frequent micturition
Diabetes mellitus, diminution in bladder's effective filling capacity due to infection, foreign bodies, stones or tumour
Dysuria
Painful urination
Irritation and inflammation of bladder or urethra usually due to bacterial infection
Nocturia
Urination during the night
May reflect early renal disease. Decrease in concentrating capacity may be associated with cardiac or hepatic failure
Oliguria
Straining, decrease in force and calibre of urinary stream
Obstruction distal to the bladder. In men most commonly due to prostatic obstruction
Haematuria
Blood in urine
Haematuria without pain: renal or prostatic disease, bladder or kidney tumour. With pain: ureteral stone or bladder infection
70
SYSTEMS EXAMINATION
The patient should be asked if he experiences any pain or problems passing water and whether his sleep is disturbed by the need to pass water. A positive response to these questions requires further investigation as the kidneys may affect bone metabolism as well as blood pressure and water regulation.
Table 5.5 Lower limb signs and symptoms associated with sexually transmitted diseases
Disease
Lower limb signs and symptoms
Reiter's
Asymmetric arthralgia of hip, knee, ankle and metatarsophalangeal joint. 'Sausage toe'. Keratoderma blenhorragica
HIV
Kaposi's sarcoma - a Widespread skin or mucous membrane lesion appearing as a pink or red macule or violaceous plaques and nodules on the face, trunk and limbs. May appear wart-like
Gonococcal arthritis
Acute joint pain, swelling and stiffness. Usually accompanied by urethritis, dysuria and haemorrhagic vesicular skin lesions. Serious joint damage may result if the condition is not properly treated
Sexually transmitted infections
Reiter's disease, gonorrhoea, HIV and syphilis are all sexually transmitted infections (Case history 5.7). Practitioners investigating a lower limb complaint may find it difficult to enquire about sexually related problems (Table 5.5). However, as these conditions can lead to an array of lower limb symptoms, questions about them must be included in the systems enquiry. After enquiring about the urinary system, the patient should be asked if he has ever had any sexually transmitted infections, skin problems or discharge.
The central nervous system Diseases of the nervous system may cause pain in the lower limb, deformity or gait abnormalities. Comprehensive history taking is essential (Case history 5.8). To determine the presence of CNS disease the patient should be asked if they have had: • • • •
any neuromuscular disorder a head injury a stroke epilepsy.
Record details of a family history of epilepsy or neuromuscular disease. General neurological Case history 5.7 A 42-year-old male attended clinic with jaundice. He complained of a fever and malaise, nausea and vomiting. His urine was tested which was found to be dark in colour. He had a 'home' tattoo made by his previous girl friend, who had been an intravenous drug user. Diagnosis: Hepatitis C. This is an inflammation of the liver caused by the hepatitis C virus.
symptoms may be significant. The patient should be asked if he suffers from frequent headaches. While stress-related headaches, migraine and extracranial causes such as cervical spondylosis account for the majority of headaches, cranial arteritis is an important cause in the elderly. Brain tumours (slow onset) and subarachnoid bleeding (sudden onset) must be considered in severe headaches. Fainting, dizziness and visual disturbance may occur in association with headaches. The basis for most fainting episodes is inadequate blood supply to the brain and is commonly cardiac or cerebrovascular in origin. Anaemia, hypoglycaemia and emotional stress can also explain a temporary loss of consciousness.
Case history 5.8 A 40-year-old factory worker presented with bilateral weakness in his legs. A history revealed that the weakness occurred intermittently but was not related to exercise or activity. Four years earlier he has suffered from blurred vision in his right eye and transient bouts of tingling in his right arm. He had not sought a medical opinion for these symptoms for fear of losing his driving licence. The podiatrist suspected a progressive CNS disorder. Diagnosis: Multiple sclerosis. The patient was subsequently referred for a neurological assessment.
THE MEDICAL AND SOCIAL HISTORY
Having recorded disease states of which the patient is aware, enquire further about any peripheral neurological symptoms. Ask the patient if they: • ever get shooting pains in their arms or legs • find their hands or feet go numb • have ever noticed any weakness or sluggishness of the arms or legs. Causes of peripheral neuropathy are summarised in Table 5.6. Numbness and paraesthesia, loss of muscle bulk or weakness are significant findings. If the patient's response is positive, peripheral neuropathy, which can result from a range of causes, should be considered. It is essential to establish the course of the symptoms and consider them in the light of the patient's age. Slow progressive weakness of the limbs over a period of many years in a young person may point to muscular dystrophy, whereas a more acute onset may indicate a demyelinating disorder or spinal cord compression. The significance of some symptoms in the neurological enquiry will be very difficult to interpret because the enquiry relies on the patient's subjective account (Case history 5.8). However, inadequate assessment of the neurological basis Table 5.6
Causes of peripheral neuropathy
Nerve root compression of the sciatic or femoral nerve arising from L4, 5, S1, 2, 3 and T1, 2, L1, 2, 3, 4 respectively Distal nerve compression of the popliteal, common peroneal and anterior tibial nerve Hereditary neurological disease - Charcot-Marie-Tooth disease, Friedreich's ataxia Endocrine - diabetes mellitus, hypothyroidism, hypocalcaemia Chronic alcohol abuse Nutritional disorders - pernicious anaemia, thiamine or vitamin 8 6 deficiencies Renal failure Systemic disorders - rheumatoid arthritis, systemic lupus erythematosus, vasculitis, sarcoidosis, amyloidosis Infections - tuberculosis, AIDS, leprosy, syphilis Tumour - bronchogenic carcinoma, myeloma, lymphoma Toxic agents - carbon monoxide, solvents, industrial poisons, lead Medication - isoniazid, metronidazole, nitrofurantoin
71
Case history 5.9 A 40-year-old male steelworker sought the opinion of a podiatrist when he began to suffer from corns on the dorsal aspect of both fifth proximal interphalangeal joints. The patient reported that his industrial boots no longer fitted properly and joked that he must still be growing as his protective headwear and gloves didn't feel quite right. Further questioning revealed a tendency to sweat profusely even when sitting quietly, regular headaches and joint pains. His wife had remarked that his features had become more rugged. Diagnosis: Acromegaly. A urine sample demonstrated glycosuria and his blood pressure was elevated to 190/110 mmHg.
of foot pathology can lead to inappropriate treatment through missed diagnosis. Neurological assessment of the lower limb is covered in detail in Chapter 7.
The endocrine system Disorders of the endocrine system may be divided into those conditions which present relatively frequently (and are of regular concern) and those which are rare (Case history 5.9). To determine the presence of endocrine disease the patient should be asked if they have had: • sugar diabetes • thyroid problems. In the assessment of the lower limb, diabetes mellitus, thyroid disease, growth disorders, obesity and problems associated with the menopause are particularly relevant. Routine questioning about endocrine symptomatology should begin with asking the patient if they: • ever suffer from a thirst that they find hard to quench no matter how much they drink • have a stable weight. Diabetes is a disease of either insulin deficiency or peripheral resistance to insulin action. Insulin produced by the beta cells of the pancreas decreases blood glucose by inhibiting glycogen breakdown and facilitates the entry of glucose into tissue cells. When peripheral tissues fail to utilise glucose, blood glucose levels rise and glucose is excreted in the urine. Because the body
72
SYSTEMS EXAMINATION
will continue to need a source of energy, homeostasis provokes breakdown of body fat and muscle tissue. This process of 'accelerated starvation' can be quite abrupt in children, causing anorexia, nausea, coma and, if untreated, death. In older patients it is more gradual and indeed the first presenting symptom may be one of the complications of the disease. Thirst, polyuria and weight loss are the three most common symptoms of diabetes. These three features may also occur with other conditions such as diabetes insipidus, hypercalcaemia and renal failure (Table 5.7). The thirst associated with diabetes is a result of the osmotic diuretic effect of glucose - although it is difficult to be precise as to what is excessive thirst. Increased volume and frequency of urination will lead to a corresponding increase in fluid intake. The patient is often aware that sleep is regularly disturbed by the need to urinate and a history of polyuria should always be followed up by glucose testing of the urine. Although diabetics often believe that their decreasing weight is due to polyuria, it is in fact a result of accelerated fat and protein catabolism. The thyroid hormones tri- and tetra-iodothyronine (T3 and T4) are essential for normal growth and development and have many effects on body
Table 5.7
Causes of thirst and polyuria
Cause
Physiological reason
Diabetes mellitus
Osmotic diuretic effect of glucose
Diabetes insipidus
Kidney disease prevents normal concentrating of urine or pituitary gland disorders cause a deficiency of antidiuretic hormone
Hypercalcaemia
Result of hyperparathyroidism where hypercalcaemia causes reversible impairment of renal concentrating mechanism
Hypocalcaemia
Often a side effect of diuretic therapy it leads to impaired concentrating ability in the kidney
Excess salt intake
Osmotic diuretic effect of increased sodium level
Renal failure
Normal concentrating function of kidney lost
metabolism, the most obvious being to stimulate the basal metabolic rate. In thyroid disease there is either inadequate or excessive production of thyroid hormones. The clinical features of hyperthyroidism are listed in Table 5.8. Clinical features of hyperthyroidism such as muscle weakness, tachycardia, weight loss and sleep disturbance may have already been picked up from the systems enquiry. Other features associated with the condition may not have been highlighted, e.g. heat intolerance, hand tremor and irritability. If hyperthyroidism is suspected the patient, should be asked: • Do you find that you cannot tolerate hot rooms or buildings? • Have you noticed a change in your handwlriting? • Do your hands shake? • Do your hands and feet get excessively sweaty? Hyperthyroidism is an important systemic cause of hyperhydrosis of the feet and hands. Other lower limb signs and symptoms include infiltration of non-pitting mucinous ground substance on the anterior surface of the tibia, which causes intense itching and erythema. This socalled pretibial myxoedema (a confusing term since myxoedema suggests hypothyroidism) is more accurately described as an infiltrative dermopathy. Hyperthyroidism can cause tarsal tunnel syndrome and must be considered as a differential diagnosis for this condition, especially as the dermopathy will remain even after thyroid function is stabilised. Table 5.8
Clinical features of hyperthyroidism
Weight loss (with a normal appetite) Heat intolerance Fatigue Cardiac palpitations Irritability Hand tremors Sleep disturbance Bulging eyes Goitre Diarrhoea Generalised muscle weakness
THE MEDICAL AND SOCIAL HISTORY
Inadequate levels of circulating thyroid hormone will lead to hypothyroidism. This condition may be discovered by asking the patient: • Have you noticed any hair loss from your head or eyebrows? • Are you troubled by dry scaly skin on your head or face? • Have you noticed your hands or face getting puffy? • Do you feel you have generally slowed down? • Are you getting forgetful? • Do you notice the cold? • Has your weight increased? In hypothyroidism the facial expression is dull and the features puffy with swelling around the eye sockets due to infiltration of mucopolysaccharides. The eyelids will droop due to decreased adrenergic drive and the skin and hair will be coarse and dry. The tongue may be enlarged, the voice hoarse and speech slow. Tarsal and carpal tunnel syndrome, caused by the infiltration of mucopolysaccharides, are common clinical features. Either form of thyroid disease renders the patient a poor candidate for foot surgery because it reduces his ability to deal with stress. Cardiac arrhythmias or metabolic imbalance may occur in stressful situations. Screening for thyroid disease is therefore essential and the above enquiry should be included in any presurgery assessment. Disorders of the adrenal gland should also be considered. The adrenal gland has two functionally distinct parts, the cortex and the medulla. The more important of the two, the adrenal cortex, is essential for life as it produces glucocorticoids and mineralocorticoids, which are essential for maintaining blood volume during stress. The patient should be asked: • Do you ever feel faint or dizzy when standing up after sitting for some time? • Have you noticed any coloured patches or streaks developing on your skin? • Have you had any problems with increased facial hair? • Do you bruise easily?
73
The adrenal cortex is susceptible to either hypo- or hyperfunction. Hypofunction or Addison's disease is an autoimmune condition; the majority of clinical features are due to deficiency in glucocorticoid and mineralocorticoid (Table 5.9). The most relevant aspect of Addison's disease is the reduction in the level of cortisol. This hormone is normally produced in response to stress. Cortisol deficiency will reduce resistance to infection and trauma. Cushing's syndrome presents as an overproduction of glucocorticoids. High levels of cortisol increase carbohydrate production and lead to truncal obesity and development of a moon face. Purple striae or stretch marks will develop on the abdomen. An increased production of androgens may cause hirsutism. Thinning of the skin and increased risk of infection are important lower limb features of Cushing's disease. Osteoporosis may occur as a sequel to disruption of normal kidney function. Secondary diabetes mellitus may also occur as a sequel to Cushing's disease.
Table 5.9 Clinical features associated with disorders of the adrenal glands
Disorder
Clinical features
Adrenal undersecretion (e.g. Addison's disease)
Common features: Tiredness Generalised weakness Lethargy Anorexia Weight loss Dizziness and postural hypotension Pigmentation
Adrenal oversecretion (Cushing's syndrome)
Less common features: Hypoglycaemia Loss of body hair Depression Truncal obesity (moon face, buffalo hump, protuberant abdomen) Thinning of skin Purple striae Excessive bruising Hirsutism Hypertension Glucose intolerance Muscle weakness and wasting, especially of proximal muscles Back pain (osteoporosis and vertebral collapse) Psychiatric disturbances
74
SYSTEMS EXAMINATION
Overactivity of the anterior pituitary gland will increase circulating levels of growth hormone, which results in excessive growth of feet, hands, jaw and soft tissue acromegaly. Excess growth hormone leads to glycogenesis: approximately 30% of acromegalies develop diabetes mellitus. Hypertension, due to inadequate renal clearance of phosphates, affects 30% of acromegalies. The majority of acromegalies suffer from constant headaches and joint pains. The condition, although rare, has significant foot health implications with a catalogue of signs and symptoms that will become apparent during virtually every stage of the functional enquiry.
The locomotor system To determine the presence of musculoskeletal disease the patient should be asked if they have ever had: • • • • • •
any form of arthritis back, hip, knee, ankle or foot pain fractures of any bones in the legs or feet pulled or injured muscles in the legs joint swelling or stiffness limb pain during any specific activity.
The patient's account of spine or lower limb pain involving areas other than that of the presenting complaint should be obtained. The aim of the locomotor enquiry is to broaden the practitioner's outlook beyond the specific presenting complaint to a broader view of the locomotor system. Information from the locomotor enquiry will help to exclude conditions which may have
Case history 5.10 A 45-year-old female teacher presented with pain under the balls of both feet. She complained of general malaise and would go to bed much earlier in the evening than she used to. She described stiffness in her hands and knees, which was worse in the morning but improved after a hot bath and an aspirin. On examination the small joints of her hands and feet were swollen, leading the practitioner to suspect a systemic rather than local mechanical cause. Diagnosis: Rheumatoid arthritis. This was confirmed by a blood test, which showed a raised ESR (erylthrocyte sedimentation rate) and rheumatoid factor.
a systemic origin (Case history 5.10). Assessment of the locomotor system is considered in detail in Chapter 8.
SUMMARY Accurate diagnosis, which starts with taking the patient's medical and social history, forms the basis for formulation of an effective treatment plan. A format for history taking has been presented which covers all aspects of the patient's current and past medical status (Fig. 5.3). It has been emphasised that the personal social history is as important as the medical history, since it enables an assessment to be made about aspects of the patient's lifestyle which could influence any proposed treatment. The approach outlined in this chapter will ensure that a broad range of factors are taken into consideration when making a diagnosis and drawing up a treatment plan.
THE MEDICAL AND SOCIAL HISTORY
75
Current health status: Not sleeping well, appetite poor, 'nerves bad'.
Current and past medication: Presently taking temazepam as required. Co-proxamol for foot pain. Uses purgatives once weekly. In past prescribed hormone replacement therapy, caused intolerable nausea and hot flushes. Also used amytal barbiturates for 2-year period. Current family doctor refused repeat prescription. Smokes 20 per day, drinks rarely.
Past medical history: 'Nervous breakdown' 10 years ago after menopause. Bronchitis almost every winter requires antibiotics. Hospitalisations, operations, injuries: Fell and broke wrist 2 years ago, required a plate subsequently removed. Patient now discharged from orthopaedic department.
Family history:
l<-e-5u.lcJ ~0 ~
anr.kv
Figure 5.3
Specimen medical and social history and functional enquiry.
Personal social history: Now retired previously factory operative - sedentary. Lives with husband who appears to be a regular and heavy drinker. Owns terraced house. Uses public transport. No foreign travel. Daughter lives in London never visits. All friends have moved away few visitors.
Systems enquiry: Cardiovascular. Chest pain only with bronchitis. Shortness of breath when walking fast or uphill. Ankles swell every day, feet always cold. No calf pain on walking. Respiratory: Every morning productive cough, relieved by first cigarette. Occasionally blood-stained sputum. Gastrointestinal: Still has lower teeth, top teeth all removed 1958. Regular indigestion, especially after vinegar or spicy food. Uses laxative to ease constipation. Genitourinary: No dysuria, infections or discharge. Central nervous system: No headache, no paraesthesia, vision fine, no fits or faints. Locomotor system: Right hip painful ?arthritic. Painful bunions causing shoe-fitting problems. Endocrine: No symptoms reported. Summary: Depressed, lonely 68-year-old, generally run down though no specific health problems at present. In winter troubled by bronchitis probably related to heavy smoking.
76
SYSTEMS EXAMINATION
FURTHER READING British National Formulary (BNF), updated twice yearly. British Medical Association (BMA) and Royal Pharmaceutical Society of Great Britain (RPSGB), London Greenberger N, Hinthorn D 1993 History taking and physical examination; essentials and clinical correlates. Mosby Year Book, St Louis Munro J F, Campbell I W 2000 Mcl.eod's clinical examination, LOth edn. Harcourt Brace, Edinburgh Seidel H M et al1995 Guide to physical examination, 3rd edn. Mosby, St Louis
Seymour p, Siklos C 1994 Clinical clerking: a short introduction to clinical skills, 2nd edn. Press Syndicate of the University of Cambridge Tally N, O'Connor S 1989 Clinical examination. Blackwell Scientific, Oxford Turner R, Blackwood R 1991 Lecture notes on history taking and examination, 2nd edn. Blackwell Science, Oxford Zier B 1990 Essential of internal medicine in clinical podiatry. W B Saunders, Philadelphia
CHAPTER CONTENTS Introduction
79
Vascular assessment
THE PURPOSE OF A VASCULAR ASSESSMENT 79
J. McLeod Roberts
OVERVIEW OF THE CARDIOVASCULAR SYSTEM 80 Anatomy of the cardiovascular system The heart 80 Peripheral circulation 81
80
Normal physiology of the cardiovascular system 85 THE VASCULAR ASSESSMENT
89
General overview of the cardiovascular system 89 Past history and current medication 89 Symptoms 90 Observable signs 91 Clinical tests 92 Hospital tests 94 Peripheral vascular system Arterial insufficiency Medical history 95 Symptoms 96 Observation 97 Clinical tests 98 Hospital tests 105
95
95
Venous drainage 106 Past history 107 Symptoms 107 Observation 107 Clinical tests 109 Hospital tests 109 Lymphatic drainage 110 Medical history and symptoms Observation 110 Clinical tests 111 Hospital tests 111 Summary
111
110
INTRODUCTION Assessment of the patient's vascular status is an essential part of the primary patient assessment. Davies & Horrocks (1992) noted that there has been an increase in the number of patients presenting with vascular disease. This chapter begins by explaining the purpose of a vascular assessment and then proceeds to provide an overview of the anatomy and physiology of the cardiovascular system. It continues by describing the necessary steps to be taken when assessing the cardiovascular and in particular the peripheral vascular status of the patient. Ranges of expected and abnormal values are included where appropriate. Simple, non-invasive tests are described which can be carried out by the practitioner using the minimum of equipment; hospital-based tests are also briefly described.
THE PURPOSE OF A VASCULAR ASSESSMENT The vascular status of the lower limb bears a direct relationship to tissue viability; furthermore, the severity of vascular disease has been shown to be associated with an increase in morbidity and mortality (Howell et al1989). It will be apparent from this that assessment of the vascular status performs a useful screening function by detecting previously unidentified vascular abnormalities. 79
80
SYSTEMS EXAMINATION
Information gained from a vascular assessment can be used to achieve the following: • Identify whether the blood supply to and from the lower limb is adequate for normal function and tissue vitality. • Identify vascular problems which could compromise the state of the tissues. It is important to detect not only the presence of such abnormalities but also the functional site, e.g. is it an arterial or venous insufficiency or a combination of both? These patients require monitoring so that complications - e.g. necrosis, ulceration and infection - can be prevented or their effects reduced. • Identify whether there are any vascular abnormalities which could affect healing or the choice of treatment. These should be borne in mind when drawing up a treatment plan.
• Identify those patients in whom vascular conditions require further investigation by referral to a specialist.
OVERVIEW OF THE CARDIOVASCULAR SYSTEM ANATOMY OF THE CARDIOVASCULAR SYSTEM The cardiovascular system (CVS) consists of a closed system of vessels through which blood and lymph are pumped around the body by means of the heart (Fig. 6.1).
The heart The heart is constructed as a double pump in series: one pump comprising the left side of the
carotid artery
superior vena cava
dorsal aorta inferior vena cava hepatic vein
hepatic portal vein
hepatic artery
mesenteric artery
RA = right atrium RV = right ventricle LA = left atrium LV = left ventricle
Figure 6.1 The major vessels of the cardiovascular system. In the body proper, the dorsal aorta and the vena cavae run in the central axis, but for purposes of clarity they are shown to the right and left of the body, respectively. RA = right atrium, RV = right ventricle, LA = left atrium, LV = left ventricle, GIT = gastrointestinal tract.
VASCULAR ASSESSMENT
heart and the other the right side (Fig. 6.2). Each pump has two chambers. Each upper chamber or atrium is a receiving vessel with a thin muscle wall or myocardium, whereas the lower chambers or ventricles are the dispersing vessels and therefore have much thicker muscle walls to generate strong propulsive forces (Fig. 6.3). The heart is lined by endocardium and surrounded by a tough, non-extensible pericardium. The endocardium forms the cusps of one-way valves, called the tricuspid and bicuspid valves, which control the flow of blood through the heart. It also forms semilunar valves, which control the entry of blood into the vessels leaving the heart. Closure of these valves is responsible for the two heart sounds, 'Iub-dup', which can be heard through a stethoscope applied to the chest wall. The heart serves two circulations. The right ventricle serves the pulmonary or minor circulation and sends deoxygenated blood via the pulmonary arteries to the lungs, whereas the left ventricle supplies the systemic or major circulation with oxygenated blood through the aorta to the body (Fig. 6.2). Oxygenated blood is returned from the lungs via the right and left pulmonary veins into the left atrium and deoxygenated
81
blood from the body flows through the superior and inferior vena cavae into the right atrium.
Peripheral circulation The blood flows through the two circulations via a system of vessels of varying diameters (Table 6.1). Arterial tree
The vessels which transport blood to the tissues are called arteries. These branch into consecutively smaller vessels called arterioles. The walls of arteries consist of three layers - the tunica intima, tunica media and tunica adventitia - all of which are lined with vascular endothelium, whose cells secrete a variety of substances essential for maintenance of vessel wall and circulatory function (Fig. 6.4A). All the vessels have some smooth muscle in the tunica media to enable them to change diameter, but arterioles have the greater proportion. The arteries leaving the heart have a high proportion of elastic tissue in their walls, which enables them to act as secondary pumps, whereas the rest of the arterial tree consists of muscular distributing vessels. The smallest arterioles deliver blood to capillary beds. Venous tree
Blood is drained from the tissue beds by small vessels called venules, which join to form larger vessels called veins. The three layers seen in the arterial walls are again present but the proportions differ, as can be seen in Figure 6.4A. The vascular endothelium forms semilunar valves in the veins and venules to prevent backflow of
Table 6.1
Figure 6.2 The heart is a double pump in series. It serves two circulations, the low-pressure pulmonary and the highpressure systemic circulation.
The anatomy of peripheral vessels
Vessel
Diameter
Wall thickness
Aorta Artery Arteriole Capillary Venule Vein Vena cava
25 cm
2 mm 1 mm 20 urn 1 urn 2 urn 500 urn 1.5mm
4 30 6 20 5 30
mm
urn
urn urn mm mm
82 SYSTEMS EXAMINATION
Aorta
Superior vena cava
Pulmonary artery
Right pulmonary vein \ - - - - - - Left pulmonary vein
~--------- Left atrium Right atrium - - - - - f
"'*"'i
Chorda tendinae
l+\?c-"t\----
Left ventricle
."lll!rllJrt---- Thick-walled
myocardium Inferior vena cava
Right ventricle Endocardium Figure 6.3 Vertical section through the heart showing the valves, chorda tendinae, main vessels attached and the varying thickness of the myocardium. The direction of flow of oxygenated (non-shaded arrows) and deoxygenated (shaded arrows) blood is also shown.
blood. Veins are found either in the superficial fascia or deep in the muscle. Communicating veins link the two types so that blood can drain from the superficial veins to the deep ones. Capillary
A third type of vessel, the capillary, links arterioles and venules. This is the smallest and most
numerous vessel, having only a thin-walled endothelium (Fig. 6.4B). It permeates all the tissue beds so that no tissue cell is far from a capillary. Flow of blood into individual capillaries is regulated by smooth muscle sphincters in vessels called metarterioles, which are situated at the entrances to the capillaries. Capillaries can be bypassed by arteriovenous (A-V) anastomoses: these are vessels which form a direct link
VASCULAR ASSESSMENT
A
Tunica adventitia Tunica media Tunica intima '------- Lumen ------' ' - - - - - Endothelium-------' Artery Vein
B
83
between an arteriole and a venule (Fig. 6.5A). In peripheral cutaneous sites exposed to extremes of temperature, such as the skin of fingertips, apices of toes, nose and earlobes, the A-V anastomoses are very numerous and form specialised structures under the nail beds called glomus bodies or Sucquet-Hoyer canals (Fig. 6.5B).
Endothelium
Basement membrane
A. --u--
Microcirculation Lumen
The smaller-diameter vessels collectively form the microcirculation.
Capillary Figure 6.4 A. Cross-section through an artery and vein showing tunica intima, media and adventitia B. Crosssection through a capillary. Note the relative proportions of thickness in artery and vein and its absence in the capillary.
Collaterals
Most microcirculations are served by more than one branch of the arterial tree. These parallel
-tI-+F""----
AVA
Metarteriole
A Modified muscle cells
Arteriole B
Figure 6.5 A. Diagram of the microcirculation showing an arteriole and a venule connected by an arteriovenous anastomosis (AVA) and a capillary network. The AVA is a shorter, tortuous, muscular vessel of a larger calibre. The capillary network comprises metarterioles, which have a muscular coat, and the distal portion of the capillary network, which consists solely of endothelial cells B. Diagram showing the specialised AVA under the nail bed (glomus body).
84
SYSTEMS EXAMINATION
branches are called collaterals and may anastomose freely or hardly at all, the degree of communication varying from tissue to tissue (Fig. 6.6A). The lack of anastomoses in the coronary circulation is responsible for the dramatic effects of an occlusion in the left coronary artery (Fig. 6.6B).
Lymphatic tree
Lymphatic vessels are very similar in structure to veins and capillaries, except that the smallest vessels are blind-ended (Fig. 6.7). They drain the tissues and transport lymph through various lymph nodes, eventually rejoining the peripheral circulation through the thoracic duct.
A
Aorta---f"--. ~A--------
"*--:.;;,~-----
Pulmonary artery Left coronary artery
Right coronary artery ---/+';b-"--------,ti >\:i\k--
Circumflex branch
B Figure 6.6 A. Small side vessels normally carry an insignificant fraction of blood into the peripheral tissues. Damage or occlusion of the major arteries alters pressure relationships to divert blood through the side vessels (collateral circulation). B. Anterior view of heart showing lack of anastomoses between arterial vessels supplying the myocardium. Left coronary artery supplies hatched area, right coronary artery supplies unhatched area. The lack of anastomoses between left and right coronary arteries explains why an occlusion of the left coronary artery can be so catastrophic.
VASCULAR ASSESSMENT
-f-----
85
Lymphatic venule with valves
Blind-ended lymphatic capillary
Figure 6.7
Diagram showing a blind-ended lymphatic capillary.
Tissue fluid
While capillaries bring blood close to all body cells, a diffusion medium is needed to enable nutrients, waste products and gases to be exchanged between the cells and the blood and lymph. This medium is tissue fluid, which is continuously forming from blood at capillary and postcapillary venular sites as a result of hydrostatic and oncotic pressures (Fig. 6.8). Some tissue fluid is reabsorbed back into these vessels, the remainder draining into the lymphatic capillaries to be returned to the general circulation.
NORMAL PHYSIOLOGY OF THE CARDIOVASCULAR SYSTEM The essential function of the CVS is to ensure that there is sufficient perfusion pressure to maintain, under all circumstances, an adequate flow of blood to the vital organs, especially the brain. This is achieved by alteration of the rate and force of contraction of the myocardium and by varying the diameter throughout the peripheral circulation. In periods of increased demand, nonvital areas will have a reduced flow and this may very well affect the lower limb.
The heart contracts about once every 0.8 seconds in a healthy resting adult. The heart beat is divided into two phases: the relaxation phase or diastole and the contraction phase or systole. Systole is the shorter of the two phases, lasting about 0.3 seconds, though with increased heart rate, the period of diastole shortens. The volume of blood ejected from each ventricle is the same and is called the stroke volume. In a healthy resting adult about 70 ml is ejected at each contraction of the ventricle. Since the normal resting heart rate is an average of 72 beats per minute, the volume ejected from each ventricle in 1 minute is approximately 5 litres and is known as the cardiac output. The myocardium has the ability to contract without nerve impulses. This property is called myogenicity and is due to the presence of specialised 'pacemaker' cells which generate spontaneous action potentials. The most important of these is the sinoatrial (SA) node, situated in the right atrium (Fig. 6.9). The action potential spreads rapidly through the other specialised conducting tissues and then out over the rest of the myocardium through gap junctions between the cells. This ensures that the cells can respond as a unit, producing a coordinated
86
SYSTEMS EXAMINATION
wave of contraction which pushes the blood in the desired direction. Apart from these specialised pathways, the septa that divide the four chambers of the heart consist of fibrous, non-conducting tissue. While the heart can contract without nervous stimulation, it is essential that it can alter its activity according to the differing demands placed upon it as mentioned earlier. One way
that this is achieved is via the autonomic system (ANS) (Ch. 7). The two branches of the ANS send fibres to the SA node. The sympathetic nerve acts on the heart via specific receptors called beta 1receptors, the action of which is to increase cardiac output by increasing both stroke volume (positive inotropy) and heart rate (positive chronotropy). The parasympathetic nerve to the heart is called the vagus and causes slowing of
Arterial end
respiring cells
HPb high OcPb high blood (protein .salts, water, cells)
water, salts and small amount proteins
HPb low OcPb high
Venous end
Blood
Tissue fluid
< HPt
> HPt
HPb OcPb
> OcPt
Fluid in (small)
Net pressure forces fluid out
OcPt
Result Fluid in Fluid in
Net pressure forces fluid in
HPb(t) = hydrostatic pressure of blood (and pressure flow) OcPb(t) = oncolic pressure of blood (b) and tissue fluid (t) oncolic pressure = oncolic pressure due to protein Figure 6.8 The process of formation and reabsorption of tissue fluid in an ideal capillary. Movement of fluid in and out of the capillary will vary according to the precise balance of pressures along the capillary at anyone time.
VASCULAR ASSESSMENT
the heart rate (negative chronotropy), acting through cholinergic receptors. At rest the parasympathetic nerve predominates, producing the average resting heart rate of 72 beats per minute. The rate is less in trained athletes and higher in children and is also affected by posture, increasing on a change from a supine to an upright position by approximately 10 beats per minute. The latter is due to compensation for the effects of gravity on blood in the peripheral vessels and is mediated through the baroreceptor reflex (Fig. 6.10). Baroreceptors are situated in both the arterial and venous components of the systemic circulation, but the arterial baroreceptors in the aortic arch and carotid body are the more important for regulation of blood pressure. They continuously monitor the level and feed this information to the cardiovascular control centre in the part of the brain stem called the medulla oblongata. As a result of this information being integrated in the medulla, compensatory adjustments are made to the action of the heart and the diameter of the arterial tree through
the sympathetic nerves, which act on the smooth muscle of the tunica media. Despite being very sensitive to changes in blood pressure, baroreceptors show a rapid adaptation to a sustained change, so that in hypertension they are triggered by a higher than normal 'operating' range. All vessels except capillaries are subject to some sympathetic influence or 'tone'. The greater the sympathetic tone, the more vasoconstriction is achieved, with vasodilation being produced by a reduction in this tone. This in turn produces a change in resistance to flow, or peripheral resistance, a change in the pressure exerted on the blood and a change in the work the heart has to do (afterload), The greatest effect is produced in the arterioles, called the resistance vessels, which as mentioned previously have the largest proportion of smooth muscle in their walls. They allow the CVS to control distribution of blood and, together with the heart, are the effector organs for the homeostatic control of blood pressure. A similar reflex exists to regulate blood volume, which in addition involves, to a greater extent,
Atrial excitation begins
Ventricular excitation complete
A
87
begins
B
Right and left branch bundles
complete
Purkinje fibres
C
o
Figure 6.9 Vertical outline of the heart, showing the SA node (A), AV node (8), bundle of His (C), Purkinje fibres (D) and spread of waves from the SA node (A-D).
88
SYSTEMS EXAMINATION
the low-pressure baroreceptors in the right atrium and where the effector organs include the kidney as well as the CVS. The aorta and pulmonary arteries are the elastic arteries, having a large proportion of elastic tissue in their walls. This distends as the bolus of blood is received from the ventricles and acts as a secondary pump during diastole when the elastic recoil propels the blood forward. The rebound causes a shock wave to travel rapidly through the blood in the arterial tree and it can be felt as a pulse wave at certain points called pressure points. The overall purpose then of all the vessels within the systemic circulation, with the exception of the capillaries, is to deliver blood with its dissolved nutrients, oxygen and hormones to the tissues and to remove metabolic waste such as carbon dioxide and urea. This transportation must meet the demands of the different tissues, which will vary in need according to their nature and level of activity. Heat is also distributed from areas such as active muscles and the liver to the rest of the body. The skin is an important organ for controlling heat loss, involving the
t
ARTERIAL PRESSURE
Arterial baroreceptors tFIRING
Reflex via medullary cardiovascular centre
... SYMPATHETIC OUTFLOW TO HEART, ARTERIOLES, VEINS
Figure 6.10 Flow chart showing the arterial baroreceptor reflex. If arterial pressure decreases the arrows in the boxes would be reversed.
superficial papillary loops and the specialised glomus bodies which can re-route blood towards or away from the skin surface. The purpose of such redirection is either to control heat loss or to ensure that superficial tissues do not suffer from ischaemia caused by coldinduced vasoconstriction. The function of the capillaries is the exchange of the substances transported to the tissues by the blood. It is here that tissue fluid plays its essential role of intermediary between blood and tissues mentioned earlier, being the ideal candidate since it bathes every cell. There is a large pressure drop across the capillary beds so that blood flowing in the venules and veins is at low pressure and needs help to get back to the heart, in the form of semilunar valves, venoconstriction and the pumping action of surrounding skeletal muscle on the deep veins. In addition, the fluctuating negative pressures in the abdomen and thorax, due to respiratory movements and the action of the heart itself, all act as suction pumps, drawing blood back into the atrial chambers. The volume of blood returning to the heart is termed the venous return or preload. It is essential that ventricular output exactly matches this venous return to avoid a transfer of blood from one circulation to the other. This matching of venous return and cardiac output is an intrinsic property of the myocardium, independent of nervous control, which is often referred to as Starling's law of the heart. The consequences of unmatched venous return to cardiac output is seen in a person with congestive heart failure, the congestion being due to a build up of blood throughout the venous tree because of a weak or damaged myocardium. In addition to returning blood to the heart, veins, because of their distensibility, act as capacitance vessels, normally holding three-fifths of the total volume of blood in the body. This can boost the circulation when necessary. The purpose of the pulmonary circulation is to deliver blood containing carbon dioxide to the lungs and exchange it via the alveolar capillaries for oxygen. Having two separate circulations also allows each to operate at a different pressure.
VASCULAR ASSESSMENT
Red blood cells contain the pigment haemoglobin, which picks up oxygen in the lungs in a stepwise manner and releases it in the tissues. Presence or absence of oxygen causes a change in shape of the haemoglobin molecule and with it a change in colour, so that oxygenated blood is bright red and deoxygenated blood is bluish-red. Red blood cells or erythrocytes are formed from stem cells in the red bone marrow and mature under the influence of kidney hormones or erythropoietins. Various factors are needed, such as iron, folic acid and vitamin BI 2 , for formation of the mature erythrocyte. The red blood cell circulates for 120 days before being broken down in the liver by phagocytic von Kupffer cells. Anaemias, reduction in the oxygen-carrying capacity of blood, can result from a defect in any part of this process. For example, damage to the bone marrow by radiation can damage the stem cells or the young red blood cells, resulting in aplastic anaemia. An autoimmune disease can destroy the parietal cells in the stomach, leading to lack of Castle's intrinsic factor, and this causes an inability to absorb vitamin BI 2 , which is required for erythropoiesis and normal nerve function. After some delay, pernicious anaemia develops.
THE VASCULAR ASSESSMENT An assessment of the vascular status of a patient consists of a general overview of the cardiovascular system and a detailed assessment of the peripheral vascular system, with particular reference to the lower limb. As mentioned previously, the peripheral vascular system consists of arteries, veins and lymphatics. The assessment of each part of the vascular tree involves: past history and current medication symptoms observable signs clinical tests hospital tests. Accurate diagnosis can often be achieved by simple observation. Research which compared • • • • •
89
diagnoses made by practitioners using observation with diagnoses arrived at with the aid of hospital tests found that the former method was almost as reliable as the latter.
GENERAL OVERVIEW OF THE CARDIOVASCULAR SYSTEM Central problems such as congestive heart failure, angina of effort and myocardial infarction as well as systemic problems such as the anaemias can all have a bearing on the diagnosis and management of lower limb problems and so must be taken into consideration (Table 6.2), although full investigation of such problems are beyond the scope of this textbook.
Past history and current medication History taking is discussed in detail in Chapter 5. Any factors which reduce or prevent tissue perfusion will not only deprive the tissue of oxygen but also of nutrients, and prevent removal of waste products, causing a condition referred to as ischaemia. The most common cause of ischaemic heart disease (IHD) is atherosclerosis of coronary vessels; therefore, IHD is often termed coronary arterial disease (CAD). The presence of CAD should alert the clinician to possible atherosclerosis in the lower limb. The
Table 6.2 perfusion
Cardiac conditions which may affect lower limb
Heart failure: left- and/or right-sided Ischaemic heart disease: angina or myocardial infarction Rheumatic fever Myocarditis Valve disorders: mitral stenosis aortic stenosis mitral regurgitation tricuspid regurgitation Infective endocarditis Congenital heart disease: septal defects valve defects coarction of the aorta Fallol's tetralogy
90
SYSTEMS EXAMINATION
Case history 6.1 A male Caucasian first presented to the clinic when 74 years old, complaining of hard skin on the balls of his feet and on the ends of his toes. He was finding it difficult to focus and so had sought treatment. His medical and social history revealed that he was a smoker and that he had had an aortic aneurysm resected when aged 73. He was taking bendroflumethiazide (bendrofluazide). A preliminary vascular assessment showed telangiectases and haemosiderosis superimposed on a normal skin colour in both lower limbs. Varicose veins were present in the right leg, hair was absent from legs and feet and the skin was dry. Nails were long but otherwise unremarkable. The feet felt cold. All four pulses were palpable and demonstrated arrhythmia. Brachial BP was 110/60 mmHg. The patient failed to attend further appointments until 3 years later, when examination revealed cyanotic feet with the right foot being worse than the left. His toenails were thickened and crumbly and oedema was present in both ankles. Pedal pulses were barely palpable.
medical history should reveal conditions which indicate coronary artery disease, such as angina of effort or previous myocardial infarctions. The presence of risk factors for atherosclerosis should also be noted, such as smoking or the presence of diabetes mellitus, hypertension or hyperlipidaemia (Case history 6.1). Anti-hypertensive medicaments such as diuretics, beta-blockers, ACE inhibitors and calcium antagonists all indicate a vascular problem which often has a central component. Diuretics act on various parts of the kidney nephron to reduce water and salt reabsorption, reducing preload and cardiac output and, as a consequence, blood pressure. Beta-blockers prevent the stimulatory action of endogenous catecholamines on the heart, again reducing cardiac output and blood pressure. ACE (angiotensin-converting enzyme) inhibitors interfere with the production of angiotensin 2, which is both a powerful vasoconstrictor and triggers release of the hormone aldosterone from the adrenal cortex. As aldosterone promotes water and salt reabsorption from the kidney, drugs that inhibit its release will again reduce preload and cardiac output, so that ACE inhibitors promote a two-pronged attack on blood pressure. Calcium antagonists act by interfering with the process of vascular smooth
Transcutaneous oxygen tension (Tcp02) values of right and left dorsum of the feet were 41 and 47 mmHg, respectively. He had suffered a myocardial infarction and a stroke when 76 and his medication had been changed to digoxin and furosemide (frusemide). When the patient first presented to the clinic, the condition of skin, nails and general tissue viability were unremarkable for someone of his age. Three years later he had suffered a myocardial infarction and a stroke, which suggests possible atherosclerosis in coronary and cerebral arteries. The likelihood of lower limb arteries also being involved is considerable and would account for the low oxygen tension in the skin and the barely palpable pedal pulses. Smoking is a risk factor for atherosclerosis and for strokes. The peripheral oedema and cyanosis were likely to be consequences of cardiac insufficiency following the myocardial infarction, although asymmetry also suggests some peripheral factors at play, i.e, venous incompetency.
muscle contraction, reducing peripheral resistance and so reducing blood pressure.
Symptoms Angina and myocardial infarction
Pain in the chest on exercise or other stress indicates inadequate blood supply to the myocardium. Angina may occur as the result of a previous myocardial infarction (M!) or may be the precursor to an MI. The pain of angina can vary from a mild discomfort to an intense crushing sensation, or a feeling as if the chest is being gripped by a steel band. It may radiate into the left arm, to the back and the throat or even down the right arm. It may settle into a predictable pattern so that the patient will be able to describe the trigger factors and the intensity, duration and frequency of the attacks. More seriously, the attacks may increase in frequency or intensity, when it is termed unstable angina and may be prodromal to an acute heart attack. Unless vigorously treated, a large proportion of patients with unstable angina will go on to develop MI within weeks (Kumar & Clark 1990a). It is important to recognise such situations should they develop, as prompt action is essential.
VASCULAR ASSESSMENT
The chief distinguishing feature of an acute MI as opposed to an angina pectoris attack is that the latter lasts only minutes and is usually relieved within 5 minutes by rest or by sublingual nitroglycerine. Any chest pain that does not ameliorate after both these procedures must be viewed with concern. If after administration of further nitroglycerine the patient still does not obtain relief, emergency services should be called. There are many other causes of chest pain: few closely mimic angina, although indigestion and other gastrointestinal disorders are often confused with angina (Ch. 5). Breathlessness (dyspnoea)
While the most common cause of dyspnoea is physical exertion, it can be associated with cardiac problems. It should be established whether the patient is a smoker or not, since there is a close correlation between smoking and cardiovascular problems. The early stages of heart failure result in metabolic acidosis, which causes compensatory hyperventilation. In ~ater stages, the lungs are congested and ventilatory effort is increased. Difficulty in breathing when supine (orthopnoea) accompanies left ventricular failure (Kumar & Clark 1990b).
Lassitude
One of the main symptoms associated with anaemia is lassitude, with other symptoms depending on the severity and duration of the condition and the particular type of anaemia such as peripheral neuropathy associated with pernicious anaemia or leg ulcers associated with sickle cell anaemia. Although anaemias lead to hypoxia in the tissues, their effects on tissue viability tend to be less severe than those of arterial occlusion since they have no direct effect on supply of nutrients and removal of waste products. However, Blackwell (2001) states 'even mild cases of anemia warrant investigation. Whatever it's cause, ... anemia can signal a life-threatening condition'. In the elderly, anaemia can trigger or exacerbate angina pectoris, claudication or dementia.
91
Observable signs Oedema
Any factor which interferes with the normal process of tissue fluid formation and reabsorption may cause fluid to accumulate in the tissues. This is referred to as oedema, which will be observable in the peripheral tissues as swelling. It can be due to local factors, such as trauma or occluded drainage vessels, or to central factors such as congestive heart failure, where the failure of the left ventricle to produce an adequate cardiac output causes backward pressure through the CVS, in time causing right ventricular failure. Just as left ventricular failure produces oedema in the pulmonary circulation, right ventricular failure results in bilateral peripheral oedema, especially noticeable in the lower limbs (Case history 6.1). An important exacerbating factor is the reninangiotensin-aldosterone system, which is triggered by the low cardiac output and causes renal retention of salt and water, thus imposing an even greater load on the failing heart. Cyanosis
Central cyanosis is the bluish discoloration of lips, tongue and mucous membranes and indicates that arterial blood is inadequately oxygenated. It may be due either to deficiencies in the pump such as a congenital hole in the heart, cardiac failure, or to deficiencies in ventilation such as chronic obstructive airways disease. Severe cardiac and respiratory failure will also cause peripheral cyanosis of toes and feet. Pallor
A generalised pallor, especially noticeable in the face, may indicate anaemia. Spoon-shaped nails (koilonychia)
Lack of iron results in iron-deficiency anaemia, which causes koilonychia of the finger nails and a smooth, red tongue.
92
SYSTEMS EXAMINATION
Clubbing of the nails (hippocratic nails)
Clubbing of the finger nails may be due to subacute infective endocarditis or congenital cyanotic heart disease. It is also associated with a variety of other, primarily respiratory, causes, e.g. bronchial carcinoma. Splinter haemorrhages
These usually appear near the nail margins and are associated with vasculitis (inflammation of small vessels). They may have a local cause such as a digital septic thrombus, or may herald a widespread involvement of arteries of all organs, including coronary, splanchnic and cerebral, as may be seen in severe rheumatoid arthritis. Splinter haemorrhages may also indicate subacute bacterial endocarditis.
Clinical tests Heart rate
This is normally assessed by taking the pulse at the wrist. Arrhythmias are abnormal heart rates and can be physiological or pathological, depending on the cause. Heart rates of less than 60 beats per minute are classified as bradycardia and those over 100 beats per minute as tachycardia. An example of a physiological bradycardia is that seen in trained athletes, whereas the bradycardia due to a complete heart block in the atrioventricular septum is pathological. Physiological arrhythmia may also be associated with respiration and is called sinus arrhythmia, appearing as a tachycardia on inspiration and a bradycardia on expiration. It is more noticeable in young people and is thought to be due to fluctuations in the parasympathetic output to the heart (Ganong 1991), although the fluctuations in thoracic negative pressure may exacerbate the effect through the operation of Starling's law of the heart. Beta.eblockers such as atenolol will induce a bradycardia and thus reduce cardiac output and blood pressure. Such drugs are therefore given as antihypertensives. In contrast, thyroid hormones, if present in excess, increase the affinity of betaI-receptors to catecholamines and so induce
tachycardia, as seen in hyperthyroidism. The tachycardia of exercise illustrates the relationship between heart rate and efficiency, since with up to approximately 180 beats per minute cardiac output also rises; however, at rates greater than this, the diastolic period is so short that the heart cannot fill properly and cardiac output falls. The quality of the pulse should also be noted. Is it irregular, bounding or feeble? The pulse can be graded on a score of 0-4, with 0 representing no pulse and 4 representing a bounding, strong pulse. Irregular or abnormal pulses (arrhythmias) may be physiological (e.g. due to exertion, anxiety, training or age) or may be due to some underlying systemic condition such as thyroid disorders or medication such as beta-blockers. Similarly, a bounding pulse can be due to response to stress, a sign of pyrexia, or can be seen in pathological conditions such as thyrotoxicosis, or in a hypoglycaemic diabetic person. Irregular pulses, i.e. bradycardia, tachycardia or absent pulses, with no apparent explanation should be investigated with Doppler apparatus. Blood pressure
Hypertension is usually asymptomatic unless very severe. Symptoms usually indicate the presence of complications and include headache, nose bleeds and dizziness. It rarely causes oedema. Hypertension is a risk factor for many serious conditions such as MI, left ventricular failure, cerebrovascular accidents, aortic dissection and renal failure. There is a direct correlation between the degree of hypertension and the likelihood of a stroke, so blood pressure values can be one of the most reliable indicators for prognosis of life span; it is, therefore, one of the most useful screening exercises that can be carried out in the clinic. Simple non-pharmacological intervention is usually tried as a first-line method of treatment, unless the condition is severe, with drugs being used only if the situation does not respond or worsens. The pressure in the large arteries will vary during the cardiac cycle. The highest pressure will be at ventricular systole when blood is being forced into the arteries. The pressure at this point
VASCULAR ASSESSMENT
is called the systolic blood pressure. The lowest point is when the heart is relaxed, just before it begins its next contraction. This is called the diastolic pressure. The blood pressure is always written as systolic pressure/diastolic pressure. The value for a healthy adult is 120/80 mmHg (17/11 kPa). Pulse pressure is the difference between the systolic and diastolic pressures and will widen or reduce as either or both pressures change. The value of the systolic and the pulse pressures rises with age due to loss of compliance in the arterial tunica media. The taking of blood pressures by the auscultatory method is a simple technique but requires practice and attention to detail in the procedure (Fig. 6.11). Other methods such as the palpatory method are not considered to be as sensitive. The method was developed using mercury manometers, but increasing awareness of health and safety is seeing the gradual replacement of these by aneuroid manometers, which are not only safer but more user-friendly. Even easier to use are automatic manometers which display the blood pressure and heart rate on a liquid crystal display (LCD) panel although accuracy varies according to the model used. In the manual versions the manometer is connected to a rubber hand pump with a valve and an inflatable cuff and the following procedure should be adopted:
Figure 6.11
93
• The patient should be seated comfortably with one arm flexed at the elbow and resting at heart level on a flat surface. • The brachial pulse should be palpated. • The cuff should be wrapped around the selected arm of the patient, well clear of the brachial pulse point. • The pressure cuff should be inflated until the brachial pulse can no longer be palpated. The value of this pressure should be noted and the pressure released rapidly. • The diaphragm of the stethoscope should be placed on the pulse point and the pressure cuff re-inflated to the same value as previously obtained. Nothing will be heard at this stage. All vessels will be occluded so that no blood can flow through the artery. • The pressure should be released slowly and steadily, watching the needle on the manometer face (or the column of mercury fall). As the pressure falls to the level of the patient's systolic blood pressure a knocking sound will be heard in the stethoscope. At this stage the pressure in the cuff is sufficient to prevent flow of blood during diastole, but not during systole, so that the systolic flow can be heard. The reading of the manometer when the sound is first heard should be noted; this corresponds to the value of systolic blood pressure.
Diagram showing correct position of patient for measuring brachial blood pressure using the auscultatory method.
94
SYSTEMS EXAMINATION
• The pressure should continue to be released. The sounds will first increase then decrease in intensity and finally disappear. At this stage the pressure in the cuff is insufficient to occlude the artery at any stage in the cardiac cycle and this point is taken as the value for the diastolic blood pressure. • The practitioner should ensure that the cuff is deflated completely. The first person to describe this method was Korotkoff and the sounds heard are called Korotkoff sounds. Practice makes perfect! If the readings are not consistent, there are a number of ways in which errors may have been introduced: • The rubber tubing may be perished. • The valve may be faulty. • The cuff may be the wrong size for the diameter of the limb. • The arm may not be at heart level. • The practitioner may not read the values correctly. If in doubt, or if the values are not as expected, the exercise should be repeated, after the patient has had time to relax. Blood pressure values show a Gaussian distribution curve, so the values used to indicate hypertension are somewhat arbitrary. In the UK, hypertension for adults is taken as any systolic value over 160 mmHg and any diastolic value over 95 mmHg. Ideally, readings should be taken on three separate occasions since stress can cause a temporary rise in blood pressure. The most effective way of measuring blood pressure is by a self-monitoring technique. Patients measure their blood pressures at regular intervals throughout the day and an average value is obtained. The upper normal limit is lower in children and higher in the elderly.
Hospital tests These are performed both to confirm diagnosis and to identify the exact site of a problem so that accurate surgical therapy can be performed. Non-invasive Electrocardiogram. The electrical activity of the heart is recorded using limb and chest leads attached to the skin. Many pathologies of the
heart, such as MI or ventricular enlargement in a failing heart, will alter the normal PQRS waveform. Exercise may be used to highlight problems not apparent at rest. Chest X-ray. A standard radiograph of the chest will show such pathologies as enlargement of the heart, calcification of coronary arteries and malignant masses. Phonocardiography. This involves the application of a sensitive microphone to the chest wall, to allow heart sounds and murmurs to be recorded, but is now being superseded by echocardiography. Echocardiography. This uses ultrasound at a frequency of 2.5 MHz to visualise both the heart and the coronary arteries. It can visualise movement of ventricular walls, septum and heart valves (Kapoor & Singh 1993a). Electron beam tomography. A recently developed non-invasive procedure, electron beam tomography has been shown in a recent study to be more sensitive in detecting those patients at high risk of CAD than the more usual procedure of analysis of lipid cholesterol levels (Hecht & Superko 2001). Invasive techniques Blood analysis. Diagnosis of anaemia can be easily confirmed with a full blood count, where the number and volume of the red blood cell is calculated, as is the oxygen content (Ch. 13). Further investigations are then required to establish the cause. Where aplastic anaemia is suspected, a sample of bone marrow is analysed, usually from the sternum. During unstable angina or episodes of MI the ischaemic myocardial cells produce increased amounts of particular enzymes and metabolites, such as cardiac creatine kinase, which peak 24 hours after the attack, so that quantitative analysis of these substances aids diagnosis. Analyses of levels of low-density lipoprotein cholesterol (LDLC) and high-density lipoprotein cholesterol (HDLC) are used as screening processes, especially where a patient is at high risk of CAD, such as those with familial hypercholesterolaemia. Patients with levels of LDLC >130 mg/ dl (3.4 mmol zl) or with levels of
VASCULAR ASSESSMENT ---"--------"----------"-------"-"--"------"-----"-------
HDLC <35 mg/ dl (0.9 mmol/D are considered in the United States to have subclinical CAD (Hecht & Superko 2001). Coronary angiography. This involves introduction of a diagnostic catheter through the femoral artery into the left ventricle and associated vessels (Kumar & Clark 1990c). Pressures in various of the heart chambers and main vessels can be measured directly. Blood samples can be taken to measure oxygen content and ischaemic metabolites such as lactate and contrast cine-angiograms can be taken by injection of a radio-opaque dye at the site to be investigated. Digital subtraction angiography produces better-quality angiograms.
Table 6.3
Myocardial perfusion scintigraphy (radionuclide perfusion imaging). This is a very sensitive test
using exercise thallium-201 or technetium-99m imaging to detect coronary artery disease (Kapoor & Singh 1993b, Kumar & Clark 1990d).
PERIPHERAL VASCULAR SYSTEM It is important to distinguish between an impoverished arterial supply, reduced venous drainage and impaired lymphatic drainage, though of course more than one impairment may coexist.
ARTERIAL INSUFFICIENCY Medical history Conditions which can affect the arterial supply to the lower limb can be divided into those that lead to acute and those that lead to chronic problems (Table 6.3). Most arterial problems affecting the lower limb are chronic in nature, leading to peripheral arterial occlusive disease (PAOD) and resulting in ischaemia and poor tissue viability. The most common cause of PAOD, which is also called peripheral vascular disease (PVD), is atherosclerosis. This is a pathological process involving formation of a fatty plaque or atheroma in the intima of large and medium-sized arteries (Murphie 2001a). The atheroma itself causes no obstruction to blood flow, but its tendency to ulcerate promotes thrombus formation, which
95
Causes of arterial insufficiency in the foot
Acute
Extrinsic: light clothing tourniquet plaster cast trauma frostbite immersion foot Intrinsic: thrombosis embolus ruptured aneurysm oedema
Transient
(usually lead to acute problems but may progress to chronic) Raynaud's phenomenon Chilblains Hereditary cold fingers
Chronic
Atherosclerosis Vasculitis Thromboangiitis obliterans (Buerger's disease) Arteriolosclerosis?
causes narrowing (stenosis) or complete occlusion of the vessel. In addition, the thrombus is likely to embolise and be swept away to cause obstruction further down the arterial tree. There appears to be little evidence to suggest, as was previously believed, that a similar process occurs in the micro-circulation (Murphie 2001b). Although hyalinisation (arteriolosclerosis) and thickening of basement membranes and functional abnormalities of small vessels have been observed, these changes occur mainly in renal and retinal vessels, and are not considered to have major effects on the vascular status of the foot. Such changes mainly affect people with diabetes, but not exclusively. Much less common causes of PAOD are vasculitis, thromboangiitis obliterans and arterial emboli. Vasculitis is inflammation of blood vessels seen in a large number of rheumatic and connective tissue diseases. Any vessel can be affected, with the most serious consequences being in the arterial tree, resulting in partial or total occlusion. Some of the conditions associated with vasculitis are: • rheumatoid arthritis • systemic lupus erythematosus (SLE) • polymyositis
96
• • • • • •
SYSTEMS EXAMINATION
dermatomyositis systemic sclerosis polyarteritis nodosa giant-cell arteritis erythema nodosum Henoch-Schonlein syndrome.
Thromboangiitis obliterans is characterised by inflammatory changes in small and mediumsized arteries and veins. It mainly affects young males and there is a very strong association with smoking. All signs and symptoms of arterial ischaemia and superficial phlebitis of the hands and feet may be present. Eventually, distal necrosis occurs. Arterial emboli can be composed of any obstructive body that lodges in the smaller vessels of the arterial tree, causing ischaemia distally. The most common embolus is formed by fragmentation of a thrombus, such as a mural thrombus found on the endocardium, especially around the heart valves, or in the arteries, mostly at sites of bifurcation, where turbulence is most likely. Emboli may occlude arterioles and capillaries, causing isolated patches of digital necrosis. The source of such emboli may be septic thrombus from infection or deformed red blood cells as seen in sickle cell anaemia. Any history of previous MI, stroke or transient ischaemic attacks suggests the presence of atherosclerosis which, in addition to affecting the coronary and cerebral arteries, may also be affecting the arterial supply to the lower limb. A past history of vascular surgery such as coronary or femoropopliteal bypass grafting is also a good indicator that atherosclerosis may be present. A history of cryovascular disorders (e.g. chilblains, Raynaud's disease/phenomenon) should be noted as the attacks of vasospasm may become chronic and cause painful digital ulceration. (Case history 6.2).
Symptoms Inadequate blood supply to the lower limb leads to a range of signs and symptoms that are known as the six Ps: • pain
Case history 6.2 A 35-year-old female Caucasian first presented to the clinic when aged 24, complaining of broken skin on the toes. The patient presently lived alone as she had recently separated from her partner and she had a history of poor circulation to both hands and feet. Footwear was inadequate for winter, and foot hygiene was poor. Examination of the lower limbs revealed pale skin and cold feet. The lesser toes were held in flexion deformities. No hairs were present. The nail on the left fifth toe was black. The skin was tight, shiny and smooth. There were small, painful ulcers on the apices of toes and fingers. All ulcers showed signs of infection. Pedal pulses were palpable but feeble. Popliteal pulses were stronger. Ankle-brachial pressure indices at the dorsalis pedis artery for right and left foot were 1.0 and 0.97, respectively. There was no evidence of underlying systemic disease. A diagnosis of idiopathic Raynaud's disease was made. The condition was exacerbated by personal and social factors. The repeated breakdown of lesions, as detailed in the patient's record over the past 4 years, was due to the underlying vasospastic disorder, which was worsened by cold weather, selfneglect and emotional upsets. Current treatment was successful in healing the lesions but without continued patient compliance the overall prognosis is poor.
• • • • •
pallor pulselessness paraesthesia paralysis perishing cold.
Pain is usually associated with arterial insufficiency. It is important that the site, nature, duration and aggravating factors of the pain are recorded. This information can be very helpful when assessing the prognosis of diseases that affect the arterial supply. Inadequate blood supply to respiring tissues may be an acute situation, producing a characteristic range of signs and symptoms, including pain, pallor and lack of pulses. When the deficiency is prolonged, the tissues eventually suffer irreversible damage and this stage can be recognised by mottling, muscle tenderness, motor or sensory deficit and necrosis. Continuation of the condition will lead to a chronic state of insufficiency, accompanied by pain on exercise, or even at rest if very severe, and necrosis and ulceration. The following types
VASCULAR ASSESSMENT
The Fontaine classification of peripheral vascular disease (PVD)
Table 6.4
Stage
Symptoms
2 3
Occlusive arterial disease but no symptoms (due to collaterals) Intermittent claudication Ischaemic rest pain (usually worse at night, relieved by dependency) Severe rest pain with ulceration/necrosis (gangrene)
4
of ischaemic pain can occur and lead to the Fontaine classification of PVD (Table 6.4). Intermittent claudication
Just as angina pectoris indicates insufficient blood supply to the myocardium, so intermittent claudication indicates inadequate blood supply to the periphery. When the blood supply is inadequate, the deficiency will be accentuated on exercise. The exercising muscles have to respire anaerobically and produce metabolites which are not cleared by the blood. These cause ischaemic pain, which forces the patient to stop the activity. Resting for a few minutes reduces the amount of metabolites produced and allows the patient to continue walking for a further period. The distance walked before onset of the pain is called the ischaemic or claudication distance and is a good indication of the severity of the condition. The exercise should be standardised, e.g. 4 minutes at 0% incline at 4 km/h (Lainge & Greenhalgh 1980). The site of the ischaemic pain is an indication of the site of the occlusion. It should be borne in mind, however, that patients with neuropathy may not complain of intermittent claudication. Night cramps
If the blood supply is more severely compromised, the patient will experience night cramps, which are alleviated by dangling the legs over the side of the bed or walking on a cool floor. The warmth of the bedclothes increases the metabolic rate of the tissues and so increases their demand for oxygen; this cannot be met and produces ischaemic pain. Using gravity to
97
aid flow and cooling the limb helps to reduce metabolic activity. Rest pain
This is the most severe condition of critical limb ischaemia. Here the blood supply is inadequate even at rest, walking is impossible and the only way that the peripheral tissues can obtain any blood is by gravity. The legs must always lie below the level of the heart, either by raising the head of the bed or by sleeping in a chair. Even contact of the bedclothes on the limbs may be too painful. Cages are sometimes used to protect the limbs.
Observation While an experienced practitioner can glean considerable information from simple observation, it is important not to rely on these observations alone, but to view them as part of the whole picture. The patient should be seated on a couch in a comfortably warm room. Colour
Table 6.5 shows the range of colour changes seen in the lower limb and their significance. Tissue viability Hairs. A poor blood supply leads to inadequate nourishment for skin and soft tissues. The skin will appear thin, shiny, and dry with absent hairs (Plate 1). Friction from boots and depilatories could be less worrying causes. Atrophy. In chronic situations atrophy (wastage) of soft tissue, including muscle, will also be present. This is especially noticeable on the plantar surface of the foot. In severe limb ischaemia, muscle tone will be lost and the limb will appear lifeless.
Ischaemic ulcers
An impaired peripheral circulation makes ulcers more likely to develop as the tissues are unable to
98
SYSTEMS EXAMINATION
Table 6.5
Interpretation of colour changes in the lower limb
Colour
Causes
Pink White/pale White below demarcation line Blue (peripheral cyanosis) Blue seen with central cyanosis Hazy blue Red
Healthy circulation Cold, anaemia, chilblains, Raynaud's phenomenon, cardiac failure Severe ischaemia Cold, chilblains, Raynaud's phenomenon, venous stasis Cardiac/respiratory failure Infection, necrosis Heat, exercise, extreme cold (cold-induced vasodilation), inflammation, infection (cellulitis), chilblains, Raynaud's phenomenon Haemosiderosis, moist necrosis Bruise, shoe dye, necrosis
Brown Black
withstand the normal daily stresses on the lower limb. The characteristics of the lesion can assist in diagnosis of the circulatory problem, since ulcers caused by ischaemia differ in many respects from those caused by other deficiencies such as poor drainage or neuropathy (Ch. 17). Ischaemic ulcers are caused by trauma and are usually very painful, unless there is neuropathy present, as for example in some diabetic patients. There is lack of granulation tissue and low amounts of exudate, but slough is often present. The borders are well demarcated and they may have a 'punched out' appearance (Plate 2). They often occur first under the toe nails, on the apices of the toes or around the borders of the feet, a contributory factor usually being tight or ill-fitting footwear. Leg elevation can exacerbate the pain, whereas lowering the leg into dependency can improve the blood supply and ease the pain. Ischaemic ulcers are unlikely to heal unless there is an improvement in blood supply. Ulcers of any type are less likely to heal if the patient is on medication which reduces cardiac output, e.g. beta-blockers.
regions being affected first. The tissue will appear hard, black and mummified, with a clear demarcation line between dead and living tissue (Plate 3). Ulceration and infection may cause a septic vasculitis, which again leads to ischaemia and necrosis, but here the tissue remains moist and usually has a distinctive smell. This is wet gangrene. Pus and infection of surrounding tissue is present. The presence of proximal arterial occlusion and poor collateral development may be contributing factors. Oedema
Oedema is not usually associated with poor peripheral arterial supply. If present bilaterally, the cause is likely to be a central one such as congestive heart failure. Unilateral or localised oedema may be due to infection, trauma, allergy or impaired venous or lymphatic drainage (Table 6.6).
Clinical tests Nails
Poor blood supply will affect the nails. These may be crumbly, discoloured or thickened. They are prone to fungal infection and pitting. The latter should be differentially diagnosed from dermatological conditions such as psoriasis (Ch. 9).
The following tests should be repeated for both lower limbs and require none or very simple apparatus of the type usually found in a practitioner's clinical environment. Again some of these tests are of greater significance than others in aiding diagnosis.
Necrosis (gangrene)
Temperature gradient
Severe ischaemia, if unrelieved, will progress to necrosis or dry gangrene, with the most distal
The back of the practitioner's hand should be used to stroke the anterior surface of the patient's
VASCULAR ASSESSMENT
Table 6.6
99
Differential diagnosis of oedema of the lower limb Causes
Cardiac failure
Venous stasis
Primary lymphoedema
Secondary lymphoedema
Bilateral Transudate Pitting Acquired Post myocardial infarction
Unilateral Transudate Pitting Acquired Post immobilisation
Bilateral Exudate Non-pitting Congenital
Unilateral Exudate Non-pitting (unless very long-standing) Acquired Post-infection, radiotherapy, surgery, malignancy
lower limb from the knee to the toes. The proximal part of the leg should feel warm to the touch, with a gradual cooling as the feet are approached. On a cold day the toes can feel very cold; this is quite normal but a sharp temperature drop on a comfortably warm day will suggest an inadequate blood supply, with possibly an obstruction occurring at the level of the sudden change. Remember too, that the temperature felt is relative to the temperature of the hand of the practitioner. This problem can be overcome by measuring skin temperature with a simple probe thermocouple attached to a hand-held digital display unit. Any difference between the two limbs of more than 2°C should be investigated further. Capillary filling time (CFT)
CFT is gradually falling into disuse as it has failed to show a correlation with gold standard measurements such as transcutaneous oxygen tension (Tcp02) values, being replaced by more meaningful tests. To be strictly accurate, it is not the capillaries but the subpapillary venous plexus which is responsible for colour in the skin and is blanched by digital pressure. The time is noted in seconds for the blood to return after blanching. Normal colour should return within 2-3 seconds on a warm day and within 5 seconds on a cold day. Absence of blanching in a cyanotic foot indicates that the tissues are devitalised. Buerger's elevation/dependency test
The leg should be elevated until all the veins in the dorsal arch of the foot have emptied. The
plantar surface of the foot will appear pale as blood will have drained out of all superficial vessels due to the effects of gravity. The blood can be stroked from the raised limb to accelerate the gravitational effects. A mild pallor should then be seen within 1 minute. A severe, widespread pallor suggests arterial insufficiency. The limb should be lowered into dependency and the time taken for the plantar surface to return to the colour of the other limb or for the dorsal veins to refill should be noted. If the blood supply is adequate, the plantar surface of the foot should regain its normal colour within 15 seconds. A delayed time of 20 seconds or more suggests that blood supply is inadequate, with severe ischaemia being likely if the delay is 40 seconds or more. If the colour on dependency is a dusky red, this is a serious sign, indicating that the blood supply is severely compromised. Buerger's test has been shown to be a useful adjunct to routine vascular assessment and can be an indicator of more severe ischaemia with distal limb artery involvement (Ins all et al 1989).
Allen's test
This can be used to detect occlusion distal to the ankle. One leg of the patient is elevated and the dorsalis pedis artery is compressed with the practitioner's thumb. Maintaining pressure on the artery, the leg is lowered into dependency. If the tibialis posterior artery is patent, the foot should return rapidly to its normal colour. The patency of the dorsalis pedis artery can be tested in a similar manner, by compressing the tibialis posterior artery.
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SYSTEMS EXAMINATION
Pedal pulses Each time the heart contracts, blood is ejected into the aorta from the left ventricle. Because the aorta has a large amount of elastic tissue in its walls, the walls will be distended by the blood. At diastole, as the heart relaxes, the pressure on the walls drops and the elastic recoil of the walls causes them to spring back, pushing the blood on and acting as a secondary pump. The recoil causes a pressure wave, which travels rapidly through the blood in the arterial tree. It travels much faster than the actual velocity of the blood, rather as
ripples can travel rapidly over the surface of a slow-moving stream. It is called a pulse (wave) and can be palpated wherever the arterial tree comes close to the skin surface, e.g. wrist. The main pressure points in the lower limb are indicated in Figure 6.12. These places are called pulse points or pressure points. The frequency of the pulse wave will be the same as the frequency of the heartbeat, or the ventricular systole. The practitioner should place the thumb or second, third and fourth digits on the dorsalis pedis pulse point; the number of shock waves in
c
B
D Figure 6.12 E. Femoral.
Location of pulses in the lower limb
A. Dorsalis pedis
B. Anterior tibial
C. Posterior tibial
D. Popliteal
VASCULAR ASSESSMENT
1 minute should be counted. This procedure should be repeated at the posterior tibial pulse point and for the other leg. When the practitioner is familiar with this technique, the time can be reduced to 30 or 15 seconds, with the score being doubled or quadrupled appropriately. This is slightly less accurate than taking the pulse for 1 minute. If the arteries are all patent and there is no vascular problem, then the values should be identical at each site. If they are not, the pulses should be checked again. If the pulse appears to be absent, it may suggest that there is some occlusion in the artery, proximal to the pulse point. This will either produce a faint pulse or an absent one. The site which is immediately proximal to the absent pulse should be tried to see if the approximate area of obstruction can be located. If the pulse cannot be located, the site should be investigated using a Doppler machine. However, it should be noted that the dorsalis pedis pulse is absent in 10% of the population and the posterior tibial pulse is absent in 2%, but only 0.5% have both absent in the same foot. Due to the many anastomoses between pedal vessels, there is some justification in the view held by some practitioners that one patent artery per foot is sufficient to avoid critical limb ischaemia. A large pulsatile mass behind the knee or in the inguinal area suggests the presence of an arterial aneurysm: 10% of aneurysms occur in the popliteal fossa. They should be differentiated from popliteal cysts. Aneurysms are liable to rupture or stagnate in the area, which may lead to thrombus formation. Bruits
Bruits are abnormal sounds which can be heard, using a stethoscope, in the arterial part of the cardiovascular system. Normal flow is laminar and is silent. Bruits are due to turbulence in arteries caused either by an increased velocity or an obstruction. Nicholson et al (1993) consider that clinical examination for bruits has good accuracy (78%) and may be of clinical value in the early detection of patients who are suitable for percutaneous angioplasty.
101
Doppler ultrasound
The Doppler ultrasound machine enables the pulse to be heard much more clearly. The machine consists of two piezoelectric quartz crystals, one of which emits sound waves of very high frequency (2-10 MHz). The degree of penetration of the wave is inversely proportional to its frequency. It is recommended that a 4 or 5 MHz probe is used for deep vessels such as the femoral and popliteal arteries and an 8 or 10 MHz probe is used for superficial vessels such as pedal arteries (Huntleigh Diagnostics 1999). The waves are reflected off moving objects such as blood cells and received back by the second crystal. The difference in frequency between the emitted and reflected waves is emitted as a sound, the frequency of which is proportional to the velocity of the moving object. To obtain more information the output may be fed into a hand-held or a computerised chart recorder to produce a visible tracing (Fig. 6.13). To protect the head of the probe, a water-based coupling gel must always be used on the skin surface. For best results the pulse should be palpated and a blob of gel placed on the site. The probe should be placed at an angle of 45° to the skin surface and gently moved until an artery is located. When using a trace, always angle the probe proximally so that the systolic flow is detected as flow towards the probe, showing as a positive waveform, and reversed flow showing as a negative waveform. Most machines used in the community setting are the hand-held miniDoppler versions, although more sophisticated versions are used in cardiovascular laboratories. In its normal vasoconstricted state, the arterial pulse is unmistakable as three clear sounds, a triphasic response, the first being louder and of a higher pitch. This is due to the ventricular bolus being ejected from the heart during systole. The second and third sounds are the diastolic sounds, due to the reversal of flow caused by the elastic distension in the arteries and a final forward flow as the arteries rebound. The diastolic sounds correspond to the 'dichrotic notch' seen on Doppler traces, which will show two forward components and one reverse component (Fig. 6.13A). Loss of the reverse flow component or dampening of the
102
SYSTEMS EXAMINATION
systole
A A triphasic trace typical of a healthy lower limb artery. Note the reverse flow has started before the forward flow has ended.
B A biphasic trace typical of a lower limb artery distal to a stenosis. Note dampened wave form and loss of reverse flow.
c A trace typical of a popliteal vein with intact valves during compression and release of the vein.
D A trace showing the typical pattern of valvular incompetence in a vein.
compression
release
Figure 6.13 Doppler traces A. Triphasic trace typical of a healthy lower limb artery. Note the reverse flow has started before the forward flow in the systolic phase has ended B. A biphasic trace typical of a lower limb artery distal to a stenosis. Note dampened waveform and loss of reverse flow C. A trace typical of a popliteal vein with intact valves during compression and release of the vein D. A trace showing the typical pattern of valvular incompetence in a vein.
VASCULAR ASSESSMENT
waveform indicates disease (Fig. 6.13B), although a diphasic response can be seen with ageing as the vessels lose compliability (Case history 6.3). Forward and reverse flow simultaneously suggests turbulence, as would occur just distal to a site of stenosis. A monophasic response always indicates disease, but care must be taken first to ensure that the technique is not at fault. Patients with bradycardia will have a weak triphasic sound and patients with tachycardia will show only a biphasic sound as the heart is beating too rapidly for reverse flow to occur. The amplitude of the waveform is not significant since it depends on the angle of the probe. Claudication distance If the patient complains of intermittent claudica-
tion or if pedal pulses seem weak or absent, this test can be used to give an indication of the severity of the arterial occlusion. The patient is exercised, preferably on a treadmill, as the exercise should be standardised, and the distance the patient walks before the onset of pain is noted. The treadmill should be at 0% incline and at a speed of 4 km/h. No patient should be exercised if there is a history of angina and it is recommended that a full resuscitation kit should always be present for any exercise test.
103
Ankle-brachial pressure index (ABPI)
This was first described by Yao in the 1960s. The ankle-brachial index provides a good indication of the presence of ischaemia in the lower limb. It can be used quantitatively since it also correlates well with the patient's symptoms, walking distance and angiography. It can be used to determine the optimum level of amputation and prognoses for grafts (Ameli et al 1989, Davies 1992). The ankle-brachial pressure index is arrived at by recording the systolic pressure at the brachial artery and at the posterior tibial artery (ankle). Practitioners may find Doppler easier to use than a stethoscope when trying to take a reading of the systolic pressure in lower limb arteries. The reading obtained for the ankle is then divided by the brachial systolic reading and is expressed as a ratio. The value obtained at the ankle will depend on the position of the patient. If the person is supine and the legs are at the same horizontal level as the heart the ratio should be 1. If the person is sitting or standing, the pressure in the artery at the ankle will be greater than in the arm, because of the vertical column of blood between heart and ankle. As a rule of thumb the ankle systolic pressure will be 2 mmHg higher for every inch below the heart. Thus the ratio will be greater than 1. Average
1--····----·-----·- -----.--------------.----
I I
Case history 6.3 ------------------------------_._--_._--------_._-------
A ss-year-old female Caucasian presented to the clinic with an ulcer of 12 months' duration over the right medial maleolus. The patient complained that the skin had been itchy prior to the ulcer occurring and had developed following a knock to the right ankle. Pain was worsened on standing for long periods and relieved by elevation of the legs. She had no symptoms of paraesthesia or claudication. Examination of the lower limbs was remarkable for pitting oedema, varicose veins, haemosiderosis, atrophe blanche and gravitational eczema in the distal third of the right limb. The skin was warm, pedal pulses were bounding and regular (70 beats per minute) in the left foot but pedal pulses in the right foot could not be palpated because of the oedema. Both right pedal pulses were located with Doppler and gave a regular, biphaslc signal. There was no evidence of trophic changes to skin or soft tissue. An ischaemic (anklebrachial) index was not undertaken on the right leg
because of the ulceration present. The ischaemic index for the left leg was 1.2. The Doppler signal of the popliteal vein in the popliteal fossa indicated venous reflux. The past medical history revealed that the patient had suffered a deep vein thrombosis while recuperating from a major abdominal operation when 20 years old. The thrombosis had been treated effectively at the time but the patient had noticed some 10 years later that her right leg began to ache and feel heavy after prolonged standing. When she was about 40 years old her ankle started to swell towards the end of the day and by the time she was 50 the skin around the area had become discoloured and itchy. Despite a range of treatments the ulcer had not healed. A diagnosis was made of venous ulceration, as a result of post-thrombotic complications. These ulcers are notoriously difficult to heal and account for the majority of lower limb ulceration.
104
SYSTEMS EXAMINATION
values for healthy adults in the sitting position are 0.98-1.31 (Davies 1992). A ratio which is greater than 1 does not always mean that all is well. Elderly patients may show calcification of the tunica media of muscular arteries (Monckeberg's sclerosis) which, although independent of any atherosclerotic process and clinically insignificant, leads to incompressibility and a false high systolic pressure value. People with diabetes are also prone to calcification of the artery wall (not to be confused with Monckeberg's sclerosis), again leading to incompressibility of the artery. Nevertheless, 'the measurement of ankle pressure using Doppler is the single most valuable adjunct to the assessment of the blood supply to the foot' (Faris 1991). Any value below 1 should be checked again. Values less than 0.8 suggest some obstruction in the more proximal part of the artery to the lower limb, although it is possible to find no associated lesions in such patients. Values of 0.75 or less indicate severe problems, and at values below 0.5 healing is unlikely to take place, the leg being in a pre-necrotic state. Critical limb ischaemia is said to be present when the ankle systolic pressure falls below 50 mmHg or the toe systolic pressure falls below 30 mmHg (Lowe 1993). Ischaemic ulcers may be present. If severe ischaemia is suspected, but a high ABPI is obtained due to calcification, the Pole test can be used to calculate the ABPI (Smith et al 1994). The Pole test is a variation on the Buerger test using a mini-Doppler machine. With the patient supine, the suspected pedal artery is located and the affected leg raised until the pulse can no longer be heard. The vertical distance between the heart and this point is noted. Ankle systolic pressure is calculated using the formula 13 cm == 10 mmHg. Values of less than 40 cm (31 mmHg) suggest severe occlusion. Calcification will have no effect on this reading, but the method is limited to those patients with pressures less than 60 mmHg. It is also worth remembering that the peroneal artery is usually spared from calcification. Since mild to moderate atherosclerotic change may not affect the resting ABPI the effects of exercise on the index are often observed (Davies
1992). Again a standardised treadmill exercise should be used (4 km/h, 0% incline, 4 minutes). In a healthy adult, unless exercise is severe, the index will show no change or will rise but rapidly returns to resting value once exercise has stopped. In a person suffering from peripheral vascular disease, the index will not rise and may fall, taking a long time to return to resting values. Heavy exercise may produce a fall in the index in healthy subjects due to shunting of blood from the distal arteries to the exercising muscles. If the patient cannot be exercised, the hyperaemic test can be used. A second occlusion cuff is placed proximal to the first and inflated to above the systolic pressure for 2 minutes or as long as the presence of ischaemic pain will allow. It is then deflated and the systolic blood pressure is immediately taken. The second cuff occludes the arterial supply. Since venous drainage is also temporarily interrupted, metabolites will accumulate in the area. These have a vasodilatory effect on the blood vessels, so that in a healthy person, on releasing the second cuff, blood will rush into the area, producing a temporary hyperaemia. This will cause a slight rise in systolic blood pressure and so raise the value of the ABPI, but will quickly return to normal values. In a patient with peripheral vascular disease the narrowed arteries will be unable to respond to the vasodilatory effects of the metabolites, either because they are unable to dilate or because the occlusion prevents an increased flow, so that the ABPI will either stay the same or fall. If a low ankle-brachial index is recorded, the index should be calculated at progressively higher positions up the leg, to ascertain the site of the occlusion. When using the ankle-brachial pressure index it is also important to remember that the value obtained for the ankle cannot accurately predict the healing of lesions in the forefoot although pedal arteries are rarely affected by atherosclerosis. Digital cuffs can be used to assess the systolic reading in toes. A Doppler head of 10 mHz is preferable although not essential. ABPI of the peroneal nerve, toe pressures and analysis of the Doppler waveform will give a reliable indication of the presence of significant ischaemia, which will be revealed as reduced
VASCULAR ASSESSMENT
ABPI, reduced toe pressure and dampening of the Doppler waveform. The cardinal signs of ischaemia can be summarised as follows: • diminished or absent pedal pulses • ABPI <0.9 • ischaemic pain.
Hospital tests If an ischaemic limb has been identified, further
investigation may be required to assess: • suitability for reconstructive surgery • the prognosis for the healing of ulcers • the level at which amputations should be performed. Macrocirculation Duplex ultrasound. This xornbines B mode
ultrasound and Doppler to give both an image of the artery under investigation and the flow within that artery (Banga 1995). It takes time and requires a level of expertise, but using Doppler and pulse-generated run-off (PGR) a complete non-invasive assessment of the lower limb can be achieved, which reduces the need for contrast angiography. Angiography (arteriography). At present this procedure, especially using intra-arterial digital subtraction angiography, remains the gold standard for imaging the arterial supply of the lower limb. A needle is inserted into the femoral artery and a radio-opaque dye is injected just proximal to the occlusion. It can be used to locate occlusions and stenotic vessels and to determine whether a collateral circulation has been established. It is used to help determine the most appropriate revascularisation procedure and, if a bypass procedure is to be performed, the site of the distal anastomosis. It also is used to predict the prognosis for limb salvage and graft patency. It can also be used during surgery, to enable the surgeon to have an accurate picture of distal runoff. Being an invasive procedure, it carries more risks than non-invasive procedures, which are likely to replace it as technicalities improve.
105
Magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning. These are
expensive, more recent procedures which can be used to visualise the various parts of the circulation. Initially, doubts were raised as to the value of such procedures in the absence of evidence to suggest any improvement in patient outcome (Kapoor & Singh 1993c) but recent improvements in resolution using gadolinium enhancement now enable imaging of digital vessels as small as 1 mm diameter and have led Mercer & Berridge (2000) to consider magnetic resonance angiography as the modality of the future, eventually replacing contrast angiography. Microcirculation Capillaroscopy. With the patient in a sitting position, the capillaries of the pedal nail fold can be examined, using an oil immersion microscope under a strong light. The nutritive capillaries are distinct and well filled with blood in a person with no arterial disease but, as ischaemia progresses, the capillaries become hazy and less distinct. Capillaroscopy can be used to predict those patients likely to develop critical limb ischaemia as well as the likelihood of healing of ischaemic ulcers. Transcutaneous oxygen tension (Tcp02)' The skin is heated to arterialise the capillaries and the oxygen which diffuses to the surface of the skin equilibrates with an electrolyte solution held in a small chamber on the skin. The partial pressure of oxygen in the solution is measured by an electrode which screws into the chamber. This value reflects the difference between oxygen supply and consumption in the local tissues. Severe ischaemia is indicated if the value is below 40 mmHg, when healing will be unlikely. This is not a routine test but can be used as a predictor of level of amputation and of the success of angioplasty. Photoelectric plethysmography. This method is used to measure skin blood pressure. A lightemitting diode is placed on the skin and a photocell is used to detect the emitted light, which is proportional to the amount of haemoglobin in the tissues. A sphygmomanometer cuff is used to
106
SYSTEMS EXAMINATION
blanch the skin. The cuff is then slowly deflated and the pressure point at which a flow signal returns is taken to be the skin perfusion pressure. A similar piece of apparatus is used to measu~e oxygen percentage saturation of the blood m pulse oximetry (Coull 1988). . Isotope clearance. This method IS used to measure skin perfusion pressure (SPP) and skin vascular resistance (SVR) in the compromised foot in order to ascertain the likelihood of the healing of ischaemic ulcers. The SVR can be calculated from the graph of clearance values and applied pressure. A straight-line ~elations~ip exists between the two and the SVR IS the reCIprocal of the slope. A small volume of the radioisotope technetium-99m, together with a vasodilator such as histamine, is injected into the skin and the rate of clearance of the isotope is recorded. The pressure from a sphygmomanometer cuff just necessary to prevent the radioisotope from leaving the area is taken as the SPP. This value reflects the degree of large artery disease. A value of 30 mmHg or more is needed to ensure healing. Radionuclide imaging as performed for investigation of coronary arteries can also be used to estimate blood flow in the foot and to detect the presence of osteomyelitis (Faris 1991). Laser-Doppler fluximetry. This measures the movement of red blood cells in cutaneous vessels, which changes as ischaemia progresses and so can be used to determine amputation level.
VENOUS DRAINAGE Venous problems may arise in the superficial, communicating and/or deep veins (Table 6.7). Superficial veins lie in the superficial fasci~, d~ep veins lie in skeletal muscle and communicating veins link the two. There are three main pathological processes affecting veins, which can be interlinked: • absent or incompetent valves • formation of a thrombus which may trigger secondary inflammation of the vein wall (thrombophlebitis)
• inflammation of the vein wall (phlebitis) with possible secondary formation of a thrombus (phlebo-thrombosis). The first condition affects superficial or communicating veins. The cause may be congenital, where family history is common; be caused by increased pressure, such as occurs during pregnancy; or an abdominal tumour or ascites which causes venodilation and renders the valves incompetent. Much less common are congenital conditions causing swelling or dilation of veins. The resulting back flow due to gravity leads to increased hydrostatic pressure in the lower limb veins, giving rise to the knotty appearance of varicose veins. The second and third conditions can affect superficial or deep veins, but part of th~ s.equela.e of deep vein pathology is often superficial vancosities. Phlebitis with no thrombosis affects superficial veins, usually as a result of trauma or infection. Causes of venous thrombi are multifactorial, being any factors which contribute to Virchow's triad of: • stasis • hypercoagulability • injury to the endothelium. Patients suffering from recurrent thromboses show a familial tendency and an association has been demonstrated with a mutation for genes Table 6.7
Causes of venous insufficiency
Type
Cause
Superfical
Varicose veins: primary - idiopathic secondary - backflow from deep to superficial vein Thrombophlebitis Phlebangioma (congenital swelling of vein) Phlebectasia (congenital dilation of vein)
Deep
Deep vein thrombosis due to: abnormalities affecting blood flow abnormalities of clotting abnormalities of endothelium Idiopathic Thrombophlebitis
VASCULAR ASSESSMENT
coding for coagulation factor V, with greater incidence among Caucasians than other ethnic groups (Khachemoune et al 2001). The presence of a thrombus in the deep veins, whether causing or following an inflammatory response, is much more serious than its presence in a superficial vein as it will lead to chronic venous insufficiency and the stasis syndrome (post-thrombotic syndrome) in approximately a quarter of these cases with the further risk of pulmonary embolism. The incidence of deep vein thrombosis (DVT) in the United States is 1:1000 with death from pulmonary embolism being 1-2% (Khachemoune et al200l).
Past history As varicose veins and recurrent deep vein thromboses tend to have a familial predisposition, it is important to ask the patient if anyone else in the family suffers from the condition. Varicose veins may be part of the post-thrombotic syndrome (Case history 6.3) but do not always indicate previous DVT. Patients should be asked if they have previously suffered with any venous problems, e.g. DVT. Women of childbearing age may have experienced a DVT during, or more probably shortly after, childbirth. Although this may have occurred some years ago, it may be the underlying cause of current venous problems.
Symptoms Uncomplicated varicose veins may be asymptomatic but present a cosmetic problem to many women. Where superficial veins are affected by phlebitis the vein and surrounding area will be tender with erythema or cellulitis. If thrombophlebitis is present the vein will be palpable as a linear, indurated cord and is usually associated with tenderness, erythema and warmth. A bursting or aching sensation associated with ankle oedema suggests problems with the deep veins. The pain and oedema are often alleviated by leg elevation. The onset of DVT can be asymptomatic or be associated with severe pain, tenderness and warmth in the calf. A ruptured
107
popliteal cyst, as sometimes occurs in patients with rheumatoid arthritis, may cause similar symptoms. If a DVT is suspected, it is not advisable to use any diagnostic test which increases pressure on the calf, such as detection of Homans' sign, as this increases the risk of embolism. Because of the direction of venous flow proximally and centrally, venous emboli will be swept through increasingly larger vessels and emptied into the heart. From here they will enter the pulmonary circulation and only here are the vessels small enough to stop the embolus. Occlusion of the main pulmonary vessels (pulmonary embolism) prevents any gaseous exchange, often with fatal consequences.
Observation Hosiery
The wearing of elastic or support stockings or bandages suggests some problem with venous drainage. The extra compression provided by the stocking aids venous blood flow and reduces peripheral oedema. Colour
Telangiectases (dilated microvasculature) around the medial malleolus can indicate poor drainage (Plate 4). A mottled cyanosis may appear in the lower third of the lower limb due to stagnation of blood in the veins as a result of poor drainage. Atrophie blanche, white patches on the skin around the ankles, occurs due to strangled microcirculation and leads to fibrotic and sclerotic changes in the skin (Plate 5). Brown iron complexes of haemosiderin may be deposited in the tissues as a result of increased hydrostatic pressure (Plate 6). Differential diagnoses from haemosiderosis are erythema ab igne, common in the elderly, and necrobiosis lipoidica diabeticorum, a condition associated with diabetes, where yellowish patches are seen on the shins and the skin appears very transparent, so that superficial blood vessels can be seen.
108
SYSTEMS EXAMINATION
Temperature
In venous insufficiency the skin often feels warm, which suggests that the arterial supply is satisfactory. However, it should be borne in mind that recent thrombosis or venous embolus may trigger inflammation in the veins (phlebitis). Another cause of phlebitis is infection. Cellulitis, general malaise, a rise in core temperature and a portal of entry will be strong indicators of the presence of infection.
Varicose veins
These may be due to incompetent valves in the superficial or communicating veins alone or as a consequence of DVT. Back pressure due to an obstruction in the deep veins will accumulate through the communicating veins to the superficial veins. This causes the superficial veins to become incompetent and forward flow of blood is deficient. These veins are very extensible, with non-uniform areas of weakness, and have little support in the superficial tissues; therefore, they bulge unevenly due to the pressure of blood, giving the knotted appearance of varicose veins. Varicosities are especially apparent on standing. Poor tissue viability results, which may lead to cellulitis or superficial phlebitis, where the vein will be cord-like and painful. If such a cord can be palpated in the calf area, this does not indicate DVT, as the vein involved is again a superficial one. Tissue viability
Poor drainage results in the accumulation of waste products. As a result, tissue viability is adversely affected. The skin may eventually become indurated. If the stasis is a consequence of DVT, atrophy, venous (gravitational) eczema and venous ulcers may result. Gravitational (stasis) eczema
Signs of discoloration and pigmentation, scaly and lichenified skin, in the presence of oedema, haemosiderosis and atrophie blanche suggest a
diagnosis of gravitational eczema (Plate 6). The area can be very pruritic; scratching may lead to the development of ulcers. Patients with gravitational eczema often find that they become sensitised to topical antibiotics and to preservatives in other topical medicaments and bandages. Venous ulcers
These account for 85% of all leg ulcers and are more common in women than men. They are commonly found around the malleoli, in particular the medial malleolus, but can spread completely around the leg and when healed, form unsightly scars (Plate 7). Venous ulcers are associated with the post-thrombotic syndrome, including gravitational eczema; they are rarely a consequence of superficial varicosities. They are usually shallow with irregular borders and have either a healthy or slightly sloughy base unless infected (Plate 8) (Ch. 17). Trauma is not always the initiating factor. Venous ulcers are usually only painful if they become infected. The pain can be alleviated by leg elevation. Bacterial infection is very common in long-standing ulcers, which become malodorous and a source of considerable misery and embarrassment to the patient. These ulcers are notoriously indolent. It is not unusual for a patient to have suffered a venous ulcer for many years which, despite daily attention, refuses to heal (Case history 6.3). In most cases, this is because adequate compression is not applied. In some cases malignant change, squamous cell carcinoma, may occur. It is important that the practitioner regularly monitors these ulcers for signs of malignant change such as rolled edges and a hyperplastic base. Oedema
Oedema may be associated with venous problems (Plate 8), occurring as part of the sequelae to DVT. The increased hydrostatic pressure causes leakage of tissue fluid, so that oedema results. If the oedema is not controlled, the symptoms of postthrombotic syndrome will develop. Where the tissue fluid is an exudate, it will contain plasma
VASCULAR ASSESSMENT
proteins, including fibrinogen, and will become organised. Transudate will not become organised unless it is very long-standing. Once the oedema is organised it cannot be squeezed by digital pressure and so is called non-pitting. The oedema due to DVT usually demonstrates pitting unless it is very long-standing. There will often be an outline of the patient's hosiery or footwear impressed on the skin. Oedema may result in ischaemia around the ankle. In these instances moist gangrene may occur if the occlusion of arteries is very severe. The different types of oedema which can occur in the lower limb and their differential diagnosis are shown in Table 6.6. Leg shape
Patients with chronic venous ulceration and oedema may develop characteristic 'champagne legs', also known as 'inverted bottle legs'.
Clinical tests Pitting/non-pitting oedema
Digital pressure is firmly applied to the area for a period of 3-5 seconds. If an imprint of the fingers remains, the oedema is described as pitting. Perthes test
This can be used to test the competency of leg veins. With the leg dependent, an occlusion cuff is inflated at mid-thigh level. The superficial veins will become prominent as they fill. The patient is then asked to walk for 5 minutes. If the veins are healthy, the prominence will reduce due to drainage into the deep veins. If the superficial veins are incompetent, the prominence will remain and if this is accompanied by a dusky rubor it suggests that the deep veins are incompetent. Doppler
In contrast to the pulsating sounds of arteries, veins give a non-pulsatile, continuous, low-
109
pitched sound, like wind sighing down a chimney, because of the effects of respiration on the flow of venous blood in the thorax. On a chart the venous trace shows as an irregular, continuous wavy line with flow away from the probe (Fig. 6.13C). However, if there is excessive fluid in the lower limbs, as in congestive heart failure, the veins may give a pulsatile sound. The Doppler machine can be used to test for valvular incompetence of the calf veins as follows. With the patient standing and knee slightly flexed, the Doppler probe should be positioned over the vein in the popliteal fossa (it may be easier to locate the popliteal artery and then move the probe slightly sideways until the vein is located). The practitioner should squeeze and release the calf, distal to the probe. Two sharp sounds should be heard. The first sound is forward flow towards the probe as the vein is squeezed and the second sound is reverse flow due to gravity on release of the pressure. If there is no sound on compression this indicates a blockage between site of compression and probe. If the second sound is not abrupt, but continues and fades away, it suggests leakage of blood through the valves. This will be seen on a chart recording as a sharp peak, corresponding to flow towards the probe and a rapidly rising and much slower descending, irregular trace in the opposite direction as the blood flows through the valve (Fig. 6.130). This test should not be performed if a DVT is suspected.
Hospital tests Plethysmography. A range of methods can be used - impedance or air plethysmography, phleborheoplethysmography and mercury straingauge plethysmography. These instruments can be used to diagnose thrombotic obstruction of major proximal veins of the extremities. They are not useful for detecting calf vein thrombosis. Venous angiography. A radio-opaque dye is injected into the affected vein to show valvular incompetence and the presence of an obstruction. Duplex ultrasound. Duplex can be used to ascertain the long saphenous vein suitability for
110
SYSTEMS EXAMINATION
femoral bypass grafting as well as determining the presence of a thrombus.
system, such as obstruction or damage due to r~diotherapy, malignant disease, surgery (Case history 6.4), pregnancy ('white leg') or certain tropical infections (filariasis).
LYMPHATIC DRAINAGE As previously described, the lymphatic vessels play an important part in draining tissue fluid back, via the thoracic duct, to the heart. If lymphatic drainage is adversely affected, oedema (lymphoedema) results. Lymphoedema can be congenital, where it is classified as primary, or acquired, where it is classified as secondary lymphoedema. The causes of primary and secondary lymphoedema are outlined in Table 6.8.
Medical history and symptoms A history of permanent oedema, usually confined to the lower limbs, suggests primary lymphoedema, especially if there is a family history of the disease as one form is an autosomal dominant condition (Milroy's disease). Onset is either early in life (lymphoedema praecox) or after the age of about 35 years (lymphoedema tarda). It affects females more than males. Unlike venous oedema, once it is organised, it will not be alleviated by leg elevation. In contrast, secondary lymphoedema will arise as a result of some trauma to the lymphatic
Table 6.8 Causes of lymphoedema Type
Cause
Primary (congenital)
Milroy's disease Idiopathic
Secondary (acquired)
Intrinsic: malignant neoplasia radiotherapy surgical excision of lymph nodes filariasis infection pregnancy Extrinsic: trauma plaster cast
Observation Oedema In primary lymphoedema the oedema begins as a soft, pitting form but becomes harder and nonpitting with time. The condition can be unilateral or .t'ilateral. Secondary lymphoedema is usually umlateral and considerable fibrosis may occur (Case history 6.4, Table 6.8).
Tissue viability The tissue fluid stagnation will interfere with diffusion of gases and nutrients and removal of waste products and, as a result, impair tissue viability. It may be associated with troublesome cellulitis and usually leads to a thickening and scaling of the skin, which can lead to an 'elephantiasis-like' appearance: an oedematous leg with skin that resembles elephant skin.
Case history 6.4 A40-year-old male Caucasian attended clinic complaining of difficulty in undertaking routine foot care of the left foot. An assessment of the vascular status revealed ~hat the left leg was considerably largerthan the nght and the skin was thickened, dry a~d coarse. Th~ nails on the left were very thickened, distorted and discoloured. Examination of the left leg showed the presence of non-pitting oedema. The patientsaid the left leg had become very swollen and theskin thickened and dry after an operation on his groin. The past medical history revealedthat the patient had ~ad testicular cancer. This had been treated by surgical removal of the testicles and radiotherapy. His problems with the left leg had resulted afterthe course of radiotherapy. Adiagnosis of secondary lymphoedema was made. It is likely that the radiotherapy damaged the left-side inguinal lymph nodes and as a result lymphatic drainage of the left leg was adversely affected, resulting in lymphoedema.
VASCULAR ASSESSMENT
Lymphangitis and lymphadenitis
As the majority of tissue fluid normally drains into the lymphatic system, it follows that any infection present in the tissues, as indicated by the presence of cellulitis, will also drain into the lymph vessels unless dealt with by the inflammatory response at the site of infection. The presence of infection in the lymphatic vessels causes local inflammation, seen as red streaks following the course of the vessel; it is called lymphangitis. Should the infection reach the lymph nodes/ glands into which the lymph vessels drain, they will become tender and swollen (lymphadenitis). If not overcome by the body's natural defences or by appropriate antibiosis, the infection will enter the bloodstream (bacteraemia) and finally cause widespread systemic infection (septicaemia /blood poisoning). Yellow nail syndrome
The nail appears yellow in colour, thickened but smooth and there is an increase in lateral curvature. The rate of growth of the nail is reduced. The condition is associated with chronic lymphoedema.
Clinical tests It is not usual to carry out any clinical tests for lymphoedema apart from those which will distinguish it from other types of oedema, such as whether it is pitting or non-pitting.
Hospital tests Angiography for lymphatic vessels (lymphangiography) can be carried out in the same
111
manner as for venography. In primary lymphoedema X-rays may show hypoplasia of the lymphatic system, with the lymphatic channels appearing scanty and spidery.
SUMMARY This chapter has outlined an assessment process from which practitioners can arrive at a diagnosis of the vascular status of a patient. Case studies have been included to illustrate the effects of vascular problems. The information gained from the vascular assessment can be used to make a diagnosis and draw up an effective treatment plan. While many different pathologies can affect the cardiovascular system, there are five important signs which should always alert the practitioner to further investigation: • • • • •
absence of pedal pulses ABPI <0.9 intermittent claudication oedema a difference in temperature between the two lower limbs of 2°C or more.
It is important to establish if tissue perfusion falls within an acceptable range in relation to the patient's age. If it does, as long as no other problems exist, the patient can receive the same treatment as for any other non-risk patient. If vascular problems are present or there is a distinct possibility they will occur in the future, then it is important to give prophylactic advice and treatment. Choice of treatment, e.g. surgery, will be affected by the presence of vascular problems, as wound healing will be impaired and the patient is at greater risk of developing infections.
REFERENCES Ameli F M, Stein M, Provan J L, Aro L, Prosser R, St Louis E L 1989 Comparison between transcutaneous oximetry and ankle-brachial pressure ratio in predicting run off and outcome in patients who undergo aortofemoral bypass. Canadian Journal of Surgery 32: 428--432 Banga J D 1995 Lower extremity arterial disease in diabetes mellitus. Journal of British Podiatric Medicine 50: 68-72
Blackwell S 2001 Common anemias - What lies behind? Clinical Reviews 11: 53-62 Coull A 1988 Making sense of pulse oximetry. Nursing Times 32: 42--43 Davies C S 1992 A comparative investigation of anklebrachial pressure indices within an age variable population. British Journal of Podiatric Medicine 48: 21-24
112
SYSTEMS EXAMINATION
Davies A H, Horrocks M 1992 Vascular assessment and the ischaemic foot. Foot 2: 1-6 Faris I 1991 The management of the diabetic foot, 2nd edn. Churchill Livingstone, Edinburgh, p 150 Ganong W F 1991 Review of medical physiology, 15th edn. Lange, London, p 510 Hecht H S, Superko H R 2001 Electron beam tomography (EBT) may improve diagnosis of subclinical CAD in females. Journal of the American College of Cardiology 37: 1506-1511 Howell M A, Colgan M P, Seeger R W, Ramsay D E, Sumner D S 1989 Relationship of severity of lower limb peripheral vascular disease to mortality and morbidity: a six year follow-up study. Journal of Vascular Surgery 9: 691-696, discussion 697 Huntleigh Diagnostics 1999 Library of sounds-support booklet for audio cassette. Huntleigh Diagnostics, Cardiff, pp 5-21 Insall R L, Davies R L Prout W G 1989 Significance of the Buerger's test in the assessment of lower limb ischaemia. Journal of the Royal Society of Medicine 82: 729-731 Kapoor A S, Singh B N 1993a Prognosis and risk assessment in cardiovascular disease. Churchill Livingstone, New York, p 131 Kapoor A S, Singh B N 1993b Prognosis and risk assessment in cardiovascular disease. Churchill Livingstone, New York, pp 130-131, 145 Kapoor A S, Singh B N 1993c Prognosis and risk assessment in cardiovascular disease. Churchill Livingstone, New York, pp 4, 11,423 Khachemoune A, Sahu M, Phillips T J 2001 Diagnostic dilemmas. Wounds 13: 2-4 Kumar P L Clark M L 1990a Clinical medicine. A textbook for medical students and doctors, 2nd edn. Bailliere Tindall, London, p 571
Kumar P L Clark M L 1990b Clinical medicine. A textbook for medical students and doctors, 2nd edn. Bailliere Tindall, London, p 516 Kumar P L Clark M L 1990c Clinical medicine. A textbook for medical students and doctors, 2nd edn. Bailliere Tindall, London, pp 539-540 Kumar P L Clark M L 1990d Clinical medicine. A textbook for medical students and doctors, 2nd edn. Bailliere Tindall, London, p 538 Lainge S P, Greenhalgh R M 1980 Standard exercise test to assess peripheral arterial disease. British Medical Journal 280: 13-16 Lowe G D 0 (ed) 1993 Critical limb ischaemia - a slide lecture kit. Schering Health Care/Professional Postgraduate Services Europe Ltd, Worthing Mercer KG, Berridge D C 2000 Peripheral vascular disease and vascular reconstruction. In: Boulton A J M, Connor H, Cavannagh P R (eds) The foot in diabetes, 3rd edn. J Wiley, Chichester, p 220 Murphie P 2001a Macrovasular disease aetiology and diabetic foot ulceration. Journal of Wound Care 10: 103-107 Murphie P 200lb Microvascular disease aetiology in diabetic foot ulceration. Journal of Wound Care 10: 159-162 Nicholson M L Byrne R L, Steele G A, Callum K G 1993 Predictive value of bruits and Doppler pressure measurements in detecting lower limb arterial stenosis. European Journal of Vascular Surgery 7: 59-62 Smith F C T, Shearman C P, Simms M H, Gwynn B R 1994 Falsely elevated ankle pressures in severe leg ischaemia: the pole test - an alternative approach. European Journal of Vascular Surgery 8: 408-412
FURTHER READING
Berkow R (ed) 2000 The Merck manual. Merck, Sharp and Dohme Research Laboratories, New Jersey Berne R M, Levy M N 1992 Cardiovascular physiology, 6th edn. Mosby Year Book, St Louis, MO Vander A, Sherman L Luciano D 2000 Human physiology the mechanisms of body function, international
edition, 8th edn. McGraw-Hill, Boston Walker W E 1991 A colour atlas of peripheral vascular disease. Wolfe Medical, London Yao S T 1970 Haemodynamic studies in peripheral arterial disease. British Journal of Surgery 57: 761-766
CHAPTER CONTENTS Why undertake an assessment of the patient's neurological status? 113
Neurological assessment
OVERVIEW OF THE HISTOLOGY, ORGANISATION AND FUNCTION OF THE NERVOUS SYSTEM 115
J. McLeod Roberts
Histology 115 Glial cells 115 Neurones 115 Organisation 116 Anatomical classification 116 Functional classification 122 Function 124 The nerve impulse 124 Sensory pathways 126 Motor pathways 129 Cerebellum 130 Basal ganglia 130 Reflexes 130 Reflex arcs 131 Coordination and posture
133
THE NEUROLOGICAL ASSESSMENT
134
General overview of neurological function History 135 Observation 136
135
Assessment of the level of consciousness History 136 Observation 137 Clinical tests 137 Hospital tests 137 Laboraory tests 138
136
Assessment of lower limb sensory function 138 History 139 Clinical tests 139 Hospital tests 144 Assessment of lower limb motor function Upper motor neurone lesions 145 Lower motor neurone lesions 146
144
Assessment of coordination/proprioception function 150 Observation 150 Clinical tests 151 Assessment of autonomic function Observation 153 Clinical tests 153 Summary
154
153
There are many conditions affecting the nervous system which modify lower limb function (Table 7.1). The purpose of this chapter is to enable the practitioner to detect the presence of these conditions. The chapter begins with an outline of the histology, organisation and function of the nervous system. Reflexes are dealt with as a separate topic as they form the basis of so much neurological behaviour. It is not possible to discuss the nervous system without also making some reference to the muscular system: since muscles are the effector organs for much nervous activity, neurological deficits are often recognised by their characteristic effects on muscle. Similarly, muscular disease may show similar characteristics to those of nervous disorders. The second part of this chapter is concerned with a detailed description of the assessment of each part of the neuromuscular system and, for the purposes of this chapter, the descriptive term 'neurological' is also taken to imply 'neuromuscular' wherever appropriate.
Why undertake an assessment of the patient's neurological status? It is important to undertake an assessment of the neurological status in order to identify whether the patient has an intact and normally functioning neurological system. The purpose of the assessment is to:
• establish which, if any, part of the nervous system is functioning abnormally 113
114
SYSTEMS EXAMINATION
Table 7.1
Neurological conditions that may affect the lower limb
Condition
Description
Cerebral vascular accident (CVA) (stroke)
Due to haemorrhage, embolus or thrombosis of the cerebral arteries
Parkinsonism
Degeneration of dopaminergic receptors. Usually idiopathic but can be drug induced
Friedreich's ataxia
One of a group of hereditary syndromes affecting the cerebellum. Inheritance is autosomal recessive. Onset in childhood, death usual around 40 years
Multiple sclerosis
Patchy demyelination of the CNS. Shows relapses and remissions. Onset 20+
Poliomyelitis
Virus that affects lower motor neurones (LMNs).
Syringomyelia
Progressive destruction of the spinal cord due to blockage of central canal, e.g. tumour
Tabes dorsal
Occurs with tertiary stage syphilis
Spina bifida
Defective closure of vertebral column. Congenital
Motor neurone disease
Degeneration of both upper motor neurones (UMNs) and LMNs. No sensory loss. Onset usually between 40 and 60 years. Death usually due to respiratory infection. Idiopathic
Subacute combined degeneration of the spinal cord
Due to lack of vitamin B12 . Usually seen in pernicious anaemia. Affects both sensory and motor tracts in the spinal cord. See UMN signs, sensory and proprioceptive deficit. Reversible if detected in time
Charcot-Marie-Tooth disease/ peroneal muscle atrophy/hereditary motor-sensory neuropathy
Affects peroneal nerve, predominantly motor with variable sensory deficit. Commonest inherited neuropathy. Usually autosomal dominant. Onset in teens, slowly worsens
Guillain-Barre syndrome
Post-viral autoimmune response, rapid onset, potentially fatal from respiratory failure. Predominantly motor effects, with muscle weakness and paralysis, but some sensory loss; 80% of patients show full recovery. Also chronic relapsing form
Neurofibromatosis
Autosomal dominant condition that leads to tumours of nerves and compression of spinal cord
Peripheral neuropathy
Occurs due to a variety of causes, e.g. alcoholism, injury, diabetes mellitus
Myasthenia gravis
Autoimmune disease that affects the neuromuscular junction and leads to severe fatigue and weakness/paralysis
Myopathies
Range of relatively rare diseases affecting muscle only. May be inherited or acquired. Symptoms similar to LMN diseases but no fasciculation
• identify the extent of dysfunction • where possible, arrive at a specific diagnosis • draw up a treatment plan which takes account of the above information. It is important to establish which part or parts of the nervous system are affected. For example, an ataxic (uncoordinated) gait may be due to a disorder of the cerebellum or a lack of proprioceptive information. The practitioner may be in a position to identify early changes in neurological
function, e.g. initial clinical features associated with multiple sclerosis such as double vision, falling over, tingling sensations, and loss of function. If an appropriate treatment plan is to be drawn up, knowledge of the presence of any condition and its specific effects on the lower limb is essential. For example, sufferers of Cuillain-Barre syndrome are predisposed to foot ulcers and so the treatment plan should include preventative measures and a monitoring programme, as 10% of patients may show incomplete recovery.
NEUROLOGICAL ASSESSMENT
OVERVIEW OF THE HISTOLOGY, ORGANISATION AND FUNCTION OF THE NERVOUS SYSTEM
Pedicle
115
Blood vessel
HISTOLOGY There are two types of cell that make up the tissue of the nervous system: glial cells and neurones. A
B
C
D
Glial cells There are four types of glial cell (Fig. 7.1): • ependymal • oligodendrocytes (brain) and Schwarm cells (periphery) • astrocytes • microglial. Ependymal cells are involved in the secretion and absorption of cerebrospinal fluid (CSF), which acts as an interstitial fluid, bathing the cells of the brain and spinal cord. Oligodendrocytes in the brain and Schwarm cells in the periphery are responsible for the manufacture of a fatty (myelin) sheath around the axons of the neurones, which improves the speed of nerve conduction. They also playa role in the development and repair of nervous tissue, helping to guide the growing axons to their correct destinations. Astrocytes have a buffering function, ensuring that the K+ concentration of the CSF is constant. This is essential for the correct functioning of the neurones. These cells may also have a nutritive role, they are phagocytic and they take up certain neurotransmitters. Microglial cells are also phagocytic and remove debris. Since glial cells outnumber the neurones by a factor of at least 10 to 1, their sheer bulk means that they provide structural support, there being no connective tissue within the nervous tissue.
Neurones Despite being in the minority, a mere 10 12 in the brain, it is these cells which have the very special function of rapid communication, transmitting signals or nerve impulses from one
Figure 7.1 Neuroglia A. Fibrous astrocyte B. Ependymal cell
C. Oligodendrocyte D. Microglial cell.
neurone to the next, or to other excitable tissue such as muscle. Like other highly specialised cells, neurones lose the ability to mitose soon after birth and so once the cell body is destroyed, it cannot be replaced; damage results in permanent changes. A neurone consists of four main parts (Fig. 7.2): 1. Cell body. This contains the nucleus and other organelles and is the site of synthesis of chemicals (neurotransmitters) for the transmission of impulses. 2. Dendrites. These fine branches from the cell body are the chief receptive area for impulses from other neurones or for the reception of other stimuli. 3. Axon. This is the conducting portion and can be up to 1m in length. It conducts electrical impulses and is also involved in the transport of various substances to and from the cell body. It may be myelinated as shown but if less than Lpm in diameter it will be unmyelinated. 4. Presynaptic terminals. These are fine branches of the axon and are responsible for the release of neurotransmitters to enable the
116
SYSTEMS EXAMINATION
'.j'ti===:;:=== Neurofibrils Nissl bodies
.~
\ \ - - - Dendrites
Node of Ranvier - - - - ' l o . ",-\\\'ll'r----
Myelin sheath Nucleus of Schwann cell
Axon----~\
' - - - - Synaptic knob
-r--=------'''-----
Presynaptic terminal
impulse to pass from one neurone to the next or on to a muscle or gland. The gap or synapse between one neurone and the next is an area of physical discontinuity (Fig. 7.3).
- - - - - Presynaptic
*"--------
Anatomical classification Central nervous system (CNS)
This contains all the structures lying within the central axis of the body; the brain and spinal cord. It consists of neurones and glial cells.
Postsynaptic
II",,~\ ...1 ' - - - 7 9 - -
ORGANISATION The nervous system can be divided in a number of ways to identify its different parts, based on both anatomical and functional classifications (Fig. 7.4).
Figure 7.2 A single neurone (not to scale) illustrating the four parts: cell body, dendrites, axon, presynaptic terminals. Note that in the eNS some neurones may have no axons.
Presynaptic
)~::::~L__ Postsynaptic
Presynaptic
_::..JL----\.)/ ":;"....,4-""::_-
Postsynaptic
Presynaptic _~~#,---':~)I,y.:·· ':\'G??'" Postsynaptic ----II------,H
Figure 7.3 Diagram of synapses, identifying pre- and postsynaptic membranes (adapted from Vander et aI1990).
NEUROLOGICAL ASSESSMENT
<
117
BRAIN
CENTRAL NERVOUS (CNS) SYSTEM
SPINAL CORD
NERVOUS SYSTEM (NS)
<
AFFERENT (SENSORY)
SOMATIC NS
EFFERENT (MOTOR)
PERIPHERAL NERVOUS (PNS) SYSTEM
AFFERENT
AUTONOMIC NS
<SYMP <
EFFERENT PARASYMP
Figure 7. 4
Flow diagram of the organisation of the nervous system.
The brain can be divided into fore-, mid- and hindbrain and is covered by the three meninges and protected by the cranium (Fig. 7.5). The cerebral cortex (telencephalon) consists of two hemispheres (right and left), each of which is divided into four lobes by deep grooves or sulci. The four lobes are frontal, parietal, temporal and occipital. The cortex is highly convoluted, which increases its surface area and therefore the number of neurones it contains. It overshadows other structures in the forebrain such as the basal ganglia and thalamus (diencephalon). An interconnected collection of cortical and subcortical structures - including parts of the frontal and Table 7.2
Areas of the brain and their function
Area Forebrain
Midbrain Hindbrain
temporal lobes, thalamus and hypothalamus form the limbic system, the output of which is coordinated by the hypothalamus. The cerebellum consists of two hemispheres which are primarily composed of the anterior and posterior lobes. These are phylogenetically younger than the flocculonodular lobe and the midline structure called the vermis. The brain stem consists of the medulla, pons and midbrain. It contains a diffuse network of neurones called the reticular formation and discrete clusters of neurones called nuclei. The parts of the brain and their main functions are listed in Table 7.2.
Function Cerebral cortex
Frontal lobe: abstract thought, conscious action, speech Parietal lobe: general senses, verbal understanding Temporal lobe: hearing, taste, smell, emotions Occipital lobe: vision
Diencephalon
Thalamus: sensory relay station Hypothalamus: emotions, endocrine system, ANS Limbic system: motivation and emotions Basal ganglia: movement
Corpora quadrigemina
Superior colliculi: visual orientation Inferior colliculi: auditory orientation
Pons
Modification of respiration
Cerebellum
Modification of movement
Medulla oblongata
Vital control centres
118
SYSTEMS EXAMINATION
Cerebrum Diencephalon
-t'rt'W-{-- Cerebellum
aP=---I---
Spinal cord
A
Somatosensory cortex
---',,---- Parietal lobe ~T--
Frontal lobe
Taste cortex
'-+--+-_ Auditory cortex
---f--jf;,..+-"..
'...' \''8\--t-- Occipital lobe ~.,~';iIII"""''---
Visual cortex
B Figure 7.5
The brain
A. Anatomy of the brain
B. Position of the lobes and cortex (adapted from Vander et al 1998).
The spinal cord is surrounded by the 32 vertebrae of the spinal column; the cell bodies of the neurones form the so-called 'grey matter'
and their axons form the 'white matter' because of the presence of myelin. Cerebrospinal fluid (CSF) circulates through and over the brain and
NEUROLOGICAL ASSESSMENT
spinal cord. During development a difference in growth rates between the spinal cord and the surrounding vertebrae means that the spinal cord ends at the upper border of the second lumbar vertebra (Fig. 7.6). The dura mater and
10
A""l--=---Cl ~L.J 1 C2
tJ
04
D CJ /l
~
:R
=-'
02 03
05 06
C)7
119
the subarachnoid space, with eSF, continue to the level of the second sacral vertebra, so that lumbar punctures can be performed at the level of L3 or L4 to withdraw a sample of eSF without damaging the spinal cord.
C3 C4
C5
C6
C7
~~:rif=~~""'M-_T--- Lumbar plexus L1-4
l--+H-+---+---- Femoral t;tS1--t-'r-----'\--- Sacral plexus L4, 5; S1-3
Hamstring nerve --j"----t----l--T-+t-'
L3 Sciatic - - - ' - - - - + - t f l L4
1 + - - - - - - Common peroneal
L5
1 + - - - - - - - Superficial peroneal Tibial - - - - - - - f - - l I H I
I f f i H + - - - - - - - Saphenous
A ~-
Deep peroneal
B
Figure 7.6 The spinal cord A. Relationship of vertebrae to spinal cord segments (reproduced from Matthews & Arnold 1991, with permission) B. Organisation of the lumbar and sacral plexi and innervation of the lower limb (adapted from McClintic 1980).
120
SYSTEMS EXAMINATION
Peripheral nervous system (PNS)
pairs of spinal nerves. The spinal nerves emerge from the spinal cord as two roots, a dorsal (posterior) and a ventral (anterior) root, which then join to form the peripheral mixed spinal nerve (Fig. 7.7), which emerges between two adjacent vertebrae. The dorsal root contains the cell bodies of afferent fibres in a swelling called the dorsal root ganglion. The central process of each afferent neurone travels into the area of grey matter of the spinal cord called the dorsal horn. The ventral root contains mainly efferent fibres, the cell bodies of which lie within the ventral and lateral horns of the spinal grey matter.
The PNS comprises those nerves that lie outside the spinal cord and brain, which can be subdivided into: • afferent nerve fibres, which carry impulses towards the CNS from receptors such as warmth receptors • efferent nerve fibres, which carry impulses away from the CNS to effectors such as the leg muscles or sweat glands. The nerve processes form 12 pairs of cranial nerves originating from the brain stem and 31
A Internuncial neurones Dorsal root
Peripheral receptor Smooth muscle or gland Skeletal muscle ~----,Ht--
Grey ramus White ramus
rn/
Ventral root
VI"e",' orqan
B
/~
~ , ....•...
!----
Sympathetic ganglion
.~.,
Visceral receptor
Figure 7.7 A. Transverse section through the spinal cord showing mixed spinal nerve roots: (1) the paired mixed spinal nerves; (2) dorsal (posterior) root; (3) ventral (anterior) root (4) central grey matter; (5) dorsal horn; (6) ventral horn; (7) central canal; (8) surrounding white matter; and (9) dorsal root ganglion B. Connection between sensory and motor neurone to the spinal cord (adapted from McClintic 1980).
NEUROLOGICAL ASSESSMENT
The spinal nerves are mixed as they contain both afferent and efferent fibres, from both the somatic and the autonomic nervous system (see below). This is why damage to a spinal nerve may affect autonomic function (e.g. loss of bladder control) as well as motor and sensory function, depending upon the site of damage. Again, the unequal growth rates of spinal cord and vertebral column mean that the spinal nerves from L2 onwards have to travel some way posteriorly before emerging at the appropriate level between the vertebrae. This results in the formation of the 'cauda equina'. A dermatome is defined as an area of skin supplied by a single nerve's dorsal root. It also implies that muscles are innervated in a similar segmental pattern. Dermatomes overlap each other by up to 30%, so if a spinal nerve is damaged there will not be a total loss of sensation in that area as adjacent dermatomes will respond to stimuli. The dermatomes of the lower limb are outlined in Figure 7.8.
121
L1 L1
L2
L2
r---L5 L5
Muscle
Muscle is divided histologically into three main types (Table 7.3):
Front
Back
• skeletal • cardiac • smooth.
Figure 7.8 The lower limb sensory dermatomes and their nerve roots (adapted from Epstein et al 1992).
In general, skeletal muscle is structurally the most highly organised, smooth muscle has the simplest structure and cardiac muscle lies some-
where in between. All three types of muscle depend on the binding of calcium ions to calcium-binding proteins to initiate contraction.
Table 7.3
Classification of muscular tissue
Features
Skeletal
Cardiac
Smooth
Structure
Elongated fibres Multi-nucleated syncytium Striations visible
Branched fibres Single nucleus per cell Striations visible
Spindle-shaped fibres Single nucleus per cell No striations visible
Innervation
Somatic nerves
Autonomic nerves
Autonomic nerves
Function
Moves bones Functions as part of a motor unit
Pumps blood Forms a functional unit
Moves vessels, organs and glands Forms functional sheets
Cannot contract without nerve impulse
Has myogenicity
Myogenicity in some smooth muscles
Conscious control
Unconscious control
Unconscious control
122
SYSTEMS EXAMINATION
This shortening involves the formation of crossbridges and sliding of actin and myosin myofilaments over one another.
Functional classification While it is possible to divide the nervous system into areas according to function, it has to be remembered that the nervous system acts as a coordinated whole, so that many areas of the somatic and autonomic nervous systems will work together. This is best illustrated by the total response to an intensely painful stimulus, where the painful stimuli are fed not only into the sensory cortex but also to the hypothalamus and limbic system, and the response is a product of action by the somatic motor, autonomic and endocrine systems on a range of muscles and glands. Somatic nervous system
This includes all parts of the nervous system that deal with the conscious perception of stimuli and conscious action, including the sensorimotor or so-called conscious cortex. The afferent nerves can also be called sensory nerves and the efferent nerves can be called motor nerves. The receptors detect changes in the external environment and the effectors bring about movement of the skeleton. Autonomic nervous system (ANS)
This is the part of the nervous system that deals with the internal organs. The parts of the brain primarily involved with the autonomic system are the hypothalamus and the limbic system. The terms sensory and motor are not used here, as these terms imply consciousness, and much information coming from the viscera, such as partial pressure of oxygen in arterial blood, does not reach consciousness; likewise, the movements of the viscera are rarely voluntary movements. The afferent neurones are similar in arrangement to those of the somatic system, with cell bodies in the dorsal root ganglia, although the receptors are situated in internal organs such
as the baroreceptors of the carotid sinus. The efferent branches of the ANS differ from those in the somatic system in that there are two neurones in the pathway. The cell body of the first neurone is in the eNS but those of the second are found in the autonomic ganglia outside the eNS. This divides the efferent neurones into pre- and postganglionic neurones. This efferent outflow can be further divided into the sympathetic and parasympathetic systems (Fig. 7.9). The effector organs for both systems are composed of smooth or cardiac muscle. Parasympathetic nervous system. This is the efferent part of the autonomic nervous system which restores the 'status quo' and allows emptying actions. The cell bodies of the preganglionic neurones are situated in the brain stem and sacral region of the spinal cord (craniosacral outflow). The postganglionic cell bodies are found in ganglia close to or within the effector organ being innervated, so that the majority of the efferent pathway is preganglionic. The neurotransmitter released at both the pre- and postganglionic endings is called acetylcholine. Sympathetic nervous system. This is the efferent branch of the autonomic nervous system which prepares the body for action: the fight or flight response. The cell bodies of the preganglionic neurones are found in the lumbar and thoracic regions of the spinal cord and the sympathetic ganglia form a chain alongside the spinal cord, so that the majority of the efferent pathway is postganglionic (see Fig. 7.7B). The neurotransmitter released at the preganglionic endings is again acetylcholine, but the postganglionic endings mostly release noradrenaline (norepinephrine). Where an effector organ receives dual innervation, the two branches usually act antagonistically, in a push-pull or accelerator-brake fashion, to regulate the activity of the effector organ. For example, the vagus nerve (tenth cranial nerve) slows the heart rate down and the sympathetic nerve speeds it up. However, the parasympathetic nerves do not innervate structures outside the central axis apart from blood vessels of the pelvic region. All other peripheral structures, skin and blood vessels, are innervated by the
NEUROLOGICAL ASSESSMENT
Preganglionic fibres Postganglionic fibres
Eye
Pons Medulla
,."
~'
,."
•
,." -- .... ----------
Olfactory glands
Salivary glands
Adrenal glands
Spleen
Kidney
Small intestine
Colon
Parasympathetic
Figure 7.9
Autonomic outflow (adapted fro m Vander et al 1998).
Sympathetic
123
124
SYSTEMS EXAMINATION
sympathetic system. Sympathetic activity causes peripheral vasoconstriction and a reduction in this activity or 'tone' causes vasodilation.
FUNCTION As with all systems within the body, the prime function of the nervous system is to ensure that the internal environment which bathes the cells is maintained within acceptable limits (homeostasis). The particular role of the nervous system is to ensure that the collection of cells and tissues that constitute our bodies can act as an organised whole. This can only be achieved if the cells can communicate with one another. The nervous system has evolved as the system of rapid communication, usually producing short-term effects. It evolved with, and works alongside, the generally slower endocrine system, which tends to have long-term effects.
The nerve impulse Neurones use two types of signal to achieve intercellular communication - graded and action potentials. Both types of signals are dependent upon the movement of ions across the cell membrane and through protein ion channels, but they also show many differences. Action potential
This is used by the neurone to transmit an impulse over long distances along its fine cytoplasmic processes, the dendrites and axons (see Fig. 7.2). The action potential is initiated by a voltage change which causes sodium channels to open, allowing the influx of sodium. The entry of these positively charged ions causes a reversal of the resting membrane potential or a 'depolarisation'. Provided the initial voltage change is large enough and of sufficient duration, a threshold value of depolarisation will be reached and a positive feedback cycle will be established, causing further opening of sodium channels and depolarisation. The magnitude of this depolarisation will be dependent on the number of ion channels present in the plasma membrane and is
therefore fixed for a particular neurone. Provided the threshold is reached, the resulting action potential will always have the same value for that neurone. This is known as the 'all or nothing law'. Since the ion channels are operated by a voltage change, they are described as voltagegated channels. The depolarisation is reversed when the sodium channels close and potassium channels open, allowing an efflux of potassium ions. This renders the interior of the neurone more and more negative, and the membrane is now 'repolarised'. At the same time the sodium pump, present in all plasma membranes, actively pumps out the sodium which has recently entered and claws back the escaped potassium. Due to a time lag in the closing of the potassium channels, the inside of the neurone actually becomes briefly more negative than when at rest, and this phase is described as 'hyperpolarisation' (Fig. 7.10). The opening and closing of the ion channels is triggered by the initial voltage change, but because this opening and closing operates at different rates, the ions move in the sequence just mV
40
2
20 0 3
-20 -40
-60
5
-80
Figure 7.10 Diagrammatic representation of an action potential. 1 = Na+ enters axon; 2 = Na+ channels close, K+ leaves; 3 = Na+/K+ pump begins; 4 = K+ channels close; 5 = resting potential restored.
NEUROLOGICAL ASSESSMENT
described. Finally, the distribution of ions is restored to their pre-action-potential level and the membrane is at resting potential once more. All this activity is ultimately dependent upon energy being expended by the sodium/potassium ATPase (adenosine triphosphatase) pump: hence the term 'action potential'. Due to the establishment of local current flow, the initial depolarisation triggers an identical action potential at adjacent sites and this is propagated along the axon without any attenuation of the impulse. If the axon is unmyelinated, this sequence of events will be repeated at every point along the axon, spreading out in both directions away from the initial stimulus. The presence of myelin speeds up the passage of the impulse, since it enables the local current to spread further, up to 1 mm along the axon, before another action potential needs to be generated. Hence, the sodium channels need only be situated at 1 mm intervals, at the so-called 'nodes of Ranvier' with a myelin coat in between. Since local current flow is faster than the generation of an action potential, the impulse appears to jump or leap from node to node: hence the term 'saltatory conduction' from the Latin word saltare meaning 'to leap'. In multiple sclerosis there is a loss of the myelin coat and the nerve impulse is adversely affected, leading to the clinical features associated with this condition. Graded potential
When the action potential reaches the terminals of the neurone there has to be some mechanism by which the impulse can cross the synaptic gap, reach the next neurone in the pathway and generate an action potential in this neurone. This is achieved by means of release of a chemical or 'neurotransmitter' from the presynaptic terminals, which diffuses across the gap and combines with receptors on the postsynaptic membrane (see Fig. 7.3). The postsynaptic membrane is usually the dendrite of the next neurone, but can be an axon or the cell body itself. The release of the neurotransmitter from the presynaptic membrane is triggered by the arrival of the action potential, which opens calcium
125
channels in the plasma membrane. Influx of calcium causes the movement and exocytosis of vesicles laden with neurotransmitter. The latter is referred to as the first messenger. The consequence of combination of the neurotransmitter with postsynaptic receptors is a conformational change in proteins of the plasma membrane, resulting either in a direct effect on proteins to open or close ion channels or, much more commonly, in activation of an enzyme such as adenyl cyclase. This catalyses the production of cyclic AMP (adenosine monophosphate) from ATP (adenosine triphosphate). Cyclic AMP acts as a second messenger, triggering a cascade of internal events that finally results in the opening of ion channels, allowing depolarisation of the postsynaptic membrane, the so-called graded potential. Since the ion channels are opened by chemicals they are called chemically-gated channels. In parkinsonism there is a loss of the neurotransmitter dopamine, and with myasthenia gravis there is a loss of cholinergic receptors on the skeletal muscle end-plate; both these conditions adversely affect the normal functioning of the graded potential. Graded potentials rapidly dissipate and so can only travel over very small distances. Since they are small, they must summate to produce an action potential. Summation can be spatial (convergence) or temporal. This is initiated within a short distance on the postsynaptic membrane. Provided the summation is adequate, the summated graded potentials will initiate an action potential at a specific site on the nerve fibre where there are most sodium channels and the threshold is lowest. On most neurones this area is where the axon leaves the cell body, the axon hillock (see Fig. 7.2). Synapses slow down the passage of impulses due to the time taken for the neurotransmitter to be released, but this disadvantage is more than outweighed by the variability or plasticity which synapses confer on the system. They play an essential role in memory and learning, since frequent use of a particular pathway facilitates the passage of an impulse across the synapses used, in preference to others. Initially this is a chemical change, which may involve a facilitator such as nitric oxide, but later a physical increase occurs
126
SYSTEMS EXAMINATION
Table 7.4
Differences between action and graded
Action potentials
Graded potentials
Voltage-gated ion channels
Chemically/mechanically/lightgated ion channels
Threshold must be reached before an action potential is generated
No threshold, all triggers will generate graded potentials
Fixed magnitude (all or nothing)
Magnitude proportional to size of trigger
Large potentials
Small potentials
Do not summate
Summate
Do not attenuate
Rapidly attenuate
Used for long-distance signalling
Used for local signals
in the surface area and complexity of the synaptic membranes. They are also responsible for converting the pathways into one-way systems, essential if chaos is not to reign. Synapses are not the only site for graded potentials. They also occur at receptors where the ion channels may be triggered by mechanical or light changes as well as chemicals. The differences between action and graded potentials are summarised in Table 7.4.
Sensory pathways The various changes in the internal and external environments are detected by receptors. Receptors may be found within specialised organs, such as the rods and cones of the eye, or they may be distributed throughout the body, such as the pain receptors of the skin and gut. The first type give rise to the special senses of sight, hearing, balance, taste and smell, whereas the second type give rise to the general senses of
Table 7.5
pressure, touch, temperature, pain and position sense, the so-called somatic receptors (Table 7.5). Again, the use of the word 'sense' implies awareness of the stimulus, i.e. it reaches the conscious cortex. Those receptors situated in the skin can also be referred to as exteroceptors. There are also stimuli which do not usually reach consciousness but go to different areas of the brain; these originate within the internal organs and are called interoceptors. Examples of these are the baroreceptors in the aorta, which monitor changes in blood pressure, and the osmoreceptors in the hypothalamus, which monitor the osmolarity of the extracellular fluid. Receptors in the muscles, tendons and joints that register position sense, tension and degree of stretch are called proprioceptors. They send impulses both to the cerebellum, which is part of the unconscious brain, and to the part of the conscious brain called the somatosensory cortex. The area served by a sensory unit (afferent nerve, its branches and the attached receptors) is called the receptive field. Receptor fields may overlap and the density of receptors may vary in different regions of the body. The precision with which a stimulus can be located and differentiated depends on the size of the receptive field and the density. For example, fingers and thumbs are very good at detecting stimuli from the external environment because the receptive fields are small and dense. The peripheral afferent (sensory) pathway is the name given to the pathway from a receptor to the eNS. As explained earlier the cell body of the afferent neurone is usually situated along this pathway, near to, but not in, the spinal cord. The central process then travels into the spinal cord where it may synapse with one or more neurones
Classification of the somatic receptors
Category
Sense
Receptor
Mechanoreceptor Thermoreceptor Nociceptor Proprioceptor
Touch, pressure Warmth, cold Pain Position
Encapsulated and free nerve endings Free nerve endings Free nerve endings Encapsulated nerve endings
NEUROLOGICAL ASSESSMENT
in the dorsal horn or continue on its path up the spinal cord to the brain stern. The grey matter is divided into layers or laminae of Rexed and the neurones in the various layers differ in size and functions. Stimuli detected in the periphery will initially be conveyed by afferent neurones to the spinal cord, but if further integration and interpretation is to occur, the information must reach the appropriate part of the brain. The information travels to these higher centres in ascending tracts or columns of the white matter of the spinal cord (Fig. 7.11). All information from a particular receptor type, such as pressure, travels together in the same ascending tract. The ascending tract is joined, at each spinal segment on its upward journey, by neurones which are carrying information from pressure receptors in other dermatomes. The organisation continues in the brain, so that discrete areas of the cortex receive the information from the various parts of the body (Fig. 7.12). This is called somatotopic organisation. There are two main ascending systems (Budd 1984):
127
• the rapid, highly organised oligo- (few) synaptic pathways • the less well organised multisynaptic pathways. Most of the tracts are named according to their origin and destination: e.g. the lateral spinothalamic tract carrying pain information runs from the lateral region of the spinal cord up to the thalamus, an important sensory relay station in the brain. The spinocerebellar tracts do not reach consciousness but instead carry proprioceptive information to the ipsilateral lobes of the cerebellum, in the hindbrain. The oligosynaptic pathway consists of two tracts: • the dorsal (posterior) columns • the neospinothalamic tracts (part of the anterolateral tract). The multisynaptic pathways also travel via two ascending tracts. One of these tracts, the fasciculi proprii, runs as a central chain of neurones through the spinal cord and ascending reticular activating system (RAS) of the brain stern to the
J
fasciculus gracilis dorsal. , - (posterior) fasciculus cuneatus I co umns
dorsal spinocerebellar tract lateral corticospinal tract ventral spinocerebellar tract
anterolateral tract (neo-paleo-spinothalamic) ?
I
I
I
ascending brain stem tract I
(multineuronal)
I
ventral corticospinal tract I
descending
Figure 7.11
Transverse section of the spinal cord showing ascending and descending pathways (adapted from McClintic 1980).
128
SYSTEMS EXAMINATION
±
·.·' · 1( ,
:>".
.,
L
r )
A
B
Figure 7.12 Diagram illustrating the somatotopic organisation of (A) the motor and (B) the sensory cortex. The left half of the body is represented by the right hemisphere of the brain and the right half of the body by the left hemisphere (reproduced from Ross & Wilson 1990, with permission).
central areas of the thalamus, before projecting to the limbic system and the hypothalamus. These pathways do not cross and can be activated by more than one stimulus. The other multisynaptic pathway is the palaeospinothalamic tract, which follows the same course as the neospinothalamic tract until it reaches the brain stem, where it diverges, to make further synaptic connections with the RAS and central thalamus before travelling on to the limbic system. The information is interpreted in a less precise manner but with emotional overtones, such as the sensation of a deep, burning abdominal pain. The division into tracts of differing modalities is not hard and fast, however, since the nervous system demonstrates the phenomenon of redundancy, which means that if one tract is damaged another is usually able to take over the function, albeit in a slightly altered form. For example, impulses conveying information about touch travel in both the dorsal column and the ventrospinothalamic tract though the nature of the
information differs, as the dorsal column deals with detailed localisation of the touch sensation and the spinothalamic tract with gross tactile sensations. Some of the pathways, the neospinothalamic pain pathways in particular, carry information about a single type of stimulus. These are described as specific pathways, since they are interpreted as well-localised, precise sensations by the somatosensory cortex - e.g. the sharp sensation of a pinprick. The majority of these ascending tracts cross over to the opposite side at some stage, either in the spinal cord or in the brain stem, synapsing with contralateral areas of the thalamus before continuing to the conscious cortex. This arrangement explains why a stroke/ cerebrovascular accident (eVA) affecting a particular part of the sensory cortex produces numbness or paraesthesia in a specific part of the body on the opposite or contralateral side. Neurological damage to the spinal cord may produce numb-
NEUROLOGICAL ASSESSMENT
ness on either the contralateral side, if the site of damage is before the tracts cross, or the ipsilateral (same) side, if the site of damage occurs after the tracts have crossed.
Motor pathways Just as all conscious stimuli are interpreted in the cortex, so all conscious actions originate there. The whole area is known as the sensorimotor cortex; one part is called the primary motor cortex and initiates conscious action (Fig. 7.12). It too shows somatotopic organisation, so that damage to this region produces precise effects on particular actions on the contralateral side of the body. Close to this area is the premotor cortex, which is involved in the planning of actions. Since the actions produced by these neurones are the conscious movements of the body, the muscles involved will be skeletal and the neurones will be part of the somatic motor system. Neurones in the brain which are responsible for initiating the commands are called upper motor neurones (UMNs). They do not send impulses directly to the muscles but exert their influence via neurones in the ventral (anterior) horn of the spinal cord called lower motor neurones (LMNs). The latter send impulses to the skeletal muscles via their axons, which form the peripheral efferent pathways within spinal nerves. The descending pathways from brain to spinal cord can be divided into two main tracts: the corticospinal tract and the multineuronal (brain stem) tract (see Fig. 7.11). The corticospinal tract. This is a rapid pathway and is mainly responsible for the skilled movements of small, distal limb muscles such as those used in scalpel work. Most of the fibres cross over in the brain stem and descend in the white matter of the spinal cord as the lateral corticospinal tract. The uncrossed fibres descend as the ventral (anterior) corticospinal tract. At the appropriate level in the spinal cord they enter the ventral horn of the grey matter to synapse with a lower motor neurone. Because the corticospinal tract forms a rough pyramid shape as it passes through the brain stem, it is also called the pyramidal tract.
129
The multineuronal tract. This tract runs to lower motor neurones by a slower, more diffuse route, since it makes many more synaptic connections on the way, particularly in the descending reticular system and the nuclei of the brain stem. Although influenced by UMNs the tracts are only recognisable as separate pathways as they emerge from the brain stem to travel through the spinal cord as the vestibulospinal, tectospinal and reticulospinal tracts. The tracts enter the ventral horn of the grey matter to influence the appropriate lower motor neurone. These tracts do not form part of the pyramids in the medulla and so are also called the extra(outside) pyramidal pathways. They mainly influence the large, proximal limb muscles and the axial muscles of posture, and have a predominately inhibitory effect on the ventral horn cells. They are responsible for the antigravity reflexes, which keep our knees extended and head erect in order to maintain upright posture. The division of the descending tracts is not clear cut, as they also demonstrate redundancy, there being much overlap and interaction between the two. Other areas of the brain also have strong modifying influences, such as the cerebellum and clusters of neurones in the fore- and midbrain known collectively as the basal ganglia. The last stage in the production of a conscious action is the excitation of an LMN in the ventral (anterior) horn of the spinal cord and the passage of an impulse along its axon in the spinal nerve to the skeletal muscle. The LMN will be subject to influences from many neurones, not only from descending tracts but also from spinal neurones. As many as 10000-15000 synapses, both excitatory and inhibitory, can occur on one lower motor neurone. If the sum of these influences is excitatory, the LMN will be stimulated to discharge an impulse along its axon and the skeletal muscle will contract. This peripheral pathway from LMN to skeletal muscle is called the final common pathway and the entire pathway, including the neuromuscular junction and the 10-600 skeletal muscle fibres innervated by that nerve is called a motor unit (Fig. 7.13).
130
SYSTEMS EXAMINATION
skeletal muscle
a motor unit lower motor neurone
Figure 7.13
The final common pathway of a motor unit.
Basal ganglia At present the precise functions of the basal ganglia in movement are unknown, but they are thought to enable abstract thought (ideas) to be converted into voluntary action (Ganong 1991a). Like the cerebellum they function at an unconscious level and have no direct pathway to LMNs but influence the sensorimotor cortex and the descending reticular formation. Because the main action of the basal ganglia is on the descending extrapyramidal tracts, they have become known as the extrapyramidal system and conditions affecting them are referred to as extrapyramidal syndromes, e.g. parkinsonism.
REFLEXES Cerebellum The actions of the cerebellum are unconscious and are very important in postural reflexes. The cerebellum has no direct descending pathways to the spinal cord; instead it has a rich afferent input and sends modifying influences to the sensorimotor cortex, the reticular formation and the brain-stem nuclei. Thus, symptoms of cerebellar defects may be due to lesions in the ascending spinocerebellar tracts, in the cerebellum itself or in efferent pathways going to other parts of the brain. The cerebellum receives all information about position sense. The vestibular apparatus of the ear projects via the vestibular nuclei of the brain stem to the flocculonodular lobe. The spinocerebellar tracts carry proprioceptive information from muscles, tendons, joints and cutaneous pressure receptors which project to the vermis and anterior lobes. The cerebral cortex gives information about the actions decided upon and projects to the posterior lobes via pontine nuclei. The cerebellum integrates the information received from all these areas and compares it with the information on intended actions received from the cerebral cortex. It then sends modifying influences back to the motor cortex and brain stem, so that descending instructions to the LMNs can be altered where necessary.
Reflex actions are automatic responses to particular stimuli and form the basis of much of our behaviour, from the simple knee jerk to driving a car. They are also very important in posture, balance and gait. Reflexes can be inborn (inherited, innate, instinctive) or acquired (learned). Examples of the former are eye blink, pupil dilation/ constriction, change in heart rate, knee jerk (stretch) reflex, pain withdrawal and sweat secretion. Examples of the latter are swimming, walking, driving, debriding callus. They can involve any subdivisions of the nervous system and any type of effector organ. We may be aware of them or they may never reach consciousness. It is here that the close association between the nervous and endocrine systems is best illustrated, since both can contribute to the same reflex arc. For example, when the retina of the eye detects a threatening situation, this information will be carried by the optic nerve to the brain and one of the responses will be the release of the hormone adrenaline (epinephrine) from the adrenal medulla, to prepare the body for action. In all cases, the pathway allows the body to respond rapidly to a given stimulus. Generally, inborn reflexes produce stereotypic responses which are usually protective reflexes or those needed for posture and balance. Acquired reflexes are more complex, involving the conscious cortex and many different effectors, so that the response
NEUROLOGICAL ASSESSMENT
is more easily modified. Try standing upright and leaning backwards as far as you can. What happens to your arms and knees? Can you prevent their movement? Compare this with the ease with which you can change from a walking to a running gait.
Reflex arcs The pathway between detector and effector is called a reflex arc and always involves the CNS, though not necessarily the brain (Table 7.6). There are three reflexes that are of particular importance to the functioning of the lower limb: • pain withdrawal reflex • crossed extensor reflex • stretch reflex. Pain withdrawal reflex. Injured cells produce local chemical mediators, including prostaglandins, that sensitise the nociceptors to other mediators. Graded impulses, proportional to the damage done, are generated and trigger action potentials in the afferent pathways. The action potential travels to the CNS (in this case the spinal cord) via the afferent neurone and synapses within the grey matter of the dorsal horn, in either Rexed's laminae II and III (the substantia gelatinosa) or in laminae V. It is here that the pain gating mechanism is thought to take place. This mechanism was first described
Table 7.6
Essential elements of a reflex arc
1. A detector to detect the change (stimulus) in either the internal or external environment 2. Afferent neurones that send the information into the CNS along the afferent pathways 3. An integrating centre to match the appropriate response to the stimulus. This will be in the brain or spinal cord. Different parts of the CNS communicate with one another via ascending and descending pathways 4. Efferent neurones that carry instructions from the CNS via efferent pathways to the effectors (skeletal, smooth or cardiac muscle or gland) 5. An effector to carry out the necessary response
by Melzack & Wall in the 1960s to explain pain inhibition by such techniques as rubbing the painful area, although the precise nature of the gating mechanism is still not completely known. From here the impulse is transmitted to an LMN in the ventral horn of the spinal cord. Excitation of this neurone results in an action potential reaching the motor end-plate. The neurotransmitter acetylcholine is released and its combination with receptors in the muscle membrane results in a graded potential that will be transmitted to the interior of the muscle as an action potential and cause contraction of skeletal muscle fibres (Fig. 7.14). The number of fibres contracting depends on the number of muscle fibres innervated by that neurone, i.e. the size of the motor unit. Thus the limb suffer-
afferent neurone
----
skin
~ (receptor) internuncial neurones ---=~--n+r?::'" skeletal muscle (effector)
synapse Figure 7.14
131
efferent neurone
The reflex arc (reproduced from McClintic 1980, with permission).
132
SYSTEMS EXAMINATION
ing damage is removed from the deleterious cause. The presence of more than one synapse in the reflex arc means that the arc is described as polysynaptic. In addition to this reflex arc, the first-order neurones will synapse in the dorsal horn with neurones which transmit impulses up to neurones in the brain, via the ascending anterolateral tracts. However, the cortex is not needed for the withdrawal reflex to occur. Crossed extensor reflex. This is often superimposed on the pain withdrawal reflex and is a postural reflex, enabling an injured lower limb to be withdrawn while the remaining limb bears weight. In order for this to occur, many LMNs must be excited and their antagonists inhibited (Fig. 7.15). This ensures that the flexors of the injured limb contract while the extensors relax, whereas in the contralateral limb the flexors are
inhibited and the extensors contract to provide a rigid support. This reflex occurs not only when a lower limb is injured but at each step in walking, when one limb is in the swing phase and the other is weightbearing. Stretch reflex. This is a very important reflex for all motor activity, especially when new actions are being learnt. It can be demonstrated by the patellar and Achilles tendon reflexes and exists to supply the cerebellum with information about the state of contraction in muscle. The receptors are stretch receptors in specialised muscle fibres called intrafusal fibres. These receptors lie within swellings of the intrafusal fibres called muscle spindles. Whenever the ordinary muscle fibres (extrafusal fibres) are stretched, as when the patellar tendon is hit by the hammer, the receptors will generate graded
painful stimulus from foot
excitation of extensor
excitation of flexor __ contralateral limb
Figure 7.15
The crossed extensor reflex (reproduced from McClintic 1980,
w~th
permission).
NEUROLOGICAL ASSESSMENT
potentials. These will in turn trigger action potentials which will travel rapidly into the spinal cord, to synapse directly with the alpha LMNs. Efferent impulses will travel out to the extrafusal fibres, causing contraction of the muscle. The stretch receptors are of two types, one conveying information about the degree of stretch (static) and the other about the rate of change of stretch (dynamic). This information is sent along the spinocerebellar pathway to the cerebellum as part of the rich input that the cerebellum needs to be able to compile a precise 'picture' of what is happening in the muscles (Fig. 7.16). The reflex contraction of the muscle switches off the muscle spindle and deprives the cerebellum of information. This does not matter if the action being carried out by the muscle is a well-learned one, but if it is still being learned the cerebellum needs this information and can switch the spindle back on. This is achieved by a system of alpha-gamma coactivation, whereby small gamma LMNs are activated. These go to the poles of the muscle spindle and, by contracting the poles, the spindle continues to fire.
133
....I
to cerebellum
I I I I
COORDINATION AND POSTURE It is now possible to summarise the various parts of the nervous system which are involved in posture, balance, gait and coordination of motor activity (Table 7.7).
Table 7.7
Figure 7.16 The stretch reflex. Contraction of the extensor muscle causes stretch in the muscle spindle and increases the firing rate of action potentials. This information is conveyed to the spinal cord and results in inhibition of the extensor muscle's motor neurone and excitation of the flexor muscle's motor neurone (adapted from Vander et al 1998).
Role of CNS in posture, balance and coordination
Action
Site
Function
Motor coordination
Premotor cortex Sensorimotor cortex Basal ganglia Cerebellum Brain stem (extrapyramidal) (pyramidal)
Plans actions Initiates action Converts thought into action Modifies action. Compares actual and intended action, smooths action Modifies action Corrects position Skilled work
Posture and balance
Cerebellum
Rich input, miniprogrammes
Gait
All of above
134
SYSTEMS EXAMINATION
THE NEUROLOGICAL ASSESSMENT Once the organisation and function of the nervous system is understood, it is often possible to diagnose the site of a lesion by careful history taking, observation and simple tests. The causes of neurological disorders are many and can be classified as follows: • heredity, e.g. Huntington's chorea, peroneal muscular atrophy, Friedreich's ataxia, malignant hyperpyrexia • developmental defect, e.g. spina bifida, syringomyelia • trauma, e.g. severing of the spinal cord or a peripheral nerve, concussion • ischaemia, e.g. stroke, cerebral haemorrhage • compression, e.g. tumour of the cerebellum, Morton's neuroma, common peroneal nerve palsy • infection, e.g. HIV, [akob-Creutzfeldt disease, herpes zoster (shingles), Guillain-Barre syndrome, lepromatous neuropathy • autoimmune, e.g. myasthenia gravis, polymyositis, possibly multiple sclerosis • nutritional! metabolic, e.g. Korsakoff's psychosis, sub-acute combined degeneration of the spinal cord, diabetic neuropathy • iatrogenic, e.g. tight plaster cast causing nerve palsy, drug-induced myopathies (lithium, high-dose steroids, etc.)
Table 7.8
Classification of neuropathies
Type of neuropathy
Description
Mononeuropathy
Abnormality of a single nerve
Mononeuritis multiplex
Asymmetrical abnormality of several individual nerves
Radiculopathy
Abnormality of a nerve root
Polyneuropathy
Widespread, symmetrical abnormality of many nerves, usually characterised as sensory/motor/autonomic 'glove and stocking' distribution
• idiopathic, e.g. Parkinson's disease, motor neurone disease, non-familial Alzheimer's disease. The effects of any lesion in the nervous system will depend on the area involved. For example, occlusion of the posterior cerebral artery, which feeds the occipital lobe of the brain (striate cortex), may result in visual disturbances, occlusion of a cerebellar artery may result in ataxia, and occlusion of the vasa nervosum of a peripheral nerve may result in a 'glove and stocking' paraesthesia. Nerve function deficit is called neuropathy and is classified according to the numbers and types of nerves involved and the site of the lesion (Table 7.8). The assessment process involves a general overview of neurological function followed by assessment of: • • • • •
levels of consciousness sensory function motor function (to include muscles) posture and coordination autonomic function.
Many neurological conditions present with multiple signs and symptoms because more than one part of the nervous system is affected. It is important to bear this in mind when assessing each of the above parts in order that information from all the assessments can be put together to produce a definitive diagnosis. For example, multiple (disseminating) sclerosis is a progressive disease affecting the CNS where repeated patchy demyelination of nerve sheaths occurs, leading initially to temporary and later to permanent loss of function. The nerve axons most often affected are the optic nerves - the optic nerve is considered an outgrowth from the CNS rather than a peripheral nerve - the cerebellar nerves and those of the lower spinal cord, leading to blurring of vision (diplopia), unsteady gait, weakness in the lower limbs, lower limb sensory loss and/ or disturbances of micturition. Multiple sclerosis along with Parkinson's disease is the second most common disease to affect the CNS, after strokes (Wilkinson 1993a).
NEUROLOGICAL ASSESSMENT
GENERAL OVERVIEW OF NEUROLOGICAL FUNCTION History It is important to undertake a thorough medical
and social history (Ch. 5). In particular the following should be borne in mind. Presenting problem
Onset and duration may provide vital clues as to the cause of a problem. For example, Cuillain-Barre syndrome has a sudden, postviral onset. The type of pain and its distribution can help to establish whether the problem affects a nerve pathway or is referred pain from entrapment of a spinal nerve. The patients should be asked if their limbs feel weak or sluggish (paresis): a slow, progressive onset of muscular weakness suggests muscular dystrophy, whereas an acute onset suggests a demyelinating disease. The history of the problem and the type of onset may facilitate a diagnosis. For example, pain, numbness, a sensation of heaviness or a 'pins and needles' sensation in the arm could be due to compression of nerve roots in the spine, as seen in cervical spondylosis, or to an attack of angina pectoris. The sensation is likely to be spasmodic and associated with exercise or some other stress in the latter case, and of a more continuous nature in the former. A history of frequent falls with no loss of consciousness suggests a lesion in one of the areas of the brain dealing with balance and posture, such as the cerebellum or basal ganglia. Such episodes can be seen in patients with Parkinson's disease or in multiple sclerosis. Where loss of consciousness has occurred, the period of unconsciousness and the age of the patient should be taken into account when making a diagnosis. The presence of a severe headache is an important sign, since although it often has a completely benign cause, it may also indicate one of several underlying more serious causes, e.g. brain tumour or subarachnoid haemorrhage or the less sinister migraine or tension headache. Again, the onset, nature and duration of the headache should be established.
135
Social habits
Smoking and alcohol consumption should be noted. Smoking is a risk factor for certain conditions such as atherosclerosis and therefore CVAs. Chronic alcoholism can affect both motor coordination and memory (Korsakoff's psychosis). The actual cause is an alcohol-induced thiamine deficiency which damages the limbic system (Wilkinson 1993b). Such patients appear alert and fully conscious, but recent memory of time and place is severely impaired. The patient denies any loss of memory and frequently attempts to disguise the deficit by confabulation. Similarly, indications of a lifestyle that increases the risk of contracting the HIV virus, such as intravenous drug abuse, may explain a neurological deficit, since the infection can produce a progressive encephalopathy. Gender
Some conditions occur much more frequently in one sex than the other. For example, myasthenia gravis affects females more than males whereas Duchenne's muscular dystrophy, which is an X chromosomal-linked disease, is seen much more in males. Age
There is a general slowing in the passage of impulses throughout the nervous system with age, as shown by nerve conduction tests. Defective sensory perception is present in around 20% of people over the age of 65 years (Ch. 18). The likelihood of neurological abnormalities increases with advancing years. In addition, many conditions affecting the nervous system have typical onsets at particular ages. For example, shingles (herpes zoster), parkinsonism and CVAs are all associated with the over-60 age group, whereas Charcot-Marie-Tooth disease usually manifests itself in people in their twenties and some forms of spina bifida have observable effects from birth. However, where two or more systemic conditions coexist the picture may be altered - for example, patients with dia-
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SYSTEMS EXAMINATION
betes mellitus or sickle cell anaemia are predisposed to earlier onset of CVAs. Coexisting chronic disease can also be helpful in diagnosing the cause - for example, atherosclerosis and hypertension are major risk factors for strokes (McLeod & Lance 1989a).
Observation The patient should be observed while walking, sitting and speaking as well as while performing particular tasks. A change in the level of consciousness, inability to follow simple instructions and deficits in voluntary movement or sensation, including the presence of pain, all provide important clues. Important points to note are: • The affected areas of the body, their distribution and whether one or more modalities are involved. • Whether the effect is uni- or bilateral. • If affecting movement, whether it causes weakness or complete paralysis. • Whether it involves particular muscles or particular actions. • Whether it produces any change in muscle tone and bulk. • If the deficit is affecting sensation, whether the sensation is altered (paraesthesia) or lost (anaesthesia). • The presence of a deformity, e.g. a cavoidtype foot and clawed toes are often seen with spina bifida occulta. • Presence of tremors. Tremors can have a physiological cause or be associated with a neurological deficit. The exact nature of the tremor should be noted, when it appears/ disappears, area of body involved, etc. The causes of tremor are summarised in Table 7.9.
ASSESSMENT OF THE LEVEL OF CONSCIOUSNESS The cerebral cortex and the reticular formation of the brain stem are the two areas of the brain most concerned with maintaining consciousness. The general level of the patient's awareness, ability to
answer questions and follow instructions can all give indications of the level of consciousness.
History Any history of loss of consciousness should always be questioned further, to try to establish whether the cause was: • a simple faint • transient ischaemic attack (TIA) or full-blown stroke • an epileptic episode • a metabolic disorder such as a hypoglycaemic coma. Simple faints (syncope) are always due to a temporary interruption of blood supply to the brain, which is rapidly restored by the prostrate position of the patient. This may be caused by: • benign causes, such as emotional shock, causing vasovagal syncope • autonomic neuropathy if the fainting episode is associated with a change to an upright posture
Table 7.9
Classification of tremors and their likely causes
Type of tremor
Condition
Physiological
Maintenance of posture is accompanied by a tremor (10Hz). This may be exacerbated by anxiety, fatigue, thyrotoxicosis
Age (senile)
With age the normal physiological tremor slows to 6-7 Hz. As a result the tremor becomes more noticeable especially when undertaking a slow motion such as picking up a cup to drink from
Resting
Tremor that is present during rest (4-5 Hz), seen in parkinsonism
Intention
Tremor that increases as the individual tries to undertake a coordinated movement, seen with cerebellar dysfunction
Essential
Postural tremor similar to a physiological tremor but of much greater amplitude, usually hereditary
Drug-induced
Tremor similar to an essential tremor may occur in 40% of patients treated with barbiturates
NEUROLOGICAL ASSESSMENT
137
• serious causes such as haemorrhage or anaphylactic shock.
• whether the patient can follow instructions • the patient's response to stimuli.
Strokes are the result of prolonged/permanent interruption of the blood supply to the brain and are the most common condition to affect the CNS. TIAs are a temporary interruption in the vascular supply to the brain and like strokes usually occur in the older person (60+). Both strokes and TIAs are primarily caused (80% of cases) by thrombosis resulting from atheromatous plaques in cerebral vessels, haemorrhage being the cause of the remainder (McLeod & Lance 1989a). TIAs usually last from 1 to 30 minutes and always less than 24 hours. Epileptic attacks can occur at any age and are due to unusual electrical activity in the cortex, which could be caused by a lesion or a tumour.
Levels of consciousness can be graded as shown in Table 7.10.
Observation TIAs may be accompanied by disorders of speech (dysphasia), vision, movement (dyskinesia) or swallowing (dysphagia), depending on the area of brain involved. However, a full recovery is usual. CVAs can result in neurological deficits similar to those seen in TIAs, but are often permanent, though partial or total recovery is possible depending on the extent and site of damage to the brain. Epileptic attacks can involve the whole brain (global) and result in a brief loss of consciousness (petit mal) which may not show any other symptoms or may last much longer, being accompanied by tonic-clonic jerks (grand mal). Such an attack is often preceded by an 'aura' and the patient may cry out. Attacks can also be focal, as in a Jacksonian attack, which affects only the primary motor cortex and in which different parts of the body show jerks as the attack spreads over the motor cortex.
Hospital tests The following is a brief summary of some of the hospital tests that may be undertaken if a patient shows an altered level of consciousness. Occuloplethysmography. This is a non-invasive test to detect carotid lesions that cause a reduction in blood flow to the ipsilateral orbit compared to the opposite eye. Duplex Doppler ultrasound. This technique uses sound waves of 4-8 MHz, which are beyond the range of human hearing. The transmitted beams are reflected from their interface with tissues in amounts proportional to the density of the tissues. The difference between transmitted and reflected beams is proportional to the density of the tissues and is used to create an acoustic image. In this particular technique, twodimensional B-mode scanning is used, which gives greater resolution than the M-mode scanning of conventional Doppler. Duplex Doppler may reveal stenosis or occlusion of the carotid arteries, a possible cause of a CVA or a TIA, and is often used prior to an angiogram.
Table 7.10 Assessment of the level of consciousness (McLeod & Lance 1989) Level
Observable effects
Alert wakefulness
Patient is fully aware of environment and self and responds to stimuli
Confusion
Patient shows lack of attentiveness, cannot concentrate and has impaired memory
Delirium
Patient is anxious, excited, agitated and may be hallucinating
Lethargy
Patient is drowsy but responds to verbal stimuli
Stupor
Patient is unconscious but responds to pain
Coma
Patient cannot be roused
Clinical tests In the clinic the following can be used to establish the level of consciousness: • the patient's response to a question and answer schedule
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SYSTEMS EXAMINATION
Angiography. Interarterial angiography with injection of a radio-opaque dye into the suspected artery will show atherosclerotic plaques in cerebral vessels, which are a common cause of embolitic strokes. Brain scans. Computed tomography (CT) or magnetic resonance imaging (MRI) can be used to confirm TIAs, full-blown CVAs, neoplastic mass or epileptic foci. Both techniques produce digitised images that can be numerically graded according to the pixel value of the matrix. This can then be converted to a grey-white scale. CT uses X-rays to scan the brain. MRI uses radiofrequency pulses that excite the protons of tissue. Electroencephalogram (EEG). EEGs, or 'brain waves', are traces which show the electrical activity of the cortex, as measured by scalp electrodes. EEGs are normally used to confirm a clinical diagnosis and locate the focus of epilepsy. Lumbar punctures. A hollow needle is inserted into the spinal canal through the intervertebral space between L3 and L4 or L4-5 to withdraw cerebrospinal fluid. This is analysed for microorganisms, glucose levels, protein levels, blood cell types and concentration and hydrostatic pressure. It is based on the fact that many central nervous disorders affect the blood-brain barrier and allow passage of substances normally held in check. The blood-brain barrier is affected by inflammation, infection, haemorrhage and degenerative diseases such as muscular sclerosis and epilepsy. It is performed where bacterial or viral infection in the brain such as encephalitis, meningitis or the Cuillain-Barre syndrome, abscess, tumour or haemorrhage is suspected. Raised pressure measurements can indicate presence of infection or a tumour. A bloody aspirate indicates cerebral haemorrhage. Myelography. This test is usually combined with MRI or CT investigations. A radio-opaque dye is introduced into the subarachnoid space via a lumbar puncture and with the patient on a tilt table, the fluid is manoeuvred to the suspected area. It is used to diagnose tumours of the spinal cord, diseases of the intervertebral disc space, bony abnormalities and spondolytic lesions of the vertebral column.
Laboratory tests These involve DNA testing to detect mutant genes and other biochemical tests to detect faulty enzymes, and are used for diagnosis of hereditary metabolic diseases which affect the CNS such as Huntington's chorea, familial Alzheimer's disease, Tay-Sach's disease, Charcot-Marie-Tooth disease and inherited myopathies such as McArdle's syndrome.
ASSESSMENT OF LOWER LIMB SENSORY FUNCTION It is important that the sensory system is intact in
order that a person can respond to his external and internal environment. Failure to respond, especially to noxious stimuli, can lead to serious pathological changes and may even be lifethreatening. Some patients may be unaware that sensory loss has occurred; it is therefore essential that the practitioner assesses the functioning of the sensory system. Assessment involves checking whether sensory units are functioning normally and, if not, the extent of damage and the possible cause. Sensory deficits may arise as a result of damage to: • parietal cortex • ascending pathways • receptors. Conditions which may cause sensory deficits are outlined in Table 7.11. The most important area of the brain for somatic sensory perception is the parietal cortex Table 7.11
• • • • • • • •
Causes of sensory deficits
Diabetes mellitus Subacute combined degeneration of the spinal cord (vitamin 8 12 deficiency) Congential absence of particular sensory neurones Spina bifida Syringomyelia Tabes dorsalis Nerve injuries Guillain-Barre syndrome MUltiple sclerosis Cord compression/lesion, e.g. tumour (Brown-Sequard syndrome) Chronic alcoholism
NEUROLOGICAL ASSESSMENT
(see Fig. 7.12). Any damage to this area, whatever the cause, will produce a contralateral sensory deficit in the appropriate part of the body. Damage to the occipital lobe (striate cortex) will produce visual disturbances. The most common cause of such neurological deficits is an occlusion or haemorrhage of one of the cerebral arteries. Damage to the ascending tracts in the spinal cord will produce either ipsi- or contralateral effects, depending on the site of the lesion in relation to the point of crossover of the tracts. This is well illustrated in the Brown-Sequard syndrome, where damage to one side of the spinal cord results in: • ipsilateral loss of touch, position sense, twopoint discrimination and vibration sense below the level of the lesion, due to dorsal column injury • contralateral loss of pain and temperature sensation below the level of the lesion, due to damage to the anterolateral tracts. The exact effect of peripheral nerve damage depends on the site and the nature of the damage, since this dictates the repair process (Table 7.12).
History The nature and distribution of any sensory deficit can be an important aid in diagnosing the underlying cause. This may take the form of Table 7.12
Classification of nerve damage
Type
Damage
Neuropraxia
Mild trauma or compression causing local demyelination and leading to temporary loss of function. Full recovery within days or weeks
Axonotmesis
Crush injuries causing degeneration of axon and myelin sheath (wallerian degeneration) Neurolemma sheaths intact and reinnervated
Neurotmesis
Whole nerve axon severed. Surgical repair needed to ensure reinnervation of distal trunk
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complete anaesthesia (total lack of sensation) or paraesthesia (an altered sensation). Examples of paraesthesia are pins and needles, burning, pricking, shooting pain and dull ache. Patients should be asked if they experience any abnormal sensations. Phantom limb. An unusual phenomenon that arises from amputation of a limb is that of 'phantom limb', where the patient has the very real sensation of the amputated limb still being present and behaving just like a normal limb. The most unpleasant effect is the sensation of pain which is said to occur in 70% of amputees (Melzack 1992). The traditional explanation, that this is due to the growth of neuromas in the nerve stumps which continue to generate impulses, cannot be the entire explanation since cutting the afferent pathways from such nerves does not abolish the pain. Melzack has suggested that the phantom sensations are due to learned circuits in the brain that are capable of generating impulses in the absence of sensory inputs. Referred pain. Injury to the viscera often produces pain in a somatic structure some distance away. This is called referred pain. For example, a myocardial infarction can produce pain in the left arm as both the heart and the skin of the left arm have developed from the same dermatomal segment. However, the exact mechanism is still not clearly understood although both convergence and facilitation are thought to playa role (Ganong 1991b). Damage to a spinal nerve may result in referred pain which is experienced around the heel; this occurs if there is damage to S1.
Clinical tests Simple apparatus is all that is needed to undertake an assessment of sensory function. Among the apparatus that can be used are cotton wool, the fine brush of a neurological hammer, a pair of blunted dividers or a pair of blunt-ended orange sticks, a 128 Hz tuning fork, a 109 monofilament, a neurothesiometer, Neurotips (Owen Mumford) and two small metal test tubes, metal being a better conductor of heat than glass. Although all the methods are acceptable, only tests using
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SYSTEMS EXAMINATION
Table 7.13
Sensory testing
Sense
Method
Fibre type and pathway in spinal cord A-beta fibres
Light touch
Cottonwool/brush/monofilament
Two-point discrimination
Dividers, two orange sticks
Vibration (pressure)
Tuning forklneurothesiometer
Temperature
Warm and cold test tubes/ dissimilar metals
Sharp pain/pinprick
Neurotips
Proprioception
Dorsilplantarflexion of hallux
monofilaments and neurothesiometers/biothesiometers have been evaluated. The tests examine the integrity of the afferent pathways that involve the ipsilateral dorsal columns and the contralateral anterolateral columns (Table 7.13). Each test should be demonstrated to the patient first, usually on the back of the patient's hand, so that the test is understood and the expected sensation experienced. It is then possible to ask the patient to compare the same sensations on hand and foot which will indicate the degree, if any, of sensory loss. If the patient suffers from neuropathy of the upper limbs, the demonstration test can take place on the forehead. For the actual test, where appropriate, the patients should have their eyes closed in order that the results cannot be influenced by observing the test. Use of forced-answer questions where possible help to eliminate observer influence, e.g. 'Which is sharper, number 1 or number 2?'. Sham testing, where appropriate, should also be used to rule out any attempts to guess the correct answer by the patient. The test should be repeated three times on the same site and if 2/3 answers are correct, the patient is not considered to have a sensory deficit in that modality. If screening is being carried out to detect generalised neuropathy it is important that the tests involve all the dermatomes at that level (see Fig. 7.8), starting distally and working proximally. As most peripheral neuropathies begin at the most distal site and progress proximally, it is only necessary to test more proximal areas if the test has proved negative distally. The results of each test
I
}
Ipsilateral dorsal column
A-delta and C fibres Contralateral (anterolateral columns)
A-alpha fibres Ipsilateral dorsal columns
should state the extent of any neuropathy, e.g. 'loss of vibration perception from toes to ankles' to aid monitoring of the deficit. If a mononeuropathy is suspected, e.g. anterior tibial damage contributing to foot drop, the dermatomes innervated by that nerve should be investigated. A deficit may not always be due to pathological causes: factors such as overlying callus render the skin less sensitive and the normal slowing of conduction rates associated with ageing results in a reduction in sensation. Testing large-diameter fibres Light touch. Cotton wool, a fine brush or a
109 monofilament can all be used for this test.
The nerves being tested are large-diameter Abeta fibres which ascend in the dorsal columns, transmitting light touch perception. The receptors (Meissner's corpuscles) lie in the superficial dermis. After explaining the test, the patient's eyes should be shut. The patient is asked to state when the foot is being stroked and to indicate the site. The clinician should make no further comment until the test is finished. The skin of the foot is then stroked lightly with a wisp of cotton wool/brush or monofilament. The sense of touch will be reduced in the elderly and in calloused skin (due to thickened skin). The patient may incorrectly distinguish between the lesser toes in this test, but this is normal and is due to the particular innervation of the lesser digits. Two-point discrimination. Blunt-ended orange sticks or the two points of a pair of dividers can
NEUROLOGICAL ASSESSMENT
be used for this test, providing the points of the dividers have been blunted to avoid accidental skin penetration. The nerves being tested are again the large-diameter A-beta fibres, but here the density of the touch receptor field is being assessed. The plantar surface of the foot is usually tested. The patient is asked, with eyes shut, to state how many points can be felt when the tips of a compass lightly press the skin surface simultaneously. The distance between the tips of the compass that allows the patient to detect two points rather than one should be noted. Usually the distance on the foot of a healthy young adult is 2 cm. It will increase with age and if the skin is calloused. The receptors responsible for identifying two-point discrimination are also essential for stereognosis - the ability to recognise objects by touch - and are therefore very important for readers of Braille. Pressure. The 109 monofilament is used for this test. The first monofilament for detecting neuropathy was the Semmes-Weinstein monofilament produced by the Hansen's Disease Center, USA. In theory this monofilament buckles when a force of 109 is applied. Since then a wide variety of monofilaments have been produced, all said to be buckled by the same force of 109. However, McGill et al (1998) and Booth & Young (2000) studied 109 monofilaments from a range of manufacturers and found inconsistencies in their deforming pressures. The clinical relevance of this variation has yet to be determined. Booth & Young (2000) also showed that all monofilaments decline with use and recommended a 24-hour rest should be allowed between repeated use of a single monofilament to allow recovery. A range of monofilaments of different diameters and buckling forces is also available, but these are more useful for research purposes than for routine screening. In view of its small size, low cost and ability in detecting large-fibre neuropathy, the monofilament is considered one of the most useful tools a clinician can possess and is recommended by the International Diabetes Federation, the World Health Organization European St. Vincent Declaration and the International Working Group on the diabetic foot (International Consensus on the Diabetic Foot 1999).
141
The nerve fibres being tested are once more those belonging to the A-beta group of fibres. The receptors are encapsulated and lie in the dermis but are slow adaptors and so detect constant pressure rather than vibration. Both touch and pressure receptors can respond to applied pressure, the difference being in the force used to apply the pressure. Light touch will stimulate a small area of nerve endings and increasing pressure will recruit more and more receptors. When the stimulus becomes pressure rather than touch and whether a different receptor is involved with increased pressure is not clear, so the stimulus is sometimes referred to as the touch-pressure sensation. The monofilament is applied at right angles to the skin surface with just enough pressure to deform the filament into a 'C' shape. Care should be taken not to slide the filament or brush the skin. It should be held in that position for 2 seconds, the patient having been asked to state when and where pressure from the 109 monofilament is felt at various points, with eyes shut. Inability to detect the 109 monofilament is taken to indicate neuropathy of large fibres. Vibration. Either a simple 128 Hz tuning fork or a graduated Rydel-Seiffer version can be used. The nerve fibres being tested are again largediameter A-beta fibres, sensitive to pressure, but this time the deeply placed pacinian corpuscles are particularly sensitive to rapidly changing pressures or vibrations. They are coated with layers of connective tissue, which has the ability to absorb low-frequency pressure changes, so that only high-frequency vibrations such as those produced by the tuning fork will reach the central receptor. The vibrating tuning fork is placed on the skin above a bony prominence such as the apex of the hallux, malleolus or the first metatarsophalangeal joint (MTPJ). It is important to ask the patients to describe what they feel, without any prompting, as most patients will be able to feel pressure, but not necessarily any vibratory sensation. Most patients describe the vibratory sensation as a 'buzzing'. The argument that the tuning fork should not be placed over bone, as
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SYSTEMS EXAMINATION
this augments the sensation, is immaterial, since all damaging pressures to which the foot is likely to be subjected - e.g. tight footwear, ground forces on bony deformities or foreign objects in footwear - compress soft tissue against bone. The Rydel-Seiffer tuning fork is an attempt to produce a semi-quantitative result to enable comparisons to be made with other patients and on different occasions. It has detachable clamps which can be moved to different positions on the prongs, to alter the vibrating frequency from 64 to 128 Hz. As the prongs vibrate, the apex of a cone drawn on the clamps, upright or inverted, will appear to move vertically up or down a scale from 1 to 8. The position of this cone is noted when the patients say the vibration sensation stops. At 128 Hz the apex should reach at least halfway along the scale, i.e. to the number 4 from 1 or 8, depending on which cone is being observed. If vibration sensation is lost before this point is reached, the patient is said to have a vibratory perception deficit. Neurothesiometers provide an alternative method of assessing vibration. The neurothesiometer is basically a vibrator that delivers vibrations of increasing strength, measured in volts per micrometre. The mains-operated version, the biothesiometer, has been superseded by the battery-operated neurothesiometer, to meet Health and Safety requirements. Cassella et al (2000) recommended that rather than using a pistol grip when using the apparatus, the head of the tool should rest in the palm of the operator's hand while being applied to the patient. Only in this way, with no extraneous pressure being applied, could truly reproducible vibratory perception thresholds (VPTs) be determined. The neurothesiometer is positioned over a bony prominence and the strength of the vibrations is increased until the patient can detect a 'buzzing' sensation. This reading is called the VPT and values of over 25 volts are taken to indicate the presence of peripheral neuropathy. The measurement should be repeated three times and the average value taken. An alternative method is to begin with the maximum intensity of stimulus and reduce it until the patient
can no longer detect any sensation. This method is not measuring the same index, however, and the two methods should not be mixed on the same patient. Up to 12 readings can be stored in the memory of the apparatus. Intra-observer error is small. The disadvantages of the apparatus are its cost and weight. Using data from 392 patients with diabetes mellitus, Coppini et al (2000) found that using a VPT score based on comparing the patient's value of VPT with an age-related normal population showed overall better sensitivity and specificity than raw VPT in identifying patients with subclinical neuropathy; they felt that this measurement would be more useful in regular monitoring of diabetic patients. A VPT score >10.1 indicates increased risk of developing neuropathy. Testing small-diameter fibres Temperature. Two test tubes filled with warm and cool water are preferable to immersing saline sachets in cool and warm water, which quickly lose their temperature differences. Metal rods cooled or warmed in water can also be used. A small cylinder made of two metals with dissimilar conductivities is even easier to transport and use, but is not so readily available in the UK. For research purposes, quantitative instruments to measure temperature perception thresholds using thermode devices (Kalter-Leibovici et al 2001) or thermo-aesthesiometers (van Schie et al 1998) have been used. The latter paper concludes that a combined method, using two simple clinical tests and the more sophisticated apparatus, produced the highest sensitivity (76%). This tests the integrity of the warmth and cold temperature receptors that feed into the anterior part of the anterolateral columns. The nerve fibres involved are narrow diameter A-delta and C fibres. Cutaneous receptors detect absolute values rather than the temperature gradient across the skin. Warmth receptors operate in the range of 30---43°C and cold receptors operate in the range of 35-20°C (Vander et al 1998). Temperatures above 43°C or below 20°C will trigger pain receptors. The skin temperature is usually a few degrees cooler than that of core temperature, i.e.
NEUROLOGICAL ASSESSMENT
between 30 and 35°C, though a greater difference may exist in extremes of environmental temperatures. The temperature of the warm water should be above 35°C and that of the cold water below 30°e. Again, with eyes closed, the patient is asked to state which they find the cooler/warmer from the first or second tube presented. Pain. Disposable Neurotips (Owen Mumford) are best used for this test. The Neurotips have a sharp and a blunt end, but the sharp end cannot pierce the skin. Spring-loaded devices which are designed to deliver a stimulus at a force of 40g are thought to be the safest and most reliable way of testing for pinprick sensitivity (Wareham et al 1997). The use of the sharp end of a patella hammer is not advisable as it may be sharp enough to penetrate the skin and is non-disposable. A hypodermic syringe should not be used as the danger of skin penetration is high. This tests the integrity of the sharp pain pathway, which begins with free nerve endings in the dermis. A-delta fibres travel into the spinal cord and synapse in the dorsal horn. The postsynaptic fibres then cross to the contralateral anterolateral columns which travel up to the brain. Using disposable Neurotips and with eyes closed the patient is asked to state which is sharper, the first or second sensation. The two ends should be presented in random sequence to avoid correct guessing by the anxious-to-please patient. Neuropathy does not always mean absence of pain, as is witnessed by diabetic patients with neuropathy who can experience a period of intense pain (Boulton 2000). There are certain perceived wisdoms concerning sensory testing on diabetic patients which the busy practitioner may use to justify using only one of the above methods: • vibration sensation is the first modality to deteriorate • the presence of neuropathy as indicated by failure to detect the 109 monofilament implies neuropathy of all nerve fibres in that limb. There is no conclusive evidence to support either of these statements. Indeed Winkler et al (2000) have reported the existence of a subgroup
143
of type 1 diabetic neuropathy patients who suffer from autonomic symptoms severe enough to warrant treatment, such as severe bladder or gastroparesis, orthostatic hypotension and diabetic diarrhoea associated with a selective smallfibre sensory and autonomic loss with relatively preserved large-fibre sensory modalities such as vibration and touch-pressure sensation. Whether either or both of the above statements can be applied to patients without diabetes is even less certain. A study by Nakayama et al (1998) on rats showed that small-diameter, unmyelinated nerve fibres decrease in number with ageing whereas larger-diameter fibres maintain both conduction ability and numbers. In the absence of solid evidence to the contrary, it would seem advisable to carry out sensory testing on both small and large fibres. However, any testing is better than none. In research studies, a range of sensory tests have been used to calculate a neuropathy disability score (NDS). For further discussion of peripheral neuropathy assessment in patients with diabetes mellitus see Boulton et al 1998, Young & Matthews 1998 and Chapter 17. Tinel's sign. This helps in the diagnosis of nerve compression. Palpating the nerve, or tapping it with a patellar hammer, at the site of compression will often elicit an abnormal sensation distally, but it can also follow the proximal distribution of the nerve. Usually the sensation is paraesthesia (tingling, burning) or is like an electric shock. Tinel's sign can be used to assess for compression of the medial nerve at the wrist or the posterior tibial nerve at the ankle (carpal and tarsal tunnel syndromes). However, no clinical tests for carpal and tarsal tunnel syndromes are entirely reliable (Golding et al 1986), so that the suspicion of such a condition needs to be confirmed by nerve conduction tests (see Hospital tests). Referred pain. Entrapment of a spinal nerve may lead to paraesthesia, pain and weakness of muscles in the lower limb. Normally when pressure is applied to a site of pain, the pain becomes worse. However, with referred pain the level of pain stays about the same. A suspected entrapment of the sciatic nerve usually leads to pain when the affected leg is raised while the patient lies in a supine position.
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SYSTEMS EXAMINATION
Hospital tests Nerve conduction test. Sensory nerve conduction velocities are measured by placing stimulating electrodes on the skin over the nerve to be tested. Recording electrodes, either skin or needle electrodes, are placed either proximally for orthodromic stimulation or distally for antidromic stimulation. The latter gives more consistent results. The lower limit of normal sensory conduction velocities in the lower limb is around 35 m/ s. Values are less than those for the upper limb. A slowing of conduction velocity may be due to a variety of causes (Matthews & Arnold 1991):
• ageing • damage to the cell body as in herpes zoster (shingles) • nerve axon damage as in compression due to a spinal tumour, a slipped disc or tarsal! carpal tunnel syndrome • demyelinisation as seen in Guillain-Barre syndrome. Amplitude of the action potentials and latency are also measured. For a brief discussion of possible findings, see section on motor nerve conduction tests. Nerve biopsy. This can be carried out on sensory, motor and autonomic nerves. A small sample of tissue is removed, using a needle, cone or, if surgery is being performed, a scalpel. The tissue is examined histologically and its interpretation requires great expertise. Characteristics such as a thickened basement membrane, scarring of the myelin sheath, etc., can be identified. Biopsies are carried out where another laboratory test is inconclusive or where no other diagnostic test exists for the suspected condition.
ASSESSMENT OF LOWER LIMB MOTOR FUNCTION If the motor system is functioning normally
muscles should display a resting tone, show good muscle power on active contraction and be able to move against resistance (Ch. 8). The lower limb reflexes, patella and Achilles, should also show a normal response. Reflex path-
ways involve both an afferent and an efferent component and therefore a deficit in either component would be expected to have an observable effect on the response, as would abnormal influences by higher centres on the LMN. Reflex responses can be graded as follows (Fuller 1993a): 3+ == clonus 2+ == increased 1+ == normal +/ - == obtainable with reinforcement o == absent. Values of 2 and above suggest UMN lesions, values of below 1 suggest LMN lesions, peripheral sensory nerve or muscle damage. The patellar reflex. This tests the integrity of the spinal reflex pathway (L3, L4) and demonstrates descending influences on the ventral horn cell. It is important that the limb being tested is as relaxed as possible. The patient should sit sideways on the examination couch with the feet clearing the ground. The practitioner can gently push the leg to be tested, which should swing freely in response. A gentle tap on the patellar tendon with the hammer should elicit a knee jerk. If the leg is not relaxed, the patient should clasp both hands around the other knee and pull (Jedrassik manoeuvre). This releases spinal influence and allows the leg to relax. The test should be undertaken on both legs. The Achilles reflex. This tests the spinal reflex pathway (51, 52). The response is best elicited if the foot of the patient is slightly dorsiflexed by applying gentle pressure to the plantar surface of the forefoot with one hand and tapping the Achilles tendon while the pressure is maintained. The patient can either sit on a couch, with legs extended and the limb being tested crossed over the other, or kneel on a chair, with the foot to be tested hanging slightly over the edge of the chair. In a healthy young adult the forefoot will gently plantarflex. In an elderly person no visible movement may be seen, but a very slight plantarflexion will be felt against the practitioner's hand. Lower limb motor dysfunction can occur as a result of damage to upper motor neurones, lower motor neurones, peripheral nerves or muscles.
NEUROLOGICAL ASSESSMENT
Upper motor neurone lesions Upper motor neurone (UMN) lesions are due to damage occurring anywhere between the cortex and L1 in the spinal cord. Since the spinal cord ends at level L1, lesions below this level will not produce UMN signs. Conditions which can lead to UMN signs are listed in Table 7.14. Although a specific area of the frontal lobes (precentral gyrus) is designated the primary motor cortex (see Fig. 7.12), many neurones from other areas of the cortex are also involved in planning and initiating conscious movement and so can also be called upper motor neurones. This includes neurones of both descending tracts. Damage to the descending tracts will produce the same effects as damage to the neurones themselves. Observation
Damage to the corticospinal neurones and tracts will result in contralateral loss of skilled movements. Lack of movement will in turn eventually lead to a form of muscle atrophy known as disuse atrophy. Damage to the multineuronal pathway causes release of inhibition on the LMNs in the spinal cord, especially those which innervate the antigravity muscles, producing the effect most commonly associated with UMN lesions, that of spasticity or stiffness in the limbs. Gait. Observation of the patient's gait is an important part of the assessment for UMN lesions. In the lower limb the effect is extension at Table 7.14
Conditions associated with UMN signs
• Cerebral palsy due to anoxia at birth • Cerebral vascular accidents Brain injury • Friedreich's ataxia Spinal injury Brain or spinal tumours Amyotrophic lateral sclerosis (motor neurone disease) • Vitamin B12 deficiency • Multiple (disseminated) sclerosis • Later stages of syringomyelia
145
the hip and knee, with plantarflexion and inversion of the foot. If the effect is unilateral, the person is described as hemiplegic. The inability to flex the knee and hip leads to a circumductory gait, with the lateral border of the forefoot and toes often scraping the ground. If both sides are affected the person is paraplegic and the gait is described as a scissor gait, with the knees adducted and feet abducted. Walking aids such as Zimmer frames are essential. Clinical tests Clasp-knife spasticity. The affected limb will be initially stiff to passive stretch, but if gentle stretch is continued, the limb may suddenly relax, rather like the opening of a clasp-knife. This is due to a length-dependent inhibition of the stretch reflex (see Fig. 7.16). Tendon reflexes. Due to the reduced inhibition by the multineuronal tracts, the alpha LMNs responsible for the contraction of extrafusal fibres are hyperexcited. This results in exaggerated patella and ankle tendon reflexes and clonus - increased rhythmic contractions elicited at the ankle or patella by causing brisk stretch of the muscles. More than three contractions as a result of testing the patella or Achilles reflex is indicative of UMN damage (Fuller 1993b). Plantar reflex. Damage to the corticospinal neurones or their axons has another effect that is clinically detectable, the so-called plantar reflex or Babinski sign. It has been suggested that the abnormal reflex, a dorsiflexing big toe, is due to release of a spinal inhibitory reflex (Van Gijn 1975). The plantar surface of the foot is stroked firmly and briskly from the posterolateral border of the heel to the hallux as shown in Figure 7.17. The normal response is a slight plantarflexion of the hallux and lesser toes, although no response is also often seen, especially in the elderly where the sensory pathway may be affected. In patients with corticospinal tract dysfunction, the hallux will extend (dorsiflexion of the hallux) and the lesser toes may fan out. This is the extensor response, sometimes referred to as a positive Babinski response. However, the normal response does not become established until the
146
SYSTEMS EXAMINATION
will be on the same side, below the level of the lesion (Case history 7.1). /
Hospital tests
l
The use of tests to diagnose UMN lesions will vary according to the suspected cause. For example, brain scans are indicated if a CVA is suspected, whereas a spinal radiograph would be used if a tumour of the spine was suspected.
Lower motor neurone lesions
A
\
B
,
e
Figure 7.17 The Babinski response A. Eliciting the response B. Flexor response (normal response) - toes plantarflex e. Extensor response (positive Babinski sign) - toes dorsiflex.
person has learnt to walk and so an extensor response is quite normal in babies. It is important not to rely only on this test for diagnosis of UMN lesions as it is easy to elicit a pain withdrawal response which may appear similar to an extensor response. The rest of the clinical picture should also suggest UMN lesions. Muscle tone. Due to the release of spinal inhibition in UMN conditions, the LMNs will be in a hyperexcited state and so will be firing more frequently. This will result in greater muscle 'tone' and the affected muscle will feel very firm or tense. Any condition which causes damage to the UMNs or their descending tracts can produce UMN signs. If the cortex is affected, the effects will occur on the contralateral side of the body, and if the lesion is in the spinal cord, the effects
As the lower motor neurone cell body, its efferent fibres, the neuromuscular junction and the 10-600 skeletal muscle fibres it innervates all act as a coordinated whole, damage to any part of this motor unit will produce similar effects of weakness (paresis) or complete loss of function (paralysis) and reduced or absent reflexes. Diseases principally affecting the muscles are called myopathies, but this can be confusing as often the cause is lesions in the LMN which have given rise to atrophy of the muscle. Therefore, assessment of all parts of the motor unit will be considered in this section. For classification of myopathies, see Table 7.15. Since LMNs or their spinal nerves exit at all segments of the spinal cord, LMN symptoms can be seen as a result of damage to any segment from
Case history 7.1 A 70-year-old female Caucasian presented to the clinic complaining of excessive wear on the lateral border of the left shoe and a corn on the dorsum of the fifth toe. The patient walked with a stick and had a slow, circumducted gait; the left arm was held in a flexed position. Neurological assessment revealed normal tendon reflexes and muscle power in the right leg but exaggerated tendon reflexes and an extensor plantar response (positive Babinski sign), clonic spasm of the muscles and signs of muscle atrophy in the left leg. Diagnosis: History taking revealed the patient had suffered a major eVA, which had affected the right cortex. The clinical features were consistent with the history. Fortunately for the patient she was righthanded so her speech was not affected and she was still able to feed herself and write.
NEUROLOGICAL ASSESSMENT
Table 7.15
147
Classification of myopathies
Classification
Descriptor
Inherited
Muscular dystrophies (at present untreatable) Duchenne's - X-linked recessive condition. Commonest and most serious of the inherited dystrophies. Affects males, females are carriers. Onset before age 10 years. Weakness in proximal and girdle muscles of lower limb first, later upper limbs also. Hypertrophy and later fatty infiltration (pseudohypertrophy) of calf muscles. Cardiac muscle also affected. See ele vated levels of serum phosphokinase. Death from respiratory failure usual between 20 and 30 years Becker's - X-linked recessive condition. A more benign variety of the above Dystrophia myotonica - autosomal dominant condition. Gene located on chromosome 19. Insidious onset, usually between 20 and 50 years, but can be present earlier. Progressive weakness and wasting of distal as well as proximal limb muscles, facial and sternomastoids. Cardiomyopathy, cataracts and frontal baldness also common. Myotonia is failure of muscle to relax immediately after contraction. Patient cannot open hand quickly after making a fist. Faulty gene leads to defective chloride ion transport, resulting in membrane hyperexcitability Facio-scapulo-humeral-autosomal dominant condition - benign, often asymptomatic. Wasting and weakness of facial, scapular and humeral muscles mean patient has difficulty in whistling, heavy lifting, etc., as well as scapula in abnormal position Limb girdle - variable inheritance (may be treatable, depending on cause). Several causes: specific biochemical defect, benign form of motor neurone disease, polymyositis, hormonal and metabolic disease
Biochemical defect
McArdle's syndrome. Abnormality of glycogen metabolism due to deficiency of muscle phosphorylase. Patient suffers from fatigue, cramps and muscle spasm. Malignant hyperpyrexia. No muscle wastage or weakness. Symptoms occur during or immediately after administration of a general anaesthetic, especially if halothane or the muscle relaxant suxamethonium chloride is given. Defect in calcium metabolism gives rise to prolonged muscle contraction, in turn raising body temperature. Fatal in 50% of cases
Acquired inflammatory
Polymyositis-autoimmune disease. Infiltration of monocytes and muscle necrosis. Weakness of proximal limb, trunk and neck muscles. Patient has difficulty raising hands above head, getting up out of low chairs and bath. May be associated pain on muscular exertion Dermatomyositis. As above, with additional involvement of skin of face and hands, with erythematous rash
Non-inflammatory
Secondary to high-dose steroids and thyrotoxicosis. These are the most usual causes, but can also be associated with alcoholism, Cushing's disease, Addison's disease, acromegaly, osteomalacia and malignancy. See weakness of proximal limb muscles and shoulder girdle. Trunk may also be involved
C1 to 55. However, due to the anatomy of the spinal cord any damage to the cord from L2 will only result in an LMN lesion. It is possible to see a combination of UMN and LMN symptoms if the lesion is between C1 and LI, e.g. syringomyelia. The conditions that can lead to lower motor neurone lesions are listed in Table 7.16. Observation If the pathway is interrupted or damaged in any
way, either at the level of the cell body or along
Table 7.16 Conditions associated with lower motor neurone lesions
• Poliomyelitis • Injury to lower motor neurone and/or peripheral nerve • Motor neurone disease Syringomyelia Vitamin B12 deficiency Cord compression/lesion (Brown-Sequard syndrome) Spina bifida • Charcot-Marie-Tooth disease
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SYSTEMS EXAMINATION
Case history 7.2
Case history 7.3
A 54-year-old male Caucasian first presented to the clinic complaining of corns and callus under the metatarsal heads of both feet. He was unable to bend down to cut his toe nails. A vascular assessment revealed weak pulses in both feet, with the right foot being cold. A neurological assessment revealed dimished reflexes in the right leg and absence of vibration sense in the right foot. Two-point discrimination was 2 ern in the left foot and 10 cm in the right foot. Orthopaedic examination showed a leg length discrepancy of 2.5 ern, the right leg being the shorter and having developed a functional equinus at the ankle. Muscle wastage was apparent in the lower limb of the right side. The patient walked with a limp. Diagnosis: The signs and symptoms are all consistent with poliomyelitis. The patient had contracted the virus when a child. The lower motor neurones of the right side of the spinal cord at the level of the lumbar plexi had been affected.
A 52-year-old Caucasian female presented to the clinic with plantar callus and fissuring, which had arisen following plantar fasciotomy to correct 'clubbed feet'. The patient stated that she had been born with normal feet, but by the time she was 6 years old she could not run or jump properly and by the time she was an adolescent her feet had become high-arched and inverted. She had noticed a gradual weakness in her arms and legs and on one accasion, when 41 years old, she had almost dropped a baby while working as a nursing auxiliary. This incident had caused her to be sent for a neurological examination which revealed slowed motor nerve conduction velocities. She had a recent history of several falls, with her ankle 'going over'. She also complained of aching joints in the feet, knees and hips. Her 27-year-old son was similarly affected. Neurological examination showed all sensory perception except vibration to be normal, but reflexes were absent. Muscle power was reduced in all limbs and muscle wasting of hands, feet and calf muscles was noted. Orthopaedic examination showed reduced dorsiflexion and eversion, with a pes-cavus-typa foot and high-stepping gait. Diagnosis: The patient suffered from Charcot-Marie-Tooth disease, also known as peroneal muscle atrophy. It is an inherited peripheral neuropathy and exists in more than one form, the two most common forms being autosomal dominant.
its axon, then the impulse cannot reach the muscle. The result will be weakness (paresis) or flaccid paralysis, depending on the site and extent of the damage. The sites of damage may involve: • lower motor neurone, e.g. poliomyelitis virus (Case history 7.2) • peripheral axon, e.g. diabetes mellitus • neuromuscular junction, e.g. destruction of cholinergic receptors of the skeletal muscle as in myasthenia gravis. Myopathies will also produce weakness or paralysis, even if the lower motor neurone is intact. In contrast to UMN lesions, which affect particular movements, LMN lesions and myopathies affect particular muscles (Case history 7.3). For example, if the tibialis anterior nerve is affected the anterior tibial muscle is unable to control deceleration of dorsiflexion at the ankle in gait, producing a characteristic slapping gait (Root et al1977). Nerve impulses are essential to the health of the muscle, so that lack of impulses leads to much more rapid atrophy of muscle, skin and other soft tissue than seen in UMN lesions. This is known as denervation atrophy. In addition, the denervated muscle becomes highly sensitive to
very small amounts of neurotransmitter (acetylcholine), possibly due to upregulation of receptors. This results in a quivering of the muscle (fasciculation), seen on an electromyogram as fibrillation. This effect will not be seen if the lesion is in the muscle itself. Clinical tests Muscle power: Muscle power can be graded according to the Medical Research Council scale (Fuller 1993c) as follows: 5 = normal power 4+ = submaximal movement against resistance 4 = moderate movement against resistance 4- = slight movement against resistance 3 = moves against gravity but not resistance 2 = moves with gravity eliminated 1 = flicker a = no movement. A reduced strength of contraction suggests paresis or paralysis.
NEUROLOGICAL ASSESSMENT
Fatiguability. If the site of the lesion is the neuromuscular junction, the muscle will show a sliding decrease in response or fatiguability as seen in myasthenia gravis. The acetylcholine receptors are destroyed in an autoimmune attack and although the first quanta of neurotransmitter can diffuse to remaining receptors, subsequent release of neurotransmitter is less and less likely to make contact and so the response fades. The muscle cells are able to replace the receptors but the autoimmune attack will strike again, in the same or different muscles. Muscle tone. In the skeletal muscles of a healthy person there will always be some motor units firing, which means that the muscle will feel firm. This is referred to as the 'tone' of the muscle. In LMN or muscle damage, the muscle will feel flabby, because of loss of this tone. Tendon reflexes. Reflexes will be weak or absent, because of interruption of the final common pathway. A single reduced or absent reflex suggests mononeuropathy or radiculopathy. A reduction or absence of all lower limb reflexes suggests polyradiculopathy, cauda equina lesions, peripheral polyneuropathy or a myopathy. In the latter there will be no sensory deficit.
Hospital tests
Again, the tests selected vary according to the suspected cause. For example, if diabetic polyneuropathy is suspected, the diagnosis could be confirmed by a combination of sensory testing, nerve conduction tests and blood glucose measurements. Nerve conduction. To measure motor conduction velocities the stimulating electrode is placed along the path of the nerve and the recording electrode is placed over the belly of the muscle. Amplitude and duration of the action potential are also recorded. The lower limit of normal conduction velocities in the lower limb is 40 m/ s. Nerve conduction tests, whether sensory, motor or mixed nerve, do not give definitive diagnoses but help to confirm diagnosis: e.g. by comparing the affected side with the healthy side
149
as in diagnosing tarsal tunnel syndrome (Galardi et al 1994) or by distinguishing between axonal degeneration and segmental demyelination, the two chief pathological processes occurring in peripheral nerve diseases. The distinguishing characteristics are shown below. Axonal degeneration, e.g. the polyneuropathies of diabetes mellitus, alcoholism, toxicity due to heavy metals, nerve entrapment and Friedreich's ataxia (Zouri et al 1998): • see clinical changes first (weakness, numbness, atrophy) • slowing of nerve conduction velocities and loss of large fibres • reduction in action potential amplitude • more prominent distally than proximally (longest fibres affected first) • fibrillation seen on electromyograph. Segmental demyelination, e.g. vasculitis of rheumatoid arthritis (acquired, chronic), Guillain-Barre syndrome (acquired, acute/ chronic), Charcot-Marie-Tooth disease/peroneal muscular atrophy/hereditary motor and sensory neuropathy (inherited, chronic): • electrophysiological changes seen first • dramatic fall in nerve conduction velocities, maybe even total conduction block • worsens proximally. Charcot-Marie-Tooth disease is interesting because two subtypes have been identified: HMSN type I, which shows primarily segmental demyelination, and HMSN type II, which shows mainly axonal degeneration (McLeod & Lance 1989b). Electromyography. This uses a needle electrode inserted into the muscle to show the electrical activity of the muscle in response to an electrical stimulus. Abnormal results are detected in dysfunction of motor nerves, neuromuscular junction lesions and in myopathies (Matthews & Arnold 1991). Electromyography is the only means of electrophysiological testing for myopathies: • if due to motor nerve denervation (e.g. poliomyelitis), will see reduced recruitment,
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SYSTEMS EXAMINATION
Table 7.17
Differences between upper motor neurone and lower motor neurone lesions
Upper motor neurone
Lower motor neurone
Exaggerated tendon reflexes
Loss of tendon reflexes
Extensor plantar response (positive Babinski sign)
Flexor plantar response (negative Babinski sign)
Loss of abdominal reflex
Normal abdominal reflex
Normal electrical excitability of muscle
Fasciculation (fibrillation seen on EMG)
Some muscle wasting over a period of time due to lack of use
Marked muscle wasting occurs relatively quickly
Increase in muscle tone (clonus)
Flaccid muscles (lack of tone)
Whole limb affected
Certain muscle groups affected depending on site of damage; deformity due to contracture of antagonists
fibrillation, then a reduction in nerve action potential amplitude • if due to changes at the neuromuscular junction (e.g. myasthenia gravis), will see a reduction in recruitment • if due to muscle disease (e.g. Duchenne's muscular dystrophy), will see spike potentials on the electromyograph.
reflexes necessary for accurate movement. The basal ganglia also play an important part in the coordination of movement. Damage to these parts of the nervous system may have an effect on gait and coordination. Conditions that may affect coordination and proprioception function are listed in Table 7.18.
Tests may be performed that are specific to particular conditions, such as detection of the presence of antibodies to cholinergic receptors in myasthenia gravis. Nerve and muscle biopsies. These are obtained in an identical manner to those described for sensory nerve biopsies. Histological examination of nerve and muscle tissue will show structural abnormalities, and biochemical tests will detect enzyme dysfunction: e.g. in distinguishing Duchenne's muscular dystrophy from the treatable connective tissue disease of polymyositis, which also shows muscle weakness and atrophy of limb girdles. The differences between UMN and LMN lesions are summarised in Table 7.17.
Observation
ASSESSMENT OF COORDINATION/PROPRIOCEPTION FUNCTION The receptors in the muscles, joints and tendons all feed position sense information to the cerebellum and cortex. In turn, the cerebellum and the cortex bring about vital postural reflexes and
Careful observation of motor activity can give an indication of a deficit in posture, balance or coordination; for example, a stamping gait may be due to loss of proprioception as occurs in
Table 7.18
Conditions that may result in poor coordination
Part
Conditions
Cerebellum
Tumour Multiple sclerosis Arnold-Chiari malformation Friedreich's ataxia Other hereditary spinocerebellar ataxias Hypothyroidism Repeated head trauma as in boxing
Basal ganglia
Parkinsonism Huntington's chorea Wilson's disease Sydenham's chorea
Ascending pathways
Subacute combined degeneration of the spinal cord Guillain-Barre syndrome Tabes dorsalis Alcoholism
NEUROLOGICAL ASSESSMENT
tabes dorsalis, where the ascending tracts in the dorsal columns degenerate. The patient will not know where his body is in space and so lifts his legs much higher than necessary to clear the ground. The patient will also be unaware of when his foot is about to make ground contact and so stamps the foot down. This has the advantage of stimulating pressure receptors proximally, as vibrations from the foot travel up the leg and so provide much needed information to the brain. The cerebellum has modifying influences on the UMNs in the cortex and on brain-stem nuclei. It receives rich proprioceptive information and adjusts the activity of the UMNs to ensure that the actual action and intended action are matched. The cerebellum is essential for smooth, accurate movement and posture and balance. Dysfunction of the cerebellum or of its afferent and efferent tracts produces characteristic effects that are easily observable. Dysarthria. Here cerebellar dysfunction affects the speech muscles and produces a scanning speech, with inappropriate syllabic stress and volume. Dysdiadochokinesia. This is where actions are no longer smooth, continuous movements, but are broken down into their component parts, producing clumsy, jerky actions. Tremor. The tremor associated with cerebellar defect is due to the dysfunction of the stretch reflex and is an intention tremor, i.e. one which increases in amplitude as the person tries to carry out any tasks with the affected limb. The tremor disappears at rest. Gait. If maintenance of balance is upset, the patient will feel unsteady and adopt a wide base of gait. As voluntary movement is also affected, the gait will be clumsy or staggering, as if drunk. Such gait is described as ataxic. The patient may complain of deviating to one side, which suggests the dysfunction is limited to that hemisphere. Basal ganglia. Although the basal ganglia also have a modifying role on voluntary movement, the effects of their dysfunction is quite different from that of the cerebellum. Damage to the basal ganglia produces either a poverty of movement
151
(hypo /bradykinesia) as seen in Parkinson's disease, or jerky writhing movements (choreoathetosis) as seen in the inherited disease of Huntington's chorea (Case history 7.4) or the benign and brief effects of Sydenham's chorea, associated with rheumatic fever.
Clinical tests Proprioception in joints. To test proprioception distally, the practitioner holds the sides of the hallux between forefinger and thumb. While the patient's eyes are shut, the toe is moved up and down and the patient should be able to state the final position of the toe. The sides of the hallux are held rather than the dorsal and plantar surfaces, to avoid additional pressure information being generated. This information travels from receptors in joints in the largest-diameter, fastest nerve fibres of the A-alpha class into the spinal cord, up to the cerebellum in the ipsilateral spinocerebellar tracts and to the conscious cortex in the dorsal columns. A positive result shows that the pathway to the cortex is intact. An inability to give the correct responses would be seen in conditions such as tabes dorsalis. Romberg's sign. This test can be used to confirm proprioceptive disturbance in the dorsal columns or peripheral nerves (Fuller 1993d).
Case history 7.4 A 30-year-old Caucasian male attended the clinic complaining of sore corns. Questioning revealed that he was mentally handicapped. Examination showed warm, hyperhidrotic feet with a poor skin condition and fibrous lesions on the plantar aspect of the feet. The left foot had marked pes cavus deformity. The gait revealed limping and shuffling with excessive arm movement in order to maintain balance. Over a period of a few years further mental and physical deterioration became apparent. The patient's brother was similarly affected and so apparently had been their father. Diagnosis: A diagnosis of Huntington's chorea was made. This disease is inherited as an autosomal condition with complete penetration and late onset, and is characterised by progressive chorea and dementia.
152
SYSTEMS EXAMINATION
Patients are observed standing with feet together and eyes open and then closed. If patients are unable to maintain balance with eyes open, this suggests either a cerebellar or a vestibular defect and if the patients rock backwards and forwards with eyes open a cerebellar defect could be the cause. In such cases this is not a positive Romberg's sign and Romberg's test cannot be performed. Closing the eyes will deprive the patients of visual information, so that the brain has to rely on proprioceptive input: if this is not being transmitted, the patients will sway and find it difficult to keep balance. The practitioner must be ready to catch the patient. A positive Romberg's sign could be due to cord compression, tabes dorsalis, vitamin B12 deficiency or degenerative spinal cord disease. Nystagmus. This is rapid eye movements due to vestibular dysfunction and can be elicited by asking the patient to make a sudden rapid head movement. Its presence indicates a cerebellar lesion. Heel-shin test. The patient is asked to slide the heel of one leg straight down the shin of the other. Patients with cerebellar dysfunction are often unable to do this because of lack of coordination and the heel will follow a wavy path down the other leg. Heel-toe test. The patient is asked to walk in a straight line heel to toe. Patients with cerebellar dysfunction will stagger about the midline, but it must be remembered that there are many other causes of an unsteady gait, especially in the elderly. Finger-nose test. The patient is asked to stand comfortably and then, with eyes shut and one arm outstretched, to bring his fingertip to the nose. Repeat for the other arm. Cerebellar dysfunction will cause the patient to overshoot (hypermetria) or undershoot (hypometria) and miss the nose. Muscle tone. This will be reduced in the affected limbs. Tendon reflexes. These may be unusually sustained, because of the oscillations of an abnormal stretch reflex, but should not be exaggerated. Occasionally, a weak response can be seen in cerebellar syndromes.
Parkinson's disease
This is the commonest extrapyramidal disease and is due to depletion of dopaminergic neurones in the substantia nigra, which project to the caudate nucleus. The most troublesome effect is hypo/bradykinesia, which results in the patient having great difficulty initiating or stopping movement (Case history 7.5). Rest tremor and rigidity are also features. If the hand is affected the tremor may cause the patient to move inde~ finger and thumb in a 'pill-rolling' movement. The patient may show a mask-like face, and speak in a soft voice. Micrographia (small handwriting) is also a characteristic. The antigravity muscles are affected, producing a stooped posture with knees flexed, so that the patient's centre of gravity is no longer over the base of gait. This causes the festination seen in gait, where the patient has to move more and more quickly to avoid falling forward. Gait also tends to be shuffling, with poor heel-ground contact - 'marche ii petits pas'. The tendon reflexes are unaffected. There is a general resistance to passive stretch, described as 'lead-pipe rigidity'. It may show a superimposed intermittent release of the resistance producing a series of jerks, the so-called 'cogwheel' effect.
Case history 7.5 A 65-year-old female Caucasian presented to the clinic requesting nail care. On examination her nails were found to be long, thickened and mycotic and a variety of dorsal, apical and interdigital lesions were present. The patient could appreciate temperature, light touch and pressure and reflexes were normal, but she was very confused and nervous, so that communication was difficult. A full orthopaedic assessment could not be carried out because of the patient's inability to relax her legs and feet. Ankle dorsiflexion was limited and the feet adopted a varus position. Most of the toes showed retraction deformities. Movements were hypokinetic and gait was stooped and shufftinq. There was a minor rest tremor in the right arm. Diagnosis: The symptoms are consistent with Parki.n.son's ~isease. This is a progressive idiopathic condition which gradually affects all limbs. Mental confusion/dementia is not always present.
NEUROLOGICAL ASSESSMENT
In a patient with Parkinson's disease, there is no habituation with the glabellar tap reflex. The glabellar tap reflex involves the practitioner gently, slowly and repeatedly tapping the forehead of the patient between the eyes. In a healthy person, the first tap or two will elicit the eyeblink reflex, but this will rapidly habituate. The frequency of the tremor may be measured via hospital tests but usually the above clinical tests and a positive response to drug therapy will be sufficient to confirm the diagnosis of Parkinson's disease.
ASSESSMENT OF AUTONOMIC FUNCTION As explained earlier, the autonomic nerves innervate the viscera and internal structures such as blood vessels, since they enable the nervous system to maintain homeostasis (see Fig. 7.9). Medical history may reveal abnormalities of bowel and bladder function.
Observation There will be various signs which would suggest autonomic neuropathy such as abnormal sudomotor responses in the skin and abnormal cardiovascular responses in the functioning of the heart and peripheral blood vessels (Faris 1991). Sudomotor neuropathy usually leads to an absence of sweating and a dry skin, although it may produce hyperhidrosis. Vasomotor neuropathy usually produces a warm red skin and an absence of vasoconstriction in response to cold although it may occasionally produce a prolonged vasoconstriction. It may also lead to postural hypotension. Neuropathy of nerves to the cardiac pacemaker tissue may lead to failure of the heart to respond appropriately to the demands of the body, e.g. an absence of tachycardia in response to exercise.
Clinical tests Heart rate. The pulse is taken while the patient is in a supine position and repeated when an
153
upright posture is adopted. The normal response is an increase in heart rate of greater than 11 beats per minute. A loss of response suggests parasympathetic abnormality. Blood pressure. Repeat the above test measuring blood pressure in the two positions. The systolic blood pressure should fall on standing by approximately 30 mmHg and the diastolic pressure by about 15 mmHg. An increased drop suggests sympathetic abnormality. Failure of the cardiovascular system to compensate for postural effects can lead to postural syncope. Valsalva manoeuvre. This is not advisable if there is evidence of proliferative retinopathy. The patient is asked to take a deep breath and exhale against a closed glottis for 10-15 seconds and then breathe normally. The pulse rate is taken during the Valsalva manoeuvre and on release. Heart rate should increase during the manoeuvre and fall on release. No increase during the manoeuvre suggests sympathetic abnormality and no decrease on release suggests parasympathetic abnormality. These tests reveal abnormal responses of the baroreceptor reflex, which implicates defects in innervation of the cardiac pacemaker tissue rather than peripheral autonomic neuropathy, for which there are no clinical tests. Certain signs may suggest peripheral autonomic (sympathetic) neuropathy: • a dry skin due to failure of sudomotor nerves • a warm foot due to lack of arterial vasoconstriction • engorged dorsal veins, due to lack of venous vasoconstriction. Signs of parasympathetic neuropathy are disorders of bowel and bladder function and impotence. The condition commonly associated with autonomic neuropathy is diabetes mellitus, where the foot will often appear red and feel dry and warm. There may be coexistent neuropathy of other small fibres such as pain and temperature fibres (A-delta and C), as well as large-fibre (A-alpha and A-beta) involvement, giving rise to the picture of a typical neuropathic foot (Ch, 17). Less common conditions exhibiting
154
SYSTEMS EXAMINATION
autonomic neuropathy are Cuillain-Barre syndrome, amyloidosis and congenital autonomic failure. It should be remembered that other conditions, such as infection and anaemia, and certain drugs, such as beta-blockers, can also affect the cardiovascular system and may give a false-positive result.
Case history 7.6 A 47-year-old male Caucasian was referred to the clinic with a small ulcer which had existed for 6 months beneath his right heel. When 29 years old, he had visited Nigeria where he had contracted schistosomiasis with resultant paraparesis from his lower abdomen downwards. Since then he had suffered repeated ulceration of both feet. The present ulcer was covered with dense callus which when debrided revealed a lesion 15 mm in diameter and 8 mm deep. Its border was surrounded by macerated callus. A vascular assessment showed no remarkable features, all tests indicating a good blood supply to the foot. The neurological assessment revealed absent reflexes, lack of appreciation of all senses and constant 'pins and needles' sensation around his hips and legs. The skin of the feet was dry. The patient used a walking stick to support his right leg and walked with an abductory gait to achieve ground clearance as the right foot could not dorsiflex. The right leg showed wasting of the triceps surae. Diagnosis: A diagnosis was made of neuropathic ulcer associated with peripheral sensory, motor and autonomic neuropathy due to damage in the spinal cord caused by the parasitic blood fluke Schistosoma haematobium.
SUMMARY This chapter has considered the assessment of the various components on the nervous system. However, as stated earlier, it is important to remember that a number of conditions affect more than one part. Those conditions that result in damage to more than one part of the nervous system are summarised in Table 7.19. It is essential that all parts of the nervous system are assessed in order that the practitioner may acquire a full picture of neurological function (Case history 7.6). A summary of the tests discussed and their interpretation is shown in Table 7.20. Table 7.19 Conditions that affect more than one part of the nervous system Condition
Parts affected
Diabetes mellitus
Sensory, motor (LMN) and autonomic
Motor neurone disease
LMN and UMN
Spina bifida
LMN and sensory
Syringomyelia
Sensory, LMN and UMN
Vitamin B 12 deficiency
Sensory, LMN and UMN
Multiple sclerosis
Sensory and UMN
Cord compression/lesion
Sensory, LMN and UMN
Guillain-Barre syndrome
LMN, sensory and autonomic
Charcot-Marie-Tooth disease
Mainly LMN but possible sensory
Nerve injuries
Depends upon site, may result in LMN, UMN, sensory or autonomic
REFERENCES Booth J, Young M 2000 Testing the reliability of 10 g monofilaments. Diabetic Medicine 17: S74 Boulton A J M (ed) 2000 The pathway to ulceration. In: Boulton A J M, Connor H, Cavanagh P R (eds) The foot in diabetes, 3rd edn. J Wiley, Chichester, p 22 Boulton A J M, Gries FA, Jervell J A 1998 Guidelines for the diagnosis and outpatient management of diabetic peripheral neuropathy. Diabetic Medicine 15: 508-514 Budd K 1984 Pain. Update Postgraduate Centre Series. Update, Guildford Cassella J P, Ashford R L, Kavanagh-Sharp V 2000 Effect of applied pressure in the determination of vibration sensitivity using the neurothesiometer. The Foot 10: 27-30
Coppini D V, Weng C, Young P J, Sonksen P H 2000 The 'VPT score' - a useful predictor of neuropathy in diabetic patients. Diabetic Medicine 17: 488-490 Epstein 0, Perkin G, de Bono D, Cookson J 1992 Clinical examination. Gower Medical, London Faris I 1991 The management of the diabetic foot. Churchill Livingstone, Edinburgh Fuller G 1993a Neurological examination made easy. Churchill Livingstone, Edinburgh, p 135 Fuller G 1993b Neurological examination made easy. Churchill Livingstone, Edinburgh, p 135 Fuller G 1993c Neurological examination made easy. Churchill Livingstone, Edinburgh, p 107
NEUROLOGICAL ASSESSMENT
Table 7.20
155
Summary of neurological signs and symptoms
Feature
Site of lesion
Possible disease
Apraxic gait Aphasia, speech defects Visual defects
UMN (hemisphere)
Stroke Hydrocephalus Head injury
Progressive focal deficit epilepsy
UMN (head)
Tumour, ischaemic stroke, previous intracranial disease
Increased tone and reflexes Weak arm extensors Weak leg flexors
UMN (head/spinal cord)
Stroke Cerebral palsy Neck injury Multiple sclerosis
Hypo/bradykinesia Festinating gait Lead-pipe/cog-wheel rigidity Rest tremor
Neck, cervical region
Basal ganglia
Parkinson's disease
Choreo-athetotic movements
Basal ganglia
Huntington's chorea Sydenham's chorea (rare)
Nystagmus Dysarthria Cranial nerve palsies
Brain stem
Multiple sclerosis Syringomyelia
Nystagmus Dysarthria Scanning speech Diminished, pendular reflexes Intention tremor Ataxic gait Dysdiadochokinesia
Friedreich's ataxia Stroke Tumour Vitamin B12 deficiency Syringomyelia Spina bifida
Cerebellum Spinal cord
Diminished tendon reflexes Paresis/paralysis Pain Paraesthesia/anaesthesia
LMN (Spinal cordi nerve roots/axons)
Poliomyelitis Diabetes mellitus Chronic alcoholism Guillain-Barre syndrome Rheumatoid arthritis Charcot-Marie-Tooth disease Vitamin deficiencies (Bl' B6 , B12 ) Tumour Disc protrusion Trauma
Progressive fatiguability and weakness
Neuromuscular junction
Myasthenia gravis
Proximal limb muscle weakness and wasting, but no sensory loss and no fasciculation
Muscle
Myopathies
Fuller G 1993d Neurological examination made easy. Churchill Livingstone, Edinburgh, pp 41-42 Galardi G, Amadio 5, Maderna L et al 1994 Electrophysiologic studies in tarsal tunnel syndrome diagnostic reliability of motor distal latency, mixed nerve and sensory nerve conduction studies. American Journal of Physical Medicine and Rehabilitation 73: 193-198 Ganong W 1991a Reviews of medical physiology, 15th edn. Lange, London, p 200 Ganong W 1991b Reviews of medical physiology, 15th edn. Lange, London, pp 132-133
Golding D N, Rose D M, Selvarajah K 1986 Clinical tests for carpal tunnel syndrome: an evaluation. British Journal of Rheumatology 25: 388-390 International Consensus on the Diabetic Foot 1999 International Working Group on the Diabetic Foot, p 32 Kalter-Leibovici 0, Yosipovitch G, Gabbay U, Yarnitsky D, Karp M 2001 Factor analysis of thermal and vibration thresholds in young patients with Type 1 diabetes mellitus. Diabetic Medicine 18: 213-217 McClintic J R 1980 Basic anatomy and physiology of the human body. John Wiley, New York
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SYSTEMS EXAMINATION
McGill M, Molyneaux L, Yue D K 1998 Use of the Semmes-Weinstein 5.07/10 gram monofilament: the long and the short of it. Diabetic Medicine 15: 615-617 McLeod J, Lance J 1989a Introductory neurology, 2nd edn. Blackwell Science, Oxford, pp 210-211 McLeod J, Lance J 1989b Introductory neurology, 2nd edn. Blackwell Science, Oxford, p 282 Matthews P, Arnold D 1991 (eds) Diagnostic tests in neurology. Churchill Livingstone, Edinburgh Melzack R 1992 Phantom limbs. Scientific American, April: 90 Nakayama H, Noda K, Hotta H, Ohsawa H, Hosoya Y 1998 Effects of ageing on numbers, size and conduction velocities of myelinated and unmyelinated fibers of the pelvic nerve in rats. Journal of the Autonomic Nervous System 69: 148-155 Root M L, Orien W P, Weed J H 1977 Normal and abnormal function of the foot. Clinical biomechanics - volume 2. Clinical Biomechanics Corporation, Los Angeles, p 254 Vander A J, Sherman J H, Luciano D S 1998 Human physiology, 7th edn. McGraw Hill, New York, pp 238-239 Van Gijn J 1975 The Babinski response: stimulus and effector. Journal of Neurology, Neurosurgery and Psychology 38: 180-186
Van Schie C H M, Abbott C A, Shaw J E, Boulton A J M 1998 A simple method for measuring temperature perception threshold in diabetic neuropathy. Diabetic Medicine 15: S66 Wareham A, Rayman A, Rayman G 1997 Pin-prick sensory thresholds in detecting risk of neuropathic ulceration. Diabetic Medicine 14: S32 Wilkinson I M S 1993a Essential neurology, 2nd edn. Blackwell Science, Oxford, p 135 Wilkinson I M S 1993b Essential neurology, 2nd edn. Blackwell Science, Oxford, pp 49-50 Wilson K J W 1990 Ross & Wilson Anatomy and physiology in health and illness. Churchill Livingstone, Edinburgh Winkler A S, Ejskaer N, Edmonds M, Watkins P J 2000 Dissociated sensory loss in diabetic autonomic neuropathy. Diabetic Medicine 17: 457-462 Young M, Matthews C 1998 Neuropathy screening: can we achieve our ideals? The Diabetic Foot 1: 22-25 Zouri M, Feki M, Hamida C B et al1998 Electrophysiology and nerve biopsy: comparative study in Friedreich's ataxia and Friedreich's ataxia phenotype with vitamin E deficiency. Neuromuscular Disorders 8: 416-425
FURTHER READING Berkow R (ed) 2000 The Merck manual. Merck Sharp & Dohme Research Laboratories, New Jersey Fuller G 1993 Neurological examination made easy. Churchill Livingstone, Edinburgh Joel A, Delisa J B (eds) 1993 Electrodiagnostic evaluation of the peripheral nervous system. In: Rehabilitation
medicine: principles and practice, 2nd edn. Lippincott, Philadelphia Kandel E, [essel T, Schwartz J 1991 The principles of neural science. Elsevier, New York Wilkinson I M S 1998 Essential neurology, 2nd edn. Blackwell Science, Oxford
CHAPTER CONTENTS Introduction 157
Orthopaedic assessment
Terms of reference 157 Position of a part of the body 158 Joint motion 158 Position of a joint 161 Deformity of a part of the body 161
P. Beeson
Why is an orthopaedic assessment indicated? 161 The assessment process 162 General assessment guidelines 163 Gait analysis 167 Abnormal gait patterns
173
Non-weightbearing examination 175 Hip examination 175 Knee examination 181 Tibia/fibularexamination 186 Ankle examination 187 Midtarsaljoint 194 Metatarsal examination 194 Metatarsophalangeal joints (MTPJs) 196 Interphalangeal joints (IPJs) 197 Alignment of the leg and foot 197 Static examination (weightbearing) Limb-lengthinequality 206 Summary 209
202
INTRODUCTION Orthopaedic lower limb assessment is an essential component of the primary patient evaluation. It involves both static and dynamic assessment of musculoskeletal function. Movement of the lower limb involves interaction between the musculoskeletal and the nervous system. This chapter concentrates on the assessment of the musculoskeletal system. Details of the neurological basis of movement and assessment of the nervous system are covered in Chapter 7. The assessment process is based upon an approach which involves general observation of the patient, specific joint observation, palpation, examination of movements and conduction of special tests (McRae 1997). Qualitative, semiquantitative and quantitative measurement techniques are used. The practitioner should be aware of the likely errors that can ensue from such measurements and take these into consideration when interpreting and analysing data from the assessment (see Ch. 4). This chapter concentrates on assessment of the lower limb: details regarding the upper limb and spine have been excluded but can be found in other texts.
TERMS OF REFERENCE The body is divided into three cardinal planes: sagittal, frontal (coronal) and transverse (Fig. 8.1). These planes form the reference points from which to describe: 157
158
SYSTEMS EXAMINATION
I-----=.:~~_t-L=-=-=_~--- Sagittal plane
t - - - - Frontal plane
Transverse plane
Figure 8.1 Cardinal planes of the body: sagittal. frontal and transverse. Sagittal divides the body into right and left halves. frontal divides the body into front and back and transverse divides the body into upper and lower sections. The diagram shows midplanes but the terms refer to any plane parallel to the appropriate midplane.
• • • •
position of a part of the body joint motion position of a joint deformity of a part of the body.
Position of a part of the body The cardinal body planes are used as reference points to describe positions within the body. Anterior (to the front of) and posterior (to the rear of) describe positions in the frontal plane, e.g. the patella lies anterior to the knee joint. Distal (away from the centre) and proximal (towards the centre) describe positions in the transverse plane, e.g. the interphalangeal joints (IPJs) lie distal to the metatarsophalangeal joints (MTPJs). Medial (towards the midline of the body) and lateral (away from the midline of the body) describe positions in the sagittal plane, e.g. the navicular
lies on the medial side of the foot and the cuboid on the lateral side. In the foot, dorsal is used to refer to the top of the foot and plantar to the sole of the foot.
Joint motion Sagittal plane. Motion in the sagittal plane produces extension and flexion. The term flexion denotes the bending of a joint, whereas extension denotes the opposite, i.e. straightening of a joint. The terms used to describe sagittal plane motion in the foot are slightly different from those used to describe such motion at the hip and knee (extension and flexion). At the ankle (Fig. 8.2), subtalar joint (STJ), midtarsal joint (MTJ), metatarsophalangeal joint (MTPJ), interphalangeal joint (IPJ) and first and fifth rays, sagittal plane motion is termed dorsiflexion and planiarilexion. Dorsiflexion denotes a raising of the whole or part of the foot towards the leg, whereas plantarflexion denotes the movement of the dorsal aspect of the foot away from the leg. Frontal (coronal) plane. Motion in the frontal plane produces abduction and adduction of the thigh and leg and inversion and eversion of the foot. This is because the foot lies at right angles to the leg, so the terminology used to describe movements of the foot differ from that for the leg and thigh. Abduction is when the distal segment moves away from the midline of the body and adduction when it moves towards the midline. For example, in order to do the 'splits' gymnasts must abduct their legs. Inversion of the foot is when the plantar aspect of the foot is tilted so as to move towards the midline of the body. Eversion is when the plantar aspect of the foot is tilted so as to face away from the midline of the body (Fig. 8.3). Transverse plane. Motion in the transverse plane produces internal and external rotation of the thigh and leg and adduction and abduction of the foot. Internal rotation occurs when the anterior surface of the distal segment rotates medially in relation to the proximal segment and external rotation when the opposite occurs - the anterior surface of the distal segment moves laterally in relation to the proximal segment (Fig. 8.4). In the
ORTHOPAEDIC ASSESSMENT
B
A
159
C
Figure 8.2 Sagittal plane motion at the ankle A. Dorsiflexion: movement of the foot toward the anterior aspect of the tibia B. Neutral position C. Plantarflexion: movement of the foot away from the tibia.
A
B
Figure 8.3 Frontal plane motion in relation to the midline of the body (black line) away from the line B. Eversion: the foot is moved down and towards the line.
A. Inversion: the foot is lifted up and
160
SYSTEMS EXAMINATION
A
B
c
D
E
Figure 8.4 Relationship between transverse plane motion in the leg and transverse plane motion in the foot A. The feet are mildly abducted; this is the normal standing position B. The legs are externally (laterally) rotated, which results in abduction of the feet (C) D. The legs are internally rotated (medially), which results in the adduction of the feet (E).
ORTHOPAEDIC ASSESSMENT
foot the use of the terms adduction and abduction is dependent upon the site of the reference point: the midline of the body or the midline of the foot. Functionally, the midline of the body is usually used as the reference point: abduction of the foot is where the distal part of the foot moves away from the midline of the body and adduction when the distal part of the foot moves towards the midline of the body (Fig. 8.4). Anatomically the midline of the foot is commonly used as the reference point: e.g. adductor hallucis is inserted into the lateral side of the proximal phalanx of the hallux and is so termed because it brings about adduction of the hallux - movement of the hallux towards the midline of the foot. Triplanar motion. The position of the joint axis together with the shape of the articulating surfaces can result in joint motion in more than one plane. If a joint axis is positioned at an angle of less than 900 to all the cardinal body planes triplanar motion occurs - pronation and supination. Pronation is the collective term for dorsiflexion, eversion and abduction and supination for plantarflexion, inversion and adduction. In the foot the subtalar and midtarsal joints produce triplanar motion.
161
Deformity of a part of the body The term 'deformity' is used to describe a fixed position adopted by a part of the body. Terms used to denote deformity usually have the suffix -us:
• Sagittal plane - equinus when the foot or part of the foot is plantarflexed, e.g. ankle equinus, and extensus when the foot or part of the foot is dorsiflexed, e.g. hallux extensus. Calcaneus, although rarely seen, is used to describe the calcaneus when it is in fixed dorsiflexion, e.g. talipes calcaneovalgus. • Frontal plane - varus and valgus (Fig. 8.5). • Transverse plane - adductus or abductus.
Position of a joint To describe the position of a joint the suffix -ed is used:
• sagittal plane - extended and flexed (thigh and leg); dorsiflexed and plantarflexed (foot)
• transverse plane - internally and externally rotated (thigh and leg); adducted and abducted (foot) • frontal plane - abducted and adducted (thigh and leg); inverted and everted (foot) • triplanar - pronated and supinated (foot). It is important that a distinction is made between joint motion and position; a joint moves in the opposite direction to the position it is in. For example, at heel-strike the foot is slightly supinated (position) but as soon as the heel contacts the ground pronation (motion) occurs at the subtalar joint in order to absorb shock from ground contact.
Genu varum (bow leg)
Genu valgum (knock knees)
A
B
Figure 8.5 Frontal plane deformity of the legs A. Genu valgum (knock knees): the knees are close together and the medial malleoli are far apart B. Genu varum (bow legs): the knees are far apart and the medial malleoli are close together.
162
SYSTEMS EXAMINATION
Table 8.1
Factors that can affect normal function
• Hereditary/congenital problems, e.g. Charcot-Marie-Tooth disease, talipes equinovarus, CDH • Acute/chronic injury causing pain, e.g. slipped femoral epiphysis, ankle sprain • Abnormal alignment secondary to trauma, e.g. femoral/ tibial! epiphyseal fracture • Abnormal alignment (developmental), e.g. internal femoral torsion, genu valgum • Infections, e.g. tuberculosis • Neurological disorders, e.g. CVA • Muscle disorders, e.g. Duchenne's muscular dystrophy • Neoplasia, e.g. osteosarcoma • Systemic disease, e.g. autoimmune (rheumatoid arthritis), bone disease (Paget's disease) • Degenerative processes, e.g. osteoarthritis • Joint hypermobility, e.g. Marfan's syndrome • Osteochondroses, e.g. Perthes' disease • Psychological factors, e.g. attention seeking • Footwear, e.g. high-heeled shoes
WHY IS AN ORTHOPAEDIC ASSESSMENT INDICATED? Normal lower limb function should be pain-free and energy-efficient. The main purpose of the assessment is to identify whether the system is functioning within the boundaries of 'normality'. Normal function can be affected by many factors (Table 8.1). It should be remembered that orthopaedic lower limb problems are not always isolated in origin. They may result from referred pain from a proximal source or can be part of a systemic disorder. It is therefore important that the lower limbs are not examined in isolation and that observation and examination of other parts of the body are undertaken where indicated. In summary the purpose of an orthopaedic lower limb assessment is to: • establish the main complaintts), e.g. pain, stiffness, tenderness, numbness, weakness or crepitus • identify the site of the primary problem - e.g. foot, leg, knee, hip - and try to relate to underlying structures • identify any secondary problems and relate them to the primary problem, e.g. lesion patterns, pronation due to leg-length discrepancy • identify the cause of the problem, e.g. abnormal alignment
• establish how the problem evolved • identify any movement/activity that produces/exacerbates symptoms • identify movement/activity that relieves symptoms • establish any differential diagnoses • utilise the data from the assessment to produce an effective management plan • utilise the data from the assessment to monitor the progress of the condition.
The assessment process When undertaking an assessment of the lower limb it is essential that the system is observed weightbearing (dynamic and static) and nonweightbearing. Differences between the two can help to determine whether compensation has occurred. For example, non-weightbearing assessment may identify the presence of a forefoot varus; observation of the patient's gait may show this problem has been fully compensated through abnormal pronation at the subtalar joint. Conversely, information from the non-weightbearing assessment may explain the cause of a gait abnormality, e.g. a patient may have a bouncy gait due to an early heel lift; non-weightbearing assessment of the ankle joint may reveal that the cause is an ankle equinus due to a short gastrocnemius muscle.
ORTHOPAEDIC ASSESSMENT
To gain a full and detailed picture of the function of the locomotor system, the following factors must be assessed: • • • •
gait alignment and position of the lower limb joint motion muscle action.
Practitioners vary as to the sequence in which they assess the above. There is no one correct sequence; practitioners should adopt the sequence and approach they feel most comfortable with. However, it is essential that a systematic approach is adopted to ensure vital pieces of data are not omitted. For the purposes of this chapter the following sequence has been adopted: 1. Gait analysis. This will focus on the position
and alignment of the body and foot-ground contact. 2. Non-weightbearing. This will focus on the assessment of joints and muscles. 3. Static weightbearing. This will focus on the position and alignment of the body and the relationship of the foot to the ground during stance. To achieve a successful assessment it is important that the patient is at ease and cooperates with and has confidence in the practitioner. The practitioner should always be sensitive to the patient's needs and explain what she is about to do, and why, prior to undertaking the assessment. Qualitative and quantitative measurement should be undertaken where necessary, but the data must be meaningful and reproducible if they are to be of any use in assessing improvement or deterioration. Various measuring devices may be used; their use will be discussed in the appropriate sections.
General assessment guidelines Always observe and functionally assess the joints bilaterally. It is valuable to obtain an overview of both limbs, particularly if the onset of the problem is insidious, the pain is diffuse and nonspecific or if during testing a number of joints appear to be implicated. Where only one limb is affected, it is often helpful to start with the unaffected limb first, then repeat the test on the
163
affected limb. Compare ranges of motion, end feel (the sensation the examiner feels when he pushes the joint being examined to the end of its range of motion) and muscular strength. It is helpful to arrange your testing so that the most painful test is last. This ensures that the condition will not be aggravated by your testing procedure or make the patient apprehensive. Not all of the tests will be necessary for each component of the lower limb assessment. The selection of tests used will depend on the findings as the examination proceeds, and should be influenced by the history and observations in order to rule out needless testing: having said that, it is necessary to be thorough enough to rule out all other possibilities by applying a holistic approach. Exclusion of all possible injured structures in addition to vascular, visceral and systemic conditions will be required. Referred pain associated with local nerve entrapments or radicular patterns of pain in which spinal nerves or nerve roots are irritated need to be considered. In addition, it is important to rule out the joint above and below, especially if the history suggests other joint involvement. Furthermore, it is useful to remember that a problem that affects one part of the system can lead to problems elsewhere in the system. This is because the lower limb functions as one mechanical unit; as a result a problem in one part has to be compensated for in another part of the system. Compensation is a change in structure, position or function of one part in an attempt to adjust to an abnormal structure, position or function in another part. For example, a scoliosis of the spine may lead to an apparent leg-length discrepancy, which will affect foot function. Conversely, a problem affecting the foot, e.g. an uncompensated rearfoot varus, may lead to discomfort/pain at the knee. The process of assessment follows a standard format: • • • • • • •
general observation of the patient specific joint observation palpation examination of joint movement muscle assessment undertaking special tests arranging further investigations.
164
SYSTEMS EXAMINATION
General observation of the patient
The assessment process starts in the waiting room. Observation of the patients' demeanour, facial expression, seated posture and how they get up from the chair will provide valuable clinical information. In addition, the way in which the patient walks into the clinic, together with use of walking aids, provides additional information as to mobility and how this might be influencing lower limb / foot function. Specific joint observation
Observation of each lower limb joint prior to examination is useful to establish the presence of any clinical features synonymous with pathology, e.g. oedema, contusion, erythema, local muscle wasting, alteration in shape or the presence of scars. In addition, comparison of symmetry of contralateral parts, abnormal posture/evidence of limb shortening and abnormal joint movement during gait are additional clinical clues to underlying pathology. Palpation
The process of joint assessment should be based upon the following approach: • • • • •
range of motion (ROM) direction of motion (DaM) quality of motion (QOM) symmetry of motion (SaM) dislocation and subluxation.
Range of motion (ROM) is the amount of motion at a joint and is usually measured in degrees. The ROM at a joint can be compared with the expected ROM for that joint; e.g. if only 20° of motion is found at the first MTPJ when the expected norm is 70° (28% of the normal ROM) it can be concluded that the ability of this joint to carry out normal function is impaired (hallux limitus). Often a guesstimate of the amount of joint motion is made from observation. Protractors, tractographs and goniometers can be used to quantify joint motion (Fig. 8.6). A joint may show a normal ROM but the direction of the motion (DaM) may be abnormal. It is, therefore, important to note the direction as well as the range. For example, the total ROM of transverse plane rotation at the hip is 90°; 45° internal rotation and 45° external rotation. If the ROM is 90° but there is 70° of external rotation and 20° of
Palpation of the limb segment or joint for clinical features such as raised/lowered skin temperature, swelling/effusion, tenderness, pain or abnormal lumps/nodules provides additional information to help establish a diagnosis. Examination of joint movement A
Features of an inflamed joint are redness, heat, pain, swelling and loss of function. Inflammation of a joint may be due to a range of factors: trauma, infection, loose body (osteochondritis diseccans), Examination of the joint, information from the medical and social history and results from X-ray and lab tests will enable a diagnosis to be made. If a patient complains of a painful joint the characteristic features of the pain should be recorded. Prior to examining a joint it is important that the joint is warmed up (moved through its range of motion); this relaxes the ligaments and muscles and also reduces the viscosity of the synovial fluid.
B
.~ ~ c
Figure 8.6 Devices used to measure joints A. Protractor B. Tractograph C. Finger goniometer. D. Gravity goniometer.
ORTHOPAEDIC ASSESSMENT
internal rotation then the ROM would be normal but the DaM would be abnormal. Normal joint motion should occur without crepitus, pain or resistance (quality of motion or QOM). The ROM and DaM of motion of a joint, e.g. hip, should be the same for both limbs (symmetry of motion or SaM). The presence of asymmetry of motion should always be noted. Joint motion can be affected by the ligaments around the joint. It is important as part of joint assessment to identify any dysfunction of the ligaments, e.g. ligament tear or contracture of a ligament. Finally, joints should be assessed as to whether they are subluxated or dislocated. Dislocation occurs where there is no contact between articulating surfaces of the joint and subluxation where there is only partial contact. The range of active and passive movement of each respective lower limb joint should be examined, documented, compared and contrasted with the contralateral side. It is useful to assess whether passive movement of the joint provokes any pain or guarding (sometimes seen in hallux Iimitus). In addition, it is valuable to document the response to resisted testing (strong/weak/painless/painful) and stability of the joint. This will determine the integrity of the articulating surfaces and ligaments. Provoking crepitus on joint movement is an indication of joint damage. Table 8.2 summarises the main joint changes that can be detected during joint assessment. Often it is helpful to be able to differentiate between articular and capsular damage. In a lesser MTPJ this can be achieved by comparing the results of a compression test (compression of the metatarsal head against the proximal phalanx - to test for articular damage) with a distraction test (dorsiflexion/plantarflexion of a distracted proximal phalanx against the joint capsule dorsally/plantarly). Muscle assessment
Muscles bring about motion at joints. To identify the cause of joint dysfunction and/or pain it is important to differentiate between muscle, ligament and joint abnormality. As a number of muscles may affect anyone joint, it is important to
Table 8.2
165
Joint changes
Type of sensation
Indication
Joint stiffness
Inflammatory/degenerative changes
Tightness or tension
Swelling or protective muscle spasm
Popping
Muscle tear or strain
Snapping
Tendon slipping over bony prominence
Clicking
Meniscal tear or patella rubbing femoral condyles
Grating
Osteoarthritis or osteochondritis
Crepitus (tendon)
Inflammation of tendon
Crepitus (joint)
Articular damage or loose body
Tearing
Muscle or ligament tear
Tingling
Neural or circulatory pathology
Warmth
Local inflammation or infection
Numbness or hypersensitivity
Local nerve or nerve root compression
neutralise the effects of other muscles prior to testing the muscle in question. One way in which a muscle can be neutralised is by flexing the joint which the muscle crosses so that tension is removed. Muscles should be tested for: • • • •
strength tone spasm bulk.
Strength. The Medical Research Council (MRC) system is commonly used for grading muscle strength (Crawford Adams & Hamblen 1990):
o = no contraction 1 = a flicker from muscle fasciculi 2 = slight movement with gravitational effects removed 3 = muscle can move part against gravity 4 = muscle can move part against gravity + resistance 5 = normal power. Muscle strength can be assessed by the patient bringing about the motion (active) or by the prac-
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SYSTEMS EXAMINATION
titioner moving the part (passive). Active motion can be tested against resistance, i.e. the practitioner attempts to prevent active motion. Tone. All muscles should show tone. Tone denotes that a muscle is in a state of partial contraction without full movement being necessary. Asking the patient to undertake isometric contraction of a muscle is a useful means of identifying tonal quality. For example, the tone of the quadriceps can be assessed by asking the patient to contract the muscle while the knee is in an extended position. During contraction muscles should feel firm as well as appearing taut. Flaccid muscles lack tone; this is common with lower motor neurone disorders. Absence of tone in young males could be due to Duchenne's muscular dystrophy. Spasm. Muscles may present in spasm and as a result affect joint motion. There are two types of muscle spasm: tonic and clonic. Tonic spasm usually occurs as an attempt by the muscles to stop movement at a painful joint; clonic spasm is associated with neurological (upper motor neurone) deficit and is involuntary. Information from the neurological assessment, medical history and presenting problem should enable identification of the type of spasm. Bulk. Muscle bulk should be observed and comparisons made between the lower limbs. Atrophy of muscle can result in a loss of muscle bulk and may be due to a number of factors, e.g. lack of use, lower motor neurone lesion (Case comment 8.1). Hypertrophic muscles that show normal tone and symmetrical distribution are considered normal and are usually due to the effects of exercise. Unilateral atrophy/hypertrophy can be assessed by observation and measuring the girth of both limbs with a tape measure (Fig. 8.7).
Case comment 8.1 Be mindful of diabetics who inject themselves with insulin. The quadriceps and abdominal muscles are often used and will show patchy loss of fat and muscle.
ligament. The section on non-weightbearing examination will discuss the specific tests used to assess each of the lower limb joints and their associated structures. Arranging further investigations
Usually the information obtained from a detailed history and assessment is sufficient to arrive at a
Undertaking special tests It may be necessary to carry out specific examina-
tion tests so as to confirm a diagnosis or to differentially diagnose between similar conditions. Some clinical examination techniques have been developed so as to test a particular aspect of joint function, e.g. Lachman's test - to assess sagittal plane stability of the knee in an anterior direction and thereby the integrity of the anterior cruciate
Figure 8.7 Assessment of muscle bulk (quadriceps) using a tape measure.
ORTHOPAEDIC ASSESSMENT
diagnosis. Occasionally, however, it may be necessary to arrange specialist investigations to confirm the diagnosis or to consider other options. A number of possibilities are available, including: specialist imaging techniques and haematological, biochemical and nerve function tests. In addition, histological examination of specimens, electromyography (EMG), video/treadmill gait analysis or computerised analysis/ forceplate analysis may be indicated. The choice of investigation will depend upon the patient's individual history. Furthermore, cost restraints, time, availability of each technique and local expertise will also determine which specialist investigations are arranged.
Table 8.3
167
Dysfunctions that can influence gait
Neurological May involve dysfunction of one or a combination of the following parts of the CNS and/or PNS: • • •
motor, e.g. CVA sensory, e.g. tabes dorsalis, blindness cerebellum, e.g. Friedreich's ataxia basal ganglia, e.g. Parkinson's disease
Systemic • • •
joint disease, e.g. rheumatoid arthritis, osteoarthritis, juvenile idiopathic arthritis crystal arthropathies, e.g. gout muscle disease, e.g. Duchenne's muscular dystrophy, dermatomyositis bone disease, e.g. rickets, Paget's disease
Structural
GAIT ANALYSIS
•
Gait involves complex neuromuscular coordination of the lumbar spine, pelvis, hips and those structures distal to them. Any dysfunction in the lower limb will become observable during gait. A variety of neurological, systemic and structural dysfunctions can influence gait (Inman et a11981) (Table 8.3). The effects of the dysfunctions listed in Table 8.3 may lead to gross or relatively minor changes to gait. Gross disorders are readily observed, whereas those that lead to relatively minor changes, e.g. rearfoot varus, may not be so obvious. Gait can be adequately assessed with few aids, providing that sufficient room is available; ideally there should be a walkway 1.1 m wide and 6 m long. A treadmill may be used; this facilitates the observation of a sufficient number of strides without the patient having to make frequent turns and is especially appropriate if there is not enough room for a 6 m walkway. It is important that the patient is appropriately attired (ideally shorts and 'l-shirt) so that key parts can be observed; these are summarised in Table 8.4. This section concentrates on the observation of gait. Methods of analysing gait are discussed in Chapter 12; these can provide a very useful adjunct to information obtained from observation and are particularly useful in the monitoring of gait changes. The patient's gait must be observed from the posterior, anterior and lateral views in order that movement in all three body
planes can be assessed. Gait should be observed with the patient both barefoot and wearing shoes (with and without orthoses). Gait analysis commences with the patient entering the room. At this point the patient is less conscious of being observed and is less likely to act unnaturally. The practitioner's eye should run from the patient's head to ground level, observing foot-ground contact. At this stage there are some key points the practitioner should address about the patient's gait (Table 8.5). Gait is divided into a swing phase and a stance phase; stance phase relates to the period of the gait cycle when the foot is in contact with the ground and swing phase to when it is not. Stance phase is easier to visualise than swing phase; it consists of the contact, midstance and propulsive stages (Fig. 8.8). Contact phase starts when the heel makes ground contact; this is followed by the rest of the foot. During contact phase the foot pronates in order to absorb shock from the effects of ground reaction. Midstance starts when all the foot is in ground contact and ends with heel lift. During midstance the foot starts to re-supinate ready for propulsion. Propulsion starts at heel lift and ends when the hallux leaves the ground.
limb-length inequality, e.g. DOH, polio, femoral/tibial fracture alignment disorders: coxa valgalvara, genu valgum/varum/recurvatum, tibial/femoral torsion, rearfoot varus
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SYSTEMS EXAMINATION
Table 8.4 Anatomical and functional features to observe during gait
Head position Shoulder position •
Arm swing
•
Trunk position/rotation Pelvic tilt Limb motion
•
Thigh segment Patellar position (transverse plane) Knee position (frontal/sagittal plane)
•
Tibial position
•
Ankle Calcaneal position Navicular position Midtarsal joint (position/movement) Metatarsals (anterior/lateral views)
•
Toe position Foot position/shape Muscle activity Propulsion Swing phase
During propulsion the foot continues to supinate; the fifth metatarsal head is the first to leave the ground, followed in sequence by the others. The hallux should be the last to leave the ground. Assessment of foot-ground contact and swing phase can be facilitated by high-quality video recording and playback with freeze frame.
Table 8.5
The movement and relationship of both limbs during gait is summarised in Table 8.6. The following section considers each of the specific pointers listed in Table 8.4. Head. The head should not show excessive movement. Altered positions may include twisting (torticollis), due to muscle contracture, or tilting on one side as a result of pain or limb-length inequality (LLI). In type I compensation for LLI the head will tilt down on the long limb side due to cervical scoliosis. In type II and III compensation for LLI the head will tilt down on the short limb side. Shoulder position. Both shoulders should be level. Unilateral tilting may be due to LLI or scoliosis. In children under 12 years with LLI the shoulders will always tilt down on the short limb side (type III compensation). In adults where secondary scoliosis can present the shoulders will tilt down on the long side (type I and type II compensation). Fixed deformities should be distinguished from flexible vertebral deformities (see static weightbearing examination). Arm swing. Arm swing is a feature of normal forward progression. The arms should swing to even out leg movement. The upper torso will act to decelerate lower limb motion. Some subjects fail to swing their arms; this alone is not abnormal but can affect spine position during walking: there is a tendency to lean either forward or back as the arms do not swing. Arm and hand position may point to signs of injury or motor disability and should be recorded: e.g. flexed position of arm and hand held close to the body suggests a cerebral vascular accident (eVA). In addition, in
Questions the practitioner should consider when assessing the patient's gait
Does the patient lurch or look uncoordinated? This suggests ataxia and requires examination of the cerebellum and nervous system. Does the patient have any postural problem? Is the posture abnormal? Does the spine appear curved? Does one leg/foot lead, followed by the other without obvious asymmetry or alteration in cadence? Does the face shows signs of pain or anxiety? Could this be an antalgic gait? Does the patient appear to be overweight in relation to his/her height? Does the whole foot contact the ground when shod? Does the foot look straight, adducted or abducted?
ORTHOPAEDIC ASSESSMENT
Table 8.6
169
Stance phase of gait showing 'normal' movement of the left and right limbs
Left knee/hip
Left foot
Right knee/hip
Right foot
Knee extended Hip flexed
Heel contact
Knee and hip extended
Heellif!
Knee flexed Hip extending
Foot flat (forefoot loading)
Knee and hip flexing to max
Toe-off
Knee extended Hip extended
Midstance
Knee starts to extend from maximum flexion Hip flexed
Midswing
Knee and hip extended
Heel lift
Knee extended Hip flexed
Heel contact
Knee and hip flexing to max
Toe-off
Knee flexed Hip extending
Foot flat (forefoot loading)
A
B
c
D
Figure 8.8 Series of photographs taken at 400 frames per second A. The right heel contacts the ground; forefoot motion is decelerated by the extensor muscles B. The metatarsal heads have contacted the ground but the toes are still dorsiflexed C. The right foot completes forefoot contact and the left heel is about to leave the ground (heel lift) D. Propulsion: the fifth and fourth toes are no longer in ground contact and the third, second and first are about to follow in that order.
170
SYSTEMS EXAMINATION
patients with LU, the arm on the shorter limb side will be held away from the body to help maintain balance and will hang lower than the contralateral arm. Trunk position/rotation. Observe for obvious structural abnormalities likely to influence gait posture such as spinal kyphosis, scoliosis or lordosis. Excessive amounts of trunk rotation will increase energy expenditure during gait and can often be associated with myopathy such as Duchenne's muscular dystrophy and spastic neurological gaits. In addition, excessive upper body movements with the arms swinging across the body may be caused by faulty hip or lower limb mechanics. Pelvic tilt. This forms the pivot of lower limb function. The pelvis moves in all three cardinal planes in order to provide smooth up and down (sinusoidal) motion. Tilting may arise from neurological problems, spinal deformity, LU (pelvis tilts down on side of short limb) and injury. Pelvic tilting can also present in osteoarthritis of the hip due to weakness of gluteus medius (resulting in Trendelenburg gait). Limb motion. Do the limbs present a normal forward progression during gait rather than the exaggerated circumducted movements typical of a CVA patient? Thigh segment. Thigh movement is a reflection of the transfer of pelvic motion through the hip joint. Excessive transverse plane rotation (internal and external rotation) should be noted; this may be due to a variety of factors, e.g. abnormal femoral torsion or version. Patellar position (transverse plane). As long as the patella proves to have normal alignment then it can be used as a reference point to determine the extent of transverse plane motion of the leg. The amount of transverse plane rotation at the knee should be slightly greater than at the hip and may therefore be easier to observe than at the thigh. At heel contact the leg should internally rotate (patellae face inward); throughout midstance and most of propulsion the leg should externally rotate (patellae face outward) (see Fig. 8.4). Alternatively, if the patella has an abnormal alignment, a bisection line drawn through the tibial tubercle with a black felt marker may assist
observation of transverse plane motion. Excessive internal or external rotation should be noted; it may be due to proximal or distal abnormality. If the patellae are squinting with an in-toed gait it suggests the cause of the in-toeing is suprapatellar, whereas if the patellae are facing forward with an in-toed gait the inference is that the cause of the in-toeing is infrapatellar. Excessive externally facing (fish eye) patellae are generally associated with external femoral torsion. Torque conversion is the means by which motion of the thigh and leg influences the foot; the subtalar joint (STJ) is the interface between the leg and foot and is where torque conversion takes place. Internal rotation of the leg is transferred into pronation of the foot (required for shock absorption) and external rotation of the leg is transferred into supination of the foot (required for stability of the foot during propulsion). However, excessive transverse rotations of the leg during gait will influence the angle of gait and, subsequently, promote prolonged and abnormal pronation or supination of the foot, leading to foot and leg pathology. Knee position (frontal/sagittal planes). Sagittal plane motion of the knee joint during gait is outlined in Table 8.6. Alteration in sagittal plane knee motion will affect the third determinant of gait. If the knee does not flex it causes the hip to lift further and allows greater height on that side. To swing the leg from stance through swing back to stance again the pelvis has to rotate more and has a vertical displacement which should appear obvious. Excessive extension of the knee (genu recurvatum) should be noted if it occurs during gait. Frontal plane problems (genu valgus/varum) can be identified from observing the position of the knees and the tibiae. The normal tibial outline shows a slight genu varum because muscle distribution results in lateral bulk. Bowing of the legs (genu varum) or knock knees (genu valgum) should be noted (see Fig. 8.5). Valgum of the hip (coxa) can produce the effect of a genu varum. In addition, osteoarthritis of the medial knee can cause a genu varum deformity. Conversely, coxa vara can produce a genu valgum. If a genu varum or valgum is present, it should be noted if it is bilat-
ORTHOPAEDIC ASSESSMENT
eral or unilateral. A unilateral deformity may suggest injury, infection or growth disturbance at the epiphysis in earlier life. Tumours are a rare cause but should always be considered. Tibial position. Bowing of the tibia in the frontal plane (tibial varus), a cause of rearfoot varus, or sagittal plane bowing (sabre tibia), seen in Paget's disease, should be noted. Ankle. The ankle complex provides smooth transference of weight from heel to toe. A minimum of 10° dorsiflexion is required to allow the leg to pass over the foot during midstance. Equinus is the term used to indicate loss of dorsiflexion. Toe walking and/ or an early heel lift may indicate an ankle equinus but nonweightbearing examination of the ankle joint must be carried out before a definitive diagnosis can be made. Unstable ankles may have frontal plane instability, which shows as tilting hesitations. The subtalar joint works in concert with the ankle (talocrural) joint. Inman (1976) regarded the talocrural (TCJ) and subtalar (STJ) as the 'ankle joint' because they have a symbiotic relationship. The TCJ provides predominantly sagittal plane motion and the STJ frontal and transverse plane motion. If one of these joints is unable to produce motion, e.g. after surgical arthrodesis (joint in fixed position), then the other compensates. Calcaneal position. The posterior position of the calcaneus should be observed. The calcaneus contacts the ground in a slightly inverted position. As a result of ground contact the calcaneus everts, without the need for active muscle contraction, in order to bring the medial tubercle of the calcaneus into ground contact. The position of the calcaneus moves very quickly from an inverted to an everted position; it is therefore often easy to miss subtle changes. At the end of midstance the calcaneus lifts off the ground in order to prepare the foot for propulsion (Case comment 8.2). An early heel lift or a heel that makes no ground contact suggests a neurological problem, an ankle equinus or hamstring tightness. Rapid eversion of the calcaneus at heel contact can be associated with compensation for a rearfoot deformity, e.g. fully compensated rearfoot varus (sometimes described as a heel strike pronator).
171
Navicular position. At heel contact the foot pronates in order to absorb shock from ground contact. During pronation the talar head ad ducts against the navicular and as a result the distance between the ground and the navicular reduces. As the foot progresses into midstance and then toe-off the foot re-supinates (talus abducts); at this point the distance between the navicular and the ground increases. If the talonavicular prominence is visible for more than a moment, or if the extent of the displacement is abnormal, careful examination of the cause must be considered during the non-weightbearing examination. Midtarsal joint (MTJ). During midstance and propulsion the MTJ plays an important role in maintaining foot stability in order to withstand the forces on the foot generated by uneven surfaces and particularly during propulsion. Functioning of the MTJ is difficult to observe during gait. However, if there is abnormal pronation at the subtalar joint the forefoot will appear abducted on the rearfoot at the site of the MTJ; an increased concavity of the lateral border of the foot at the level of the calcaneocuboid joint will be apparent. This is an important sign of dysfunction, which may result in forefoot deformity (Fig. 8.9). Unlocking of the midtarsal joint, known as 'abductory twist', can occur during the last half of midstance should re-supination of the STJ fail to occur. The MTJ unlocks and causes the forefoot to abduct on the rearfoot, resulting in a less springy propulsive phase. The metatarsals. Forefoot loading during the contact phase should be observed from the anterior viewpoint (Fig. 8.8A-C). The fifth metatarsal head makes ground contact first, followed in sequence by the other metatarsals; the first metatarsal head is the last to make ground contact. At propulsion, the reverse should
Case comment 8.2 Given that the average time of contact is between 650 and 750 rns, information has to be rapidly absorbed by the observer. Practitioners may think there is an ankle equinus as a result of gait analysis only to find that on video replay the timing of heel lift is in correct sequence with the opposite foot.
172
SYSTEMS EXAMINATION
Figure 8.9 The foot should be viewed from the posterior aspect to determine subtalar joint and midtarsal joint position during midstance. The midtarsal joint offers a useful gauge to determine deformity due to abnormal pronation, leading to a medial shift in the talonavicular relationship. The lateral border may be very apparent as the foot pronates abnormally. The photograph shows moderate pronation with abduction at the midtarsal joint.
happen; the fifth is the first to leave the ground, followed in sequence by the others, with the first being the last to leave ground contact (Fig. 8.80). During propulsion, motion at the first MTPJ should be observed from the lateral side; ideally, the MTPJ should dorsiflex to approximately 70 0 • Toe position. Toes should be dorsiflexed at contact (Fig. 8.8A,B). Once the first metatarsal has contacted the ground on the medial side, all toes should be plantigrade (Fig. 8.8C). At propulsion the hallux should be the last to leave the ground. Any change in normal digital position
should be noted. The position of the digits during the stance phase is influenced by the intrinsic muscles Oumbricals and interossei) and the long and short flexors and extensors. The role of the intrinsic muscles is to provide transverse plane stability at the distal and proximal IPJs and prevent the toes from buckling under the effects of contraction of the extensors and/or flexors. Clawing of toes during gait can occur if the flexors have a mechanical advantage over the intrinsic and extensor muscles. Conversely, toe clawing can also occur if there is increased extensor muscle activity prior to heel lift.
ORTHOPAEDIC ASSESSMENT
Foot position/shape. When all the foot is in contact with the ground the position of the foot in relation to the midline of the body should be observed. Normally the foot should be slightly abducted (approximately 13°). If the foot is adducted (in-toeing) or excessively abducted (out-toeing) this should be noted together with whether the problem is bi- or unilateral. Foot shape can help inform us about function. Higharched cavoid feet (high STJ axis) produce a greater percentage of internal!external leg rotation, which can result in proximal symptoms in the lower limb. In contrast, low-arched flat feet (low STJ axis) produce increased frontal plane motion, which can result in symptoms in the foot (Green & Carol 1984). Muscle activity. The anterior view allows muscle activity to be observed (Fig. 8.10). Normal 'decelerator' muscle activity can be observed. Deceleration implies that the muscle resists joint movement by eccentric contraction; extensor tendons on the dorsum of the foot are active at contact because they decelerate the foot, prevent foot slap and allow the sole to contact the ground smoothly (Fig. 8.8A,B). Paralysis of the anterior muscle group will lead to a rapid collapse of the foot on to the ground and an audible slap. An example of a severe form of muscle group weakness is shown in Figure 8.11. The peronei, longus and brevis are difficult to identify during gait unless they show spasm. When this happens, and it is not common, the tendons stand out around the lateral malleolus (peroneus longus) and lateral foot (peroneus brevis). Propulsion. A lateral view of the first MTPJ at propulsion is useful to check whether the normal range of dorsiflexion (approximately 70°) is achieved. An alteration in gait at propulsion is often seen in hallux limitus/rigidus to avoid painful dorsiflexion. Furthermore, observation of the whole foot is necessary to assess whether a rigid lever is formed at propulsion and that the foot is not propulsing off an unstable hypermobile forefoot (a cause of first ray pathology). Swing phase. The foot pronates during early swing because the STJ provides additional dorsiflexion with pronation to aid ground clearance. Some neuromuscular conditions may
Muscle belly of extensor digitorum brevis Extensor digitorum .,,------f--c,+t-.c-+I longus
173
Tibialis anterior
Extensor
-::--t-- hallucis longus
Figure 8.10 Muscles on the dorsal aspect of the foot. It is important to observe muscle activity during gait. The contraction of the extensor and tibialis anterior muscles should be clearly seen (Fig. 8.8A,B).
prevent this from occurring and lead to the toes dragging across the ground, e.g. poliomyelitis. Signs of skin lesions over the digits may provide a clue that this is happening. Hip flexors and internal rotators contract to bring the leg forward. If the hamstrings are injured, the time spent in the swing phase will be reduced.
Abnormal gait patterns Gait can be affected in a variety of ways, leading to abnormal gait patterns. Some of the commonly encountered gait patterns are described below. Antalgic gait. This is usually due to a painful muscle, ligament or joint in the lower limb. Furthermore, a painful superficial skin lesion, e.g. verruca, can cause the patient to alter his gait so as to avoid weightbearing on the painful area of the foot. An antalgic gait may commonly be seen following an ankle sprain (lateral ligaments). Apropulsive gait. During the propulsive stage of gait the MTPJs should dorsiflex to approximately 70° and the hallux should be the last digit to leave the ground; if this does not occur, the gait is said to be apropulsive. An apropulsive gait may occur due to a variety of factors, e.g. hallux limitus/rigidus, abnormal pronation, unusual
174
SYSTEMS EXAMINATION
Figure 8.11 The flat-footed and abducted gait has been brought about by muscle paresis (weakness) in the lower leg. Extensive tests have shown no obvious diagnosis. The gait shows shuffle-waddling. There is marked abduction with bilateral ground contact for most of the stance phase. The left foot shows medial roll off as the leg prepares to move into swing.
metatarsal formula, excessive internal rotation of the leg. The foot may compensate for lack of propulsion by rolling off its medial border (Fig. 8.11), by propelling from a hyperextended (dorsiflexion) first IPJ rather than MTPJ or by an abductory twist. This is when the distal part of the foot twists outwards during propulsion. Whatever the cause, the foot is prevented from re-supinating during the later stages of midstance. However, once the heel lifts off the ground the effect of ground reaction, which prevented the re-supination, is reduced and the fore-
foot twists outwards in order to bring the foot into a more medial position for toe-off. Abnormal pronation. Abnormal pronation can be classified as excessive pronation and/or pronation occurring when the foot should be supinating. Signs of abnormal pronation during gait are excessive/prolonged internal rotation of the leg, eversion of the calcaneus, abduction at the midtarsal joint, an apropulsive gait and abnormal phasic activity of the muscles. Early heel lift. This may vary from the heel making no contact with the ground (toe walking)
ORTHOPAEDIC ASSESSMENT
to a relatively normal heel contact but an early heel lift. Heel lift should normally occur at the end of midstance prior to propulsion. An early heel lift can give rise to a bouncy gait. The most common cause is an ankle equinus. Limb-length inequality (LLI). One shoulder is usually lower than the other, and there may be a functional scoliosis. The determinants of gait are affected and the gait appears uneven. The foot of the shorter leg is usually in a supinated position and the foot of the longer leg abnormally pronates. Early heel lift may occur in the shorter leg and prolonged flexion of the knee of the longer leg. Trendelenburg gait. This is characterised by a lurching/waddling gait where the pelvis tilts to the affected side. Associated with congenital dysplasia of the hip and hip osteoarthritis (due to weak gluteus medius), Trendelenburg gait can present following Achilles tendon lengthening procedures and will remain as long as posterior leg muscle weakness persists. Painful knee joint. Avoidance of extension. Painful hip joint. It is commonly held in slight flexion, abduction and external rotation because this puts least stress on the capsule or inflamed synovial membrane. Walking speed and time spent on the involved hip is reduced, e.g. osteoarthritis, Perthes' disease and slipped capital femoral epiphysis. Foot drop or steppage gait. A high knee lift is produced during gait to ensure ground clearance of the affected limb. It is often associated with peroneal damage (Charcot-Marie-Tooth disease), weak tibialis anterior or poliomyelitis. Circumducted gait. A CVA victim has the characteristic features of unilateral limb weakness and will circumduct (rotate the leg in an arc) and flex the elbow and hand towards the body. Movements are made slowly to maintain balance. Jerky movements suggest muscle coordination problems; the nature of upper and lower motor neurone deficits are described in Chapter 7. Scissoring gait. The legs cross the line of progression during gait in cerebral palsy. Circumduction is necessary in order to produce forward motion. Dystrophic/atrophic gait. An exaggerated alternation of lateral trunk movements with an exag-
175
gerated elevation of the hip suggestive of the gait of a duck or penguin is seen in Duchenne's muscular dystrophy (Sutherland et aI1981). Festinating gait. Small accelerating shuffling steps are taken often on tip-toe. This gait pattern is typically associated with Parkinson's disease. Ataxic gait. This condition produces an unstable poorly coordinated wide base of gait pattern. It is primarily seen in patients with cerebellar pathology. Helicopod gait. The feet describe half-circles as they shuffle along during contact and early midstance phase. This condition is seen frequently in hysterical disorder.
NON-WEIGHTBEARING EXAMINATION The prime purpose of the non-weightbearing examination is to undertake an assessment of the joints and muscles of the lower limb. Information from this part of the examination may explain the cause of a gait abnormality or the patient's presenting problem. For example, a foot may in-toe as a result of an osseous and/ or soft tissue problem of the leg; the purpose of the non-weightbearing examination is to establish which is most likely. A flat couch is required for the patient to lie on. The patient should feel comfortable and relaxed and should not wear restrictive clothing. Non-weightbearing examination involves an assessment of the following: • • • • • • • •
hip knee ankle subtalar midtarsal metatarsals metatarsophalangeal joints (MTPJs) digits (proximal and distal interphalangeal joints - IPJs) • alignment of the lower limb.
Hip examination The hip joint is both a mobile and stable joint. Stability is provided by the depth of the acetabulum, strong capsule, capsular ligaments and sur-
176
SYSTEMS EXAMINATION
rounding muscles. Mobility occurs in all three body planes. The primary presenting problem is often hip pain (coxodynia), This is felt deep in the groin, whereas pain on the outside of the femur is often referred pain from the spine. A hip problem can occasionally result in pain being referred (via the obturator nerve) to the knee. A patient who cannot accurately localise pain in the knee should be suspected of having a disorder of the hip. The main cause of hip pain is osteoarthritis, a particularly common condition in the elderly. An X-ray of the hip should be considered if confirmation of a disease process is necessary or diagnosis unclear, e.g. osteoarthrosis, Perthes' disease. It is not usually necessary to examine every patient's hip. The hip should only be examined if the patient complains of discomfort or pain in the area and/or gait analysis reveals an abnormality which affects normal pelvis and thigh/leg motion. Observation of the hip for gross deformity, muscle wasting, oedema, contusion and scar will provide valuable information about potential or past pathology. In addition, palpation of the hip region for joint, muscle pain/tenderness or bursitis (e.g. greater trochanter bursitis due to overuse, weakness of gluteus medius on the opposite side or LLI) is helpful. Where a hip examination is indicated, a series of tests on the hip joint itself in addition to the muscles acting upon it is undertaken.
pelvis while the other hand holds the opposite leg just above the anterior knee and moves the leg towards the body to the point of resistance. Loss of sagittal plane motion may be due to pain, femoral nerve entrapment or effusion in the hip joint as the anterior ligaments (iliofemoral and pubofemoral) will be under greater tension and resistance than usual. Any asymmetry should be noted. Frontal plane. To assess abduction and adduction at the hip the patient lies supine and the practitioner holds the leg just below the anterior knee. The leg with the knee extended is moved across the opposite leg (adduction) and then brought back and abducted. The pelvis should be stabilised during this assessment by placing a hand on the opposite iliac crest. There should be less adduction than abduction at the hip. Tightness of the adductors on abduction can lead to a scissors-type gait: this is when one or both legs have a tendency to cross over during gait and can be seen with cerebral palsy. Transverse plane. Internal and external rotation of the lower limb is essential for normal gait. Ideally, the total range of transverse plane motion in an adult should be 90°, comprising 45° internal and 45° external rotation. Females tend to show more internal rotation than males (Svenningsen et al 1990). The range of transverse plane motion at
Hip joint tests
Assessment of hip motion should be undertaken in each of the three body planes - sagittal, frontal and transverse. Sagittal plane. To ensure forward progression during gait, sagittal plane motion at the hip is necessary. Ideally, there should be approximately 120-140° of flexion and 5-20° of extension, although not all of this is necessary for gait. To assess hip flexion the patient is placed supine on a firm, flat couch. The practitioner holds the leg firmly and flexes the hip by pushing the leg towards the body until resistance is met (Fig. 8.12). To assess extension the patient is placed in the prone position. The practitioner places one hand on the posterior superior iliac crest to stabilise the
Figure 8.12 The patient should be asked to draw the leg towards the stomach as depicted in the photograph. The hip is flexed to its limit against the abdomen. Thomas's test should be considered at the same time by looking for contralateral lifting.
ORTHOPAEDIC ASSESSMENT
the hip decreases with age and the DOM changes from symmetry to more external than internal rotation. To assess transverse plane rotation the patient lies in a supine position. The hip and knees are flexed and the leg is moved medially and laterally as one would the arms of a clock. A gravity goniometer can be used to assess the range of motion (Fig. 8.13). Asymmetry in the DOM should be noted. For example, a patient who shows 70° internal rotation and only 20° external rotation has an internally rotated femur which will affect normal lower limb function and may result in abnormal pronation at the subtalar joint. The test can be repeated with the patient in the same position but with the hip and knees
extended. The practitioner may note a difference in the ROM and DOM at the hip when the knees are flexed compared to when they are extended. It was thought that this technique could be used to detect the presence of torsion (bone influence) or version (soft tissue influence). Torsion was said to exist if there was no difference between the ROM and DOM at the hip with the knees flexed and extended and version if there was a greater ROM when the knees were flexed. It was considered important to make a distinction as torsion cannot be treated conservatively while version can. This concept, while plausible, is not consistent with bone torsion measurement and is open to misdiagnosis. However, it is important when
B
A Figure 8.13
rotation
177
The hips are in a flexed position A. A gravity goniometer is used to assess the amount of internal femoral B. A gravity goniometer is used to assess the amount of external femoral rotation.
178
SYSTEMS EXAMINATION
undertaking an assessment of the muscles around the hip to see if there are any soft tissue contractures, which may be responsible for limiting motion. Contracture of capsular structures of the hip will limit hip movement when these structures are on-stretch (hip extended), whereas contracture of the medial hamstrings will limit external hip rotation with the hip in a flexed position. Scouring/circumduction test. This test is used to assess QOM and joint congruency in patients complaining of groin pain. The hip is flexed and adducted and the practitioner rotates the hip to test for any crepitations. If pain is provoked during this manoeuvre with the hip internally rotated a lesion of the acetabular labrum should be suspected. A posterolateral force applied to the hip will test the integrity of the posterior/lateral hip capsule. Patrick's or faber's test (flexion abduction external rotation). The patient lays supine with one leg
straight. The other knee and hip are flexed so that the heel is placed on the knee of the straight leg. The knee is then slowly lowered into abduction. Gentle pressure is applied to the flexed knee while the opposite hand stabilises the pelvis over the opposite anterior superior iliac spine. This test stresses the medial hip capsule by placing an anteromedial force on the hip, the integrity of the iliofemoral! pubofemoral ligaments and also assesses for sacroiliac discomfort. Sacroiliac joint provocation test. Patients who experience pathology of the sacroiliac joint may complain of pain in the region of the hip. It is therefore important to be able to exclude pathology in the sacroiliac joint. To isolate and test this joint the practitioner places her hands on the anterior superior iliac spines of the pelvis and presses down firmly and evenly to compress the joint and stress the sacroiliac ligaments. The test is positive if the patient experiences unilateral pain in the abdominal-groin, gluteal region or the leg. Hip muscle tests Young's test. A taut tensor fasciae latae causes the knee and hip to flex. By abducting the lower limb, tension on the tensor fasciae latae is reduced
and any flexion deformity should disappear. A tight tensor fasciae latae may be the cause of an apparent limb length discrepancy. Thomas's test. Iliopsoas consists of psoas major, psoas minor and iliacus (the prime flexors of the hip). Thomas's test is used to rule out the presence of iliopsoas contracture. If a flexion deformity exists the affected leg will flex at the knee (see Fig. 8.12) (Case comment 8.3). Furthermore, the femoral nerve can be irritated by a taut iliopsoas group. Damage to the nerve will lead to weakness of the quadriceps, as well as loss of sensation on the anterior and medial aspects of the leg (Case comment 8.4). Ely's test. This test is used to assess hip flexor (rectus femoris) tightness or contracture. The patient lies prone and the knee is slowly flexed as far as possible until the heel comes close to the buttocks. Observe the buttock/hip during this manoeuvre. The point at which the buttock rises off the couch on the tested side indicates the degree of hip flexor tightness. Ober's test. This test is designed to assess for iliotibial band contraction or tightness. The patient lies on his side and the outer limb with the knee extended is moved anteriorly and then adducted towards the couch (Fig. 8.14A). This stretches the lateral structures, primarily the
Case comment 8.3 Thomas's test: while the patient flexes the hip, the practitioner must observe the opposite (contralateral) thigh for any sign of elevation. The lumbar spine must lie flat. If the iliopsoas muscles are tight, the contralateral hip will rise as the ipsilateral hip will force the lumbar spine against the COUCh. Fixed flexion will cause an apparent LLI.
, - - - - - - - - -....._ - - _ . _ - - - - - - - Case comment 8.4 The obturator nerve arises in the psoas major and crosses the hip joint, exiting through the obturator foramen. If this nerve is injured in the hip region, e.g. due to a slipped capita femoris epiphysis, knee pain may result. Where knee pain exists, hip pathology must always be ruled out.
ORTHOPAEDIC ASSESSMENT
Figure 8.14
179
A. Ober's test identifies resistance in the tensor fascia/iliotibial tract B. Assessment of the external rotators. Muscle strength can be gauged by resisting external rotation C. The patient is asked to bring the knees together against resistance. This tests adductor strength.
A
B
C
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SYSTEMS EXAMINATION
iliotibial band. A modified form of the test separately tests the short fibres of the knee; this is achieved by flexing the knee and repeating the manoeuvre. Piriformis test. With the patient lying on his side, the hip and the knee are flexed to 90°. The examiner places one hand on the pelvis for stabilisation and with the other hand applies pressure at the knee, pushing it towards the couch. This puts the piriformis muscle on tension. If tightness of the piriformis muscle is impinging on the sciatic nerve, pain may be produced in the buttock and also down the leg. Also, in this position the strength of the external rotators of the hip can be tested by asking the patient to externally rotate the hip against resistance (Fig. 8.14B). Adductor strength test. The adductors have their insertion on the medial side of the femur along the linea aspera. The adductor muscles are important during the swing phase, stabilising the contralateral side of the hip against the pelvis as the leg swings forward. Adductor strength can be tested as in Figure 8.14C. Gracilis, a partial adductor, rotates the femur on the hip. As it shares some of the function of the adductors, it can be examined with them. However, this muscle crosses the knee and lies between the sartorius and semitendinosus on the medial aspect of the knee. The knee should be extended to include the action of gracilis, but flexed to remove its influence. Abductor strength test. The abductors include the gluteus medius and minimus as well as tensor fasciae latae. Together they act through the iliotibial tract. Abductor strength is best assessed when the subject lies on his side. The patient should raise the upper leg away from the couch against gravity and resistance. Trendelenburg's test (Stork test). This tests the stability of the hip and the ability of the hip abductors to stabilise the pelvis on the femur. The patient stands on one leg with the other knee flexed; the pelvis should tilt upwards or stay level on the side of the lifted leg. A positive Trendelenburg sign occurs when the reverse happens: the pelvis tilts downwards, indicating weak glutei. Osteoarthritis of the hip can produce a positive Trendelenburg sign.
Laseque's (straight-leg-raise) test. This test will provoke pain in patients with hamstring muscle inflexibility, severe hip pathology and also tests mobility of nerve roots L4 to 52. Where no pathology is present the leg should make an angle of 70° to the supporting surface (Gajdosik et al 1993, Kendall et al 1993). There is no significant difference in hamstring flexibility between males and females (Gajdosik et al 1990).
Functional tests If the patient's pain has not been reproduced
during formal examination, then functional tests should be performed. A single leg squat can be used to assess pelvic control. Abnormalities of excessive lateral or anterior tilt may be noted. Stepup or step-down tests may also be useful.
B
Figure 8.15A,B A. Normal knee anatomy: (1) anterior cruciate (2) posterior cruciate (3) meniscus (4) collateral ligament (5) cartilage (6) ligamentum patellae surrounding patella (7) tibial tubercle B. Diagrammatic representation of the joint margin.
ORTHOPAEDIC ASSESSMENT
Knee examination The knee joint is the largest joint in the body. It is a complex structure which is comprised of the patellofemoral and tibiofemoral joints. The knee should be examined if dysfunction is observed during gait and/ or the patient complains of knee discomfort/pain. To make a comprehensive assessment of knee function a detailed history is required. It is important that the practitioner establishes whether knee pain/discomfort is due to a primary problem affecting the knee, e.g. meniscus tear, or to compensation for a problem
elsewhere, e.g. abnormal pronation causing instability and damage to the knee. Figure 8.15 illustrates the anatomy of the knee joint and the knee joint margin. The knee joint can be compared to a boiled egg lying on a plate; the configuration of an oval femoral surface on a flat tibial plateau allows great mobility. During gait it is important that the knee is stable; the cruciate and collateral ligaments, the menisci and the iliotibial band and sartorius muscles provide most of the stability. The patella forms part of the knee joint; it articulates with the anterior surface of the inferior
C Figure 8.15C
181
Photograph of the joint margin corresponding to B. (Fig. 8.15A,B on facing page.)
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SYSTEMS EXAMINATION
end of the femur. It acts as a sesamoid as described earlier and provides a key mechanical advantage, increasing the moments of force applied through the ligamentum patellae on to the tibial tubercle. The history should be followed by a comprehensive clinical examination of the knee joint and its associated structures. In view of the number of structures involved, assessment needs to be approached in a systematic manner. The key feature of the knee examination is that each structure that may be injured must be examined. The following scheme of assessment is suggested: • • • • • • • • • •
observation palpation patellofemoral joint tests tibiofemoral joint motion tibiofemoral joint stability integrity of internal knee structure muscle testing Q angle functional tests laboratory tests.
Observation
Prior to formal examination the knee should be observed for: • Gross deformity (genu valgum/varum, enlarged or abnormal position of tibial tubercle). • Patellar position (squinting, fisheye or outward facing, patella alta, patellar tilt or rotation). • Patellar size (small patella unstable in femoral groove, susceptible to subluxation/ dislocation). • Oedema - the presence and site of swelling in the knee should be noted (Case comment 8.5). Swelling of an extreme nature can be associated with bursitis, acute synovitis, tearing of the menisci, rheumatoid arthritis (Baker's cyst) or osteoarthritis. Spontaneous swelling is usually caused by cruciate or meniscus injury or haemarthrosis following trauma. • Tonic muscle spasm (hamstrings) secondary to intra-articular/ extra-articular pain.
Case comment 8.5 A to-year-old male developed a tender area on the anterior aspect of his knee during activity. The site of the tibial tubercle was shown to have been damaged by force from the traction of ligamentum patellae, leaving clinically a hot swollen prominence. The condition was Osgood-Schlatter's disease, a common example of a traction apophysitis. Examination may reveal an old unilateral or bilateral condition typified by an enlarged tubercle.
• Muscle wasting (quadriceps femoris, particularly vastus medialis). Often associated with anterior knee pain, osteoarthritis, rheumatoid arthritis and Osgood-Schlatter's disease. • Bruising (trauma). • Scars (site and size will provide evidence of type/ extent of surgery). Palpation
Systematically palpate the knee to localise areas of pain/ tenderness and thereby isolate the structures involved: • Palpate for warmth (inflammatory joint disorder). • Palpate for oedema (generalised/localised). • Palpate joint line medially /laterally for joint, meniscal pathology and anteriorly for coronary ligament pathology. • Tendons crossing the knee joint: medially (semitendinosus / semimembranosus); laterally (biceps femoris, iliotibial band); and anteriorly (patellar tendon). • Patellar: tenderness superior pole (rectus femoris tear or bipartite patella); pain in body of patellar (fracture following trauma); pain inferior pole of patellar (Sinding-LarsenJohansson syndrome); infrapatellar fat pad palpated for tenderness - this fat pad can become impinged between the patellar and femoral condyle following forced extension of the knee (Hoffa's syndrome); however, chronic fat pad impingement (aka infrapatella bursitis) occurs more frequently.
ORTHOPAEDIC ASSESSMENT
• Popliteal fossa (Baker's cyst, popliteus bursitis, fabella). • Tender, enlarged tibial tubercle (OsgoodSchlatter's disease). • Local oedema. • Bursae (suprapatellar - between quadriceps tendon/femur; prepatellar - between front of patellar/ skin; infrapatellar - between patellar tendon/proximal tibia; pes anserine - under tendinous insertion of gracilis, semitendinosus and sartorius muscles). • Soft tissue lumps such as lipoma can also be found around the knee. Patellofemoral joint tests Ballottement test (patellar tap test). This is used to test for moderate intracapsular swelling. Squeeze excess fluid out of the suprapatellar pouch, place tips of the thumb and three fingers on the patella, and jerk it quickly downwards. A floating sensation of the patella over fluid or a click indicates the presence of an effusion. Wipe test (fluid displacement test). This is used to test for slight to moderate intracapsular swelling. First, evacuate the suprapatellar pouch of fluid; then stroke the medial side of the patellar. A wave of fluid will bulge on the lateral side of the joint. Stroke the lateral side and observe the medial side of the joint for fluid movement. Apprehension test. The patella is manually displaced laterally. If the patient shows signs of apprehension by contracting the quadriceps, this is a positive indication of a subluxing/dislocating patella. 50 :50 test. Displacement of the patella greater than 50% of its width both medially and laterally indicates hypermobility (supported by the Beighton scale). Clarke's test. With the patient supine the practitioner places one hand proximal to the superior pole of the patella and asks the patient to contract the quadriceps. This test is used to detect anterior knee pain, and used to be a popular test for the diagnosis of chondromalacia patellae; however, chondromalacia patella can only really be diagnosed on arthroscopic examination.
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Tibiofemoral joint motion
The main motion at the knee occurs in the sagittal plane; this is important for forward progression during gait. Ideally, the knee should flex to approximately 135°; the thigh muscles restrict further motion. The amount of sagittal plane motion can be measured with a protractor or tractograph. The amount of extension available is minimal (0-10°). Forced extension of the knee will test the posterior capsule. The knee should extend and lock without pain, with the patella in the centre of the knee. Postural extension beyond 10° is known as genu recurvatum and is indicative of lower limb dysfunction or flexed trunk posture (Riegger-Krugh & Keysor 1996).
Tibiofemoral joint stability Frontal plane. The lateral and medial ligaments of the knee provide stability in the frontal plane. There should be no or limited frontal plane motion at the knee. Frontal plane motion is normally only available to a child under 6 years of age. Lateral collateral ligament stress test (varus stress test). A lateral stress test is used to assess
the lateral collateral ligaments. With the patient supine, the knee is flexed to 30° so the joint is unlocked during the test. The practitioner places one hand on the medial side of the lower end of the femur and the other on the lateral side of the upper end of the tibia. The practitioner then pushes with both hands in an attempt to 'break' the knee by stressing the lateral collateral ligament. Palpation of the lateral collateral ligament (which is deep to biceps femoris) can be made easier using the 'figure-4' position. The patient is seated with the hip maximally externally rotated, the knee flexed to 90° and the foot rested on the top of the distal thigh of the other leg. Medial collateral ligament stress test (valgus stress test). The medial collateral ligament can
then be stressed by placing the hand in the opposite position. Motion at the knee during these tests indicates weak collaterals and poor knee stability. The medial collateral ligament is more commonly damaged (e.g. football/rugby players). The lateral
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SYSTEMS EXAMINATION
collateral ligament is less commonly damaged (e.g. ice hockey players). Integrity of internal knee structures
Assessment of anterior and posterior cruciate ligaments tests knee stability in the sagittal plane. There are two cruciate ligaments within the knee joint: anterior and posterior. Their purpose is to prevent the knee joint from 'opening up'. Drawer test. To assess the anterior cruciate ligament the patient lies supine with the knee flexed to 45° and the foot flat on the couch. The practitioner sits on the foot and grasps the upper end of the tibia and pulls it forward to stress the anterior cruciate ligament. The posterior cruciate is examined by reversing the manoeuvre. This test is known as the drawer test because the action is like opening and shutting a drawer (Fig. 8.16A). More than 2-3 cm displacement of the tibia is considered abnormal and may be painful; excessive movement suggests tearing of these structures. The Lachman's test specifically tests the anterior cruciate ligaments. The knee is flexed to 25° and the tibia is pulled forward while the knee is externally rotated. If there is displacement of the tibia this is indicative of a weak anterior cruciate ligament. A positive sign is indicated by a forward translation of the tibia with a mushy/soft end feel. The pivot shift test will also assess the anterior cruciate ligaments. With the knee in full extension and the tibia internally rotated, a valgus force is applied to the knee. In an anterior cruciate deficient knee, the condyles will be subluxed. The knee is then flexed, looking for a 'clunk' of reduction, rendering the pivot shift test positive. McMurray's test. This is used to detect meniscus tears. The medial meniscus is most likely to tear because it has less flexibility as it is attached to the capsule. The McMurray test is also designed to seek out any loose bodies by detecting crepitations and clicking (Fig. 8.16B,C). There may be a history of knee locking due to tonic spasm of the hamstrings in order to protect the joint. The patient lies supine with the knee and hip flexed to 90°. The practitioner grasps the sole of the foot with one hand; the other should be placed around the knee so that the joint line can be palpated. By moving
A
B
c Figure 8.16
Knee joint examination A. Drawer test requires the tibia to be push-pulled against the femur B. McMurray's rotation test with the knee flexed and the leg externally rotated C. McMurray's rotation test with the knee flexed and the leg internally rotated.
ORTHOPAEDIC ASSESSMENT
the foot the tibia is externally rotated and a valgus stress is applied. A positive test will elicit a 'popping' or 'snapping' sound or sensation. The test is repeated with internal rotation and a varus stress for the lateral meniscus. Ensure that snapping and clicks due to normal tendon movement over prominences are not misdiagnosed as pathological lesions. Apley's compression test. The patient lies prone and the knee is flexed and the foot grasped. The practitioner creates a compression at the knee joint while producing a rotation movement. A noisy and painful response suggests meniscus damage.
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action with the quadriceps and a functional equinus at the ankle joint. The 90: 90 test is performed with the patient supine. The knee and hip are flexed to 90°. The practitioner holds the leg and extends the knee until resistance is met. If the knee can be fully straightened or to within 10°, then the hamstrings are within normal limits. If the leg can only be partially extended it indicates tight hamstrings. Any asymmetry should be noted. To assess whether this is due to a tight biceps femoris or semitendinosus, stretch can be placed on the biceps femoris muscle by medially rotating the extended leg and on the semitendinosus by laterally rotating the leg (Fig. 8.18).
Muscle testing Quadriceps. The practitioner should inspect the tone of the quadriceps. Wasting of the medial vastus in particular may occur as a result of knee dysfunction. A tape measure can be used to assess muscle bulk in this area and monitor any change as a result of treatment (see Fig. 8.7). The circumference of both legs should be measured at a standard distance of 10 cm above the superior pole of the patella. The rectus femoris muscle is a weak flexor of the hip but a powerful extensor of the knee. As part of the quadriceps group of muscles, rectus femoris is an important stabiliser of the knee, in conjunction with the vasti, and is needed to swing the leg forward in gait. Pain at its insertion (anterior inferior iliac spine) can arise with a strong kicking action. Examination of the rectus femoris muscle is undertaken with the patient sitting on the edge of the couch with the knees flexed. To assess the strength of this muscle the patient is asked to extend the knee while the practitioner attempts to resist this active motion (Fig. 8.17). Hamstrings. The tone of the hamstrings should be inspected. From an extended knee position the strength of the hamstrings is tested by asking the patient to flex their knee (push down) against resistance. The 90: 90 test is used to identify tightness and contracture of the hamstring muscle group. Tight hamstrings may cause knee flexion, creating an inefficient antagonist
Figure 8.17 Rectus femoris is tested by extending the knee against resistance.
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SYSTEMS EXAMINATION
Functional tests If the patient's pain has not been reproduced
during formal examination functional tests such as squat,lunge, hop, step-up or step-down should be performed. Laboratory tests
X-rays (anteroposterior and skyline views) may be requested to gain a full picture of the extent of osseous damage to the knee and to rule out osteoarthritis, loose bodies, a fragmented patella or bipartite patella. Ultrasound or magnetic resonance imaging (MRI) will demonstrate thickening/swelling around a tendon, the presence of any tendon tears or degeneration and meniscal damage. Assessment of joint aspirate will rule out haemorrhage, in, e.g. haemophilia, or pus, in, e.g. infective arthritis. Arthroscopy can be combined with surgical exploration of the joint.
Tibia/fibular examination
Figure 8.18 90 : 90 test. The leg can be laterally and medially rotated to identify specific areas of tightness. The photograph shows the leg laterally rotated to identify tight medial hamstrings.
Qangle
The 'Q angle' is the position the patella adopts in relation to the direction of pull of the quadriceps tendon. A line is drawn from the ASIS to a line bisecting the patella. If the angle of this line to the bisection of the patella is greater than 15° the patient is said to have a high Q angle. This suggests medial displacement of the patella and is often associated with greater than normal internal rotation and anterior knee pain.
The tibiofibular segment should be examined for soft tissue swelling. Bilateral swelling suggests a systemic rather than local cause. Unilateral leg oedema in women over 40 years is a common sign of intrapelvic neoplasm. Local swelling is common over inflammatory lesions and stress fractures. Local bone swelling is suggestive of an old fracture or neoplasm (e.g. osteoid osteoma). Multiple or single exostoses occur in the tibia in diaphyseal aclasia. Thickening of the ends of the tibia is seen in osteoarthritis and rickets. The tibiofibular segment should be examined for areas of tenderness. An enlarged and painful tibial tuberosity can be seen in Osgood-Schlatter's disease, tenderness over the proximal/lateral area of the tibia is associated with Brodie's abscess or osteitis, whereas pain in the region of the head of the fibular can be due to proximal tibiofibular joint osteoarthritis. Anterior pain between the tibia and fibular following trauma is seen in anterior tibial compartment syndrome, whereas pain directly over the anterior tibial border is associated with tibial stress fracture. Tenderness in the region of
ORTHOPAEDIC ASSESSMENT
the medial border of the tibia can be associated with medial tibial stress syndrome. Tenderness over the inferior tibiofibular joint may be associated with lateral ligament injury and may cause anterior ankle pain. Tenderness in the back of the calf may be associated with a ruptured plantaris tendon syndrome, whereas pain over the tendo calcaneus may be suggestive of a partial or complete rupture. With the patient prone, Thomson's test can be performed. The calf is squeezed. If no ankle plantarflexion occurs, a complete rupture is indicated. The frontal plane alignment of the tibia should be determined because tibial deformity can influence foot function. This is best performed in the supine position by bringing the legs together and observing the relative distance between the knees and malleoli. A greater distance between the knees is seen in tibial varum. Tibial varum is generally more common than tibial valgum. In the largest normative study, Astrom & Arvidson (1995) reported a mean of 6° of tibial va rum; therefore, a slight tibial varum is considered normal. An excessive tibial varum, however, can lead to a range of lower limb conditions with the development of pathology theoretically dependent on the STJ's ability to compensate. Unilateral overuse injuries are more likely to exhibit larger tibial varum on the affected side (Tomaro 1995). The eight-finger test can also be used to estimate the degree of frontal plane bowing of the tibia. All eight fingers are placed along the anterior border of the tibia and their alignment compared. Sagittal plane bowing (sabre tibia) and general tibial thickening as seen in Paget's disease should not be overlooked (Fig. 8.19). It is also important to assess for any transverse plane deformity of the tibia, as this can influence foot function. Medial tibial torsion is associated with flat feet and intoeing deformities (Thackery & Beeson 1996), whereas a lateral torsional deformity of the tibia is seen in pes cavus. With the patient supine and knees flexed and the soles of the feet on the couch, the relative lengths of the tibiae should be assessed by comparing the heights of the knees (Skyline/Allis test) or tibial tuberosities.
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Figure 8.19 Patient with severe bowing associated with Paget's disease, 'sabre tibia' affecting patients in the sixth/seventh decade of life. Deformity occurs in the sagittal as well as the frontal plane.
Ankle examination Inman (1976) regards the ankle as a two-joint system comprising the talocrural joint (TCD and the subtalar joint (STD. Motion of the foot is primarily controlled through this joint complex, but the whole proximal segment also relies upon the TCJ and STJ working in concert. Elftman (1960) considered the midtarsal joint to be the third member of the ankle complex. In addition, Brukner & Kahn (1993) consider the inferior tibiofibular joint to be part of the ankle joint complex. The inferior tibiofibular joint is a syndesmosis supported by the inferior tibiofibular ligament. A small amount of rotation is present at this joint. Each of these joints will be considered separately for examination purposes but functionally they should be considered together. Coalitions between the joints making up the ankle complex may be present. The two most common involve the talocalcaneal (medial and posterior facets) and the calcaneonavicular (Kulik & Clanton 1996). Other types may occur but are quite rare. The coalition may be fibrous, cartilaginous or osseous. Fibrous coalitions permit some motion whereas cartilaginous and osseous coalitions produce little motion but more symptoms. Tonic spasm of the peronei is a common finding with tarsal coalitions. X-rays are necessary to diagnose a synostosis (osseous coalition).
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SYSTEMS EXAMINATION
Talocrural joint The trochlear surface of the talus articulates with the inferior surface of the tibia to form the talocrural joint. The medial and lateral malleoli provide additional articulations and stability to the ankle joint. The talocrural joint is a triplanar joint but, because of the position of its axis and the shape of the joint surfaces, its main motion is in the sagittal plane. The lateral curvature and radius of the trochlear surface of the talus has been found to be variable - the longer its radius, the less dorsiflexion (Barnett & Napier 1952). During midstance there should be at least 100 of dorsiflexion at the ankle in order to allow the leg to move over the foot. The body compensates for a lack of ankle dorsiflexion at the knee and/or subtalar and midtarsal joints. The STJ has less available sagittal plane motion than the TCL but if necessary the STJ will increase the amount available if there is insufficient motion at the TCJ. In addition, the knee can hyperextend (genu recurvatum) as a way of compensating for an ankle equinus. Assessment of TCJ range of motion, stability, strength, palpation for tenderness, grading of ligamentous injury and proprioception are important parts of the ankle joint assessment. Joint motion. The passive range of TCJ plantarflexion and dorsiflexion should be assessed and compared for each limb. Ankle equinus is traditionally defined as less than 100 of dorsiflexion at the TCJ, although some practitioners suggest that less than 50 dorsiflexion leads to abnormal compensation. It may arise from soft tissue or bone abnormalities of an acquired or congenital nature. Assessing sagittal plane motion at the TCJ is difficult. It can be assessed either weightbearing or non-weightbearing. If assessed non-weightbearing the patient should lie in a prone or supine position with the knee extended and the foot and ankle free of the end of the couch. The practitioner holds the foot in a neutral position with one hand, places the other hand on the sole of the foot and dorsiflexes the ankle (Fig. 8.20A). If subtalar joint pronation is allowed to occur during the examination a falsely elevated
dorsiflexion value will result (Rome 1996a, Tiberio et aI1989). The force applied by the practitioner to produce TCJ dorsiflexion can vary; this will have an effect on the result. A tractograph can be used to assess the range of motion but the practitioner may find it difficult to use, while at the same time keeping the foot in a neutral position (Fig. 8.20B). In addition the intra- and interobserver reliability of non-weightbearing TCJ dorsiflexion measurements using a tractograph is questionable (Rome 1996b). A tight soleus and/or gastrocnemius may prevent TCJ dorsiflexion. To differentiate between the two the amount of dorsiflexion with the knee extended and flexed should be measured. With the knee flexed the tendons of gastrocnemius which cross the knee are released from tension and as a result a tight gastrocnemius should not affect TCJ dorsiflexion. If the amount of dorsiflexion is still reduced when the knee is flexed the cause is likely to be soleus (Fig. 8.20C). A bony block (osteophytes on distal! anterior tibia) can also limit "rCJ dorsiflexion with the knee flexed; however, the tendo Achilles in this case will feel slack. Assessment of the TCJ end-of-ROM is useful. Soft tissue limitation will result in a springy endfeel, whereas limitation resulting from a bony block will be abrupt. More consistent results have been achieved when sagittal plane motion is assessed with the patient weightbearing. The patient stands facing a wall with a distance of approximately 0.5 m between the patient and the wall. One leg, with the knee in a flexed position, is placed in front, approximately 30 cm from the wall. The other leg is placed behind the forward foot with the knee extended and the foot held in a neutral position. The patient leans towards and places both hands on the wall and is asked to move his body towards the wall. In order to do this the patient must dorsiflex the ankle of the limb furthest from the wall. The amount of dorsiflexion can be measured with a tractograph (Fig. 8.200). Stability. By moving the TCJ in all three planes the ligaments can be stressed and any tenderness noted. There should be little or no
ORTHOPAEDIC ASSESSMENT
A
C
B
D
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Figure 8.20 Ankle joint dorsiflexion A. Non-weightbearing assessment of ankle joint dorsiflexion with the knee extended and the foot in the neutral position. Restriction of motion may be due to tight gastrocnemius, soleus or bony block B. A tractograph is used to measure the amount of dorsiflexion C. Non-weightbearing assessment of ankle joint dorsiflexion with the knee flexed and the foot in a neutral position. Restriction with the knee flexed due to a bony block or tight soleus D. Assessment of ankle joint dorsiflexion weightbearing.
displacement in the frontal plane and the patient should find the movement pain-free. Tenderness from the lateral ligaments (calcaneofibular and talofibular) should be noted before stressing the joint at the extreme ends of inversion and eversion. The anterior joint line should be pressed upon firmly at the tibial plafond. The talus may have less stability if the inferior transverse tibiofibular ligament is affected as this holds the distal end of the tibia and fibular within the ankle mortise.
Stability in the sagittal plane can be tested by applying a forward and then a backward push on the TCJ while the knee is flexed and the foot is in contact with the examining couch. This is the drawer test and should reveal minimal positional change and no discomfort. This test assesses the integrity of the anterior talofibular ligament. The talar tilt test will assess the integrity of the calcaneofibular ligament laterally and the deltoid ligament medially. With the patient supine the calcaneus is grasped and moved medially and
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SYSTEMS EXAMINATION
laterally. The medial and lateral movement of the talus and calcaneus is assessed in relation to the tibia and fibular. Stress X-rays using a German system known as TELOS allows the ankles to be compared (Fig. 8.21). Anterior-posterior shift and lateral stress views can be taken. The procedure is performed under local anaesthesia using a common peroneal nerve block; it provides a reproducible method to determine ankle stability. Functional tests. These tests can be a valuable aid to diagnosis. The lunge test (patient lunges forward while standing) assesses weightbearing ankle dorsiflexion and helps in the diagnosis of anterior impingement syndromes. The singlelimb heel-raise test may be used to aid the diagnosis of tibialis posterior dysfunction syndrome (TPDS). If the manoeuvre induces pain in the region of the tubercle of the navicular extending to the posterosuperior border of the medial malleolus and along the posteromedial tibial border with the calcaneus failing to invert a partial or complete tear of the tendon is indicated. The patient with TPDS will also present with a severely pronated foot. Functional tests such as single-leg standing and hopping can be used to reproduce a patient's pain in other causes of ankle pain. The posterior aspect of the talus should be palpated while the ankle is in a plantarflexed position. Stieda's process may become irritated, or fracture if extra-long, or may appear as a separate bone (os trigonum) and become transiently irritated. The pain is deeper than with soft tissue problems such as a tender Achilles tendon. Strength. Both active movements of ankle plantarflexion/ dorsiflexion, inversion/ eversion and resisted movements of eversion should be assessed using the Medical Research Council system. Grading of ligamentous injury. The lateral ankle ligaments are more commonly damaged than the medial (deltoid) ligament. In the typical inversion and plantarflexion injury, the three parts of the lateral ligament are usually damaged in order, depending on the severity of the sprain: the anterior talofibular ligament (ATFL) followed
Figure 8.21 TELOS: lateral ankle stress test under local anaesthesia (reproduced by courtesy of Fifth Avenue Hospital, Seattle).
by calcaneofibular (CFL) and, finally, the posterior talofibular ligament (PTFL). Complete tear of all three ligaments is usually associated with an ankle fracture. Lateral ligament injuries are divided into three grades: • grade I = minor ATFL tear with pain but no laxity • grade II = painful if stressing ligament with laxity but firm end-point • grade III = gross laxity without discernible end-point. To isolate the specific structure(s) damaged following an ankle injury a number of areas around the ankle should be palpated for tenderness (Table 8.7).
ORTHOPAEDIC ASSESSMENT
Proprioception. Single-leg standing with eyes closed may demonstrate impaired proprioception compared with the uninjured side. Investigations. X-rays (anteroposterior mortice, lateral and oblique views) should be performed after ankle sprains in cases where instability is present or acute bony tenderness is present on the malleoli or the medial or lateral dome of the talus. Ankle X-rays must include the base of the fifth metatarsal to exclude associated fracture. In special cases computed tomography (CT) or MRI scans may be indicated.
Table 8.7
191
Subta/ar joint
The inferior surface of the talus articulates with the superior surface of the calcaneus at three facets. The largest facet forms the posterior joint, which is separated from the others by the interosseous talocalcaneal ligament, which lies in the sinus tarsi. Pain may arise from damage to the sinus tarsi. The STJ produces triplanar motion. Because of the position of its axis - 42° from the transverse plane, 45° from the frontal plane and 16° from the sagittal plane (Root et al 1966) - little movement is produced in the sagittal plane but motion does occur in the frontal and transverse plane (L: 3 : 3).
Structures to palpate following an ankle injury
Tender structure
Possible diagnosis/injury
Distal fibular
Fracture
Lateral malleolus
Fracture
Lateral ligaments
Anterior talofibular ligament/calcaneofibular ligament (ATFUCFL) sprain due to forced inversion/plantarflexion. Complete tear of ATFL, CFL and posterior talofibular ligament (PTFL) follows an ankle fracture
Lateral aspect of talus
Fracture to lateral process of talus
Posterior aspect of talus
Fracture to posterior process of talus or os trigonum fracture
Peroneal tendon
Peroneal tendonitis due to excessive eversion, peroneal dislocation due to forced passive dorsiflexion and tearing of peroneal retinaculum or peroneal rupture
Base of fifth metatarsal
Avulsion fracture due to inversion injury
Anterior joint line
Articular damage (osteoarthritis)
Dome of talus
Osteochondral fracture associated with compressive component of inversion injury (landing from a jump)
Tibialis anterior
Tibialis anterior tendinitis due to overuse of ankle dorsiflexors secondary to restriction in joint range of motion
Posterior medial malleolus
Entrapment of posterior tibial nerve (tarsal tunnel syndrome) due to inversion injury or excessive pronation
Medial malleolus
Stress fracture
Medial (deltoid) ligament
Ligament sprain associated with fractured medial malleolus, talar dome
Tibialis posterior tendon
Tibialis posterior tendinitis (pain is exacerbated by passive eversion)
Sustentaculum tali
Flexor hallucis longus tendinitis (pain aggravated by resisted flexion of hallux or full dorsiflexion of hallux)
Sinus tarsi
Excessive subtalar joint pronation or ankle sprain
Anterior inferior talofibular ligament
The anterior inferior talofibular ligament (AITFL) is damaged in more severe ankle injuries. Occasionally associated with malleolar fractures
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SYSTEMS EXAMINATION
Alteration of the axis can favour motion in one direction at the expense of motion in another. The knee and foot are affected by the axial position of the STJ (Green & Carol 1984). Joint motion. To measure triplanar motion at this joint one would have to measure the motion produced in each plane; this is impossible to achieve clinically. The amount of frontal plane motion at the STJ can be measured, and this is used as an indicator of the ROM at the STJ. It is important that there is an adequate ROM and appropriate DaM at the STJ for normal pronation and supination of the foot. To assess frontal plane STJ motion the patient lies prone with the ankle and foot hanging over the edge of the couch. The distal third of the leg is bisected; this line is used as a reference point for measuring the ROM and DaM. The calcaneus is moved into its maximally inverted position and the posterior surface of the calcaneus is bisected (Fig. 8.22A). A tractograph is used to measure the angle between the bisection of the leg and the bisection of the posterior surface of the calcaneus. The calcaneus is placed in its maximum everted position and a reading is taken of the angle between the bisection of the leg and the bisection of the posterior surface of the calcaneus (Fig. 8.22B). Although this technique is helpful for clinical assessment, it is not considered accurate (Elveru et aI1988). Milgrom et al (1985) examined 272 male infantry recruits and an error in excess of 20% was identified. It is also recognised that for research purposes its reliability and validity are poor (Menz 1995). Some consider it to be so poor as to suggest that this method of examination no longer be used to determine the measurement of STJ movement (Buckley & Hunt 1997). A weightbearing assessment of STJ ROM would theoretically be a better indicator of the range utilised during walking. There is normally twice as much inversion as eversion (2: 1 ratio). Many patients appear to have a 3 : 1 ratio of inversion to eversion without any abnormal sequelae arising. Subtalar varus
Subtalar varus implies that the neutral position of the calcaneus is varus (inverted) in relation to
the leg bisection (non-weightbearing). Subtalar varus or rearfoot varus (discussed under static examination) can affect the function of the rearfoot during gait and may lead to excessive pronation of the foot and delay re-supination of the foot during gait. Abnormal pronation
Abnormal pronation, i.e. excessive STJ pronation during contact phase and/ or STJ pronation occurring when the STJ should be supinating during midstance and propulsion, is one of the most common disorders of the lower limb. A large degree of frontal plane motion in the foot (due to uncontrolled STJ pronation) is thought to predispose to forefoot pathology and ankle dysfunction, whreas a greater degree of transverse plane tibial rotation is thought to predispose to leg and knee pathology. The presence of four or more of the following indicates abnormal pronation: • more than 6° between the relaxed calcaneal stance position (RCSP) and the neutral calcaneal stance position (NCSP) • medial bulging of the talar head or 'midtarsal break' - quantified using the navicular drift technique (Menz 1998) • lowering of medial longitudinal arch quantified using the navicular drop technique (Mueller et a11993) • more than 4° eversion of the calcaneus • Helbing's sign (medial bowing of the tendo Achilles) • abduction of the forefoot at the MTJ (concavity of lateral border of foot) • apropulsive gait. Numerous conditions arising in the lower limb may lead to abnormal pronation; many of them have been highlighted in this chapter (the list is not exhaustive): • • • • •
internal or external torsion of the leg/ thigh tibial (genu) valgum/ varum coxa vara/ valga ankle equinus rearfoot varus
ORTHOPAEDIC ASSESSMENT
A
193
B
Figure 8.22 Assessing frontal plane motion at the ST J A. The distal third of the leg is bisected and a line is drawn at the bisection point. The posterior surface of the calcaneus is moved into its maximally everted position and the angle between the bisection of the leg and the bisection of the calcaneus is measured B. The calcaneus is moved into its maximally inverted position and the angle between the bisection of the leg and the bisection of the calcaneus is measured.
• inverted forefoot • everted forefoot. For treatment to be effective it is important that the cause and the extent of the abnormal pronation are correctly identified; otherwise, only symptomatic treatment on a trial and error basis can be provided. Examination of muscles affecting the ankle complex Plantarflexors. The posterior group of muscles plantarflex the foot at the ankle but may also restrict the amount of dorsiflexion at the ankle.
The patient should be asked to plantarflex the foot with and without resistance in order to test muscle strength. Rupture or partial rupture of the tendo Achilles should be ruled out. If the tendo Achilles is functioning normally the foot should plantarflex when the calf muscle is squeezed. Plantaris is a small muscle that is not present in everyone. Spontaneous rupture of plantaris may occur; it shows as a painful medial swelling over the posterior aspect of the calcaneus at its insertion near the tendo Achilles. Invertors. Tibialis posterior and anterior are the main invertors of the foot. These extrinsic muscles play an important role in re-supinating
194
SYSTEMS EXAMINATION
the foot during midstance and propulsion. To assess the strength of these muscles the patient should be asked to move his foot into supination against resistance. Dorsiflexors. The main dorsiflexors of the foot are the long extensors and tibialis anterior. To assess the strength of the anterior muscles the patient should be asked to dorsiflex the ankle with the foot in inversion against resistance. Weakness of the anterior group is often linked to neurological problems, e.g. poliomyelitis. The plantarflexors have a work capacity 4.5 times that of the dorsiflexors. If the dorsiflexors are weak the foot is held in a plantarflexed position as the plantarflexors have a mechanical advantage. Evertors. The evertors of the foot are the peronei. To assess the strength of the peronei the patient should be asked to evert the foot against resistance. The evertors are not as powerful as the invertors and in the case of neurological problems and/ or muscle imbalance the invertors have a mechanical advantage over the evertors and the foot is held in an inverted position (following a CVA). Tonic spasm of the peroneal muscles can occur; this is noted particularly with tarsal coalitions. A local anaesthetic can be administered in order to differentiate between a muscle spasm and a tarsal coalition.
Midtarsal joint The MTJ comprises two synovial joint complexes: talonavicular and calcaneocuboid. The MTJ is also known as the transtarsal or Chopart's joint, and is an articulation between the rearfoot and forefoot. The MTJ has two axes: longitudinal and oblique. The longitudinal axis provides frontal plane motion facilitated by the ball and socket joint of the talonavicular articulation. The oblique axis involves both calcaneocuboid and calcaneotalonavicular joints and primarily produces transverse and sagittal plane motion. Limitations of motion at the ankle joint are compensated at the oblique axis of the MTJ. The MTJ assists in reducing impact forces and helps to prepare the foot for propulsion. It can also accommodate walking on uneven terrain
without affecting the rearfoot. This means that the forefoot might invert while the heel remains vertical; the converse does not occur. Joint motion. To assess the motion at the MTJ the practitioner must stabilise the STJ and prevent any motion occurring at this joint by firmly holding the heel with one hand and holding the foot just distal to the midtarsal joint with the other. The MTJ should then be moved in the sagittal, transverse and frontal planes. There should be most motion in the sagittal and transverse planes and minimal motion in the frontal. The position of the axes will affect the amount of motion at the MTJ: e.g. a high (vertical) oblique axis will result in an increase in transverse plane motion but a reduction in sagittal plane motion.
Metatarsal examination The first and fifth metatarsals have independent axes of motion and produce triplanar motion. The second metatarsal is firmly anchored to the intermediate cuneiform and has least motion; the third has less motion than the fourth metatarsal. Whereas the first and fifth metatarsals provide triplanar motion, the central three only move in the sagittal plane. The ability of the first metatarsal to plantarflex is important in order that the medial side of the foot makes ground contact during gait and the first MTPJ can dorsiflex during propulsion. Patients commonly present with cutaneous changes associated with dysfunction of the metatarsals, especially the first and fifth. Sometimes one of the metatarsals may be held in a plantarflexed position. The position of the metatarsals can subsequently affect foot mechanics and gait. Joint motion. Clinical assessment of first and fifth metatarsal motion can only be satisfactorily undertaken in the sagittal plane. Unlike most joints, motion at the first and fifth rays is measured in millimetres, not degrees. To assess sagittal plane motion the patient can be in a supine or prone position. The feet must be allowed to hang free of the couch. The practitioner places one hand, with the thumb to the plantar surface, around the lateral side of the forefoot including the second metatarsal while maintaining the foot
ORTHOPAEDIC ASSESSMENT
195
in its neutral position. The other hand, again with the thumb to the plantar surface, is placed around the first metatarsal. The first metatarsal is moved into maximum dorsiflexion and plantarflexion. It is usual to find approximately 10 mm in each direction (Fig. 8.23A,B). Lack of plantarflexion of the first ray is known as metatarsus primus elevatus. The amount of
motion can be assessed using the thumb technique (Kelso et al 1982) (Fig. 8.23A,B). A Sagittal Raynger provides an alternative means of assessing first metatarsal motion (Fig. 8.23C,D) (Kilmartin et al 1991). Sagittal plane motion of the fifth metatarsal can be undertaken using the same approach. The validity of this technique is questionable, however, as it may not represent
A
B
C
D
Figure 8.23 Assessment of motion at the first ray A. Measurement of dorsiflexion of the first ray using the thumb test B. Measurement of plantarflexion of the first ray using the thumb test C. Dorsiflexion of the first ray measured with a Sagittal Raynger (reproduced by courtesy of Nova Instruments) D. Plantarflexion of the first ray measured with a Sagittal Raynger (reproduced by courtesy of Nova Instruments).
196
SYSTEMS EXAMINATION
the range the first or fifth metatarsal moves through during gait. Deformity. Deformity of the metatarsals is said to occur when the ROM or DOM of one or more metatarsals is asymmetrical or the metatarsal heads do not lie in the same plane. Table 8.8 refers to the various positions and terms associated with the deformities affecting the rays; these may be congenital or acquired. It is not unusual for a problem affecting the metatarsals to be unilateral. Metatarsal parabola. The metatarsal parabola should also be assessed and documented using the palpation technique (Spooner et al 1994), as abnormal metatarsal length is known to be associated with pathology. A short first metatarsal can be associated with the development of hallux valgus, whereas a long first metatarsal can cause hallux rigidus. Shortening of a lesser metatarsal (e.g. brachymetatarsia) can result in the development of intractable plantar keratosis, metatarsalgia or hammer toe deformity. Table 8.8 Abnormal positions ofthe metatarsals Position Normal position
Description
Thefirst and fifth metatarsals exhibit equal motion above and below the second/fourth metatarsal of 10-20 mm (5-10 mm in each direction) Metatarsus primus Reduces ability offirst metatarsal elevatus to bear weight and overloads central (dorsiflexed first metatarsal) metatarsals. Differential diagnosis forefoot varus. Shows limited plantarflexion and cannot be reduced below level ofsecond metatarsal Flexible plantarflexed Thefirst metatarsal may appear first metatarsal pronounced on the plantar surface ofthe foot with a cleft between the first and second metatarsal heads. Most ofthe movement is in the plantar direction. Loading the metatarsal head produces reduction ofthe position Rigid plantarflexed Thefirst metatarsal cannot be first metatarsal reduced at all from its plantarflexed position. Theforefoot tends to rotate in inversion during weightbearing; this affects rearfoot function
Metatarsophalangeal joints (MTPJs) The MTPJs are the joints between the metatarsals and the proximal phalanges; they produce motion in the sagittal plane. During the propulsive period of gait it is important that dorsiflexion occurs at these joints in order to facilitate toe-off. Joint examination. The ROM and DOM in the sagittal plane should be assessed for all MTPJs; they should have a free range of motion without pain or restriction (Fig. 8.24). The first MTPJ has the greatest range of motion: approximately 70-90° dorsiflexion and 20° plantarflexion (Bojson-Moller 1979). The ROM and DOM at the first MTPJ can be assessed with a tractograph or finger goniometer. The practitioner should appreciate that the declined angle of the first ray accounts for at least 15° of dorsiflexion at rest. A lack of dorsiflexion at the first MTPJ is known as hallux limitus, and a complete absence as hallux rigidus. The presence of either of these conditions, but particularly hallux rigidus, will affect toe-off and can lead to an apropulsive gait and overloading of one or more of the other metatarsal heads. Some authors also consider that this interferes with the angular momentum of the body (Miyazaki & Yamamoto 1993) and predisposes to the development of chronic postural complaints (Dananberg 1986, 1993). Hallux flexus is not so common; this is where the proximal phalanx adopts a plantarflexed position. Hallux extensus (trigger toe) is where the proximal phalanx is abnormally dorsiflexed; it is often associated with pes cavus. Restriction of movement at MTPJs could be due to osteophytes, loose bodies or articular damage, e.g. osteochondritis dissecans. The effects of Freiberg's disease may be to produce an enlargement of the metatarsal head and early osteoarthritic changes; this usually affects the second or third metatarsal. In some patients, particularly younger ones, the clinical appearance of the joint may appear normal and X-rays may reveal no abnormalities. It is essential in these cases that spasm of flexor hallucis brevis and/ or abductor hallucis is ruled out via the use of local anaesthetic blocks.
ORTHOPAEDIC ASSESSMENT
A
B
C
D
197
Figure 8.24 Assessment of motion at the MTPJs A. Dorsiflexion of the first MTPJ B. Plantarflexion of the first MTPJ C. Dorsiflexion of the second MTPJ D. Plantarflexion of the second MTPJ. In both cases (first and second MTPJ) dorsiflexion is greater due to the shape of the articular surfaces.
Interphalangeal joints (IPJs)
Alignment of the leg and foot
Toes have considerably less functional movement than fingers. The practitioner should note any restriction or fixed deformity affecting either the proximal (PIPJs) or distal (DIPJs) joints. Joint examination. The PIPJs can plantarflex (approximately 35°) but cannot dorsiflex (Fig. 8.25A). The DIPJs can dorsiflex to 30° and plantarflex up to 60° (Fig. 8.25B,C). The patient may be unable to actively move the toes to assess the function of the intrinsic muscles. However, plantarflexion can be assessed by placing the fingers under the apices of the toes and asking the patient to claw the toes around them.
While the patient is lying on the couch the following should be assessed: • • • • • • •
presence of genu varum/valgum malleolar torsion rearfoot to forefoot alignment arch height metatarsal formula toe position foot length.
Genu varumlvalgum. To assess the presence of lower limb varus or valgus the patient lies supine with the knees extended. The practitioner takes hold of the ankles and brings the legs together. If
198
SYSTEMS EXAMINATION
A
B
Figure 8.25 Assessment of motion at the IPJs A. Plantarflexion of the proximal IPJ B. Plantarflexion at the distal IPJ C. Dorsiflexion at the distal IPJ.
c
there is a difference of more than 5 cm between the knees genu varum is suspected; if it is impossible to bring the malleoli together a genu valgum is present (Beeson 1999). Obesity may prevent the knees and malleoli being brought together. Malleolar torsion. Torsion of the leg can affect the position of the foot, adducted (in-toe) and abducted (out-toe), as well as the position of the patellae. Assessing the amount of tibial torsion clinically is impossible, but it is suggested in the literature that assessing the relationship of the tibia and fibula malleoli to each other gives an indication of torsion in the leg (Hutter & Scott 1949, Lang & Volpe 1998). To measure malleolar torsion the patient lies in a supine position with the legs extended on the couch. The femoral condyles should lie in the frontal plane (i.e. par-
allel to the couch). The practitioner bends down until her eyes are level with the malleoli and observes the relationship of the malleoli to each other. The amount of malleolar torsion can be measured in three ways: • Estimate by using the thumb technique. Place the thumb of each hand anterior to the malleoli; the medial malleoli should be one thumb's thickness anterior to the lateral malleoli. • Traciograph. The protractor end of the tractograph should be held on the fibula side; one arm of the tractograph is placed parallel to the couch and the other arm is moved until it bisects the malleoli. • Gravity goniometer. The ends of the arms of the gravity goniometer are placed on the malleoli and the goniometer is held vertical (Fig. 8.26).
ORTHOPAEDIC ASSESSMENT
When the techniques were examined, the gravity goniometer fared best (Hayles & Lang 1987). Recent work suggests that there is good agreement between the gravity goniometer and CT scan measurements (Lang & Volpe 1998): 13-18° of malleolar torsion is considered normal. Tibial torsion is considered to be 5° more than malleolar torsion (Elftman 1945, Lang & Volpe 1998), therefore normal tibial torsion is 18-25°. Forefoot to rearfoot alignment. The plantar plane of the forefoot should lie parallel to the plantar plane of the rearfoot (Fig. 8.27B). The relationship of the forefoot to the rearfoot is
199
assessed by placing the foot in its neutral position; the patient may be either supine or prone but it is important that the foot hangs free of the couch. The neutral position of the foot is defined as the foot being neither pronated or supinated. To put the foot into the neutral position the practitioner should feel on the dorsum of the foot for the talar head. The foot should be moved into pronation and supination; while the foot is pronating the talar head can be felt protruding on the medial side of the talonavicular joint and while the foot is supinating it can be felt protruding on the lateral side of the talonavicular joint (Fig. 8.28). Neutral position is achieved when the talar head cannot be palpated on either side. As the foot is non-weightbearing it is also necessary to 'lock' the midtarsal joint in order to reproduce the position the foot would adopt if it were weightbearing. In order to lock the midtarsal joint the talar head should be held in its neutral position and a slight dorsiflexing force applied to the fourth and fifth met heads until the foot is at 90° to the leg. The neutral position of the foot therefore acts as a reference point from which joint motion and the position of parts of the foot can be assessed. While the foot is held in its neutral position a tractograph or a forefootmeasuring device can be used to measure any deviation of the forefoot to the rearfoot in the frontal plane; the forefoot may be inverted or everted to the rearfoot (Fig. 8.27C,A). Minor differences between the forefoot and rearfoot are usually insignificant and are often due to examiner error, but quite high angles of discrepancy can exist in excess of 15°. An inverted forefoot may be due to:
• True forefoot varus: bony abnormality,
Figure 8.26 goniometer.
Assessing malleolar torsion using a gravity
theoretically due to inadequate torsion of the head and neck of the talus during fetal development, but this is not well supported (Kidd 1997). The presence of a true forefoot varus is said to lead to a very flat foot with no longitudinal arch (Grumbine 1987). • Forefoot supinatus: acquired soft tissue deformity due to abnormal pronation of the rearfoot. The forefoot is held in an inverted position because of soft tissue contraction.
200
SYSTEMS EXAMINATION
Medial
A
Lateral
Medial
Forefoot valgus (everted 1-5)
Medial C
Lateral
Forefoot (1-5) parallel: rearfoot
B
Lateral
Forefoot varus (inverted 1-5)
Figure 8.27 Assessment of forefoot to rearfoot relationship A. Everted forefoot: the forefoot is everted to the rearfoot B. Ideal forefoot to rearfoot relationship: the forefoot is parallel to the rearfoot C. Inverted forefoot: the forefoot is inverted to the rearfoot.
This condition can be reduced with treatment. It can be difficult to differentiate between a forefoot supinatus and forefoot varus. Various techniques are suggested. One is to get the patient to stand; the foot is put into its neutral position. With both conditions
the medial side of the foot should not be in ground contact. Pressure is applied to the dorsum of the first ray: with a supinatus, there should be some give and the first ray should plantarflex; with forefoot varus, any pressure on the dorsum of the first ray
ORTHOPAEDIC ASSESSMENT
201
-------------------------_._-_.
A
B
Figure 8.28 Finding subtalar joint neutral A. Locating the talar head on the medial side B. Locating the talar head on the lateral side. It is easier to palpate the talar head on the lateral side than it is on the medial side.
should cause the foot to tilt inwards and the fifth ray to leave ground contact.
• Dorsiflexed first ray (metatarsus primus eleoaius): may be a fixed or flexible deformity.
• Plantarflexed fifth ray: as with the first ray this may be a fixed or flexible deformity dependent upon the cause, treatment may reduce the deformity. An everted forefoot may be due to:
• Forefoot valgus: bony abnormality, theoretically due to excessive torsion of the head and neck of the talus during fetal development which holds the forefoot in a fixed everted position that cannot be reduced with treatment. • Planiarjlexed first ray: a common cause of an everted forefoot position that may be due to a fixed or flexible deformity. • Dorsiflexed fifth ray: as with the first ray this may be a fixed or flexible deformity. The incidence of metatarsus primus elevatus and plantarflexed first ray is thought to be greater than that of forefoot varus and valgus. There may also be malalignment between the forefoot and the rearfoot in the sagittal and transverse planes. The forefoot may appear plantarflexed in relation to the rearfoot or vice versa. This may be a flexible or fixed deformity and may lead to a pes-cavus-type foot. The forefoot may appear adducted on the rearfoot; this may be due to a metatarsus adductus or metatarsus primus adductus; non-weightbearing the lateral border of the foot appears banana-shaped with a metatarsus adductus.
Arch height. The shape and height of the longitudinal arch should be observed and compared to its position when weightbearing. Creasing of the skin in the arch of the non-weightbearing foot usually indicates that the foot is mobile and excessively pronates on weightbearing. Metatarsal formula. The metatarsal formula refers to the apparent length of the metatarsals. The second metatarsal is usually the longest and the fifth the shortest. A typical metatarsal formula is 2 > 1 > 3 > 4 > 5 or 2 > 3 > 1 > 4 > 5. It is important that the first metatarsal is shorter than the second in order to allow normal function during propulsion. When the first MTPJ dorsiflexes the first ray plantarflexes on to the sesamoids; if the first metatarsal is as long as the second this cannot occur and as a result the first MTPJ is not able to dorsiflex, resulting in overloading of the other metatarsal heads, commonly the second. The practitioner should look at the shoe crease to observe the normal oblique angle afforded by the typical 2 > 1 > 3 > 4 > 5 formula. A rare but well-recognised formula is when the fourth metatarsal is congenitally short, known as brachymetatarsia (Tachdjian 1985). In this case the formula would be 2 > 1 > 3 > 5 > 4. The metatarsal formula is important for normal digital function. Abnormalities of the formula may affect forefoot pressure distribution, causing metatarsalgia. Short first metatarsals do not necessarily cause symptoms in the foot (Harris & Beath 1949); a correlation between long first metatarsals and the incidence of hallux abductus has been reported (Duke et al 1982). Minor changes in metatarsal length may not adversely affect forefoot function and weight distribution. Toe position. The position the toes adopt nonweightbearing should be noted and compared with the position they adopt weightbearing. Depending upon the effects of muscle pull and ground reaction, the extent of the deformity may reduce or increase on weightbearing. Foot length. The length and width of the foot should be measured non-weightbearing and compared with weightbearing measurements. Foot length and width should increase by a small amount when weightbearing; usually there is up to one or one and a half shoe size difference.
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SYSTEMS EXAMINATION
However, noticeable differences in foot length (two to three shoe sizes) indicates a mobile foot which excessively pronates during gait. No differences between the two is indicative of a rigid foot.
STATIC EXAMINATION (WEIGHTBEARING) To complete the assessment, the patient should be observed standing. Information from this part of the assessment should help to complete the picture of lower limb alignment, give an indication of whether compensation is occurring at the STJ and enable deformities of the forefoot to be observed. It may be helpful to ask the patient to walk on the spot for a few steps and then tell him to stop. The position the patient adopts on stopping can be accepted as the normal angle and base of gait. As with gait analysis, the patient should be observed from head to toe. The following should be noted: • • • • • • • • •
head shoulders spine pelvis angle and base of gait relaxed and neutral calcaneal stance position longitudinal arch toes foot width and length.
Points related to the position of the head, shoulders and pelvis are the same as those made for gait analysis. Any abnormality may be indicative of an LU, neurological or spinal problem. The shape of the lower limb and distribution of muscle bulk should be noted. There should be symmetry of muscle bulk, although there may be slight variation between the dominant and recessive side of the body. This is particularly true where one side, arm and/or leg engages in a greater level of activity than the other. Spine
The position of the vertebrae should be observed for the presence of kyphosis, lordosis or scoliosis.
A true scoliosis can be differentiated from a functional scoliosis by asking the patient to bend forward. If the spine is still deviated when the hips are flexed a true scoliosis exists; if vertebrae alignment improves it is likely to be a functional scoliosis. Angle and base of gait
A normal angle and base of gait is when the feet are slightly abducted (approximately 13° from the midline of the body) and the distance between the malleoli is approximately 5 cm (see Fig. 8.4A). Frontal plane deformity of the legs genu valgum or va rum - may be very noticeable when the patient stands and will affect the base of gait, i.e. the gap between the malleoli will be greater (genu valgum) or less (genu varum) (see Fig. 8.5). The angle of gait will be affected by torsional problems affecting the leg. Excessive internal torsion will lead to an adducted base of gait and squinting patellae, whereas excessive external rotation will lead to an abducted base of gait (greater than 13°) (Fig. 8.4B-D). Torsional problems may be due to bony or soft tissue problems; the true cause should be identified from the nonweightbearing assessment. Relaxed (RCSP) and neutral (NCSP) calcaneal stance position
The relaxed calcaneal position is an indicator of STJ motion when weightbearing. This position can be used to assess whether compensation for any proximal (e.g. tibial varum) or distal (e.g. forefoot varus) deformities has taken place at the STJ. The RCSP is measured by bisecting the posterior surface of the calcaneus; the angle this line makes with the ground is measured (Fig. 8.29A). The amount of calcaneal eversion or inversion (frontal plane) can be measured. Values greater than 4° eversion indicate the presence of abnormal pronation: • 0-4°: normal limits • 4-7°: moderate pronation requiring treatment if symptomatic or a cause for concern • 8° and above: marked pronation.
ORTHOPAEDIC ASSESSMENT
The causes of an abnormal everted RCSP are numerous, e.g. compensated forefoot varus, compensated ankle equinus, tibial valgum and varum, internal and external torsion of the leg. If the calcaneus does not have an everted position during RCSP it does not mean that abnormal pronation is not occurring. Compensation for a rearfoot varus involves excessive STJ pronation in order to bring the medial tubercle of the heel into ground contact and provide shock absorption during the contact phase of gait. A 10° rearfoot varus will require 10° of pronation in order to bring the heel into a verti-
A
203
cal position. Although excessive pronation has occurred, the RCSP will appear vertical and not everted. An inverted RCSP may be due to a neurological problem, an uncompensated varus deformity affecting the rear- or forefoot, subtalar joint damage, tonic spasm of the invertors of the foot or the presence of a plantarflexed first ray. The NCSP is measured by placing the foot into its neutral position while in ground contact and bisecting the calcaneus (Fig. 8.29C). The angle between the bisection of the posterior surface of the calcaneus and the ground should be mea-
B
Figure 8.29 Assessment of RCSP and NCSP A. Feet in relaxed calcaneal stance position (RCSP) B. Bisection of the posterior surface of the calcaneus and the distal third of the leg C. Foot held in the neutral position in order to assess neutral calcaneal stance position (NCSP).
C
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SYSTEMS EXAMINATION
sured; usually the calcaneus is in a slight inverted position. This is known as rearfoot varus and may be due to the presence of a subtalar varus (see non-weightbearing assessment of the STJ) and/ or tibial varum. The presence of a tibial va rum can be assessed during assessment of the NCSP. While the foot is in NCSP a bisection of the posterior surface of the leg should be compared to the ground. Ideally the bisection of the leg should be vertical to the ground (Fig. 8.29B). An angle of less than 90° when measured from the medial side of the bisection of the leg indicates a tibial valgum and an angle greater than 90° indicates a tibial varum. It was thought that the NCSP position was a composite of the STJ plus the tibial position. For example, a value of 7° rearfoot varus might be deemed to be made from 4° STJ varus and 3° tibial varum. A tibial valgum would conversely have a negative effect upon the presence of an STJ varus. Because of the inaccuracy and error in measuring these values, however, this concept is questionable. It is important to note the difference between the RCSP and NCSP in order to assess the compensation that occurs for proximal or distal problems (Fig. 8.29A,C). It is normal for there to be a difference of up to 6° between RCSP and NCSP; this is because most people have a slight subtalar varus and need to pronate to provide shock absorption. The limitations of comparing NCSP with RCSP is that it only provides information regarding frontal plane motion of the rearfoot. Some authors suggest that sagittal plane motion (Mueller et al1993, Payne & Dananberg 1997) or transverse plane motion (Nawoczenski et al 1995) may be a better indicator of foot pronation. Longitudinal arch
Arch shape is affected by the rearfoot and forefoot position, the declination angles of the metatarsals, the inclination angle of the calcaneus and the tone and activity of intrinsic and extrinsic muscles. In the past flat-footed people were rejected for the army as it was considered that their feet would not cope with the demands of
army life. However, there is rather more to foot function and mechanics than the height and shape of the longitudinal arch. The patient should be asked to stand on tiptoe and the position of the foot arch should be noted. With rigid flat feet the arch height does not increase when the patient stands on tip toe; with a flexible flat foot the arch height increases. Rigid flat feet may be due to bony coalitions (synostoses), contractures due to muscle imbalance or neurological paralysis with subsequent soft tissue contractures. The shape and size of the arch can be captured by taking a footprint; this can be used to monitor changes. Toes There are three main categories of pathomechanical causes of lesser hammer toe syndrome. Flexor stabilisation. A contraction (hammering) of all the lesser toes with an associated adductovarus deformity of the fifth and sometimes fourth toes (quadratus plantae losing its mechanical advantage). This can occur in an excessively pronated foot during late stance phase when flexor digitorum longus and/or flexor digitorum brevis have gained mechanical advantage over the interossei muscles. Pronation of the STJ allows unlocking of the midtarsal joint, resulting in forefoot hypermobility. The flexors fire earlier and longer than normal in an attempt to stabilise the forefoot. These muscles are ineffective at stabilising the forefoot but effective in overpowering the small interosseous muscles, thereby causing hammering or clawing of the toes. Flexor substitution. A straight contraction of all the lesser toes (with no adductovarus of the fourth and fifth toes). This can occur in a supinated foot during late stance phase when the flexors have gained mechanical advantage over the interossei muscles. This digital deformity occurs when the triceps surae muscle is weak and the deep posterior and lateral leg muscles try to substitute for the weak triceps. Flexor substitution is the least common of the three categories that create pathological hammer toe syndrome of the lesser toes.
ORTHOPAEDIC ASSESSMENT
Extensor substitution. Extensor substitution is a term that describes the excessive dorsiflexion of the toes during swing phase of gait and at heel strike. Extensor digitorum longus (EDL) gains mechanical advantage over the lumbricales. This can be due to a variety of factors. An anterior pes cavus, ankle equinus, pain, spasticity of the EDL muscle or weakness of the lumbricales. Without the stabilising effect of the lumbricales the MTPJs will be excessively dorsiflexed, resulting in severe dorsal contraction of the toes. This is commonly seen in pes cavus during non-weightbearing (Fig. 8.30) and can be emphasised by asking the patient to dorsiflex the foot. It is exaggerated during the swing phase of gait and at heel contact when extensor digitorum longus and brevis are normally active. This deformity often begins as a flexible deformity that may reduce completely during weightbearing but becomes more rigid as accommodative contractures develop. Hallux abductus and hallux abductovalgus are common complex deformities affecting the first MTPJ (Fig. 8.31). Slight abduction of the hallux is considered normal, up to 15°. Deviation of the hallux can be measured with a finger goniometer: the value should be recorded so that deterioration of the condition can be monitored. The fifth ray may frequently be abducted: tailor's bunion or digiti quinti varus may be associated with hallux abductus, giving a splayed
Figure 8.30 Flexed deformity of toes (28-year-old male) due to extensor substitution present on non-weightbearing and weightbearing.
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and therefore broad forefoot appearance. Changes in forefoot shape due to hallux abductus and digiti quinti varus can be monitored by taking photographs or ink prints of the foot on a regular (twice-yearly) basis. It is also useful to draw around the foot at regular intervals to gain a visual representation of foot shape and to monitor changes.
Figure 8.31 Hallux abductovalgus: abduction of the hallux with valgus rotation.
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Digital formulae should be noted. Usually the first toe is longest or the first and the second are of equal length - 1 > 2 > 3 > 4 > 5, 1 = 2 > 3 > 4 > 5. An excessively long toe, e.g. the fourth, may be impacted in footwear, resulting in toe deformity and secondary lesions. Deformities of the lesser digits (toes 2-5) can be described in various ways; unfortunately, there is no commonly agreed set of definitions. When assessing and recording the presence of digital deformities, the best approach is to describe the plane that the deformity is in - e.g. sagittal - and whether the deformity is fixed or mobile. A fixed deformity implies that there is no motion at the joint due to soft tissue changes and possible bony ankylosis; such deformities can only be corrected by surgery. Table 8.9 lists and defines the main toe deformities.
Table 8.9
Classification of toe deformities
Toe deformity
Description
Hallux abductus
Hallux abducted more than 15° from the midline of the body
Hallux abductovalgus
As above, but the hallux is also rotated so that the hallux nail faces towards the midline of the body
Hallux abductus interphalangeus
Distal hallucal phalanx abducted away from the midline of the body
Hallux varus
Hallux adducted towards the midline of the body
Hallux limitus
Reduced dorsiflexion at the first MTPJ
Hallux rigidus
Complete lack of dorsiflexion at the first MTPJ
Hallux flexus
Plantarflexion of the hallux at the first MTPJ
Hallux extensus
Dorsiflexion of the hallux at the first MTPJ
LIMB-LENGTH INEQUALITY
Hyperextended hallux
Distal phalanx of the hallux dorsiflexed
Once gait analysis, non-weightbearing and static weightbearing examinations have been completed it may be necessary to assess for limblength inequality. An LLI can have profound effects on the functioning of the musculoskeletal system, affecting the spine, sacroiliac and hip joints as well as the foot. A difference of greater than 1 cm can affect normal body alignment. In a sedentary person a small discrepancy may have a negligible effect upon posture, but if a person increases his level of physical activity, the effects of any imbalance become amplified. A leg-length discrepancy may be real, apparent or environmental. A real limb-length discrepancy is due to a difference in the length of the femurs or the tibiae and is common after a hip replacement. An apparent limb-length discrepancy may be due to a number of factors, e.g. osteoarthritis of the hip or a scoliosis. In addition, an environmental limb-length discrepancy may exist; this can be due to uneven footwear or camber of roads. It is important to identify the difference in length between the limbs and to differentiate between a real and apparent discrepancy prior to commencing treatment. It should be noted that a real and an apparent limb-length inequality may
Hammer toe
Dorsiflexion at the MTPJ, plantarflexion at the proximal IPJ and either normal position or dorsiflexion at the distal IPJ
Claw toe
Dorsiflexion at the MTPJ, plantarflexion at the proximal and distal IPJs
Retracted toe
Claw toe where the apex of the toe is not in ground contact
Mallet toe
Plantarflexion at the distal IPJ
Adductovarus fifth
Fifth toe rotated so that nail is facing away from the midline of the body and the toe is adducted (moved towards the midline of the body)
Dorsally displaced
One or more toes is in a dorsiflexed position in comparison to the other toes
coexist. The possible effects of treatment should be considered prior to commencing treatment (Case comment 8.6). The presence of a limb-length discrepancy can be observed during gait analysis: • shoulder tilt to one side • unequal arm swing • pelvic tilt
ORTHOPAEDIC ASSESSMENT
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Case comment 8.6 .:
It should be remembered that a patient who has had a discrepancy for years will have compensated by altering his/her body posture. If any raise under the heel is considered, this must only be for a proportion of the difference. Heel raises used alone may cause unwanted plantar flexion, especially when the deformity is greater than 2.5 em. The adaptation to footwear should affect the whole sole in this case.
• • • •
foot supinated on the short side foot pronated on the long side knee flexed on the long side ankle plantarflexed on the short side.
Limb length measurement is only performed if the patient's symptoms or dynamic function suggest that a discrepancy may be present. To assess for the presence of a real LLI the patient lies supine on a flat couch with the hips and knees extended. The practitioner places her hands around the heels and exerts a slight pull on the legs, at the same time bringing the legs together so that the knees and malleoli are touching. The knees and malleoli should be level. A difference indicates an inequality at the femur or tibia. To identify which bone is affected the knees should be flexed and the heels pushed flush against the buttocks (Skyline/Allis test) (Fig. 8.32). If the tibiae are of unequal length, the knees or tibial tubercles will be at different levels. If one femur is longer than the other, the knee of the longer femur will be positioned further forward than the other knee. This is a relatively crude method of assessment and does not quantify the extent of the difference. A flexible non-stretch tape measure with a metal end can be used to measure a real leg length ('direct measurement technique'). With the patient supine the distance between the anterior superior iliac spine (ASIS) and the medial malleolus is measured (Crawford Adams & Hamblen 1990). The metal end of the tape fits snugly in front of the ASIS, as shown in Figure 8.33A. The practitioner may use any part of the medial malleolus as a reference point, but it is important that the same point is used for repeat measurements. An error of up to 10%
Figure 8.32 Assessment of leg-length inequality.The knees are flexed so that the position of the knees and ankles can be compared.
should be allowed for because the tape measure may wrap around asymmetrical muscle bulk or, more commonly, the patient's pelvis may not be properly aligned. In cases of asymmetrical muscle bulk, measuring from the ASISs to the lateral malleoli is advocated. A tape measure can be used to compare the individual lengths of the femurs by measuring from the greater trochanter to the lateral knee joint line. The lengths of the tibiae can be compared by measuring from the medial knee joint line to the medial malleolus or the tibial tubercle to the middle of the anterior ankle. The 'indirect measurement technique' can also be used to assess a real leg length. The patient stands while blocks of wood of varying thicknesses are placed under the suspected shorter limb until the iliac crests are palpated to be level. Radiological measurement (Scannergram) is only used when surgical correction is planned, as it is expensive and, unless the results are going to
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be used for surgery, exposes the patient to needless radiation. Distinction between a real or apparent difference can be achieved by measuring each limb from a common reference point above the pelvis; the xiphisternum is usually used. The metal end of the tape is placed on the xiphisternum and the distance from the xiphisternum to each malleolus is measured with the patient (Fig. 8.33B). If values are the same, then the LLI is likely to be apparent. The cause usually lies at the hip or pelvis, where a fixed deformity makes the limbs appear unequal so that the body compensates by tilting laterally. An alternative method can be used with the patient weightbearing:
• The patient stands in the RCSP position (Fig. 8.29A). • The position of the ASISs is assessed to see if they are level. • The feet are then placed in the NCSP (Fig. 8.29C). • The position of the ASISs is assessed to see if they are level. • If the ASISs are not level in either the RCSP and NCSP, and the extent of the discrepancy remains the same in RCSP and NCSP, a true LLI should be suspected. If the ASISs are on the same level in the NCSP but differ for the RCSP, an apparent LLI should be suspected.
B Positioning for xiphisternum
Figure 8.33 Assessment of a true and apparent leg-length inequality A. Measurement from the anterior superior iliac spine (ASIS) to the medial malleolus B. Measurement from the xiphisternum to the medial malleolus.
ORTHOPAEDIC ASSESSMENT
SUMMARY Orthopaedic assessment of the lower limb is a complex process. Good observational skills, an ability to take a detailed history and an holistic approach to examination are paramount. It can be compared to doing a jigsaw - all the pieces have to be put together in order to produce the picture. Because the lower limb functions as one mechanical unit, it is important that the practitioner differentiates between primary and
209
any secondary problems. However, it is not always necessary to examine every component of the lower limb. The practitioner should weigh up the necessity for a head to toe examination against assessing isolated parts of the anatomy. This decision will be informed by data obtained from the patient's history, the presenting problem, a brief gait analysis and information from other parts of the assessment process.
REFERENCES Astrom M, Arvidson T 1995 Alignment and joint motion in the normal foot. Journal of Orthopedic Sports Physical Therapy 22(5): 216-222 Barnett C H, Napier J R 1952 The axis of rotation at the ankle joint in man. Its influence upon the form of the talus and the mobility of the fibula. Journal of Anatomy 86: 1-9 Beeson P 1999 Frontal plane configuration of the knee in children. The Foot 9(1): 18-26 Bojson-Moller F 1979 Anatomy of the forefoot - normal and pathological. Clinical Orthopaedic Related Research 142: 10-18 Brukner P, Khan K 1993 Clinical sports medicine. McGraw Hill, Sydney, p 438 Buckley R E, Hunt D V 1997 Reliability of clinical measurement of subtalar joint movement. Foot & Ankle International 18(4): 229-232 Crawford Adams J, Hamblen D L 1990 Outline of orthopaedics, 11th edn. Churchill Livingstone, Edinburgh, pp 280-283, 353 Dananberg H L 1986 Functional hallux limitus and its relationship to gait efficiency. Journal of the American Podiatric Medical Association 76(11): 648-652 Dananberg H L 1993 Gait style as an etiology to chronic postural pain. Part 1: functional hallux limitus. Journal of the American Podiatric Medical Association 83(8): 433--441 Duke H, Newman L M, Bruskoff B L, Daniels R 1982 Relative metatarsal length patterns in hallux abductovalgus. Journal of the American Podiatric Association 72: 1-5 Elftman H 1945 Torsion of the lower extremity. American Journal of Physical Anthropology 3: 255-265 Elftman H 1960 The transverse tarsal joint and its control. Clinical Orthopaedics 16 Elveru R A, Rothstein J M, Lamb R L 1988 Goniometric reliability in a clinical setting. Physical Therapy 68(5): 672-677 Gajdosik R L, Giuliani C A, Bohannon R W 1990 Passive compliance and length of the hamstring muscles of healthy men and women. Clinical Biomechanics 5(1): 23-29 Gajdosik R L, Rieck M A, Sullivan D K et al 1993 Comparison of four clinical tests for assessing hamstring muscle length. J Orthopaedic Sports Physical Therapy 18(5): 614-618 Green D R, Carol A 1984 Planal dominance. Journal of the American Podiatry Association 74: 98-103
Grumbine N A 1987 The varus components of the forefoot in flatfoot deformities. Journal of the American Podiatric Medical Association 77: 14-20 Harris R 1, Beath T 1949 The short first metatarsal: its incidence and clinical significance. Journal of Bone and Joint Surgery [Am] 31A(4): 553-565 Hayles M, Lang L 1987 Measuring tibial torsion: comparison of measurement techniques. ACTUK Journal Spring: 17-20 Hutter C G, Scott W 1949 Tibial torsion. Journal of Bone and Joint Surgery [Am] 31A: 511-518 Inman V T 1976 The joints of the ankle. Williams & Wilkins, Baltimore, p 65 Inman V T, Ralston H J, Todd F 1981 Human walking. Williams & Wilkins, Baltimore, pp 86-108 Kendall F P, Kendall-McCreary E, Geise-Provance P 1993 Muscles: testing and function, 4th edn. Williams & Wilkins, Baltimore, pp 68-77 Kelso S F, Ritchie D H, Cohen I R, Weed J H, Root M L 1982 Direction and range of motion of the first ray. Journal of the American Podiatry Association 72(12): 600-605 Kidd R 1997 Forefoot varus - real or false, fact or fantasy. Australian Journal of Podiatric Medicine 31(3): 81-86 Kilmartin T E, Wallace A, Hill T W 1991 First metatarsal position in juvenile hallux abductovalgus - a significant clinical measurement? Journal of British Podiatric Medicine 46: 43--45 Kulik S A, Clanton T 0 1996 Tarsal coalition. Foot & Ankle International 17(5): 286-296 Lang L M G, Volpe R G 1998 Measurement of tibial torsion. Journal of the American Podiatric Medical Association 88(4): 160-165 McRae R 1997 Clinical orthopedic examination, 4th edn. Churchill Livingstone, Edinburgh, pp 1-7 Menz H B 1995 Clinical hindfoot measurement: a critical review of the literature. The Foot 5(2): 57-64 Menz H B 1998 Alternative techniques for the clinical assessment of foot pronation. Journal of the American Podiatric Medical Association 88(3): 119-129 Milgrom C, Giladi M, Simkin A et al 1985 The normal range of subtalar inversion and eversion in young males as measured by three different techniques. Foot & Ankle International 5: 143-145 Miyazaki S, Yamamoto S 1993 Moment acting at the metatarsophalangeal joints during barefoot level walking. Gait Posture 1: 133-140
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Mueller M J, Host J V, Norton B J 1993 Navicular drop as a composite measure of excessive pronation. Journal of the American Podiatric Medical Association 83(4): 198-202 Nawoczenski D A, Cook T M, Saltzman C L 1995 The effect of foot orthotics on three-dimensional kinematics of the leg and rearfoot during running. Journal of Orthopaedic Sports Physical Therapy 6: 317-327 Payne C B, Dananberg H J 1997 Sagittal plane facilitation of the foot. Australian Journal of Podiatric Medicine 31(1): 7-11 Riegger-Krugh C, Keysor J J 1996 Skeletal malalignments of the lower quarter: correlated and compensatory motions and postures. Journal of Orthopaedic Sports Physical Therapy 23(2): 164-170 Rome K 1996a ankle joint dorsiflexion measurement studies - a review of the literature. Journal of the American Podiatric Medical Association 86(5): 205-211 Rome K 1996b A reliability study of the universal goniometer, fluid goniometer, and eletrogoniometer for the measurement of ankle dorsiflexion. Foot & Ankle International 17(1): 28-32 Root M L, Weed J H, Sgarlato T E, Bluth D R 1966 Axis of motion of the subtalar joint. An anatomical study.
Journal of the American Podiatry Association 56: 149-155 Spooner S K, Kilmartin T E, Merriman L M 1994 The palpation technique for determination of metatarsal formula: a study of validity. The Foot 4(4): 198-200 Sutherland D H et al1981 The pathomechanics of gait in Duchenne muscular dystrophy. Development of Medicine & Child Neurology 23(3): 3-22 Svenningsen S, Terjesen T, Auflem M, Berg V 1990 Hip rotation and in-toeing gait. A study of normal subjects from four years until adult age. Clinical Orthopaedics & Related Research 251: 177-182 Tachdjian M 01985 The child's foot. W B Saunders, Philadelphia Thackery C, Beeson P 1996 In-toeing gait in children: a review of the literature. The Foot 6(1): 1--4 Tiberio D, Burdett R G, Chadran A M 1989 Effect of subtalar joint position on the measurement of ankle dorsiflexion. Clinical Biomechanics 4: 189-191 Tomaro J 1995 Measurement of tibiofibular va rum in subjects with unilateral overuse syndromes. Journal of Orthopaedic Sports Physical Therapy 21(2): 86-89
FURTHER READING Altman M 11968 Sagittal plane angles of the talus and calcaneus in the developing foot. Journal of the American Podiatry Association 58: 463--470 Anderson J A D, Sweetman B J A 1975 Combined flexirule/hydrogoniometer for measurement of lumbar spine and its sagittal movement. Rheumatology & Rehabilitation 14: 173-179 Apley A G, Solomon L 1988 Concise system of orthopaedics and fractures. Butterworths, London Bailey D S, Perillo J T, Forman M 1984 Subtalar joint neutral. A study using tomography. Journal of the American Podiatry Association 74: 59-64 Bartlett M D, Wolf L S et al1985 Hip flexion contracture measurements. Archives of Physical and Medical Rehabilitation 66: 620-625 Bland J M, Altman D G 1986 Statistical methods for assessing agreement between two methods of clinical measurement. Lancet February: 307-310 Cochran G, Van B 1982 A primer of orthopaedic biomechanics. Churchill Livingstone, New York Coughlin M J, Mann R A 1999 Surgery of the foot and ankle, 7th edn. Mosby, St Louis D' Amico J C, Schuster R 01979 Motion of the first ray clarification through investigation. Journal of the American Podiatry Association 69: 17-23 Ebesui J M 1968 The first ray axis and first metatarsophalangeal joint. An anatomical and pathological study. Journal of the American Podiatry Association 58: 160-167 Fabry G, MacEwan G D, Shands A R 1973 Torsion of the femur. A follow up study in normal and abnormal conditions. Journal of Bone and Joint Surgery [Am] 55A: 1726-1738 Fairbank J C T, Pynsent P B, Van Poortvliet J, Phillips H 1984 Mechanical factors in the incidence of knee pain in adolescents and young adults. Journal of Bone and Joint Surgery [Br] 66B: 685-692
Green W B, Heckman J D (eds) 1993 The clinical measurement of joint motion. American Academy of Orthopaedic Surgeons, Illinois Green D R, Whitney A K Walters P 1979 Subtalar joint motion. A simplified view. Journal of the American Podiatry Association 69: 83-91 Hartley A 1995 Practical joint assessment: lower quadrant. Mosby, St Louis Helal B, Gibb P 1987 Freiberg's disease: a suggested pattern of management. Foot and Ankle 8(2): 94-102 Henry A P J, Waugh W 1975 The use of footprints in assessing the results of operations for hallux valgus - a comparison of Keller's operation and arthrodesis. Journal of Bone and Joint Surgery [Br] 57-B: 478--481 Hicks J H 1953 The joints. The mechanics of the foot. Journal of Anatomy 87 Holden M K et al1984 Clinical gait assessment in the neurologically impaired. Reliability and meaningfulness. Physical Therapy 64: 35--41 Kelso S F, Richie D H, Cohen I R et al 1982 The direction and range of the first ray. Journal of the American Podiatry Association 72: 600-605 Mann R, Inman V T 1964 Phasic activity of intrinsic muscles of the foot. Journal of Bone and Joint Surgery [Am] 46A: 469--481 McGlarnry E D 1992 Lesser ray deformities. In: McGlarnry E D, Banks A S, Downey M S (eds) Comprehensive textbook of foot surgery, 2nd edn. Vol. 1. Williams & Wikins, Baltimore Manter J T 1941 Movement of the subtalar and transverse tarsal joints. Anatomy Records 80: 397--410 Myerson M S, Shereff M J 1989 The pathological anatomy of claw and hammer toes. Journal of Bone and Joint Surgery [Am] 71A: 45--49 Norkin C C, White D J 1995 Measurement of joint motion: a guide to goniometry, 2nd edn. F A Davis, Philadelphia
ORTHOPAEDIC ASSESSMENT
Scott J H 1983 In: Harris N (ed) Leg length inequality, a postgraduate textbook of clinical orthopaedics. Blackwell, Oxford, pp 282-291 Sgarlato T E 1973 A compendium of podiatric biomechanics. California College of Podiatric Medicine Subotnick S I 1979 Cures for common running injuries. Anderson World, California Sussman R E, Piccora R 1985 The metatarsal sesamoid and
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first metatarsophalangeal joint. Journal of the American Podiatric Medical Association 75: 327-330 Welton E A 1992 The Harris and Beath footprint: interpretation and clinical value. Foot and Ankle 13: 462--468 Whittle M 1991 Gait analysis. An introduction. Butterworth Heinemann, Oxford Williams P L, Warwick R (eds) 1989 Gray's anatomy, 36th edn. Churchill Livingstone, Edinburgh
CHAPTER CONTENTS Introduction 213 Approach to the patient 213 Psychological aspects of skin disease 214 The purpose of assessment 214 How common is skin disease? 214
Assessment of the skin and its appendages 1. Bristow R. Turner
Skin structure and function 215 Epidermis 216 Dermo-epidermaljunction 217 Dermis 218 Skin appendages 218 )
History and examination of the skin 219 History taking 219 Clinical examination 220 Common tests and investigations 227 Recording of the assessment 228
INTRODUCTION
Hyperkeratoticdisorders 229 Assessment of corns and callus 229 Blistering disorders 231 Inflammatoryconditions of the skin 232 Eczema 232 Psoriasis 233 Vasculitis 234 Lichen planus 234 Granulomaannulars 235 Necrobiosis Iipoidica 235 Other inflammatory conditions 235 Allergies and drug reactions 235 infections of the skin 236 Viral 237 Bacterial 237 Fungal 238 Infestationsand insect bites 238 Disorders of subcutaneoustissue Systemic disorders and the skin Pigmented lesions 240 Skin tumours 242 Benign tumours 242 Malignanttumours 242 Summary 243
239 239
Dermatology is the study of the skin and its disorders. More than just an inert barrier, the integument is a highly active organ with an important role in physiology and homeostasis. There are over 5000 recognised skin disorders in existence but the largest percentage of skin disease is due to a handful of conditions, which may range from the trivial (i.e, minor bruising) to life threatening (i.e. malignant melanoma). Most skin diseases do not have a significant mortality, although they cause significant morbidity and have a high impact on the quality of life of patients (Harlow et al 1998). Typically, skin disorders affect individuals in a number of ways (the four Ds): • • • •
discomfort: i.e, itching and pain disability: i.e. foot ulceration, hand eczema disfigurement: i.e. scarring or rashes death: i.e. skin cancers.
APPROACH TO THE PATIENT The key to a good dermatological assessment is, firstly, a thorough history. This provides essential information and initiates an understanding of the patient as a person, the environment and an appreciation of the psychological aspects to the skin disease. The second stage is examination of the skin (with investigations when required). The skin is an easily accessible structure, but it is frequently difficult for non-dermatologists to examine and record their findings. Therefore a 213
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SYSTEMS EXAMINATION
basic orderly approach is required if a successful outcome is to be achieved.
Psychological aspects of skin disease The skin defines who we are and how we are perceived to be. It is on our appearance we are judged by others (Lawton 2000). One only has to see the amount of time and money invested in changing or enhancing our appearance to appreciate how important the skin and its appendages are. A common mistake of students when faced with a patient with widespread skin disease is to remain at a distance, avoiding any physical contact. Skin diseases are subconsciously often perceived as nasty, dirty or infectious. As a practitioner, preconceptions need to be overcome if the patient is to be reassured that they are in the care of an empathetic, understanding professional. It should be remembered that the problems of the skin patient may be more than skin deep, even with conditions that are perceived by the practitioner to be trivial. Many patients suffering the most common skin disorders such as psoriasis and eczema have a quality of life similar to patients with other chronic diseases such as rheumatoid arthritis, cancer and heart disease. Often, the visibility of skin lesions to others is not correlated to the sufferer's well-being (Fortune et al 1997) and many conditions may be aggravated by psychological stress, i.e. atopic dermatitis, psoriasis and lichen planus. It should also be borne in mind that often just acknowledgement and discussion of the wider problems with a patient, in a sensitive and empathetic manner, is an important aspect of the assessment (Case history 9.1).
THE PURPOSE OF ASSESSMENT The assessment procedure is at the heart of the diagnostic and treatment process. From a patient's perspective assessment is seen as the reaching of a diagnosis and arriving at a decision on the most suitable form of treatment, i.e. what it is and what can be done about it. Most patients' fears regarding skin disease revolve around
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Case history 9.1 Mrs F is a 50-year-old housewife with a 35-year history of widespread psoriasis. With no family history, she developed the disease in her teens. This made normal activities such as socialising and relationships impossible due to the widespread disease and its appearance. Every day, Mrs F has to spend 2 hours applying emollients and other medicaments that are often greasy and for most would be intolerable. Excessive washing of clothes and bed linen, as well as cleaning around the house, are everyday tasks due to the exfoliative nature of the disease. With time, Mrs F has undergone many forms of treatment for her condition, with limited success, but with the help and support of her family and health professionals she has developed her own coping strategy.
issues such as 'is it catching?' and 'will it get better?'. All the information gathered during the assessment will help to inform and reassure the patient accordingly. The difficulty is that many skin diseases, to the untrained eye, appear very similar. The second challenge is deciding whether the skin disease is part of an underlying systemic condition; therefore, the importance of the whole assessment process cannot be overstressed. Many underlying conditions may be reflected in the condition of the skin and nails. For example, clubbing of the nails is a feature often associated with smokers and those with lung disease. Recurrent ulceration and infection of the foot is a common diagnostic marker in diabetes mellitus. Recognising such features will improve the likelihood of a successful diagnosis and treatment plan.
How common is skin disease? Reliable data are difficult to obtain but skin disorders are thought to affect around a quarter of the population, with only a small percentage seeking professional help. Typically, 10-20% of a general practitioner's annual workload involves skin disorders (Office of Population Census and Surveys 1991), and podiatrists also spend a significant amount of time treating skin conditions (i.e. hyperkeratosis, nail disorders and wounds, etc.).
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Table 9.1
Of the most common disorders, most can affect the lower limb (Gawkrodger 1992): • • • • •
fungal and other skin infections dermatitis/eczema psoriasis warts tumours (benign and malignant).
Functions of the skin
Functions of the skin
Specific property
Barrier properties
Physical: thermal/mechanical/ radiation Chemical: irritants/allergens/ water loss Microbiological: infections/ infestations
Sense organ
Touch/vibration/pressure/ temperature Nociception
Other
Thermoregulation and assistance in maintaining blood pressure Vitamin D and cholesterol production
SKIN STRUCTURE AND FUNCTION The skin (or integument) is the largest organ system and covers around 1.8 m 2 • Much more than just an inert wrapping, the skin is a highly active organ that fulfils many functions (Table 9.1) which are determined by its structure. The skin comprises three layers: an epithelium (epidermis) and a connective tissue matrix (the dermis) firmly bound together at the dermoepidermal junction (Fig. 9.1); below the dermis lies the subcutaneous (fat) layer.
Across the whole body surface, there are considerable regional variations in the skin's structure, which in turn dictates its specific properties. These local variations may then influence the microclimate and therefore the pattern of organisms. Such variation may also
' t - - - - - - Hair
Skin surface
Epidermis ))------::::- Sweat duct Hair follicle -------'((11\--11Erector pili muscle - - - - - - - " ' \
Dermis
Hair bulb has a ----, rich vascular supply
-\
~
Sebaceous gland
~ Eccrine gland
Apocrine gland
Figure 9.1
215
Normal skin (not to scale) showing epidermis and dermis and the skin appendages, excluding nail.
216
SYSTEMS EXAMINATION
account for the typical distribution of skin disease.
Epidermis The epidermis (Plate 9) is an avascular structure, relying on the diffusion of materials across the dermo-epidermal junction for nutrients and waste disposal. It is principally composed of keratinocytes (corneocytes), which make up approximately 80% of the cells, as well as melanocytes, Merkel's discs and Langerhans' cells. Appendages of the epidermis include the nails, sweat glands and sebaceous glands (Fig. 9.1). The epidermis can range in thickness from around 0.4 to 1.5 mm, depending on the anatomicallocation; it is divided into four layers. Basal layer (stratum germinativum). For the most part, the basal layer consists of a single, undulating layer of cuboidal keratinocytes. The cells within this layer are firmly attached to the dermo-epidermal junction (OED by tonofilaments which arise from the cytoplasm of the cells linking into the hemidesmosomes anchored into the DEJ (Venning 2000). These mitotically active cells generate the cells of the more superficial layers of the epidermis. Scattered throughout this layer are specialist cells known as melanocytes. In sun-exposed areas (e.g. the face) they may have a ratio of 1 in 4, whereas on unexposed areas such as the plantar surface of the foot their numbers may decrease to 1 in 30. These cells are well developed in the epidermis of humans as we have a relatively hairless integument. Melanocytes are dendritic cells which produce a pigment melanin in specialist organelles known as melanosomes. These melanin granules then pass along the dendritic processes of the cell and are distributed evenly to adjacent keratinocytes. The melanin forms a protective cap over the cell nucleus, its function being to limit the amount of harmful ultraviolet radiation reaching the DNA within the nucleus. Recently, it has been proposed that melanin also has a role in mopping up free radicals, which arise as a result of inflammation within the skin (Norlund 1994). The amount of melanin produced across various races is roughly equal;
however, in darker skins the melanin granules are much more dense and less susceptible to degradation as they ascend through the epidermis. Merkel's cells are specialised nerve endings of unknown origin, possibly a modified keratinocyte (McKee 1996) found in the basal layer. Their function is thought to be the perception of light touch. They are typically only found in specific regions of the skin, being numerous on the volar (pulp) surfaces of the fingers and toes, in the nail beds and the dorsum of the foot. Prickle cell layer (stratum spinosum). The new cells generated by the active basal layer pass into the stratum spinosum. Here they become more polyhedral in shape. Internally, large numbers of keratin filaments (tonofilaments) surround the nucleus, whereas externally the cells have abundant spinous processes. These are desmosomes, bonding adjacent cells together, and are an important component of the epidermis, as they resist mechanical stress. In the upper part of this layer are the first lamellar granules. These secretory organelles contain many substances such as glycoproteins, phospholipids, sterols and lipases. Their significance is still being debated but it has been suggested that these granules are responsible for the barrier function found higher in the epidermis (Freinkel & Traczyck 1985). Langerhans' cells make up about 8% of the epidermis and are particularly found in the stratum spinosum. They are derived from bone marrow and are dendritic in structure, forming no apposition with the cells around them. Functionally, these cells are outposts of the immune system in the epidermis, recognising and presenting antigens to sensitised T lymphocytes and they have an important role in hypersensitivity and allergic reactions. Patients with specific skin diseases may have reduced numbers of Langerhans' cells. Granular layer (stratum granulosum). By the time the ascending cells have reached the granular layer they are much more flattened in appearance and are packed with keratohyalin granules. These granules are primarily composed of proteins and various types of keratins. As the cells move up towards the next layer of the epidermis the lamellar granules migrate to and fuse with
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
the cell membrane, expelling their contents into the intercellular space. The ejected lipid material is then organised into sheets at the junction with the stratum corneum. This forms a hydrophobic barrier (an almost watertight seal) along the junction of the two layers. In eczematous plaques, this process of extrusion is often reduced, leading to increased water loss through the epidermis and resultant fissuring (Cork 1997). Horny layer (stratum corneum). As the cell becomes cornified it loses a percentage of its water content and has a very flattened appearance with around 15-20 layers of keratinocytes. The remaining intracellular water accumulates, acting as a plasticiser with intracellular keratin, and causes the cell to swell. This improves the barrier seal to the epidermis and prevents fissuring of the skin under normal tensile forces (Cork 1997). Cells at this level begin a little understood pre-programmed cell death with most of the intracellular material undergoing breakdown, leaving just the keratin and protein matrix within these now cornified cells. Remnants of organelles and melanin pigment may be present within the stratum corneum. Normally, cells in this layer have lost their nucleus, but it may remain in incompletely keratinised cells (parakeratosis). The deeper cells in this layer are densely packed and so this area is often referred to as the stratum compactum (originally called the stratum lucidum). As cells ascend the stratum they continue to change. Modifications to the lipid membranes of the keratinocytes reduce adhesion, and so cells become less densely packed. There is also degradation of desmosomes, which further weakens cellular adhesions until the cells ascend to a level where desquamination is likely - the stratum dysjunctum. The skin as a barrier
The whole process of cell generation, maturation and degradation strives to create an effective barrier from water loss and from invading organisms, allergens or irritants. Many mechanisms are in place to help fulfil this function. However, the main threats to this barrier include trauma
217
(scratching, etc.), desiccation and hydration (Forslind 1994). Drying of the epidermis, central to many skin diseases, causes keratinocytes to shrivel and lose apposition, leading to fissuring, while excessive hydration strips the lipid barrier from the epidermis. Control of the keratinisation process
The epidermis can be considered an active organ, constantly generating keratinocytes in the basal layer which, in a period of 28-70 days, ascend through the superior layers, and undergo a cycle of maturation, keratinisation and desquamation. Regulation of this process is complex, but local factors within the epidermis, dermis and other tissues can modulate the rate of proliferation (i.e. inflammatory mediators in the dermis, tissue growth factors, fibroblasts, vitamin A derivatives, etc.). Disease processes may also disturb the normal equilibrium. Psoriasis often accelerates epidermal transit time to as little as 5 days, whereas skin carcinomas may trigger an uncontrolled proliferation of cell growth within the epidermis.
Derma-epidermal junction (DEJ) The point at which the dermis meets the epidermis is known as the dermo-epidermal junction. This is a basement membrane divided into a number of layers, crossed by a complex of filaments, keratins and proteins that form an anchoring surface between the dermis and epidermis. In areas of greater mechanical stress, to enhance adhesion the dermis makes regular finger-like folds into the overlying epidermis, known as dermal papillae. These are complemented by protrusions from the epidermis into the dermis, known as rete pegs or epidermal ridges. This undulation serves to increase the surface area of attachment and is a major feature of the plantar surface of the foot, where mechanical stresses can be high. Pathologically, the DEJ is the site of many pathologies and this can lead to loss of adhesion and the development of blistering diseases (i.e. epidermolysis bullosa, dermatitis herpetiformis).
218
SYSTEMS EXAMINATION
Dermis Below the dermo-epidermal junction lies the dermis. This consists essentially of dense fibroelastic connective tissues in a gel-like base (ground substance) which contains glycosaminoglycans. Collagen strands provide tensile strength, with elasticity afforded by interwoven elastic fibres that make this a pliable tissue. Accommodated within the dermis are the skin appendages, macrophages, fibroblasts and the neurovascular network. The thin, upper layer or papillary dermis contains most of the blood and lymphatic vessels, whereas the less vascular, deep reticular layer, is much more dense with collagen and elastic fibres. Cells of the immune system are present in the dermis, i.e. T lymphocytes and mast cells. Subcutaneous layer
The dermis is separated from the fascia by the subcutaneous (fat) layer. This is a layer of fat cells rich in nerves, blood vessels and lymphatics. Its main function is to provide thermal insulation and physical protection. To this end, it is well developed across the plantar surface, particularly across the metatarsal heads and heels where it may be up to 18 mm thick. Attached to the underlying fascia, plantar fat is divided into vertical chambers by dividing fibrous septae, which act as an effective shock absorption system. Blood supply and lymphatics
The main blood supply to the skin arises from a network (or plexus) of vessels located in the subcutaneous layer. At this lowest level, branches supply eccrine sweat glands located deep in the reticular dermis. Vessels ascend and fan out to form a second plexus in the mid-dermis. Arterioles from this level supply hair follicles and their associated structures. Other vessels ascend further to form a third plexus in the papillary dermis. From the papillary plexus, single capillaries loop upward into the dermal papillae. These tiny vessels loop and descend to drain into venules
within the papillary plexus and then descend further into the deeper dermis, eventually reconnecting with the subcutaneous blood vessels. Within the foot, the sole contains the most densely organised network of capillaries in the skin (Pasyk et al 1989), which correlates well to the thickness of the overlying epidermis. It has no thermoregulatory role. Lymph vessels are found throughout the dermis. Within the papillary dermis, highly distensible lymphatic end bulbs drain intercellular fluids and smaller particles. These empty into larger vessels, which descend to the lymphatics in the subcutaneous layer. Ryan (1995) suggests that their function is key to maintaining turgidity, which is vital to retain mechanical resilience in the skin, requiring a fine balance between supply and drainage, as dehydration and oedema can lead to a reduction in skin stiffness and deformation in the structure of collagen and elastic fibres.
Skin appendages Hair follicles and sebaceous glands. Hair follicles and their associated sebaceous glands are found on the lower limb, sparing the plantar surface. Compared with sebaceous glands in other areas of the skin (i.e. face, chest), these glands are relatively inactive. Sweat glands. Sweat glands exist in two forms. The larger apocrine glands are exclusively associated with the hair follicle in the groin and axillae, whereas the smaller eccrine gland is a simple coiled structure located in the reticular dermis with an opening directly onto the epidermis. Stimulated primarily by the sympathetic branch of the autonomic system, sweat glands are an important mechanism for thermoregulation, mainly above waist level (Ryan 1995). They are most numerous on the palms and soles. Under normal circumstances a small, steady flow of sweat is produced, which is thought to aid grip. This function is further enhanced on the palms and soles by the presence of dermatoglyphics. These skin creases, present at birth, are a result of the unique arrangement of collagen fibres in the dermis and are more prominent on
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
the weightbearing surfaces of the foot (pulp of the toes, heel and metatarsal area) and palmar area (fingerprints). Not only do they act like the tread on a tyre in conjunction with the small amounts of sweat, but within these areas, there is a dense and highly organised neural network in the underlying dermis (Montagna 1960) which provides a rich tactile perception necessary to protect the integrity of the foot.
HISTORY AND EXAMINATION OF THE SKIN Dermatological assessment consists of three parts: • history taking • clinical examination • common investigations and tests. It is often tempting when assessing the skin to leap straight to examination without resorting to the standard medical practice of history taking followed by examination. While this may give a correct diagnosis in experienced hands, often, to those new to dermatology, this will lead to an incorrect or incomplete conclusion. However, a brief initial examination may help to direct questioning for the history.
History taking Ideally, conduct the consultation in a private environment, with sufficient time to allow the patient to talk freely. You should expect to spend most of the consultation listening, only using questions to direct the history. It is important to ask patients what they think is the cause of the problem, as they are often correct. Starting the consultation by asking: 'How may I help you?' or 'Tell me about your problem' is beneficial. It lets patients know that they may talk and that there is willingness to listen, thus setting them at ease. However, certain facts are necessary to make a diagnosis and, if these are not offered, they should be asked for directly. Duration of the problem. The duration of a disease is essential to know. Whether the disease
219
is constant, deteriorating or fluctuating or whether there are periods of relapse and remission is useful. Acute or self-limiting conditions are usually inflammatory or infective (i.e. fungal infections), whereas chronic or progressive symptoms may be an indication of a more serious disease. Stressful events may give a remitting and relapsing pattern, particularly with psoriasis, eczema and lichen planus. Relieving or exacerbating factors. Does anything help the problem or make it worse? Many conditions are improved in sunlight, e.g. psoriasis, whereas others are made worse, e.g. lupus erythematosus. Relationships to physical agents. Does light, heat or cold playa part in the problem? Is it associated with any particular activity? Has injury played a part in the problem? Has there been exposure to chemical or plant material? Treatment. This is one of the most essential questions. Alongside their usual medications, often patients will have tried to treat the problem themselves and will have bought overthe-counter medications, preparations from health stores or perhaps borrowed a prescribed medication from a friend or family member. They may also have tried cosmetic preparations that they do not consider relevant. It is often helpful to ask them to bring in everything they put on the skin. In some instances the true appearance of the skin lesion may be altered or masked by previously applied medicaments. For example, a steroid cream applied to a fungal infection will dramatically increase the spread of the eruption. Past medical history. It is important to elicit any history of skin diseases, in particular psoriasis, eczema and skin cancer; all these conditions are pertinent to the lower leg and foot. Other salient conditions include information regarding a history of allergy, through either occupation or domestic exposure (e.g. epoxy resins from work or Elastoplast at home). Internal medical conditions may also be relevant, as many may manifest themselves in the skin. For example, dermatitis herpetiformis is a blistering disorder that is commonly associated with coeliac disease, a gluten intolerance affecting the gut.
220
SYSTEMS EXAMINATION
Occupation. Many occupations expose the skin to irritants and allergens. The patient may need to wear a particular garment or item of footwear as part of his job and that is causing the problem. It may be that other members of the workforce are similarly affected. Outdoor workers or workers who are exposed to wet or cold will also have problems particular to them: for instance, skin cancer is higher in those with outdoor occupations. Social history. It is useful to know who is at home with the patient as they may be able to help with the treatment. Enquiries about smoking should be made when considering circulatory problems, and alcohol consumption is relevant to a number of skin conditions, particularly psoriasis. Family history. A number of skin conditions run in families, e.g. palmoplantar keratoderma. Recessively inherited diseases may skip generations, so information is required about distant relations too.
Recognising the norm in the assessment of skin is essential. Normal variations are seen due to race and the normal ageing process. Any given population will include a significant range of skin colours. Lesions that appear red or brown on white skin, for example, often appear black or purple on pigmented skin and mild redness may be masked completely. In addition, some conditions have a distinct racial predisposition (e.g. melanoma in Caucasians). However, across all races, normal skin will not be different from surrounding skin and will feel smooth. As the skin ages, it appears more translucent with irregular pigmentation. Thinning of the skin occurs at all levels, including the subcutaneous layer, which may be evident on the plantar area of the foot. Natural turgidity and elasticity seen in younger individuals is lost. Pinching of the skin results in 'tenting', as the skin fails to return to its natural shape. As a result of decreased sweat and sebum production, the normal skin surface barrier is compromised and so is more prone to the effects of drying and irritation. A reduced immune response as the numbers of T and B lymphocytes, along with Langerhans'
cells, decrease potentially leave the skin more open to infection and malignant change. Also, any inflammation that occurs as a result of decreased immune surveillance tends to be dampened down; hence, signs of inflammation may seem less acute. With ageing, the nails may reduce their rate of growth and often become thicker and slightly yellow in colour.
Clinical examination Clinical examination of the skin uses a variety of senses. Sight is obviously the most important, but touch and smell are also valuable. Many trainees unused to dermatological assessment will shy away from touching the skin. This is clearly a natural reaction, but must be overcome in order to assess the area fully. Observation is an important stage in examination and it is important to follow a particular pattern: • general distribution (localised, widespread or regional) • individual lesion morphology • assessment of other structures • assessment of the nail • assessment of the sweat glands. General distribution
When a widespread eruption is suspected, it is important to look and ask about all of the skin. Patients may often be reluctant to discuss other areas or simply not connect them to the current condition. For example, scalp psoriasis can mimic dandruff. A patient concerned with scaly plaques on his knees may not connect the two, particularly if the dandruff has been present for some time. Many disorders have a typical pattern or predilection for specific sites, although it should be remembered that patterns could occasionally vary from the norm. Eczema has a common pattern - affecting the flexor surfaces of the arms and legs along with the face. Symmetry of the eruption should also be recorded as this usually denotes an endogenous condition. Table 9.2 highlights examples of the distribution patterns of various dermatoses.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
221
------_._---_._---------Table 9.2
Common patterns of skin disorders
Condition
Typical distribution pattern
Atopic eczema
Antecubital and popliteal fossa, face, neck, hands
Contact dermatitis
Hands, face, feet
Psoriasis
Extensor surfaces of knees and elbows, scalp, back, nails
Lichen planus
Flexor surfaces of wrist, ankles, oral cavity, genitalia
Erythema nodosum
Anterior surfaces of shins
Individual lesion morphology
Individual lesions should be assessed. A magnifying glass is useful along with good lighting. Initially it is important, if there is more than one lesion, to describe the arrangement (Fig. 9.2). This can include: • annular (ring-like), i.e. psoriasis, lichen planus, granuloma annulare • nummular (round, coin-like), i.e. nummular eczema • discoid (disc-like), i.e. eczema, psoriasis • reticulate (net-like), i.e. livedo reticularis • arcuate (curved), i.e. contact dermatitis • grouped, i.e. insect bites, dermatitis herpetiformis
o o
0
0
0
0
... Figure 9.2
0
Note that some disorders may have a number of configurations. Koebner's phenomenon is where skin lesions of a specific disease may appear at a site of trauma which was previously unaffected. The edge of the lesion should also be inspected. Is it discrete or ill-defined? For example, psoriasis and fungal infections have much more marked, well-defined edges than eczema. Surface contour should also be noted (Fig. 9.3). Colour. To interpret the skin colour of lesions, good lighting is essential, as temperature and dependency will modify appearances. Rashes or lesions that are pink, purple or red will be due to blood. If the blood is within vessels gentle pressure will whiten or blanch the lesions - this is erythema, and can be viewed best through a glass slide or tumbler. If it is not possible to blanch the lesion, this may be due to extravasation (loss of blood constituents into the skin) or pigmentation due to melanin. Touch. It is possible to determine surface changes in texture and whether the skin disease relates only to the surface of the skin or whether it relates to the structures beneath. Light touch is required to perceive superficial changes (i.e. texture of a surface lesion), whereas progressively
Annular Flat-topped
0
0
°A~ oW· o
• Koebner's phenomenon, i.e. warts, psoriasis (Plate 10), lichen planus, molluscum contagiosum.
Nummular
~
Pedunculated
Linear
~
Dome-shaped
Grouped
~
Umbilicated
Satellite
Verrucous
•
e
o
Spire (acuminate)
Arcuate
The various configurations of lesion patterns.
Figure 9.3
The different surface contours of lesions.
222
SYSTEMS EXAMINATION
deeper pressure will reflect changes to the lower structures in the dermis and subcutaneous layers. Oedema (collection of fluid within the tissue) feels flocculent under the fingers. Typical surface changes include a soft moist texture due to excessive sweating or a dry and roughened texture due to a lack of sweating, i.e. anhidrosis. Deeper lesions may be described as hard, nodular, mobile, soft, etc. Odour. Skin odour is a neglected aspect of skin examination but is useful. Colonisations of pseudomonas, staphylococcus, or diphtheroids have distinctive smells (microbiology may help to confirm this) as do odours associated with excessive sweating (bromhidrosis) and incontinence. When examining individual lesions, clear descriptions using well-recognised terms are essential. This allows good communication between health professionals. In dermatology, there are many descriptive terms: some obvious, others less so. Familiarity with this terminology will ensure good inter-professional communication. Skin lesions can be classified as to whether they are primary or secondary. Primary lesions arise due to the initial effects of a condition; secondary lesions evolve from or as a complication of primary lesions. The distinction between primary and secondary is not always clear; some lesions can be classed as primary or secondary (Tables 9.3 and 9.4). Some of the more common terms used in assessing the surface of the skin are described below. Scaly. Normally the skin sheds skin cells individually or in small clumps. This is imperceptible to the eye. If the skin is weathered or diseased, skin shedding becomes abnormal, the clumps of skin become larger and appear as flakes or scales. These scales may be small, as in the dryness (xerosis) of atopic eczema, or large, as in ichthyosis. Scratching the surface of skin is helpful as it accentuates scaling and may help with diagnosis. Psoriasis will demonstrate pinpoint bleeding when scratched and the scaling will become more pronounced (Auspitz sign). Crusting and exudation. When the skin is injured or infected, it bleeds, oozes serum or discharges pus. This is an exudate; it dries to form a crust, which is distinguished from scale by clini-
Table 9.3
List of primary skin lesions
Term
Description and example
Erythema
Redness, often due to inflammatory response
Macule
Flat, differently coloured, e.g. freckles, vitiligo
Papule
Palpable, solid bump in skin, e.g. lichen planus
Nodule
Palpable, deeper mass than a papule, e.g. ganglion, rheumatoid nodule
Plaque
Elevated, disc-shaped area of skin over 1 cm in diameter, e.g. psoriasis
Tumour
Large mass over 2 cm in diameter, e.g. lipoma
Cyst
Subdermal, fluid-filled fibrous swelling, loosely attached to deeper structures, e.g. dermal cyst
Weal
Large oedematous bump, e.g. insect bite
Vesicle
Tiny, pinprick-sized collection of fluid, e.g. mycosis, pompholyx
Bulla
Serous fluid/blood-filled intraepidermal or dermoepidermal sac, e.g. bullous pemphigoid
Pustule
Vesicle or bulla filled with pus, e.g. acne, pustular psoriasis
Burrow
Short, linear mark in skin visible with magnifying lens, e.g. scabies
Ecchymosis
Large extravasation of blood into the tissues, i.e. bruising
Petechia
Pinhead-sized macule caused by blood seeping into skin
Telangiectasiae
Permanently dilated small cutaneous blood vessels
cal appearance and history. While avoiding hurting the patient, try to remove the crust as this often obscures the true pathology. Crusting is a common feature in eczema. Hyperkeratosis and lichenification. If keratin is abnormal, it forms thickened areas as shedding fails. These can be localised, appearing as horns on the skin and usually reflect a viral or neoplastic process. Sometimes the surface can be papillomatous (warty). The areas of thickening can be more diffuse, e.g. chronic plantar eczema or corns. Such areas are less flexible and will often crack, forming deep fissures. Lichenification is a reaction of the skin to chronic rubbing or scratch-
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
223
--------_._----------------------_._Table 9.4
List of secondary skin lesions
Term
Description and example
Scale
Flake of skin, e.g. mycosis, psoriasis
Crust
Scab, dried serous exudates, e.g. acute eczema
Excoriation
Scratch marks, e.g. pruritus
Fissure
Crack in dry or moist skin
Necrosis
Non-viable tissue
Ulcer
Loss of epidermis; may extend through the dermis to deeper tissue, e.q. venous ulcer
Scar
Fibrous tissue production post-healing
Keloid
Excessive production of fibrous tissue post-healing
Striae
Lines in skin that do not have normal skin tone, e.g. striae tensae in pregnancy, Cushing's disease
Purpura
Purplish lesions which do not blanche under pressure, e.g. vitamin C deficiency
Urticaria
'Nettle rash', e.g. drug eruption, allergy, heat
Lichenification
Patchy 'toughening' of skin, e.g. chronic eczema
Haematoma
Blood-filled blister
Sinus
Channel that allows the escape of pus or fluid from tissues
ing and involves the whole epidermis. The affected area of skin thickens and the skin markings become more pronounced. It is a common feature of atopic eczema and usually occurs on the flexures. Excoriations, erosions and ulcers. Excoriation means scratch and is usually a feature of itching or, less commonly, pain. It may represent underlying skin pathology such as scabies or eczema or indicate disease elsewhere, e.g. renal or hepatic failure. Erosions are partial-thickness breaks in the surface of the skin caused by physical injury including excoriation or where blisters have broken. An ulcer is an area of full-thickness skin loss, usually covered by exudate or crust. Atrophic. The surface of the skin is depressed and blood vessels are visible beneath. It may be due to atrophy of the epidermis or dermis. The skin is often pale and wrinkled.
Macules and patches. These are localised impalpable areas of colour change: macules are less than 1em in diameter and patches are greater than 1 cm. Papules, plaques and nodules. A papule is any lesion less than 1 em in diameter that rises above the surface of the skin. A nodule is larger than 1 em in diameter, but otherwise similar to a papule, and usually due to pathology within the dermis. A plaque is a raised lesion that is wider than it is thick and often represents epidermal pathology. Vesicles, bullae, pustules and abscesses. Small blisters less than 1 cm are called vesicles. Blisters larger than 1em are called bullae. Pus-filled vesicles or bullae are pustules, large pustules are abscesses. Weal. These are transient papular or plaquelike swellings of the skin due to dermal oedema and frequently seen in urticaria. Scars. These can be macules, papules or plaques and are a feature of repair following dermal injury. A glossary of terms can be found in Tables 9.3 and 9.4.
Assessment of other structures
When examining the skin, other structures such as the nails, hair and mucous membranes may add clues to the diagnosis. For example, lichen planus commonly causes lesions in the mouth; this may be an important finding in differentially diagnosing it from other conditions such as eczema and psoriasis. Palpation of the lymph nodes is important in patients with suspected skin malignancy. Assessment of the nail
Inspection of the nails should be included as part of the main dermatological assessment. The nail has evolved as a rigid structure to improve dexterity but in the foot the nail is purely a protective plate overlying the deeper structures and acting as a counter pressure to the volar tissues (Baran et al 1996). The nail unit (Fig. 9.4) is well provided with a rich neurovascular supply and, as a result, is sensitive to internal changes, often man-
224
SYSTEMS EXAMINATION
Dorsal nail matrix
Dorsal nail piate ---t:-:::-::::=::-:::-=-=-:::-:::-::-:=Intermediate nail plate Ventral nail plate --~"""", Hyponychium - - - j
Dermo-epidermal junction
Vertical collagen fibres in dermis PHALANX Limit of lunule
Intermediate nail matrix
Nail bed matrix Figure 9.4
Structure and anatomy of the nail.
ifesting these subtle changes in the nail structure. External factors too, such as trauma, can modify nail shape. Therefore, a proper footwear assessment should be undertaken, to complete the clinical picture, when looking for reasons for changes in nail shape, colour, etc. A glossary of the main terms used to describe nail changes can be found in Table 9.5. Key aspects of examination should include assessment of the following factors. Pattern of affected nails. It is important to always assess finger nails as well as toe nails and note any findings. Often finger nails may show changes more readily (i.e. clubbing). Where only one or two nails are affected, or one foot, local causes should be suspected, whereas nail changes in all digits in both feet and hands suggests a systemic or internal cause. On the foot, the length or the position of the toes may give clues to local nail abnormalities. Typically, the longest toe may show nail changes as a result of interaction with footwear. Rate of nail growth. There is great variation between individuals in the rate of nail growth. The average rate for a finger nail is 0.1 mm/ day (or 3 mm/month), whereas toe nails grow at a half to a third of this rate (Zaias 1980). Consequently, a normal finger nail will grow completely in about 6 months, whereas a toe nail will take 12-18 months. Such information is
Table 9.5
Glossary of nail conditions
Condition
Definition
Onychauxis
Thickening of the nail plate, usually due to trauma
Onychogryphosis
Thickened nail with a distortion in the direction of growth
Onycholysis
Separation of the nail from the nail bed, distal to proximal
Onychomadesis
Separation of the nail from the nail bed, proximal to distal
Onychocryptosis
Ingrowing toe nail
Involution
An inward curvature of the lateral or medial edges of the nail plate, towards the nail bed
Splinter haemorrhage
Longitudinal, plum-coloured linear haemorrhages (around 2 mm in length) under the nail plate
Paronychia
Inflammation of the tissues surrounding the nails
Onychomycosis
Fungal infection of the nail plate
Chromonychia
Abnormal coloration of the nail tissue
Koilonychia
Transverse and longitudinal concave nail dystrophy which gives a spoon-shaped appearance
Clubbing
Increased longitudinal curvature of the nail plate with enlargement of the pulp of the digit
Beau's lines
Transverse ridging of the nail plate seen as the result of a temporary cessation of nail growth
ASSESSMENT OFTHE SKIN AND ITS APPENDAGES 225 useful to determine the approximate time of events: e.g. the time of trauma to a nail, the likely clearance time of a haematoma. Most systemic disorders lead to a decline in the rate of nail growth but a few may have the opposite effect (psoriasis, hyperthyroidism, nail trauma and drugs). Shape of the nail plate. The breadth of the nail matrix and length of the nail bed normally dictate the shape of the nail plate (finger nails being rectangular and toe nails, quadrangular). The contour of the underlying phalanx, and toe position, may modify this. The most commonly occurring nail shape alteration in the toe nail is transverse over-curvature or involution (pincer nail). This is typically seen in the nail plate of the hallux and is often accompanied by pain when direct pressure is applied to the nail. If there is an underlying subungual exostosis (Plate 11), lifting of the distal nail plate occurs, often accompanied by pain. Frequently seen in young adults, a lateral X-ray will differentiate between this and other causes of painful nails (e.g. onychocryptosis). Internal causes of nail shape alterations include koilonychia (spooning) and clubbing: their causes are listed in Table 9.6. Colour of the nail plate and bed. Changes in nail colour (chromonychia) may arise as a result of external or internal factors. Finger nails, in particular, are vulnerable to occupational causes such as chemical agents. Colour change can occur on the surface of the nail, within the nail plate itself or below in the underlying nail bed or lunula. The use of a powerful pen torch or laser pointer shone in the pulp of the digit, through the nail plate, can help to isolate the source. Table 9.7 lists the more common causes of chromonychiao Splinter haemorrhages are plum-coloured streaks of about 3-4 mm seen running longitudinally under the nail plate. These are the result of extravasation of blood between the nail bed and plate. Typically they are caused by trauma, though, if the majority of nails are affected, disorders such as rheumatoid disease, vasculitis or skin diseases (psoriasis and eczema) should be suspected.
Table 9.6
Causes of nail spooning and clubbing
Koilonychia (spooning) Idiopathic
Clubbing Idiopathic
Hereditary
Hereditary
Iron deficiency anaemias
Lung disease: bronchiectasis lung cancers abscess lung infections fibrotic lung disease emphysema asthma in childhood
Insulin-dependent diabetes Physiologically thin nails (i.e. children) Psoriasis Alopecia Lichen planus Raynaud's disease Scleroderma/systemic sclerosis Renal transplant Thyroid disease Acromegaly Occupational (immersion in oils, acid and alkali)
Cardiovascular disease: congestive heart failure subacute bacterial endocarditis myxoid tumours congenital heart disease Alimentary disease: ulcerative colitis Crohn's disease gut cancers Endocrine: active hepatitis auto-immune thyroiditis acromegaly Other: polycythaemia cirrhosis malnutrition
Surface texture. The surface of the nail is normally smooth but changes may occur. Subtle longitudinal lines may arise with age or as a result of minor trauma, although specific diseases may accentuate their appearance (rheumatoid arthritis, peripheral vascular disease and lichen planus). Solitary lines or ridges may signify a tumour within the matrix or be the result of a previous paronychial infection. Transverse lines are common in the hallux as a result of repeated minor trauma from footwear. When transverse lines affect the majority of nails simultaneously they are known as Beau's lines and may represent a sudden period of illness. By noting their distance from the cuticle, a rough calculation can be made as to the time of the illness. Pits are small erosions in the nail found on the surface of
226
SYSTEMS EXAMINATION
Table 9.7
Causes of nail discoloration (chromonychia)
Discoloration
Cause
Nail bed
Idiopathic, subungual wart Anaemia, cirrhosis, renal disease Pseudomonas infection, blistering diseases Subungual corn, wart or exostosis, jaundice Haematoma
Brown White Green Yellow Brown/black Lunula
Congestive heart failure, alopecia Haematoma, melanoma, melanonychia
Red Brown/black Nail plate
Onychomycosis, trauma, onycholysis Nicotine or urine staining, yellow nail syndrome, jaundice Mycotic infection, onychauxis, onychogryphosis, shoes dyes, melanoma
White Yellow Brown
the nail plate. When only a few nails are affected it is considered a variant of normal but multiple nail involvement is seen in a number of skin diseases such as psoriasis, lichen planus, eczema and alopecia. Loosening or shedding of the nails. Onycholysis is the detachment of the nail from the bed in a distal to proximal fashion, whereas onychomadesis occurs in the opposite direction. The aetiology for both conditions is similar (Table 9.8) but it is most frequent as the result of trauma, particularly overzealous nail care or fungal infection. The loosened area is usually white, although in some disorders the area may adopt a different colour. Table 9.8
Causes of nail shedding
Level of separation
Cause
Onycholysis
Trauma (nail surgery, nail picking) Peripheral vascular disease Psoriasis Rheumatoid arthritis Subungual tumours Eczema
Onychomadesis
Nail matrix infection or inflammation Subungual blistering Drugs
Onychomadesis is the less common of the two conditions. Proximal detachment occurs most frequently due to acute bacterial infection of the proximal nail fold or an acute skin eruption affecting the nail bed such as a blister or psoriatic plaque. Nail thickness. Thickening of the nail (onychauxis) is probably the most commonly observed toe nail condition. Long-term trauma to the nail plate can lead to hypertrophy of the nail, often with a brown discoloration. Typically, the condition affects the hallux or longest toe as a result of footwear interaction. Other conditions such as fungal infections, psoriasis and lichen planus may also lead to onychauxis. Onychogryphosis is a more severe thickening of the nail plate often with gross deformity and a deviation in the direction of nail growth. Pachyonychia congenita is a rare inherited disorder hallmarked by congenital thickening of the nail plate. Periungual changes. The periungual tissues seal the nail unit from damage but may show disease themselves. These tissues may be breached by inappropriate nail care or prolonged immersion, e.g. water, chemicals, etc., leading to infection or chemical irritation and thus paronychia. Acute paronychia is more commonly associated with infection, whereas the chronic variety is often confined to the hands, most often as a result of irritant reactions. Other periungual conditions include tumours: • Periungual warts - usually asymptomatic, easily diagnosed by their appearance. • Corns/callus - found within the nail sulcimay lead to pain on compression of the nail plate. Nail edges may be thickened or involuted. • Subungual exostosis - diagnosed by X-ray, may lead to lifting of the nail plate. • Fibromas - associated with tuberous sclerosis. • Malignant tumours - basal cell carcinoma, squamous cell carcinoma, subungual melanoma. • Glomus tumours - causes of extreme pain when exposed to slight trauma or changes in temperature, often visible by digital illumination. Rarely are they found in the toe.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Assessment of the sweat glands
Table 9.9
Eccrine sweat glands are particularly numerous across the palms and soles. Normally these sweat glands play no part in thermoregulation; their activity is increased during mental stress and anxiety. When assessing sweat gland function, excessive local sweating usually has a local cause, whereas generalised sweating may have a more systemic cause. The two most common disorders are:
Cause
Causes of sweating disorders
Anhidrosis Ageing: Damage to neurological pathways
Displacement of sweat ducts Dermatological lesions
• anhidrosis - a lack of sweating • hyperhidrosis - excessive sweat production. The causes of each of these conditions are summarised in Table 9.9. When assessing sweating disorders it is pertinent to look for associated symptoms, e.g. concurrent tachycardia in the absence of a fever may suggest thyrotoxicosis. An elevated temperature and lymphadenopathy may indicate infection. Hyperhidrosis. When symmetrical, this condition is most commonly associated with young active individuals: it is usually physiological rather than pathological, with resolution occurring in the third decade. Sweat production may increase to such an extent that the skin becomes overhydrated and macerated, particularly if footwear /hosiery is occlusive. Moist fissures may develop, mostly interdigitally, along with blistering of the soles. At this stage secondary bacterial or fungal infection can occur, generating an unpleasant odour and even a brown discoloration to the skin (bromhidrosis). Anhidrosis. Anhidrosis should be considered as a condition normally associated with ageing. In severe cases cracking and fissuring of the epidermis may occur, particularly around the heel. Deep fissuring may develop into the dermis with subsequent recurrent bleeding, a common feature with eczema.
Common tests and investigations • fungal assessment and other microbiology • histological assessment • patch testing.
227
Hyperhidrosis Physiological
Examples
Sweat production decreases with age Autonomic neuropathy Diabetes mellitus Leprosy CNS disorders Eczematous or psoriatic plaques Lichen planus Miliaria Lack or loss of sweat glands Damage Iscarring to areas of skin Congenital lack of sweat glands (ectodermal dysplasia) Normal in young adults Exercise Over-clothing or occlusive footwear Emotions or stress
Endocrine disorders
Hypoglycaemia Hyperthyroidism Acromegaly
Dermatological
Associated with palmoplantar keratoderma
Other
Drugs CNS disorders Cardiovascular disorders Respiratory failure Tumours
Fungal assessment and other microbiology
Fungal diseases enjoy the conditions of the foot and are a major contributor to both primary and secondary disease. It is essential to have a high index of suspicion in any disease of the foot, particularly those that are scaly or blistering. Wood's light and mycology are the two main methods of assessment in fungal disease. Wood's light. This is filtered ultraviolet light, excluding the visible spectrum. Fungus within the skin will fluoresce under Wood's light, thus revealing subclinical infection and helping with diagnosis, but the fluorescence is not bright, so good blackout facilities are essential.
228
SYSTEMS EXAMINATION
Microsporum species are the main types detectable by this method (fluorescing green), but other pathogens also fluoresce, notably erythrasma (caused by Propionibacterium minutissimum and fluorescing coral pink). Mycology. Fungal disease usually affects the most superficial aspects of the skin and so is easy to remove for assessment by scraping. A 15 blade is ideal to do this. After carefully scraping across the skin, the scale is collected either on a glass slide or onto a small piece of black paper. Where possible, if blisters are present, the whole roof should be removed. The undersurface of the blister is then scraped to remove the fungal debris onto a glass slide; the remaining skin is sent for culture. With nails, a clipping from the most proximal part of the affected nail is useful, along with any subungual debris. Potassium hydroxide (20%) when applied to the sample on the glass slide will render the sample transparent after 20 minutes or so, thus revealing the underlying fungal elements. The scrapings are then sent for expert examination and culture, after placing the sample onto folded black card. More than sufficient scrapings should be sent whenever possible to ensure a representative result. Bacterial and viral culture. Infection with bacteria should be considered wherever inflammation or pus is present. A swab is taken by rubbing it onto the affected area; if the lesion is a blister or pustule, the surface should be broken first with a sterile needle. The swab is moistened with some of the culture medium when assessing dry lesions. Biopsy tissue can also be cultured. It is important that this does not dry out, so it is sent either in sterile water or within the culture medium of a swab. Viral specimens need a viral transport medium. Contact the microbiology lab before taking the sample, as some labs will take the specimens themselves. Histological assessment
Clinical examination of the skin only allows a view of the surface morphology, whereas histopathology is an easy and valuable adjunct whenever diagnosis is in doubt. Under local anaesthesia, small suspicious lesions are usually
excised in their entirety, whereas larger lesions need to have a carefully placed sample taken that includes both normal and abnormal skin. It is good practice to refer suspicious pigmented lesions for expert assessment rather than biopsy. The three main biopsy techniques are punch, shave and ellipse. Punch biopsies are a simple method of obtaining tissue for histology which does not require much technical skill. The punch is similar to an apple core and comes in a range of sizes from 2 mm to 7 mm diameter. The punch will penetrate the skin to a maximum depth of 7 or 8 mm and so is useful for epidermal and superficial dermal pathology. Shave biopsies are a simple method of getting biopsy specimens, effective for assessing superficial skin disease using a razor or scalpel blade. Ellipse biopsy is useful for the removal of small lesions and for larger areas. Patch testing
Allergic contact dermatitis is a common problem on the lower leg, particularly associated with footwear, medicated dressing and topical therapies. Patch testing assesses this by applying possible allergens to aluminium discs, which are placed onto the skin of the back and left in place for 48 hours. The discs are removed and the skin is assessed on the day and 2 days later. Positive reactions appear as red raised areas within the discs; sometimes the reactions can be very strong, resulting in erosions and blisters.
Recording of the assessment At the end of the skin assessment it is important to ensure accurate recording of the history and examination for a number of reasons: • to ensure good record keeping • to act as a baseline, in case of any changes in the progression of a condition • to facilitate good communication with other medical professionals. The use of colour photography and video equipment may also add objective, recorded evidence and allow the patient with poor mobility /
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
eyesight to visualise and appreciate their skin problem.
Table 9.10
HYPERKERATOTIC DISORDERS
Familial/inherited
Hyperkeratosis is the term used to describe a thickening of the stratum corneum. In the foot, the most common causes are the mechanical forces of pressure, shear and friction acting on the epidermis, leading to corns and callus formation. However, other causes include skin diseases such as psoriasis, dermatitis or fungal infections and the less common palmoplantar keratodermas (Table 9.10). Rarely, a sudden, acquired onset of symmetrical, plantar hyperkeratosis may indicate an internal malignancy.
229
Causes of hyperkeratosis
Cause
Clinical features
Palmoplantar keratoderma
Various types exist. Typically inherited forms begin in childhood
Ichthyosis
Many types. Characterised by dry, flaky skin affecting various parts of the body
Darier's disease
Palmoplantar hyperkeratosis may occur; usually lesions are punctate in form
Pachyonychia congenita
A disease characterised by thickened nails. Associated palmoplantar hyperkeratosis may occur
Acquired
Assessment of corns and callus Corns and callus are a discrete form of hyperkeratosis distinct from the secondary lesions seen with other dermatological disorders. Callus plaques (callosities) are hard, dense, yellowish plaques of hyperkeratotic tissue usually found on the plantar surface of the foot, whereas corns appear as darker, harder, invaginated areas of hyperkeratosis present either alone or within a callus plaque. Patients with calluses and/ or corns complain of a number of symptoms, ranging from cosmetic irritation to severe pain affecting gait. Symptoms include a stabbing pain when walking, which may persist when resting or subside into a dull, soft tissue ache. Callus usually is reported as a stinging, burning sensation, which is worse just after the start of rest and on resuming weightbearing. An illustrative description of callus being like 'walking on stones' may be given. An erythematous 'halo' may be evident around either lesion type. Calluses and corns appear to form in response to over-prolonged and excess mechanical stresses (such as intermittent pressure, shear and friction) from ground reaction forces on the foot and footwear during gait. Corns and callus are always found on areas exposed to mechanical stress and often in a pattern which relates to the biomechanics of foot
Palmoplantar keratoderma
Normally arises in patients from their twenties, in patterns described above
Keratoderma climactericum
Yellow/brown papules, which then coalesce to form thickened plaques across the soles of menopausal women. Fissuring is common
Reiter's disease
Red hyperkeratotic rash may occur on the soles called 'keratoderma blennorrhagica'. Difficult to distinguish from pustular psoriasis
Chronic dermatitis
Hyperkeratotic lesions may be observed accompanied by fissuring and crusting
Pustular psoriasis
Yellow/brown sterile pustules occur with a hyperkeratosis of the palms and soles, typically in older patients
Syphilis
Distinctive copper pink papules may occur on the sole with hyperkeratosis
Lymphoedema
Dirty brown lesions may occur over oedematous areas of the foot and lower leg
Hypothyroidism
A mild hyperkeratosis may occur on the soles but resolves with treatment
Tinea pedis
Hyperkeratosis may occur as part of the eruption
230
SYSTEMS EXAMINATION
function. The few surveys undertaken into the incidence of callus and corn lesions on the foot are in general accordance as to their epidemiological features (Gillet 1973, Merriman et al1986, Springett 1993, Whiting 1987). The commonest sites and lesions include (Fig. 9.5):
101-2 (2nd) 102-3 (4th) 103-4 (3rd) .... 104-5 ·••·(1st) Oiffuse callus
Apices of toes
Site of seed corns
Common site of seed corns Plantar aspect of heel
A
Plantar aspect
2nd toe 3rd toe 2nd 3rd 4th toe 0i'l:--- Subungual 2nd corn 5th toe 1st
B
Dorsum
Figure 9.5 The common sites for corns and callus formation on the feet (Merriman et al 1987).
• diffuse callus beneath the third and fourth metatarsal heads • callus solely beneath the second, first and fifth metatarsal heads • dorsal corns on the fifth toes followed by the fourth, third and second • interdigitallesions between the fourth/ fifth toes followed by first/second and third / fourth toes. Sex incidence ratio is between 1 :2 and 1 :4 male to female, with mode age of symptomatic onset between 40 and 70 years. The incidence decreases with reduced weightbearing and shoe wearing. The site of the lesion, an indication of its severity, size, texture (hard and glassy or soft), duration and stimulators/ exacerbators, e.g. a particular activity and/or pair of shoes, should be noted, along with colour differences and lesion contours, bulk, depth and width. It is assumed that the maceration which appears as a milky yellow region under a callus plaque or corn is due to excess trauma and, as a result, water is squeezed from the viable layers of the epidermis into the lower keratinised layers of the stratum corneum. The features of maceration and extravasation may be considered as clinical indicators of marked mechanical stress (Plate 12). Suitable management of these lesions is urgently required to prevent tissue breakdown and ulceration. Types of corn Seed corns. The aetiology of seed corns is not clear. The empirically proposed association with tension stress has neither been proved nor disputed. These lesions appear similar in structure and biochemically to other mechanically induced hyperkeratoses. Unpublished work using highpowered liquid chromatography (HPLC) shows that they are not plugs of cholesterol as previously thought but, in common with other hyperkeratoses, have a high cholesterol content compared with normal plantar skin (O'Halloran 1990). Seed corns tend to occur at the margins of weightbearing areas of the plantar aspect of the foot either singly or as disperse clusters.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Hard corns. A hard corn (Plate 13) appears as a darker patch within the epidermis, often with a callus covering. Texturally it is hard, glassy and dense when touched with a scalpel. When enucleated, a classic corn nucleus appears as a cone, although they may be any shape or multinucleate. Under greater trauma the contents of the papillary capillaries may be extruded into the epidermis as a brown-black stain (extravasation). A corn forming over a bursa may be associated with the formation of a sinus into the bursal sac; infection may result. Vascular corns. When the skin is made translucent by application of water, alcohol or oil, clinical signs below the surface of the lesion become apparent. Intrusions of vascularised dermal tissue into the epidermis can be seen in vascular corns and, if cut, this vascular tissue bleeds profusely. These lesions usually occur at sites of excess mechanical stress, may have a relatively long history and may be painful on direct pressure. These features suggest that the lesion is a vascular corn rather than a foreign body or wart. Some practitioners make a distinction between vascular and neurovascular corns; others consider that they are one and the same. Soft corns. Soft corns occur interdigitally and appear as soft, soggy epidermal masses (macerated tissue) which can easily blunt the scalpel blade. Pain is a frequent complaint. The condition appears to be caused by poorly fitting footwear, disease processes affecting the skeleton, e.g. rheumatoid arthritis, or biomechanical anomaly, e.g. excess pronation where the toe tissues are compressed and sheared in ill-fitting footwear. Fibrous corns. These arise from long-standing corns and involve the presence of fibrous tissue in the dermis below the corn. The affected tissues have an altered biomechanical behaviour: they appear more firmly attached to deeper structures than normal. Shear stresses occur at the tissue interface and, as this tissue is unable to dissipate stress as efficiently as normal tissue, there may be a perpetuation of what appears to be chronic irritation of tissues, causing further fibrosis to develop. The precise aetiology of these lesions is not clear.
231
Other causes of hyperkeratosis. Palmoplantar keratodermas (PPK) are a complex group of relatively rare disorders which are difficult to classify. Historically, such conditions were named purely on clinical and histological appearance, which has led to a confusing array of nomenclature (Ratnavel & Griffiths 1997). The consistent feature within this group of diseases is hyperkeratosis of the palms and soles. Unlike normal callus, the amount is much increased with a rapid return rate following debridement. Typically, lesions bear no correlation to any weightbearing patterns. Palmar lesions may range from one or two minor patches to complete involvement. The majority of these diseases are hereditary but spontaneous cases can arise. Clinically, PPK may be categorised into one of four distinct patterns of disease:
• diffuse PPK - diffuse hyperkeratosis across the palms and soles (usually sparing the arch) (Plate 14) • focal PPK - discrete patches of hyperkeratosis with normal skin in between • punctate PPK - numerous punctate corn-like lesions spread across the palms and soles • PPK with ectodermal dysplasia - PPK of any variety, with accompanying features of ectodermal abnormalities (e.g. hyperhidrosis, neurological or dental malformations). Many other skin diseases may lead to the development of hyperkeratosis, which often takes on a different texture from the mechanically induced type. For example, in psoriasis the skin may flake off with a scalpel and bleed due to malformation of the epidermis (Au spitz sign). Callus associated with ichthyosis tends to be thick and tough and there will be evidence of the condition on other body sites.
BLISTERING DISORDERS The term blister is used to describe any fluidfilled lesion which may occur as the principal feature of some relatively rare dermatological disease or as a feature of more commonly seen disorders (Table 9.11). Blisters can develop at a number of levels in the skin:
232
SYSTEMS EXAMINATION
Table 9.11
Main causes of blistering on the lower limb
Disorders with blistering as the principal feature
Disorders where blistering may occur as a secondary feature
Epidermolysis bullosa
Friction - most common variety seen on the feet due to pressure and shearing forces
Bullous pemphigoid Pemphigus Dermatitis herpetiformis (rare below the knee)
Fungal and bacterial infections (e.g. tinea and erysipelas) Diabetes - an uncommon complication associated with hyperglycaemia Thermal injury (e.g. burns, cryosurgery) Eczema Erythema multiforme Severe sunburn/photosensitivity
• Superficial. These blisters occur in the stratum corneum and are associated with infections, e.g. tinea pedis. Superficial blisters are more prone to rupture, leaving open erosions which may be complicated by secondary infection. • Intraepidermal. These occur in the lower layers of the epidermis, usually the stratum spinosum, and are associated with, for example, acute eczema and viral vesicles. • Subepidermal. These occur at the dermal-epidermal junction and are associated with, for example, epidermolysis bullosa. Differential diagnosis requires a thorough history and examination (including information on concurrent illness, drug therapies and family history) along with the general pattern and distribution of the disease. Family history is a key feature in epidermolysis bullosa (EB), an inherited group of disorders where the skin reacts to minor trauma by blistering; hence the feet are commonly involved. The spectrum of the disease ranges from EB simplex (minor blistering of the hands and feet with minimal scarring and little nail involvement) to a potentially lethal recessive dystrophic form (with more widespread blisters and scarring). As the disease is inherited, the onset is usually in childhood. Epidermolysis bullosa acquisita is an
acquired form, akin to EB simplex, which normally affects middle-aged patients with a similar pattern. Pemphigus is a relatively rare blistering disorder seen in middle age. Lesions tend to be intraepidermal (which rupture easily) and have an insidious onset often without a history of trauma. Unlike EB, pemphigus rarely affects the feet but oral lesions may be present. In both conditions, Nikolsky's sign may be present - the ability to raise a blister when firm finger pressure is applied across the affected skin. Bullous pemphigoid (Plate 15) is distinctive in that it usually affects the over-sixties with large tense subepidermal blisters emerging on urticated skin, including the foot. Mucous membrane involvement is not a common feature. Typically seen on the extensor surfaces but rarely below the knees is dermatitis herpetiformis. Blisters are typically small and grouped, with the appearance of herpetic lesions. Pruritus is a common early symptom. Unlike pemphigus, oral lesions are not observed, but the majority of sufferers have also coeliac disease of the jejunum.
INFLAMMATORY CONDITIONS OF THE SKIN Eczema Eczema is a descriptive term encompassing a wide variety of inflammatory diseases, many of which are pertinent to the lower limb. Clinical features vary greatly between each form of eczema and so are presented separately. Subtypes of eczema Atopic dermatitis. This increasingly common form of eczema presents at any age but is most common in childhood. Itch is the main symptom, with rash localised to the flexures. The itching and subsequent scratching can be severe. In some patients dryness and scaling is the major feature. Patients often have other allergic diseases such as hay fever or asthma. The signs are all manifestations of scratching and rubbing. First, the skin roughens and
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
reddens; with continued scratching the skin becomes broken and later infected. The usual pathogen is Staphylococcus aureus, which produces golden weeping and crusted skin. Later, the skin thickens with accentuation of the normal skin folds (lichenification), with fissures developing where the skin is less flexible. Asteatotic eczema. This is a common form of eczema usually seen in the elderly, especially those in institutional care. It results from low humidity, poor rinsing of soaps or detergents or over-vigorous washing. The usual symptom is soreness and itching, most frequently on the shins. The skin is scaly, pink and the surface broken in a crazy paving pattern. Discoid eczema. Discoid eczema is a very localised form of eczema. It presents as multiple, isolated, and coin-shaped lesions. Usually patients will complain of itching and, because of the shape of the lesions, assume they have a fungal infection. On examination, the lesions are red, scaly and superficially infected with golden crusting. Patients generally have dry skin or a previous history of eczema (Case history 9.2).
------------l Case history 9.2 Emma was a 24-year-Old student nurse and was referred for treatment of her ingrowing toe nail. She mentioned that her main symptom was itching rather than soreness. She had wondered whether it was a fungal infection. She had bought some antifungal cream and had been using it for 3 weeks. She was concerned, as the toe appeared to be worsening and her 'infection' was spreading. She was otherwise well, apart from a childhood history of hay fever and eczema. She was currently living in the hospital nursing residence. On examination, the nail appeared normal although the nail bed was inflamed in relation to a 2 cm circular patch of redness and scaling. She had a number of similar lesions on her lower legs and some appeared infected. Her skin was generally dry. Diagnosis: Diagnoses considered at that time were ringworm (fungal infection), although the culture and microscopy were negative; Bowen's disease, although Emma was really too young for this and had not had much sun exposure; and psoriasis, but she did not have a family history or other signs of psoriasis. Finally, a diagnosis of discoid eczema was made. Emma used a weak steroid and moisturiser, which cleared her symptoms quickly, and her skin returned to normal.
233
Lichen simplex. In this condition, patients usually complain of one or two itching patches. It frequently occurs on the medial aspect of the ankles and lateral calves. The itching may be very severe and keep the patient awake at night. The skin reacts to the scratching and rubbing by becoming thickened and lichenified (see above). Sometimes the lesions resemble plaques and other times nodules. The lesions are usually pink or brown and may be mistaken for lichen planus or psoriasis (see below). Stasis dermatitis (venous eczema, gravitational eczema). This form of eczema affects the lower
legs. It usually occurs in patients with venous disease (previous varicose veins or deep venous thrombosis). Patients will complain of itching or soreness and may have a history of previous venous ulceration. The skin is red, scaly and weeping, usually in association with an ulcer or area of varicosity. The underlying skin may feel firm and be discoloured blue brown with previous leakage of blood into the skin. Occasionally, the rash can spread beyond the areas of venous disease. One should always consider allergic contact dermatitis, as this is a common secondary feature. Pompholyx. This is an acute eczema of the palms and soles. It is usually associated with a number of different forms of eczema elsewhere. As the plantar skin is so thick, instead of the skin weeping when it is inflamed, it forms small blisters under the skin instead. These can occasionally be mistaken for eczema elsewhere.
Psoriasis This is a very common group of diseases. In its most usual form, it consists of well-defined, red plaques with loosely adherent silvery scale localised to the extensor surfaces. Two percent of the population is affected and may present at any age but the second and third decades are the commonest. Scaly areas develop over weeks or months in the scalp, around the sacrum and umbilicus. The flexures and genitals may be affected. The nails have characteristic changes that are a useful aid to diagnosis: they develop pitting and ridging. The nail may come away
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SYSTEMS EXAMINATION
from the nail bed (onycholysis) and the undersurface of the nail can develop thick scaling. The damage is only transient. Arthritis is commonly associated with psoriasis and may take on a number of forms. Disease severity of the arthritis does not parallel the extent of the skin disease. Psoriasis and its variants commonly affect the lower legs. Subtypes of psoriasis Classic plaque psoriasis. This symmetrical rash affects the extensor surfaces of the skin. On the lower leg, the knees and shins are frequently involved and in this site may be thick and persistent, covering the whole shin. The plaques are variable in size, pink, red or purple and well demarcated. The scales are large and silver in colour and can be easily scraped away, revealing pinpoint bleeding. Usually nail changes will be evident on the toes. Guttate psoriasis. This acute variant follows a streptococcal sore throat. Within a couple of weeks, small innumerable plaques of psoriasis cover the body. The rash tends to resolve with no treatment in 2 to 3 months. Occasionally it can be recurrent or go on to develop into classical plaque type. Palmar plantar pustular psoriasis (Plate 16). This variant occurs primarily in middle-aged, female smokers. It is characterised by pustules on the palms and soles, with or without classical disease elsewhere. The pustules initially are creamy coloured; as they mature, they turn brown; finally, the roof falls away, leaving a scaly depression. They are commonly mistaken for fungal or bacterial disease but culture of the pustule is always sterile. A single digit may be all that is involved; in this form, the nail may be destroyed permanently. Smoking cessation does not help the rash. Generalised pustular psoriasis and erythroderma. Occasionally, psoriasis may be pustular
on the body. In this form, it is widespread, of acute onset, often with systemic upset. Lakes of pus can develop on the skin which later scale. Patients usually have a previous history of psoriasis. Occasionally, psoriasis can be so wide-
spread it affects the whole body. With this, there is loss of normal skin function (barrier against infection, heat and water loss) and patients can become very ill (death is not unknown, usually due to coexisting conditions). This is called erythroderma.
Vasculitis This condition frequently presents on the lower legs. The rash may have been precipitated by a new medication or an infection or another inflammatory medical condition. Clinically, there is inflammation within the blood vessels that results in leakage of blood into the surrounding skin. Lesions do not blanch. Early lesions are raised, red and itchy. Later, the skin may blister or ulcerate. Occasionally, the rash may be very extensive; commonly, it is modified by areas of pressure and may be accentuated around the shoe or sock line. Apart from ulceration, skin involvement is usually only a minor problem. Generalised involvement is sometimes a problem, with inflammation of vessels occurring in the gut, joints and kidneys that occasionally may result in renal failure or, rarely, death.
Lichen planus (Plate 17) Lichen planus (LP) is a common inflammatory condition that frequently affects the lower leg. The main presenting symptom is itch and rash. The itch is often very severe; patients tend to rub more than scratch, as sometimes the rash is tender. The rash may be very widespread, appearing characteristically on the wrists, shins and sometimes diffusely on the body. The mouth is often sore; the genital mucosae can be involved. Scalp involvement may lead to permanent hair loss. The nails are also involved. The clinical appearances are classical. The rash consists of multiple flat-topped, polygonal papules that have a shiny surface. The colour is pale pink through to violet and sometimes brown. Resolving lesions often leave marked persistent pigmentation. Nail involvement produces pits on the nail surface; later, the nail thins and becomes abnormal, sometimes resulting in destruction of
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
the nails. Inside the mouth, LP can appear as white lacy streaks on the mucosa to blisters to ulcers. On the lower leg, LP can become very thick (hypertrophic). LP frequently develops in areas of skin injury (koebnerisation), leading to bizarre linear forms of the rash. LP of the soles is less distinct, but the symptoms are similar and usually associated with more typical rash elsewhere. Lichen planus is usually relatively shortlived 0-2 years), but hypertrophic disease may become chronic.
Granuloma annulare Frequently misdiagnosed as tinea, this eruption is an idiopathic disorder that predominantly affects people under 30 years old (particularly children). Starting as a single red papule, it spreads concentrically (up to several centimetres in some cases), becoming concave in the centre with a pink papular edge. The lesions, which can be single or multiple, occur most commonly on the hand but also occur on the foot and shins. Unlike tinea, the lesion is rarely scaly and does not itch. Diagnosis is confirmed by biopsy. The condition may be rarely associated with diabetes mellitus. Necrobiosis lipoidica may resemble this lesion but tends to have a yellowish hue.
Necrobiosis Iipoidica (Plate 18) This condition occurs on the shin and is commonly seen in diabetics. Patients may be asymptomatic or complain of rash or ulceration. The lesions start as red patches, which enlarge, the centre becomes depressed and the skin yellows. Blood vessels may be visible traversing the patch. Occasionally, lesions ulcerate. Sometimes the rash may precede the diagnosis of diabetes or rarely may be the presenting feature. They are often multiple.
Other inflammatory conditions Sunburn. Exposure to sunlight (UVB radiation) will lead to an erythema after a latent period of 1-3 hours, depending on the amount of exposure. Excessive exposure can lead to
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desquamation (peeling) and, in the long term, can increase the risk of malignant changes in the skin. Chilblains (perniosis). This is a familial vasospastic response to prolonged exposure to cold. Typically, lesions begin on the apices of the toes, fingers and occasionally the ears. In women, lesions may appear in the region just above the footwear line where the ankle is only covered by thin hosiery (sub malleolar perniosis). The chilblain begins as an erythema, turning into a purple, swollen lesion that may itch and burn. Ulceration of lesions is not uncommon. Erythrocyanosis. A relatively common disorder, erythrocyanosis commonly affects young, overweight women, particularly those working in a cold environment. Exposure to cold invokes a vasospastic response, resulting in a purple-red discoloration in the buttock, thigh and shin area accompanied by a burning sensation. Erythema multiforme. This skin disorder is characterised by symmetrical, concentric 'target' lesions occurring on the hands, feet and limbs. Individual lesions may have a blistered bluishred centre with a more vivid surrounding erythema. Involvement of the genital, oral and conjunctival areas is not uncommon and appears in the more severe form of the disease known as Stevens-Johnson syndrome. The causes are diverse, but 50% of cases are idiopathic: known causes include drug eruptions and viral and streptococcal infections. Differential diagnosis should include other causes of blistering and fungal infections. Negative fungal culture and the symmetry of the eruption should establish the diagnosis.
ALLERGIES AND DRUG REACTIONS Allergic contact dermatitis (Plate 19)
Typically, this condition occurs as a result of the skin becoming sensitised to a specific allergen (a type IV hypersensitivity reaction), so that subsequent exposure to the allergen produces an acute reaction of erythema, weeping and blistering at the point of contact.
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The site of the reaction depends on the area of skin exposed to the allergen. Sensitisation is more rapid on thin or moist skin; hence, reactions are most commonly seen on the face and antecubital fossa. Due to its thickness, the plantar surface of the foot rarely becomes involved. Shoe line eruptions tend to be seen on the margins where the skin becomes thinner towards the dorsum. The popliteal fossa is also an area of thinner skin and, occasionally, may show reactions: e.g. to the dyes used in nylon tights. The common allergens affecting the lower limb are listed in Table 9.12. It is important to recognise that sensitised T cells may spread from the contact site and provoke eczematous type lesions elsewhere on the body. When the cause of the reaction is not apparent, patch testing should be undertaken to identify the causative agent. Differential diagnosis should be made from psoriasis and fungal infections. Depending on the point of exposure lesions may be symmetrical or asymmetrical with a well-defined edge. Fungal cultures and microscopy will typically be negative. Allergic dermatitis rarely affects children and the elderly, possibly due to a less vigilant cell-mediated immunity. With psoriasis, lesions should be present elsewhere and nail changes are likely. Juvenile plantar dermatosis
Juvenile plantar dermatosis is thought to be a variant of contact dermatitis. The condition arises in schoolchildren as a scaly, erythematous, glazed eruption, typically affecting the forefoot Table 9.12
Common causes of allergies in the lower limb
Location
Common allergen
Thigh (pocket area)
Phosphorus sesquisulphate (matches)
Popliteal fossa
Dyes in nylon tights
Foot and ankle
Venous leg ulcer treatments Chromates (leather tanning) Adhesives (epoxy resins) Metals (nickel in buckles) Medicaments, especially those containing lanolin and parabens
and plantar surfaces of the toes, sparing the interdigital areas. Fissuring may accompany the condition. Differential diagnoses include tinea infection, psoriasis, contact dermatitis and adverse drug reaction. The symmetry and glazed appearance of the condition, along with the patient's age, are usually enough to make the diagnosis. With a contact dermatitis, a positive patch test would be obtained. Drug reactions
Reactions to drugs may arise due to: • a true allergic reaction to a drug (hypersensitivity) • the effects of overdosage (toxic reaction) • side effects of a drug • alteration, by the drug, of the normal immune response. The difficulty in differentiating the above factors is that, potentially, they can all mimic virtually any skin lesion. When a drug reaction is suspected, a thorough drug history is required (including any over-the-counter preparations the patient may be using). Most often the offending drugs are the ones taken in the last 2-3 weeks, although reactions are not uncommon in drugs taken safely for many years. Withdrawal from the drug usually results in resolution of the condition within a week or two. Drug reactions affecting the lower limb are rare. Typical patterns of drug eruptions include: • toxic erythema - generalised erythema accompanied by fever • urticaria • erythema multiforme • vasculitis - typically seen as a painful purpura on the shins • erythema nodosum.
INFECTIONS OF THE SKIN The surface of the skin is an effective barrier against most environmental agents, but through injury to the skin surface or when exposed to virulent organisms this barrier fails. The pattern of
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
disease is very much dependent on the type of infection and so will be considered accordingly.
Viral Verrucae. Verrucae (Plate 20) are the predominant viral infection on the foot caused by infection of the skin with human papilloma virus (HPV). Around 5% of 16 year olds will have warts at anyone time (Williams et al 1991). The virus affects the stratum spinosum and causes hyperplasia and formation of a benign tumour. Typically, the plantar wart is found under a point of high pressure, e.g. the metatarsal heads or a bony prominence (Glover 1990). In its early stages it appears as a small, dark, translucent puncture mark in the skin. More mature lesions show thrombosed capillaries, a 'cauliflowerrough' surface and are painful when pinched. The patient may complain of increased discomfort on starting to walk after a period of rest, e.g. first thing in the morning. Different types of HPV cause different wart lesions, e.g. flat, genital or plantar. Verrucae protrude above the level of the skin unless they occur on weightbearing surfaces. When they are found on weightbearing surfaces they protrude into the skin and, as a result, are more painful. Mosaic warts are made up of multiple, small, tightly packed individual warts and may not be painful, whereas plantar warts may be single or multiple and are usually painful. Occasionally, periungual warts may develop around the nail edge and lead to distortion of the nail plate. Verrucae can usually be diagnosed from their clinical appearance; however, they can be confused with corns (particularly neurovascular or fibrous) and foreign bodies. Verrucae can occur on non-weightbearing and/or weightbearing areas of the foot, unlike corns and most foreign body injuries, which tend to occur solely on weightbearing areas. There may be multiple verrucae present, not only on the feet but also on the hands, the pinching of which tends to cause a sharp pain, whereas corns and foreign bodies give rise to pain on direct pressure. Verrucae appear encapsulated and the skin striae are
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broken; corns do not appear encapsulated and the skin striae are not broken but pushed to one side. Any wart with an atypical appearance, particularly in the elderly or immunosuppressed, should be biopsied as, rarely, the lesion may undergo malignant change. Molluscum contagiosum. This is a contagious infection (usually of children) which usually involves the trunk but can affect the leg and foot. Infection with the causative poxvirus, usually by close contact, leads to a papular lesion, which may range in size from a pinhead to a pea. The hard, shiny pedunculated lesion has a central crater from which cheesy material may be expressed by pinching it. The uniqueness of this lesion makes the diagnosis straightforward. Herpes zoster (shingles). Shingles is a recrudescence of previous chicken pox, usually along a single dermatome. It can occur at any age, but most frequently in the elderly or immunosuppressed. It presents as a 1-3-day history of pain or burning in one limb followed by haemorrhagic blisters and later superficial ulcers. Pain may persist for many weeks and months. Herpes simplex. Herpes simplex (cold sores) rarely affect the lower leg, although they may involve the thigh in rugby players (serum pox) following infected oral exposure to an eroded area of skin on the sports field.
Bacterial Bacterial superinfection, which is very common particularly in the various forms of eczema, was discussed earlier. Primary bacterial infections are less common (Plate 21). In all these conditions, full assessment by bacterial swabs is essential. Ecthyma. This infection affects the full thickness of the epidermis. The main pathogens are Staphylococcus aureus and Streptococcus pyogenes. The patient may have recently been to a humid climate or had an insect bite. It presents as a shallow ulcer with a thick, crusted top. Cellulitis. Cellulitis or erysipelas is a serious infection usually of the lower leg caused most commonly by Streptococcus pyogenes. It presents as a flu-like illness that is rapidly followed by a painful red advancing area, usually on the lower
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leg. The affected area becomes swollen and the skin discoloured. The skin may even blister, necrose and ulcerate. Commonly, a 'portal of entry' is found such as tinea pedis (see below) or a fissured patch of eczema. Pitted keratolysis (Plate 22). Bacterial overgrowths on the sole of the foot secrete proteolytic enzymes that produce multiple pits within the epidermis. The pathogens are microaerophilic diphtheroids. This is particularly common in patients with sweaty feet or who wear trainers. Usually it is asymptomatic, but sometimes the skin thins sufficiently to be tender. Odour is commonly offensive in such patients. Erythrasma. This bacterial infection of creases and flexures occurs between the toes of the foot. It is commonly mistaken for tinea pedis. The pathogen is Propionobacierium minutiesimum, The skin is usually macerated and red/brown in colour. Again, it has a strong odour and fluoresces coral pink in Wood's light.
Fungal There are four patterns of fungal infection of the foot (tinea pedis). Asymmetry is a feature common to all subtypes. In all situations, scrapings are essential to fully assess for fungal disease. Interdigital scaling is the commonest form, usually presenting as itching and fissuring. This usually occurs between the third to the fifth toes where the skin is most macerated. The rash initially begins on one foot, only later extending to the other toes, nails and other foot. A variety of fungi and yeasts are implicated. Extension onto the dorsa of the foot (Plate 23). In chronic disease, the fungus can spread onto the dorsa of the foot, producing itchy scaly rings with an active edge. Fungal culture will help differentiate this from discoid eczema. Typical fungal causes include Trichophyton rubrum and less commonly Epidermophyton floccosum. Blistering in the instep. The inflammatory reaction on the sole to fungus tends to produce blistering (Trichophyton mentagrophytes). It is usually unilateral. Removal of the blister roof will allow closer inspection and it may be sent for culture.
Moccasin foot. The soles of the foot can be generally involved with fungus (Trichophyton rubrum), producing thickened scaly feet. Often the disease affects both feet. The nails may also be involved. Most patients are unaware of the problem but will have a previous history of infection. Onychomycosis. Tinea pedis may progress to the toe nails (onychomycosis), typically as a result of repeated trauma (e.g. from footwear). Infection may occur superficially on the nail plate or subungually invading under the hyponychium. Proximal subungual involvement occurs rarely in immunocompromised patients or following chronic paronychia. Total nail involvement and dystrophy may result. Tinea incognito. Misdiagnosis of fungal infection is a problem as often the incorrect diagnosis made is eczema. The use of topical steroids to reduce inflammation consequently allows the unsuspected fungus to grow unchecked by the immune system. Patients present with a history of a persistent rash, usually on the foot, which fails to respond to steroid creams. The potency of the steroid used is often very high. The rash is red, ill-defined with nodules within, that when squeezed express pus. Scrapings confirm the presence of fungus (Case history 9.3).
INFESTATIONS AND INSECT BITES Scabies. The mite Sarcoptes scabiei causes scabies. Itching is often severe despite sometimes having minimal evidence of infestation. Patients may describe itchy nodules or blisters. They will usually have family members presenting at the same time with itch. The signs are generally that of eczema but blisters and excoriations are more pronounced. The primary lesion is the burrow of the mite. It appears as a linear or serpiginous white line with scaly opening at one end and a minute grey or red dot at the other end (the mite). The mite may be extracted with a needle and examined using a microscope. Scabies should be suspected in any patient with a pronounced itch, and other sites of involvement (hands and trunk) should be sought.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Case history 9.3 Philip was a 25-year-old footballer who presented with a 4-year history of a troublesome right great toe nail. He was concerned, as the nail was discoloured and growing abnormally. A brief examination of the toe nail suggested fungal disease. Philip explained that since playing professionally he commonly developed a blackened nail on his right foot but recently the colour of the nail had changed and become crumbly. He also mentioned that from time to time he had athlete's foot but had never sought treatment for this. Initially, when asked what medication he was on, he said none; then he remembered that he had been using some steroid cream. A friend had given him some that he used rather unsuccessfully, to treat a patch of eczema on the same foot. On closer questioning, it seemed that the cream had initially helped the eczema but each time he stopped the treatment the eczema just came back again. On examination, the nail was grossly thickened with creamy linear discoloration at the medial margin extending to the proximal nail fold. The ridged nail was detaching itself from the nail bed. The fourth and fifth interdigital spaces on both feet showed scaling and blistering. Examining the right ankle revealed a thickened erythematous scaly plaque within which were inflamed nodules. The area was markedly excoriated. Microscopy of scrapings from the web space and eczematous plaque revealed the presence of fungus. Culture of the toe nail clippings grew the same fungus, Trichophyton rubrum (a common fungus affecting the foot). Diagnosis: Fungal nail and web space disease with tinea incognito of the ankle. The whole problem cleared after discontinuing the topical steroid and a 3-month course of antifungal tablets (terbinafine). He was also advised to check the fitting of his soccer boot.
Insect bites. A variety of insects will bite the skin, producing itch or painful nodules or blisters on the skin. The lower leg is commonly involved as it is often exposed (biting insects and fleas). Clues to suggest insect bite are grouped lesions, often along a sock or shoe line, and a history of presence of domestic animals or proximity to farms. Larvae migrans. A variety of hookworms that are gut parasites in animals may find themselves in humans. Cats and dogs are the main carriers. The immature form of the parasite penetrates the skin and the larvae migrate under the skin to produce loops and tortuous tracks.
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Patients usually complain of itch and blistering, usually contracting the disease on beaches abroad but occasionally in the UK. The pattern of migration makes diagnosis easy. Fortunately, the disease is self-limiting.
DISORDERS OF THE SUBCUTANEOUS TISSUE The subcutaneous layer is a layer of primarily adipose (fat) tissue and covers most of the lower limb, particularly the thighs, anterior shins and plantar surface. Atrophy. Atrophy is the most common disorder affecting the subcutaneous layer. It occurs most frequently as a result of ageing and trauma (e.g. heel pad atrophy in long-distance runners and the elderly) or as a result of granulomatous change (panniculitis) around injection sites (typically, diabetic patients using insulin injections). Affected skin becomes depressed and scarring may occur. Painful piezogenic papules. On the plantar surface, around the heels, herniations of fat from the heel pad into the dermis may be evident on standing. As solitary or multiple nodules they may occasionally give rise to heel pain (Shelley & Rawnsley 1968), usually in middle-aged females. Diagnosis is established, as pain will result from direct pressure while standing, but when nonbearing the lesion completely disappears. Erythema nodosum. This is an uncommon eruption affecting the shins presenting as painful nodules on the shins and less commonly the thighs and forearms. The rash starts as painful areas that enlarge into hot, red nodules, which are acutely tender. These then resolve over a matter of weeks. The redness fades and takes on a bruised appearance. The condition is important, as it is often associated with other diseases such as sarcoidosis and a variety of infections.
SYSTEMIC DISORDERS AND THE SKIN The skin is an easily accessible structure and may often give clues regarding internal disease.
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SYSTEMS EXAMINATION
Typical disorders which may affect the skin include connective tissue and endocrine diseases. Common systemic disorders and their effects on skin are summarised in Table 9.13.
PIGMENTED LESIONS Pigmented lesions represent a large part of general dermatological practice; this is also the case on the lower legs. Pigmented lesions arise as a result of a variety of processes, both neoplastic and inflammatory. Close attention to the clinical history and signs will allow distinction between most lesions. Freckles or ephelis. These are probably the most common pigmented lesions seen on the skin. They are most common in those with fair skin who have been exposed to sunshine. Lesions are usually innumerable; they are visible but not palpable and the pigmentation within is usually evenly distributed and is generally slight. Darker
freckles can also occur, particularly after prolonged or excessive sun exposure. Lentigo. A lentigo is a lesion where there is an increase in the number of melanocytes within the skin, resulting in a pigmented patch. Lesions usually occur in older patients and usually arise on sun-exposed sites. Again, the lesion is visible and not palpable; it tends to be solitary and the pigmentation within it is usually light and always even. Seborrhoeic warts. These are particularly common, developing with advancing age. They appear as well-defined, rough, warty, slightly raised lesions that have a stuck-on appearance. They usually occur on the trunk and proximal limbs but can arise on the lower leg. They do not develop on the sole. They are always benign but can become inflamed after minor trauma and may be mistaken for malignancy. Pigmented naevi. Moles are collections of pigmented naevus cells (melanocytes) in the skin
Table 9.13 Systemic conditions and their associated skin changes Condition
Associated skin changes in the lower limb and foot
Diabetes mellitus
Increased incidence of skin infections (fungal and bacterial), skin stiffening, ulceration (neurovascular), diabetic bullae, necrobiosis lipoidica, granuloma annulare
Lupus erythematosus
Erythematous scaly plaques with follicular plugging
Systemic lupus erythematosus
Periungual erythema, splinter haemorrhages, onycholysis and leuconychia. On the legs, erythromelalgia and erythema nodosum
Dermatomyositis
Periungual erythema with characteristic 'ragged cuticles'. Occasional calcification within the skin
Systemic sclerosis/scleroderma
Tight waxy skin with later distal digital atrophy with calcinosis, ulceration and occasionally gangrene
Ehlers-Danlos syndrome
Fragile skin with frequent bruising, hypermobility, poor wound healing, typically showing large scars upon the knees
Rheumatoid arthritis
Skin atrophy, nodules, vasculitis with periungual infarcts, splinter haemorrhages and onycholysis with longitudinal ridging of the nails
Hyperthyroidism
Hyperhidrosis, clubbing, onycholysis, hyperpigmentation, pretibial myxoedema
Hypothyroidism
Anhidrosis, leuconychia, pruritus, palmar and plantar hyperkeratosis
Acromegaly
Hyperhidrosis, skin thickening, coarse hair
Hepatic disease
Clubbing, spider naevi and pruritus
Renal disease
Hyperpigmentation or skin yellowing, nail changes - half-and-half nails, onycholysis
Reiter's syndrome
Keratoderma blennorrhagica
Internal malignancy
Hyperpigmentation, palmoplantar keratoderma, secondary skin tumours, pruritus, nail clubbing, bullous eruptions
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
that contain the pigment melanin. The nature of moles will vary enormously depending on how many naevus cells are present, where in the skin they occupy and how pigmented they are: obviously, the greater number of naevus cells there are, the larger and more protuberant the lesion. Lesions that are close to the epidermal surface tend to be red/brown in colour; however, the further down the pigment is in the skin the bluer the colour becomes. In addition, the intensity of the colour will depend upon how much pigment is being produced. Moles are sometimes present at birth; their number increases during life, most commonly in the first two decades but can develop at any age. Moles may become larger and more pigmented with age and occasionally may regress. The clinical appearances of moles are infinitely variable, therefore making classification on macroscopic grounds alone almost impossible; however, they can be defined according to their microscopic appearances and knowledge of these patterns may be useful in the clinical setting. Junctional naevi. Collections of melanocytes along the dermal-epidermal junction, junctional naevi are the usual type of mole for the sole of the foot. In this site the pigmentation usually follows the ridges and troughs on the epidermal markings. They are usually impalpable, the colour is red brown, and is symmetrical. They commonly occur in children and generally 'mature' by melanocytes falling away into the dermis, forming intradermal naevi. Here, the melanocytes have all fallen into the superficial dermis. Often, the naevus cells stop producing pigment and plump up. Clinically, the lesions are therefore protuberant and pale or skin-coloured. They may continue growing in adulthood. Compound naevi have both junctional and intradermal components and therefore share clinical features of both types of lesions. Blue naevi. Melanocytes that have never reached the epidermis and instead have proliferated in the deeper dermis have a blue appearance. These often develop in later life, especially on sun-exposed sites, especially the dorsa of hands and feet and on the scalp. Blue naevi are small (less than 5 mm) and may be slightly
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raised. They can be differentiated from vascular malformations in that they do not blanch. They are almost always benign. Malignant melanoma (Plate 24). In the assessment of pigmented lesions the potential diagnosis of melanoma should always be considered. There are a number of clinical symptoms and signs that should alert you to the diagnosis (Table 9.14). Itching is an early and significant symptom that should be sought. Often, it may be the only presenting symptom, particularly where the melanoma is not in general view. There may be a change in the surface of the mole, skin creases may be lost, and hair follicles and pores may disappear. Almost always there will be an increase in the size, shape or thickness of the mole. This occurs over weeks and months and usually is asymmetrical. Colour will change within a mole; pigment can both increase and decrease within the same lesion. Also, as the melanocytes invade deeper into the skin, they may appear blue or even black. Rarely, melanoma may lose all pigmentation, making diagnosis very difficult clinically (although the patient may recall a pre-existing pigmented lesion). Bleeding, the surface of a melanoma may ulcerate, particularly in advanced disease. The tumour may have spread by the time it is picked up; this may be clinically evident with tumours developing along the lines of lymphatic drainage (in transit metastasis), in the draining lymph nodes or at distant sites (for instance presenting as fits, weight loss or shortness of breath). Melanoma is very rare before puberty and usually occurs in large congenital moles. The
Table 9.14 Suspicious signs and symptoms in a pigmented lesion
Symptoms
Signs
Change in sensation Change in size Change in colour Change in shape Change in outline New lesion
Loss of skin markings Irregular margins lrreqular pigmentation Bleeding Ulceration
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SYSTEMS EXAMINATION
majority of melanomas develop in later life, occurring in fair individuals on sun-exposed sites and most commonly in women on the lower legs. Melanoma may arise on the sun-protected sole of the foot and, as it is hidden from view, it usually presents late. Any unusual lesion on the foot should be suspected, particularly if there is pigmentation (Case history 9.4).
SKIN TUMOURS Tumours of the skin need careful assessment, as there will be clues in both history and examination that will lead to accurate diagnosis. Most lesions will be benign, but a small proportion will be malignant (Table 9.15) and therefore life threatening. Early referral of such lesions to a dermatologist can improve prognosis enormously. Points that should be sought in the history are, obviously, site of the lesion, how quickly it is growing, whether there are associated symptoms such as irritation or pain, or whether there are similar lesions elsewhere. Clinical signs that should be recorded are size, shape, surface, colour, outline, temperature and consistency. Dimensions should be recorded in the notes, and where possible the lesion should be photographed.
Case history 9.4 Amiddle-aged female patient presented for assessment of her softcorns, which had been troublesome for many years.After taking a history, the feet were examined, revealing trivial disease; however, on her posterior left calfthere was a suspicious pigmented lesion. On questioning the patient, she remembered having a mole on her leg for a number of years but apart from occasional minor irritation itcaused her no concern. She tended to burn when she was inthe sun and had spent the first 20 years of her life living in Florida. She did not have anyfamily history of melanoma. She was otherwise well. On examination the lesion was 1.5 em in diameter, the pigmentation was varied and the outline irregular. Within the lesion there was a nodule which had become ulcerated. She was referred to a dermatologist, who confirmed the suspected diagnosis of melanoma by an excision biopsy. She remains free from recurrence.
Table 9.15
Principal tumours affecting the lower limb
Benign
Malignant
Dermatofibroma Seborrhoeic wart Haemangioma Lipoma Clear cell acanthoma Pyogenic granuloma Eccrine poroma Glomus tumour
Bowen's disease Basal cell carcinoma Squamous cell carcinoma Melanoma Kaposi's sarcoma Porocarcinoma Metastasis
Benign tumours Dermatofibroma. The lesions are very common, particularly on the lower leg. They are usually symptomless; often the patient is unaware that the lesion is even there. Sometimes they catch when the leg is scratched or shaved. They are felt as firm tethered nodules within the skin, sometimes with a slightly elevated surface. They often have a pigmented halo and for this reason may be mistaken for more sinister lesions. They are always benign. Pyogenic granulomas (Plate 25). These are common vascular proliferations that grow rapidly over a few days or weeks. They usually follow a minor injury. The surface is very easily broken and bleeding may be prolonged and frequent. In time, the lesion develops a surface epithelium that is more resilient, ultimately resembling a haemangioma. Eccrine poroma. These are benign tumours of the sweat duct that arise on the palms and soles, typically in the over-40 age group. They are pink or red, painless and usually 1-2 em in diameter with a moist surface, surrounded by a moat-like depression. Occasionally, they can undergo malignant change.
Malignant lesions Bowen's disease. Bowen's disease is squamous cell carcinoma confined to the epidermis only. It is a condition of the elderly, usually pre-
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
senting as a well-defined, erythematous, scaly patch on the lower leg. When the scale is picked off the surface may bleed and weep. It occurs most commonly in women (suggesting a sunrelated aetiology). The lesions are sometimes multiple. Left untreated they may persist for many years; however, sometimes this disease can progress on to true invasive squamous cell carcinoma. Basal cell carcinoma. Basal cell carcinoma usually presents on the face but occasionally it occurs on the lower legs. Usually it presents as a fleshy nodule with a pearlescent appearance, having small blood vessels grossing the surface. Advanced lesions ulcerate and if neglected may become very large. Despite being locally destructive they do not metastasise. Occasionally, they remain superficial and indistinguishable from Bowen's disease. Squamous cell carcinoma. Squamous cell carcinoma (See) is a common malignant tumour of the lower leg presenting as a lump or as a bleeding ulcer. The tumour grows over a period of weeks and months. In time the tumour becomes painful, particularly if it is invading bone or nerves. Usually it will develop on a background of sun damage but it is also associated with exposure to arsenic and aromatic hydrocarbons. Occasionally, it may develop with an old scar or leg ulcer; this should be considered, especially in ulcers that fail to heal with conventional measures or ulcers with fleshy or rolled edges. Metastasis generally tends to be a late event, usually to the regional lymph nodes. An see that arises on the foot may invade deeply with only minimal surface involvement, mimicking pressure or neuropathic ulcers. Often, in this site the tumour will have multiple sinuses that discharge offensive-smelling material. Kaposi's sarcoma. This rare vascular tumour was described originally on the lower leg in males of eastern European extraction. It presents as blue-black or purple patches that later become plaques and nodules. Tumours range in diameter from 1 to 3 cm; they are usually multiple. Later lesions may involute or ulcerate. Oedema may become a problem. Kaposi's sarcoma is associ-
243
ated with human herpesvirus 8 and immunosuppression, notably HIV (Lebbe 1998). Porocarcinoma. This rare sweat duct tumour often occurs on the lower leg. The history and clinical appearances are similar to see but the tumours are more likely to recur and metastasise. Metastasis (Plate 26). Tumours of the lung, prostate, thyroid, kidneys and breast rarely spread to the skin. Usually when they do, it tends to be the scalp and upper body. However, tumours arising on the lower legs can metastasise to the draining lymph vessels and nodes, particularly melanoma and Sec. The tumours will usually appear as subcutaneous nodules; they may be large. They may be firm and may feel as if they are attached to related structures. The patient will usually have a history of previous tumours, but occasionally the metastasis may be the presenting feature.
SUMMARY There is no point assessing a patient's skin unless the information is to be used to benefit the patient. A diagnosis is formulated from all the data gathered from the assessment and the practitioner's knowledge and clinical experience. Epidemiological data - information such as age and gender - may help. Information from observation, clinical tests and special investigations will also help to reduce the list of possible conditions. In most instances the diagnosis will become obvious, but on occasions it may not be possible to reach a definitive diagnosis. In this case a provisional diagnosis has to be made and the cycle of the disease process must be awaited for further enlightenment. Where a diagnosis is not available, the practitioner may decide to treat the symptoms. Occasionally, the effect of a treatment can be a diagnostic aid in itself; e.g. a vesicular eruption that resolves with the use of an antifungal implies that the aetiology was mycotic. When a condition is diagnosed, the practitioner must decide what action is necessary based on available evidence.
244
SYSTEMS EXAMINATION
REFERENCES Baran R, Dawber R P R, Tosti A, Haneke E 1996 A text atlas of nail disorders. Martin Dunitz, London Cork M 1997 The importance of the skin barrier function. Journal of Dermatological Treatment 8: S7-S13 Forslind B 1994 A new look at the skin barrier. A biophysical and mechanical model for barrier function. Journal of Applied Cosmetology 12: 63-72 Fortune D G, Main C J, O'Sullivan T M, Griffiths C E M 1997 Quality of life in patients with psoriasis: the contribution of clinical variables and psoriasis-specific stress. British Journal of Dermatology 137(5): 755-760 Freinkel R, Traczyck T 1985 Lipid compositions and acid hydrolase content of lamellar granules of the foetal rat epidermis. Journal of Investigative Dermatology 80: 441-448 Gawkrodger D J 1992 An illustrated colour text of dermatology. Churchill Livingstone, London Gillet du P 1973 Dorsal digital corns. Chiropodist July Glover M G 1990 Plantar warts. Foot and Ankle 11(3): 172-178 Harlow D, Poyner T, Findlay A, Dykes P 1998 High impairment of quality of life in adults with skin diseases in primary care. British Journal of Dermatology 139 (SuppI51): 15 Lawton S 2000 A quality of life for patients with skin disease. Skin Care Campaign Directory, London Lebbe C 1998 Human herpesvirus 8 as the infectious cause of Kaposi sarcoma: evidence and involvement of cofactors. Archives of Dermatology 134(6): 736-738 McKee P H 1996 Pathology of the skin with clinical correlations. Mosby-Wolfe, London Merriman L, Griffiths C, Tollafield D 1986 Plantar lesion patterns. Chiropodist 42: 145-148 Montagna W (ed) 1960 Advances in the biology of the skin: cutaneous innervation. Pergamon Press, Oxford Norlund J 1994 The pigmentary system: an expanded
perspective. Annals of Dermatology 6(2): 109-123 Office of Population Census and Surveys 1991-1992 Morbidity statistics from general practice. Fourth National Study 54: 22 O'Halloran N 1990 A biochemical investigation into the cholesterol content of seed corns. BSc dissertation, University of Brighton Pasyk K A, Thomas S V, Hassett C A, Cherry G W, Faller R 1989 Regional differences in the capillary density of the normal human dermis. Journal of Plastic and Reconstructive Surgery 83(6): 939-945 Ratnavel R C, Griffiths WAD 1997 The inherited palmoplantar keratodermas. British Journal of Dermatology 137: 485-490 Ryan T J 1995 Exchange and the mechanical properties of the skin: oncotic and hydrostatic forces control by blood supply and lymphatic drainage. Wound Repair and Regeneration 3: 258-264 Shelley W B, Rawnsley H M 1968 Painful feet due to herniation of fat. Journal of the American Medical Association 205: 308 Springett K P 1993 The influence of forces generated during gait on the clinical appearance and physical properties of skin callus. PhD thesis, University of Brighton Venning V 2000 The dermo-epidermal junction: an important structure in dermatology. Dermatology in Practice 8(1): 6-8 Whiting M F 1987 Survey of patients of large employer in SE England and Dept of Podiatry, University of Brighton. Unpublished, protected data Williams H C, Potter A, Strachan D 1991 The descriptive epidemiology of warts in school children. British Journal of Dermatology 128: 504-511 Zaias N 1980 The nail in health and disease. SP Medical, New York
FURTHER READING Baran R, Dawber R P R, Tosti A, Haneke E 1996 A text atlas of nail disorders. Martin Dunitz, London Dawber R P R, Bristow I R, Turner W A 2000 A text atlas of podiatric dermatology. Martin Dunitz, London Goldsmith LA 1991 Physiology, biochemistry and molecular biology of the skin. Oxford University Press, Oxford Harman R, Mathews CAN 1974 Painful piezogenic pedal papules. British Journal of Dermatology 90: 573
Lewis-Jones S 2000 The psychological impact of skin disease. Nursing Times 96(27): 2-4 (suppl) Leung A K C, Chan P Y H, Choi M C K 1999 Hyperhidrosis. International Journal of Dermatology 38: 561-567 Litt J Z, Pawlak G P 1997 Drug eruption reference manual. Parthenon Publishing, London Windsor A 2000 Sampling techniques. Nursing Times 96(27): 12-13 (suppl)
CHAPTER CONTENTS
Introduction 245 Why assess footwear?
246
The 'anatomy' of the shoe 246 The 'anatomy' of sports shoes 248
Footwear assessment L. Merriman *
Shoe construction 248 Lasts 248 Measurement 249 Methods of construction 250 Materials used in construction 252 Allergy to shoe components 253 Style 253 Suitable shoe styles 253 Unsuitable styles of footwear
255
Assessment of footwear 255 History taking 256 Assessment of shoe fit 256 Wear marks 261 Suitability 264 Everyday shoes 264 Hosiery 264 Summary
265
INTRODUCTION Assessment of footwear and hosiery is important as many foot health problems are associated with the foot coverings. The majority of women experience foot pain associated with wearing shoes (Frey 1995, Frey et al 1992). Footwear assessment may also be used for forensic purposes (McCourt 2000). Additionally, examination of the footwear can confirm a diagnosis or occasionally suggest a pathology which might not otherwise have been considered. Effective footwear assessment depends upon the ability to differentiate a suitable from an unsuitable shoe. To do this it is necessary to understand the function of the different parts of a shoe and the properties of the materials used in their construction. This chapter therefore begins with a section about footwear before the methods of assessment are described in detail. Well-fitting shoes are an essential part of the treatment of foot problems and the ability to assess fit is therefore an important tool. Several methods of measuring fit are described, together with some simple observations. The ability to read the pattern of wear on a shoe is a skill that can be used to assess how the foot functions within the shoe. Some of the common patterns are described. It is hoped that this chapter will stimulate the reader to observe footwear and understand its significance. "Linda Merriman wishes to acknowledge the work of Janet Hughes. This chapter is largely based on her work in the previous edition.
246
SYSTEMS EXAMINATION
Why assess footwear? Assessment of footwear is essential in the investigation of foot problems for many reasons. Perhaps the most important of these is that shoes give valuable information about how the foot functions during gait. It complements the assessment of the locomotor system (Ch, 8), much of which relies on barefoot observations, by assessing the way the foot functions during daily activity, i.e. wearing shoes. Examination of the wear and crease marks of footwear can be an aid to diagnosis as well as helping to complete the global picture. Another reason for the importance of footwear assessment is that unsuitable footwear can affect the efficacy of treatment or help to prolong a condition which might be alleviated by suitable shoes. In some instances shoes are the cause of the problem and effective treatment will consist simply of suggesting alternative shoes. Footwear is often neglected by practitioners and its assessment has not always been given the attention it deserves. This type of assessment is more of an art than a science and relies heavily on the experience of the observer. Gaining this experience is complicated by the enormous range of footwear that is available and the many different methods of construction. Observations of shod and unshod populations in the literature demonstrate that the unshod populations have fewer foot deformities than those who wear shoes. Research has also shown that when members of an unshod population start to wear shoes the incidence of foot problems increases. There is no experimental evidence showing that footwear is the cause but it is clearly implicated. Simple observation reveals that some feet survive even the most unsuitable footwear. The feet that survive unscathed are probably those with good bone structure and foot function. However, it can be assumed that for some feet inappropriate shoes will certainly cause deformity. Patients with foot deformity often report similar symptoms in relatives but note that they were not present as children. The shoes most likely to cause problems are those which do not fit well or are in some way
unsuitable. Well-fitting, suitable shoes should always be encouraged. While the basic function of footwear is protection both from hard and rough surfaces and from the cold, the appearance is often more important to the wearer. Patients exhibit strong resistance to change where their footwear is concerned. Many patients, particularly female, choose to ignore advice regarding sensible footwear, believing that what they consider to be an elegant appearance is more important than foot comfort. It is the authors' experience that patients are more receptive to footwear advice if the reasons for changing from highheeled court shoes to lace-ups can be explained. They are also more likely to believe that their shoes are too small when this is demonstrated by a few simple tests. It is important, however, not to be too dogmatic regarding patients' shoes. Advice is more likely to be accepted if it is made clear that smart shoes can still be worn for special occasions.
THE 'ANATOMY' OF THE SHOE Figure IO.IA shows the parts that make up an average lace-up shoe. The components can be grouped into those that make up the upper and those which form the sole. They are described individually below. Additionally there are areas which need reinforcement. These are highlighted in Figure IO.IB and described under the area they reinforce. Vamp. The upper is made of two main sections which are together moulded into the shape of the top of the shoe. The front section, which covers the forefoot and toes, is called the vamp. In some shoes the vamp is made of more than one piece, creating a decorative pattern; however, seams other than those joining the main sections are not recommended as they limit stretch ability and may rub bony prominences. The vamp is usually reinforced anteriorly by the toe puff, which maintains the shape of this section and protects the toes. In safety shoes this area is reinforced with steel to protect the toes from crushing injury. This reinforcement can be the cause of toe problems if it does not fit well.
FOOTWEAR ASSESSMENT
A
Insole
247
B
Tongue Topline
Eyelets --,...--,...--f--~/ (Oxford lacing) Throat line
-+---,ll---
Stiffener
Quarter
Heel --Toppiece
,/n_-
----,1-----''''
-#1'--- Vamp
<----7/<------ Shank
/H--Welt _ _ Toe cap
_~~:o.......
'<:::::::::::::::;::;;::::::<::::::.------ Outsole
" " ' - - - - - Toe puff
c
Figure 10.1 A. The 'anatomy' of a lace-up shoe, showing the parts of an Oxford-style laced shoe a shoe C. Alternative (Gibson) style of lacing.
Quarter. The sides and back of the shoe upper
are termed the quarters and their top edge forms the topline of the shoe. The medial and lateral sections often join in a seam at the centre of the heel. In lace-up shoes the eyelets for the laces form the anterior part of this section, whereas the tongue is attached to the vamp (Oxford style) or forms part of the vamp (Gibson style, Fig. IO.le). The inside of the quarter is usually reinforced around the heel by the stiffener. This helps to stabilise the hindfoot in the shoe. In some children's shoes and some athletic footwear the stiffener is extended on the medial side to help resist pronation. Toecap. The upper may have a toecap stitched over or replacing the front of the vamp. It is made into a decorative feature in some men's shoes, for example brogues.
B. The reinforcing within
Linings. Linings (not illustrated) are included in the quarters and vamps of some shoes to increase the comfort and durability. The lining for the bottom of the shoe is called the insock. It may cover the entire length of the shoe, threequarters or just the heel section. Throat. The throat is formed by the seam joining the vamp to the quarter. Its position depends on the style of the shoe. A lower throat line, i.e. a shorter vamp and longer quarters, will give a wider Ilower opening. This seam will not stretch and therefore dictates the maximum width of foot for which the shoe can be used. Insole. The insole is the flat inside of the shoe which covers the join between the upper and the sole in most methods of construction. Outsole. The outsole or sole is the undersurface of the shoe.
248
SYSTEMS EXAMINATION
Shank. The shank reinforces the waist of the shoe to prevent it from collapsing or distorting in wear. Shanks may not be needed in shoes with very low heels or in shoes where the sole forms a continuous wedge. Heel. The part of the shoe under the heel of the foot, also called the heel, raises the rear of the shoe above ground level. A shoe without a heel or a midsole wedge may be completely flat or have the heel section lower than the forefoot, in which case it is called a negative heel. The outer covering on the surface of the heel, which can be replaced when worn, is called the top piece. Welt. The welt is a strip of material, usually leather, used to join the upper to the sole in Goodyear-welted construction.
The 'anatomy' of sports shoes Since trainers replaced plimsolls sports footwear design has developed considerably, bringing new construction methods and terminology to the footwear industry. The functions of sports shoes are different to those of ordinary shoes as, for example, they may be required to absorb shock or provide some medial to lateral stability. The parts of a sports shoe are shown in Figure 10.2 and the terms illustrated are described below. MUdguard. Reinforcing round the outside of the rim of the toe is called the mudguard. Saddle. The saddle is reinforcing stitched to the outside of the shoe in the area of the arch.
---'
,-,-----,_.
Collar and heel tab. The topline of a sports shoe is often padded to form the collar. This may be shaped up around the back of the tendo Achilles to form a heel tab. Heel tabs were designed to protect the tendo Achilles but sometimes rub sensitive feet and may therefore need to be removed. Hindfoot stabiliser. One of the elements that may be incorporated into a sports shoe to attempt to counter pronation is the hindfoot stabiliser, which consists of a plastic meniscus between the midsole and the stiffener.
SHOE CONSTRUCTION Lasts The last is the mould on which most shoes are made and its shape and dimensions will dictate the fit and to some extent the durability of the shoe made on it. It is usually hinged around the instep to allow it to be removed from the shoe when construction is completed. Last design and manufacture are skilled occupations involving the use of many measurements, some of which are shown in Figure 10.3. Most of these are volume measurements rather than the traditional length and width measurements associated with shoe fit. The measurements of the last need to be different from the measurements of the foot to allow for movement in walking and the tightness of fit required by the wearer. It is these factors
Heel tab
Collar
Hind foot stabiliser
MUdguard
Midsole
Saddle Figure 10.2
The parts of a sports shoe.
Outsole
FOOTWEAR ASSESSMENT
Back curve
;
Heel height _---l~
+_--=:::.l!-_==----'-T""oe"-,spring
Waist curve Figure 10.3 Some of the measurements used in last design. 1 = throat opening; 2 = heel girth; 3 = length; 4 = heel to ball length; 5 = instep girth; 6 = waist girth; 7 = ball girth (joint).
which make it difficult to convert a plaster cast of a foot into a last without considerable modification. Other dimensions are dictated by fashion features and current style. A last for a high-heeled shoe, for example, will need to be much shorter than the foot for which it is being designed to compensate for the shortened equinus position in which the foot is held. Another example is the last for a court shoe, which differs from the last for an equivalent lace-up shoe by having an overly curved heel and a shallow toe puff in order to help the shoe stay on the foot. Some features built into the last may affect the fit and are therefore described below. Recede. The recede is the part of the last that projects beyond the tip of the toes and forms the rounded contour of the front of the shoe. A tapering recede, found in some fashion shoes, increases the overall length of the shoe. In a poorly designed last the recede may encroach on to the toes, causing pressure on the tips of the toes in walking. Flare. In the past there used to be no difference between left and right shoes until it was discovered that shoes were more comfortable with a degree of inflare. Now most commercially available shoes are made on lasts with some inflare. Occasionally, the flare of the foot does not match that of the shoe, causing characteristic wear marks on the inside of the shoe and pressure lesions on the foot. Heel to ball length. This dimension dictates the position of the hinge and the widest part of the shoe. It is essential that this corresponds to
249
the widest part of the foot, the metatarsophalangeal joint. Toe spring. Toe spring is incorporated into a last to compensate for the stiffness of footwear and is essential for the toe-off stage of gait. The more rigid the soling material, the greater the toe spring needed. Ball tread. This is the width across the sale under the ball of the foot and it should correspond to the width of the foot at this point. In some ladies' fashion shoes this width is decreased and compensated for with extra girth in order to give the appearance of a thinner, more elegant foot (Fig. 10.4); thus, the shoes will be narrower and deeper than the foot they are designed to fit and when worn the upper will overlap the sole.
Men's shoe f - + - - Women's shoe
Ball tread Figure 10.4 The different relationship of ball width to ball tread seen in women's and men's shoes. These shoes have identical width fittings.
Measurement The last is designed in a single size and then a set is made in the range of sizes and widths in which the shoes are to be manufactured. Marked sizes will vary slightly from one manufacturer to another. Length
Shoes are marked according to one of three different length sizing systems depending on where the shoes were made. Figure 10.5 gives a rough conversion table between the three major systems: United Kingdom, American and Paris Point (Continental). The UK scale starts at 0 for a
250
SYSTEMS EXAMINATION
A
o
B
C
11 ~
16 17
1
-
-
12 -
t-
2
-
'-
13 -
18 19
f-
3
-
f-
'-
14 -
4
-
21
-
15 -
22
5
::.-
;-
-
20
23
f-
6
-
Fittings
f-
7
-
Several standard width fittings are available in the UK size system to accommodate differences in three-dimensional girth. For ladies A is the narrowest and G the widest, for children the range is from A to H and for men it is from 1 to 8. The girth increase between fittings is normally 6.5 mm. Many lines are only made in one size and this is usually ladies' D or men's 4. The girth around the ball of the foot increases by 5 mm for whole sizes up to children's size 10 and 6.5mm for whole sizes above this. In the American system, the equivalent to the letter system is two more: e.g. AAA is equivalent to the UK A. There is no equivalent Continental width-fitting system and in general the shoes are narrower than in the UK.
=-
16 -
24
-
17 -
25
t-
8
-
-
18 -
26 27
c-
9
-
-
19 ...:;
28
f-
10
-
29
f-
11
-
12
-
t--
13
-
15
==
20 ~=
-
21
~
30 31 32
22 -
33
I-
1
-
25
'- 23 -
34
I-
2
-
35
I-
3
45
36 37
f-
4
38
I-
5
-
65
I-
6
-
75
7
-
85
r--
8
-
95
-
=
~
24 ~
'-
25
=- 26
~ ::=
=
~
35
39 40
55
'-
::: 27 --=
-
28 -
42
~ ::= '=
29 -
43
I-
9
-
105
44 45
t--
10
-
115
~ 30 -
-
125
=-
11
46 12
-
135
41
== '=
==
31 -
47
=- 32 -
foot measuring about 102 mm and has 8.4 mm between whole sizes and 4.2 mm between half sizes. After size 13 the scale restarts at size 1 for adult footwear. American shoes are approximately half a size larger than their UK equivalent for all except women's shoes which are one and a half sizes bigger. Paris Point begins at size 0 and increases by 6.5 mm between each size.
48
13
Methods of construction Shoes were traditionally made by moulding leather on to a wooden last. Modern technology has brought many new materials to shoe manufacture and has, to some extent, mechanised the construction, but it remains a fairly labour-intensive industry. The first stage in the construction of most shoes is to attach the insole to the undersurface of the last. The remaining construction is split into two main operations: lasting, when the upper sections are shaped to the last and attached to the insole; and bottoming, when the sole is attached to the upper. There are five main methods of bottoming and the one chosen will influence the price, quality and performance of the final product. Stuck-on (cement)
Figure 10.5 Comparison of measurements of shoe length A. Centimetres B. Paris Point C. English sizing system D. American women's sizes.
As the name implies, this type of construction involves sticking the sole to the upper (Fig. 1O.6A).
FOOTWEAR ASSESSMENT 251
A
C
Upper Welt
-l~:~~~.~=~r- Upper Outsole Midsole Insole
B
D
Upper--...,r/
Upper
Chainstitch inseam Filler Insole Lock stitch Outsole outseam
Outsole
Insole
Upper _ _Ill
Stitching Figure 10.6 Common methods of shoe construction stitched method.
Sole
Insole
A. Cement
This method is commonly used for both men's and women's footwear as it produces a lightweight and flexible shoe. Goodyear welt
The edge of the sole in a Goodyear-welted shoe is made of two sections. The top section, called the welt, is stitched to the upper and insole rib at the point where it curves under the last (Fig. 10.6B). The outsole is then sewn to the welt around the edge. This creates heavier, less flexible footwear and is used for high-quality dress and town shoes.
B. Goodyear C. Stitchdown
D. Moulded
E. Strobel-
Stitchdown
The upper is turned out at the edge of the last instead of being curved under it and attached to a runner (insole) (Fig. 10.6C). The sole is then stitched to the upper and runner. This is a cheaper method of construction. While not as strong as some constructions it produces a lightweight, flexible sole. It is used for children's footwear and some casual shoes. Moccasins
In this method the upper is not made in sections and lasted as previously described. A single
252
SYSTEMS EXAMINATION
larger section forms the insole, vamp and quarters, by being moulded upwards from the undersurface of the last. An apron is then stitched to the gathered edges of the vamp and the sole is stitched to the base of the shoe. This method is used for flexible fashion footwear. Moulded methods
In these methods the lasted upper is placed in a mould and the sole formed around it by injecting liquid synthetic soling material (Fig. 10.60). Alternatively, the sole may be vulcanised by converting uncured rubber into a stable compound by heat and pressure. These methods combine the upper permanently into the sole and such shoes cannot therefore be repaired easily. Moulded methods can be used to make most types of footwear. Force lasting
There are many variations of this method but the main one, which is increasing in use, is the sewnin-sock or Strobel-stitched method (Fig. 10.6E). The upper is sewn directly to a sock by means of an overlocking machine (or Strobel stitcher). The upper is then pulled (force lasted) on to a last or moulding foot. Unit soles with raised walls or moulded soles are attached to completely cover the seam. This is a modern method which has evolved from the construction of sports shoes but is increasingly used for casual shoes.
Materials used in construction
giving a smooth contour to the inside of the shoe. It is important to remember that the permeability of leather is likely to be impaired by special coatings, e.g. patent leather. Synthetic upper materials
Some synthetic materials (the poromerics) are permeable and allow the shoe to 'breathe' but none have the permanent suppleness found in leather. Most are slightly elastic and will stretch to some extent during wear; however, they will return to their original shape when taken off. For this reason shoes made of these materials should fit well and will not be as versatile at fitting awkwardly shaped feet as leather. Some synthetic materials may form a single deep crease, which can rub on the foot, instead of the many small creases found in leather. This problem is likely to be more pronounced when the shoes are too big. Many synthetic materials can be produced cheaply and are used to manufacture reasonably priced shoes. Providing they fit well and perspiration is not allowed to build up inside, they can be completely satisfactory. Other upper materials
Woven fabrics such as cotton corduroy can be used to make soft uppers. These are classified as breathable fabrics even if made of synthetic fibres; however, they will usually only stretch in one direction. They can make comfortable footwear, but it is essential that these fit well and are well constructed with adequate reinforcement, particularly in the heel area.
Leather upper materials
The traditional material for shoe upper manufacture is leather and it still has advantages over synthetic materials. The first of these is its permeability. Permeable materials allow perspiration to escape from the foot, producing a drier environment, which is less conducive to fungal growth. The second advantage is that leather stretches with wear and will permanently mould to the shape of the foot. Additionally, leather forms many tiny creases where flexing occurs,
Lining materials
All the materials used for upper construction can also be used for linings; however, the combination of a leather upper with a full lining made of a non-breathable, non-stretch material will have all the disadvantages of the lining materials and none of the advantages of the leather. In practice full linings are rare, but when they are used it is preferable that they be made of thin leather or fabric. Many linings are made of synthetic mate-
FOOTWEAR ASSESSMENT
rial but are usually confined to the quarters and the insock, where the loss of permeability and stretchability is not a problem. Leather soling materials
The ideal soling material must be waterproof, durable and possess a coefficient of friction high enough to prevent slipping. As for upper construction, leather has been the traditional material for the construction of shoe soles but synthetic materials are much more versatile than leather which, besides being very expensive, has poor gripping qualities. Synthetic soling materials
The advantages that man-made soling materials have over leather are that they are more durable, have better resistance to water and have higher coefficients of friction and, therefore, better grip. They can be made of flat material and be stuck or sewn onto the upper like leather, or they can be made in a shaped mould which is either stuck on or moulded directly on to the upper. Extra grip properties can be incorporated in the form of a distinctive sole pattern with well-defined ridges or they can be moulded with cavities to reduce the weight of the sole. These cavities need to be covered with a rigid insole or can be filled with light foam to produce a more flexible sole. Synthetic soling materials have been the subject of a great deal of research, particularly relating to sports shoes, and this has led to new designs and construction methods being used in all types of footwear. For example, two or more materials of different densities can be incorporated into the sole, e.g. to give a hard-wearing outer surface and a softer, more flexible midsole for greater comfort. Many synthetic soling materials possess a degree of shock absorption. Patients can sometimes relieve metatarsalgia by changing from thin-soled shoes to shoes with thick soles with good shock-absorption properties.
253
flexibility. Shank flexibility can be tested for by pressing down on the inside of the shoe on a flat surface. A suitable shank would be completely rigid or give slightly, but a shank that is too flexible will yield under this pressure and would allow the shoe to twist when weightbearing.
Allergy to shoe components Some components used in shoe construction can cause allergic contact dermatitis. Substances which sometimes cause skin problems are listed below. Rubber. Rubber, used for some soles, can be present even in an all-leather shoe as it is a constituent of many adhesives. Chemicals. The chemicals used in the process which turns animal hide into leather (tanning) and dyes used to colour it can leach out of the leather when the foot sweats. Other features. Materials such as nickel, used in eyelets and shanks, or the fungicides used to protect the leather, can also produce skin irritation. Diagnosis of these conditions can be made from the localised area affected by the eruption. Treatment involves use of footwear constructed without the causative component. Fortunately these conditions are rare. Help to identify suitable footwear can be obtained in the UK from organisations such as the Disabled Living Foundation and the Shoe and Allied Trades Research Association.
STYLE Figure 10.7 shows the seven basic shoe styles: lace-up, moccasin, court, sandal, boot, mule and clog. All shoes are variations on these themes. The history of footwear shows that styles reinvent themselves. Shoe styles tend to reflect contemporaneous expectations of society (Lawlor 1996).
Shank
Suitable shoe styles
The shank can be made of steel, wood or synthetic ~rial and will usually retain a slight degree of
Only the styles on the left of the illustration - the lace-up, sandal, boot and moccasin styles - fit
254
SYSTEMS EXAMINATION
Figure 10.7
The seven basic shoe styles
A. Lace-up
B. Moccasin
the definition of a sensible shoe, which must have a mechanism for holding the foot back in the heel of the shoe. Without this fixation the foot is allowed to slip forward into the toe space causing friction on the sole and trauma to the toes. Thus, there are two really important parts of an ideal shoe: a band around the instep and corresponding pressure at the heel. These parts, shown in Figure 10.8, should be firm and fit well. The band around the instep prevents the foot from sliding forward. This needs to be well up the instep to be effective. This is counterbalanced by pressure behind the heel to prevent the foot from sliding back. Support is often listed as being essential in a good shoe, but a normal foot does not need to be supported to function correctly or barefoot walking would be impossible. A good shoe should be firm enough to support itself and provide a solid base from which to push off. Recommending footwear is complicated by the constant changes to styles and models marketed by different manufacturers and the different uses for which shoes
C. Court
D. Sandal
E. Boot
F. Clog
G. Mule.
are designed. It is better, therefore, to recommend features to be found in a suitable shoe with an
Parts of the shoe that must be firm to prevent the foot from sliding back
Parts of the shoe that must fit snugly to prevent the foot from sliding forward
Figure 10.8 The parts of a shoe needing to fit well to prevent forward or backward movement of the foot.
FOOTWEAR ASSESSMENT
Table 10.1
Points to look for in an ideal shoe
• Laces with at least three eyelets Low, wide heel for good stability Good width at the front of the shoe to prevent cramping the toes • Deep, reinforced toe box • Firm stiffening round the heel • Curved back for close fit around the heel • Shaped topline, high enough up the instep for adequate fixation
255
but high heels became associated with fashion and style as early as the 16th century. High heels, defined as those that place the foot in more than slight equinus, are not suitable for everyday wear. In addition to the fact that they are nearly always slip-oris, they alter the normal biomechanics of the lower limb in walking. Habitual wear leads to permanent shortening of the calf muscles, barefoot walking is made uncomfortable and in severe cases the heels may not be able to touch the ground.
• Strong leather upper Hard-wearing synthetic sole Good fit • Good condition
explanation of why they are important. To assist this task a list of points to look for in a suitable shoe is included in Table 10.1.
Unsuitable styles of footwear Mules, clogs and court shoes, the styles on the right of Figure 10.7, are unsuitable for regular wear as they have no means of securing the foot. The only way that mules stay on is by being 'gripped' by the toes. This can lead to toe deformity. Slip-on shoes, especially court shoes, are bought too short and inevitably cramp the toes as the only way that they can stay on the foot is by wedging the foot between the curved back of the heel and the toe puff. When tried on in the correct size the foot slips forward into the toe space and the heel lifts out of the shoe on walking, giving the impression that it is too big. Clogs or slip-on shoes that extend right up the instep will limit forward movement to some extent. A properly fitting lace-up is always preferable (Fig. 10.8). In most shoes, even 'flat' ones, the heel is raised slightly above the level of the ground, so that the foot is in slight equinus. Even a modest height of heel will tend to throw the weight of the foot forward into the toe section unless it is restricted by an adequate fastening. It is therefore even more important for a high-heeled shoe to have a secure fastening. Raised heels are said to have developed as a protection from dirty streets
ASSESSMENT OF FOOTWEAR The assessment of footwear should not be seen as a separate entity to be completed after other aspects of the examination but should be integrated into the global assessment. For example, observation of patients walking in their shoes can often be achieved as they enter the clinic and there are some checks of fit which should be done before the shoes are removed. This will ensure that the number of times the shoes need to be removed and replaced is kept to a minimum. Table 10.2 lists the tests that should be included in a simple footwear assessment and Table 10.2 The parts of a simple footwear assessment and the stages at which they can be completed within the global assessment
Stage of assessment
Test
Brief description
In shoes Walking
Observe gait
Standing
Observe stance Check length Check heel to ball length Check width Check depth
Palpate end of longest toe Locate MTPJs in shoe Pinch upper over metatarsal heads Palpate toes during flexion
Barefoot Walking
Observe gait
Sitting
History Assess suitability of shoes Check wear marks Examine inside of shoe
Standing
Observe stance Note longest toe
256
SYSTEMS EXAMINATION
the stage at which each should be completed. They are described in full below. Performing these checks routinely, as part of a set sequence, will help to ensure that assessment of footwear is completed without undue effort. It should be remembered that hands should be washed between examination of the footwear and the foot. Patients attending for their first appointment should have been warned to bring a selection of their shoes, as new or 'best' shoes may not demonstrate the habitual wear pattern found in the shoes worn every day. There may therefore be several pairs of shoes to examine.
have a major influence on the style of shoes women are willing to purchase. Habits
Details of how often shoes are changed and whether long periods are spent wearing slippers or sports shoes can also be important. For example, a lady is unlikely to benefit from having a pair of suitable shoes to go out in once a week when she spends the rest of the week at home in slippers. Acquisition of footwear
History taking Background information about the patient's general footwear and purchasing habits is an essential part of the assessment of footwear. Financial circumstances
Before suggesting appropriate footwear, it is important to ascertain the financial circumstances of the patient, as this will influence her ability to follow the advice given. Women tend to spend less per item of footwear than men but they change their footwear more frequently; hence, in total, they spend more on footwear than men (British Footwear Association 1998). Wardrobe
Questions regarding the number of shoes owned and the number regularly worn may seem irrelevant but can add helpful information. This line of questioning may uncover that special shoes are worn at work and, therefore, need examination in preference to shoes worn only occasionally. There are specialist reinforced shoes for work in dangerous environments, smart shoes may be needed for office work or special shoes may be required for a specific sporting activity. Advertising and the media influence women's attitudes towards purchasing shoes (Reardon 1999). It is, therefore, important that the practitioner is familiar with current styles within 'the high street' as these could
Information about when, where and how often patients buy their shoes can be useful: e.g. do they have their feet measured or visit a selfservice shop? Whereas 40% of parents start off having their children's feet measured, by the age of 11 years only 15% of children have their feet measured (Stevens 1995). Independence
No assessment of footwear would be complete without noting the patient's ability to put on and take off her shoes or to do up and undo the fixation. Many adaptations to footwear and aids to assist independence are available and may form a valuable part of treatment. Sources of information are included in Further Reading.
Assessment of shoe fit Shoe fit is always a compromise as the shape of the foot is changing continually due to many different factors, some of which affect length and some girth. The biggest factor affecting length is weightbearing and measurements of length should, therefore, never be made when the patient is sitting. Girth is affected by body weight but is also highly sensitive to both temperature and swelling. There is thus a tendency for feet to be smaller in the morning than the evening. Measurements taken during the middle of the day will give the most representative results.
FOOTWEAR ASSESSMENT
Assessment of shoe fit is not an exact science: often observation and common sense are all that is required to decide whether shoes fit correctly. Sometimes a method of measuring fit is useful to demonstrate to patients that their shoes are inadequate. A well-fitting shoe should fit snugly around the heel and the arch and allow free movement of the toes. This section includes a comprehensive list of tests for different aspects of fit. It is not intended that all the tests described should be included in each assessment. They are listed partly to demonstrate the range of potential tests, but also to allow selection of an appropriate test to suit the problems experienced by the patient. In most cases the simplest test described will be adequate but, occasionally, when more accuracy is required, the more complicated measurements can be useful. The style of the shoe will to some extent dictate fit: e.g. a court or slip-on shoe is likely to be too small in length, width and depth. Additionally, the style of the front of the shoe can have a direct bearing on the fit in this region. Demonstration of poor fit by some of the tests described may help to convert the patient to sensible shoes. If shoes are really comfortable they are probably a good fit. Strangely, comfort is not as important a factor as might be expected when shoes are being purchased. Colour, style and heel height may compete equally. People, particularly women, seem to be tolerant of minor foot discomfort and it is necessary to explain that illfitting footwear may damage feet and that comfort should be paramount when choice of footwear is concerned.
257
• With the patient standing in her shoes, palpate the end of the longest toe through the toe puff. This may not be possible if the toe puff is reinforced. • Sprinkle a little talcum powder into the shoe and ask the patient to walk a few paces. When the shoes are removed an outline of the toes can be seen printed in the powder on the insole from which the gap can be assessed. It may be difficult to see the result of this test in footwear which extends high up the instep (high-waisted). • Cut a thin strip of card the length of the foot and slide this into the shoe until it touches the tip. This should reveal a gap of about 12 mm between the inside of the heel and the end of the strip of card (Fig. 10.9). This method can be influenced by the shape of the toe puff and is therefore most effective in round-toed shoes. To minimise the error, keep the width of the card narrow and do not slide it right to the end of very pointed-toed shoes. Shoes that are too short will mould the toes into the shape of the front of the shoe; shoes that are pointed are likely to cause pressure lesions on the toes.
\
o
,
Length
Correctly-fitting shoes should have a gap between the longest toe and the front of the shoe to allow for elongation of the foot, which takes place when walking. This gap should ideally be about 12 mm. Shoes that are too short will be recognisable, as the upper will tend to bulge at heel and toe. There are a number of simple tests with which this observation can be confirmed. They are not all suitable for all types of shoes.
, I
i
,,
"
I I
I I I
©
r~
--6
~
:<~~«{j(f>;a'. .
Gap equivalent to toe space Figure 10.9
A method of testing a shoe for correct length.
258
SYSTEMS EXAMINATION
Length of children's shoes. Children's shoes need a little more toe space than adults to allow for growth. A gap of 20 mm between the longest toe and the front of the shoe should be present in new shoes, allowing 8-9 mm for growth before new shoes are needed. If a child's shoe is worn out it is likely that it is too small, as it is usual for young feet to outgrow the shoe before it is worn out. It is also important to check for sock fit with growing feet as these too can be rapidly outgrown. Hosiery that is too small can cause as much damage as shoes that are too short.
Heel to ball length
Correctly-fitting heel to ball length will ensure that the hinge of the shoe is correctly aligned with the ball of the foot, and that the widest part of the foot is in the widest part of the shoe. It varies according to the design of the last. Average heel to ball length will be adequate for average feet, and will only need to be assessed if the toes are unusually short or long in relation to the rest of the foot. Heel to ball length will be incorrect if too much room for growth is allowed in children's shoes, when odd-sized feet are not fitted with different-sized shoes or when extra long shoes are bought to fit wide feet. This important measurement should only be assessed once the length of the shoes has been checked and found to be correct. Two techniques for measuring heel to ball length - one
simple and one more accurate - are described below: • With the patient standing in her shoes, feel for the metatarsophalangeal joint. If the bulge of the joint is level with the bulge of the shoe, this measurement is correct. • Measure the distance from the patient's heel to both the first and fifth metatarsal heads. Flex the ball of the shoe and measure the distance from the heel to the point at which the shoe bends both medially and laterally. The medial and lateral measurements from the foot and the shoe should correspond. Shoes with a heel to ball length that is too long will put unnecessary pressure and strain on the metatarsophalangeal joints, particularly that of the hallux, as the foot will be trying to flex the shoe where it is still reinforced by the shank. If the heel to ball length is too short, it will cause fewer mechanical problems but will restrict toe room (Fig. 10.10). Width
Correct width is also important and should be sufficient to allow the toes to rest flat on the insole without being compressed. Very few fashion shoes are made in width fittings so fashion shoes are often bought either too narrow or a size longer than they should be, to benefit from the corresponding increase in width. In a
Figure 10.10 Illustration of two feet with identical length but different heel to ball length and the result of fitting them both in the same shoe.
FOOTWEAR ASSESSMENT
shoe of inadequate width the upper will overlap the sole. Width can be assessed in a patient's footwear as follows:
259
Sale of shoe - f - - -
• With the patient standing in her shoes grasp the upper level with the metatarsal heads and try to pinch the upper material between the finger and thumb. If the upper feels tense and stretched and cannot be pinched, the shoe is not wide enough. If wrinkles appear then the shoe may be too wide. An additional check on width can be made on shoes with a well-defined throat line. This line governs the maximum width of the shoe as the seam will not stretch. There should ideally be enough space under the throat line to accommodate the tip of a pencil. If this extra space is not available, the throat line can bite into the fleshy dorsal surface of the foot on walking. Shoes which are too narrow will cause pressure lesions on the first and fifth metatarsophalangeal joints and the interphalangeal joint of the fifth toe. In diabetic patients these pressure lesions can progress rapidly to ulcers. Depth
Correct depth is important to prevent pressure being exerted on the tops of the toes. Unlike length and width, there is no increase in depth with an increase in shoe size. The depth of a shoe depends on its last. The degree of recede (see Fig. 10.3) incorporated into the last design will also affect the finished depth in the front of the shoe. If the patient is wearing, or needs, an orthosis, or has a toe deformity, then the depth is likely to be a problem. Inadequate depth causes a bulging toe puff. It can be assessed as follows: • With the patient standing in shoes ask her to take a step forward and pause just before toeoff, while still weightbearing equally on both feet. Palpate the upper of the flexed foot above the fourtl;). and fifth toes. If the toes are cramped, then the J'epth in the toe puff is inadequate. Shoes which are too shallow will cause pressure lesions on the interphalangeal joints of the toes and can also affect nails.
Top piece of heel - - t - - -
Figure 10.11 The outlines of shoe and foot from an assessment of shoe flare. The medial and lateral measurements are not the same on the two outlines, indicating an inflared shoe but an outflared foot.
Other factors affecting fit Shoe flare. If there is an indication that the flare of the foot does not match that of the shoe, this can be assessed as follows (Fig. 10.11): draw round the standing foot and, on the outline produced, join the centre of the heel to the second toe. Draw an outline of the shoe and join from a point below the heel seam at the back of the shoe to a point bisecting the top piece of the heel. Extend the line forward to the tip of the sole. Measure the maximum width of the medial and lateral sections of both outlines, noting which section is the widest. The widest part should be the same in both, and will usually be the medial sections. Inside border shape. Another factor affecting fit is the shape of the front of the shoe and its impact on the inside border (Fig. 10.12). The longest point on the foot is usually the great or second toe, but in shoes, the longest part is traditionally in the centre. Toes can often be painlessly moulded into pointed toe shapes, but this is likely to cause pain and deformity in the long term. A straight inside border is particularly
260
SYSTEMS EXAMINATION
Figure 10.12 Shoes with a straight and a shaped inside border and the effect on toes.
important for patients in whom the longest part of the foot is the hallux or who have a tendency towards hallux valgus. A simple way to demonstrate to a patient that shoes are unsuitable is to ask her to stand on an outline of the shoe with the heels aligned. Any overlap of the toes over the edge of the outline indicates that the shoe is incorrectly shaped. Pointed toes are not necessarily unsuitable but the toe shape must start after the toes and the foot must be prevented from slipping forward into the space by a strap or laces. Fixation. The means by which the foot is secured within the shoe will also need to be checked. Not only should the shoe not be worn too loose or too tight but also some adjustment should always be possible either to tighten or loosen the shoe. In a lace-up this means that there should always be a gap between the rows of eyelets up the front of the shoe. The effectiveness of the fixation can be checked by the following test: with the patient standing with one foot in front of the other grasp the shoe upper and ask the patient to lean forward on to the forward foot. If forward movement can be detected within the shoe, the fixation is inadequate. It is likely to be ineffective if the laces do not come far enough up the instep (three or four eyelet holes will be needed to give adequate fixation and opening) or the patient uses elastic laces or leaves
the laces/buckle done up when taking the shoe on and off, making the shoe a slip-on. Function. Most of the aspects considered so far have been static observations. It must be remembered that the shoe is required to function during activity as well as rest. The patient should therefore be observed walking while wearing their shoes and barefoot and any differences between the two noted. If the gait is better barefoot than when shod, there is likely to be some inadequacy of the shoes. Some points to compare when walking in and out of footwear are listed in Table 10.3, together with some possible causes of differences. Additionally, there are some aspects of shoe fit which can also be assessed when walking: the heel should not lift out of the shoe at each step; the topline should not gape on flexion; and there should be no movement of the foot within the shoe. Fitting problems
Anatomical variations mean that some people will have more problems finding shoes that fit than others. An example of this is a combination of a narrow heel and a wide forefoot. A standard shoe bought wide enough for the forefoot will be too loose at the heel. Shoes made on combination lasts used to be available to fit such feet but the best solution is a visit to an experienced
Table 10.3 Points to be observed with the patient walking barefoot and in shoes; any differences between the two sets of observations should be noted
Observation
Possible causes of differences
Step length
High heels will tend to cause a shorter step length
Overall stability
This may be affected by sole area
Angle of heel
Wear on the inside of a shoe will increase a tendency to valgus in relation to the tibia
Heel strike
Some footwear can cause a flat-footed gait
Toe-off
Stiff footwear can limit flexion at the metatarsophalangeal joint; incorrect heel to ball length may have the same result
FOOTWEAR ASSESSMENT 261
shoe fitter who will know what is currently obtainable. Assessment of the fit of a patient's shoes should be carried out on both feet even if the presenting problem is unilateral. A person's feet are commonly not identical in size and a pair of shoes may fit neither foot adequately. Small differences in size can be managed by shoes which fit the larger foot and adaptation for the shoe of the smaller foot. Differences of two sizes or more will need odd-sized shoes, as the discrepancy in heel to ball length will be too great. A list of suppliers of odd-sized pairs can be found by consulting organisations such as the Disabled Living Foundation (DLF) in the United Kingdom. Some adaptations to help overcome the problem are illustrated in leaflets available from the DLF and the books suggested in Further Reading. If the assessment shows up any deficiency in fit and the patient is willing and able to buy new shoes, suggest a visit to a shoe shop with a trained shoe fitter and a good stock of different fittings and last styles. Having feet measured may be something many people associate only with buying children's shoes. It is equally important for adults to be measured, particularly those with problem feet. Even specialist shops may have difficulty fitting feet which are bigger, wider or narrower than average. If a patient is having difficulty finding suitable shoes then specialist organisations like the Disabled Living Foundation should be consulted for appropriate manufacturers or stockists.
insufficient wear where some wear should be expected. Examination of the wear patterns of shoes will also reveal information about foot function. Distortions of the uppers can indicate abnormal frontal plane motion during walking. The wear marks on the heel and sole will reflect the direction of the weightbearing pathway during the gait cycle. Normal wear is the result of a smooth transfer of load from the heel to the forefoot. Some gait analysis equipment (Ch. 12) displays a centre of pressure line and it is logical to assume that normal wear will occur along this path (Fig. 10.13). The degree as well as the pattern of wear must be assessed, as shoes which are worn out or in need of repair are unsuitable for regular wear. One check of the degree of wear is to place the shoe on a flat surface and gently touch the back, front and each side. The shoe should be stable and not rock when touched. If rocking is detected then the shoe will provide an unstable base for walking and standing. Checking stance shod and barefoot will confirm these observations. Wear on the sale If the foot is functioning properly and is in a wellfitting shoe the pressure on the sole of the shoe
Wear marks Assessment of the pattern of wear on the soles and the uppers of patients' footwear can help to confirm a diagnosis of foot pathology and may also highlight deformity elsewhere, e.g. genu valgum. The patterns are to some extent predictable, given that the shoes enclose the foot and will mould to its shape. Well-defined deformities give classic wear patterns. It is important to be able to recognise the wear expected from a normal foot in order to differentiate that which is abnormal. Abnormal wear presents not only as an unusual pattern but also as excessive or
Centre of
--+---- pressure line under foot Areas showing normal wear
Figure 10.13 the heel.
The 'normal' pattern of wear on the sale and
262
SYSTEMS EXAMINATION
should be even and no one part should wear out excessively. It is normal, however, for signs of wear to occur under the medial central forefoot (Fig. 10.13). It is also normal for there to be a slight curvature of the undersurface of the sole. An element of this is built into the shoe by incorporating toe spring into the last (see Fig. 10.3), and this is accentuated by normal toe-off in walking. Any variation of the above will represent abnormal sole wear. Some examples follow. When the slight curvature on the undersurface of the sole is not apparent, or is not symmetrical or exaggerated, abnormal toe function is indicated. This is often the case in patients with rheumatoid arthritis who may have reduced toe function and a short stride. Insufficient wear on the posterior part of the sole indicates a heel to ball length which is too short and, when combined with excessive wear, at the tip of the sole, means that the whole shoe is not long enough. Wear at the tip of the sole alone may indicate that the shoe has been made on a last designed without enough toe spring, but insufficient wear in this area denotes lack of push-off. Excessive wear to the sole of the shoe may indicate limited dorsiflexion if it is towards the front of the sole, and pes cavus when it is across the tread without
Figure 10.14
extending down the lateral border (Fig. 10.14). An everted forefoot will show excessive wear along the inner aspect and an inverted forefoot will be worn along the outer aspect. Wear marks indicating a circular contact of the sole with the ground are caused when the metatarsal area is being used as a pivot, e.g. any condition that makes use of the toes uncomfortable. Examination of the sole will also reveal any areas of abnormally high pressure, e.g. under a single metatarsal head. Wear on the heel
The normal wear on a heel (see Fig. 10.13) spreads along the posterolateral border of the heel. Wear is not central, as might be expected, for several reasons: the entire calcaneus lies towards the lateral side of the inside of the heel of the shoe; the weightbearing tubercle is lateral to the midline of the heel; and the calcaneum is inverted at heel contact. Excessive wear along the lateral margin of the heel may indicate an inverted hindfoot, but this pattern is also seen in genu varum. Similarly, excessive wear on the inner aspect of the heel may indicate a valgus or everted hindfoot, but is also seen in cases of genu valgum.
The pattern of wear seen in the shoe of a patient with pes cavus.
FOOTWEAR ASSESSMENT
263
Combined heel and sale wear
A combination of excessive wear on the heel and the ball area of the sole can be seen in pes cavus. Along the medial border of the heel and sole it indicates a valgus or everted foot, and on the outer aspect of the heel and the sole it indicates inversion. This pattern may also be seen in hallux rigidus and severe in-toeing. Wear on the outer side of the heel and the inner side of the sole may be caused by an out-toed gait (external rotation of the hip). Unusual combinations/patterns of wear may simply be the result of a painful area being offloaded; for example, a painful heel may result in insufficient heel wear and abnormal wear in the sole.
Figure 10.16 The shoe deformity caused by medial prominence of the talar head (black arrow) in pes planus.
Crease marks in the upper
Normal creasing of the upper due to flexing during walking is slightly oblique and follows the line of the metatarsophalangeal joints. An excessively oblique crease mark is the sign of hallux rigidus in which toe-off occurs on the lateral side of the foot to protect the painful or rigid hallux (Fig. 10.15). The absence of creases in worn shoes indicates absence of toe-off, i.e. a short stride and flat-footed gait. Deformation of the upper
Distortions of the shoe's upper are caused by the shoe conforming to common forefoot defor-
mities. Hallux valgus distorts the medial border, bunionette/tailor's bunion the lateral aspect and hammer and claw toes create bulges in the top of the toe puff. Additionally, the heel stiffener may be caused to bulge at the back by pump bumps, on the lateral side by a varus or inverted hindfoot, and on the medial side by a valgus or everted hindfoot. Individuals with flat feet may distort the medial border because of the prominence of the talar head (Fig. 10.16). Scuffed toes are seen when there is a foot-drop deformity, as the toes are in ground contact during the swing phase of gait.
B
A
Figure 10.15
Crease marks on the upper
A. Normal crease marks
B. Crease marks with hallux rigidus.
264
SYSTEMS EXAMINATION
Examination of the inside of the shoe
The assessment of wear should also include an examination of the inside of the shoe. The wear patterns inside are likely to mirror those found on the heel and sole. Additional features such as creases, seams or rough areas and even nails through the sole may be the cause of localised lesions. The insock will often display a print of the sole of the foot from which the areas taking greatest pressure can be observed. Other signs of wear
The shoes of patients with diabetes mellitus may show a characteristic white deposit, sometimes accompanied by deterioration along the inner sides. These signs of wear have been publicised by the Shoe and Allied Trades Research Association (SATRA) who found the white substance to be glucose and the deterioration due to contamination by urine.
Suitability Table 10.4 lists the points that should be noted in the examination of shoe suitability, together with Table 10.4
Points to note in examination of shoe suitability
Points
Good
Bad
Style of shoes
Lace-up, sandal, boot, moccasin
Court, mule, clog
Method of fixation
Lace, buckle and bar, velcro Flat Leather
Elastic, none
Heel height Upper material Sale material
High-heeled Synthetic
Everyday shoes The preceding checks of suitability, fit and wear will only be meaningful if they relate to the patients' everyday shoes. Even if the shoes assessed are representative they may be fairly new or have been recently repaired and there is a great deal of information to be gained from examining more than one pair of shoes. New patients should be routinely asked to bring several pairs of footwear for examination. There are other occasions when it might be helpful to see a selection of footwear, e.g. when assessing a patient for orthoses. Another reason for asking to see additional footwear is to overcome the possibility that the shoes, which apparently conform to the advice given, are being worn only for visits to the clinic.
Synthetic, leather
Condition
New, scuffed, worn
Worn out
Sale wear patterns
Normal
Abnormal
Upper crease pattern
Normal
Abnormal
Fit
Good Good Good Correct Good
Too small/long Too wide/narrow Too shallow/deep Too long/short Bad
Length Width Depth Heel to ball Flare
the most common observations, divided into good and less good aspects. Such a list could be used as a quick record of the examination by circling the appropriate shoe feature. The suitability/ unsuitability would then be shown by the column in which the circles had been made. A shoe which was originally suitable may become unsuitable through age. Some shoe components deteriorate over time, e.g. the insole, which may become cracked or hollowed. Additionally, feet change shape with age and fit may be compromised. A shoe may also be unsuitable if it is inappropriate for the conditions/situation in which it is worn. A common example of this is found in patients with rheumatoid arthritis who, because of the difficulty of finding footwear to fit, wear sandals all year round.
Construction
Welted, cemented, moccasin, moulded
Type
Dress, casual, sports, work
Hosiery Socks and stockings that are too small restrict the circulation to the foot and can do just as much damage to the toes as shoes that do not fit. Hosiery fit should therefore be checked at the same time as shoe fit and this is particularly important in children, where the foot is still growing. Socks and stockings may be outgrown, have shrunk with inappropriate washing or simply have been bought too small. The sizing of
FOOTWEAR ASSESSMENT
stretch socks can lead to confusion as the range of sizes printed on the label indicates the range from unstretched to full stretch. Socks will be more comfortable and cause fewer compression problems if the unstretched size corresponds to the shoe size. The materials used in the manufacture of hosiery can affect foot health. Socks made of natural fibres may be needed by patients with skin conditions such as eczema, but a mixture of natural fibres and synthetic substances is often an advantage, as the synthetic material can help to keep the foot dry. Natural fibres absorb moisture and remain damp. Synthetic fibres let the moisture pass through to an absorbent surface on the other side, for example a leather upper. This
265
process, known as wicking, keeps the foot dry but will not take place if shoes are made of, or lined with, synthetic material.
SUMMARY This chapter has described the factors which should be included in an assessment of footwear. The reader should now be able to judge the suitability of footwear and whether it is contributing to the foot problems experienced by the patient. The ability to use footwear assessment to both the advantage of the patient and the practitioner will come only with experience, but it is hoped that the importance of this often neglected aspect has been clearly demonstrated.
REFERENCES British Footwear Association 1998 Footwear facts and figures, 1998 edition. British Footwear Association, London Frey C 1995 Pain and deformity in women's feet ... are shoes the cause? Journal of Musculoskeletal Medicine 15: 35-38,43--46 Frey C, Thompson F, Smith J, Sanders M, Horstman H 1992 American Orthopaedic Foot and Ankle Society women's shoe survey. Foot and Ankle International 2: 78-81
Lawlor L 1996 Where will this shoe take you? A walk through the history of footwear. Walker & Company McCourt F 2000 A problem of attribution in forensic podiatry. British Journal of Podiatry 13: 107-110 Reardon K 1999 Lowdown on the right shoe. The Times Weekend 13 March: 5 Stevens G 1995 Society news. Journal of Podiatric Medicine 50: 10
FURTHER READING Hughes J R (ed) 1982 Footwear and footcare for children. Disabled Living Foundation, London Hughes J R 1983 Footcare and footwear for adults. Disabled Living Foundation, London Hunt G C (ed) 1988 Physical therapy of the foot and ankle. Churchill Livingstone, New York
Sources of information Disabled Living Foundation (DLF), 380-384 Harrow Road, London W9 2HU Independent Footwear Retailers Association, PO Box 247, London W4 SEX Shoe and Allied Trades Research Association (SATRA), Rockingham Road, Kettering, Northants NN169JH
CHAPTER CONTENTS
Introduction
269
Generation of X-rays 269 The effects of radiation on tissue
270
Ordering an X-ray 270 Oorsiplantar view (OP) 271 Lateral view (weightbearing) 271 Anteroposterior ankle (AP ankle) 273 Axial view of sesamoids 274 Oorsiplantaroblique view 274 Basic radiological assessment Alignment 276 Bone density 282 Cartilage 285 Soft tissue 285
Other imaging modalities 296 Computed tomography (CT) 296 Magnetic resonance imaging (MRI) 296 Nuclear medicine - isotope scanning 298 Fluoroscopy 299 Ultrasound 299 300
1. Turbutt
275
Radiological assessment of specific pathologies 287 Infection 287 Osteoarthritis 287 Autoimmune disease 288 Osteochondrosis 289 Trauma 291 Foreign bodies 292 Neoplasia 292
Summary
Radiographic assessment
INTRODUCTION The role of the specialist in foot disorders is an expanding one. As the knowledge of foot pathology has increased so has the complexity of referred cases and treatment regimens. Many clinical diagnoses can only be confirmed by the use of one of the imaging modalities. This chapter is designed to give a workable base of information on the ordering and interpretation of X-rays of the foot, and other imaging techniques, together with relevant pathological detail. This knowledge is particularly important for those involved in surgical practice but has great relevance for all progressive practitioners in foot health. This chapter should be seen as a starting point for further reading and development in this fascinating and rewarding field. The interpretation of X-rays is complex and extremely skilled and it should be borne in mind that it is normal practice within the National Health Service, and good practice in the private sector, for all films taken to be reported by a radiologist. In the light of such a report one may add one's own specific skills and clinical findings to complete the diagnosis.
GENERATION OF X-RAYS X-rays are generated by the passage of a high voltage through a heated coiled tungsten wire (the cathode) in a toughened glass tube containing a vacuum, producing free electrons in a process known as thermionic emission. At the 269
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other end of the tube is the anode, consisting of a heavy metal disc, normally tungsten, embedded in a copper bar, which rotates to absorb heat. When a high potential difference is applied between the electrodes the electrons from the cathode stream at high velocity towards the anode (cathode rays) and bombard the tungsten target. If a positive nucleus of a target atom is bombarded by fast-moving free negativelycharged electrons from another source a repulsion and braking effect (the bremsstrahlung process) takes place. The electrons decelerate and emit energy in the form of radiation and if the energy levels are high enough the radiation is in the form of X-rays. The bombardment of atoms heavier than sodium, such as tungsten, by free electrons will produce a high energy wave of X-rays in the range 10- 7-10-10 em, as well as other charged particles known as alpha particles, beta particles and gamma rays. The resulting X-rays are focused as required by a light-beam diaphragm - lead shields, visually aligned on the patient with a beam of light. Radiation is able to penetrate dense objects for a certain distance, dependent upon both the density of the object and the power of the radiation beam. X-rays produced by low voltages, below 50 kV, will not penetrate tissue for any great distance and may be considered 'soft' X-rays. Those produced by higher voltages penetrate for increasing distances and are known as 'hard' X-rays. When an X-ray beam passes through tissues, such as the foot, and strikes a sensitive film emulsion, it produces a chemical change and forms a negative image of the tissues, which may be viewed once the film has been processed. The most dense tissue, i.e. bone, is shown as white and the less dense tissues are shown as increasing shades of grey and black. In practice it takes quite a large amount of X-radiation to alter the film: to reduce the patient dose, the film is normally placed in a cassette containing rare earth intensifying screens. These screens fluoresce when struck by relatively small amounts of radiation and it is the fluorescence that changes the film. This reduces the radiation dosage required by up to 90%, depending on the type of screen,
and is therefore far safer for the patient and operator. The SI unit of radiation absorbed dose is the gray (Cy).
The effects of radiation on tissue All ionising radiations are harmful to living tissue, and must be accorded the greatest respect. It is a firm principle that the advantage to the patient of having a radiographic examination should outweigh the associated radiation hazard. Effects of radiation may be somatic or genetic. Radiation suppresses the ability of cells to reproduce. The sensitivity to radiation is related to oxygen saturation of the cells. Neural tissue is the least sensitive, and blood cells and bone marrow are the most easily damaged, leading to anaemia and leukaemia in severe cases of overexposure. The thyroid gland and the lens of the eye are also vulnerable. The gonads are radiosensitive and temporary or permanent sterility, or even genetic mutations, can be caused by the excessive irradiation of the gonads of a person of reproductive age (Swallow et al 1986). However, the low level of dosage received in most properly conducted radiographic examinations, and in particular with the foot, means that there is absolutely minimal risk of any damage.
ORDERING AN X-RAY Any practitioner in the United Kingdom who wishes to clinically or physically direct Xvradiation must have core knowledge training as stipulated in the Ionising Radiation (Medical Exposure) Regulations 2000. The course, usually arranged by physicists, will make the practitioner aware of all the safety aspects and the code of practice relating to the direction of radiation. If the patient is referred by the practitioner to an Xray department the core knowledge training is not necessary as the radiologist is deemed to be clinically directing the examination. For an investigation to be of maximum use to the practitioner the reason for the referral, any relevant clinical history, the information sought, the views required and whether or not they
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should be taken weightbearing must be clearly specified to the radiographer and the radiologist. Wasted time, missed diagnoses and unnecessary radiation exposure can result from a poor request. One of the important questions on any X-ray request form relates to the recent menstrual history of any female patient of childbearing age. This is to protect any early fetus from potential radiation exposure. A female patient of childbearing age should be asked whether or not she might be pregnant. If she cannot be certain the form should be clearly marked accordingly. In fact radiographs of the foot, correctly taken by a radiographer, present no hazard to any fetus, as the dosage is low, the beam is not angled towards the abdomen and gonad protection can be used. It is therefore unlikely that a radiographer will refuse to X-ray the foot of a pregnant woman (National Radiological Protection Board). It .is important that at least two views of any portion of the anatomy are obtained. As an X-ray is a two-dimensional rendition of a threedimensional object, pathological changes cannot be properly assessed without more than one perspective. It should also be remembered that an X-ray image will inevitably have some enlargement and distortion of size compared to the actual structures. . In gene~al it may be said that weightbearing VIews, WIth the patient standing in normal angle and base of gait, are of most use to the practitioner. It is then legitimate for certain biomechanical features to be deduced as well as pathological features. Otherwise, such deductions are little more than guesswork. However, it should perhaps be noted at this point that the ordering of X-rays for routine biomechanical assessment is not good practice, involving radiation exposure which is generally considered to be unnecessary. Some of the most commonly requested views, and the reasons for taking them, are shown below. However, it should be borne in mind that there are many variations and other options in favour with various departments of radiology.
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Dorsiplantar view (DP) This is a general-purpose view, taken either weightbearing (WB) or non-weightbearing (NWB), which will show the majority of the foot ~rom the midtarsal area distally. The X-ray beam IS angled at 15° to the naviculocuboid joint as shown in Figure 11.1. Some departments will take both feet simultaneously, and the beam will be directed between the feet at the level of the first metatarsophalangeal joint. The neck of the talus, the distal edge of the calcaneum, the tarsus, metatarsus and digits will be clearly seen (Fig. 11.2). Normally the bodies of the talus and the calcaneum will be occluded by superimposition of the lower ends of the tibia and fibula.
Lateral view (weightbearing) This is taken with the beam at right angles to the foot, centred on the styloid process with the medial side of the foot close up against the cassette (Fig. 11.3). The entire lateral view of the foot should be visible (Fig. 11.4). This view will clearly show the tibial and fibular malleoli superimposed over the talus, as well as the calcaneum the subtalar joint, calcaneocuboid joint and talo~ navicular joint. The midtarsal complex will be partially obscured by the multiple superimpositions of the cuneiforms and metatarsocuneiform articulations, although the first metatarso-
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Figure 11.1
Positioning for dorsiplantar (DP) view.
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Figure 11.3
Positioning for lateral view.
.. Figure 11.2 Dorsiplantar view shows a mild hallux abductus deformity. Note also the bipartite medial sesamoid, and additional sesamoid under the second and fifth metatarsal heads.
Figure 11.4 Positioning for lateral view (weightbearing). A typical lateral view, giving a good outline of the talus, calcaneum and medial column. Compare with Figure 11.16.
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cuneiform joint should be well seen. The lesser metatarsals will be partially superimposed over each other, although the first metatarsal and hallux, and the structure of the first metatarsophalangeal joint, should be easily distinguishable.
Anteroposterior ankle (AP ankle) This is a view taken with the beam directed along the longitudinal axis of the foot towards the ankle (Fig. 11.5). It is particularly ordered when ankle injury is suspected. It will show virtually no detail of the forefoot, due to marked superimposition, but it is designed to clearly demarcate the trochlear surface of the talus and the articulations with the tibia and fibula (Fig. 11.6). The malleoli are very clearly seen. Avulsion fractures, which occur with inversion and eversion injuries, can usually be seen on this view.
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Figure 11.5 (AP ankle).
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Positioning for anteroposterior view of ankle
Figure 11.6 Anteroposterior view of ankle. This view clearly shows the lower ends of the tibia and fibula and outlines the trochlear surface of the talus. In this case there is a history of an old avulsion fracture of the fibular malleolus and nonunion of a small fragment at the apex.
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This view is sometimes taken as a non-weightbearing stress radiograph in which the foot is held in inversion or eversion and the amount of ligamentous damage is checked by assessing the degree of tilt of the talus available in the joint. This can naturally be a painful procedure and may require an anaesthetic.
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Axial view of sesamoids Although not commonly standard this view can be most helpful if degenerative change is suspected in the sesamoids under the first metatarsophalangeal joint. The beam is angled towards the sesamoids with the foot flexed at the metatarsophalangeal joints (Fig. 11.7). A special positioning platform may be used in some departments, but more usually the patient will be asked to retract the toes with the assistance of a loop of bandage. The view will show the ends of the metatarsals, and the sesamoidal relationship with the metatarsal will be clearly demarcated, along with any enlargement or disease (Fig. 11.8).
Dorsiplantar oblique view The oblique view is a non-weightbearing view which may be taken in several ways. The most
Figure 11.7
Positioning for axial view ofsesamoids.
common method is for the patient to sit and incline the foot at approximately 45° to the cassette, with the beam centred on the naviculocuboid joint perpendicular to the dorsum of the foot (Fig. 11.9). This view gives a distorted image of the midtarsal area, but is particularly useful for the open view given of the articular facets in the area (Fig. 11.10). Degenerative changes and pathology such as tarsal coalitions may be readily distinguished.
Figure 11.8 Axial view ofsesamoids. The sesamoids under the head ofthe first metatarsal are clearly seen, together with the intersesamoidal ridge. In addition, there is a sesamoid underlying the fifth metatarsal head.
RADIOGRAPHIC ASSESSMENT
Figure 11.9 oblique).
Positioning for dorsiplantar oblique view (OP
BASIC RADIOLOGICAL ASSESSMENT There is a vast amount of information that may be deduced from the careful study of an X-ray. Increased or decreased bone density, soft tissue abnormalities, age, degenerative change, trauma, metabolic disease, biomechanical abnormalities, foreign bodies and surgical interventions will all be reflected in the film. It takes much practice and knowledge to detect some of the subtler alterations in appearance. For this reason it can help to adopt a system of assessment in order to avoid missing important basic clues to a disorder. A system which has found favour amongst some is known as the ABCS of radiological assessment, where: A = Alignment and variations B = Bone density C = Cartilage S = Soft tissue.
Figure 11.10 Oorsiplantar oblique view. In this nonweightbearing view it is possible to see the articular facets of the midtarsal joint complex much more clearly than with a weightbearing OP view. Although distorted, it also gives a useful alternative view of the other joints.
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Alignment In order to make judgements about the biomechanical features of a particular foot as seen on X-ray it is important to decide how the picture was taken. One cannot assess with accuracy any osseous malalignment if the film was not taken weightbearing, and preferably in normal angle and base of gait. Since not many imaging departments actually take films in this way, a cautious approach should be adopted. However, one may certainly make some generalisations about the appearance of a 'normal' foot on weightbearing dorsiplantar and lateral views. It is sometimes useful to draw angles and reference points on acetate sheets overlying the films. Angles quoted below should be considered as broad guidelines only. In this section the commonly seen anatomical variations, in particular accessory sesamoids, will be discussed. Oorsiplantar view (OP)
Commencing at the rearfoot, first examine the relationship between the talus and the calcaneum (Fig. 11.11). Normally there will be considerable superimposition of the talus over the calcaneum, and there will be a small notch, the talocalcaneal notch, between the two at their distal edges. In a pronated foot, as the talus adducts and plantarflexes relative to the calcaneum, this notch will increase. In a supinated -foot the notch disappears and the superimposition becomes complete. Moving distally, look carefully at the talonavicular and calcaneocuboid articulations. In a pronated foot the head of the talus will move progressively out of alignment with the cupped surface of the navicular. In a severely pronated foot of long duration there may be a flattening and remodelling of the talar head on the medial side, with as little as 20% (normal 60-70%) of the articular cartilage surface remaining within the normal confines of the joint. There will be a progressive abduction of the cuboid, the navicular and the three cuneiforms as pronation increases. This lesser tarsus abduction angle may
Figure 11.11 Dorsiplantar view (weightbearing). A case of a moderate hallux abductovalgus deformity which exhibits mild pronation at the subtalar joint, as evidenced by adduction of the head of the talus and relative abduction of the lesser tarsus. There are increases in the metatarsus primus varus angle and the hallux abductus angle, and the hallux is laterally displaced and slightly rotated into valgus. There is a lateral displacement of the sesamoids into the intermetatarsal space.
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be measured against a bisection of the tarsus (Fig. 11.12). The shift of the talus and lesser tarsus are somewhat reversed in a supinated foot structure, although the talus clearly cannot move very far laterally and there is a denser superimposition of the bones. The articular surface of the navicular with the three cuneiforms should be clearly visible. It should be possible to see the outlines of the cuneiforms, but it can be difficult to see the facets of all the intercuneiform joints due to superimposition. In a case of osteoarthritic degeneration the joints of the whole lesser tarsus can become indistinct.
Figure 11.12 Biomechanical evaluation of a DP view. Diagram to show: lesser tarsus abduction angle (A), metatarsus adductus angle (B), metatarsus primus adductus angle (C) and hallux abductus angle (D).
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Further distally the metatarso cuneiform joints, the fifth metatarsocuboid joint and the intermetatarsal joints are visible, although superimposed. There is a notch present between the first and second metatarsal bases, the metatarsocuneiform split, greater in some cases than others. This may be related to the angle of the distal surface of the medial cuneiform. The base of the first metatarsal appears to have an additional transverse facet. This is in fact a superimposition of the plantar aspect of the metatarsal base, which is cup-shaped. The lesser four metatarsals are normally parallel and virtually straight, with the fifth metatarsal sometimes exhibiting a lateral bowing, depending on the exact angle of the X-ray beam. A longitudinal bisection may be drawn of the second metatarsal and compared to a bisection of the lesser tarsus. The resulting angle, the metatarsus adduction angle, can be of some value in determining whether or not the condition of metatarsus adductus exists (Fig. 11.12). Some authorities believe that a normal range would be 10-20°, with a higher figure indicating that the condition is present. There will be an increase of this angle in a supinated foot and greater superimposition of the metatarsal bases over each other. Of great importance is the relationship between the first metatarsal and the others. Construction of longitudinal bisections of the first and second metatarsals enables the metatarsus primus adducius angle to be measured (Fig. 11.12). Most authorities consider that the norm is 8-10°. Naturally, this angle increases dramatically in cases of metatarsus primus adductus, a component of a hallux abductovalgus deformity, and the intermetatarsal space widens. The first metatarsal sesamoids normally lie approximately 0.5 em proximal to the articular surface of the metatarsal head, approximately in the midline, and should appear as two smooth ovoid structures. They may be bipartite or multipartite. This does not necessarily indicate disease or injury, although sesamoids can fracture like any other bone. Since they underlie the metatarsal there is an increased depth of bone for
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the X-ray to penetrate. As a result they appear more dense than the rest of the metatarsal. In a case of developing hallux abductus, the sesamoids progressively move laterally, with the lateral sesamoid eventually ending up in the interspace between the first and second metatarsals, the medial sesamoid following closely behind. The sesamoidal position can be plotted against the metatarsal bisection if required. The drawing of arcs from the intersection of the metatarsal bisections allows the relative lengths of the first and second metatarsals to be assessed, the metatarsal protrusion distance (Fig. 11.13). This latter measurement is generally considered normal at ± 2 mm. In the ideal foot the hallux articulates completely with the metatarsal. If a bisection of the shaft is drawn and compared to the metatarsal bisection the hallux abduction angle can be measured (see Fig. 11.12). The hallux may normally deviate laterally by a small amount, compensating in effect for the normal metatarsus primus adductus angle. Less than 15° is generally considered acceptable. In hallux abductus this angle increases and the articulation becomes progressively less congruous until a partial lateral subluxation occurs, with only a relatively small
portion of the cartilaginous surfaces in apposition. The valgus rotation that occurs may be clearly seen in advanced cases, with the plantar condyles of the proximal phalanx becoming progressively more visible. The resultant degenerative changes will be discussed later. Deviation of the cartilaginous surface of the metatarsal can in some cases be identified and quantified by construction of the proximal articular set angle (PASA). This angle has relevance in the planning of surgical procedures for hallux abductovalgus (Fig. 11.14). A deviation in the shaft of the proximal phalanx of the hallux itself can be identified by drawing the distal articular set angle (DASA) (Fig. 11.15). This type of deformity is sometimes responsible for the abduction deformity sometimes seen in a hallux when the first metatarsophalangeal joint alignment is normal. Occasionally, a hallux will have an interphalangeal joint abduction deformity which can lead to the distal abduction deformity sometimes referred to as 'terminal valgus'. The alignment of the digits may vary. Even the most normal toes are not actually straight, but they should sit congruously on to the ends of the metatarsals. However, abduction, adduction, subluxation, dislocation and flexion deformities are
Xmm
Figure 11.13 Measurement of metatarsal protrusion distance. Bisections ofthe metatarsal shafts are extended proximally, and arcs are drawn to the articular surfaces. The distance between the two arcs is measured.
Proximal articular set angle (PASA). Aline representing the limits ofthe articular cartilage on the metatarsal head is compared to a perpendicular to the bisection ofthe metatarsal shaft.
Figure 11.14
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Lateral view
DASA
Figure 11.15 Distal articular set angle (DASA). A line representing the articular surface of the proximal phalanx is compared to a perpendicular to the bisection of the phalangeal shaft.
exceedingly common. The superimposition of sometimes very small phalanges can sometimes make it difficult to decide on the presence or absence of bony ankyloses or other pathologies.
A weightbearing lateral view will yield much useful information (Fig. 11.16). The malleoli of the tibia and fibula will be seen superimposed over the trochlear surface of the talus. The malleoli should be smooth in outline, as should the trochlear surface. The talus should be domed. Undue flattening or irregularity may be indicative of degenerative disease. The facets of the subtalar joint should be clearly demarcated and the sustentaculum tali and sinus tarsi readily apparent. The facets and the sinus tarsi become obscured in a pronated foot and more visible in a supinated one. The calcaneum is inclined to the supporting surface, and the calcaneal inclination angle can be easily measured (Fig. 11.17). The normal angle will vary according to the midtarsal joint axes of motion for any particular foot: 0-10° would be considered low, 11-20° medium and 21-30° high. However, the measured angle will vary
Figure 11.16 Lateral view (weightbearing). In this pronated foot the talus is displaced medially and plantarly, obscuring the facets of the subtalar joint. The cyma line has a marked anterior break, with the smooth curve being invisible, and a bisection of the talar neck would clearly fall below the level of the first metatarsal shaft. The calcaneal inclination angle is low. Compare this foot to that shown in Figure 11.4.
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Figure 11.17 Diagram of lateral view. Note the cyma line (A-B), declination of the talus (C) and calcaneal inclination angle (0).
according to whether or not the foot is abnormally pronated or supinated and clinical judgement is important. While looking at the calcaneum one should check for the presence of retrocalcaneal enlargement in the area of the Achilles tendon insertion (Haglund's deformity) or for spur formation on the distal plantar aspect, bearing in mind that many so-called spurs are completely asymptomatic. A bisection through the sloping body and neck of the talus will demonstrate the talar declination angle in relation to the supporting surface (Fig. 11.17). A continuation of this line will normally fall within the confines of the first metatarsal shaft. In a pronated foot the talar declination angle increases and the line falls below the first metatarsal. Conversely, it will rise above it in a supinated foot as the talus is relatively adducted and dorsiflexed. The talonavicular and calcaneocuboid joints together produce a superimposition on a lateral X-ray known as the cyma line (Fig. 11.17). These curved joints together form a reverse 'lazy 5' as an intact curve in a normal foot. In a pronated foot the '5' becomes broken as the talonavicular joint moves anterior and plantar to the calcaneocuboid joint, and once again the reverse occurs in a supinated foot. In a severely pronated foot the talus and navicular plantarflex and exert a downward and retrograde tilting force on the posterior aspect of the medial cuneiform, resulting in a naviculocuneiform fault. In such cases the intermediate
cuneiform, not normally visible, may be seen protruding above the medial cuneiform. Less commonly, a calcaneocuboid fault may be seen in a high-arched foot. In this situation the cuboid may become partially displaced under the anterior plantar process of the calcaneum. In a case of restricted subtalar joint motion it is worth carefully assessing the tarsus to eliminate the possibility of a tarsal coalition, although an oblique view is generally more help in this regard. In the midtarsal region there is considerable superimposition, and it can take some time to distinguish the metatarsal bases from the cuneiforms. Any degenerative changes in the midtarsal region can usually be seen outlined along the dorsal surfaces. The first and fifth metatarsals are normally easily outlined, with the others being partially superimposed. In a supinated foot one may more clearly see the second, third and fourth metatarsals. In a pronated foot the superimposition becomes more complete, and it may only be possible to clearly distinguish the first metatarsal. At first metatarsophalangeal joint level one may see the medial and sometimes the lateral sesamoids, appearing as two ovoid structures approximately 1.0 cm diameter that are more dense due to superimposition. Their position and outline, which should normally be smooth, should be ascertained. These sesamoids may be bipartite or multipartite and are as subject to degenerative change as any other osseous structure. Osteoarthritis will produce enlargement and irregularity in the sesamoids. The dorsal aspect of the metatarsophalangeal joint should be assessed for degeneration. The hallux should normally lie in line with the metatarsal, being neither dorsiflexed nor plantarflexed. Similarly, at the interphalangeal joint look for hyperextension, flexion or degeneration. The distal phalanx can be conveniently checked for distal tufting or exostosis formation. The lesser metatarsophalangeal joints are sometimes visible, and in particular it can be possible to pick out dorsal subluxation or dislocation.
RADIOGRAPHIC ASSESSMENT
Anatomical variation
There are many variations of anatomical form, such as the accessory ossicles, which occur frequently enough to be considered 'normal variants', and others which represent interesting hereditary and congenital malformations of varying degrees of severity. Accessory ossicles occur regularly in association with all the major bones in the foot (Figs 11.18 and 11.19). Most give no cause for concern, but a proportion give rise to symptoms, particularly following trauma or sporting activity, and should certainly be considered in a differential diagnosis.
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Os trigonum. This ossicle is a secondary epiphysis, found on the posterior aspect of the trochlear surface of the talus, which fails to fuse to the talus in about 8% of the population. It can give rise to symptoms when the foot is regularly plantarflexed, or subject to injury, as in footbaIlers and ballet dancers. Os tibiale externum. This ossicle lies under the insertion of tibialis posterior as it crosses the navicular, and is subject to problems following forced abduction or eversion injuries. Os peroneum. This ossicle lies under peroneus longus in the peroneal groove of the cuboid and is sometimes not noticed except on a lateral or oblique X-ray. Occasionally, it can be symptomatic, particularly in a supinated foot. Os vesalianum. This ossicle is a secondary epiphysis at the fifth metatarsal base and must be differentiated from an avulsion fracture. Generally, a fracture will have a longitudinal orientation and an irregular outline, compared to the transverse orientation and smooth contour of the ossicle. Metatarsophalangeal joint sesamoids and interphalangeal joint sesamoids. These sesamoids
1
Figure 11.18 Accessory ossicles of the foot: 1. as tibiale externum; 2. processus uncinatus; 3. as intercuneiforme; 4. parsponea metatarsalia; 5. cuboideum secundarium; 6. as peroneum; 7. as vesalianum; 8. as intermetatarseum; 9. as naviculare; 10. as trigonum.
occur regularly in varying numbers under any of the joints, and can be symptomatic. In particular, the hallux interphalangeal joint may have a sesamoid which is troublesome, particularly in a hyperextended joint. This sesamoid appears as a small ovoid on a dorsiplantar view, but may have an inverted triangular section on lateral view. Polydactyly. The presence of additional phalanges or complete digits is common enough to be seen in varying forms. Brachydactyly, the partial failure of development of a metatarsal segment or phalanges, is less common and, like polydactyly, has a hereditary predisposition (Fig. 11.20). Cases of congenital aplasia, with complete failure of development of a segment, are even more rare. Coalitions. These may take several forms, and may be fibrous (syndesmosis), cartilaginous (synchondrosis) or osseous (synostosis). The more common forms are the talonavicular bar, the calcaneonavicular bar and the talocalcaneal bar (Fig. 11.21), all of which will limit subtalar joint motion and are most easily viewed on oblique X-rays.
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-----_ ..._ - -
Figure 11.19 Accessory ossicles - os tibiale externum. In this case, os tibiale externum occurs bilaterally in a slightly pronated foot. The ossicle on the right foot is bipartite.
Other coalitions, such as intermetatarsal bars, may also be found. Suspected coalitions need to be confirmed with computed tomographic (CT) or magnetic resonance imaging (MRI) scans, which can give much more detailed images.
Bone density Bone is in a constant state of change: new bone formation by osteoblasts normally being balanced by the resorptive activity of osteoclasts. These activities are governed by the endocrine systems, and are also altered by chemical and vitamin factors in the blood, by diet, by malabsorption from the gut, by disease and repair processes and by physical forces to which the bone is subjected. The growth and maturation processes are beyond the scope of this chapter, but are well described in many standard textbooks, e.g. Parsons (1980) and Kumar & Clark (1990). An area of increased density to X-rays, which will produce a whiter shadow on the film, is known as increased radiopacity; decreased density,
Figure 11.20 Brachydactyly. There is a marked congenital shortening of the fourth metatarsal and phalanges. The digit is actually dorsally displaced, and in this case the condition was bilateral.
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tiometry (SPA or OPA) measures bone density in the forearm. Quantitative computed tomography (QCT) is an expensive method used on the spine. Investigations are under way into the effectiveness of ultrasonic scanning on the calcaneum. X-rays themselves are of little use for early diagnosis, as bone loss of 30% can occur before radiological changes are apparent. An adult foot with normal bone density will show several clearly defined features:
Figure 11.21 Tarsal coalition. In this dorsiplantar oblique view there is clear evidence of a talocalcaneal coalition. The patient had no subtalar joint motion available and was suffering increasing pain in the rearfoot. The condition was later confirmed with a CT scan (Fig. 11.35).
which will give a blacker shadow, is called increased radiolucency. The appearance of increased density of bone on an X-ray is known as osteosclerosis or eburnation, while decreased density is called osieopenia. The term 'osteoporosis' is nowadays reserved for a decrease in bone density due to pathological conditions, and will be dealt with later in the chapter. A sclerotic area will appear whiter on the film, since a greater amount of radiation will have been absorbed by the bone and osteopenic areas will be darker. Assessment of density by the naked eye is the normal everyday method, but it takes time and much experience before one may be confident of accurate judgement. There are some scientific methods for the evaluation of bone density which may be used by radiologists (National Osteoporosis Society 1993). Dual energy X-ray absorptiometry (OEXA) is used on the spine and femoral neck. Single-photon or dual-photon absorp-
• The dense outer cortices will be clearly visible as more sclerotic areas, an average of 1-2 mm thick, around the periphery of the short bones and along the shafts of the long bones, petering out at the metaphyseal areas; in the phalanges, which are considerably narrower, the cortical thickness is still maintained and thus the cortex may appear to account for a relatively larger amount of the shaft. • The medullary cavities appear as relatively radiolucent areas and the cancellous bone is traversed by fine trabecular patterns which extend into the epiphyses. The trabeculae are lamellae arranged to withstand forces and can be more marked in areas of high stress. The calcaneum often exhibits good examples of trabeculation. • The proximal and distal articular surfaces of the long bones have a fine sclerotic line around the perimeter, which is normally uninterrupted. This line may increase in thickness if the density of the bone increases when subject to extra stresses, or may disappear in certain disease processes. • The metatarsals often show a U-shaped sclerotic line at the metaphyseal junction with the epiphysis, which must not be confused with a fracture. In a juvenile foot the epiphyseal lines will still be visible as radiolucent transverse lines. The appearance of the epiphyses will depend upon the stage of development. Osteoporosis
Probably the most well-known cause of osteoporosis is the decrease in hormone production
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which occurs at the menopause: 30% of postmenopausal women will suffer significant osteoporosis, which is largely preventable with replacement therapy. It is less well known that approximately 5% of men in middle age will also develop osteoporosis (National Osteoporosis Society 1993). Hypopituitarism reduces bone growth and produces short, slender bones with thin cortices. There are delays in epiphyseal fusion. Hyperactivity of the adrenal glands, or a pituitary adenoma, may cause the generalised osteoporosis of Cushing's syndrome. There are around 11 000 sufferers from Turner's syndrome in the UK, who have undeveloped ovaries and are likely to have osteoporosis. Hyperthyroidism, which could be due to excessive thyroid hormone replacement therapy, increases the rate of bone remodelling. Faster resorption than new bone formation occurs, which may cause thinning of the cortices. Stress fractures can occur in the long bones. Interference with vitamin 0 intake or one of several disorders of vitamin D metabolism causes rickets in children, i.e. prior to epiphyseal closure, and osteomalacia in adults. Malabsorption due to intestinal disease or gastrectomy may be a factor. Sufferers from anorexia nervosa or bulimia should be considered at-risk patients for osteoporosis, as should ballet dancers and gymnasts who may deliberately starve themselves. In children this leads to characteristic deformities of wrists and legs, with enlargement and irregularities of the epiphyseal plates, and generalised osteoporosis due to failure of the osteoid tissue to mineralise. In the adult there is softening and deformation of the bones, with diminished density. There may be evidence of stress fractures. Hyperparathyroidism, due to hyperplasia of the parathyroid glands (primary type), persistent stimulation due to low serum calcium levels (secondary type) or an adenoma (tertiary type) or carcinoma, will reduce bone density by resorption of calcium salts. Not all cases will show definite osseous changes, but there may be subperiosteal thinning of the long bone cortices, particularly the digits, and distal resorption. 'Brown tumours' may be noted expanding the long bone shafts and
there may be calcification of joint cartilages, chondrocalcinosis, in long-standing cases. Osteoporosis occurs on a local level following a period of disuse of a limb: e.g. after injury or surgery when immobilisation has been employed; quite marked demineralisation can sometimes be seen, temporarily, following a metatarsal osteotomy, which quickly reverses when stress and function return. Occasionally, there is an abnormal response to quite minor injury, leading to the condition of reflex sympathetic dystrophy. As well as swelling, pain and stiffness which are out of proportion to the injury, there may be radiographic evidence of irregular mottled osteoporosis distal to the injury site. This radiographic appearance is known as Sudeck's atrophy. Autoimmune disease processes such as rheumatoid arthritis produce specific bone density changes which will be dealt with later. Finally, it is known that excessive smoking or alcohol intake may playa part in osteoporosis. Osteosclerosis
One may also see increased bone density on X-ray. Most commonly it is found in areas of higher stress, where the osteoblastic activity increases to cope with the forces. This will also be observed around healing fracture sites. In these cases the resulting bone will always be sclerotic even after the resorptive osteoclastic activity. Hypoparathyroidism, a deficiency of parathormone, results in blood calcium levels falling and phosphate levels rising. The syndrome can result in short lesser metatarsals, calcification in some ligaments of the spine and in some cases increased sclerosis. Hypervitaminosis D can lead to increased distal metaphyseal calcification and calcium deposits in the skin and periosteum. Paget's disease is a common disorder of unknown origin, although there may be inherited factors. There is speculation and research into a low-grade viral involvement. It is secondary in prevalence to osteoporosis and 0.5-1.0% of 45-54year-olds and 10-20% of those over 85 will be affected. Males are more commonly affected than
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females. Symptoms such as paraesthesia and pain are frequently related to nerve compression. The disease causes excessive bone resorption followed by haphazard new bone formation and remodelling. Isolated bones or the entire skeleton may be involved, and severe characteristic thickening and deformity may result. The foot is rarely involved except for the calcaneum. Although the bones are very enlarged and appear dense on Xray they are of poor quality; microfractures are not uncommon. It should be remembered that Paget's disease predisposes to an increased incidence of osteosarcoma and fibrosarcoma, although less than 1% progress to a malignancy. Metastatic bone disease from primary carcinomata elsewhere, such as the breast, may show sclerotic deposits, although the majority of metastases produce lytic changes. Secondary metastases are uncommon, but not unknown, in the foot. Some primary bone tumours also produce sclerotic changes, and these will be dealt with separately. Osteopetrosis (Albers-Schonberg disease or marble bone disease) is a rare hereditary disorder causing thickening of the trabeculae in all the bones; in particular there may be dense bands in the vertebrae. Although the bones are dense they are more susceptible to shear forces and may fracture more easily. Increased fluorine ingestion (fluorosis) over many years may result in the laying down of new bone inside the medullary cavity of long bones, leading to a sclerotic appearance. There may also be periosteal outgrowths. Epiphyseal, metaphyseal and diaphyseal dusplasias, which form a whole group of hereditary and congenital traits, may lead to many permutations of growth disorders, some of which involve increased bone density.
Cartilage Ordinarily one does not see cartilage on X-ray as it is radiolucent. The condition of cartilage really has to be assessed by the relationship of the adjacent bones in a joint. For example, a healthy metatarsophalangeal joint will show smoothly outlined joint surfaces evenly separated by
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1-2 mm of blackness, which represents the cartilaginous surfaces. Careful examination may reveal the approximate edges of the cartilage surfaces. In a joint which is malaligned or commencing a disease process one of the first signs will be changes in the cartilage space. This can usefully be compared to similar joints elsewhere in the foot. The space may become narrowed evenly or unevenly, may become calcified and may eventually disappear totally, for example in advanced osteoarthrosis, or may be increased in cases of joint effusion or early rheumatoid disease. These conditions will be dealt with later under the headings of arthritis and rheumatoid disease.
Soft tissue On a normal X-ray there will be very little soft tissue evident although the outline of the foot will be delineated. There will be no details elsewhere and any space-occupying lesion would have to be diagnosed purely on bony malalignment in the same way as cartilage damage. For example an intermetatarsal bursa may cause splaying of the adjacent metatarsals and proximal phalanges. It is important in the primary assessment of the film to compare soft tissue thicknesses and densities with other sections of the feet. With a 'soft' X-ray taken at a lower power there will be progressively more soft tissue visible. If the X-ray has been particularly requested for a suspected soft tissue lesion this should be clearly stated on the request form. It is sometimes possible to see the shadow of a neoplasm such as a large ganglion (Fig. 11.22), but this cannot be relied on for diagnosis. Soft tissues can become more visible when involved in disease processes. Long-standing diabetes may cause calcification of the small arteries, which appear as small white 'worms', particularly between the first and second metatarsals along the course of the dorsalis pedis artery. Similar changes may be seen in cases of hyperparathyroidism and arteriosclerosis. Other tissues may have calcareous deposits, particularly the muscles and tendons following injury, in which case the condition is known as myositis ossificans. All bursae are capable of undergoing
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Figure 11.22 Ganglion. On this dorsi plantar oblique view a large ganglionic cyst is seen arising from the lateral aspect of the tarsus. The X-ray cannot demarcate the origin. Clinically, the growth was approximately 4 ern in diameter and very tense. An incidental finding is the presence of an accessory ossicle, os peroneum, on the lateral aspect of the cuboid.
degenerative calcification. This is not uncommon at the first metatarsophalangeal joint (Fig. 11.23). Sinus tracts may also calcify. The skin and subdermal tissues may exhibit the crystalline sodium urate monohydrate deposits of gout, usually close to a joint. In untreated gout the joint will show degenerative arthritic change with characteristic punched-out erosions near the joint margins (Fig. 11.24). In pseudogout there are depositions of pyrophos-
Figure 11.24 Gout. This radiograph shows gout attacking both first metatarsophalangeal joints. The joints have clearly 'punched-out' erosions associated with gross degenerative changes. There is a large overlying bursa on the right foot.
Figure 11.23 Bursal calcification. This case of hallux abductovalgus had an overlying bursa within which was found an area of calcification. Note also the early manifestations of osteoarthritic degeneration in the joint.
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phate crystals which lead to intracapsular effusion, increased soft tissue density and increased joint space. Calcium salts may mimic gout in the condition of calcinosis cutis, a collagen disease, but the deposits, which are clearly visible, generally occur well away from joint margins. Normally, the periosteum is not visible unless pathological changes are occurring. The periosteum may become elevated and visible due to inflammation, infection or trauma and may in turn become calcified. The condition of xanthoma tuberosum multiplex, believed to be endocrine in origin, can be responsible for large, benign, clearly delineated soft tissue masses which have a marked increase in density. They can occur in relation to synovial tendon sheaths and bursae in the foot and elsewhere.
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and gives a fuzzy outline to the bone. The bone will lose density and appear hazy. In time, a loose body or sequestrum may be formed (Figs 11.25and 11.26). This can be passed to the surface by sinus formation, or it may eventually be reabsorbed or remodelled. In some cases a remodelling of the cortex may produce a sclerotic osseous shell, an involucrum, which encapsulates the sequestrum. If treatment is inefficient a chronic walled-off abscess containing debris and sometimes a sequestrum may form and can persist for years. Known as Brodie's abscess, this appears as a rarefied ovoid area and may particularly be seen at the metaphyseal areas of long bones.
Osteoarthritis The signs and symptoms of degenerative osteoarthritis are well known. On X-ray the
RADIOLOGICAL ASSESSMENT OF SPECIFIC PATHOLOGIES Infection It is important to recognise the development of infection in bone on radiographic evidence as well as by clinical presentation, although radiological changes may not be present in the osseous structures for some time. The first signs are unlikely to appear for 10 days or more. Infection may be blood-borne, or a focus from elsewhere in the body, or secondary to a direct entry wound such as surgery or a compound fracture. Although bone and joint infections can be due to diseases such as tuberculosis (dramatically on the increase worldwide), leprosy, syphilis or viral agents such as smallpox, the most common infections are the acute bacterial infections due to organisms such as
Staphylococcus aureus, Staphylococcus pyogenes, Salmonella or Haemophilus influenzae. The infection spreads firstly into the medullary bone but will not cross the epiphyseal line. One of the first signs is increased soft tissue density and swelling, which should be readily apparent on X-ray. Infection then passes through the cortex, and the pus produced elevates and strips the periosteum. The first visible osseous change will often be the subperiosteal reaction, which lifts the periosteum
Figure 11.25 Osteomyelitis. Chronic osteomyelitis in this neuropathic diabetic foot has destroyed much of the fifth metatarsal and phalanges. Note the characteristic fuzzy outline of the elevated periosteum.
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Figure 11.26 osteomyelitis.
Osteomyelitis. Almost complete destruction of the neck of the talus and all midtarsal bones, due to chronic
earliest signs are irregularity and narrowing of the cartilaginous space, which mayor may not be accompanied by deformity (Fig. 11.27). As the disease progresses the cartilage will degenerate and become calcified (chondrocalcinosis) and the joint space slowly disappears. There will be increased sclerosis, and there may be the formation of subchondral cysts. At the periphery of the joint there will be clearly visible spiky outgrowths of bone, osteophytes, which tend to grow at right angles to the long bone axis and can attain considerable size. Osteophytes severely limit joint motion and will also cause pain and pressure problems for the patient. In late stages of the disease the joint will become partially or fully ankylosed and the osteophytes may fracture, causing loose bodies within the joint capsule (Fig. 11.28). These osteophytic fractures and loose bodies are clearly visible on film. Whereas it is relatively easy to diagnose osteoarthritis in the metatarsophalangeal joints, degeneration in the midtarsal area can be masked by superimposition of the bones and may only be seen on lateral or oblique views.
Autoimmune disease There are many varieties of autoimmune disease that attack the joints, including rheumatoid arthritis, scleroderma and disseminated lupus erythematosus. Radiographic analysis is only one part of the diagnostic process, but most of the diseases produce similar radiographic features. Early changes are effusion into the joint capsule as the synovial linings are attacked, with an intracapsular increase in density. The joint spaces may increase temporarily. The epiphyses of the long bones become demineralised and as the synovial pannus invades the bone there is a progression towards erosions at the chondral margins, loss of cortex and punched-out periarticular erosions. There is a progressive loss of normal trabecular patterns and generalised osteoporosis (Fig. 11.29). Articular and bone changes are associated with progressive deformity and characteristic abduction deformities of digits. Gross subluxations and dislocations will be evident in severe cases. There is usually mid-
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Figure 11.27 Osteoarthritis. This case of hallux rigidus shows complete loss of articular cartilage and early osteophytic changes at the joint periphery. There is no deviation in the joint in this case.
tarsal and rearfoot involvement in long-standing cases. Radiographic signs of severe pronation may often be seen. In juvenile disorders such as Still's disease there may be retardation of long bone growth and premature epiphyseal closure, with 'spindling' of the digits.
Osteochondrosis This is avascular necrosis of the epiphysis or apophysis, in which there is a well-documented cycle of interference with the vascular supply to an epiphysis, possibly trauma-related but sometimes associated with endocrine dysfunction, followed by degeneration and later regeneration. It occurs in several sites on the foot, as well as in
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Figure 11.28 Osteoarthritis. This oblique view, a more advanced case than that shown in Figure 11.27, shows severe degeneration of the joint margins with obliteration of the joint space. There are multiple osteophytes, some of which have fractured away to become loose bodies within the joint capsule.
the femoral epiphysis iLegg-Calre-Penhes disease), vertebral epiphysis (Scheuermann's disease) and the tibial tubercle (Osgood-Schlatter's disease). Over 40 potential sites have been identified. In all the conditions there is a transient increase in sclerosis caused by the failure of the blood supply to remove calcium salts, followed by osteoporosis, crumbling and degeneration of the epiphysis. Revascularisation slowly occurs over a period of months and the epiphysis remodels, sometimes with residual deformity. The conditions are selflimiting and the clinical importance relates to the functional importance of the joint involved. In the foot the common conditions are as follows. Freiberg's infraction. This condition affects the lesser metatarsal heads, usually the second or
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Figure 11.30 Freiberg's infraction. The evident flattening and collapse of the third metatarsal head in this middle-aged patient is probably indicative of an old Freiberg's infraction, although this case is unconfirmed. This X·ray also shows a Keller's arthroplasty, with several loose bodies remaining around the site; an old fracture of the second metatarsal shaft; two sesamoids under the fifth metatarsal head; and a lateral exostectomy of the fifth metatarsal head. Figure 11.29
Rheumatoid arthritis. In this long-standing rheumatoid patient one may see gross derangement of all metatarsophalangeal joints, with subluxation in particular of the hallux and third and fourth toes. There is generalised osteoporosis and there are subchondral erosions, particularly seen around the first metatarsophalangeal joint. The midtarsal joints are also affected, with loss of bone density and joint demarcation.
third, at the age of about 12-14 years. An increase in the joint space may be noted due to the 'eggshell crush' degeneration that occurs in the metatarsal head. The finally remodelled head may be flattened or saucer-shaped. In later life it may produce secondary hypertrophic osteoarthritic degeneration (Fig. 11.30). Sever's disease. Sever's disease of the calcaneal apophysis usually occurs in the age range 8-12 years. An irregularity and sclerosis may be exhibited along the apophyseal line on the peste-
rior aspect of the calcaneum. However, it should be noted that the apophyseal line is frequently irregular in any case. Some authorities believe that a diagnosis of Sever's disease cannot be made with any certainty on radiographic evidence alone. Kohler's disease. Kohler's disease of the navicular occurs in youngsters in the age range 2-10 years, with a mean of 3-5 years: 70% of cases are male and there is a familial incidence. The navicular becomes dense initially, followed by porosis and collapse into a disc shape, clearly seen on a lateral view. If untreated, the bone may not regain proper form and may remain a lifelong problem. Other rarer conditions. These are Iselin's disease of the fifth metatarsal base and Buschke's disease of the cuneiforms.
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Trauma The foot is subject to a wide range of trauma, resulting in a variety of pathologies from a hairline stress fracture to major complicated fractures or the presence of foreign bodies. A careful history is required in all cases. At least two radiographic views must be taken of any suspected injury site. Fractures can be classified as follows:
• Simple fractures, where there mayor may not •
• • •
• • •
•
be displacement of the bone ends, but there is no penetration through the skin. Stress fractures, extremely fine simple fractures more usually seen on the lesser metatarsals, although the tibia and fibula are also recognised sites, particularly in runners. The fracture may be so fine as to be missed until a later stage when bony callus can be seen around the site. Suspected stress fractures can sometimes only be confirmed using isotope scanning methods. Compound fractures, where the skin has been breached by bone. Complicated fractures, where there is associated trauma or infection involving muscles, tendons and blood vessels. Greenstick fractures, which occur when the bone is bent but only one side of the cortex breaks (frequently seen in children). Comminuted fractures, in which there is splintering or fragmentation. Impacted fractures, where one bone is driven forcibly into the other. Avulsion fractures, where a chip of bone is ripped away by fibrous attachment such as muscle or ligament. Such fractures can occur in similar sites to accessory ossicles. The fifth metatarsal base is a common site for a fracture and for os vesalianum, and care must be taken to differentiate between them. Pathological fractures, which may occur due to osteoporosis or in cases of primary or secondary neoplastic bone disease.
Certain parts of the foot are prone to specific types of fracture:
• Pott's fracture occurs following a forceful direct injury or twist to the ankle and causes a spiral fracture to the fibula approximately 5-8 cm above the malleolus, and also fractures the medial malleolus. There is considerable disruption of the ankle mortise and the articular surfaces between the trochlear surface of the talus and the tibia may be damaged. • The calcaneum may suffer from comminuted or stress fractures following a fall from a height or due to disease processes. A comminuted fracture will show as a line of increased density. • The talar neck can be fractured in an incident involving forced ankle dorsiflexion. • Metatarsal and phalangeal fractures occur very commonly with all forms of injury. The normal timetable of fracture healing can be found in Table 11.1.
Table 11.1
Normal timetable for fracture healing
Time span
Process
Week 1-2
Extravasation of blood takes place between the broken ends. X-rays show sharp bone edges with or without displacement and effusion into the soft tissues.
Week 2-3
A fibrosis occurs in the initial blood clot and calcification forms between the broken ends, and may be visualised as a fuzzy plug of tissue. The bone edges will be more blurred. If the fracture is immobilised there will be little or no extra callus formation. A fracture that remains mobile will produce an increased amount of calcified tissue in the area which can be seen clearly on X-ray.
Week 3-8
Calcification in an immobilised fracture should be completed. The fracture line will disappear and remodelling of any excess bone will eventually, over a period of months, restore nearly normal, but slightly thickened contours in the bone (Fig. 11.30). A fracture which has not been immobilised, or in which the bone ends are not apposed, or in a patient with poor circulation or disease processes, may continue to delayed or non-union and exhibit osteoporotic changes with extra bone callus continuing to form; the fracture line will remain evident.
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------------ - - - - - - - - - - - - - - - - -
Foreign bodies
Neoplasia
Injuries from foreign body penetration are common in the foot and range from human or animal hairs to metal filings, glass, plastic and wood splinters. Surgical implants are also foreign bodies (Fig. 11.31). Some substances will show as areas of increased density on X-ray, but glass and wood can be difficult to recognise. More than one view is necessary to try and locate a foreign body.
The radiological diagnosis of bone tumours requires the expertise of a radiologist. A misdiagnosis could prove fatal to the patient. A complete classification of tumours with radiological features is beyond the scope of this chapter, but some of the commoner presentations are shown below. Benign bone tumours Osteochondroma (osteocartilaginous exostosis). This may occur as a solitary lesion, devel-
Figure 11.31 Foreign body - joint replacement. This X-ray shows a Swanson double-stemmed implant in situ following surgery for acute hallux rigidus. The body of the implant can only just be identified between the bone ends, with the stems extending into the medullary canals. The two titanium grommets, through which the stems pass, are clearly seen.
oping from the periosteum. It has an equal sex distribution. The tumour shows on X-ray as a mass of trabeculated bone, but it has a cartilaginous cap which is invisible. Many of these growths are asymptomatic, but others may give rise to pain due to pressure on nerves. Practitioners frequently see the pedunculated subungual exostosis on the distal phalanx of the hallux, which may have a traumatic origin (Fig. 11.32). The commonest presentation is in the femur or tibia, and the condition can exist in multiple form as an inherited tendency. Transformation to a malignant chondrosarcoma is rare, but recurrence, the presence of soft tissue shadows or increased cartilaginous thickening should raise suspicion levels. Enchondroma. These benign tumours, which may have a malignant tendency, are caused by the development of embryonic cartilage cells within the shafts of long bones such as metatarsals and phalanges. The tumour is expansile and produces areas of osteoporosis, loss of trabeculation and thin cortices, giving a 'soap bubble' appearance. Pathological fractures can occur. Figure 11.33 shows a multiple enchondromatosis or Oilier's disease. Solitary (simple) bone cyst. This is a cyst of unknown origin containing clear or serosanguinous fluid. It generally occurs in the age range 4-15 years and may only be discovered as a result of a pathological fracture. It has a predilection for the humerus and femur, but can occur in the long bones of the foot and the calcaneum. It may cause cortical thinning, with lucent areas in
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A
B
Figure 11.32 Osteochondroma. A dorsiplantar view (A) and an oblique view (B) of a subungual exostosis on the hallux, secondary to trauma. These lesions usually have a cartilaginous cap, classifying them as osteochondromata.
the medulla, but does not always expand the bone. Aneurysmal bone cyst. A sponge-like cyst with blood-filled spaces and fibrous septa, this may arise as the result of a vascular anomaly. It tends to occur in the age range 20-30 years and has equal sex distribution: 50% of the cases are in the long bone metaphyses. There is a rarefied central area with a thin cortical shell and the cyst will rapidly expand and destroy bone tissue. Osteoid osteoma. A most painful lesion which occurs most often in the long bones of the extremities, with over 65% incidence in the femur and tibia. No bones are exempt, including the feet: 75% of cases are in 5-20-year-old patients, with a sex ratio of 2 : 1 male to female. Radiologically it exhibits an ovoid translucent nidus up to 2 em in diameter surrounded by an area of sclerosis. In fact the sclerosis may be such that it masks the radiolucent area. The patient may complain of severe pain at night.
The differential diagnosis should include Brodie's abscess. Synovial chondromatosis. This condition occurs mainly in young or middle-aged males. Multiple metaplastic cartilaginous bodies form within the synovial membranes around a joint, usually the knee or shoulder but occasionally in the digits. Sometimes they will become true loose bodies within the joint. Radiographic appearance is of multiple small calcified opacities, accompanied by joint effusion and increased soft tissue density. Malignant bone tumours Osteosarcoma. The commonest primary malignant bone neoplasm, osteosarcoma accounts for 40%. It is not common in the foot, having a 50% incidence in the lower end of the femur and the upper ends of the tibia and humerus. It may occur secondarily to Paget's
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Upper
Lower Figure 11.33 Multiple enchondromatosis. Note the expansiie, thin-walled lesions in the fourth and fifth metatarsal shafts (A). The patient had similar lesions in the metacarpals of the left hand. The lesions were noted to have increased vascularity on isotope bone scans (B).
disease. An X-ray may reveal radiating 'sunray' spicules of bone raising the periosteum, although this is not particularly common, and a mixture of lysis or sclerosis within the shaft of the bone. A wedge of ossified tissue can form under the periosteum and is called Cadman's triangle. Osteosarcoma can occur, but rarely, in soft tissues. Radiologically it shows soft tissue swelling and patchy density.
Chondrosarcomas. These tumours arise from cartilaginous tissue and are second in frequency to osteosarcoma. Primary cases arise within the medulla, mainly in the long bones and ribs, with 10% of cases in the spine. Secondary cases arise from pre-existing cartilaginous pathology. The tumours occur mainly in the age range 50-70 years, with a sex ratio of 2: 1 male to female. They are rare in the foot but have been noted in
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the calcaneum. Radiologically they can be very varied in appearance, imitating other lesions, but classically they produce expansile 'grape-like' lesions, with a calcified periphery and multiple calcified central foci. Chondrosarcoma can occur in an 'extraosseous form' in soft tissues away from bone. Fibrosarcomas. These tumours are less common than osteosarcomas and occur primarily in the 40-60 age range. They are highly destructive tumours, producing expansile 'motheaten' lesions with slight periosteal reaction in the major long bones and pelvis: 50% of cases occur around the knee joint. Giant cell tumours. These tumours, of which about 15% are malignant, account for about 4% of histologically identified tumours. They occur primarily in the age range 16-45 years. There is an equal sex distribution: 50% of the growths
Figure 11.34
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are around the knee, followed in incidence by the radius and ulna, but they have been observed in hands and feet. They are vascular tumours, which on X-ray present as expanded translucent areas with a thin cortical rim. Sometimes the cortex is breached but there is no active new bone formation present and there may be little periosteal reaction (Fig. 11.34). Differential diagnosis should include the aneurysmal bone cyst. Ewing's tumour. This is a primary tumour of bone that accounts for 5% of primary bone tumours. The age range is generally 5-30 years, with the majority of cases aged 10-20 years. Initially there may only be minor porotic changes visible on X-ray, with early periosteal change and delicate spiculisation being suggestive of osteomyelitis. These later changes cause considerable tissue destruction, with a mottled
Giant cell tumour: a large vascular tumour affecting the lower end of the tibia.
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destructive appearance, cortical penetration and maybe pathological fractures. It has frequently metastasised by the time the patient is first seen. Secondary metastases. These tumours may occur in bone from malignancies elsewhere, such as the breast, kidney, prostate or bowel.
OTHER IMAGING MODALITIES Whereas X-rays provide a considerable amount of information about bone tissue, and are currently the most commonly used imaging modality, there are other methods of obtaining images which are for specific problems and deserve consideration. It should be understood that these more advanced techniques are all more expensive, and require more skilled interpretation, than plain X-rays and are very unlikely to be ordered as a first line of investigation.
Computed tomography (CT) In this technique the patient is moved slowly through a circular hole in a gantry containing a mobile X-ray generator and detectors. The X-ray tube rotates completely around the patient in a plane determined by the radiographer. The Xrays generated are picked up by an array of up to 1200 detectors, digitised and fed to a visual display screen via a computer. Hard copy images can also be produced using film. The images produced are in fact slices through the body, and they may be taken at intervals of 2-10 mm, Any portion of the body can be scanned subject to positioning limitations. The images give excellent bone details, with the cortex, medulla and trabeculae visible. Soft tissue discrimination is less than that available using magnetic resonance imaging (see later), but a trained observer will be able to differentiate muscle, fat and connective tissues. The major use of CT is the identification of bone-based pathology such as coalitions, osteochondritis or trauma, and it can be particularly helpful in the identification of avulsed or loose bone fragments in comminuted fractures (Figs 11.35 and 11.36),
Magnetic resonance imaging (MRI) At present MRI is the most expensive imaging technique, as the capital cost of the equipment is vast; however, it has the ability to produce stunningly accurate images of bone marrow and soft tissues and will prove valuable for the foot as it becomes more readily available. The image is obtained by placing the part under investigation into a strong magnetic field and passing pulsed radiofrequency signals through the field. Between the pulses the protons (hydrogen nuclei) alternately relax and realign, and emit a characteristic radiowave of their own. This can be detected and recorded, and computers are able to build a picture of the spatial relationships, density and tissue distribution of the protons. Soft tissues vary in their water content, and hence concentrations of hydrogen nuclei, both according to their nature and whether or not inflammatory changes are present, and the resultant signals therefore vary. Very detailed images of soft tissue injuries and pathology can be generated: these are high-resolution images and can be obtained in thin 'slices' through an infinite number of planes (Fig. 11.37). The best resolution images are of soft tissues, and it is possible to identify individual tendons and their sheaths, muscles, blood vessels and fat. The images are superb for identifying oedema and inflammation, as the water content of the tissues is increased, and also effusions where the water is free. On the other hand, bone detail is limited to the signals from the marrow content (Fig. 11.38). This does create an advantage as bone marrow oedema, such as in sports injuries, marrow replacement disorders, such as in metastatic disease processes (e.g. myeloma, lymphoma), and marrow infiltration, as occurs in infection, can all be identified. Specific MRI imaging techniques exist for the identification of healthy bone marrow. The STIR fat suppression technique identifies live fat and hence marrow and bone viability. Using this technique healthy bone marrow, which normally gives a white image, appears black. Diseased marrow fails to be suppressed and remains white (Fig. 11.39). The disadvantage of the lack of osseous detail is that MRI is less helpful
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297
A
B
Figure 11.35 CT scans of a tarsal coalition. This is the same case as in Figure 11.21 and shows bilateral talocalcaneal bars. The image (A) is a single frame from a series of 12 taken as 5-mm 'slices' at right angles to the subtalar joint (B) (for orientation purposes the talus is superior to the calcaneum).
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Figure 11.36 CT scan, in the transverse plane, of a comminuted calcaneal fracture with clearly shown intraarticular fragments.
Figure 11.37 Magnetic resonance imaging. A single frame from a series of slices taken in the sagittal plane. The healthy bone marrow and plantar fat pad show white, the musculature is grey, and the tendons, notably the Achilles tendon, clearly show as dark grey/black.
for assessing periosteal new bone formation, or bone fragments and fractures.
generally known as a three-phase bone scan (Table 11.2). The most commonly used isotope is technetium-99, derived from molybdenum. It is used because of its short half-life (approximately 6 hours). Other isotopes such as gallium are still used, but the trend is towards technetium. The gamma rays emitted are detected by a gamma camera positioned above and close to the patient. The radioactivity is converted into light
Nuclear medicine - isotope scanning The technique of nuclear labelling is an old one, first used in the 1940s with isotopes such as strontium-87 and fluorine-18. It relies on the fact that an inflamed or pathologically active area of the skeleton has an increased blood flow and bone activity. If a suitable radioisotope is injected intravenously with a phosphate marker it will ultimately be taken up by osteoblasts in the bone. There is an immediate distribution into the bloodstream and early images, produced by gamma-ray emissions, may be taken (phase 1 - early blood pool imaging). Further images are then taken of the blood flow into the area (phase 2 - late blood pool imaging). Normally the patient will then return 2-4 hours later for assessment of the uptake into the bone (phase 3 - bone imaging). The technique is
Table 11.2
Isotope scanning: three-phase bone scan
Phase
Process
Phase 1 (flow study)
Images are taken every 5 s for 30 s, giving an indication of blood perfusion into the area
Phase 2 (blood pool study)
Images taken when the area is fully perfused
Phase 3 (metabolic study)
An image taken 3-4 hours later, giving an indication of the amount of isotope tracer that remains bound to bone
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Figure 11.39 MRI STIR fat suppression technique of the case shown in Figure 11_38. In this image the healthy bone marrow appears black and the diseased marrow fails to suppress and is very clearly demarcated in white. Figure 11.38 MRI scan in the sagittal plane, showing the destruction of the medial cuneiform and first metatarsal by chronic osteomyelitis secondary to diabetes (Charcot's foot). Note that the healthy bone marrow is white, whereas the diseased bone marrow appears grey.
photons, multiplied and enhanced electronically and displayed on a screen. The image consists of a pattern of dots forming the osseous outline, with the greatest concentration of dots in the area of greatest isotope uptake. Such areas of increased uptake indicate increased osteoblastic activity in the area (Fig. 11.40). This may be due to any inflammatory process such as a primary or secondary neoplasm, injury, stress fracture or infection. The uptake can be negative in areas of rampant bone infection with destruction. The technique has one great advantage in that it enables detection of bony pathology at a very early stage, unlike other imaging techniques, and it may provide clues in unexplained bone pain. Osteomyelitis and aseptic necrosis may be detected at the earliest stages, and serial scans may be used to track the progress of disease. However, it is important to note that whereas this form of imaging is highly sensitive for pathology, it is very nonspecific: e.g. the increased uptake may be due to any inflammation, tumour, Paget's disease, injury, stress fracture or infection. The residue of an isotope scan may remain for months or years
within the tissues, and this can limit the usefulness of the technique in subsequent disease such as acute or chronic infection.
Fluoroscopy There are certain circumstances, notably during operations, where instant images are required, and the technique of fluoroscopy may be useful, particularly for the localisation of pins, screws, prostheses or foreign bodies. X-rays are used to cause fluorescence on a screen, most commonly containing caesium iodide. The resultant images are intensified and fed to a display monitor or camera. Modern fluoroscopes can take a series of time-delayed images which, while not a moving picture, are very adequate. This drastically reduces the radiation dosages.
Ultrasound Ultrasound examinations involve using reflections of pulsed sound waves to detect differences between soft tissue interfaces. Echoes are reflected by changes in tissue density, and the use of higher frequencies gives higher-resolution images but less penetration of tissue. Typical frequencies used in foot examination are in the order of 7-10mHz. The waves are totally
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Figure 11.40 Large synovial tumour (pigmented villonodular synovitis) which destroyed the second metatarsophalangeal joint A. X-ray which shows the marked erosions and soft tissue swelling. The diagnosis was aided by the use of a technetium-99 isotope bone scan. 81 shows the phase 2 late blood pool phase and 82 shows the phase 3 bone imaging, both of which confirmed greatly increased osteoblastic uptake.
reflected by bone, and this limits usage to the examination of superficial soft tissues, e.g. examination for partial or complete rupture of the Achilles tendon or for plantar digital neuroma. An extension of ultrasound is Doppler imaging, which can detect and measure blood flow and direction in major arteries and veins. The smallest artery measurable in the foot would be dorsalis pedis. The images are colour-based, with arteries appearing red and veins blue. Doppler imaging has obvious applications in vascular and diabetic departments. Whereas ultrasound has the advantages of being relatively cheap, non-invasive and portable (modern machines can be used in a patient's home if required), it is very labour-intensive and the
interpretation of results requires a very skilled operator. The images are transient and, hence, very observer-dependent.
SUMMARY Imaging techniques provide considerable information about many pathologies, but these techniques should only be requested to aid diagnosis and provide effective treatment. Plain X-rays will always have a major role in the diagnosis of foot pathologies. However, the foot specialist must keep abreast of technological developments such as CT scanning, MRI and nuclear isotope scanning, which may become more accessible in the future.
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REFERENCES Kumar P J, Clark M L (eds) 1990 Clinical medicine, 2nd edn. Bailliere Tindall, London National Osteoporosis Society 1993 Menopause and osteoporosis therapy. GP manual. National Osteoporosis Society, London National Radiological Protection Board 1988 Guidance notes for the protection of persons against ionising
radiations arising from medical and dental use. HMSO, London Parsons V A 1980 Colour atlas of bone disease. Wolfe Medical Publications, London Swallow R A, Naylor E, Roebuck E J, Whitley A S 1986 Clark's positioning in radiography, 11th edn. Heinemann, London, pp 89-107
FURTHER READING Aird EGA 1988 Basic physics for medical imaging. Heinemann, London Berquist T H 1990 Magnetic resonance imaging of the foot and ankle. Seminars in Ultrasound, CT and MR 11(4): 327-345 British Institute of Radiology 1992 Pregnancy and work in diagnostic imaging. British Institute of Radiology, London Bushong S C 1997 Radiologic science for technologists, 6th edn. Mosby, St Louis Gamble F 0, Yale I 1975 Clinical foot roentgenology, 2nd edn. Krieger, Basle McKillop J H, Fogelman I 1991 Benign and malignant bone disease. Clinician's guide to nuclear medicine. Churchill Livingstone, Edinburgh
Murray R 0, Jacobson H G, Stoker 0 J 1990 The radiology of skeletal disorders, 3rd edn. Churchill Livingstone, Edinburgh Pavlov H 1990 Imaging of the foot and ankle. Radiologic Clinics of North America 28(5): 991-1017 Rogers L F 1982 Radiology of skeletal trauma, Vol 2, 3rd edn. Churchill Livingstone, Edinburgh, ch 22-23 Root M L, Orien W P, Weed J H 1977 Clinical biomechanics, Vols 1 and 2. Clinical Biomechanics Corporation, Los Angeles, California Taussig M J 1979 Processes in pathology. Blackwell Scientific Publications, Oxford Warren M J, [effree M A, Wilson 0 J, MacLarnon J C 1990 Computed tomography in suspected tarsal coalition. Acta Orthopaedica Scandinavica 61(6): 554-557
CHAPTER CONTENTS Introduction 303 How can gait be analysed? Observation of gait
304
304
Methods of quantitative gait analysis Temporal and spatial parameters 306 Kinetics of gait 308 Accelerometers 313 Kinematics 313 Electromyography (EMG) 315 Energy expenditure 315 Multisystems 316
306
Methods of analysing gait c. Payne*
Summary 316
INTRODUCTION Gait analysis is the systematic analysis and assessment of human locomotion. Gait is a very complex activity and as such there are many different ways to analyse it. The use of gait analysis combined with a thorough clinical orthopaedic assessment (Ch. 8) are powerful tools for identifying pathomechanical mechanisms, guiding therapeutic interventions, making treatment decisions and monitoring the outcome of interventions. However, the identification of cause from effect is often difficult because of the highly developed compensatory feedback which operates during the gait cycle and the occurrence of more than one pathology at the same time. Gross abnormalities, such as a patient with a marked limp or a child who is a toe walker, are relatively easy to identify. Minor variations from the 'normal' cause more difficulty and are harder to spot and describe in a meaningful way. This is not surprising if one considers how fast events occur during walking: it takes only 650 ms to complete one full gait cycle. Practitioners are therefore increasingly looking towards methods of investigating gait in a systematic way which provides accurate, reproducible and quantitative data. There is no single satisfactory method of analysing and quantifying gait. Additionally, technological advances in this field are rapid, especially in the development of software to assist in "The editors wish to acknowledge the work of Steve West. This chapter is based on his work in the previous edition.
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the interpretation and analysis of data collected by more sophisticated systems. New systems are continually being developed. The reader is therefore recommended to review medical and engineering journals to keep abreast of developments.
HOW CAN GAIT BE ANALYSED? Gait can be analysed by observation or by a variety of methodologies which produce quantitative data: • • • • • • •
temporal and spatial parameters kinetics accelerometers kinematics electromyography energy expenditure multisystems.
Clinically based gait analysis methods include observation and simple quantitative methods that provide useful data. Observation of a patient's gait can be assisted by the use of video and treadmills. Simple quantitative measures can be achieved from techniques using paper, pen, tape measure and stop watch. Clinically based methods are simple to use, can provide repeatable data and are relatively easy and relatively quick to interpret. They are also relatively low tech. Laboratory methods are reliant on sophisticated and expensive equipment, which can be quite costly. Specialist knowledge is required to use and interpret the data. Purpose-designed gait facilities can provide an adjunct to the clinical examination but are often used solely for research purposes.
OBSERVATION OF GAIT Observational or visual gait analysis is the analysis of a subject's gait without the use of any equipment and is one of the more useful and widely used clinical tools available to practitioners. The analysis of gait in this way is subjective and needs a substantial understanding of normal gait (Inman et al 1981, Perry 1992, Rose & Gamble 1993). Observational gait analysis involves watching
a person walk up and down an area that allows sufficient space for up to 10 steps, usually a corridor in the clinical setting. Any deviations from the assumed normal that are relevant are noted. Observational gait analysis is best done by systematically concentrating on one body part at a time, then another, and usually one limb at a time. With experience many gait deviations can be observed. The difficulty of observing one body part at a time is that multiple movements in multiple segments are occurring concurrently and need to be observed. Checklists, such as the one provided in Table 12.1, are usually helpful to work through, especially when learning. Traditionally, the approach is to observe the limb as it moves through the different periods of the stance phase - heel contact, midstance, propulsion. Another approach (Pathokinesiology Service 1993) is to divide gait into weight acceptance (initial contact and loading response), single limb support (period when body progresses over single limb, and swing limb advancement (time when one limb is unloaded and the other limb is loaded) and note variations from normal during these phases. A standardisation of the form to record gait analysis has been presented by Southerland (1996). The approach has introduced a shorthand form of notation for recording during gait analysis referred to as GHORT (gait homunculus observed relational tabular). Readers are referred to Southerland (1996) for detailed information. In clinical practice, the observational analysis of gait is usually used after the history and physical examination of the patient in order to evaluate the presence of any abnormal function that may be responsible for the patient's presenting complaint. The subsequent more detailed static and nonweightbearing biomechanical evaluation can be guided to particular areas of interest by the gait analysis. Of importance at this stage of the clinical evaluation is a consistency between the observed gait and the findings of the biomechanical evaluation. For example, if a lot of transverse plane motion of the midfoot is observed in stance during the gait analysis, a similar increase in the transverse plane direction of motions at the subtalar and midtarsal joints should generally be observed.
METHODS OF ANALYSING GAIT
Table 12.1
Practical observational gait analysis
• Observe for amounts and timing of events • Look for asymmetry Concentrate on one aspect at a time Bisection of caicaneus and posterior aspect of leg is often helpful A mark on the medial side of the navicular is also helpful • Be aware that many individuals may consciously or subconsciously alter gait while being observed At least an 8-10 metre walkway is desirable with provision for watching subjects from behind/in front (frontal plane) as well as from the side (sagittal plane) • Patient should be wearing shorts • Observe with and without shoes and with and without orthoses Frontal plane observations: Upper body: Head/eyes level or tilted? Shoulders level? Height of finger tips Symmetrical arm swing Pelvis level or tilted? Lower limb: Position of knee Q angle/patellar position Timing of knee motion Position of tibia Timing of tibial rotation Foot: Timing/amount of rearfoot motion Timing/amount of heel contact/off 1iming/amount of midfoot motion Transfer from low gear to high gear during propulsion Angle and base of gait Abductory twist? Prominent extensor tendons (extensor substitution) Clawing of digits (flexor stabilisation) Sagittal plane observations: Upper body: Forward or backward tilt Symmetrical arm swing Lower limb: Position/timing of hip joint motion Position/timing of knee joint motion Position/timing of ankle joint motion Foot: Timing/amount of heel lift Timing/amount of midtarsal joint motion Timing/amount of first metatarsophalangeal joint motion
There is a tendency in clinical practice to focus on frontal plane motion during the gait analysis when motion in the transverse and sagittal planes are just as important to appreciate gait. This primarily occurs for several reasons. Most clinics only have long corridors available which facilitate the observation in the frontal plane but
305
hinders sagittal plane observation. The traditional teaching of clinical biomechanics places great importance on frontal plane compensation for different pathomechanical entities, which encourages the use of observation of gait to observe frontal plane motion of the posterior aspect of the calcaneus. The observation of the calcaneus in the frontal plane is easy, but is not necessarily indicative of any abnormal or compensatory gait patterns. For example, any abnormal compensatory movement of the calcaneus in the frontal plane is entirely dependent on the range of motion of the joints of the rearfoot complex and the orientation of the assumed position of the subtalar joint axis. If the axis is more vertical than the assumed normal, there will be very little motion of the calcaneus in the frontal plane, with more in the transverse plane. If the axis is more horizontal, there will be more motion in the frontal plane, which may not be pathological. Observational gait analysis is also limited by the ability to observe transverse plane motions and the difficulty to observe and interpret motion in all three planes simultaneously as well as motion occurring simultaneously at several joints. In a clinical setting in patients with pathology, the observation of gait requires them to walk for some time, which can be fatiguing for them. The endurance of the patient needs to be considered. There is no permanent record from observational gait analysis - no opportunity to review the data at a later date. The analysis is very dependent upon the skill and experience of the observer. All the data are subjective and qualitative. When one observes an individual standing on both feet, it is impossible to predict whether the load (distribution of force) under both feet is equal. This highlights the fundamental drawback of observation of gait: you cannot observe forces and the eye can be easily deceived. Reliability studies on observational gait analysis show it to be somewhat unreliable (Goodkin & Diller 1973, Krebs et al1985, Saleh & Murdoch 1985). Despite these limitations observational gait analysis provides a good overall impression of gait and requires no equipment. Experienced observers use observational gait analysis to make critical
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judgements, assist in diagnosis and determine the outcomes of interventions such as foot orthoses. Treadmill. One of the most debated areas of gait analysis relates to the length of walkway required in order to achieve 'normal' walking patterns: 4-6 metres is considered appropriate. Many practitioners have heightened the debate by using treadmills rather than long walkways. If a treadmill is used, one must ensure that the subject has every opportunity to adapt to treadmill walking prior to analysis being undertaken. This usually requires at least 15 minutes of walking on the treadmill. The more exposure to treadmills, the shorter the time recorded to acclimatise and perform consistently (Tollafield 1990). Clearly, older patients and those with medical conditions are likely to fatigue more quickly. No matter how sophisticated the system is, subjects must feel relaxed and comfortable when being observed. Most authorities now accept that in order to achieve this objective, the subject should be allowed to walk at his/her own cadence rather than being artificially constrained by walking in time to a metronome or some other timing device. A forced gait is of no value to a practitioner attempting to assess walking patterns. For visual observation, treadmills facilitate closer inspection of the gait as well as easy observation of gait in the sagittal plane. Additionally, treadmills are relatively inexpensive. However, safety and balance of patients need to be paramount in their use. There are subtle differences between overground and treadmill gait that need to be taken into consideration, especially during the propulsive phase, as on the treadmill the 'ground' is moving. Video. Videotaping of a movement for analysis (overground or on a treadmill) is an improvement on the traditional gait analysis. Observational gait analysis is limited by the speed that motions happen at, meaning that the more subtle motions cannot be observed in real time. Many movements take place in a very short time period. It has been observed that events that happen faster than 83 ms 0/12 second) cannot be perceived by the human eye (Gage & Ounpuu 1989), so the use
of slow-motion video and freeze-frame can enhance observational gait analysis. With good pause and slow-motion facilities the finer and subtle features of gait that would otherwise be missed can be observed. This will be dependent on the frequency of sampling: below 30 Hz would be unsuitable, 50 Hz is the minimum for slow walking and 100 Hz would be required for running, or too much movement happens between each sampling frame to make the information of any use. If two cameras and a video mixer are used, it is possible to view gait in two body planes simultaneously on the same split screen eliminating the problem of cross-plane interpretation. Initially, many practitioners do find the two views confusing. Videotapes can be archived for subsequent viewing and the comparison of before and after gaits following an intervention. Recent advances in computing now allow the taping of gait (either the traditional videotape or digital) to be viewed on a computer. Some systems (e.g. 'Irim-Fit'P') allow the drawing and calculation of angles between segments, the generation of gait analysis reports and the linking of the recorded gait into the patient's computerised records. Disadvantages to the use of videotaping gait are that the rotational deviations in the transverse plane cannot be seen. Movements out of the plane of the camera can also distort joint angle and influence interpretations: e.g. if sagittal plane knee motion is being observed, the angle may appear less than it really is due to internal rotation of the limb. The analysis of the videotape is still qualitative and has been shown to be only moderately reliable (Eastlock et al 1991, Keenan & Bach 1996), but it is an improvement on the straight visual observation of gait.
METHODS OF QUANTITATIVE GAIT ANALYSIS Temporal and spatial parameters As gait is repetitive, the measurement of the temporal (time) and spatial (distance) parameters are an aid to evaluating critical events that occur
METHODS OF ANALYSING GAIT
307
._-- ----------
during gait. These parameters include stride length, stride time, step length, step time, double support time, mean walking velocity, cadence and the ratios of left to right of these parameters. It also includes toe-out/toe-in angles and width of the walking base (base of gait). These parameters are useful as a measure of an individual's functional ability to ambulate: for example, less time will be spent in single limb support if that limb is painful. Step length. This parameter is the distance from initial heel strike of one foot to the heel strike of the opposite foot. Cadence. This parameter is the number of steps taken per unit time, usually per minute. For practical purposes, practitioners tend to count the number of steps taken during a period of 10-15 s. When measuring cadence it is important that subjects are told to walk at their normal walking speed and as naturally as possible. The observation count starts once the subject is walking at normal speed. To estimate average cadence per minute the following formula should be applied: Cadence (steps per minute) = steps counted x 60/time(s) Stride length. The distance between two successive placements of the same foot, stride length will therefore consist of two step lengths; this parameter is usually measured in metres. The walking base. Also known as stride width, the walking base is the distance between the feet, usually measured at the midpoint of the heel; it is recorded in millimetres. Toe-out and toe-in. These parameters are a measure of foot position in relation to the line of forward progression. It has been shown that foot position in relation to the line of forward progression constantly changes during gait. To produce an 'average' the position the foot adopts for 10 steps is recorded and the mean is calculated. The velocity of walking. This parameter, measured in metres per second, is the distance covered by the body in a given time in a particular direction. The mean velocity can be calculated as the product of cadence and stride length. The cadence is measured in half strides per 60 s or full
strides per 120 s. The velocity can be calculated by the following formula: Velocity (m/ s) = stride length (m) x cadence (steps/min)/120 The above parameters can be recorded with basic equipment and can provide valuable clinical information (Kippen 1993). Poster paints, talcum powder, chalk, plaster of Paris, carbon paper and various coloured inks have been used to obtain footprint impressions (Wilkinson & Menz 1997). These footprint impressions provide a permanent record of the foot placements during gait and can be used to calculate a variety of parameters, as indicated in Figure 12.1. Foot switches can be used to determine temporal parameters; these are inexpensive and simple to use. The switches are either of a compression closing type or force sensitive type. They are typically used under the heel, first metatarsal and fifth metatarsal incorporated into an insole or strapped to the area of the foot. They are activated when a certain threshold of pressure is applied. Foot switches can be used in combination with other systems, such as electromyography, so that the timing of critical events such as heel contact, forefoot contact, heel off and forefoot off can be determined in relationship to other variables or parameters being measured. Gait mats (e.g. GaitRite™, GaitMat™) consist of a long strip of walking surface that has embedded in it an array of switches running along the length and width of the mat. As subjects walk on the mat, the switches close and open, allowing the computer to calculate the timing of each switch. As the geometry of the mat is known, many of the temporal and spatial parameters of gait, such as cadence, timing of single and double support duration and stride length, can be determined. These systems have the advantage of being relatively low cost and are portable. The measurement of temporal and spatial parameters can highlight pathology and changes associated with disease or rehabilitation. Patients such as those with rheumatoid arthritis, Parkinson's disease or paralysis will all show significant deviations from 'normal' parameters,
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Kinetics of gait
Base of gait
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Ol
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Figure 12.1 Spatial parameters that can be measured using a simple walkway,
e.g. short stride length, slow or fast cadence. However, it must be recognised that assessment of these parameters on their own is not sufficient for a comprehensive overview of gait. Spatial and temporal parameters vary during walking and from one period of walking to another. Consequently, it is important to view the data with caution and to obtain a mean average for any parameter.
This is the study and measurement of forces and moments exerted on the body that influence movement. Of direct relevance to the practitioner is the recording of forces at the foot/floor interface, measured, for example, via force platforms. Lesion patterns give an indication of the site of excess stresses but quantitative information cannot be gained by observation (Duckworth et aI1985). Consequently, some method of examining the plantar load distribution must be employed. Many authors use the terms 'force', 'load' and 'pressure' interchangeably. This practice is to be discouraged. It is worth defining these terms and others used in biomechanics (the study of the effect of mechanical laws on the locomotor system) from the outset. Force. As defined by Newton's second law of motion, Force is mass multiplied by acceleration. This law means that any time a force is applied to an object, the object accelerates. Since acceleration is the change in velocity divided by the change in time, a force applied to an object will produce a change in the object's velocity. Force can therefore be considered as change in momentum divided by change in time. Force is a vector quantity, having both magnitude and direction. Pressure. Pressure is force divided by area: the larger the area the lower the pressure. This unit has important implications when comparing different measurement systems for measuring pressure under the foot. For example, systems which have large discrete element sizes may not be able to measure the true pressure under a small area of the foot. Researchers and practitioners are interested in the interaction between the foot and shoe. The fundamental questions being asked are: • Is there a correlation between the loading characteristics of the shod and unshod foot? • What happens at the foot/ shoe interface? • Is there a correlation between the loading characteristics measured at the shoe/floor interface and those at the foot/floor interface? • Are the effects of foot orthoses influenced by the type of footwear?
METHODS OF ANALYSING GAIT
309
History has seen the development of a variety of systems designed to study the way in which load is distributed over the plantar surface of the foot. In addition, reviews of clinical findings employing particular equipment are continually being published. Many systems described in the literature are designed as part of research projects. These systems have not appeared on the market because of cost, lack of repeatability and technical difficulties that make them difficult to use clinically. The systems currently available to practitioners are: • • • • •
Harris & Beath mat pedobarograph force plates Musgrave footprint in-shoe force measurement.
Harris & Beath mat
A deformable mat printing technique first employed by Morton in 1935 was modified and adapted for flat-foot studies (Harris & Beath 1947). A three-ridged rubber mat, of 0.002,0.0025 and 0.0028 inches in height, was designed. The ridged top surface of the mat is spread thinly with soluble printer's ink and then placed on the floor, ridged side up. The mat is covered with a clean sheet of white paper and a static or dynamic footprint is recorded on to it. The differing heights of the ridges produces the effect of increased density of ink in areas of high pressure (Fig. 12.2).An attempt to calibrate the print mat using known size and weight has shown promise but still offers only broad bands of pressure ranges (Silvino et al 1980). This has enabled quantitative data to be collected. Many other authors have adopted the Harris & Beath mat for varying forms of foot analysis (Henry & Waugh 1975, Kilmartin & Wallace 1992, Rose et al 1985, Welton 1992, West 1987). The clinical application of the Harris & Beath mat is far reaching. It can provide data on foot dimensions including foot length, width, arch profile and total foot contact area. In addition, valuable information about loading of the foot can be gathered; high and low loaded areas can be identified.
Figure 12.2 Beath mat.
An example of a footprint from the Harris &
Pedobarograph
The pedobarograph was first described by Chodera in 1960 and was developed for the investigation of plantar foot pressure measurements. This simple optical system has been used in static and dynamic pressure measurement studies (Betts & Duckworth 1978, Betts et al 1980a). Essentially, the pedobarograph is based on the interruption of a light source by total internal reflection through the highly polished glass edges of a glass plate acting like a lens. An elastic or textured foil is placed between the light-conducting surface and the plantar surface of the foot. Light internally reflecting along the glass is affected by the pressure applied to the foil. The light illuminates the foil, which scatters the light back in the area of the pressure. The patterns of the pressure area can be observed and recorded by a camera housed inside the pedobarograph box. Internally, a mirror is angled at 45° to the glass platform, which reflects
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the light image into the lens of the video camera. The pattern observed shows the areas of increased light intensity with pressure. The video output can be captured via a frame grabber and then manipulated and analysed by software (Fig. 12.3). The pedobarograph is a non-portable system that requires a raised walkway into which it can be placed. The images produced provide high spatial resolution in continuous greyscale or 16 colour zones. The pedobarograph has been well documented using both dynamic and static data (Betts & Duckworth 1978, Betts et al 1980b, Hughes et al 1990, Minns & Craxford 1984). In most of these studies authors have used computer imaging techniques to zone the greyscale images and enhance them with colour. Several investigations have been undertaken to establish the effects of different foil characteristics on the light intensity emitted. One study by Betts et al (l980b) suggested that photographic paper with a pearl finish would be a suitable foil for calibrated dynamic foot pressure measurements. In
their study it was found that the paper showed little viscoelasticity, tackiness or other hysteresis-like effects and no evidence of saturation over the pressure range studied. Hysteresis is the lag between the release of stress and the cessation of strain in materials subjected to tension or magnetism. This work highlighted the need for careful interpretation of the data. The systems employed to measure load have within them characteristics that can affect the data. For example, the characteristics of the foil, when measuring static loads, could provide loading data that was too high or too low because of the response time and hysteresis of the material. The recovery time and recovery characteristics of the material, once it has been loaded and unloaded, is especially important when investigating dynamic loading. In the early pedobarograph studies not only was the material slow to recover from loading but it also became tacky and tended to stick to the glass surface even when unloaded. This gave a false loading as a result of
Foil Shielding
~----
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Light source
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--- --Camera Figure 12.3
Cross-section of a pedobarograph.
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METHODS OF ANALYSING GAIT
the foil characteristics. The pedobarograph system can be calibrated and can measure pressures to 25 kg/ em? (2.45 MPa). Recordings have been made of both static and dynamic loading with feet considered to be normal and abnormal. It has been stated that the distribution of load between the sole of the foot and a supporting surface can reveal information about both the structure and the function of the foot (Lord 1981). As mentioned previously it is desirable to investigate the way in which the plantar surface of the foot bears and transmits loads. Force plates
Force plates allow the measurement of vertical and shear forces and centre of force application under the foot. Force plates (e.g. Kistler'P', AMTFM, Bertec'?') are fixed to the ground and are used to measure the ground reaction forces exerted as the patient walks on to the plate during gait. The plates normally need to be set in epoxy concrete to prevent interference from vibration, although these vibrations can normally be identified and ignored on gait data. Force plates consist of a top plate that is mounted level with the surrounding floor. The top surface of the plate can be glass, aluminium or steel. The top plate is separated from a bottom frame by force transducers mounted at each corner. The force transducers are either piezoelectric - which use quartz transducers to generate an electric charge when stressed - or strain gauges. In the Kistler force plate, the plates incorporate four quartz rings which exhibit a piezoelectric effect, thus ensuring the system is sensitive to force in three planes: x, y, z. The control unit outputs continuous analogue data via 13 channels, of which eight are normally used. The only limitation of the system is the speed at which data can be received and stored and the analogue-to-digital converter interface, which can limit the resolution in time. Each channel can be sampled up to 3000 times per second. The collected data can be displayed on the computer's VDU as digital information or as a series of graphs showing force against time before obtain-
311
ing a hard copy print. The system provides detailed numerical and graphical data on the forces applied to the foot (Fig. 12.4). The system has poor spatial resolution and does not analyse discrete pressures on the plantar surface of the foot. However, it should be noted that it can be calibrated and has been used to calibrate other force measurement systems. Musgrave footprint
The Musgrave footprint is a computer-based system that can be used for the measurement of plantar foot pressures. The footplate is a lowprofile plate which uses Interlink force sensitive resistors (FSRs) between aluminium plates. The plates are often used in pairs to provide data of
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LABORATORY AND HOSPITAL INVESTIGATIONS
both a temporal and spatial nature. The system is interfaced through a standard PC and is therefore relatively portable. The Musgrave plate can be calibrated and can record pressures up to 15 kg/ em- (14.4 MPa). It produces data which can be displayed graphically, numerically or visually. The data presentation is clear and easy to interpret. Young et al (1993) undertook a comparative trial of the system against a pedobarograph and found that the Musgrave plate was unable to measure pressures above 15 kg/ cm-. Such pressures have frequently been observed under the metatarsal heads of diabetic patients. The work concluded that in low-pressure areas such as the heel the Musgrave footprint could provide comparable results to the pedobarograph. The Musgrave footprint tends to illustrate vertical force as pressure values and cannot differentiate high shear force values. Callosity under the foot may not show high values unless the load under the foot has a long duration of contact with the pressure platform. In-shoe force measurement
Many methods have been developed for recording foot loading while the foot is shod. Piezoelectric discs have been attached to the plantar surface of the foot to record the different effect of heel height on forefoot loading (Schwartz & Heath 1947). Capacitive pressure transducers have been stuck to the sole of the foot to record peak pressures in predetermined areas during gait in patients affected with Hansen's disease (Bauman & Brand 1963). Strain gauge transducers have been attached to the forefoot and hindfoot of the sole of the shoe to record the total floor reaction. By this method it was possible to record the heel and sole forces separately (Miyasaki & Iwakura 1978). An insole for recording plantar pressures was developed by Lereim & Serek-Hanssen (1973) in which miniature transducers were accurately positioned against the sole of the foot by the use of Xrays. These were then incorporated into a PVC insole to be worn in the shoe. New insoles had to be made for each subject.
Insole pressure measurement systems have become commercially available, e.g. the German Emed system, the Italian Orthomat and F-Scan. The Emed system belongs to a class of devices characterised as matrix mats. In these devices, the individual sensors are formed electronically at the intersection of rows and columns of conductive material (Nicol & Henning 1978). The F-Scan insole system consists of a printed insole approximately 300 mm long, 105 mm wide across the forefoot, 70 mm wide across the heel and 0.02 mm thick. The insole is a multilayer, piezoresistive, screen-printed sensor sandwiched in a moisture-resistant coating. The layers are held together by small glue spots at a repeat distance of 1 cm square. This allows the sensor insole to be cut to fit any size of shoe down to an adult size 4, providing care is taken not to cut through any required silver connecting tracts. The ink tracts provide multiple sensors of identical characteristics. The sensors relay data (Fig. 12.5) via silver tracts which are banded together to exit the foot on the lateral aspect and insert into a small, lightweight signal processing unit worn by the subject just above the lateral malleolus. The data are presented to the practitioner via a screen and/ or a printer supplying a one-to-one sized printout. The data presentation and collection is achieved via a user-friendly programme using windows and graphic display keys that allows for several alternative data display modes. The insole sensors do not show a linear relationship between resistance and pressure; algorithms in the software are used to assign levels to pressure. Since this is not linear, different ranges can be achieved for high or low pressures. The insoles have a range from 0.57 kg/ em? (56 kPa) to 8.85 kg/ em? (868 kPa). The insole unit may be sensitive to temperature and moisture changes. However, well-controlled protocols may be able to reduce this characteristic. Repeatable data collection runs are achievable provided that the sensors are undamaged. Most investigations use each insole unit for a maximum of five data collection runs or approximately 40 gait cycles. The sensor has been
METHODS OF ANALYSING GAIT
Y-axis
t ____
.~~
X-axis
313
The advantage of the system is that it provides a method for measuring plantar loading of successive steps of each foot while the foot is shod. The foot can be analysed for up to 6 sand the foot-to-shoe or foot-to-orthosis interface can be investigated directly. The system is being developed to further increase the loading range of the insoles so as to achieve a more acceptable working range to allow analysis of running foot pressures and loads seen in pathological feet.
Accelerometers
10 mm
: .--11--:
-.11 lmm
~
l.
Figure 12.5
10 mm
.
Diagrammatic representation of F-Scan.
shown to exhibit significant decay after this (Rose et al 1992). Unpublished work suggests that the sensor, if laminated with a thin backing material, produces valid and reliable data throughout its working load range for 200 gait cycles. The sensors have shown failure with respect to total breakdown of the silver relay tracks, and loss of individual sensors as a result of marked creasing or cutting. It has also been noted that sensors can be permanently switched on, registering maximum loads. This is thought to be as a result of sensor damage during cutting the insole to fit shoes. Software modifications in the future may allow investigators to delete 'hot' sensors prior to data analysis.
The use of accelerometers in gait analysis has generally been confined to the measurement of impact forces such as those seen at heel strike. Much work has been undertaken by sports footwear manufacturers in the quest for the ideal shock-attenuating insole unit. The 'shock meter' system has been used to investigate shock waves transmitted during gait (Johnson 1990). A few experiments have been undertaken using accelerometers mounted on pins and then screwed directly into the bones of volunteers, although this method is clinically unacceptable. Accelerometers have been used to measure acceleration of body parts during motion (Morris 1973). Accelerometers have been used in research but in clinical practice they may not be of much value (Collins & Whittle 1989).
Kinematics Kinematics describes angular movement and displacement of joints and the body throughout space. There are a variety of ways in which these data can be measured directly and indirectly. Direct method
Direct measurement can be achieved by using goniometers (Chao 1980). These measure joint angle changes. The use of goniometers is becoming increasingly common, especially electrogoniometers and flexible goniometers (Fig. 12.6). Electrogoniometers (e.g. Biometric'Y) are electromechanical devices that span a joint,
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II
Figure 12.6 Electrogoniometer with transducer capable of reading 0.1 0 of motion (Penny & Giles, Gwent, UK). The goniometer has been attached to the foot to record subtalar motion.
being attached proximal and distal to the joint in the plane of motion that the joint generally moves in. They consist of two rigid links that are connected by a potentiometer that gives a voltage output proportional to the change in angle between the two rigid links. The angle the joint moves through is recorded in a data collection unit. Foot switches can be used to record events such as heel contact and toe off, so the timing of the motion can be determined. Electrogoniometers can be used to measure twoor three-dimensional joint motion. They are of low cost and are relatively easy to use. The equipment requires careful calibration and setting up in order to achieve valid and reproducible results. Some patients complain of being impeded by the measurement systems. This will affect the results obtained. Measurement of the small joints within the foot during gait has been more of a challenge and has led to the development and production of small flexible goniometers.
Indirect methods
Cine photography was the principal technique for gathering kinematic data prior to the introduction of video systems. Muybridge (1955) pioneered the use of cine photography in the study of human and animal locomotion. This work was a classic and is still used by scientists and artists today. In the book Human walking, Inman et al (1981) demonstrate how the use of cine photography and still pictures can provide valuable information about joint angles and limb placement during locomotion. Data analysis of limb movement became much easier and quicker, although still too slow and time-consuming for routine clinical applications, following digitisation of the images (Sutherland & Hagy 1972). Modern cine and video recording devices are now available and can be directly interfaced with a computer. Video motion based systems (e.g. APASTM, Expert Vision'P', Opotrakr'<, Vicon P', Peak PerformanceP', MacReflex™) use one or more cameras to track markers that are attached to subjects at various locations. The markers are either active or passive. Active markers are infrared light-emitting diodes and the passive markers are reflective solid shapes. The video cameras keep track of the coordinates of the markers: in threedimensional systems, the computer software keeps track of the three-dimensional coordinates of each marker based upon the two-dimensional data from two or more cameras. Two-dimensional analysis is cheaper than three-dimensional analysis because fewer cameras are needed and less sophisticated software needed for the analysis. Inaccuracy can occur if the segment being investigated rotates away from being perpendicular to camera. It can be useful, for example, to record the motion of a marker on the navicular to monitor motion in the sagittal plane or to monitor frontal plane motion of the calcaneus. However, the analysis of frontal plane motion of the calcaneus from a two-dimensional system may be problematic, due to range of motion of the rearfoot complex, the position of the assumed subtalar joint axis and out of plane may distort the true angle of motion.
METHODS OF ANALYSING GAIT
In three-dimensional analysis the computer tracks several sectors at once, allowing the observation of multiple joints and multiple segments in all three body planes simultaneously. Cardan angles are used to measure kinematics, by comparing orientation of a distal segment relative to a proximal segment. Linked segment models that are based on a joint being composed of two segments are used to describe the kinematics of gait. The foot can be modelled as many linked segments. Three measurable points on a segment are needed by the analysis software to determine the position and orientation of the body segments in all three body planes. The three markers are used to define directions within segments and build segmental coordinate systems in three dimensions. The joint centres are calculated using these segmental coordinate systems. From the joint centres, anatomically aligned coordinate systems are constructed and used to calculate joints angle during walking trials. To minimise errors, systems need to be calibrated prior to use. The placement of markers on the skin relative to osseous landmarks is crucial if models that have been developed for various systems are to be used with any reproducibility and if subjects are to be evaluated on different days or if different subjects are to be compared with each other. Movement of the skin marker over osseous landmarks also needs to be taken into account during the modelling of gait or the evaluation of an intervention. As well as calculating and providing graphs of kinematics, software computes the kinetic variables of the net joint moments, forces and powers based upon the kinematics and ground reaction force from the force platform. Electromagnetic tracking systems. These systems (e.g. Polhemusl''", Skill 'Iechnologies'P', Flock of Birds'[") are beginning to be used more frequently and are not dissimilar in the information they provide to the video-based gait analysis systems, but use electromagnetic sensors to track the motion of a 'marker' attached to the skin in three dimensions. They avoid the need for cameras and the use of multiple markers on each segment.
315
Electromyography (EMG) The EMG is the electrical signal associated with muscular contraction. EMG analysis can provide information about timing and intensity of muscle contraction. Such information provides data that indicate whether muscles are contracting in the correct order (phasic), at the right time and in an appropriate way. From this phasic muscle activity, tone, continuous and clonic muscle contraction or no muscle activity can be recorded. Data can assist with the assessment and aetiology of movement abnormality or in the review and assessment of physical therapies, rehabilitation or surgical interventions. ~lectromyographic data can be collected by usmg surface or indwelling electrodes. Indwelling electrodes are more definitive than surface electrodes in terms of sampling activity from a particular muscle. These electrodes are also required for analysis of deep muscle activity, e.g. in the deep posterior compartment of the calf. A major problem with this sort of electrode is that it causes intramuscular bleeding and may displace during muscle contraction (Kadaba et al 1985). The use of surface electrodes is clinically more viable as they are non-invasive and less variable than indwelling electrodes. These electrodes are generally used to provide gross informa.tion about the activity of muscle groups (Wmter 1990) and are therefore less selective. There is also an increased risk of 'crosstalk' - picking up activity from other muscles that are not directly under investigation. The EMG is therefore commonly used to identify gross phasic muscle activity prior to the fitting of orthoses designed to affect muscle activity, or for preoperative planning prior to tendon transfer or lengthening. For routine clinical practice the system is of little value.
Energy expenditure Patients who exhibit gross changes in their gait are likely to use more energy than patients with an efficient gait pattern. This is not surprising since the structure and function of the locomo-
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tor system is designed to be energy-efficient in terms of its ability both to store and use energy (Ch. 8). The determination of energy expenditure in gait has been undertaken since the 1950s. Many investigations have looked at normal and abnormal gaits in terms of energy cost. Estimation of the energy cost of walking usually involves the measurement of oxygen consumption (Inman et a11981) or calculation of potential and kinetic energy levels of body segments from their motions and masses (Quanbury et aI1975). A commercially available device called Caltrac measures the total number of calories used by subjects during walking. An alternative approach is to monitor heart rates as an indication of energy expenditure during activity (Rose et aI1989). In this method the 'physiological cost index' (PCl) is calculated as an estimate of energy used. The following formula is used: PCI = (heart rate walking - heart rate resting) / velocity where heart rate is in beats/min and velocity is in m/min, or beats and velocity are per second. This is probably more useful in clinical practice than the measurement of oxygen consumption and carbon dioxide production during activity. The measurement of oxygen consumption requires an analysis of the subject's exhaled air. Normally this requires the use of a Douglas bag, which allows the respiratory quotient to be calculated. Exercise is generally undertaken on a treadmill. Since the equipment required is bulky,
this sort of assessment is not routinely undertaken in the clinic.
Multisystems Several developments are currently under way to provide multiple linked data. These systems may well provide data from energy consumption studies with gait and force plate studies. In some gait laboratories additional information from EMG is also simultaneously presented. The difficulty with these systems is that they tend to cause information overload of the practitioner.
SUMMARY Gait analysis is a complex task. The collection and analysis of quantitative data can aid observation of gait. One of the main problems with these methods is the difficulty in establishing what is normal. Gait may alter with every step a person takes; as a result, repeatability is a major problem. The practitioner must also be wary of highly technical equipment which will provide complex data that prove difficult to interpret and require considerable computer power or time. In the research field, quantitative analysis of gait is making a contribution to our understanding of the complexities of gait. In particular, research into gait is improving our knowledge of its components and is also being used to design and evaluate therapeutic interventions.
REFERENCES Bauman J H, Brand P W 1963 Measurement of pressure between foot and shoe. Lancet 3: 629-632 Betts R P, Duckworth T 1978 A device for measuring plantar pressures under the sole of the foot. Engineering in Medicine 7(4): 223-228 Betts R P, Franks C 1, Duckworth T, Burke J 1980a Static and dynamic foot pressure measurements in clinical orthopaedics. Journal of Medical and Biological Computing 18: 674-684 Betts R P, Franks C I, Duckworth T 1980b Analysis of pressure and load under the foot. Part 2: Quantitation of the dynamic distribution. Clinical Physical Physiological Measurement 1(2): 113-124
Chao E Y S 1980 Justification of triaxial goniometer for the measurement of joint rotation. Journal of Biomechanics 13: 989-1006 Chodera J 1960 Pedobarograph: apparatus for visual display of pressures between contacting surfaces of irregular shape. C25 Patent, 104 514 30d Collins J J, Whittle M W 1989 Impulsive forces during walking and their clinical implications. Clinical Biomechanics 4: 179-187 Duckworth T, Boulton A J M, Betts R P, Franks C 1, Ward J D 1985 Plantar pressure measurements and the prevention of ulceration in the diabetic foot. Anatomical Record 59:481-490
METHODS OF ANALYSING GAIT
Eastlock M E, Arvidson J, Snyder-Mackler L, Danoff J V, McGarvey C L 1991 Inter-rater reliability of videotaped observational gait analysis assessments. Physical Therapy 71:465-472 Gage J R, Ounpuu S 1989 Gait analysis in clinical practice. Seminar in Orthopaedics 4(2): 72-87 Goodkin R, Diller L 1973 Reliability among physical therapists in diagnosis and treatment of gait deviations in hemiplegics. Perception and Motor Skills 37: 727-732 Harris R I, Beath T 1947 Army foot survey. An investigation of foot ailments in Canadian soldiers. Ottawa National Research Council, Canada NRC no. 1574 Henry A P J, Waugh W 1975 The use of footprints in assessing the results of operations for hallux valgus. A comparison of Keller's operation and arthrodesis. Journal of Bone and Joint Surgery 57B(4): 478-481 Hughes J, Clark P, Klenerman L 1990 The importance of toes in walking. Journal of Bone and Joint Surgery 72B(2): 245-251 Inman V T, Ralston H J, Todd F 1981 Human walking. Williams & Wilkins, Baltimore, MD Johnson G R 1990 Measurement of shock acceleration during walking and running using the shock meter. Clinical Biomechanics 5: 47-50 Kadaba M P, Wootten M E, Gainey J, Cochran G V B 1985 Repeatability of phasic muscle activity: Performance of surface intramuscular wire electrodes in gait analysis. Journal of Orthopaedic Research 3(3): 350-359 Keenan A M, Bach T M 1996 Video assessment of rearfoot movements during walking - a reliability study. Archives of Physical Medicine and Rehabilitation 77: 651-655 Kilmartin T E, Wallace W A 1992 The significance of pes planus in juvenile hallux valgus. Foot and Ankle 13(2): 53-56 Kippen S C 1993 A preliminary assessment of recording the physical dimensions of an inked footprint. Journal of British Podiatric Medicine 48(5): 74-80 Krebs D E, Edlestein J E, Fishman S 1985 Reliability of observational kinematic gait analysis. Physical Therapy 65: 1027-1033 Lereim P, Serek-Hanssen F 1973 A method of recording plantar pressure distribution under the sole of the foot. Bulletin of Prosthetics Research: 118-125 Lord M 1981 Foot pressure measurement: A review of methodology. Journal of Biomedical Engineering 3(2): 91-99 Minns R J, Craxford A D 1984 Pressure under the forefoot in rheumatoid arthritis; a comparison of static and dynamic methods of assessment. Clinical Orthopaedic and Related Research 187: 235-242 Miyasaki S, Iwakura H 1978 Foot-force measuring device for clinical assessment of pathological gait. Medical Biological Engineering and Computing 16: 429-436 Morris J R W 1973 Accelerometry: a technique for the measurement of human body movements. Journal of Biomechanics 6: 729-736 Muybridge, Eadweard 1955 The human figure in motion. Dover Publications, New York
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Nicol K, Henning E M 1978 Measurement of pressure distribution by means of a flexible large surface mat. In: Asmussen E, Jorgenson K (eds) Biomechanics VI-A. University Park Press, Baltimore, pp 374-380 Pathokinesiology Service and Physical Therapy Department 1993 Observational gait analysis handbook. Rancho Los Amigos Medical Centre, Downy, California Perry J 1992 Gait analysis: normal and pathologic function. Slack, Thorofare, New Jersey Quanbury AD, Winter D A, Reimer G D 1975 Instantaneous power and power flow in body segments during walking. Journal of Medical Engineering and Technology 7: 273-279 Rose J, Gamble J G 1993 Human walking, 2nd edn. Williams & Wilkins, Baltimore, MD Rose G K, Welton E A, Marshall T 1985 The diagnosis of flat foot in the child. Journal of Bone and Joint Surgery 67B: 1 Rose J R, Gamble J G, Medeiros Jet al1989 Energy cost of walking in normal children and those with cerebral palsy: comparison of heart rate and oxygen uptake. Journal of Pediatric Orthopedics 9: 276-279 Rose N E, Feiwell L A, Cracchiolo A 1992 A method for measuring foot pressures using a high resolution, computerized insole sensor: the effect of heel wedges on plantar pressure distribution and centre of force. Foot and Ankle 13(5): 263-270 Saleh M, Murdoch G 1985 In defence of gait analysis. Journal of Bone and Joint Surgery 67B: 237-241 Schwartz R P, Heath A L 1947 The definition of human locomotion on the basis of measurement. Journal of Bone and Joint Surgery 29(1): 203-214 Silvino N, Evanski P M, Waugh T R 1980 The Harris and Beath mat: diagnostic validity and clinical use. Clinical Orthopaedics and Related Research 151: 265-269 Southerland C C 1996 Gait evaluation in clinical biomechanics. In: Vamassy R (ed) Clinical biomechanics of the lower extremity. Mosby, St Louis Sutherland D H, Hagy J L 1972 Measurement of gait movements from motion picture film. Journal of Bone and Joint Surgery 54: 787-797 Tollafield D R 1990 A reusable transducer system for measuring foot pressures. A study of reliability in a commercial pressure pad. BSc thesis, Department of Health Sciences, Coventry Polytechnic Welton E A 1992 The Harris and Beath footprint: interpretation and clinical value. Foot and Ankle 13(8): 462-468 West PM 1987 The clinical use of the Harris and Beath footprinting mat in assessing plantar pressures. Chiropodist 42(9): 337-348 Wilkinson M, Menz H 1997 Measurement of gait parameters from footprints: a reliability study. The Foot 7: 19-23 Winter D A 1990 Biomechanics and motor control of normal human movement, 2nd edn. John Wiley & Sons, New York Young M J, Murray H J, Veves A, Boulton A J M 1993 A comparison of the Musgrave Footprint and optical pedobarograph systems for measuring dynamic foot pressures in diabetic patients. Foot 3(2): 62-64
CHAPTER CONTENTS
Introduction
319
Microbiology 320 Indicationsfor microbiology 320 Sampling techniques 320 Identification of microorganisms 325 Urinalysis 328 Indications for urinalysis 328 Collection of the urine specimen 328 Clinical assessment 328 Laboratory assessment 330
Laboratory tests A. Percivall 1. Reilly
Bloodanalysis 331 Indicationsfor blood analysis 331 Collection of the blood sample 332 Haematology 332 Biochemistry 334 Serology 335 Histology 335 Indicationsfor histology 335 Sampling techniques 336 Transportation and storage 337 Tests and interpretation of results 338
Summary
338
INTRODUCTION This chapter provides an overview of laboratory tests which can be performed on tissue and fluid samples from the lower limb. The tests of most relevance are: • microbiology • urinalysis • blood analysis - haematology, biochemistry and serology • histology. The tests playa vital role in enabling the practitioner to understand the nature of local and systemic related pathologies affecting the lower limb. Data from the tests can be used to: • provide information to aid the diagnostic process • enable a definitive diagnosis to be made in situations where there may be a number of possible diagnoses • measure the disease process in relation to normal parameters • reveal occult disease processes that might affect therapeutic and treatment options • enable implementation of effective treatment. The accuracy of any laboratory test is determined by its sensitivity, specificity, predictive value and efficiency (see Ch. 2). Sensitivity indicates how often a positive test result is obtained from a patient with a particular disease, whereas specificity indicates the number of negative results from patients without a particular 319
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LABORATORY AND HOSPITAL INVESTIGATIONS ----_._.__._--------- - - _ .
disease. Predictive values of positive test results give a measure of the frequency of the disease amongst all patients who test positive for that disease. The efficiency of a test indicates the percentage of patients correctly diagnosed with a particular pathology. Some of the tests can be undertaken in the clinic (near patient testing) but most require the use of laboratory services. Because of the expense and possible inconvenience caused by some of the tests it is important that they are only used where appropriate.
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caused by bacteria. Some viral infections of the foot do occur: the main protagonist is the human papilloma virus (HPV), which gives rise to plantar warts or verrucae. As with other forms of laboratory testing, microbiological testing should only be considered when it is likely to serve a useful purpose. The circumstances where it is applicable are: • when the results of testing are likely to influence the choice of treatment and result in more effective treatment for the patient • if the results will help identify sources of infection that need to be traced.
MICROBIOLOGY Indications for microbiology
Sampling techniques
Practitioners often request microbiological analysis to determine which particular organism is causing an obvious infection. However, the process can often be wasteful of both time and resources. Organisms found and identified in the laboratory usually fall into two categories: they either reflect the normal microbial flora or they fall outside this group and may be considered pathogens. It must be remembered that some normally resident organisms have the propensity to cause disease when found in abnormal sites. Conversely, just because a normal resident organism has been isolated at an abnormal site, it may not be the causative agent of the disease as commensals often contaminate samples sent to the laboratory. Further, the distinction between a pathogenic organism and a non-pathogen is often imprecise, e.g. where a person is a 'carrier' of a disease. This has led to the adoption of two basic rules:
Specimen types
• Never without good reason dismiss a microbe as a contaminant because it is not an 'accepted' pathogen. • Never without good reason accept a microbe as the necessary cause of a disease merely because it is an 'accepted' pathogen. Microorganisms are classified, biologically, into four main groups: viruses, protozoa, bacteria and fungi. In podiatry, with the exception of some superficial mycoses, most infections are
Specimens may be divided into two groups: those from normally sterile sites and those containing a normal resident flora. The differentiation is important since samples taken from normally sterile sites need to be inoculated into enrichment media. The media provides nutrients that will allow rapid growth (or amplification) of the organisms so that enough will be available for identification. Specimens taken from sites which have resident flora will, in contrast, need to be inoculated into media containing selective agents which will suppress the growth of any commensal organisms that might mask a potential pathogen. Ideally, when microbiological information is needed, an appropriate specimen is taken from the correct site. The specimen is transported immediately to the laboratory where it is processed quickly using the best tests, which are then correctly reported; these results are returned to the originator where they can be properly interpreted at a time when the information is relevant. Thus, it is important that the results of the work done in the laboratory are a true reflection of that specimen. Reasons for failure to report an organism originally present in a specimen include: • a delay in examination • the amount of specimen examined is insufficient
LABORATORY TESTS 321
• the amount of medium into which the specimen is inoculated is insufficient • the medium used for inoculation is of doubtful quality or unsuitable for the growth of the organism present • the incubation time of the inoculated medium is too short or the wrong conditions are provided • too few colonies are examined or the organism is not recognised. It is imperative to use reputable laboratories that employ strict internal standards and where reagents and media are performance-tested using standard organisms. If this procedure is adhered to, failure to report pathogens often rests with the sampling technique employed by the requesting practitioner. Good-quality specimens are obtained following certain guidelines: • The sample should be taken from the actual site where an infection has been diagnosed or is suspected. • Skin should not be cleaned with an antiseptic prior to taking the sample. • Strict aseptic technique must be followed in order to reduce the risk of the sample becoming contaminated by the microbiological flora of either the patient or the person taking the sample. • Many pathogenic microorganisms are surprisingly delicate. Unless special measures are taken they do not survive for long away from the body. This means it is often vital that specimens are transported to the laboratory without delay. • If some delay in transporting specimens to the laboratory is anticipated, it is important that steps are taken to prevent significant growth of contaminating normal flora organisms. These organisms grow at room temperature and can swamp the genuine pathogen. Suppression is normally achieved by refrigeration of samples or inclusion of an inhibitor in the transport medium. • It is important that sufficient sample is supplied so that the laboratory may use different methods for culture and analysis of the sample and thereby maximise their
•
•
•
•
•
•
chances of providing meaningful results. Many techniques may not work reliably if insufficient material is provided. If at all possible, samples should be taken prior to the commencement of antibiotic therapy. A drug may suppress a pathogen sufficiently to thwart isolation and identification, without actually working well enough to allow the patient to recover. It is often desirable for practitioners to wait for the initial results from the laboratory before starting antibiotic therapy. The results will allow practitioners to choose a narrowspectrum drug that they can be confident will do the job. However, if a life-threatening infection is suspected, a broad-spectrum antibiotic should be prescribed without delay. Specimens taken for microbiological analysis are by their very nature likely to contain pathogenic organisms and therefore should be treated with care. Good documentation is vital to ensure that samples are not mixed up, lost or subjected to inappropriate tests. It is vital that there is dialogue between the practitioner taking the sample and the laboratory staff. For more unusual organisms the microbiologist may be able to provide advice about the most appropriate methods of sampling and transportation. In order to be effective the laboratory requires good clinical information about the patient. The site of the suspected infection must be stated. The symptoms should be included on the clinical history section. Is there anything in the patient's history or in the clinical features (colour of pus, cellulitis) that might provide a clue as to the type of organism that is causing the problem? It is important to note recent treatment with antibiotics for the reason given above. Without this sort of detailed information, valuable time and resources may be wasted in inappropriate analyses.
Apparatus for obtaining specimens Containers. Strong leak-proof sterile containers of adequate size, conforming to the relevant
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LABORATORY AND HOSPITAL INVESTIGATIONS
British Standards specification, must be used to transport specimens from source to laboratory. These British Standards pay attention to minimising the health hazard from leakage, aerosol formation or spread of airborne particles when opening containers holding specimens. Containers range from 6 ml 'bijou' bottles, with screw caps suitable for body fluids, transport media and biological cultures, to large 300 ml bottles suitable for early morning urine samples and sanitary specimens. Whatever container is used, it must be clearly labelled in indelible ink with sufficient space for name, address, date and nature of specimen together with the time the specimen was taken. The label should have a water-resistant back. Swabs. Bacteriological swabs are often made from a pledget of Dacron (Terylene) attached to the end of a holder made from wood, plastic or metal, the whole of which is sterilised before use. Cotton wool pledgets can be used, but they may release lipoproteins, which can harm some fastidious bacteria. Swabs are the collection instrument of choice where microbial contamination or infection is suspected. Swabs complete and ready sterilised with or without transport media are available commercially. Collection of samples Wounds and mucosal surfaces. If a large quantity of pus is present this may be drained and sent to the laboratory; otherwise, a swab should be taken. Great care should be taken to avoid contamination with the normal flora from surrounding healthy tissue. It is important that a sample is taken from the base of the wound. If it is taken from the superficial edges, the flora of the adjacent skin could contaminate it. Swabs are placed into tubes containing a semi-solid transport medium, which prevents them from drying out. Skin. For mycological (fungal) investigations, nail clippings or skin scrapings from the edge of the lesion, taken with a blunt scalpel, can be placed in either a purpose-designed packet which has a black inner surface to help identify the sample, or a clean, dry plastic container.
Once the sample has been obtained it should be sent directly to the laboratory. Accompanying the sample will be a laboratory request form. Accurate information will enable the laboratory staff to carry out the most appropriate tests and investigations quickly and thus provide the clinician with the results without delay. Laboratory request forms vary, but it is important that the following information is included: • The patient's name. • The ward name or place where the sample was taken. • The patient's date of birth - resident flora change with age and it is therefore helpful to the laboratory staff in their investigations. • Date of admission to hospital - useful for infection control staff to monitor nosocomial infection. • Site of infection - be as specific as possible, it will help laboratory staff distinguish commensals from pathogenic flora. • Antibiotic therapy - even small amounts of antibiotic inhibit the growth of microorganisms in the laboratory. • Date and time of collection of the specimen microorganisms survive or multiply at varying rates and, thus, this information is important when the sample is cultured. • Specimen type and investigation requested remember most swabs look the same once in the laboratory, therefore state clearly what the specimen is. State whether the sample is for microculture and sensitivity, for virology or serology. • Biohazard status - if suspected, then the sample should not only be marked as such but should be transported in double-wrapped specimen bags. Laboratory examination
When samples containing suspected bacterial or fungal pathogens are sent to the laboratory, the most appropriate methods for investigation will be carried out. The methods used fall into the following categories:
LABORATORY TESTS
323
------------------------------------------------------
• direct examination - macroscopy and microscopy • culture • biochemical tests • sensitivity testing • serology and antigen testing • pathogenicity testing in animals. Macroscopy. Direct examination of the sample may give clues to the presence of infection or other factors. Turbid cerebrospinal fluid or the presence of pus in urine is immediate evidence of infection. The foul smell of anaerobic organisms may be detected in pus. Macroscopy will also show if there has been any contamination of the specimen: e.g. if the swab smells of disinfectant, rendering the sample useless. Most specimens will, however, need to be examined under a microscope. Microscopy. Although it is possible to examine specimens directly as an unstained preparation, more information can be obtained by staining the organisms present. However, there are often only a few organisms present and although these can be concentrated in some samples by, for example, centrifuging cerebrospinal fluid, it is usual to stain organisms obtained after culture. The use of microscopy on non-cultured specimens is most valuable when the sample has been obtained from a normally sterile site and thus the presence of any organism indicates infection. The most widely used stain is Gram's stain: gentian violet in Gram's stain binds to the cell wall of Gram-positive organisms and resists decolorisation with methanol or acetone. Those cells decolorised and stained with a counterstain, to make them visible, are classified as Gram-negative bacteria. The Gram stain immediately separates most bacteria into two groups and this together with other factors significantly aids diagnosis (Fig. 13.1). The other most commonly used stain is the Ziehl-Neelsen stain for acid-fast bacteria such as Mycobacterium spp. Staining and subsequent microscopy can be rapidly done and is often more valuable than culture - it can take up to 8 weeks to give a culture result in mycobacterial disease - to give a presumptive diagnosis of potentially life-threat-
ening diseases. Other microscopic techniques such as dark ground, immunofluorescence and electron microscopy are available and are used in specific cases, the latter being especially useful for viruses. Fungal hyphae and spores can often be seen under the light microscope: skin scrapings with suspected dermatophyte infection are mounted on a slide, cleared with 10% potassium hydroxide and stained with lactophenol blue. This simple procedure can often be done by the podiatrist without recourse to the laboratory, thus giving an instant diagnosis. Culture of these specimens can take 2-3 weeks. Many patients will have been prescribed a topical antifungal medicament based on the clinical features of the disease which, if caused by a dermatophyte, should be well on the way to resolution by the time the results are reported. Culture. Culture allows either the amplification of organisms initially present only in small numbers or selection of organisms from mixed inocula. Media for cultivation of bacteria and fungi must be capable of satisfying all their nutritional requirements and provide appropriate conditions which satisfy any factors which may affect their metabolism such as temperature, pH, osmolarity, oxygen, carbon dioxide and radiation. Culture media fall into the following classes: • Synthetic or defined media - prepared entirely from organic or inorganic chemicals such that the exact composition is known and is repeatable on any occasion. • Routine media - prepared from a mixture of digested or extracted animal or plant protein, such as beef or soya bean. They are usually supplemented with accessory growth factors and the pH adjusted to 7.4. They are used for routine growth of many bacteria and their composition is only approximately known. • Enrichment media - usually routine media with specific additions such as whole blood, serum or additional sugars, for the growth of more exacting organisms. • Selective media - routine media to which has been added selectively inhibitory chemicals
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LABORATORY AND HOSPITAL INVESTIGATIONS
A
CHAINS/PAIRS - - - ...
Streptococcus
NON-SPORING - - - ...
Propionibacterium
- - - - - - - - - - ... Escherichia
B
Figure 13.1
I:...:..:.':':"':':=':"=-=.'-=-'
-
Bacteria classified by staining, shape and use of oxygen
that suppress or kill all but a few types of (known) organisms. • Indicator media - routine media with the addition of substances which change the appearance of the media when a particular organism grows on it: for example, haemolysis of red blood cells by haemolytic
-
-
-
-
-
- - ...
Pseudomonas
Klebsiella
Vibrio
Proteus
Campylobacter
Salmonella
Haemophilus
Shigella
Brucella
Bacteroides
A. Gram-positive
B. Gram-negative.
bacteria or the production of coloration in dermatophyte test medium which incorporates an indicator that detects the rise in pH as the culture grows. Culture media can be used in either of two forms: liquid or solid. The solid form is prepared
LABORATORY TESTS
from liquid media with the addition of agar in concentrations of 1-4%. Liquid media or 'broths' are used, for instance, in the routine culture of pure cultures, sterility testing and anaerobic culture but suffer from the disadvantage that mixed cultures cannot be separated. The use of solid media facilitates this process and mixed cultures can be separated to allow isolation of individual colonies.
Identification of microorganisms Bacteria It is first necessary to isolate the microorganism in pure culture before carrying out identification tests. This is usually achieved by streaking or spreading the initial inoculum on the surface of solid selective media to produce isolated colonies of the desired organism. A colony is then selected and may need subculturing in routine or enriched media to restore normal growth before examination. Table 13.1 lists the types of bacterial pathogens found in the lower limb. The process of identification is normally done in the following way: Morphology. Stained microscopic mounts are examined for size, shape, cell aggregates, the
Table 13.1
325
presence of spores, etc. Hanging drop mounts of living organisms are examined for motility and special techniques can be applied for the examination of capsules and £lagellae. Staining reaction. The Gram stain is the most important of the staining reactions and, in conjunction with the morphology, is often enough to narrow the field considerably. Staining with malachite green will show the bacterial spores in Bacillus and Clostridium spp., the position of which in the cell can determine the species. Cultural characteristics. The size, shape and colour of colonies on solid media are sometimes helpful in diagnosis but are not sufficiently stable enough to be of routine value. However, the ability of an organism to grow on different media, including the stimulatory effects of added substances such as glucose, whole blood or serum, can be significant, i.e. the degree of haemolysis of blood incorporated into the media is used to differentiate streptococci. Alphahaemolytic streptococci such as Streptococcus pneumoniae produce colonies which are surrounded by a green ring, whereas Streptococcus pyogenes, a beta-haemolytic bacterium that is responsible for human throat infections, grows
Bacterial pathogens found in infections of the lower limb
Bacteria
Features
Staphylococcus aureus
Gram-positive, aerobic coccus. Most frequent cause of foot infections. Able to form an enzyme which coagulates citrated plasma: therefore the infection tends to remain localised. Responsible for boils, carbuncles, septic toes and osteomyelitis.
Steptococcus pyogenes
Gram-positive, aerobic or anaerobic coccus. All strains are beta-haemolytic. Produce enzymes which help break down surrounding connective tissue and thus aid its spread. May lead to cellulitis, lymphangitis and lymphadenitis and may be the prime organism responsible for necrotising fasciitis.
Pseudomonas aeruginosa
Gram-negative, aerobic bacillus. Gives rise to blue-green pus and produces a pungent odour. May be found in paronychia alongside Candida albicans.
Escherichia coli
Gram-negative, aerobic bacillus usually found in the gut. May be present in mixed infections and also is found alongside Candida albicans in paronychia.
Klebsiella spp.
Gram-negative, aerobic bacillus found in the gut. May be present in mixed wound infections.
Proteus spp.
Gram-negative, aerobic bacillus found in the gut. May be present in mixed wound infections.
Corynebacterium minutissimum
Gram-positive, aerobic bacillus responsible for erythrasma and pitted keratolysis.
Clostridium welchii
Gram-positive, anaerobic bacillus responsible for gas gangrene.
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LABORATORY AND HOSPITAL INVESTIGATIONS
with a clear ring around it where the blood cells have been completely lysed. These characteristics of colony growth of bacteria are accompanied by observations of the optimum temperature and pH ranges for growth and any pigment that may be produced. The gaseous requirements of organisms can also be diagnostic. Some bacteria are obligate aerobes (e.g, Bordeiella), but others (e.g. Pseudomonas aeruginoeai, which usually utilise molecular oxygen, are capable of utilising nitrate if cultured anaerobically. Anaerobes are either facultative, i.e. they can grow either aerobically or anaerobically, or obligate. Other factors such as the ability to grow in the presence of antibiotics, bile salts and high salt concentration should also be noted. Biochemical reactions. The ability of organisms to utilise particular substrates with a detectable end product, such as sugars, is a widely tested function. A range of these biochemical tests are available, including fermentation patterns, catalase, oxidase and nitrate production, and are, perhaps, the most useful aids to identification. For example, if a positive identification of Gram-positive cocci has been made, a catalase test can be done to aid further diagnosis. Staphylococci and streptococci are both commonly found cocci. Staphylococci are catalase-positive and are able to produce bubbles of oxygen when incubated with hydrogen peroxide. Streptococci, which are catalasenegative, do not react in this way and no oxygen is produced. This may help identify, say, a colony of staphylococci but does not help with identification of the species within the genus. A mannitol fermentation test may be able to determine if the colony consists of Staphylococcus aureus or Staph. epidermidis, since Staph. aureus tests positive, whereas Staph. epidermidis does not. Ready-made kits for multiple biochemical analyses are freely available commercially to enable complex tests to be carried out simultaneously with remarkable accuracy. All help to build a pattern of the metabolic activity of the organism, which - together with the information gained from microscopic and cultural examination - may be sufficient to identify the organism.
Sensitivity testing. Once the identification of an organism has been made, the susceptibility of the organism is often predictable. However, not all organisms have predictable resistance patterns and, thus, testing for sensitivity to particular antibiotics is required. Perhaps the most common method used to test antibiotic sensitivity is disc diffusion. A Petri dish is inoculated to produce a lawn of the test organism and an antibiotic-impregnated disc containing a range of antibiotics at concentrations comparable with therapeutic plasma levels is placed on the surface of the lawn. Inhibition of growth around the disc indicates the organism is sensitive to the antibiotic. Although this test indicates sensitivity of the organism, it does not show the lowest concentration (minimum inhibitory concentration, MIC) at which the antibiotic will inhibit growth of the microorganism. Although a relationship between MIC and successful outcome of antimicrobial chemotherapy cannot be clearly established, it is considered the most useful guide to the efficacy of antimicrobial therapy. Several methods of obtaining the MIC are available, and recently commercial test strips of paper with antibiotic incorporated along its length in increasing concentration have simplified the test. These test strips are put on a lawn inoculum of the test organism and the point at which the growth meets the test strip corresponds to the MIC (Fig. 13.2). From these figures the minimum bactericidal concentration (MBC) can be determined; this is defined as the lowest concentration that prevents growth after subculture to an antibiotic-free medium. These figures are required where accuracy of dose is important, e.g. in treating the immunocompromised patient. Serological and bacteriophage testing. It is often possible to identify bacteria by determining their antigenic composition. This can be achieved by incorporating suspensions of the organism in a series of standardised solutions of purified antibodies. Where agglutination occurs, it can be inferred that the organism possesses a specific antigen against which that antibody was originally prepared. Bacteriophages are also highly
LABORATORY TESTS
327
--------_._------------------------------------------------
High
M.I.C 7'----- Low
Figure 13.2 E-test. An antibiotic strip placed on a lawn of test organism to show minimum inhibitory concentration (MIC).
specific in their lytic action of bacteria. Thus, stock preparations of known phages can be used in a similar way to antisera, allowing precise identification of variants within species, e.g. staphylococci. Animal tests. The identification of pathogenic organisms may require the use of animal inoculation but is only of value if the inoculum produces highly specific symptoms or lesions in the sensitive laboratory animal. Fungi
Fungal infection is a common manifestation in podiatric practice and is usually diagnosed on its Table 13.2
clinical manifestation. Where an infection is suspected, scrapings from the active periphery of a skin lesion or full-thickness clippings of nails together with subungual debris should be taken and inoculated on and into Sabouraud's agar, which is selective for fungal growth. The plates should be incubated at 25-28 QC. Colonies of Candida spp. often appear overnight or in a day or two; dermatophytes take 1-3 weeks to appear. Species identification depends on the rate of growth, colonial appearances and microscopic appearance of the fungus, in particular the fungal spores - both micro- and macroconidia. Sporulation of dermatophytes usually occurs within 5-10 days of inoculation. Table 13.2 lists the type of fungus responsible for fungal infections affecting the feet. Viruses
Unlike bacteria and fungi, viruses cannot be grown on artificial media and usually require tissue culture, chick embryo culture or inoculation into laboratory animals. Much work is in progress to simplify viral identification. The processes are complex and outside the scope of this chapter. Although newer techniques for the detection and identification of microorganisms, such as detection of antigens, antibodies and polymerase chain reaction studies, help in the overall armamentarium available to the practitioner, culture still remains the gold standard against which all these newer techniques are measured. The best
Fungi responsible for fungal infections of the feet
Fungus
Features
Trichophyton rubrum
Affects skin and nails. 85% of cases of onychomycosis thought to be due to T. rubrum. Can affect skin and hair in a number of ways. Diffuse dry scaling tinea on the soles is usually due to T. rubrum.
Trichophyton mentagrophytes
Affects skin and nails. Can cause a range of skin responses but is especially associated with vesicle eruption. 12% of cases of onychomycosis due to T. mentagrophytes.
Epidermophyton f1occosum
Affects skin in a variety of ways but is especially associated with vesicle eruption. Rarely causes onychomycosis.
Scopulariopsis brevicaulis
Secondary pathogen. Produces a dark green-black discoloration.
Candida spp.
A yeast of which Candida albicans is the most common. Affects skin and nails. In nails is often responsible for paronychia.
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LABORATORY AND HOSPITAL INVESTIGATIONS
non-culture tests have specificities and sensitivities in the order of only 85-90%, even in the hands of experienced staff. It should always be remembered that because of the skill and costs involved in culturing and carrying out the exacting tests to identify organisms, the practitioner must take care to ensure that correctly taken specimens are sent to the laboratory. This will help speed the result and thus allow appropriate, efficient and, more importantly, effective treatment to be delivered to the patient.
URINALYSIS The kidneys play an important role in the maintenance of homeostasis, one of their functions being the excretion of waste and foreign substances through the formation of urine. Water accounts for 95% of the total volume of urine; the remaining 5% consists of electrolytes, cellular metabolites and exogenous substances such as the excretion products of drugs. The amount of fluid drunk and the amount lost through perspiration, respiration and defecation modify the amount of urine produced. The average daily output of urine for an adult is 1200 ml. If a disease alters the body's metabolism or kidney function, traces of substances not normally present (or normal constituents in abnormal amounts) may appear in the urine. Many early disease states can be detected by urinalysis before they become clinically obvious and it therefore plays a useful role in the assessment of patients. Assessment of a patient's urine can be made both in the clinic and in the laboratory. Testing is non-invasive and cost-effective, and urine specimens are easily obtained. Clinical assessment is commonly performed, allowing the practitioner to obtain information about the health status of their patient rapidly.
consequences for the lower limb. Renal and hepatic diseases may have serious systemic repercussions, which complicate diagnosis and affect the treatment of lower limb problems. Urinalysis is particularly useful in the preoperative assessment of patients to screen for illnesses which may complicate or contraindicate elective procedures. Screening for a urinary tract infection (UTI) or the presence of bacteria in urine can also identify those patients at increased risk of developing postoperative wound infections.
Collection of the urine specimen Urine specimens can be classified as a firstvoided morning, random or timed sample. The first-voided morning specimen is the most concentrated of the day, and is the most specific for nitrates and proteins. The random specimen is the most convenient for patients to collect and is the most commonly used specimen. Timed specimens are combinations of urine voided over a specific length of time and are more applicable to the hospital environment. Proper collection and prompt examination of urine is important for accurate analysis. The use of clean collecting vessels will minimise bacterial and chemical contamination. The patient is usually asked to provide a midstream specimen of urine (MSU), which should be less than 4 hours old at the time of testing. To collect the specimen, the patient should be instructed to first gently cleanse the opening to their urethra with water and begin to urinate into the toilet, subsequently inserting a clean container into the urinary stream to collect the sample. The container is removed from the urine stream and the act of voiding completed.
Clinical assessment Physical examination of urine
Indications for urinalysis Urinalysis may be used as an aid in the diagnosis of renal disease, hepatic disease and diabetes mellitus, all of which have relevance to the podiatrist. Diabetes mellitus can have widespread
Colour. Urine should be examined under good lighting against a white background. Normally, the colour of urine is yellow owing to a pigment called urochrome. The colour becomes deeper with increasing concentration, such as in the first
LABORATORY TESTS
void of the morning. Other changes in colour are seen, often due to the ingestion of certain medications or food (Table 13.3). The patient may be concerned about any change in their urine. Ascertain the circumstances surrounding the patient noticing the change in colour. Did the colour only appear after the urine contacted the container? Did the urine have to sit in the sun for hours before the colour appeared? Clarity. The common terms used to describe urine are clear, hazy, cloudy, turbid or milky. Urine is normally clear. Suspended particles will give it a hazy or cloudy appearance. Turbid urine (Plate 27) can be caused by the presence of a UTI, leucocytes, erythrocytes or parasitic disease. Prostatic fluid, blood, lipids or sperm can cause milky urine. Odour. Freshly voided urine has little smell; stale urine may contain ammonium salts from the breakdown products of urea, producing an offensive odour. Infected urine has a foul smell; the odour worsens if the urine is left to stand. Ketones in the urine, ketonuria, produce a sweet pear-drop smell and suggest a ketoacidotic state that requires urgent medical attention.
Table 13.3
Causes of colour change in urine
Colour
Cause
Red
Haematuria Haemoglobinuria Anthrocyanin (in beetroot)
Orange-red
Rifampicin
Orange
Anthraquinones Dehydration
Yellow(++)
Bilirubin Riboflavin
Green
Biliverdin
Green-blue
Amitriptyline Resorcinol
Blue
Methylene blue
Brown
Urobilinogen Porphyria Metronidazole
Brown-black
Haemorrhage L-dopa Senna
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Reagent testing
A variety of dipsticks are available for testing urine. Some are single-test based, such as Clinistix'v which tests for glucose; some are multi-test based, such as Multistix" 8SG which has eight reagent strips (Plate 28). To use a multitest reagent, a reagent strip is taken from the bottle and completely immersed in the urine specimen. The strip is removed and excess urine wiped off on the rim of the specimen container. The strip is held horizontally (therefore not allowing chemicals to drip from one pad to another) and the colour of the test areas compared with the colour chart on the bottle, following the manufacturer's instructions as enclosed. Multi-test reagents test results: Glucose. Glucose is not normally detectable in the urine. The presence of glucose in the urine may be due to elevated blood glucose levels. (as in diabetes mellitus) or reduced renal absorption. A negative result is therefore normal. The test area will detect glucose at 7 mmol/l, and thus a positive result should be followed up with a blood glucose analysis to establish the cause of the glycosuria. The most common cause of glycosuria is diabetes mellitus. However, it is also seen with stress (as glycogen stores are mobilised from the liver) and secondary hyperglycaemia due to Cushing's syndrome, thyrotoxicosis or steroid use. Bilirubin. The presence of bilirubin in the urine is indicative of hepatic or biliary disease. A positive result should be followed up - even trace amounts of bilirubin are sufficiently abnormal to require further investigation. Ketones. Ketones (primarily acetone and acetoacetic acid) are breakdown products of fatty acid metabolism and are abnormal urinary constituents. Their presence may be due to starvation or uncontrolled diabetes mellitus. False positives are seen with certain medications such as metformin and insulin. A positive result in a diabetic patient requires urgent medical attention. Specific gravity. This parameter tests the concentrating and diluting power of the kidney. The specific gravity of urine is normally between 1.012 and 1.030 and increases with glycosuria,
330
LABORATORY AND HOSPITAL INVESTIGATIONS
proteinuria or infection. Decreased values are seen in diabetes insipidus, pyelonephritis and glomerulonephritis. A fixed value may indicate renal failure. Blood. Haematuria is the presence of red blood cells (RBCs) in the urine. In microscopic haematuria, the urine appears normal to the naked eye, but examination under a microscope shows a high number of RBCs. Gross haematuria can be seen with the naked eye. Most of the causes of haematuria are not serious: e.g. exercise may cause haematuria for 24 hours and blood is often found in the urine of menstruating females. However, the condition can be associated with serious renal or urological disease and/ or UTI. A positive result will require a medical opinion. pH. Normal urine is slightly acidic, with a pH of 5-6. Values are lowest after an overnight fast and highest after meals. Strongly acid urine may indicate starvation or uncontrolled diabetes mellitus. Recheck the glucose and ketone test results if this is the case. Very high (alkaline) values suggest infection and warrant further investigation. Protein. Normal urine contains small amounts of albumin and globulin, not normally detectable by the reagent strip. A negative result does not therefore rule out abnormal proteinuria. A positive result indicates renal disease, UTI or hypertension and requires confirmation. Urobilinogen. Although normally present in urine, elevated levels of urobilinogen indicate liver abnormalities or haemolytic anaemia. A positive result requires an urgent medical opinion. Nitrite. The presence of nitrites requires their conversion from nitrates by Gram-negative bacteria. A negative test does not rule out infection since Gram-positive cocci will not produce nitrites, and note that the urine must also be retained in the bladder for several hours to allow the reaction to take place. A positive result confirms a UTI and requires further analysis. Leucocytes. The presence of leucocytes and other components of pus in the urine, pyuria, is an indication of bladder or renal infection. A negative result where clinical symptoms are present would require microscopy and culture. A positive result
confirms a UTI and also requires further analysis to identify the infecting organism.
Laboratory assessment Microscopy
A small amount of the collected specimen is centrifuged at 5000 rpm for 5 minutes and the sediment resuspended in a few drops of urine and mounted on a glass slide:
• Erythrocytes: more than 5 erythrocytes per high power field is abnormal.
• Leucocytes: more than 5 leucocytes per high power field may indicate bacterial infection or renal disease. • Epithelial cells: derived from the cellular lining of the genitourinary (GU) tract, small numbers of epithelial cells may be found in urine. A large number is an abnormal finding. • Casts: casts result from the precipitation of protein, cells and debris inside the renal tubules. They are so named because their shape represents a 'cast' of the lumen of a tubule. Hyaline casts are formed from Tamm-Horsfal protein and may be found in normal patients but are more frequently seen in sufferers of hypertension, congestive heart failure or renal disease. Granular casts are composed of protein and tubular cells and indicate renal tubular disease. Red cell casts suggest disease associated with bleeding and white cell casts are an indicator of acute pyelonephritis. • Crystals: crystals may be found in patients with urinary stones but are found in the urine of normal patients as well. Formation of crystals varies with the pH; urate crystals can be found in acid urine and phosphate crystals can be found in alkaline urine. Cystine crystals are found in patients with cystinuria and oxalate crystals may be present in patients with oxalate stones. Culture
A urine culture is used to estimate the number of bacteria present in urine and to identify the
LABORATORY TESTS
exact organism present. Urine is an excellent culture medium and is easily contaminated from the GU tract. At room temperature, contaminants will grow rapidly unless the urine is plated or refrigerated promptly. Urine cultures are obtained from patients suspected of having a UTI, and should be collected taking extra care to follow the MSU method as described above. Cultures that demonstrate multiple organisms have usually been contaminated during collection.
BLOOD ANALYSIS Blood is the fluid component of the vascular system and constitutes about 8% of the total body weight - approximately 5-6 litres in an adult male and 4-5 litres in an adult female. It comprises plasma (55%), a watery liquid that contains dissolved substances, and formed elements (45%), which are cells and fragments (Table 13.4). The principal functions of blood are: • the transportation of heat, hormones and metabolites (such as oxygen) around the body • to help in the regulation of pH and temperature • to protect the body through clotting mechanisms, the action of white blood cells and antibodies. Table 13.4
Components of blood
Plasma (55% of blood)
Formed elements (45% of blood)
Water (91.5% of plasma) Solutes (8.5% of plasma) protein albumin globulin fibrinogen electrolytes respiratory gases enzymes hormones digestion products waste
Red blood cells (RBCs) White blood cells (WBCs) neutrophils (40-75%) lymphocytes (20-45%) monocytes (2-10%) eosinophils (1-6%) Platelets
331
Indications for blood analysis Blood tests can aid in the diagnosis of the following, all of which are relevant to the practitioner dealing with the lower limb: • anaemias, e.g. from an altered erythrocyte count • infections, e.g. from a raised leucocyte count • systemic inflammation, e.g. from a raised erythrocyte sedimentation rate (ESR) • metabolic disorders, e.g. raised serum glucose and ketone levels • clotting disorders, e.g. from an abnormal platelet count • hormonal disorders, e.g. from a high level of serum thyroxine • immunology-related disorders, e.g. in seropositive arthritides. The use of routine blood sampling in asymptomatic patients is questionable. Many studies of routine biochemical screening prior to surgery have revealed less than 1 % of abnormality in unsuspected cases. In cases where abnormality was detected, the results of the tests made no difference to the anaesthetic or surgical management of the patient. Blood screening can be useful in detecting certain haematological diseases such as sicklecell anaemia and thalassaemia. Both conditions can have implications for the management of lower limb problems, especially surgical management. When surgical intervention is planned it may be worthwhile to undertake a screening for these conditions in those at particular risk. Blood tests are also indicated for surgical patients with a history of thrombosis or clotting disorders. However, in general, patients without clinical signs of systemic disease are unlikely to produce grossly abnormal results. Significant liver disease, for example, is almost certain to produce jaundice. The appearance of bilirubin in the urine offers a cheap alternative screening test. Initial detection of diabetes can be reliably performed on a urine sample, which also has the benefit of revealing proteinuria and unrecognised renal impairment.
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LABORATORY AND HOSPITAL INVESTIGATIONS
Collection of the blood sample
Haematology
There are several ways in which blood samples may be obtained. An autolet with a disposable needle can be used to produce a small drop of blood from a pinprick. It is usual to prick the distal pulp of the thumb, and is the method by which diabetic patients perform daily monitoring of their blood sugar levels. For laboratory-based tests, a greater quantity of blood than that obtained from a pinprick is required. It is important that the person taking the sample has appropriate and current qualifications - a phlebotomist is a technician who has been trained to take samples of blood. Blood samples are taken from a vein, usually in the forearm, using a tourniquet above the elbow to force blood to accumulate in the vein. A needle is inserted into the vein and this needle fitted to a syringe or a vacutainer (an evacuated tube). To ensure appropriate stability of the sample, containers that contain an appropriate additive are used. Many samples must be prevented from clotting and therefore an anticoagulant is added. The anticoagulant of choice is the dipotassium salt of ethylenediamine tetra-acetic acid (EOTA). Where an infection is suspected, two or more samples may be taken. One type of container used to transport the blood sample facilitates testing for the presence of aerobic organisms; another type facilitates testing for the presence of anaerobic organisms. Whether you take the sample yourself or refer to a hospital it is essential you provide the laboratory undertaking the tests with relevant information. The patient's hospital number or laboratory number, if there have been previous tests, will enable current results to be compared with previous test results. Many laboratories produce cumulative results which give an indication of patient progress. Normal ranges vary in pregnancy; for this reason it is vital to provide this information on the request form. Blood can be analysed in a variety of ways. Analysis may focus on the cellular content (haematology), chemistry (biochemistry) or immunological aspects (serology) of blood.
Haematological investigation generally follows a sequence of diagnostic steps: • the full blood count • the blood film • inflammatory tests erythrocyte sedimentation rate (ESR) plasma viscosity C-reactive protein • clotting studies. The full blood count. A full blood count (Table 13.5) includes basic data on RBCs, white blood cells (WBCs), haemoglobin concentration and mean cell volume (MCV). In the laboratory, automated blood count machines perform the analysis. Table 13.5
Normal haematological values
Factor
Value
Haemoglobin Men Women
13.8 g/dl 11.5-16.5 g/dl
Erythrocytes: red cell count (RCC) Men Women Leucocytes: white cell count (WCC)
4.5-6.5 x 10 12/1 3.8-5.8 x 10 12/1 4.0-11.0 x 10 9/1
Mean cell volume (MCV)
78-98 II
Packed cell volume (PCV)/haematocrit Men Women Mean cell haemoglobin (MCH)
0.40-0.54% 0.35-0.47% 27-32 pg
Mean cell haemoglobin concentration (MCHC)
30-35 g/dl
Thrombocytes
150-400 x 10 9/1 10-100 x 10 9/1
Reticulocytes (adults) Differential WCC: neutrophil granulocytes lymphocytes monocytes eosinophil granulocytes basophil granulocytes Erythrocyte sedimentation rate (ESR)
2.5-7.5 x 109/1 1.0-3.5 x 10 9/1 0.2-0.8 x 10 9/1 0.04-0.4 x 109/1 0.01-0.1 x 109/1 <20 mrn/hour
«60 years 01 age) C-reactive protein (CRP)
811g/ml
Prothrombin time (PT)
11-13 seconds
Activated partial thromboplastin time (APTT)
27-36 seconds
Bleeding time
1-4 minutes
LABORATORY TESTS
• Normally, more than 99% of the formed elements are RBCs. The percentage of total blood volume occupied by the RBCs is called the packed cell volume (PCV) or haematocrit, expressed as the percentage of total blood volume packed by centrifuge in a given volume. The PCV is reduced in all types of anaemia; a haematocrit measurement of less than 30% is probably detrimental to surgical intervention. • The haemoglobin concentration reflects the oxygen-carrying capacity of the blood. It is reduced in all forms of anaemia and is increased in polycythaemia. • RBC indices are arithmetic ratios derived from the RBC count, PCV and haemoglobin concentration. The most useful of these ratios is the MCV, which is a measurement of the haematocrit divided by the RBC count. It is low, less than 82 fl, with microcytic anaemia and greater than 100 fl with megaloblastic anaemia. The mean cell haemoglobin (MCH) is the haemoglobin concentration divided by the RBC count; the mean cell haemoglobin concentration (MCHC) is the haemoglobin concentration divided by the PCv. • The WBC count can be decreased (leucopenia) or increased (leucocytosis). Leucopenia can result from a viral infection, ingestion of certain drugs (especially antineoplastics) and radiation. Leucocytosis can result from acute bacterial infection, leukaemia, acute haemorrhage and tissue necrosis. • The platelet count provides quantification of thrombocytopenia but gives no indication of platelet function. • The reticulocyte count measures those early forms of RBC with inclusion fragments of the endoplasmic reticulum. The count quantifies the rate of erythropoiesis: increased numbers of reticulocytes reflect increased formations of RBCs, as seen in haemorrhage or haemolysis; a low number suggests nutritional deficiency or leukaemia. The blood film. Details of individual blood cell types are obtained from microscopic examination
333
of a stained blood film. Many abnormalities in RBC morphology can be seen. Anisocytosis is excessive variation in the size of RBCs, poikilocytosis is excessive variation in their shape, spherocytosis demonstrates round RBCs, and the RBCs of sickle-cell disease are long and bent. The differential WBC count is a reflection of 100 WBCs that are morphologically examined in a peripheral smear. The numbers of different types of WBCs are expressed as a percentage of the whole (see Table 13.4). A left shift denotes a decrease in neutrophil segmentation, which is a sign of increased turnover and demand for WBCs most commonly seen in acute bacterial infections. Inflammatory tests
• ESR: the ESR is the rate of fall of RBCs in a
column of blood. The ESR increases with age and is higher in females than in males. A raised ESR reflects an increase in the plasma concentration of proteins and is indicative of diseases associated with malignancy, infections and inflammations. • Plasma viscosity is used by some laboratories instead of an ESR. As with the ESR, the level of viscosity is dependent on the concentration of proteins, but is the same in males and females, and increases only slightly with age. • C-reactive protein (CRP) is synthesised in the liver and can be detected in the blood within 6 hours of an inflammatory response. This test is also replacing the ESR. Clotting studies
• The prothrombin time (PT) determines the amount of prothrombin in the blood. Test reagents are added to a sample and the time taken for the blood to clot noted. It provides a laboratory measurement of the extrinsic blood coagulation pathway. The PT is prolonged by deficiencies in fibrinogen, prothrombin and factors V, VII and X but remains normal in patients with haemophilia A and B, or platelet deficiencies. It is commonly used to monitor patients taking warfarin.
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• The activated partial thromboplastin time (APTT) provides a laboratory measurement of the intrinsic blood coagulation pathway and is the best single screen for disorders of coagulation. The APTT is prolonged by deficiencies in fibrinogen, prothrombin and factors V, VIII, IX, X and XII, and in patients with haemophilia A and B, or platelet deficiencies. • The thrombin time (TT) measures the clotting (fibrin formation) time of a sample of blood following the addition of a small amount of thrombin. The most common cause of a prolonged TT is the presence of heparin. • The bleeding time is the time required for cessation of bleeding from a small skin puncture, usually of the ear lobe. As the droplets of blood escape, touching the wound with filter paper blots them. When paper no longer stains, the bleeding has stopped. It is a standard assay that measures the effectiveness of platelet plug formation. The bleeding time is increased if platelet function is abnormal, e.g. patients who are suspected of having a qualitative platelet disorder such as von Willebrand's disease or patients on aspirin therapy.
Biochemistry Arterial blood gas studies are the best single determination of lung function, referring to the determination of arterial oxygen and carbon dioxide tensions and the pH. Indications for blood gas studies include the assessment of preoperative lung function, documentation of pulmonary disease and continuing assessments of cardiopulmonary diseases. Serum chemistry assays useful in the diagnosis or monitoring of many metabolic, renal and fluid/ electrolyte abnormalities are given in the following paragraphs. Urea and creatinine are dependent on the kidney for excretion: therefore, their measurement is an index of renal function. Urea, an end product of protein metabolism, is synthesised in the liver, and is the principal nitroge-
nous constituent of urine. In pathologies that affect renal function, its serum concentration rises. Azotaemia is defined as increased nitrogenous substances in the blood and is characterised by a blood urea nitrogen (BUN) level greater than 20 mg/100 ml. The BUN: creatinine ratio is 10: 1 in normal individuals; in patients with acute renal failure both BUN and creatinine levels rise and the ratio may be unchanged. The BUN level alone is increased in patients with renal disease, gastrointestinal haemorrhage or increased protein metabolism. The BUN level is decreased in patients with severe cirrhosis, inadequate protein intake or in pregnancy. The concentration of creatinine in the serum has a linear relationship to glomerular filtration, making it a more sensitive indicator of renal disease than BUN. Creatinine levels rise in patients with renal disease, gigantism, acromegaly and increased dietary intake from roasted meats. The normal range for uric acid is 3.5-7.2 mg/ dl for males and 2.6-6.0 mg/ dl for females. Elevated serum uric acid is not a reliable diagnostic test for gout. However, acute gout never occurs in patients who have a serum uric acid level in the lower half of the normal range. The test can give rise to false negatives and positives. In the first few attacks, when it is often difficult to diagnose, the serum acid level is often below the higher level. Serum uric acid levels can be helpful in monitoring treatment. Sodium levels are increased in patients with dehydration, primary aldosteronism, Cushing's syndrome and with some diuretic drugs. Sodium levels are decreased in fluid retention (seen in congestive heart failure), with unreplaced body fluid loss (vomiting, diarrhoea) and in Addison's disease. Sodium is the principal cation of extracellular fluid. Potassium levels may be increased (>5.5 mmol/I) in patients with renal failure, mineralocorticoid deficiency, acidosis, massive tissue necrosis and with high-dose penicillin (hyperkalaemia). Hypokalaemia may occur in patients with chronic diarrhoea, primary/secondary aldosteronism, Cushing's syndrome or with diuretic drugs.
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-"--------"---------------The concentration of chloride tends to decrease along with sodium to maintain electrical charge equilibrium. Levels increase and decrease, as per sodium. The measurement of carbon dioxide provides a differential diagnosis in the change of blood pH, acidosis or alkalosis. The carbon dioxide level is higher in respiratory alkalosis (pulmonary emboli, asthma or liver disease), with metabolic acidosis (diabetic ketoacidosis), with decreased excretion of hydrogen ions (renal failure) and with increased loss of alkaline fluids (chronic diarrhoea). Blood glucose. Blood sugars bind non-enzymatically to proteins forming stable covalent linkages. The measurement of glycated derivatives of haemoglobin and plasma proteins has provided a reliable index of long-term blood glucose control in diabetics. In normal individuals a small percentage of the haemoglobin molecules in RBCs become glycosylated, i.e. chemically linked to glucose. Glycosylated haemoglobin (GHb) can be separated from normal HbA by electrophoresis into three fractions: HbA}A, HbA}B and HbA}C. Normally only HbA}C is quantitated, and gives a measure of mean blood sugar over the preceding 2 months. The percentage of glycosylation is proportional to time and to the concentration of blood glucose. Therefore, poorly controlled diabetics will have a greater percent of GHb. The glucometer uses a small sample of blood to test blood glucose levels. Glucometers vary slightly in design; all come with instructions for use. It is essential that the practitioner follows the manufacturers' guidelines, regularly cleans the equipment and takes care to calibrate the equipment prior to use. The glucometer gives the amount of glucose in the blood, in millimoles per litre, as a digital read-out. A normal reading is within the range of 4-8 mmol/l (nonfasting) and 3-5 mmol/l (fasting). Glucometers have been known to give false positive and negative readings. This is usually due to inadequate cleaning, poor calibration or not following the manufacturers' guidelines when carrying out the test.
Serology Conditions associated with unclear causes of joint pain in the foot and lower limb pose a concern for the practitioner, especially where the ankle, subtalar or metatarsophalangeal joints are involved. Seropositive arthritides can be a cause of this type of joint pain. Analysing serum for the presence of rheumatoid factor can be helpful in these instances. Rheumatoid factors are autoantibodies found in the serum, usually of the immunoglobulin M (IgM) class, which are directed against human IgG. Either the latex or Rose-Waaler tests can detect their presence. Their presence may indicate rheumatoid arthritis (in 80% of cases), systemic lupus erythematosus (in 50% of cases), systemic sclerosis (in 30% of cases), Sjogren's syndrome (in 90% of cases), polymyositis (in 50% of cases) or dermatomyositis (in 50% of cases).
HISTOLOGY Histopathology is the examination of tissues or cells for the presence or absence of changes in t~eir structure due to abnormal condition. It provides a useful method for clarifying or confirming a diagnosis and gives an insight into how a disease originates, progresses and is influenced by therapy. The preparation of thin slices or sections of the tissues, which are coloured differentially by the use of various stains, makes this study possible. Tissue and body fluids (other than blood and urine) can be removed from the lower limb for histological examination.
Indications for histology The indications for histological analysis are: • when a lesion does not have a clear clinical diagnosis and resists treatment, e.g. neuroma • when there is no exudate which can be cultured for the presence of pathogens; in this case, a sample of tissue is needed for microbiological purposes and for identification of cellular changes
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• where tissue has an abnormal appearance and malignancy is suspected • where the lesion fails to heal, e.g. inclusion cyst, pyogenic granuloma (Plate 29).
Table 13.6 Tissues which can be removed from the foot for histological analysis
Epithelial
Stratified cuboidal epithelium (sweat glands/secretory function)
Sampling techniques The range of tissues from the lower limb that can be removed for histological analysis can be found in Table 13.6. Various methods can be used to remove tissue or fluid for investigation. The technique used will depend upon the site and the amount that needs to be removed. A wide range of investigations can be performed on tissues taken from the body. Samples should be collected in such a way as to pre-empt the method to be used. The practitioner should therefore decide at the outset what investigations are required. Appropriate collection and storage techniques are vital to preserve the sample. Most techniques require local analgesia. In the case of tissue it is generally advisable to remove a section of surrounding healthy tissue as well as the abnormal tissue; this allows the pathologist to make comparisons between normal and abnormal tissue. Sources for histological diagnoses can be either tissue or cell preparations. Tissues can be obtained by biopsy (shave, punch, needle or excision), from resected organs (partial or complete) or via autopsy. Cell preparations include fluid aspirates, smears, brushings and fine needle aspirates. In podiatric practice it is primarily tissues that are sampled and sent to histopathology. Some examples of biopsy are given below.
Multicellular exocrine glands: - coiled tubular eccrine and apocrine (sweat) - branched acinar holocrine (sebaceous) Connective
Mesenchymal found in adult tissue below skin and blood vessels Loose areolar: subcutaneous layer of skin and blood vessels, nerves associated with fibroblasts, macrophages, mast cells and various fibres Adipose: under weightbearing surfaces, joints and bone marrow Dense collagenous: common to fascia, aponeuroses, tendons, ligaments Elastic and reticular: less abundant in feet Hyaline and fibrocartilage: chondrocytic cells associated with joints, especially distal metatarsal ends, fibrocartilage submetatarsals, between bones and tendons Osseous (bone): made of compact (outer), cancellous (inner) and cellular components associated with regeneration
Muscle
Skeletal: striated, contractile form attached between bones; mainly intrinsic form in feet in four layers
Nerve
Cell body and axons Neuroglia: found at sites of tumours
Synovial membranes
Loose connective tissue: line structures and secrete synovial fluid, tendon lining, bursae, do not contain epithelial cells
Tissue repair
Stroma: supporting connective tissue restoration; active repair or scar tissue due to fibroblasts or keloid (overactivity)
Biopsy Shave. A shave biopsy can be achieved by introducing an endoscope into the body. This procedure is used when it is necessary to remove a piece of tissue from a deep structure, e.g. synovial membrane from a joint. Punch. A punch biopsy (incisional biopsy) involves the removal of a small section of abnormal tissue. The procedure is not as extensive as excisional biopsy but is still open to complica-
Keratinised stratified epithelial tissue (skin)
Scab/fibrin plug: sealing wound Granuloma: active repair tissue
tions such as deep infection. A punch, which consists of a cylinder with a sharp, fine cutting edge,
LABORATORY TESTS 337
is used. The punch is pushed through epithelial tissue and a small section of epithelial and/or connective tissue is removed. A trephine is a similar instrument to a punch, but much more sturdy. It is used for punching holes in bone. In these cases a larger access hole is necessary. Bone samples should, wherever possible, have clear radiographs attached to assist the determination of the general appearance of the lesion. The advantage of punch biopsy lies in the small area of tissue removed. Normal tissue is not usually included. The depth of tissue sampling will depend upon the pressure applied. Punch biopsy is likely to be used where large areas have been affected and treatment cannot be undertaken at the same time. Unlike excisional biopsy it is purely a diagnostic procedure. When skin biopsy is performed it is essential to create an unobtrusive scar. In the foot, tissue around digits may require a section of bone to be removed in order to achieve closure. A surgeon specialising in feet should be consulted to reduce the risk of ischaemia. Needle. Aspiration is the technique used to withdraw fluids from the body, e.g. synovial fluid. Examination of synovial fluid can be very useful when examining for the presence of uric acid crystals (gout), infection or bleeding into a joint space. Where uric acid crystals are suspected the sample of synovial fluid should be placed in absolute alcohol or placed directly on to a slide. Bursae can be aspirated. This usually leads to a temporary relief of symptoms. Resected organs Partial. Partial resection or excisional biopsy involves the removal of all the abnormal tissue plus a section of the surrounding normal tissue. This procedure permits examination of the abnormal tissue as well as, hopefully, providing treatment at the same time. It is a surgical technique which requires high standards of asepsis. A scalpel is used to incise and then dissect the abnormal tissue and some surrounding normal tissue from the site. Haemostasis should be carefully performed to prevent unnecessary complications. Tissue from skin
down to muscle, ligaments and tendon will require careful repair. Ganglion formation must be removed in total as it has a high recurrence rate. The gelatinous mass is difficult to retrieve. The thin translucent membrane should be included wherever possible. Thicker membranes suggest that they have undergone longer periods of deep trauma. Complete. Whole parts, such as amputated feet, toes and excised rays, can be sent to the pathology department. Analysis of whole anatomy takes a good deal longer due to the time required to separate and fixate tissues. Bone needs to undergo a decalcification process.
Transportation and storage Laboratory personnel will discuss the best mode of collection to ensure that an appropriate sample for testing is achieved. Specimens labelled urgent are unwelcome unless requested during surgery where a quick result is necessary, e.g. in the case of a suspected malignancy, so that appropriate treatment can be performed concomitantly. Even small samples will take 24 hours to fix before the tissue can be usefully analysed. All specimens should be clearly marked with the patient's name, hospital number, site and the date/time that the sample was taken. A full history of the patient is essential. High-risk cases should be identified with a separate 'high risk' label. The specimen should be sealed in a plastic bag, the request form remaining outside. As with microbiological samples, damage can be sustained by using an incorrect method of transportation. Most tissue samples are placed in a screw-cap container containing normal buffered formalin (NBF) solution. Formalin itself constitutes a hazard, especially if spilt on living tissue. Samples for frozen section should be transported dry. They will be damaged if they come into contact with formalin. Frozen sectioning provides rapid results, usually within 5-10 minutes, and is used where results are urgently required: often when the patient is still on the operating table, when the result of the test will decide the course of action to be taken.
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Tests and interpretation of results These fall into several categories depending upon the nature of the lesion and/or suspected pathology. Slides of tissue are produced for microscopy. Often, staining techniques are used in order to show up changes more distinctively. The main purpose of histological examination is to assess whether the tissue or fluid sample differs from what is normal. Abnormal cellular findings, e.g. changes to the nucleus, may indicate malignant changes. Chronic inflammation may be evident because of the presence of lymphocytes, plasma cells and macrophages. Abnormal findings may relate to the presence of giant cells, a characteristic feature produced by foreign bodies. This is a common feature in the foot. Scarring and inflammatory changes may tether down tissue, which can account for some pain syndromes in both fore and hind parts of the foot. These syndromes are difficult to diagnose accurately other than by exploratory procedures.
Nerves fall under this category. They can show marked changes, involving abnormal blood vessels, as in the case of neuromata. Nerve conduction tests may provide evidence of damage prior to surgical investigation in the foot.
SUMMARY This chapter has covered the indications for the use of a range of near-patient and laboratorybased tests, appropriate sampling techniques, the principles of testing and interpretation of results. Emphasis has been placed on starting with the simplest tests prior to using more specific and sophisticated tests. The use of laboratory tests can never replace good interview and assessment techniques. Tests should be used economically and wisely, should cause no harm to the patient and above all should be used to support treatment, confirm diagnosis or rule out a suspected malignancy. Results should be acted upon in order to ensure that effective treatment is provided.
FURTHER READING Axford J 1996 Medicine. Blackwell Science, Oxford Bayer Diagnostics Urinalysis - the inside information Blandy J 1998 Lecture notes on urology, 5th edn. Blackwell Science, Oxford Hanno P M, Wein A J 1994 Clinical manual of urology. McGraw-Hill, New York Hoffbrand A V, Pettit J E 1993 Essential haematology. Blackwell Scientific, Oxford Karlowicz K A 1995 Urological nursing - principles and practice. W B Saunders, Philadelphia Kumar P, Clark M 1998 Clinical medicine, 4th edn. W B Saunders, Philadelphia
Philpott-Howard J 1996 Microbiology. In: Hooper J, McCreanor G, Marshall W, Myers P (eds) Primary care and laboratory medicine. ACB Venture Publications, London Quinn G 1995 Laboratory blood tests in podiatry. British Journal of Podiatric Medicine and Surgery 7(2): 24-27 Robinson S H, Reich P R 1993 Haematology, 3rd edn. Little, Brown and Company, Boston Stokes E J, Ridgeway G L, Wren M W D 1993 Clinical microbiology, 7th edn. Edward Arnold, UK Tortora G J, Grabowski S R 2000 Principles of anatomy and physiology, 9th edn. John Wiley and Sons, New York
CHAPTER CONTENTS
Introduction
341
Normal development 342 Early posture 342 Determinants of gait 342 Growth and development 343 The assessment process 343 Initiatingthe process 343 General considerations 343 Interviewing 344 History taking 344 Examination 346 Footwear 352 Conditions affecting the lower limb of children 353 Developmental dislocation of the hip (DOH) 353 Knee pain in the child 354 Abnormal frontal plane configuration of the knee 354 In-toeing problems 356 Congenital talipes equinovarus (clubfoot) 359 Flat feet 360 Toe deformities 363 Causes of limping in children 365 Infections 368 Juvenile plantar dermatitis 368 Psoriasis 368 Vasospastic disorders 368 Juvenile idiopathic arthritis 368 Summary
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The paediatric patient p. Beeson
P. Nesbitt
INTRODUCTION When assessing the paediatric patient it is important to appreciate that during the early years of life the lower limbs undergo many physiological changes and the child passes through numerous developmental milestones. The practitioner needs to be familiar with these normal changes as they will influence management. These variations in lower limb position and function can often concern the parent and confuse the inexperienced practitioner. Areas of concern can often be recognised by seeing the child walk. Observation of the child's style of gait will provide vital clues to potential underlying pathology. Furthermore, in evaluation of the restless child, scrutinising stance and gait is valuable as hands-on examination time is often reduced. Whereas a well-structured, systematic and holistic approach to assessment is encouraged, to ensure vital information is not omitted, an opportunistic approach may be desirable in cases of non-compliance. It is essential to identify, as early as possible, any problems that might need specialist treatment in order to prevent pathology in later life. This chapter considers the normal development process, presents an overview of factors which should be taken into consideration when assessing the child and reviews the assessment findings of specific conditions that arise in the lower limb of children. 341
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NORMAL DEVELOPMENT
Determinants of gait
Prior to assessing a child it is important that the practitioner has a good understanding of normal development and the approximate age by which certain milestones should be met. However, it should be remembered that variations occur even in normal healthy children. A delay in certain milestones can occur in premature babies. Table 14.1 summarises the main development stages of childhood. The developmental changes seen in children will influence both their posture and gait.
This phrase encompasses the essential developmental milestones, based on six components affecting walking. The various components (Ch. 8) commence at the time the child first starts to walk and continue to the age of 5-6. Learning skills, balance and physiological changes all contribute to the process of maturity, assisting the young child to walk as an adult walks. By the sixth year there is little to differentiate the child's gait from that of the adult. The initial stages of walking involve a 'stomping' gait with the entire limb being lifted, circumducted over the ground and then plunged down again. There is little frontal or sagittal plane movement at the pelvis. The leg is usually maintained in an externally rotated position with little transverse plane motion and the knees are in a varus position. The foot neither supinates nor pronates and there is little demand on the ankle to either dorsiflex or plantarflex. Gait is apropulsive, shock absorption minimal and velocity control poor. The child thrusts its head, the heaviest single component of the body, downwards to increase speed and up and backwards to reduce velocity. Two years of age. The child's gait will have refined considerably. The foot is still not capable of supinating at toe off; however, the pelvis is beginning to rotate in all three body planes and the leg demonstrates signs of internal rotation at heel contact. The frontal plane position of the knees is valgus. The net result is a much smoother gait. Although velocity control is improved, the arms still do not swing in coordination with the legs. Four years of age. Gait is no longer apropulsive; heel lift and the associated subtalar joint supination are apparent for the first time. Leg and pelvic rotations are now completely developed, although arm swing is still not coordinated with leg movement. Five to six years of age. Pronation-supination at the contact and propulsive phases of gait is fully developed. Stride length is increased and foot-to-ground contact time is greatly reduced compared with 12 months previously.
Early posture At 6-7 months most babies will sit unassisted (sit alone 9-12 months) and attempt to crawl. They will start to pull themselves up into a standing position and stand holding on to furniture (cruising) at 9-12 months, but they frequently fall backwards into a sitting position. By 12 months the child should be able to stand alone briefly and may possibly walk alone: 97% of children walk between 9 and 18 months; of the remainder only 6% are neurologically compromised (Luder 1988). The early walker has an immature spinal curvature which is 'C' shaped (sagittal plane), as opposed to'S' shaped in the adult. The child will have a wide base of gait for stability, with the arms flexed and held high for balance and no arm swing. The base of gait will become narrower as the child gains confidence, developing a heel-to-toe gait from 3 years of age.
Table 14.1
Main development stages of childhood
Term of reference
Age range
Neonatal Infant Early childhood Late childhood Prepubertal Puberty Adolescence Adulthood
1---4 weeks 4 weeks to 1 year 1-6 years 6-10 years 10-12 years 12-14 years 14-17 years 18 years +
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Growth and development
Initiating the process
The child's foot growth is synchronised with the body and not the limb. The foot normally doubles in length at the first and fifth month in utero. From birth to 4 years of age it doubles in size again, but after 4 years the growth rate decreases markedly. At birth many of the bones of the foot are still cartilaginous and therefore not visible on X-ray. Only bone cells with a calcium and phosphate mineral source are readily identified on X-ray film. As the diaphyses are apparent before birth, metatarsals and phalanges can be seen on plain X-ray, albeit as rather poorly defined areas. The calcaneus and talus are clearly visible on X-ray. The short bones of the midtarsus are also already formed at birth, although the navicular and cuneiforms are rather imprecise (lateral appears first at 3-6 months) and can take another 2-3 years to have a functional calcific appearance. The sesamoids of the first metatarsal appear around 8-10 years of age eCho 11). Most anatomical books will provide a useful table of ossification events and these will therefore not be considered here. When reading X-rays, knowledge of the position of the epiphyses is desirable to avoid misinterpretation: for example, the first metatarsal base is the site of the epiphysis, whereas the epiphysis of the other metatarsals is located at the metatarsal head. A knowledge of ossification is also important as far as applying effective treatment at the most appropriate time (i.e, metatarsals ossify around 14-16 years for females and 16-18 years for males). It is also useful to remember that in children some bones may appear differently orientated to those of the adult foot. The lower limb continues to grow in length and girth until the age of 19-20 years in males. Females tend to mature earlier and therefore growth usually ceases around 15-17 years.
It is usually the parent who draws attention to a foot problem in the child. Parents are often concerned about the manner in which their child is walking or are unhappy about the shape, position or size of the lower limb or foot. The parents' observations or opinions will often be based upon what they, or another family member, consider to be normal. It is the role of the practitioner to identify whether there is an abnormality or, more commonly, to reassure the parents that what appears to them to be abnormal is only part of the normal developmental process. Throughout the developing years there are recognisable features which confirm normal trends. An holistic approach to examination is indicated rather than looking at the foot in isolation. Treatment will only be required if an abnormality is progressive and can be halted. If the condition does not warrant treatment, then careful monitoring may be desirable to ensure the child develops normally.
THE ASSESSMENT PROCESS Assessment can be divided into two areas: history taking and examination.
General considerations A number of factors can influence the paediatric consultation: • previous encounters with medical intervention • the referral • the appointment • the trip • the waiting room • the interminable wait • the relatives. It is essential that the practitioner creates a relaxed and conducive environment for the assessment. The child needs time to settle and questions should always precede 'hands-on' examination. A casual approach to the practitioner's dress may be desirable. Children who have suffered discomfort at a previous medical consultation may associate a white coat with a bad experience. First-name terms may be appropriate. If the child can relate to the practitioner, he may be more willing to cooperate.
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To achieve optimal compliance with young children it is sometimes necessary to use distraction tactics: use of toys, humour and constant banter can be helpful.
Interviewing A number of cognitive aspects about children are worthy of consideration as they can influence the interview process: • • • • •
limited attention span influenced by immediate events limited experience (black and white) egocentric non-conceptual.
It is important to build a rapport with both the child and parents and not to alienate or talk down to the child. This helps develop the cooperation of the child to examination and compliance of both child and parentis) to the treatment plan. Questions should be relevant and posed using a diplomatic approach, and all explanations should be clear. It may be easier to interview the parent while the child is playing. Watching the child at play allows evaluation of motor coordination and posture. Toys should be available to facilitate this informal assessment. Sometimes young children will perceive direct questioning by a stranger as threatening, and so playing with the child first may put him at ease. Making the most of the child's natural clothing vanity is another ploy the practitioner can use to relax the child. It is important that during any assessment the child is chaperoned. The latter point cannot be ignored these days, when children may misinterpret the nature of examination if left alone with the practitioner. It may be useful to ask parents to dress the child in easy-to-remove clothing so that the process of undressing does not add to the patient's anxiety. Another person who is present - parent, nurse or care assistantcan bear witness to events. Parental dynamics can also influence the success of the consultation. The practitioner should be aware of:
• Do the parentis) and child converse or sit close together? • Do the parents assist the child in removing clothes? • Do the parents appear caring, neutral or angry towards the child? • Does the child appear confident or cling to the parentis)? A flexible approach to questioning may be necessary in cases of difficult children. If the child is uncooperative, do not hesitate to temporarily abandon the examination or reschedule the appointment for a time when the child is less tired or irritable. Advise the parents to bring along items such as personal toys to create a competitive distraction while being examined. Some children do not want to cooperate. In this case use positive statements (i.e, stand up, walk straight, stand on your toes) and be firm. Avoid giving the child a chance to be oppositional and don't be afraid to utilise the 'white coat' syndrome. Remember the practitioner's role is to help the child, not to be liked. One aspect of paediatric management is an ability to handle the parents (Meadow 1992). Always enquire specifically about the parents' concerns. Explain about the cause and treatment using plain language and avoid promoting parental anxiety by mentioning all complications. Furthermore, avoid the use of terms that might invoke unnecessary parental anxiety (e.g. chronic, progressive, delay, tumour, spastic). While it is wise to avoid raising expectations of treatment one should always end the consultation on a positive note.
History taking In order to obtain a relevant history a structured systematic approach should be adopted. This will reduce the possibility of omitting relevant information. In addition to the general questions regarding the presenting problem and medical history (Chs 3 and 5), particular attention should be paid to the following areas: • perinatal history (pregnancy and delivery) • neonatal history
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----------------------------------------------
• • • •
post-neonatal history developmental milestones family history previous consultations.
The child's age and presenting symptoms will influence the emphasis placed on the different aspects of the past medical history. In patients with congenital disorders such as talipes equinovarus, metatarsus adductus, calcaneovalgus and torsional problems, it may be useful to concentrate on the perinatal history. Perinatal history Pregnancy. It is important to ascertain whether the pregnancy was normal. Did the mother take any medication during her pregnancy? Some drugs, for example phenytoin used to control epilepsy or high doses of vitamin A, are known to be teratogenic during the first trimester of pregnancy. Smoking by the mother has been reported to retard growth in some cases and excessive alcohol intake can delay intellectual development. The practitioner must elicit information without creating anxiety. Did the mother sustain any maternal trauma or complications (threatened miscarriage, antepartum haemorrhage or toxaemia) during the pregnancy? Did she come into contact with any infections likely to cause abnormality in the child (e.g. measles, chicken pox)? Some questions may be reserved for cases where visible signs of abnormality are evident. It is important not to alarm the parent as incidental findings are rarely conclusive. The majority of babies encountered are healthy. Delivery. The mother should be asked about the nature and duration of labour. Was the delivery uneventful, full term (40 weeks) or premature? (gestational age less than 37 weeks). Muscle tone is diminished in premature babies compared to those who reach full term and an increased predisposition to developmental dislocation of the hip (DOH) and internal position of one leg is seen. Incidence of hip dislocation is higher 00 times more than occipital) when the fetus is malpositioned in utero (frank breech) or when there are twins. A Caesarean section is often indicated in
cases of frank breech, transverse lie, large size or fetal distress. Long deliveries, especially if there was fetal distress, could be significant if there is evidence of poor posture, coordination or motor function. Forceps delivery can sometimes result in temporary facial or brachial palsy. Neonatal history
At birth the baby undergoes several tests to determine their APGAR score (Apgar 1953). This routine procedure is performed at the first (index of asphyxia) and fifth (index of neurological residua or death) minute after birth. It is used to evaluate the cardiovascular, respiratory and neurological status of the neonate: • A = appearance - colour • P = pulse - indication of heart rate • G = grimace - plantar aspect of the foot is stimulated to provoke the child to cry • A = activity - muscle tone • R = respiratory effort. The child's response to each test is rated on a scale of 0-2: 2 is the maximum score. A score of 10 is the maximum and is rarely achieved; a low score below 6 is indicative of problems. Post-neonatal history
This mainly relates to feeding problems in the early months, which can influence normal growth and development. Developmental milestones
A knowledge of the normal developmental milestones is important for the recognition of suspected neurodevelopmental disorders. If neurodevelopmental delay is suspected, detailed questions on the following are indicated: • • • • • •
head control ability to sit alone ability to crawl ability to stand, walk, run ability to hop on one foot, tandem walk ability to walk up and down stairs
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• result of 8 month hearing test • ability to comprehend and obey simple commands. Family history
Family history of problems can provide vital information about the cause and the prognosis of the complaint. Are there other siblings with a similar problem? It is helpful to ascertain any family traits. These can usefully be represented by constructing a pedigree chart. In genetically determined conditions, e.g. immune deficiency states, neurodegenerative disease or muscular dystrophy, enquiries about second- and thirddegree relatives may be indicated.
the child walking, sitting, playing and how they interact with their parents. When assessing children, the focus is usually on the locomotor system. In most children a brief vascular, neurological and skin assessment will suffice. Further detailed examination should be performed in cases where the presenting problem, history taking or brief assessment indicates the presence of a significant problem. Tests should only be used in order to clarify an otherwise unclear diagnosis. Those parts of the examination process which are of particular relevance to the examination of the child are noted below.
Neurological assessment Previous consultations or advice
This should be noted as it may affect the parent's perceptions of the outcome of the child's foot problem. It must be stressed that the majority of paediatric problems are usually normal developmental variations, rarely requiring anything more than explanation and reassurance.
Examination Once a clear history has been taken, the child is examined. The younger the child, the more expedient the process needs to be. It is important to do easy/fun tests first. Tests which may be perceived by the child as threatening (e.g. hip examination) can be left until last. Sometimes it can help to examine a sibling or parent first to put the child at ease. The examination should consider the following points: • • • • • • • •
observation of gait and posture general walking capability symmetry of body obvious deformity muscle bulk and wasting joint motion vascular and skin quality footwear.
First impressions are useful and the practitioner should start with a general observation of
Neurological assessment implies motor and sensory evaluation. In the UK all neonates are examined by a paediatrician after delivery; midwives and health visitors undertake follow-up tests during the early years of development. Most neurological abnormalities will be detected during this stage. Reflexes are an important method for determining normal muscle development and innervation in the neonate. Certain involuntary (primitive) reflexes disappear after 1 year of age. Reflexes present during the first year of life are summarised in Table 14.2. The formal neurological examination of an infant will include an evaluation of the primitive reflexes, muscle tone/power, coordination (hand/eye) and posture in relation to development. Neurological examination of the child should emphasise evaluation of superficial!deep reflexes, muscle tone/power (stand on tiptoes/heels) and coordination (heel-to-toe walking, balancing on one leg, hopping). All practitioners should be mindful of skeletal and gait abnormalities which indicate a neuromuscular disorder, e.g. Charcot-Marie-Tooth disease (Case history 14.1), Duchenne's muscular dystrophy and Friedreich's ataxia. In some cases late walking may be due to neurological dysfunction undetected at birth or developmental hip dysplasia. Neurological tests should be carried out if an abnormality is suspected (Ch. 7).
THE PAEDIATRIC PATIENT
Table 14.2
347
Reflexes associated with development
Reflex
Descriptor
Oral reflex
If a finger is placed in a baby's mouth, the baby will automatically suck and swallow. Failure to suck may indicate a cerebral problem later leading to motor dysfunction in the lower limb
Mora reflex
This reflex (startle reflex) disappears by 5 months. The infant is held in a supine position with one hand supporting the head and neck. By sudden slight dropping of examiner's hand supporting head a response is elicited. The normal response is for the baby to spread his arms away from his chest with hands open and fingers spread apart followed by a movement of the arms towards the centre of his chest as if in an embrace. The legs are flexed. Failure to respond suggests weakness. Asymmetry may indicate lower spinal lesion if one leg affected. Hyperactivity suggests CNS infection and reverse Mora. Where the baby extends limbs with external rotation, this indicates basal ganglia disease
Grasp reflex
Palmar or plantar response up to 9 months. An object is placed in the palm and the fingers automatically flex to grip the object. The foot would be similarly stimulated in the area behind the toes. Failure to respond suggests CNS weakness, depending upon symmetry of reflex
Plantar reflex
This is achieved by firmly stroking the lateral sale of the baby's foot and extending the movement across the ball of the foot. A normal response in a child under 1 year is extension of the hallux. abnormal response indicates dysfunction of the upper motor neurones
An Placing and stepping/walking reflex
If you touch the anterior aspect of either upper or lower limb (anterior tibia) against the edge of an examination couch the child will lift the limb to place the foot/hand onto the surface of the couch. Alternatively, place the dorsum of the foot beneath the table top to attain the same response. This occurs in the newborn up to about 4 weeks of age. If the baby is gently held above a surface with the sales lightly contacting the surface this will elicit a stepping/walking motion. This response is present until 8 weeks of age. Absence may indicate brain damage
Tonic neck reflex
When the baby is supine and not crying, the head will be turned to one side and the arm on the same side will be extended. The other knee will often be flexed. In normal babies, passive rotation of the head will increase upper body muscle tone on the side to which the head is turned. This reflex is present up to 3 months
Patellar and ankle tendon reflex
Results should be similar to normal adult
Case history 14.1 A mother diagnosed with Charcot-Marie-Tooth disease brought her son to the clinic for assessment. She reported that he seemed to limp when tired. Gait analysis revealed a mild high-stepping gait and marked inverted heel strike. The child presented with mild forefoot valgus and a tight posterior muscle group. The foot demonstrated early signs of cavoid syndrome. Neurological tests revealed stocking distribution of hypoaesthesia and diminished reflexes. Muscle tone and bulk were reduced and the lateral compartment of the leg demonstrated early signs of peroneal muscular atrophy. Conclusion: The child is demonstrating early clinical features of Charcot-Marie-Tooth disease.
Orthopaedic assessment
This can be subdivided into gait analysis, weightbearing and non-weightbearing assess-
ment. The examination process outlined in Chapter 8 can be used with children as well as adults; however, the following specific points should be noted. Walking is perhaps the most sensitive indicator of a child's neuromuscular status. It is an ability that is refined with age and practice, yet many parents are dissatisfied with their child's style of gait - 'normal' should be distinguished from 'abnormal'. The developmental milestones such as crawling, sitting, standing and walking may vary from infant to infant. If there is undue delay, then pathology such as neuromuscular disease, mental retardation and other physical handicaps must be ruled out. Parents seek advice less frequently before their children walk. In those cases the complaint usually relates to the shape or the position that the foot or toes are adopting. Once again it is vital
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to differentiate normal development from true abnormality.
Gait analysis
Observation of the child's posture and gait on entering the clinic enables the practitioner to gain a general impression of lower limb function. It is useful to observe the child shod so as to evaluate the effect of the footwear on lower limb mechanics. The choice of footwear may be unsuitable and advice may be needed. The child should also be observed unshod wearing underclothes in order to assess the position of the lower limb, especially the knees. First, decide whether the child's gait style is appropriate for their age. As with all patients it is important to observe the child's gait from head to toe, taking note of any signs of asymmetry of posture. The head should be level in the frontal and transverse planes. In very young children the head is positioned slightly ahead of the body and may tilt downwards in the sagittal plane to improve forward momentum as the child chases their centre of gravity. Symmetry of facial features and head size should also be evaluated. The shoulders should be aligned and a child over 6 years should have symmetry of arm position (same distance from the body) and symmetrical arm swing. In static stance the arms should hang level; if they appear uneven when fingers are straightened this may suggest a corresponding shoulder drop. If shoulders are level and there is no evidence of scoliosis then anisomelia of the arms may be indicated. If one arm is held close to the body in a flexed posture neurological assessment is indicated to rule out an an upper motor neurone lesion (UMNL), e.g. hemiparesis or cerebral palsy (Fig. 14.1). Asymmetry at the level of the pelvis during walking may indicate pathology associated with a scoliosis or a limb-length discrepancy. Weightbearing and non-weightbearing examination should be performed on the spine to confirm a tentative diagnosis. Gluteal muscle weakness or paralysis associated with hip disorders will cause a distinct lateral lurch in gait (Trendelenburg gait) as the fulcrum for the muscle is lost.
Figure 14.1 An 11-year-old boy had suffered cerebral palsy following an infection. Ankle equinus with spasticity has affected the right side of his body.
Equinus may be apparent during gait; in children up to 4 years it is not uncommon to observe toe-walking. Abnormal in-toeing (common) or out-toeing should be noted. Evidence of a limp needs further investigation (see later section on limping) and the presence of a scissoring gait, indicative of spastic adductors, warrants closer neurological examination. Weightbearing assessment Spine. It is important to check the spine for shape, deformity and movement. Check for
THE PAEDIATRIC PATIENT
normal skin covering and absence of dimpling at the base of the spine over lumbar vertebrae 3/4. If a patient shows signs of dimpling, or a tuft of hair at the base of the spine, it may indicate spina bifida (Figs 14.2 and 14.3). The presence of a scoliosis, kyphosis or lordosis should be confirmed and whether it is a functional or fixed deformity. A fixed deformity is usually due to bony abnormality (structural), whereas a flexible (functional) deformity is due to soft-tissue deformity. Fixed spinal curvatures are retained when sitting and flexing the spine, especially scoliosis. Scoliosis is a frontal plane deformity but can show signs of vertebral rotation, causing a kyphotic or humped appearance in the sagittal plane. Progressive thoracolumbar problems can impair pulmonary function and in time cause strain on respiration. Marked scoliosis in children, especially where epiphyseal growth remains, must be considered potentially progressive. These patients should be sent for a specialist opinion. Lordosis is increased forward curvature in the sagittal plane, which commonly affects the lumbar vertebrae. This varies between races, Afro-Caribbeans having a larger lordotic curvature than Asians and Caucasians. Early walkers also appear to have an increased lumbar lordosis but this is due to a protruding abdomen. Hips. The Trendelenburg sign may be useful in detecting hip weakness. The Trendelenburg test
Figure 14.3
A
I I I I I I
I
I I I I I I i I I I I I I i I I I
349
Embryonic ectoderm
IIIII"'~
Dorsal neural groove
:J11!1i
j
j!
i ' j ! ! Ii i I i i , ! ! !
08 .... : ...... .:~,
B
,~
Dorsal surface Spinal cord Spinal column
~ Spina bifida occulta
•
•
~
Meninqocel
Meninqornyelocel
Figure 14.2 A. Normal development of the neural tube and spine. B. Classification of spinal dysfunction.
Hair tuft at the base of the spine seen with spina bifida occulta.
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SPECIFIC CLIENT GROUPS
-----------
is a measure of normal muscle action between the pelvis and greater trochanter (gluteus medius). If the mechanism fails, it is deemed positive (Ch. 8). Non-weightbearing assessment
Young children may be best examined on a parent's lap. The lower limb is examined for pain and swelling, obvious deformity and signs of weakness. Both limbs should appear the same regarding position, muscle bulk and tone. On examination there should be symmetry in ranges and direction of joint motion on each side. Ranges of motion change with development; however, quality of motion should be smooth and unhindered. The temperature of the limb should be warm and the limbs should be examined for dislocations, fractures, soft-tissue lumps and enlargement of bony areas. Bring the legs together and visually estimate the limb lengths at the level of the malleoli. Pelvis and hips. Altered function of the gluteal muscles due to hip dysplasia will cause a change in the shape of the buttocks. As a result the gluteal fat folds will not appear level ('anchor sign'). The central crease forms the central anchor with the two base lines along the buttocks as the bottom of the anchor. If the base lines are not level this implies asymmetry. When performing tests on the hips of children, it must be remem-
Figure 14.4
bered to avoid damaging the blood supply to the femoral head. At birth the head of the femur lies superficially in the acetabulum, which gives the appearance that the thigh is externally rotated on the pelvis. As the child develops, the head of the femur goes deeper into the acetabulum, which in turn allows the limb to internally rotate. In a normal neonate there is a ratio of 2: 1 external to internal hip rotation. With development, the amount of external rotation reduces as the amount of internal rotation increases, to the point where a normal adult value shows equal internal and external rotation of 45° in each direction. When undertaking formal hip examination it is important to evaluate flexion/ extension, abduction/ adduction and internal!external rotation in both hip-flexed and hip-extended positions (Ch. 8). This should be followed by assessment of hamstring tightness (Fig. 14.4). Comparison of the lengths of the tibiae and femurs can be performed using the Allis/skyline test (see Ch. 8). A discrepancy of limb length in an infant may be indicative of hip dislocation. In the neonate, ligamentous laxity may be present, together with instability of the hip. This is associated with circulating maternal hormones. Correct technique in hip examination is paramount so as to prevent iatrogenic dislocation or avascular necrosis of the femoral head. Nerves lying posterior to the hip joint, particularly the sciatic nerve, are subject to trauma in posterior
To determine hamstring tightness, lay the child supine, flex the hip to 90° and attempt to extend the knee to 90°.
THE PAEDIATRIC PATIENT 351
hip dislocation. Damage to the nerve may lead to motor and sensory loss. Knees. During childhood the knee undergoes a swing in the frontal plane from varus to valgus and then back towards neutral (Beeson 1999). Normal physiological bow legs (genu va rum) (Fig. 14.5) will present between birth and 2 years of age. Physiological genu valgum (knock knees) is commonly seen between the ages of 3 and 5 years (Salenius & Vankka 1975). At 4 years of age girls tend to be more knock-kneed than boys (Heath & Staheli 1993). Physiological genu valgum is generally outgrown by the age of 8 years (Beeson 1999). Some authors consider that a second episode of genu valgum may occur between 12 and 14 years of age (LaPorta 1973); this is mainly seen in girls due to the pubertal effects of growth (Cahuzac et al1995). Knee position can be assessed with the child either lying supine or standing. In the supine position the child's knees or ankles are pushed together with the legs parallel to the examination couch. The distance between the medial femoral condyles of the knees and medial malleoli of the ankles can then be measured with a tape measure.
Figure 14.5
16-month-old girl with tibia vara of both legs.
The child should be observed from the side for genu recurvatum (hyperextension). This deformity occurs in the sagittal plane. In very early childhood, genu recurvatum may be present but should reduce with development as the knee ligaments tighten. If reduction does not occur the patient should be tested for ligamentous laxity (Harris & Beeson 1998a). The range of transverse plane motion in the knee should be equal in both directions and be minimal by the age of 4 years. In the newborn 20-30° of total motion may be available (Kilmartin 1988). The amount of rotation of the tibia on the femur should reduce by 10° at 3 years of age and at 6 years of age should show minimal movement. Patellae. The position of these large sesamoids should be noted. Are they facing forward, inwards or outwards? The patellae may be up to 30° externally rotated at birth. In young children it is considered normal for the patellae to be externally rotated, but by 4 years of age the patellae should face forwards. The position of the patellae is dependent upon normal hip development. The change of direction of motion (DaM) and range of motion (ROM) at the hip, femoral torsion and reduction of external position of the femoral head allow the patellae to face anteriorly. These changes may continue until 10 years of age and may give rise to an abnormal foot position. Tibia-fibular segment. The tibiae should appear symmetrical. Signs of excessive frontal plane bowing should be noted and conditions such as Blount's disease and rickets ruled out. The calf muscles should be assessed for tone, bulk and symmetry. Exaggerated lateral calf muscles with forward facing patellae may suggest medial genicular position. The tibia and fibula twist with normal development. At birth it will be apparent that the malleoli are on the same level in the frontal plane. As development ensues, the distal end of the tibia twists externally (tibial torsion). The lateral malleolus moves to a more posterior position. There is axial rotation of the tibia and fibula as well as twisting within the bone itself. Malleolar position will reach an adult value around 6 years of age with a position of 13-18°
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SPECIFIC CLIENT GROUPS
external malleolar positioning. This represents a true external tibial torsion of around 18-25° (Elftman 1945, Lang & Volpe 1998). Medial torsional deformity (a decrease in malleolar angle) is associated with flat foot and in-toeing, whereas lateral torsional deformity (an increase in malleolar angle) is seen in pes cavus. Foot. Careful examination of each joint followed by assessment of forefoot to rearfoot alignment is indicated. The rearfoot must be examined with the ankle, the forefoot with the midtarsal joint and the toes with the metatarsophalangeal joints. Documentation of the weightbearing foot shape is also important. Ankle. In the newborn there is approximately 50° dorsiflexion and 30° plantarflexion at the ankle. The ROM at this joint decreases with development. Any limitation of ankle joint ROM needs further evaluation (see Ch. 8). There should be no deep creasing anterior to the ankle; if present, this may indicate a fixed dorsiflexed ankle (calcaneovalgus deformity). Where persistent toe-walking exists, neurological pathology needs to be distinguished from habitual causes. Rearfoot. The calcaneus will have a relatively low calcaneal inclination angle in the sagittal plane. In the neonate the neutral position of the calcaneus is 8-10° varus. The talus undergoes valgus rotation up until 6 years. The angle of declination of the talus increases, which helps bring the foot from its supinated embryonic position to its more pronated adult position. At birth the forefoot may be slightly inverted, but this will reduce with normal development. The young child has a relatively narrow heel in relation to the breadth of the forefoot. The foot should have a straight lateral border. In a rectus foot a line bisecting the heel to forefoot will demonstrate equal parts medial and lateral to the line. In an adducted foot, the medial side will appear greater and, conversely, in the abducted foot the lateral side will appear greater (Fig. 14.6). Forefoot. The midtarsus and metatarsus should be examined for frontal plane abnormalities as well as transverse abnormalities. The forefoot in the newborn is 10-15° inverted on the rearfoot (Tax 1985). The latter is easier to identify as it is more obvious. Deformity distal to the
Figure 14.6 A line through the heel should bisect the forefoot through the second or third toe. In this case the line passes lateral to the second/third toe, demonstrating a mild metatarsus adductus.
metatarsals may be directly related to the metatarsals or may be an isolated deformity. Joint laxity
Lower limb joint pain in children can sometimes be associated with ligamentous laxity (Bulbena et al 1992). This can be tested using the Beighton scale (Beighton et al 1989), a 9-point scale which assesses the degree of: • • • • •
elbow hyperextension thumb hyperextension fifth finger hyperextension knee hyperextension spine - ability to bend and touch hands flat on the floor (*) [4 x 2] = 8 + (*) = 9
Children graded with 5 points or more are considered ligamentously lax. In addition to the above, it may be noted that the child with ligamentous laxity presents with excessive eversion of the calcaneus in stance.
Footwear Evaluation of the child's footwear and hosiery is important. Children's feet should be measured on a regular basis to ensure they have not outgrown their shoes. Footwear should be of the
THE PAEDIATRIC PATIENT
353
-------------------------------------------------- - - - - - - - - - - - - - -
correct length, width and depth. Often parents present their children to clinic because they are concerned about excessive shoe wear. It is important to determine whether the shoe wear is normal or abnormal. In making this decision it is important to establish how long the shoes are worn each day, the level and type of activity the child engages in and the types of material the shoe is constructed from. Wear marks may be misleading: i.e. heavy toebox wear associated with a child using the foot as a bicycle break can be confused with a child who drags his foot due to a hemiparesis. It is important to communicate findings directly with the child, as they may be undertaking activities at day nursery that their parents are unaware of. Assessment of footwear is considered in detail in Chapter 10.
CONDITIONS AFFECTING THE LOWER LIMB OF CHILDREN Developmental dislocation of the hip (DOH) This is usually detected shortly after birth, during routine examination of the neonate by the paediatrician. However, it is possible for the condition to be missed and not picked up until later in the child's development. The fact that hip dislocation is not always congenital has resulted in a change in terminology. Congenital dislocation of the hip (CDH) is now known as developmental dislocation of the hip (DOH), thereby reflecting the continuum of developmental dislocation over time (Coleman 1994, Novacheck 1996). DOH may have serious repercussions, leading to osteoarthritis, limb shortening and hip pain. In a normal hip the quality of motion should be unimpaired when the hip is taken through its range of motion. Various tests are used to establish the presence of DOH, although feeling for displacement of the femoral head may be all that is required. It should be noted that clinical examination may produce false negatives. X-ray and ultrasound imaging can confirm a diagnosis. Barlow's test. The baby is placed supine with hips and knees flexed. Thumb pressure is
applied over the lesser trochanter with the middle finger of each hand over the greater trochanter. The femoral head is gently dislocated by moving the pressure on the hand backwards. Consequent release of pressure allows the head to slip back into position. A positive result indicates that the hips are unstable due to ligamentous laxity. The test becomes less useful as the child becomes older (Valmassy 1993). The wisdom of this manoeuvre is questionable, as the potential for avascular necrosis or neurological damage is increased by intentionally dislocating the hip joint. Palmen's sign. This is similar to Barlow's test and performed in the same manner. It is a provocative test for a subluxable (but not disloeatable) hip. If the hip is subluxable, the examiner feels a give (but not a clunk) as the femoral head is displaced partially out of the acetabulum (Harris 1997). Ortolani's manoeuvre. This is performed by flexing the hips to 90 The middle fingers are again placed over the greater trochanter and the thigh is lifted and abducted. The hip can be relocated with a palpable (rather than audible) click. This test is reliable up to 6-8 weeks of age, but clicking can arise from ligaments moving, giving false positives. Limitation of hip abduction. This test is used when the infant's dislocated hips no longer reduce with Ortolani's manoeuvre (after 2 months). Abducting the hip with the thigh and knee flexed will be resisted on the dislocated side. This is due to contracted adductors. The anchor sign is abnormal. Galleazi's sign. The infant is observed supine with hips and knees flexed and with the feet placed flat on the couch. In normal limbs the level of the knees should be equal. If one knee is lower than the other this may indicate hip pathology on the low side. This is similar to the skyline test for checking the length of the femur and tibia. Telescope (piston) sign. The hip may be out of the acetabulum but still mobile along the ala of the ilium. With the infant supine, the thigh in the sagittal plane and at right angles to the trunk, longitudinal traction may cause the head to slide 0
•
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SPECIFIC CLIENT GROUPS
up and down along the lateral side of the ala (Harris 1997).
Knee pain in the child Complaints of significant, persistent knee pain are relatively uncommon in children and usually they present with a limp or refusal to walk. The clinical history should attempt to localise the pain, determine what activities exacerbate the pain and what treatment has been provided to date. It is also useful to assess the psychosocial dynamics of the child and his family. All children between the ages of 5 and 15 years presenting with knee pain must also be evaluated for ipsilateral hip disorders (Davids 1996). A structured approach to knee assessment is essential (Ch. 8). A number of specific knee tests are indicated in children: Patella compression test. With the patient lying supine and the knee extended, the practitioner compresses the patella against the femoral condyles. If performed too vigorously it will cause pain, even in the normal knee. A more sensitive approach of gradually loading the kneecap is preferred and is less distressing for the patient. Medial facet tenderness test. The patella is displaced medially and the practitioner palpates the posterior medial surface. Performing this test also determines whether there is any tightness of the lateral capsule tending to pull the patella laterally, increasing shearing forces on the posterior facets, which may damage the articular cartilage. Quadriceps muscle bulk evaluation. The patient is asked to contract the quadriceps muscle group; the bulk of the vastus medialis muscle is assessed. Loss of muscle bulk can occur with chronic pain or poor mechanical function of the knee. Muscle function. Quadriceps muscle strength and hamstring flexibility should also be assessed. The 90: 90 test will determine hamstring tightness which, when present, will tend to flex the knee and increase patellofemoral compression. Squatting test. The patient is asked to stand on both feet and then crouch down. Patients with severe pain will express discomfort; as the knee flexes the posterior surface of the patella is com-
pressed against the femur. The degree to which squatting is restricted will indicate the severity of the condition. Anterior knee pain can occur during adolescence (more common in females). It is a recalcitrant problem which, in a minority of cases, can be disabling. The pain will be most intense during or after vigorous activity, although kneeling or sitting with a flexed knee for long periods ('cinema seat' sign) may also incite discomfort. A high 'Q' angle (see Ch. 8) has been implicated as a precipitating factor. Internal femoral rotation, external tibial rotation and genu valgum are known to increase this angle. At certain stages of development an increased 'Q' angle will be normal when physiological knee valgus is present. The 'Q' angle should reduce to 15° by 6 years of age. Osteochondroses causing knee pain. Intraarticular knee pain due to osteochondritis dissecans, characterised by primary necrosis of subchondral bone, will cause pain over the lateral side of the medial femoral condyle. Osgood-Schlatter's disease is a traction apophysitis affecting the tibial tubercle and is associated with patellar tendon strain. It predominantly affects males between 10 and 14 years of age. Pain is anterior and below the knee. It is made worse by strenuous activity. Examination demonstrates the presence of a prominent and tender tibial tubercle and quadriceps wasting may be visible. Extending the leg against resistance exacerbates the symptoms. Radiographs may show fragmentation of the tibial tuberosity at the tendon insertion.
Abnormal frontal plane configuration of the knee Parental concern about knock knees or bow legs is a common presenting complaint.
Genu varum Genu varum is normally present from birth until 2 years of age. If a child presents with bow legs at 3-4 years of age, further investigation and treatment may be necessary. A distance of more than
THE PAEDIATRIC PATIENT
Scm between the knees, at any age, is cause for concern and necessitates further investigation (Sharrard 1976). Rickets and Blount's disease are two conditions predisposing to genu vara with tibial vara. Rickets. Rickets will present as genu varum as well as anterior bowing at the junction of the middle and lower one-third of the tibia. Swelling of the wrists and ankles and bossing of the cranium is also seen in rickets. Radiological investigation will show the epiphyses to be widened and irregular, whereas the metaphyses will appear 'cupped'. Biochemical tests are performed to determine levels of vitamin 0, calcium and phosphate, which may be reduced due to dietary deficiency, malabsorption, renal disease or hypophosphatasia. If biochemical tests prove normal, Blount's disease may be suspected. Blount's disease. This is a condition affecting the growth of the medial upper tibial epiphysis. Cessation of the growth plate causes the tibia to develop a lateral varus tilt. This condition has an estimated incidence of 0.05 per 1000 live births and is due to the lateral side of the growth plate expanding faster than the medial side. Blount's disease is thought to be a combination of obesity and marked physiological bowing. This will have the effect of compressing the medial side of the growth plate, which causes further bowing of the tibia. The lateral epiphysis continues to expand as pressure is released. The medial epiphysis will appear fragmented on X-ray. Blount's disease may appear at any time between the ages of 18 months and 4 years. Referral for treatment should be initiated as the condition will invariably progress without treatment. In the infant, Blount's disease is often severe with both knees affected. Arrest of the medial growth plate may also affect older children, aged between 6 and 13, in whom the deformity is usually unilateral and less severe than the infantile variety, though no less certain to progress without treatment. Unilateral tibia vara can contribute to limblength discrepancy. Trauma, infection (McRae 1997) and fluorosis (Tachdjian 1972) can also result in marked genicular bowing.
355
Genu valgum
Genu valgum is normally present between 3-5 years of age and 12-14 years of age. In severe unremitting cases radiological examination should be used to rule out developmental or metabolic abnormalities of the epiphyses. Surgical correction may have to be considered, although this is rare. Unilateral knock knee should be investigated as it is almost always a pathological defect of the epiphysis associated with either trauma, osteomyelitis, tumour or developmental bone disturbance. Excessive subtalar joint pronation of the foot has been associated with genu valgum, as it throws body weight medial to the central axis of the foot and hence tends to force the foot into pronation. Conversely, excessive varus deformity of the forefoot may create frontal plane movement of the knee, in order to bring the entire forefoot into ground contact. Genu valgum will result.
Popliteal angle in children
The popliteal angle is defined as the angle of the tibia to the femur when the hip is flexed and knee extended. Evaluation of the popliteal angle is used to assess hamstring tightness in healthy children and hamstring contracture in cerebral palsy (Katz et al 1992). It is also used as an indicator of gestational age in infants. The mean angle in newborns is reported to be 27° and reduces to zero by age 11 months (Reade et aI1984). Hamstring, and more specifically medial hamstring, shortening is a common cause of asymmetrical hip motion and subsequent in-toeing. Diagnosis is made by flexing the hip to 90° and then attempting to extend the knee using the 90: 90 test (see Fig. 14.4). In children under 10 years, less than 70% extension is unsatisfactory. Quality of motion is also evaluated while performing the 90: 90 test. If the hamstrings resist the final 30° of motion it is usual for the child to experience discomfort, which indicates an abnormal tightness. The medial hamstring tension can be tested by internally rotating the flexed upper thigh while gradually extending the knee. If, with internal rotation of the thigh, knee extension
356
SPECIFIC CLIENT GROUPS
is limited and uncomfortable, then the medial hamstring is the principal cause of the complaint. Children with tight hamstrings can assume a normal angle and base of stance; however, during gait, as the knee extends just prior to heel contact, the tight medial hamstring will abruptly rotate the leg internally. Such cases will also demonstrate a windmilling style of running, the lower leg being circumducted during the late swing phase of running in order to 'short-cut' around the extended knee position. Growing pains are common in such in-toers, Hamstrings should therefore be tested in any child complaining of persistent nocturnal leg pains.
In-toeing problems In-toeing is often a cause for parental or grandparental concern because the child doesn't walk like his peers. Children themselves may not be unduly affected, unless their gait pattern causes tripping. It is important to establish exactly what the family's worries are, because resolving those fears provides an important goal of treatment. Sometimes, the concern is related to the child tripping or a pronated foot. Thirty percent of children in-toe at the age of 4, but the condition persists in only 4% of adults (Svenningsen et al 1990). It was once thought to cause osteoarthrosis of the hip and poor sporting ability (Alvik 1960), but it has subsequently been shown to be unimportant in osteoarthrosis of the hip (Hubbard et aI1988), while the sporting performance of women with internal femoral position has been found to be equivalent to normal controls (Staheli et aI1977). Resolution of the in-toeing gait usually occurs between the ages of 4 and 11 (Fabry et al 1973, Thackeray & Beeson 1996a, 1996b). Management of in-toeing depends upon the level at which the abnormality originates. Assessment starts with gait analysis. The key to accurate diagnosis is the position of the patella. In the in-toeing child, the patella will either point in the direction of progression or it will be internally rotated or 'squinting'. A squinting patella indicates that the cause of the gait defect is proximal to the knee joint. Severely
adducted feet in the presence of a forwardlooking patella occur in cases of internal genicular position (knee), internal tibial torsion (leg) and metatarsus adductus (forefoot). Following gait analysis, the ranges of motion at the hip and knee joint and the position of the transmalleolar axis and forefoot should be assessed. The range of hip rotation is assessed with the knee and hip extended: the leg is brought to the neutral position where the patella is facing directly upwards (parallel with the frontal plane). While viewing the patella, the leg is internally and then externally rotated and the degree of rotation estimated. In children of less than 4 years, an excessive internal range of hip motion is considered abnormal and will often explain an in-toeing style of gait. In children older than 4, asymmetry of motion may be significant. A common finding on hip examination of the in-toeing child is an increased internal range of hip motion but reduced external range of motion. In such cases there is obviously sufficient range of external motion to allow normal walking; however, the child continues to walk in-toed because it is easier to do so. The parents should be told that the child is simply walking along the line of least tension. Most children who present with internal femoral position grow out of the condition. While internal rotation falls from about 60° at age 4 to under 40° in the adult, decreasing 2-3° per year (Staheli 1993), external rotation remains at a constant 40° from 4 years of age to adulthood. The net result is loss of total rotation with age and less internal bias to gait. Tibial torsion and internal genicular position
Clinical diagnosis of internal tibial torsion is made by measuring the transmalleolar axis, which is formed between the midpoints of the medial and lateral malleoli and the frontal plane. The transmalleolar axis increases during the first few years of life from 2-4° at birth to 10-20° in the adult. Many complex methods have been described for measuring tibial torsion (Reikeras & Hoiseth 1989). A quick clinical estimation is
THE PAEDIATRIC PATIENT 357
Figure 14.7 Check malleolar position by placing the thumbs on the anterior surface of the malleoli. There should be one thumb's thickness difference between the medial and lateral malleoli.
made by placing the thumb of each hand anterior to the malleoli; the medial malleoli should be one thumb's thickness anterior to the lateral malleoli (Fig. 14.7). The incidence of internal tibial torsion has been reported to range from 1 to 40% (Hutter & Scott 1949, Michele & Nielsen 1976). In some cases the transmalleolar axis will appear normal though it is apparent on gait analysis that the whole tibia is internally rotated on the knee. This condition is called internal tibial position or internal genicular position. An internal genicular position is an important cause of in-toeing and is so similar to tibial torsion that it is quite likely to be misdiagnosed as such. Internal genicular position only becomes a cause for concern for the parents when the child starts to walk. Examination will reveal a normal transmalleolar axis but an abnormally high internal range of motion at the knee (Case history 14.2). This is estimated by stabilising the thigh and grasping the foot and rotating the tibia internally and then externally (Fig. 14.8). Normally a small but symmetrical range of motion of 10-20° will be evident. In cases of internal genicular
position, 45° or more of internal rotation may be present. External rotation usually remains no more than 10-20°, although in some cases it is completely absent. The prognosis without treatment for internal genicular position and internal tibial torsion is good. It tends to resolve spontaneously around 5-6 years of age. Its significance lies in the fact that it can cause frequent tripping. There is also evidence to suggest that it may be a factor associated with the development of osteoarthrosis of the knee (Turner & Smillie 1981). For that reason it is worthwhile monitoring the child to ensure that resolution does occur. The patient should be seen every 6 months, gait analysis performed and the range of motion at the knee and the transmalleolar axis measured. If tripping and clumsiness is severe, treatment may be considered.
.'
Figure 14.8 Internal tibial position is estimated by internally and externally rotating the tibia on the knee joint.
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SPECIFIC CLIENT GROUPS
Case history 14.2 A 2-year-old child presented with an adducted angle of gait and tibial varum. Examination revealed a normal tibial angle for the child's age; however, during gait the tibiae appeared bowed. Clinical findings revealed a forward-facing knee, with normal range of motion at the hip. Transverse motion at the tibial-femoral interface revealed excessive motion on medial rotation. An in-toeing gait pattern was evident and an exaggerated bulging of the gastrocnemius muscle on the lateral side of the leg observed due to the internal position of the leg. This gave a false impression of tibial varum. Conclusion: Medial genicular position.
Metatarsus adductus
Metatarsus adductus is a transverse plane deformity arising at the tarsometatarsal (Lisfranc's) joint. It was first recognised in 1864 by Henke, who labelled the condition metatarsus adductus. A number of other names, including skewfoot, metatarsus varus, Z foot, serpentine foot, onethird of a clubfoot and hookfoot, have subsequently been used. Some of these terms have proved useful when describing more complex variants of the basic condition. The hallmark of the deformity is a C-shaped curvature of the lateral border of the foot (Fig. 14.9). Other clinical
signs help confirm the diagnosis, including wrinkling of the skin in the medial longitudinal arch as a consequence of bunching of the metatarsal bases, a dorsal plantar crease medial to the first metatarsal cuneiform joint, a high arch profile created by adduction of the forefoot on the rearfoot and, if the child is walking, a marked tendency to lateral weightbearing. Internal tibial torsion and abnormal knee position may also occur in combination with metatarsus adductus. The cause of metatarsus adductus is unknown. A number of theories have been proposed, although intrauterine moulding remains the most popular. This theory is somewhat flawed because from the 17th week of fetal life the mother is aware that the fetus is moving, pushing up against and away from the highly elastic uterine wall. It is proposed that the direct deforming influence of constricting amniotic bands (Torpin 1968) or fetal immobility caused by loss of amniotic fluid (Blane et al 1971), both of which are associated with clubfoot, may be responsible for the development of metatarsus adductus, often referred to as 'one-third of a clubfoot' (Ponsetti 1996). Metatarsus adductus is thought to resolve spontaneously in more than 90% of cases (Staheli 1993). Ponsetti & Becker (1966) found that only
Figure 14.9 A C-shaped curvature of the lateral border of the foot is the hallmark of metatarsus adductus. This 2-year-old boy responded poorly to treatment as the deformity was quite rigid. The early management of metatarsus adductus is desirable.
THE PAEDIATRIC PATIENT
11.6% of their patients required treatment, whereas Rushforth (1978), in an Tl-year followup of 83 children, found that 86% demonstrated complete resolution of the deformity. Metatarsus adductus represents a spectrum of mild to severe deformity. Assessment of the foot's flexibility is the practitioner's primary objective (Fig. 14.10). If the foot can easily be corrected and the adductus position is mild, the prognosis for spontaneous resolution is excellent. As the deformity becomes more marked there is often a corresponding increase in rigidity. Clinical features of calcaneal eversion, medial talonavicular joint bulging and 'humping' of the dorsolateral midfoot indicate that spontaneous correction is unlikely. Uncompensated metatarsus adductus presents as a high-arched supinated foot; symptoms are usually minimal and may be limited to skin lesions under the fifth metatarsophalangeal joint. Accordingly, prognosis is less favourable and treatment should be instigated as soon as possible. Another significant finding on assessment is the presence of a vertical crease overlying the medial cuneiform. The vertical cuneiform crease presents only in the more severely affected feet. Radiographic examination can assist the evaluation of metatarsus adductus in cases of skew- or Z foot where rearfoot involvement exists. This complex variant of metatarsus adductus presents an everted rearfoot with plantarflexed and adducted talus. Several charting techniques have been developed to measure metatarsus adductus and its variants (Berg 1986). The value of radiography is limited. This is because the tarsal bones do not ossify until the patient is 3-4 years old; furthermore, in a non-weightbearing patient the plate will simply show the position the foot was held in for X-ray. In metatarsus adductus parents are often concerned about the child's adducted style of gait rather than the foot shape. To ensure consistent and reliable diagnosis, all other causes of adducted gait, including internal femoral rotation, internal tibial torsion, genicular position, compensation for a forefoot valgus and hallux varus (Jimenez 1992), must be ruled out. In conclusion, the 'level of deformity' may be quite
359
Figure 14.10 Assessing flexibility of the metatarsus adductus foot by cupping the heel in inversion while pushing the forefoot straight.
different. It is important therefore to note any element of these conditions which may be superimposed upon the metatarsus adductus, as management of more than one condition may be necessary.
Congenital talipes equinovarus (clubfoot) In congenital talipes equinovarus (CTEV), the adductus of the forefoot occurs at the midtarsal joint and not at the tarsometatarsal joint. There are four components to the deformity: equinus, inversion of the rearfoot, adductus and pronation of the forefoot. The most severe deformities, however, occur in the rearfoot. The talus is abducted and the calcaneus is in equinus. The calcaneus is also inverted, whereas the navicular is displaced medial to the head of the talus. The posterior and medial soft tissues, including tibialis posterior, flexor digitorum longus and triceps surae, are also shortened and atrophied, forming a 'pipe stem' shape to the leg. CTEV is difficult to correct and there is a high incidence of recurrence. It is well documented
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.--------------------- - - -
that it is easier to correct a clubfoot deformity in the first few days of life than after even a few weeks (Ponsetti 1992). Assessment of the clubfoot should address the relative severity of each of the four components of the condition. The plantarflexed first metatarsal component is critical but usually yields well to manipulative correction. The equinus and inversion components of the rearfoot and the adduction of the forefoot at the talonavicular joint are more resistant to correction (Ponsetti 1996). Internal tibial torsion may also occur with clubfoot and must be also be corrected. No matter how effective initial treatment, clubfoot will always result in shortening of the foot, reduced calf muscle circumference and reduced ankle and subtalar joint motion. Medial displacement of the navicular and abduction of the talus on the calcaneus may also persist. In less well corrected clubfeet, poor gait and abnormal forefoot loading results in plantar callus and shoefitting difficulties. The Ilizarov technique has been used for the correction of persistent deformities (Wallander et aI1996).
Flat feet Flatfoot is one of the most common conditions seen in paediatric podiatry clinics. There is no universally accepted definition for flatfoot. Morley (1957) suggested that children under 5 years of age appeared to have flat feet because the medial longitudinal arch was filled with fat. Radiological studies of toddlers' feet have subsequently proved Morley wrong. All children under 5 years have a depressed medial longitudinal arch because of the low calcaneal inclination angle and the underdeveloped sustentaculum tali. It is only with external torsion of the tibia, in the first 5 years of life, that the calcaneus begins to assume its normal 20° angle of inclination and the medial longitudinal arch becomes apparent. However, in the neonate, fat deposits are retained for a short period and tend to be quite marked on the dorsum of the foot. This fat distribution does contribute to an immature foot shape, which disappears quite rapidly after the first 12 months.
'Flatfoot' is a common term used by health care professionals and lay people alike. 'Excessive pronation of the foot' is a more accurate term because, as well as a lowered medial longitudinal arch, the flat foot may also present the following clinical signs (Fig. 14.11): • calcaneal eversion • bulging of the talus (talonavicular joint subluxation) • abduction of the forefoot • 'too many toes sign' • 'C' -shaped lateral border. Helbing's sign, described as a bowing of the calcaneal tendon as it inserts into the calcaneus, can sometimes be associated with excessive pronation. Helbing's sign is not always reliable because in some cases of excessive pronation it is not seen. This is so when the foot maximally pronates from a supinated position associated with rearfoot varus. Pronation can occur using the available range of subtalar joint motion, but the calcaneus may still remain in a relatively inverted position. This is commonly referred to as 'partially compensated rearfoot varus'. Marked eversion of the calcaneus will inevitably lower the medial longitudinal arch. With calcaneal eversion there will also be abduction of the distal end of the calcaneus, allowing the talus to assume a more adducted and plantarflexed position which can be seen clinically as medial bulging in the area of the talonavicular joint. Once congruency is lost at the talonavicular joint, progressive subluxation of the joint follows. As the talus ad ducts, the forefoot will assume an abducted position relative to the adducted rearfoot. This abnormality will manifest clinically as the 'too many toes sign'. When a normal foot is observed from the rear, it is possible to see the fifth and sometimes the fourth toe. In a pronated foot the third toe may be seen as well. The lateral border of the foot will be C-shaped with the concavity of the 'C' overlying the calcaneocuboid joint. The aforementioned clinical signs associated with excessive pronation will occur with varying degrees of severity. In some cases the only abnormality will be a lowering of the medial longitudinal arch: all other signs will be absent. Such
THE PAEDIATRIC PATIENT 361
Figure 14.11 A 10-year-old boy with moderate pronation. Calcaneal eversion, medial talonavicular bulging and forefoot abduction characterise excessive subtalar joint pronation associated with forefoot varus of both feet.
feet are not a cause for concern; indeed, a study of 295 Israeli army recruits undergoing basic training found that the incidence of stress fractures was reduced in individuals with lowarched feet (Giladi et aI1985). When evaluating the child's pronated foot the practitioner must consider other risk factors that may affect the foot in its overall development (Napolitano et al 2000). These contributing factors may influence the treatment plan. The risk factors include: • • • • • • •
obesity ligamentous laxity hypotonia (Down's syndrome) rotational deformities frontal plane tibial deformities equinus tarsal coalitions.
Objective assessment of the pronated (flat) foot is vital in order to measure how the patient's foot is changing with the passage of time or indeed how it is responding to treatment. Staheli et al (1987) developed the arch index as an indicator of foot pronation (Fig. 14.12). The narrowest point of the arch width was divided by the widest point of the heel width to give an arch index value. Staheli recommended that his graph
of normal values should be used to determine which children were abnormal and required treatment. However, in practice, Staheli's normal limits have proved to be very wide. Moreover, the height of the arch alone is not a reliable indicator of excessive pronation of the foot as the arch is not flat in every pronated foot. Some
AlB 2.0 1.8 1.6 1.4 1.2 1.0 .8 .6 .4
.2 0
o
2
4
6
8
10
12
1415-19 30's 50's 70+
Figure 14.12 Staheli's table of normal arch index values. The mean value for the arch index and two standard deviations for each of the 21 age groups. The solid line shows the mean changes with age; the shaded area shows the normal ranges. The actual values for each age group are represented by solid circles for the mean and open circles for two standard deviations. (Reproduced by kind permission of the Journal of Bone and Joint Surgery.)
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patients will present with calcaneal eversion and talonavicular bulging, but the medial longitudinal arch may still be apparent. Rose's valgus index (Rose et al 1985) takes into account the eversion of the foot relative to the leg and can be used in conjunction with Staheli's index to obtain more valid information about the degree of pronation (Fig. 14.13). Rose's technique measures the displacement of the medial malleolus relative to the weightbearing surface of the heel. The more the foot pronates, the greater the medial displacement of the malleoli. The Rose and Staheli indices should be used to determine objectively foot position and arch height. Footprints should be repeated once yearly in an attempt to identify change. The decision as to which children require treatment should be based upon an assessment of the magnitude of their symptoms, family history and the footprint indices. The patient with excessive pronation may suffer from chronic low-grade discomfort in the medial longitudinal arch, talonavicular area, or leg muscle pain, or even all three. The tibialis anterior muscle is particularly prone to causing
discomfort where the foot is excessively pronated. This is because the excessive pronatory movement of the foot causes the muscle to work aphasically, leading to overuse. In many cases, such leg pain may be written off as untreatable 'growing pains'. The condition is, however, very responsive to conservative orthotic treatment. Whereas the young patient's foot may be severely pronated, it usually remains quite flexible, as demonstrated by the hallux dorsiflexion (Jack's test) and tiptoe-standing tests. This invokes the windlass mechanism associated with the plantar aponeurosis, affording a rise in arch height where the foot is flexible (Case history 14.3). This test is negative for rigid flat feet. In a rigid pronated foot the arch will not rise upon dorsiflexion of the hallux; neither will the rearfoot invert when the individual stands on tiptoes. The swivel test, where the child is asked to turn their upper body in stance and look over one shoulder while the foot on that side is observed, can be useful. If the foot demonstrates a supination movement with arch rise, this signifies a flexible foot. The supination resistance test can also be used. With the child weightbearing, the examiner places two fingers on the plantar aspect of the navicular and pushes up. If arch rise is observed with this manoeuvre a flexible foot is indicated. All of these tests are used to demonstrate whether the tarsus is flexible or not.
r---
I
Figure 14.13 Rose's valgus index. Footprints to show diagnostic features A. The orientation ofthe heel oval, in this case pointing towards the second toe B. The medial pressure pattern which is commonly found in flat foot C. To show the measurements for calculation ofthe valgus index, which equals 1/ 2 AB - AC x 1DDIAB where A and B are vertically beneath each malleolus and C is the centre of the heel print. (Reproduced by kind permission ofthe Journal of Bone and Joint Surgery.)
Case history 14.3
Two brothers age 8 and 10 years presented with excessively pronated feet in relaxed calcaneal stance with severe talonavicular bUlging. Both boys experienced foot fatigue bythe end of the day and pain in the styloid process. Their gaitwas excessively abducted and apropulsive. Jack's test and the tiptoe test were positive, demonstrating a flexible flat foot. The posterior tibial tendon was anteriorly displaced overthe medial malleoli, rendering itan inefficient invertor and plantarflexor ofthe foot. The peroneal muscles werecontracted. Both boysdemonstrated 6 on the Beighton scale. ConclusIon: A diagnosis of severe flexible flatfoot primarily caused by malposition of posterior tibial tendon and tightness ofperoneal muscles and aggravated by ligamentous laxity.
I
THE PAEDIATRIC PATIENT
Rigid flat feet
A rigid pronated foot is a rare but significant finding, usually indicative of tarsal coalition and peroneal spastic flat foot. Tarsal coalition is a fibrous, cartilaginous, or osseous union of two or more tarsal bones and is congenital in origin (Mosier & Asher 1984). Coalition between the calcaneus and the navicular and the middle facet of the subtalar joint is the most common presentation and is conclusively linked with the syndrome of peroneal spastic flat foot, which is a painful rigid pronation of the foot with tonic spasm of the peroneal muscles. Tarsal coalitions usually become painful during the second decade of life when the coalition starts to ossify, and may be associated in the rearfoot with a sudden injury. The child will present with mild deep pain in the subtalar joint and limitation of subtalar joint movement. Generally the more severe the limitation of movement, the more severe the pain. Talocalcaneal coalition tends to produce the most severe pronation of the foot. If the tarsal coalition has ossified, its presence can be confirmed by radiographic examination of the foot. The calcaneonavicular coalition is best demonstrated by a medial oblique radiograph. In non-ossified calcaneonavicular coalition the proximity of the two bones and flattening of the navicular as it approaches the calcaneus should arouse suspicion. Bone scans are useful for coalitions difficult to diagnose radiographically, particularly of the talonavicular joint. Th.e talocalcaneal joint most commonly shows a coalition in the middle facet, which can be seen on plain X-ray (Harris-Beath or ski-jumper's view), of the rearfoot; however, computed tomography (CT) is considered the gold standard. Magnetic resonance imaging (MRI) is particularly useful in the immature, before ossification of tarsal bones is complete (Kulik & Clanton 1996). The peroneal muscle spasm, which may be occasional or continuous, is probably the response of the peroneal muscles to effusion into the subtalar joint. It has been demonstrated that the posterior subtalar joint intra-articular pressure is less in eversion than in inversion (Kyne & Mankin 1965). The peroneal spasm can be reduced by a local anaesthetic block of the
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common peroneal nerve as it passes around the neck of the fibular (Harris 1965). The spasm, a protective mechanism, can be induced by forceful inversion of the foot. The swivel test can also be used to determine whether the subtalar joint (STJ) is at its end of ROM. This is particularly useful in rigid flat feet. The child is asked to look over one shoulder while the practitioner observes the calcaneus of the foot on the opposite side. If the foot fails to pronate more, then the STJ is considered to be functioning at its end of ROM.
Toe deformities Hallux valgus
While not a common condition, juvenile hallux valgus is a very significant foot problem. Although it begins as an isolated abnormality of the first metatarsophalangeal joint, as the condition progresses it affects the entire forefoot. Advanced hallux valgus is known to be associated with hammer second toe and crowding of the other lesser digits, widening of the forefoot leading to footwear-fitting problems, and plantar callosity and metatarsalgia. A survey of 6000 9-year-olds determined a 2% incidence of hallux valgus (Kilmartin et al 1991). Although it is possible to detect hallux valgus in children younger than 9 years, the changes are often very subtle. On the other hand, in adolescents the condition may have already progressed to the point where it is involving the lesser toes. Therefore, 9 years is probably the optimum age for assessment and treatment. The condition is known to be inherited (Johnston 1959), so children with the complaint are often presented by parents who are only too familiar with the long-term effects of 'bunions'. Diagnosis may be confirmed using the following three criteria: • A first metatarsophalangeal joint angle in excess of 15°. This may be measured clinically with a digital goniometer or on a dorsoplantar weightbearing X-ray. If radiographs are taken, the first-second intermetatarsal angle should also be
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measured. An angle in excess of the normal 9° is known to be the forerunner of clinically apparent hallux valgus (Kilmartin et al 1994). • Osteophytic thickening of the first metatarsophalangeal joint. Visible thickening of the joint indicates hypertrophy of the metatarsal head caused by loss of congruency of the joint and subsequent early degeneration of the joint surface. • A strong family history of the complaint. A family history of hallux valgus, while not confirming diagnosis, must arouse suspicion. When hallux valgus is present in the child, family history may also indicate the likely prognosis for the child. A history of severe deformity affecting siblings, parents and grandparents is very significant. Hypermobility may be a predisposing factor for juvenile hallux valgus; therefore, the screening of all children with hypermobility for hallux valgus would be beneficial (Harris & Beeson 1988b). Pain is not usually a feature of hallux valgus until the deformity is more advanced. Pain can be associated with footwear irritation of the skin overlying the medial eminence. Because of the progressive nature of hallux valgus, once the diagnosis is made, assessment and review is likely to be a long-term commitment for both patient and practitioner. Dorsoplantar weightbearing radiographs will allow accurate assessment of the following: • • • • • •
first metatarsophalangeal joint space hallux valgus angle first-second intermetatarsal angle medial eminence osteophytic development sesamoid position.
Radiographic changes are likely to be very subtle in the short term. Three yearly X-ray reviews are therefore indicated. Objective clinical assessment can be made by taking a digital goniometer measurement of the first metatarsophalangeal joint angle. This value should be recorded after drawing around the weightbearing foot on a blank sheet of paper. When stored in
the patient's records, this can provide a visual indication of the effectiveness of treatment. Because hallux valgus is usually a bilateral condition, both feet can be assessed in this manner even if at first only one foot is affected. Lesser toe deformity
The following lesser toe deformities are common cause for parental concern: • • • •
adductovarus third, fourth, fifth toes dorsiflexed second toe overriding fifth toe underriding third and fourth toes.
Although the abnormal position is often real enough, the condition may be quite benign. It is essential that the practitioner applies the following criteria to determine which lesser toe problems require treatment: • Is weightbearing on the apex of the toe rather than the soft plantar pulp? Apical weightbearing may lead to the development of painful corns and callus. • Is the malposition of one toe likely to influence the position of an adjacent, otherwise normal toe? For example, a dorsiflexed second toe will lead to loss of buttress effect on the hallux, which will predispose to hallux valgus. • Is the malpositioned toe likely to be irritated by footwear or cause footwear-fitting problems? • Is the type of toe deformity likely to respond to conservative or surgical treatment? Transverse and frontal plane deformities are resistant to conservative treatment, whereas sagittal plane deformities and even the sagittal plane component of complex digital deformities respond more favourably to conservative treatment. In children older than 9, conservative treatment becomes progressively less effective. In infants younger than 2, corrective devices are poorly tolerated and technically difficult to make because of the size of the toes. If treatment is indicated, conservative treatment should always be attempted first. Response to treatment may be monitored using a Harris & Beath mat. The child should be asked to step on
THE PAEDIATRIC PATIENT
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and then off the mat. Digital purchase will be recorded by the mat. A Musgrave pressure system can also provide useful information. Apical weightbearing by the digits will be recorded as a very small area of digital contact, whereas adductovarus will often appear as the lateral side of the digit in contact with the mat. In overriding digits, toe purchase with the ground will be absent. Following treatment, the foot printing procedure should be repeated. Drawing around the toes on blank paper, photocopying the undersurface of the foot while supporting the child's weight, or photographing the digits will also facilitate objective assessment of treatment success.
Causes of limping in children The painful limb / foot in the child is a cause for concern. Limping is abnormal, and few parents tolerate the problem for long before seeking medical help. The child who limps presents a diagnostic problem, as there are numerous conditions that may result in limping (Table 14.3). It is the practitioner's role to determine the likely cause. First, localise the problem in terms of anatomical structure. Careful systematic evaluation from the pelvis distally will help. Next, determine the cause, e.g. trauma. In young children physical signs rather than subjective symptoms will playa major role in determining aetiology. Communication is limited and so true clinical acumen is demanded. Thorough questioning of the parents is crucial. It is easy to be led to false conclusions, since pain may be influenced by psychological factors, subjectivity and referred pain (from the hip to the knee). History
To arrive at a correct diagnosis it is paramount that a detailed history is obtained. The exact circumstances surrounding the onset and duration of the limp must be carefully and sympathetically explored. An episode of trauma is frequently blamed as the cause of the limp, but may
be misleading. Conversely, an innocuous incident associated with minimal trauma may fracture a pre-existing unicameral bone cyst of the calcaneus or bone weakened by a tumour. A number of specific questions should be considered (Table 14.4). Limping after vigorous activity may be the first clue to an impending stress fracture. Rather than limp, the child may refuse to walk or stand and ask to be carried. If pain is associated with the limp, its exact location and pattern should be explored with the child. The pattern of referred pain in children appears to be stronger than in adults (e.g. pain referred to the knee due to medial hip problems such as slipped capital femoral epiphysis (SCFE) or osteoid osteoma). The character of the pain may be helpful, such as the constant pain from an expanding tumour or infection versus pain related to joint motion. Conditions which lead to demineralisation of bone frequently cause generalised pain, particularly in the weightbearing bones. Lower extremity pain and limping may be the first signs of systemic illness such as juvenile idiopathic arthritis (JIA), leukaemia, Gaucher's disease or chronic renal disease. The age of the patient will make certain diagnoses more suspect: • developmental dislocation of the hip in the young child • Perthes' disease or toxic synovitis of the hip in 5-7 year olds (more common in males than females on a 6:1 ratio) • Kohler's oseteochondritis of the navicular (5-12 year olds) • heel pain (Sever's traction apophysitis) in 9-12 year olds • SCFE or anterior knee pain in young adolescents 02-15 years age). Osteochondroses such as Perthes', Kohler's, and Freiberg's diseases are a group of disorders associated with trauma and altered vascular supply to bone (DeValentine 1992) which commonly cause limping in children. Other examples of osteochondroses affecting the foot are given in Table 14.3.
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Table 14.3
Limp relating to specific location
Location Nervous system CNS
PNS/ muscle
Possible causes
Cerebral tumour Cerebral palsy Spina bifida Spinal muscular atrophy Poliomyelitis Friedreich's ataxia Muscular dystrophy Charcot-Marie-Tooth disease
Back
Trauma Acute appendicitis Herniated nucleus pulposus (slipped disc) Scheuermann's disease of the spine (osteochondritis of spine) Spondylolisthesis (forward displacement of vertebra on one distal to it)
Hip
Developmental dislocation of the hip (DDH) Slipped capital femoral epiphysis (SCFE) Transient synovitis of the hip Legg-Calve-Perthes disease Trauma Coxa vara (provokes waddling gait) Trochanteric bursitis
Femur/tibia
Fracture (fractured femur may present as hip or knee pain) Blount's disease Limb-length inequality (short femur or tibia)
Knee
Osgood-Schlatter's disease (traction apophysitis) Osteochondritis dissecans Chondromalacia Haemophilia Sickle-cell anaemia Rickets Baker's cyst Referred pain from hip
Ankle/foot
Fracture/sprai n Rickets (ankle) Osteomyelitis (calcaneus) Unicameral bone cyst (calcaneus) Sever's disease (traction apophysitis) Osteochondroses - Mouchet's or Diaz/K6hler's/ Buschke's/Freiberg'slTreve's disease Haglund's disease (osteochondrosis of accessory navicular) Iselin's disease (traction apophysitis) Accessory navicular - type II (Romanowski & Barrington 1991) Tarsal coalition Embedded foreign body in foot Verruca Onychocryptosis Subungual exostosis
Miscellaneous
Septic arthritis (juvenile idiopathic arthritis) Angioleiomyoma Leukaemia Attention-seeking device Child abuse
THE PAEDIATRIC PATIENT
Table 14.4 Questions the practitioner should consider when assessing a child with a limp
• Is the limp constant or intermittent? • Is the limp only present in the morning, at the end of the day when the child is fatigued or is it present throughout the day? • What is the posture of the lower extremity when the child is limping? • What is the effect of climbing stairs or running? Did the limp start following vigorous activity?
Physical examination
Gait assessment should be preferably undertaken unassisted by the parent. The uncooperative child is best assessed when he thinks the examination is finished. Stiffness or limitation of motion of a single joint forces the surrounding joints to compensate by increased movements. This results in an irregular or jerky gait, such as the forward thrust of the pelvis with a stiff hip or hiking the pelvis to swing through a stiff knee. Positional change may occur, such as external rotation of the foot to accommodate a stiff ankle and limited dorsiflexion or external rotation of the entire limb in SCFE. Sometimes it is helpful to accentuate the limp by asking the child to walk on his toes or heels. Listening to the gait can be informative: the slapping of the foot in drop foot, the scraping sound of spastic gait or the quick soft steps of an antalgic gait. Inspecting the shoes for abnormal wear is useful: increased toe wear in toe walkers, destruction of the medial shoe counter in severe abnormal pronation. A non-weightbearing evaluation will help to clarify initial impressions about the limp. Joints should be examined individually and compared to the contralateral side and with expected normal values, in particular observation for joint stiffness, limited motion or guarding. Marked changes to joint angle measurements indicate disease or injury and should not be attributed to immaturity. Joint stiffness frequently accompanies synovial swelling and/ or joint effusion as seen in JIA, whereas laxity of a joint generally points to a ligamentous problem. In the hip, telescoping or pistoning are the classic signs of dislocation. A formal knee exam-
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ination may be required to exclude knee pathology. Measurement of limb lengths is important, as limb shortening may be an early sign of a dislocated hip. Cutaneous changes should not be overlooked. Extra skin folds, cafe au lait spots, erythema or heat may provide an excellent clue to diagnosis. A complete neurological examination including evaluation of muscle function and strength is important. A neurological abnormality is frequently the underlying cause of many difficult to diagnose limp problems (e.g. the child with early Charcot-Marie-Tooth disease who presents with a mild cavus foot and toe clawing). Subtle variations in neurological function may only be noticeable with weightbearing or following vigorous activity. The Trendelenburg test (ability to stand on one foot) is a valuable clue to limb stability. Most normal children over 4 years of age can sustain this position for a minimum of 30 seconds. Less time (a delayed Trendelenburg) may suggest weakness of the hip abductors or hip instability associated with acetabular dysplasia. Weakness of a specific muscle is usually due to a local problem (e.g. quadriceps atrophy accompanying a knee complaint), whereas weakness of muscle groups is usually associated with primary muscle diseases, systemic illness or neurological problems (Hensinger 1986). Certain limping patterns are characteristically associated with weakness of specific muscles. Tightness or spasticity of the muscles and poor voluntary control are good clues to mild cerebral palsy. Similarly, running accentuates the flexion and posturing of the upper limb in a child with mild spastic hemiplegia. Rupture of the calcaneal tendon will lead to drop foot; Thompson's test should be performed (Ch. 8). Hamstring inflexibility can result in a flexed knee gait with abrupt internal rotation of the leg at heel strike, particularly if the medial hamstrings are tight. Limited straight leg raising can be associated with hamstring inflexibility, but also other causes such as discitis or spondylolysis and spondylolisthesis need to be excluded (Fields 1981). These usually give rise to back pain, which radiates laterally into the buttocks.
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Special tests
Psoriasis
The history and physical examination may be supplemented by a variety of radiological or laboratory tests, depending on the clinical assessment of the child. Generally, start with non-invasive tests, then progress to more invasive tests as indicated. Due to the diffuse nature of pain patterns in children, a larger area may be exposed than might be chosen for an adult, e.g. radiographs of the hip and knee when a problem is suspected in the femur. Radiographs should include anteroposterior and lateral views of the area and comparison views of the uninvolved side. In acute osteomyelitis where bone changes may not be seen for 7-10 days a bone scan may be more helpful. Laboratory studies include blood count, differential, erythrocyte sedimentation rate (ESR), blood cultures or direct aspiration. The ESR is normal in trauma, the osteochondroses and SCFE, whereas it is raised in osteomyelitis, septic arthritis, JIA and malignancy. More complex and invasive tests should be reserved for the more complicated cases.
Acute guttate psoriasis is the commonest form in the young and often related to a minor infection such as a streptococcal sore throat. The rash either subsides in about 6 weeks or progresses to plaque psoriasis (Beeson 1990). Plaque psoriasis mainly affects the extensor surfaces but occasionally the flexures. The latter may involve the interdigital web spaces and nail folds.
Infections Verrucae are endemic in children, particularly between 6 years of age and the late teens. The source of the viral infection is often hard to identify and advice will depend upon duration, symptoms, activities and attitude toward the problem. The presence of tinea pedis can be diagnosed from skin scrapings; teenage boys are particularly susceptible to fungal infections associated with hyperhidrosis.
Juvenile plantar dermatitis Another seasonal condition is forefoot eczema or juvenile plantar dermatosis (Ch. 9). The aetiology is uncertain but it is not thought to be a chronic contact dermatitis. A rash appears on the weightbearing area of the foot. A pink, shiny or glazed appearance is noted with scaling. The skin thins and is inflexible, with resultant fissures forming. Differential diagnosis includes tinea pedis.
Vasospastic disorders These used to be very common in children because of poor economic and housing conditions. Their incidence has declined in recent decades. However, chilblains still occur in children who are exposed to extremes of temperature due to inadequate footwear and hosiery in winter or poor home conditions. They appear as red, blotchy, intensely itchy areas. Broken chilblains may become infected. Dark mauve swellings around calf muscles, thighs and buttocks indicate erythrocyanosis. This affects overweight females in particular. Acrocyanosis, reddening of the hands and feet, may also occur in children. Both erythrocyanosis and acrocyanosis are indicative of poor blood supply and response to cold.
Juvenile idiopathic arthritis (JIA) JIA, previously known as juvenile chronic arthritis, is one of the most common chronic illnesses of childhood. It affects 1 in 1000 children (Malleson & Southwood 1993) and is a major cause of functional disability. The child with JIA may present with lower limb pain. Both forefoot and rearfoot deformities are common; however, the type of deformity is difficult to predict due to the influence of other joint deformities and the child's age when the disease is active (Beeson 1988). Treatment is based upon maintaining a good lower limb position with splints/orthoses, maximum muscle strength, a full range of joint motion and appropriate footwear. The use of a team approach in the management of this condition is paramount (Beeson 1995).
THE PAEDIATRIC PATIENT
SUMMARY Although the assessment process is similar, the skills required to assess the child do differ from those used to assess an adult. Assessment of the child requires sufficient knowledge of normal development and the ability to differentiate between self-limiting developmental conditions and significant, persistent abnormalities, and those that warrant further evaluation. The practitioner must appreciate normal developmental milestones in order to undertake a thorough assessment. This chapter has primarily concentrated on
369
common paediatric orthopaedic conditions of the lower limb. Brief discussion has considered pertinent vascular, dermatological and arthritic conditions that lead to patients seeking advice. The practitioner must identify the cause of any pain and be vigilant for signs of neuromuscular deficit. In a well-resourced nation such as the UK, most severe problems associated with the foot and lower limb are detected at birth. However, all practitioners should be aware of problems that may have missed detection or which are relatively mild but may still lead to functional problems in later life.
REFERENCES Alvik L 1960 Increased anteversion of the femoral neck as a sole sign of dysplasia coxae. Acta Orthopaedica Scandinavica 29: 301-306 Apgar V 1953 Evaluation of the newborn infant. Current Research Anesthesia Analgesics 32: 260 Beeson P 1988 Juvenile chronic arthritis: the foot. The Chiropodist 43(2): 20-26 Beeson P 1990 The clinical significance for chiropodists of recent advances made in the pathology and treatment of psoriasis. Journal British Podiatric Medicine 45(3): 43--46 Beeson P 1995 Podiatric perspective: a case study of rheumatoid arthritis and a multidisciplinary approach. British Journal Therapy Rehabilitation 2(10): 566-571 Beeson P 1999 Frontal plane configuration of the knee in children. The Foot 9(1): 18-26 Beighton P H, Grahame R, Bird H A 1989 Hypermobility of joints, 2nd edn. Springer, Berlin Berg E E 1986 A reappraisal of metatarsus adductus and skewfoot. Journal Bone and Joint Surgery [Am] 68-A: 1185-1196 Blane W A, Mattison D R, Kane R 1971 LDS intrauterine amputations and amniotic band syndrome. Lancet 2: 158 Bulbena A, Duro J C, Porta M et al 1992 Clinical assessment of hypermobility of joints: assembling criteria. Journal Rheumatology 19(1): 115-122 Cahuzac J Ph, Vardon D, Sales de Gauzy J 1995 Development of the clinical tibiofemoral angle in normal adolescents. Journal Bone and Joint Surgery [Br] 77-B: 729-732 Coleman S S 1994 Developmental dislocation of the hip: evolutionary changes in diagnosis and treatment [Editorial]. Journal Pediatric Orthopedics 14: 1-2 Davids J R 1996 Pediatric knee: clinical assessment and common disorders. Pediatric Clinics of North America 43(5): 1067-1090 DeValentine S D 1992 Foot and ankle disorders in children. Churchill Livingstone, New York, pp 452-458 Elftman H 1945 Torsion of the lower extremity. American Journal Physiology and Anthropology 3: 255-265 Fabry G, McEwan G D, Shands A R 1973 Torsion of the femur (a follow up study in normal and abnormal
conditions). Journal Bone and Joint Surgery [Am] 55A: 1726-1738 Fields L 1981 The limping child: a review of the literature. Journal American Podiatric Association 71(2): 60-64 Gauthier G, Elbaz R 1979 Freiberg's infraction: a subchondral bone fatigue fracture. A new surgical treatment. Clinical Orthopedics Related Research 142: 93-95 Giladi M, Milgrom C, Stein M et al 1985 The low arch, a protective factor in stress fractures. Orthopedic Review 14: 709-712 Harris E J 1997 Hip instability encountered in pediatric podiatry practice. Clinics in Podiatric Medicine and Surgery 14(1): 179-208 Harris R 11965 Peroneal spastic flat foot (rigid valgus foot). Journal Bone and Joint Surgery [Am] 47-A: 1657-1667 Harris M-C R, Beeson P 1988a Is there a link netween juvenile hallux abducto valgus and generalised hypermobility ? A review of the literature. Part I. The Foot 8(3): 125-128 Harris M-C R, Beeson P 1988b Generalised hypermobility: is it a predisposing factor towards the development of juvenile hallux abducto valgus? Part 2. The Foot 8(4): 203-209 Heath C H, Staheli L T 1993 Normal limits of knee angle in white children ~ genu varum and genu valgum. Journal Pediatric Orthopedics 13: 259-262 Hensinger R N 1986 Limp. Pediatric Clinics of North America 33(6): 1355-1364 Hubbard D D, Staheli L T, Chew D E 1988 Medial femoral torsion and osteoarthrosis. Journal Pediatric Orthopedics 8:540-542 Hutter C G, Scott W 1949 Tibial torsion. Journal Bone and Joint Surgery [Am] 31-A: 511-518 Jiminez A L 1992 Hallux varus. In: McGlamry D E, Banks A S, Downey M S (eds) Comprehensive textbook of foot surgery, 2nd edn. Williams & Wilkins, Baltimore, pp 587-588 Johnston 01959 Further studies of the inheritance of hand and foot anomalies. Clinical Orthopedics 8: 146-159
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Katz K, Rosenthal A, Yosipovitch Z 1992 Normal ranges of popliteal angle in children. Journal Pediatric Orthopedics 12:229-231 Kilmartin T E 1988 Medial genicular rotation: aetiology and management. The Chiropodist 43: 181-184 Kilmartin T E, Barrington R L, Wallace W A 1991 Metatarsus primus varus. Journal Bone and Joint Surgery [Br] 73B: 937-940 Kilmartin T E, Barrington R L, Wallace W A 1994 A controlled prospective trial of a foot orthosis in the treatment of juvenile hallux valgus. Journal Bone and Joint Surgery [Br] 76B: 210-214 Kulik S A, Clanton T 01996 Tarsal coalition. Foot and Ankle International 17(5): 286-296 Kyne P J, Mankin H J 1965 Changes in intra-articular pressure with subtalar joint motion with special reference to the etiology of peroneal spastic flat foot. Bulletin of the Hospital for Joint Diseases 26: 181-186 Lang L M G, Volpe R G 1998 Measurement of tibial torsion. Journal American Podiatric Medical Association 88(4): 160-165 LaPorta G 1973 Torsional abnormalities. Archives Podiatric Medical Foot Surgery 1: 47-61 Luder J 1988 Early recognition of cerebral palsy. Update 15 March: 1955-1963 McRae R 1997 Clinical orthopaedic examination. Churchill Livingstone, Edinburgh, pp 231-238 Malleson P N, Southwood T R 1993 The epidemiology of arthritis: an overview. In: Southwood T R, Malleson P N (eds) Bailliere's clinical paediatrics international practice and research. Bailliere Tindall, London, 1: 635-636 Meadow R 1992 Difficult and unlikeable parents. Archives Disease in Childhood 67: 697-702 Michele A A, Nielsen PM 1976 Tibiotalar torsion: bioengineering paradigm. Orthopedic Clinics of North America 7: 929-947 Morley A J M 1957 Knock knees in children. British Medical Journal 2: 976-979 Mosier K M, Asher M 1984 Tarsal coalitions and peroneal spastic flat foot. Journal Bone and Joint Surgery [Am] 66-A: 976-984 Napolitano C, Walsh S, Mahoney L et al2000 Risk factors that may adversely modify the natural history of the paediatric pronated foot. Clinics in Podiatric Medicine and Surgery 17(3): 397-417 Novacheck T F 1996 Developmental dysplasia of the hip. Pediatric Clinics of North America 43: 829-848 Ponsetti I V 1992 Current concepts review. Treatment of congenital clubfoot. Journal Bone and Joint Surgery [Am] 74-A: 448-454 Ponsetti I V 1996 Congenital clubfoot - Fundamentals of treatment. Oxford University Press, Oxford, pp 68-80 Ponsetti I V, Becker J R 1966 Congenital metatarsus adductus, the results of treatment. Journal Bone and Joint Surgery [Am] 74-A: 702-711
Reade E, Hom L, Hallum A et al 1984 Changes in popliteal angle measurement in infants up to one year of age. Developmental Medicine Child Neurology 26: 774-780 Reikeras 0, Hoiseth A 1989 Torsion of the leg determined by computerised tomography. Acta Orthopaedica Scandinavica 60: 330-333 Romanowski C A J, Barrington N A 1991 The accessory ossicles of the foot. The Foot 1(2): 61-70 Rose G K, Welton E A, Marshall T 1985 The diagnosis of flat foot in the child. Journal Bone and Joint Surgery [Br] 67-B: 71-78 Rushforth G F 1978 The natural history of hooked forefoot. Journal Bone and Joint Surgery [Br] 60-B: 530-532 Salenius P, Vankka E 1975 The development of the tibiofemoral angle in children. Journal Bone and Joint Surgery [Am] 57-A: 259-261 Sharrard W J W 1976 Intoeing and flat feet. British Medical Journal 1:888-889 Smillie I S 1969 Treatment of Freiberg's infraction. Procedures of Royal Society of Medicine 60: 29-31 Staheli L T 1993 Rotational problems in childhood. Journal Bone and Joint Surgery 75-A: 939-949 Staheli L T, Lippert F, Denotter P 1977 Femoral anteversion and physical performance in adolescent and adult life. Clinical Orthopedics 129: 213-216 Staheli L T, Chew D E, Corbett M 1987 The longitudinal arch. Journal Bone and Joint Surgery [Am] 69-A: 426-428 Svenningsen S, Tierjesen T, Auflem M 1990 Hip rotation and intoeing gait. Clinical Orthopaedics Related Research 251: 177-182 Tachdjian M 0 1972 Pediatric orthopaedics, 2nd edn, Vol 4. W B Saunders, Philadelphia, p 2826 Tachdjian M 01985 The child's foot. W B Saunders, Philadelphia Tax H 1985 Podopaediatrics, 2nd edn. Williams & Wilkins, Baltimore, pp 90-97 Thackeray C, Beeson P 1996a In-toeing gait in children: a review of the literature. The Foot 6(1): 1-4 Thackeray C, Beeson P 1996b Is in-toeing gait a developmental stage? The Foot 6(1): 19-24 Torpin R 1968 Fetal malformations caused by amniotic rupture during gestation. Charles C Thomas, Springfield Turner M S, Smillie I S 1981 The effect of tibial torsion on the pathology of the knee. Journal Bone and Joint Surgery [Br] 63-B: 396-398 Valmassy R L 1993 In: Thomson P (ed) Introduction to podopaediatrics. W B Saunders, London, pp 29-31 Wallander H, Hansson G, Tjernstrom B 1996 Correction of persistent clubfoot deformities with the Ilizarov external fixator. Acta Orthopaedica Scandinavica 67(3): 283-287 Waugh W 1958 The ossification and vascularisation of the tarsal navicular and their relation to Kohler's disease. Journal Bone and Joint Surgery [Br] 403-B: 765-768
FURTHER READING Berkow R (ed) 1987 The Merck manual, 15th edn. Merck Sharp & Dohme Research Laboratories
Behrman R E, Vaughan V C 1987 Nelson textbook of pediatrics, 13th edn. W B Saunders, Philadelphia
THE PAEDIATRIC PATIENT
Drennan J 1992 The child's foot and ankle. Ravens Press, New York Ferrari J 1998 A review of the foot deformities seen in juvenile chronic arthritis. The Foot 8(4): 193-196 Illingworth R S 1990 The development of the infant and the young child. Churchill Livingstone, Edinburgh McCrea J D 1985 Pediatric orthopaedics of the lower extremity. Futura, New York
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Pollak M 1993 Textbook of developmental paediatrics. Churchill Livingstone, Edinburgh Sharrard M D 1979 Paediatric orthopaedics and fractures, Vols I and II, 2nd edn. Blackwell Scientific, London Sheridan M D 1980 From birth to five years. Children's developmental progress, 7th edn. NFER-Nelson Publishing, Berkshire Thomson P (ed) 1993 Introduction to podopaediatrics. W B Saunders, London
CHAPTER CONTENTS
Introduction 373
Assessment of the sports patient
Guiding principles 373 Role of the sports podiatrist 374 Assessment environment 375
B. Yates
Injury risk factors 376 Intrinsic risk factors 376 Extrinsic factors 383 History taking 387 Medical history 387 Social history 388 Drug history 388 Sport history 389 Injury history 390 Examining the injured structure Specialist investigations 392 Injury grading systems 393 Summary 393
391
INTRODUCTION With increasing numbers of people undertaking regular exercise there has been a corresponding rise in the number of sports injuries. In 1991 it was estimated that there were 5 million cases of exercise-related morbidity in the United Kingdom (Nicholl et al 1991). This would equate to 1 in every 10 people sustaining one injury each year. With the profile of sport in society increasing, and the incentive of high salaries for professional sports men and women, it is likely that injury incidence figures are now even greater among the general population. Podiatry has a significant part to play in the management of sports injuries, as the majority of these injuries occur in the lower limb. The commonest acute injury is the ankle sprain (Colville 1998); the commonest tendon injury is to the Achilles tendon (Marks 1999) and the most frequently seen joint pathology is patellofemoral syndrome (Walsh 1994). Podiatric intervention is often an integral component in the successful management of these and other lower limb injuries.
GUIDING PRINCIPLES As with other areas of assessment it is essential to take an accurate history and perform a detailed examination. The majority of sports injuries seen by the podiatrist are chronic in nature due to overuse: they represent a diagnostic challenge due to the long injury period and compensation mechanisms which may have occurred as a result 373
374
SPECIFIC CLIENT GROUPS
of the injury. Both of these factors can make it difficult to confirm the diagnosis of the injury and ascertain its aetiological factors. The history and examination should be aimed at both diagnosing the injury and determining the presence or absence of intrinsic (personal) and extrinsic (environmental) risk factors associated with the injury. The identification of intrinsic and extrinsic risk factors can assist in making the diagnosis and guiding the management plan. It is important to gain as much information as possible about the injury. Information on the duration, nature, frequency and intensity of symptoms must be gained along with details of the injury mechanism, aggravating factors and previous treatment. Clinical examination of the patient, which should include the whole musculoskeletal system, with a specific focus on the lower limbs and the injury site, should follow the standard examination protocol of observation, palpation and movement. When turning to the injury site
it is imperative to know the anatomical structures of the region in order to make an accurate diagnosis. After observing the area for inflammation, erythema, ecchymosis, structural defects and malalignment the practitioner should physically examine the area. The purpose of the physical examination is to identify, isolate and then stress individual anatomical structures to try and reproduce the patient's symptoms. This should help enable the practitioner to identify whether the pathology is isolated to a specific tendon, ligament, bone, joint, muscle or nerve. A summary of the assessment process is given in Figure 15.1.
ROLE OF THE SPORTS PODIATRIST The podiatrist may be part of an interdisciplinary sports medicine team, a multidisciplinary sports medicine team or working as a sole practitioner. Central members of a sports medicine team are likely to include a sports physician, orthopaedic
Intrinsic factors Previous injurY,fitness, flexibility
Intrinsic factors Structural alignment, Flexibility, physical bulid
Extrinsic factors Sport, equipment, surface, training errors, environment
Extrinsic factors Equipment, sport technique
( Medical history Social history Drug history
,. !
i HISTORY
t
~
Injury history Location, duration, mechanism, Pain profile, +/- factors, previous treatment
IFFERENTIAL DIAGNOSIS
r
DEFINITIVE DIAGNOSIS
I Specialist investigations
Figure 15.1
(0
Injury observation Swelling, malalignment, ecchymosis, etc
Assessment of the sports patient.
)
Injury assessment Identify, isolate and stress injured structure
ASSESSMENT OF THE SPORTS PATIENT
surgeon, physiotherapist and podiatrist. Other members of the team may include a general practitioner (GP), radiologist, osteopath, chiropractor, podiatric surgeon, masseur, and professionals from the sports science disciplines such as an exercise physiologist, sports psychologist, and nutritionist. Working in such a team is of obvious benefit to both practitioner and patient. The patient is likely to be treated more holistically, with appropriate intervention more readily available. For the practitioner there should be assistance in making an accurate diagnosis and being able to treat more of the aetiological factors of the injury (Case history 15.1). Working as a sole practitioner is often more challenging. Assistance in making an accurate diagnosis through interdisciplinary discussion or access to specialist investigations such as magnetic resonance imaging (MRD bone scans and intracompartmental pressure tests may not be available. It is important to develop a referral network with other health care practitioners to
~~----~
----- - - - -----_._-
Case history 15_1 - - - - - - - - . - - - - - - - - - - - - - ----1
A 19-year-old female, elite cross-country runner with pain in her medial longitudinal arch was referred, by her coach, to a multidisciplinary sports medicine team. The pain had been present for 4 weeks and was gradually getting worse. The pain was centred around the navicular and the insertion of the posterior tibialis tendon was both prominent and painful. Base line X-rays were negative for a navicular stress fracture but demonstrated a type 2 os tibialis externum. A magnetic resonance imaging (MRI) scan was requested by the sports physician to examine the health of the tibialis posterior tendon and determine the presence of a stress fracture. The scan confirmed a navicular stress fracture and healthy tendon. She was treated with a short leg cast for 6 weeks followed by prophylactic orthoses to reduce pronatory compression forces on the navicular. She was also identified as being oligomenorrhoeic with only four menstrual cycles per year. This is known to be a risk factor for stress fractures (Tomten et al 1998). She was subsequently referred for dual energy X-ray absorptiometry (DEXA) scanning of her pelvis, spine and foot, which demonstrated reduced bone mineral density. She was therefore referred to a gynaecologist and sports nutritionist to address these imbalances. Three years on she is still competing at an elite level and has had no further stress fractures.
375
overcome these potential shortcomings and to be able to offer the patient more beneficial treatment plans. If such a network does not exist the practitioner may be required to provide treatment and advice using mechanical, physical and pharmacological modalities as well as giving advice on appropriate training schedules. Although this may not affect the treatment outcome, the practitioner must be aware of his limitations and refer to other practitioners where necessary.
ASSESSMENT ENVIRONMENT The practitioner may assess and treat the injured athlete in a variety of different environments: the majority are likely to be in a clinic or private practice setting, whereas practitioners involved with sports clubs will often see athletes in whatever medical facilities are available at the club ground or stadium. Some athletes may require assessment and treatment at the side of a pitch or track during an event. In each situation there will obviously be time, space and equipment limitations. A methodical, well-planned and logical approach to the assessment will assist the practitioner in whichever environment he is treating the athlete. As with any biomechanical examination it is important to have an area to observe the athlete's gait. There should be a minimum of 5 m of uninterrupted non-carpeted surface. A flat bed couch is essential for a number of tests where the athlete must be able to lie fully prone, supine or on their side. There should be plenty of space on either side of the couch for the practitioner to undertake an assessment of the knee, thigh, hips and lower back. Tape, padding and temporary orthoses are useful adjuncts to diagnosis and should be available in all working environments. It is important that the athlete wear clothing that permits an accurate examination. Shorts must be worn to allow assessment of the knees and observation of leg alignment and muscle bulk. It may be of benefit to have spare shorts of different sizes available for patients who do not bring their own. Jumpers and jackets should be removed to
376
SPECIFIC CLIENT GROUPS
assess the spine, hips and shoulder position. Assessment of the athletes' footwear is essential. This should involve both the sports footwear and general footwear, as either or both can contribute to overuse injuries. Athletes should be advised to bring their sports shoes to all consultations. The use of gait analysis equipment can be of great benefit in assessing the sports patient. The most commonly used equipment is a treadmill, with or without the use of a video camera. More specialist equipment such as force platforms, inshoe pressure systems and digitised video gait analysis are discussed in detail in Chapter 12. Specialist equipment can be very useful when assessing more complex sports injury cases or when treating professional athletes. These systems can: • • • •
aid the diagnosis identify sporting technique assist in treatment planning help explain injury mechanisms to the patient.
Although the cost would prohibit most practitioners from purchasing such equipment it would be beneficial to identify where patients can be referred for this type of analysis.
INJURY RISK FACTORS The aetiology of both acute and chronic injuries is undoubtedly multifactorial. To simplify this process, risk factors are divided into intrinsic and extrinsic causes. Intrinsic risk factors are those that are personal and are either biological or psychosocial characteristics that predispose the individual to injury. Intrinsic risk factors account for up to 40-60% of all running injuries (Cavanagh & Kram 1990, James et al 1978). Extrinsic risk factors are independent of the person and are related to the type of sporting activity and the sporting environment. Extrinsic risk factors account for up to 80% of running injuries (McKenzie et aI1985). Of all risk factors for overuse injuries training errors are the most common and may account 60% of the cases (Hreljac et al 2000). Table 15.1 lists the intrinsic and extrinsic risk factors to injury.
Table 15.1 Intrinsic and extrinsic risk factors associated with sports injuries
Intrinsic risk factor
Extrinsic risk factor
Age
Sporting equipment
Gender
Exercise surface
Previous injury
Sporting activity
Structural alignment
Sport position
Flexibility
Training errors
Physical fitness
Warm up and stretching
Physical build
Environmental factors
Psychological factors Systemic disease
Intrinsic risk factors Age
The age of an athlete can affect both the type of injury that may occur and the healing mechanisms that follow. Younger and older athletes tend to be more injury prone for a variety of reasons. There is generally less muscle mass and muscle strength in both of these groups compared with older adolescents and young adults. This can result in greater injury risk both in contact and endurance sports. Less protective sports equipment is available for children than adults, which can lead to greater injury risk from ground reaction forces and physical contact. The quality of coaches in children's teams is often lower than their adult counterparts, which may cause injury due to improper training and coaching supervision (Dalton 1992). In children of all ages fractures are more common than ligamentous disruptions. Even the location of fractures varies with the age of the child. Adolescents tend to have fractures in the physeal areas, whereas preadolescents have more fractures in the diaphysis (Cantu & Micheli 1991). Certain bony injuries, such as the osteochondritides, can only occur in the young athlete. Also traction apophysitis of the calcaneus (Sever's disease), the fifth metatarsal (Iselin's disease), and of the tibial tubercle (Osgood-Schlatter's disease) only occur in children and adolescents, although rarely the symptoms may persist into adulthood
ASSESSMENT OF THE SPORTS PATIENT
377
._--------------_._-- .._---_._--_._---_._-_ .. _ - - _ . _ - - - - - - - - - - - _ . _ - _ . -
in the case of Osgood-Schlatter's disease. Both traction apophysites in the young athlete and musculotendinous injuries in the older athlete have been linked with reduced flexibility. It is known that reduced flexibility is more common in both groups (Anderson & Burke 1994, Gerrard 1993). Assessment of flexibility is therefore a key area when examining both children and older athletes with sports injuries. Musculotendinous injuries are the commonest injury in the older athlete (over 40 years). This is due to a number of cellular changes which occur with increasing age. Changes in collagen crosslinking cause an increase in tendon stiffness and reduce the elasticity of the tendon. This can result in a muscle being subject to earlier and prolonged loading in a movement cycle and being unable to undergo normal stretching, resulting in damage to the musculotendinous unit. The diameter, density and cellularity of the collagen fibrils are also diminished with advancing age, which results in reduced muscle mass and strength. Finally, the blood supply to tendons reduces with age, resulting in an increased risk of tendonitis, tendonosis or rupture (Strocchi et aI1991). Overuse injuries in the older athlete may also develop due to a delayed physiological response to exercise. When a person starts an exercise programme there are gradual positive changes to the cardiovascular, neurological, endocrine and musculoskeletal systems. As a person becomes fitter the muscles become stronger and there is an increase in bone density. These normal adaptive changes are delayed in the older athlete and may cause musculotendinous injuries if the athlete increases their training volume too quickly. Gender
Physiological differences between the sexes result in differences in athletic performance. For comparative body sizes women have a reduced cardiac output, blood volume, vital capacity and mean muscle mass when compared to males. Whether this increases the risk of injury in female athletes is uncertain. Studies involving civilian populations have not shown significant differences in injury rates between the sexes; except in children where
boys are twice as likely to be injured as girls (Bruns & Maffulli 2000). This is in contrast to studies involving military personnel where injury rates among female recruits are between two and four times higher than their male counterparts (Jones et a11988, Ross & Woodward 1994). Perhaps of more significance than injury rates are the differences in the types of injury seen between males and females. Certain injuries are associated with certain sporting activities. An example of this is posterior ankle impingement, which is most commonly seen in females participating in either dance or gymnastics. Pain from existing structural deformity or natural alignment may also occur in the female athlete. Hallux valgus is far more common in females and the joint or prominence can become painful due to the increased ground reaction and frictional forces of sporting activity. A valgus alignment of the knee is more common in females, and this can increase the strain on the medial soft tissue structures of the knee during sport involving excessive knee flexion and rotation, e.g. medial collateral ligament injuries in skiing. Patellofemoral syndrome is undoubtedly more common in females than males and this is probably due to a wider pelvis decreasing the mechanical efficiency and altering the muscle mechanics of the patellofemoral joint. The incidence of stress fractures has also been reported to be higher in females. Early studies showed the female incidence to be 10 times greater than men (Protzman & Griffis 1977). Although more recent studies have not shown such a significant difference between the sexes it is generally accepted that female athletes are more prone to stress fracture than males, especially in the military. There are three common aetiological factors which may be responsible for this greater relative risk of stress fracture. These interlinking factors are known as the female athlete triad or unhappy triad and are usually present in combination: • amenorrhoea or menstrual irregularities (less than five menses per year) • osteoporosis (due to menstrual abnormalities, hormonal imbalance, calcium deficiency or malnutrition)
378
SPECIFIC CLIENT GROUPS
------'-'--'-'--
• eating disorders (anorexia nervosa, bulimia nervosa, binge-eating disorders, anorexia athletica). Although any of these factors can be present in the non-athletic female population both amenorrhoea and eating disorders are more common amongst athletes. One prospective study also demonstrated that stress fractures occurred more frequently in female athletes with low bone density (Bennell et al 1996). It is generally agreed that females are more flexible than males. Whether this should affect injury rates between the sexes is unclear, but it has been reported that greater flexibility may predispose ligament injuries whereas inflexibility may predispose musculotendinous injuries. This would result in females being more prone to ligament injuries and males to musculotendinous injuries. Some evidence would appear to support this theory, as both anterior cruciate knee ligament injuries and lateral collateral ankle ligament injuries have been reported to be higher in females than in males undertaking the same activity (Almeida et a11999, Griffin 1994).
changes may be in proprioception or neuromuscular coordination resulting in excessive strain on adjacent or distant structures (Case history 15.2). Structural alignment
The assessment of structural alignment must include an overall impression of the whole body, with a specific focus on the lower limbs and the injured area. The purpose is to assess and determine if the body's structure and function has caused or contributed to the injury. Biomechanical abnormalities may be identified, but their relevance to injury must be determined. It is also important to determine if any abnormality has occurred due to the injury rather than causing it. Structural alignment should be assessed with the patient non-weightbearing, weightbearing and dynamically. A thorough examination in all three components is essential if the practitioner is to gain a complete picture of the athlete's structure and function as it relates to the injury. This ,-.------ - - - - '----------------1
Previous injury
History of previous injury is a common finding when assessing the injured athlete. The relative risk of developing an injury when a history of a previous injury is present is two to three times greater than with a history of no injury. The majority of studies in this area have involved military subjects or runners. It is not surprising that a previously traumatised structure may be re-injured, as the athlete may frequently return to exercise too quickly or the underlying cause of the injury has not been addressed. The subsequent injury is often more severe than the previous injury. An example of this is seen in tibial stress fractures, where there is a history of previous exercise-induced shin pain in up to 50% of cases. The subsequent injury does not necessarily occur at the same location as the previous injury. This may suggest compensatory changes have occurred due to the injury or its treatment. These
IL
Case history 15.2
_
A zs-year-olc male, international rugby player was diagnosed with right-sided Achilles tendonosis. The pain in the tendon had been present for 2 months and had caused him to reduce his training volume. It had not improved with physiotherapy. The tendon was painful on palpation 4 cm proximal to its insertion and there was moderate swelling. There was a history of right-sided plantar fasciitis that had resolved 8 months ago with calf stretches, strapping and physical therapies. All non-weightbearing and static biomechanical parameters, inclUding limb length, were the same for both limbs and calf flexibility was excellent in both limbs. Dynamic video gait analysis with the athlete running on a treadmill demonstrated an earlier heel lift on the right side. Video analysis taken prior to both injuries was used as a comparison and did not demonstrate an early heel lift. It appeared that due to the previous plantar fasciitis the athlete had adapted his gait by an early heel lift in an attempt to reduce the impact forces acting on the heel. This had resulted in excessive muscle activity of the calf muscle, inducing the tendonosis. The athlete was successfully treated with gait re-education and a heel raise in his sports footwear that was gradually reduced over a 3-month period.
i
ASSESSMENT OF THE SPORTS PATIENT
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assessment should include examination of the joints, muscles and osseous alignment (Ch. 8). The majority of podiatric interventions in sports injuries are related to the assessment and treatment of structural alignment and function that has caused or contributed to the injury. Chronic or overuse sports injuries are usually due to the presence of one or both of the following situations:
• muscle weakness (vastus medialis, gluteus medius, medial retinacula of the knee) • patella malalignment or hypermobility (in frontal, transverse or sagittal plane) • patella maltracking (during flexion and extension) • excessive subtalar joint pronation • frontal plane malalignment of the knee or tibia.
• normal structure and function but inadequate preparation or excessive demands placed on the tissues • abnormal structure and function with relatively normal demands placed on the tissues.
The presence or absence of these factors should assist the practitioner in identifying the aetiological factors and planning the most effective treatment (Witvrouw et al 2000). Asymmetries between limbs may represent the obvious cause of a unilateral overuse injury. However, it is important to consider the role of other factors such as the type of activity, exercise surface, unilateral trauma and injury history. Any of these factors may cause a unilateral injury. If structural asymmetry is identified, then the practitioner must determine a biomechanical mechanism by which the asymmetry could have caused the overuse injury. If we consider stress fractures as an example, there is a strong association between stress fractures and limb-length inequality (Brukner et al 1999). Stress fractures tend to occur in the longer limb, and the greater the inequality the greater the incidence (Friberg 1982). The reasons for this are thought to be due to the biomechanical consequences of the limblength difference, which results in a longer stance phase, skeletal realignment, greater osseous torsion and increased muscle activity of the longer limb.
Although this is a rather simplistic view, it can be seen to be true in the majority of cases. If we consider two runners with patellofemoral syndrome: runner A runs over 100 miles/week, running every day; runner Bruns 20 miles/week, running 3 times per week with 4 rest days. Apart from their injuries, they are both healthy and have taken 6 months to get to this weekly mileage. It should be clear that runner A is doing too much, too soon, and too frequently: • running 100 miles/week will often result in injury • a running volume of 100 miles/week in just 6 months has not allowed the tissues to undergo the normal adaptive processes required to meet these demands • running every day does not allow adequate recovery time for the tissues, resulting in injury. Other aetiological factors may also be present in runner A, but treatment will fail unless the errors of the training schedule are addressed. In the case of runner B, the aetiology of his injury is likely to be due to abnormal structure and function which has resulted in excessive patellofemoral joint reaction forces. His structural assessment should include examination of factors such as: • muscle inflexibility (hamstrings, iliotibial band, quadriceps, lateral retinacula of the knee and calf muscles)
Flexibility
Hypermobility due to increased muscle flexibility and ligamentous laxity has been associated with a greater risk of injury. Hypermobility is often determined by the Beighton score, which is based on a nine-point test designed to measure excessive joint movement (Ch. 14). This test has been used in a number of studies on flexibility and injury, which has generally shown that hypermobility is associated with a greater incidence of ligamentous injury. Rossiter & Galbraith
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(1996) found that hypermobility was present in 34% of military recruits with ankle and knee ligament injuries compared with 19% of control subjects. Increased flexibility, measured by the sit and reach test, in the absence of ligamentous laxity has not been shown to be a significant factor in injury prediction. Generalised inflexibility due to muscle tightness has been linked to musculotendinous injury: while this is likely to be true, it has not been proven in any long-term prospective study. However, if a theoretical causal link can be made between the muscle inflexibility and the injury, then stretching of those muscles should be included in the treatment programme. Likewise, if hypermobility is present, then stretching should be avoided and athletes encouraged to perform specific stabilising exercises. Stretching prior to activity does not appear to reduce the risk of lower limb injury. This has been demonstrated in a number of studies, including two large randomised controlled trials involving military recruits (Pope et a11998, 2000). These studies did not measure the level of flexibility of the two groups but demonstrated that the injury incidences of the two groups were the same irrespective of whether the athlete stretched or not prior to exercise. This does not mean that injured athletes with muscle inflexibility should not be instructed to stretch, as this is an effective treatment modality. However, athletes are often questioned as to whether they stretch before and after activity and encouraged to do so if they do not. There seems little evidence to support this premise and failure to stretch before exercise should not be viewed as a risk factor to injury. Physical fitness
Physical fitness is known to lower the risk of injury, as shown in a number of studies based on military and civilian populations (Neely 1998). This protective mechanism not only applies to practising a known sport but also to learning a new sport or athletic skill. The level of reduced risk varies amongst the studies, and is dependent upon the activity being undertaken and the
fitness test used. Pope et al (2000) were able to demonstrate that the least-fittest group of their army recruits were 14 times more likely to sustain a lower limb injury than the fittest group. The fitness method used was the progressive 20 m shuttle run test, also known as the bleep test. This test is one of the most popular fitness tests used today. When assessing injured athletes it is important to gauge their fitness level, as you may need to offer advice on a more appropriate training regimen. This is often the case for the novice athlete who enthusiastically embarks on an overambitious fitness programme. This will result in injury, as the musculoskeletal system is not prepared for such strenuous exercise. When an injury occurs, the athlete should be advised to modify his exercise to prevent recurrence or further injury to other structures. This advice may include changing the method of exercise or reducing the intensity, frequency or duration of the exercise. Physical build
The relationship of physical strength to injury is unknown. To avoid injury the musculoskeletal system must be able to cope with the physical demand of the sporting activity. Some evidence suggests that stronger athletes are more injury prone (Knapik et aI1992). The reasons for this are unclear, but it may be that the muscular forces generated by stronger athletes damage their joint structures and even the muscles themselves. It may also be that stronger athletes exercise at greater intensity or duration than weaker athletes, resulting in higher injury rates. There is a correlation between strength imbalance and injury that is most frequently seen in the knee joint, where differences between hamstring and quadriceps strengths have been associated with cruciate ligament injuries. The role of strength differences between limbs has also shown a greater injury incidence on the weaker side. There is general agreement that strength differences greater than 10% can increase the injury risk to the weaker limb. These injuries may be acute, as with cruciate ligament injuries, or
ASSESSMENT OF THE SPORTS PATIENT
chronic, due to fatigue, e.g. tendonitis, muscle strains and stress fractures. The role of limb dominance in injury incidence is less certain. Limb dominance in racket or ball sports is associated with different injury patterns. However, in sports that require equal stresses through both limbs there is no evidence to suggest limb dominance is a risk factor. Herring (1993) was unable to show any difference in injury incidence based on limb dominance in elite runners. Anthropometric data such as height, weight, body mass index (BM!) and total body fat have also been examined as injury risk factors. In general, it is only the BMI that has been shown to be a positive indicator for injury risk. The BMI is determined by dividing the body weight in kilograms by the height of the patient in metres squared (i.e. kg zm"). The normal BMI range is 20-25 with above 25 representing clinically overweight, above 30 clinically obese and below 20 representing underweight. As a general rule, the injury risk doubles for individuals who fall outside the normal BMI range. Psychological factors
Psychological factors can playa significant part in both the development of a sports injury and the rehabilitation of the injury. Although there is no definite psychological profile of the injuryprone athlete, there are certain characteristics which may predispose the athlete to injury. Acute injuries may be more frequently seen in athletes who are extroverts with a low sense of responsibility. These athletes are natural risk-takers who may put themselves in injurious situations unnecessarily. The reasons for this type of sporting behaviour may be due to a daredevil attitude, poor decision making or an attempt to gain popularity with their peers, coach or supporters. Chronic overuse injuries may be seen more frequently in athletes who demonstrate high levels of responsibility and dedication. These athletes will often train and play beyond the point of fatigue, resulting in small repetitive trauma to the tissues. This can cause chronic overuse injuries such as stress fractures, tendonitis and muscle strains.
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Other obvious psychological injury risk factors are stress and anxiety levels. Stress may come from the sport itself or other life stresses. Changes in personal circumstances, careers and relationships with family and friends can induce significant stress on an athlete. The athlete may then view sport as an escape or outlet to vent frustration, which can lead to poor decision making and injury. It is important to be aware of these factors when treating the athlete, as injury recurrence will be high if they are not addressed. This may mean liaising with the athlete's coach or team physician, so that an appropriate social support network can be provided. The psychological response of the athlete to an injury can vary significantly. Most will go through a reaction of stress and grief. The grief response to an injury is like a minor or moderate version of losing a loved one. The severity of the injury and the importance of sport to the athlete will determine the level of the grief response. The grief response is characterised by three phases: Phase 1 - shock. The immediate response to the injury may be one of sudden complete shock. The athlete may show signs of anger, disbelief and deny the existence of the injury. Rehabilitation of the athlete cannot begin until this phase is over. Phase 2 - preoccupation. The athlete may demonstrate signs of depression and guilt about the injury, becoming isolated from other team members, family and friends. The athlete may also show signs of bargaining behaviour when undergoing treatment during this phase. Rehabilitation may begin during this phase, but real progress will not be achieved until the athlete enters the next phase. Phase 3 - reorganisation. This is characterised by the athlete fully accepting the presence of the injury and demonstrating a renewed interest in the rehabilitation programme. The athlete is also likely to show a renewed interest in the sport and in relationships with family and team-mates. The practitioner should be aware of the various emotional states the athlete may demonstrate. This can help in formulating more appropriate treatment plans with one of the
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main aims being to guide the athlete to the final reorganisation phase. Systemic disease
Practitioners must be aware that not all athletes are free from systemic disease or medical conditions. Cardiovascular, respiratory, endocrine, arthritic and neurological complaints are seen fairly frequently in the athletic population. The spur for many people to start to exercise may be the presence of hypertension, cardiovascular disease or obesity. Patients with systemic disease are often prescribed exercise programmes by other medical professionals such as CPs, medical consultants or physiotherapists. The role of exercise and sport is generally beneficial for patients with systemic disease as it can improve cardiovascular, respiratory and neurological function and help improve strength, flexibility and mobility. However, the exercise must be of the right type, intensity, duration and frequency to ensure medical complications do not arise. Practitioners should also be aware that undiagnosed systemic disease may be the underlying cause of the injury (Case history 15.3).
Patients with cardiovascular conditions such as peripheral vascular disease or hypertension must exercise with caution. Dynamic exercise increases the cardiac output, increases the blood flow to working muscles and causes peripheral vasodilation. The net result is a rise in systolic pressure in normotensive athletes. However, with hypertension there are rises in both systolic and diastolic pressures from already elevated baseline levels. This can elevate the blood pressure to dangerous levels, particularly if the athlete has moderate to severe hypertension, the exercise intensity is too high or isometric exercise is performed. In patients with vasospastic conditions or peripheral vascular disease, localised tissue hypoxia can result if the metabolic demands of the exercising tissues are greater than the blood supply can provide. It is also important to remember that certain sports injuries are caused by cardiovascular changes such as acute and chronic compartment syndromes of the lower leg and foot, and popliteal artery entrapment syndrome. Exercise can also occasionally be the cause of cardiovascular pathology, such as effortinduced deep vein thrombosis or external artery endofibrosis (Bradshaw 2000).
Case history 15.3 A 38-year-old male physical education instructor was referred by his GP with a 2-month history of localised pain in both forefeet. The patient was otherwise healthy and participated in a wide variety of sports both at work and socially. Both he and his GP were unsure of the nature of his pain and he had been referred for further investigation and orthotic treatment if appropriate. A thorough medical history demonstrated no major illnesses, operations or a history of lower limb injuries. There was no significant family medical history or social history. There was also no recent history of a change in exercise pattern or footwear. The pain was centred around the left fifth and right third metatarsophalangeal joints and tended to occur after activity. The pain was gradually getting worse. Moderate swelling was present at both joints, particularly in the right second interspace, with slight splaying of the second and third toes (Sullivan's sign). A list of differential diagnoses was considered, includinq stress fracture, capsulitis, synovitis, flexor digitorum longus tendonitis, neuroma, bursitis, soft tissue mass (right foot only), osteoarthritis
and systemic joint disease. After a thorough clinical examination osteoarthritis, stress fracture and tendonitis were excluded. The examination of the joints caused pain and there were some neuritic symptoms in the right foot. The patient was given a local anaesthetic injection into the web space to exclude a Morton's neuroma and a temporary orthosis. The patient was also referred for X-ray. Upon review the local anaesthetic injection had not resolved the symptoms but the temporary orthosis had alleviated some of the pain. The X-rays revealed erosive changes in both metatarsal heads and the patient was subsequently diagnosed by a rheumatologist as having rheumatoid arthritis. The patient is currently taking disease-modifying drugs, wearing appropriate orthoses and continues to exercise. His exercise programme has been modified to avoid high-impact and contact sports. This case demonstrates the importance of keeping an open mind when determining the diagnosis of an injury. Practitioners should consider all potential causes to avoid unnecessary or inappropriate treatment.
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Athletes with diabetes must monitor their blood glucose levels very closely, especially when starting or altering an exercise programme. Exercise increases the demand for glucose in the exercising tissues, resulting in a sharp drop in blood glucose levels. This can trigger a hypoglycaemic attack. Athletes will often have to reduce their dosage of insulin before exercise and should always have a ready source of glucose available when they exercise. It is important that diabetics exercise to help reduce cardiovascular complications and limited joint mobility associated with the disease. Neurological conditions such as upper or lower motor neurone lesions, hereditary motor and sensory neuropathies and nerve entrapments may occur in athletes. Patients with neurological disorders are often advised to exercise. Such patients may have altered sensation, altered muscle function and gait and a pes cavus foot deformity. These patients must be carefully assessed to ensure they undertake the appropriate exercise programme using appropriate supports as required. Avoidance of high-impact and contact sports is essential in neuropathic patients.
systems' or special air or gel pockets to aid shock absorption is often used to market the brand as being better than that of the competition. The evidence to support such claims is often lacking. The practitioner should appraise the athlete's shoe, identifying good and bad attributes and, if recommending a change in footwear, advise the athlete of what to look for when buying new sports shoes. To recommend one specific model for all patients will fail, as many patients will return dissatisfied if the injury does not resolve or complain that the shoe is uncomfortable. The aim for the practitioner is to ensure that the patient is exercising in a shoe that is:
Extrinsic factors
Many sports shoes do not meet all of these criteria and can playa significant part in the development of an overuse injury. Worn shoes have been identified as risk factors in the incidence of a number of injuries such as stress fractures, exercise-induced leg pain and Achilles tendonitis due to a lack of shock absorption (Gardner et a11988, Myburgh et al 1988). The shoe is the interface between the foot and the ground and must absorb significant ground reaction forces generated by sporting activity. As the shoe ages or becomes more worn, its ability to absorb these forces is reduced, resulting in increased forces being passed on to the musculoskeletal system. It has been estimated that the average running shoe loses 50% of its shock-absorbing capabilities after 300-500 miles of running (Cook et al 1985). Old shoes may not only demonstrate signs of excessive wear but also material degradation can occur, even further reducing the shock-absorbing capabilities of the shoe.
Sporting equipment
The most important piece of sporting equipment in the assessment of chronic overuse injuries is the athlete's footwear. The athlete's shoes can assist in the diagnosis of the injury as they are often a contributory aetiological factor. They also represent an adjunct to treatment, as the practitioner will often modify the footwear or use it to accommodate an orthosis. In certain circumstances the practitioner may recommend changing the footwear completely. Recommending the right shoe for the patient is not easy. Sports shoe manufacturing is a multi-billion pound industry and company research data on shoe design and function are closely guarded secrets. Each company produces a number of different models for the same sport making it hard to know which is the best one. The most expensive model does not mean it is the best. The use of 'motion control
• • • • • • • • •
comfortable correct fit in length and width appropriate for the patient's sport does not show signs of excessive wear has appropriate tread, studs, spikes, cleats for the sport and exercise surface provides sufficient shock absorption, especially in the midsole provides appropriate motion control for the patient firm fastening lightweight.
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An uneven wear pattern on the sole of the shoe or the insole inside the shoe can give a guide to biomechanical abnormalities or sporting technique of the athlete. Excessive lateral wear of the rearfoot can indicate a varus alignment or strike pattern and may cause inversion ankle sprains or lateral foot and leg injuries. Excessive wear across the ball of the foot will cause a loss of traction and control, which may induce injury. Different wear patterns between the shoes may indicate different biomechanics or sporting technique. The most common example of uneven wear is limb-length inequality due to structural, functional or environmental factors. The weight of the shoe is important to optimise performance: the heavier the shoe, the greater the muscle exertion and energy expenditure. This can cause fatigue in the lower leg muscles and therefore affect performance. Light running shoes may enhance speed but should only be worn for racing as they do not offer appropriate support or shock absorption. The importance of comfort and correct fit cannot be overstated. Shoes that are too tight or narrow will obviously cause irritation, resulting in corns, calluses, subungual haematomas and other nail pathologies. It is common in kicking sports such as soccer and rugby that the athlete will wear a boot that is too small in order to get a better 'feel' for kicking the ball. This practice should be discouraged as it can often lead to clawing of the toes and exacerbate nail pathologies. Shoes that are too narrow or fastened too tightly can cause pain in the arch and neuritic pain in the forefoot during exercise. A shoe that is too long will allow excessive movement of the foot, resulting in friction blisters and heel slippage. Exercise surface
The role that the exercise surface may play in the development of overuse injuries is a contentious issue. It was previously thought that athletes who exercise on hard unyielding surfaces such as concrete would have an increased incidence of osteoarthritis due to accelerated wear and tear of the joints. There is very little evi-
dence to support this despite several long-term prospective studies. However in athletics, harder synthetic track surfaces can increase performance but also increase the incidence of musculoskeletal injury. If athletes exercise solely on hard surfaces, increases in the incidence of medial tibial stress syndrome by 28% and Achilles tendonitis by 17% have been demonstrated (Nigg & Yeadon 1987). Artificial grass was first used for sport in 1964 and has since become a major playing surface in a wide number of sporting activities. The injury profile of this surface is different to that of natural grass. Bowers & Martin (1976) identified an injury virtually unique to this surface. Turf toe is a hyperextension injury of the first metatarsophalangeal joint resulting in a sprain of the plantar capsuloligamentous structures. It is caused by shoes with a flexible sole in the forefoot bending excessively on a hard unyielding surface. It is primarily seen in American football but can occur in any sport played on artificial grass surfaces such as AstroTurf. Harder surfaces invoke greater ground reaction forces, which must be absorbed by the shoe and musculoskeletal system. The body absorbs these forces primarily through the joints and eccentric muscle activity. The harder the exercise surface, the greater the eccentric muscle activity (Richie et al 1993). Theoretically, exercising on harder surfaces should cause greater knee flexion, ankle dorsiflexion and greater or prolonged subtalar joint pronation to aid the absorption of the higher ground reaction forces. No biomechanical studies have shown this to date. In addition to the hardness of the exercise surface, it is important to consider the friction and energy loss of the surface. Friction, or horizontal stiffness, is integral in acceleration and deceleration. Artificial athletic surfaces have greater friction than grass, allowing greater acceleration and deceleration. However, these greater frictional forces must be absorbed by the body and can result in increased injuries. These injuries may be to the musculotendinous units or the ligaments designed to limit joint movements such as the cruciate ligaments of the knee.
ASSESSMENT OF THE SPORTS PATIENT
Energy loss of a surface is related to its elastic behaviour and deformation properties. Surfaces that deform when loaded are termed compliant and result in increased contact time. This increases cushioning as peak contact forces are reduced. However, it may reduce performance as the contact time is greater, resulting in slower acceleration. Exercising on softer surfaces can also alter joint positions. Consider an athlete running on sand. The greatest contact force occurs at heel strike, so the sand will be maximally displaced at this time. This results in greater ankle dorsiflexion, requiring greater muscle activity of the calf muscles. Thus, exercising on softer surfaces may reduce injuries associated with high-impact forces but may lead to increases in muscle activity resulting in musculotendinous injury. It is also important to consider the terrain and incline of the exercise surface. Uneven terrain such as grass will mean the body having to adapt to maintain ground contact and stability. These adaptive changes mainly occur in the frontal plane and can result in greater supinatory and pronatory moments within the foot and ankle. If these forces become excessive then frontal plane injury will result. The most obvious example of this is the inversion ankle sprain. Pronatory injuries can occur and usually involve the posterior tibial tendon. If an athlete exercises on uneven terrain with frontal plane movements of the foot and ankle limited by strapping, a brace or boots, then greater forces will be transferred to the knee. This can result in collateral ligament and cruciate damage. This injury pattern has been seen in skiing. Uneven terrain can also exist on surfaces which are perceived to be flat. The camber of roads is usually canted up to 14°. This can cause pronatory moments on one limb and supinatory moments on the other, resulting in an environmental limb-length difference. The importance of exercising on an incline should not be overlooked. Both uphill and downhill running are associated with different joint angular relationships and muscle activity patterns. Uphill running requires greater ankle joint dorsiflexion and eccentric calf and ham-
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string muscle activity. Downhill running requires greater ankle plantarflexion and eccentric muscle activity of the foot dorsiflexors. This particularly affects the tibialis anterior muscle, which becomes active for longer and elongates further as it decelerates foot slap. Downhill running also increases the load on the quadriceps muscles and is known to exacerbate conditions such as patellofemoral syndrome and patella tendonitis. Sporting activity
The type of sport the athlete plays and the techniques they use are integral to the development of overuse injuries. Certain injuries are even named after certain sports or activities (Table 15.2). This does not mean that these injuries are unique to that particular sport, but they occur frequently due to the forces the anatomical structure has to absorb. Metatarsal stress fractures are not unique to military personnel who march, but this activity involves repetitive impact forces through the forefoot, which can result in a stress fracture. Patella tendonitis is most commonly seen in jumping sports due to the high ground reaction forces (up to eight times body weight) that this activity produces. A significant component of these forces is absorbed by eccentric quadriceps activity, which can cause patella tendonitis.
Table 15.2
Common injuries named after a sport
Injury name
Injury definition
Footballer's ankle Tennis leg
Anterior ankle impingement Rupture/tear of medial head of gastrocnemius
Fresher's leg
Exercise-induced shin pain
March fracture
Metatarsal stress fracture
Jumper's knee
Patella tendonitis
Runner's knee
Patellofemoral syndrome
Golfer's elbow Tennis elbow
Medial epicondylitis Medial (forehand) epicondylitis, lateral (backhand) epicondylitis
Swimmer's shoulder
Rotator cuff pathology
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It is important the practitioner has an understanding of the type of sport the athlete plays and its biomechanics. This will help the practitioner:
• understand the forces involved in the sport • identify the structures at risk of injury • determine the potential biomechanical mechanism of injury • formulate the most appropriate treatment plan. These four factors are all interrelated. Identifying the structures most at risk of injury requires knowledge of the forces involved in the sport. This knowledge is related to the biomechanical movements of that particular sport. Determining the biomechanical mechanism of injury is crucial to formulating the most appropriate treatment plan. Without this knowledge it is difficult to reduce or prevent the forces that caused the injury. Appropriate treatment planning must also take into account the limitations of the sport on the treatment. This will include the athletes' footwear and other sporting equipment. Some sports do not allow the use of mechanical supports as they may compromise player safety or give the athlete an unfair advantage. It is also important to be aware of individual variation in sporting technique, which not only determines the athlete's skill and ability at a sport but can also predispose injury. Minor differences in sporting technique can have a significant effect on injury development. An example is in running techniques between forefoot and rearfoot strikers. Forefoot striking is associated with increased impact forces, a reduced stance phase and reduced subtalar joint pronation. These three factors combined could increase the forces being absorbed both in the forefoot and more proximally in the calf muscles, shin and knee. The team position will also help determine the sporting technique of the athlete. The position played may be based on anthropometric characteristics, limb dominance and skill levels. Team position may be important to the practitioner, as the biomechanical movements and sporting techniques used by the athlete can vary.
This will result in different injury profiles seen between positions: e.g. a prop forward and wing back in rugby, a wicket keeper and fast bowler in cricket, a linebacker and wide receiver in American football. Training errors
As discussed earlier, athletes may do too much, too soon, and too frequently. Training errors are one of the commonest causes of chronic overuse injuries, and practitioners must identify these errors for successful treatment planning. Failure to do so will lead to a recurrence of the injury or development of other overuse injuries. To avoid injury athletes who wish to exercise regularly must find the correct balance of exercise intensity, duration and frequency. This will normally involve: • participating in more than one sport • combination of strength, flexibility and endurance training • incorporation of rest days in the weekly training schedule • periods during the year of greater training/sport levels, i.e. seasons • variation in training methods to help maintain interest. When athletes first begin to train they often overestimate their baseline fitness level. This can result in injury, as the musculoskeletal system is not physiologically prepared for this volume of exercise. Common injuries at this stage are muscle strains and exercise-induced leg pain (shin splints). Increasing the volume of exercise too quickly can also occur when an athlete is returning from injury or training for a specific competition that they are not prepared for. Bones, like muscle, also undergo a normal physiological strengthening process during the early period of an exercise programme. This remodelling process is characterised by initial bone porosity due to osteoclastic channelling, which is then followed by osteoblasts laying down new bone matrix. The result is that the bone is initially weakened by exercise and then eventually strengthened beyond its pre-exercise level.
ASSESSMENT OF THE SPORTS PATIENT
This whole process usually takes 6 months and during the first 2 months the bone is especially prone to injuries such as stress fracture. This is one of the main reasons stress fractures are usually seen during the first 2 months of starting an exercise programme or significantly increasing the exercise level (Beck 1998). Environmental factors
Changes in temperature, humidity and altitude can all affect performance and may increase injury risk. Practitioners providing treatment at endurance events should be particularly aware of the consequences of environmental factors. High temperatures and humidity levels can produce heat-intolerance illnesses including syncope, heat cramps, exhaustion and stroke. These are most frequently seen in athletes who have not fully acclimatised to the environment and become dehydrated and salt depleted. Most cold-related sports injuries are seen in submaximal endurance sports such as marathon running or wilderness sports such as mountaineering and skiing. Cold climates reduce performance as the body must use energy stores for thermogenesis. Cold-induced injuries include chilblains, trench foot, frostbite and hypothermia. Pre-existing conditions, such as asthma, Raynaud's phenomenon and cold urticaria, can also be triggered by the cold. High altitude ranges from 1500 to 3500 m above sea level. Above 1500 m, the maximum oxygen uptake by the body reduces by 10% for every 1000 m. This results in reduced performance at endurance events. The opposite is true for performance at short anaerobic events, due to lower air resistance. Illnesses associated with high altitude include acute mountain sickness, pulmonary oedema, cerebral oedema and retinal haemorrhage.
HISTORY TAKING A significant part of the patient's initial consultation is likely to involve history taking. It is important to cover all relevant areas, otherwise vital clues may be missed, resulting in misdiag-
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nosis or inappropriate treatment planning. The consultation will start with noting the patient's personal details. In addition to the patient's name, address, date of birth, GP, information on other health care practitioners treating the athlete should also be recorded. Recording the contact details of the athlete's coach(es) is useful, as communication with them may assist the practitioner in identifying risk factors and ensuring the athlete adheres to any treatment plan. The following areas should be covered to achieve an accurate history: • • • • •
medical history social history drug history sport history injury history.
Medical history Taking an accurate medical history is essential in determining an athlete's suitability to perform a sport. As already discussed, poor physical fitness or systemic disease may predispose an athlete to injury. Diseases of the cardiovascular, respiratory, neurological, endocrine, gastrointestinal and genitourinary systems can affect performance and predispose injury. If medical conditions are identified, it is important to gain information about the onset, the type of symptoms experienced, the treating physician and the type of treatment. This information will help the practitioner to determine whether it is necessary to recommend participation in a different sporting activity or participation at a reduced level. The history of any surgical procedures should also be recorded. Surgical procedures due to systemic disease or previous injury may have direct relevance to the assessment of the current injury. Information related to all surgical procedures is important as it provides an indication of the overall health status of the athlete and the athlete's healing capacity. Also, any recent operations that may have resulted in a reduced training programme and fitness level, which may have
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contributed to the current sports injury, need to be noted. Both the patient and practitioner often overlook the role of nutrition in sports performance and injury. The practitioner should be aware of the nutritional requirements of athletic performance. Energy for exercise comes from carbohydrates, fats and, to a lesser extent, proteins. Muscle hypertrophy and skeletal development is reliant on proteins, vitamins and minerals. Homeostasis is dependent upon water, fibre and minerals. A healthy diet will incorporate the right balance of these foodstuffs. Athletes will often manipulate this balance in order to enhance performance: e.g. carbohydrate loading prior to endurance events, protein supplements to increase muscle mass and anaerobic power. Manipulation of foodstuffs may not be detrimental as long as it does not increase one source at the expense of reducing another. However, if the practitioner is in doubt and suspects the athlete's diet is contributing to the injury then referral to a dietitian or sports nutritionist is warranted. Other indications for referral may include rapid changes in body weight, vitamin deficiencies and BMIs below 18 or above 27. Accurate assessment of physical fitness is difficult without resort to specific exercise physiology tests. These tests are used to measure an athlete's ability to exercise aerobically or anaerobically. An impression of athletes' fitness can be gained from questioning them about their exercise programme, athletic performance, speed of recovery from exercise and injury history. Rapid increases in exercise intensity may not be associated with increases in physical fitness. Exercise at too Iowan intensity will also not produce improvements in fitness. As a general rule aerobic exercise must be performed at a level equivalent to 70-80% of the maximum heart rate. Exercising below this level will not produce significant improvements in fitness and exercise above this level may overstrain the cardiovascular system. A slow recovery from exercise may either be due to poor physical fitness or exercising at too high an intensity. Signs of a slow recovery may include laboured breathing post-exercise, severe fatigue or delayed-onset muscle soreness.
Social history The social history of the athlete will involve questioning them regarding their occupation, dietary and alcohol habits and whether they smoke. High alcohol consumption, smoking and a poorly balanced diet may all predispose the athlete to injury due to their effect on physical fitness. A patient's occupation is often overlooked but may be a significant factor in both the aetiology of the injury and its management. It may be difficult for an athlete to truly rest an injured structure if their occupation involves heavy manual work or standing for prolonged periods. The social network of family and friends may be a cause of stress to the athlete. If these stresses become significant they may contribute to the development of injury. Questioning the athlete on these issues may be necessary if the practitioner suspects psychological stress as an aetiological factor in the injury.
Drug history A thorough pharmacological history should include any current prescription only or overthe-counter medicines, previous medication and drug allergies. Current or past medication may indicate pathology not identified in the medical history. Drug allergies are obviously important, as they may contraindicate certain treatment options. Over-the-counter medicines may include nutritional supplements, homeopathic remedies, topical agents or pain medication. Pain medication is of particular importance, as it will mask some of the symptoms of the injury. This can result in the athlete and practitioner underestimating the severity of the injury, in addition to the potential long-term complications of such medication. The use of pharmacological aids to enhance sporting performance is now more commonplace. Such practices are not confined to the elite level. The practitioner should be aware of the potential risks associated with pharmacological abuse, particularly their role in injury development. This is mainly confined to anabolic steroids, which can significantly increase muscle
ASSESSMENT OF THE SPORTS PATIENT
mass, muscle strength and the psychological drive to exercise. These drugs may cause injury due to the increased forces placed through the musculoskeletal system from the greater exercise intensity. There is also some evidence to suggest that continual long-term use causes weakening of collagen structures, resulting in injury to tendon, ligament and muscle. Other more serious long-term effects can include cardiomyopathy, liver damage and testicular atrophy. Abuse at the elite level is further complicated by athletes using masking agents, which may themselves be detrimental to health. Evidence on the effects of other ergogenic aids such as protein, vitamin and mineral supplements, creatine, caffeine, blood doping and human growth hormone is currently lacking. Although these aids are commonly used, their potential benefit to athletic performance has not been clearly proven.
Sport history It is important to gain as much detail about the athlete's sporting history as possible. This should include the following:
• • • • •
type or types of sport frequency (number of times/week) duration intensity level.
The main sport the athlete participates in is of obvious importance but the practitioner should also focus on secondary sporting activities the athlete may undertake. These activities may be for interest or fitness but they can play a significant part in the development of an injury and should not be overlooked. Other factors to note would include the sports surface, footwear, limb dominance and sporting position. The frequency, duration and intensity of sporting activity will help the practitioner determine if the athlete is over- or under-training: both can lead to injury. Over-training can cause overuse injury, as there is insufficient time for tissue replenishment and regeneration. Under-training can cause injury due to inadequate levels of fitness or strength. As a general rule, to improve
389
cardiovascular fitness it is recommended to exercise three times a week for a minimum of 20 min each time at an intensity of 70-80% maximum heart rate. The duration of activity is important: too short an exercise period will not produce the desired physiological improvement in fitness, and too long a period will cause fatigue and possible injury. Duration should also include how long the athlete has been participating in that particular sport, as this will impact on his fitness and skill level. When questioning the athlete on his sporting activity, it is important to determine at what frequency, duration and intensity he was exercising at when the injury occurred. The practitioner should pay particular attention to recent changes to the training schedule (Case history 15.4). The level at which the athlete undertakes his sport is also important. This will help the practitioner determine the athlete's motivation to play
Case history 15.4 A 23-year-old semi-professional soccer player returned for treatment complaining of bilateral shin pain. Eighteen months previously he had been successfully treated for patellofemoral syndrome after being prescribed an exercise programme and orthoses for his football boots and AstroTurf training shoes. His shin pain had been present for 6 weeks and was gradually deteriorating. It was initially suspected that the shin pain was due to the orthoses becoming worn and less effective. Additional support was therefore added to the orthoses and the athlete was reviewed 2 weeks later. The pain was still present and it was at this stage that the athlete revealed that his training schedule had changed slightly. In addition to his normal soccer training, which consisted of 5 hours' practice and one game per week, he had started to attend a high-impact aerobics class. This was in a school hall with a nonsprung hardwood floor. For the gO-minute classes he wore an old pair of running shoes in which his orthoses did not fit. He was advised to discontinue the aerobics class and the shin pain resolved within 10 days. Highimpact aerobics on hard surfaces is associated with significant ground reaction forces and this had caused him to develop medial tibial stress syndrome. The lack of orthotic control and the poor shock absorption of his old running shoes had probably exacerbated the situation.
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'SPECIFIC CLIENT GROUPS
sport and may also guide the treatment plan. Elite or professional athletes may find it harder to rest or modify their activity than novice athletes. Convincing a professional athlete to take time out from their sport is often very difficult and should involve collaboration with other members of the sports medicine team or coaching staff. These athletes are often more demanding of the practitioner and can present a management challenge. When assessing an athlete's current participation level it is important to determine his athletic goals. Athletes may strive to achieve certain goals or reach a specific level of performance, such as running a distance in a given time or becoming a regular first team player for a sports club. Although these goals may be achievable the athlete will often have unrealistic expectations of the time it will take to reach that level of skill or fitness. Part of the assessment of the athlete and his injury may involve the practitioner giving advice on whether the athlete's goals are achievable in the short term.
Injury history As much information as possible should be gained about both previous lower limb injuries and the current injury. Previous injuries are important as they can make the athlete more susceptible to injury and they may also cause structural or functional compensations. Information on this area can be gained easily by asking questions such as: • Have you broken any bones within the lower limb? • Have you ruptured or torn any ligaments or tendons in the lower limb? • Is there a history of prolonged or intermittent swelling of any joints in the lower limb? • Have you had any injuries, which have resulted in missing more than 2 weeks from sport? With acute injuries there is often a history of a single traumatic event. The athlete may be able to describe how the injury occurred, making it easier for the practitioner to determine the
mechanism or pattern of injury. This information can enable the practitioner to identify the injured structure and the likely level of force that caused the injury. Diagnosis of both the injured structure and the injury severity is therefore easier. Identifying the injury mechanism in chronic or overuse injuries is harder as these injuries are usually associated with multiple minor traumatic events and the injury may have led to functional compensation. The location, duration and the type of pain can all assist the diagnosis of the injury. The location of pain may be diffuse and generalised or focal and specific to a single structure. This characteristic is important, as both generalised and focal pain can be typical of specific conditions. As an example, consider patellofemoral syndrome and patella tendonitis, which are both causes of anterior knee pain. Patella tendonitis will cause pain within the tendon or its sheath and is focal in nature. Patellofemoral syndrome is characterised by pain medial, posterior or lateral to the patella and is generalised in nature. This is sometimes referred to as the 'grab' sign, as the patient will grab the whole of the front of the knee when asked to locate the area of pain. The duration of pain will inform the practitioner both of how long the injury has been present and its severity. As a general rule, the longer the injury has been present the longer the recovery period will be from the initiation of treatment. This is usually because the injury has become more severe. Consider pathology of tendons as an example. Long-standing tendonitis can be associated with the formation of adhesions, scar tissue and mucinous degeneration of the tendon itself. This is referred to as tendonosis and will require more intensive and prolonged treatment that may take many weeks or months to resolve. Injuries which are intermittent in nature may be less severe or specifically associated with a sporting activity. Descriptions of the type of pain experienced are somewhat subjective. However, certain pain descriptions are characteristic of trauma to specific anatomical structures. Neurogenic symptoms usually involve paraesthesia, numbness or
ASSESSMENT OF THE SPORTS PATIENT
a burning sensation. A dull or intense aching sensation usually represents an injury to deep structures, especially muscle or bone. Sharp or throbbing pain may represent trauma to articular structures. The severity of the pain is especially subjective, as patients have differing tolerance and pain coping strategies. It is therefore best to assess the pain severity in conjunction with all other injury factors. Other factors to note about the injury are previous conservative treatment and what exacerbates or improves the injury. The majority of sports patients have usually been treated by another health care practitioner or attempted self-treatment prior to attending the podiatrist. This information may be particularly useful in determining injury severity and appropriate treatment planning. Accurate information on treatment by other health care workers may require communication between practitioners, which can also assist in making an accurate diagnosis through case discussion. Factors which exacerbate injury are usually sportrelated and may include any of the intrinsic and extrinsic risk factors discussed earlier. Factors outside of the athlete's sport may also contribute, such as occupation, social activities and non-athletic footwear. Many injuries have such characteristic histories that the injury diagnosis requires only minimal examination. A common example of this is exercise-induced leg pain, traditionally known as shin splints. The characteristics of the common causes of exercise-induced leg pain are shown in Table 15.3. The relationship of the pain to exercise is very diagnostic, as each condition significantly varies. In chronic compartment syndrome the
Table 15.3
391
pain is induced by exercise and the athlete must stop or reduce their exercise intensity. Upon cessation of exercise the pain goes completely within minutes. In medial tibial stress syndrome pain is rarely present during exercise but occurs within hours following exercise and may last up to 2 days post-exercise. The pain from stress fractures is exacerbated by exercise and usually becomes constant in nature unless the athlete completely rests.
EXAMINING THE INJURED STRUCTURE Following a thorough injury history, the practitioner may have formulated a provisional list of differential diagnoses. This process is assisted by observation of the injured site and adjacent structures. Marked swelling, bruising and erythema often accompany acute injuries, whereas in chronic injuries these signs may be minimal or absent. Observation of adjacent structures is useful to gauge the level of any swelling or to determine deformity. Unilateral injuries should always be visually compared with the asymptomatic side. This will require having the athlete prone when the injury is on the posterior surface such as with Achilles tendon injuries. From the history and visual inspection the practitioner should be able to identify the potential injured anatomical structures. The next phase of the examination will be to individually isolate the structures and then apply stress to them in a controlled manner. The application of stress should be gradually increased until the athlete's symptoms are reproduced. Stress is initially applied by gentle and then firm
Characteristics of the common causes of exercise-induced leg pain
Pain characteristic
Medial tibial stress syndrome
Tibial stress fracture
Chronic compartment syndrome
Location
Tenoperiosteal junction
Bone
Muscle compartment
Nature
Diffuse
Focal
Diffuse
Description
Dull ache
Intense ache
Tightness, fullness, cramping
Relationship to exercise
Post-exercise, lasts <2 days
Constant, made worse by exercise
Induced by exercise, immediate relief with rest
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SPECIFIC CLIENT GROUPS
---,--------
palpation. The level of pressure required when palpating the area is determined by the tissue type and depth. Deep dense structures such as tendon or bone will require firmer pressure than more superficial structures or those that are less dense such as muscle or ligament. Movement of the injured structure should also be performed. This should initially be passive, with the practitioner directing the movement. If this is pain-free, the patient should be directed to move the structure actively with no resistance applied. In the majority of sports injuries both of these types of movements are unlikely to cause pain. The next step is to apply active resistance to the movement. This should first be performed with concentric contraction and then eccentric if the first movement did not induce symptoms. These contractions should be held for between 10 and 20 seconds. In the majority of cases resisted eccentric or concentric contraction will induce symptoms. The method of achieving the greatest stress is to have the athlete perform dynamic or functional exercises: examples of these movements are double or single knee squats to stress the patellofemoral joint and the single leg tiptoe test
Table 15.4
to stress the posterior tibial tendon or have the athlete go up and down on their forefoot with the heel over the edge of a stair to stress the Achilles tendon. A dynamic functional assessment should be included in any orthopaedic examination. For the athlete with a sports injury this may require the practitioner to observe the athlete's sporting technique in addition to normal static stance and gait analysis. Many of these sporting movements can be performed in a relatively small space or on a treadmill. Occasionally, a practitioner may have to go and observe the athlete in his natural sporting environment.
Specialist investigations As with any investigation, specialist tests should only be performed if the results may change the treatment plan. Specialist investigations in sports medicine are primarily used to assist in diagnosing and grading the severity of an injury. A summary of the various tests and the common sports injuries they may be used to diagnose is given in Table 15.4. X-ray remains the mainstay diagnostic test for osseous pathology and MRI or ultrasound for soft tissue pathology. A number of
Specialist investigations used in sports injury assessment
Investigation
Main uses
Common sports injuries diagnosed
X-ray
Articular and osseous pathology
Fractures, ligament ruptures or laxity, osteochondral defects, osteochondritides
Computed tomography (CT)
Osseous, especially cortical pathology
Stress fractures, cartilage tears, osteochondral defects
Magnetic resonance imaging (MRI)
Tendon, ligament, muscle, cartilage, bone marrow pathology
Tendonopathies, ligament injuries, muscle tears, cartilage tears, stress fractures, osteochondral defects
Nuclear bone scanning
Abnormal bone activity
Stress fractures, medial tibial stress syndrome, osteochondritides
Ultrasound
Tendon, ligament, muscle, fascial pathologies
Tendonopathies, plantar fasciitis
Intracompartmental pressure studies
Muscle/fascial pathology
Compartment syndromes
Nerve conduction studies
Nerve pathology
Exercise-related nerve entrapments
Arteriography/venography
Arterial and venous pathology
Effort-induced deep vein thrombosis, arterial entrapment syndromes
ASSESSMENT OF THE SPORTS PATIENT
393
----------------------------------------------------, - - - ,
conditions such as stress fractures, osteochondral defects and the osteochondritides may be diagnosed by several different modalities. In these cases the choice of modality will depend upon the injury history, and the cost and access of the modalities.
Injury grading systems As with many pathologies, sports Injuries are often graded by their severity. These classification systems are primarily used to direct treatment protocols. As an example, grade one ankle sprains are treated differently from grade three sprains. Grading systems are also useful when communicating with other health care practitioners in the sports medicine team about the patient. They can also be used to help explain the nature of the pathology to the athlete or coach. Grading systems may describe an injury to a tissue type such as ligament, bone or tendon, or be specific to a certain injury such as posterior tibial tendon dysfunction, osteochondral talar defects or Achilles tendon injuries. The grading systems for muscle and ligament injuries and tendonitis are given in Table 15.5.
SUMMARY The practitioner should involve the patient as much as possible in the assessment process.
Table 15.5
Athletes are often well educated in their area of sport and this can greatly assist the practitioner. Likewise, the practitioner must educate the patient, as this will play a crucial role in the success of the treatment. The majority of sports injury treatments require the athlete to follow specific advice or instructions. Compliance is intricately linked to understanding so the practitioner must educate the athlete about the injury and the purpose of any treatment. A structured holistic approach is essential in the assessment of the sports patient. The practitioner should develop a logical assessment scheme that meets the patient's and his own needs in whatever assessment environment they are working in. The successful treatment of lower limb sports injuries requires the practitioner to assimilate knowledge from areas as diverse as sports psychology, exercise physiology and sports biomechanics. This knowledge will assist in the diagnosis of the injury risk factors. Identification of these intrinsic and extrinsic risk factors should form the main focus of the assessment. Diagnosis of the injury itself requires detailed knowledge of the regional anatomy and common sports injuries that affect the lower limb. Athletes with chronic overuse injuries can be very difficult to treat. The assessment principles outlined in this chapter are designed to help the practitioner meet these management challenges.
Grading systems for ligament injuries and tendonitis
Grade
Ligament injuries
Tendonitis
Muscle tears
One
Stretching of the ligament without macroscopic tears
Pain after exercise
Minimal tear with no loss of strength
Two
Partial macroscopic tear
Pain pre- and post-exercise, pain reduced during exercise
Macroscopic tear with loss of strength
Three
Complete rupture
Pain before, during and after exercise
Complete tear with no function
Four
Constant pain and volume of exercise reducing
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SPECIFIC CLIENT GROUPS
REFERENCES Almeida S A, Trone D W, Leone D M, Shaffer R A, Patheal S L, Long K 1999 Gender differences in musculoskeletal injury rates: a function of symptom reporting. Medicine and Science in Sport and Exercise 31(12): 1807-1812 Anderson B, Burke E R 1994 Scientific, medical, and practical aspects of stretching. In: Delee J C, Drez D (eds) Orthopaedic sports medicine, Vol 1. W B Saunders, Philadelphia Beck B 1998 Tibial stress injuries: an aetiological review for the purposes of guiding management. Sports Medicine 26(4): 265-279 Bennell K L, Malcolm S A, Thomas S A et al1996 Risk factors for stress fractures in track and field athletes: a 12 month prospective study. American Journal of Sports Medicine 24: 810-818 Bowers K D, Martin R B 1976 Turf toe: a shoe surface related football injury. Medicine and Science of Sports 8: 81-83 Bradshaw C 2000 Exercise related lower leg pain: vascular. Medicine and Science in Sports and Exercise S34-36 Brukner P, Bennell K, Matheson G 1999 Stress fractures. Blackwell Science, Oxford Bruns W, Maffulli N 2000 Lower limb injuries in children in sports clinics. Sports Medicine 19: 637-662 Cantu R, Micheli L (eds) 1991 American College of Sports Medicine guidelines for the team physician. Lea & Febiger, Philadelphia Cavanagh P R, Kram R 1990 Stride length in distance running. Medicine and Science in Sports and Exercise 21(4): 467-479 Colville M R 1998 Surgical treatment of the unstable ankle. Journal of the American Academy of Orthopaedic Surgeons 6: 368-377 Cook S D, Kester M A, Brunet M E 1985 Shock absorbing characteristics of running shoes. American Journal of Sports Medicine 13: 248-253 Dalton S E 1992 Overuse injuries in adolescent athletes. Sports Medicine 13(1): 58-70 Friberg 0 1982 Leg length asymmetry in stress fractures: a clinical and radiological study. Journal of Sports Medicine 22: 485-488 Gardner L I, Dziados J E, Jones B H et al 1988 Prevention of lower extremity stress fractures: a controlled trial of a shock absorbent insole. American Journal of Public Health 78: 1563-1567 Gerrard D F 1993 Overuse injury and growing bones: the young athlete at risk. British Journal of Sports Medicine 27(1): 14-18 Griffin L Y 1994 The female athlete. In: Delee J C, Drez D (eds) Orthopaedic sports medicine Vol 1. W B Saunders, Philadelphia Herring K 1993 Injury prediction among runners. Preliminary report on limb dominance. Journal of American Podiatric Medical Association 83(9): 523-528 Hreljac A, Marshall R N, Hume P A 2000 Evaluation of lower extremity overuse injury potential in runners. Medicine and Science in Sports and Exercise 32: 1635-1641 James S 1, Bates B T, Osternig L R 1978 Injuries to runners. American Journal of Sports Medicine 6: 40-50
Jones B H, Vogel J A, Manikowski R et al1988 Incidence of and risk factors for injury and illness among male and female army basic trainees. US Army Research Institute of Environmental Medicine technical report T19-88 Knapik J J, Jones B H, Bauman C L, McArthur-Harris J 1992 Strength, flexibility and athletic injuries. Sports Medicine 14(5): 277-288 McKenzie D C, Clement D B, Taunton J E 1985 Running shoes, orthotics and injuries. Sports Medicine 2: 324-327 Marks R M 1999 Achilles' tendonopathy. Foot and Ankle Clinics 4(4): 789-809 Myburgh K H, Grobler N, Noakes T D 1988 Factors associated with shin soreness in athletes. Physician and Sports Medicine 16: 129-134 Neely F 1998 Intrinsic risk factors for exercise-related lower limb injuries. Sports Medicine 26(4): 253-263 Nicholl J P, Coleman B A, Williams B T 1991 Pilot study of the epidemiology of sports injuries and exercise related morbidity. British Journal of Sports Medicine 25(1): 61-66 Nigg B M, Yeadon M R 1987 Biomechanical aspects of playing surfaces. Journal of Sports Science 5: 117-145 Pope R P, Herbert R D, Kirwan J D 1998 Effects of flexibility and stretching on injury risk in army recruits. Australian Journal of Physiotherapy 44: 165-172 Pope R P, Herbert R D, Kirwan J D, Graham J B 2000 A randomized trial of pre-exercise stretching for the prevention of lower limb injury. Medicine and Science in Sport and Exercise 32(2): 271-277 Protzman R, Griffis C 1977 Stress fractures in men and women undergoing military training. American Journal of Bone and Joint Surgery 59(6): 825 Richie D, Devries H, Endo C 1993 Shin muscle activity and sports surfaces: an electromyographic study. Journal of American Podiatric Medical Association 83(4): 181-189 Ross J, Woodward A 1994 Risk factors for injury during basic military training: is there a social element in injury pathogenesis. Journal of Occupational Medicine 36: 1120-1126 Rossiter N, Galbraith K 1996 The incidence of hypermobility in a military population (abstract). Meeting of the Combined Services Orthopaedic Society, Aldershot, UK, 165 Strocchi R, DePasquale V, Guizzardi S et al1991 Human Achilles tendon: morphological and morphometric variations as a function of age. Foot and Ankle 12: 100-104 Tomten S E, Falch J A, Birkeland K I et al1998 Bone mineral densities and menstrual irregularities: a comparative study on cortical and trabecular bone structures in runners with alleged normal eating behavior. International Journal of Sports Medicine 19: 92-97 Walsh W M 1994 Patellofemoral joint. In: Delee J C, Drez 0 (eds) Orthopaedic sports medicine Vol 2. W B Saunders, Philadelphia Witvrouw E, Lysons R, Bellemans J, Combier D, Vander Straeton G 2000 Intrinsic risk factors for the development of anterior knee pain in an athletic population. American Journal of Sports Medicine 28: 480-489
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FURTHER READING Brukner P, Khan K 1993 Clinical sports medicine. McGrawHill, Sydney Brukner P, Bennell K, Matheson G 1999 Stress fractures. Blackwell Science, Victoria Delee J C, Drez D (eds) 1994 Orthopaedic sports medicine, Vols 1-3. W B Saunders, Philadelphia
Hartley A 1995 Practical joint assessment: lower quadrant. 2nd edn, Mosby, St Louis Nicholas J A, Hershman E B 1995 The lower extremity and spine in sports medicine. Mosby, St Louis Subotnick S (ed) 1999 Sports medicine of the lower extremity, Vol 2. Churchill Livingstone, New York
CHAPTER CONTENTS Introduction 397 Factors to consider when assessing 397 Examination of the patient with foot pain 398 Measurement and assessment of pain 398 Tools of assessment - how do we score pain? 399 CAUSES OF PAIN IN THE FOOT
403
Articular and bone conditions 403 Osteoarthritis (OA) 403 Footballer's ankle 404 Osteochondritis dissecans(ankls/talocrural joint) 405 Hallux rigidus 406 Accessory ossicles 407 Stress fractures 408 Subungual exostosis 408 Tarsal coalition 409 Metatarsalgia 410 Sesamoiditis 411 Tumours 411 Soft tissue, tendons and ligaments Tendonitis 412 Subluxing peroneal tendons 413 Chronic ankle sprain 413 Sinus tarsi syndrome 414 Compartment syndrome 414
412
Nerves 415 Tarsal tunnel syndrome 415 Other entrapments 416 Peripheral neuropathy 417 Morton's metatarsalgia (neuroma) 417 Skin and subcutaneous tissues 418 Retrocalcaneal bursitis 418 Heel pad syndrome 419 Plantar fasclitis 419 Soft tissue masses or tumours 420 General 420 Crystal arthritis 420 Hereditary and motor sensory neuropathy 421 Infection 422 Reflex sympathetic dystrophy (RSD) 423 Referred pain 424 Summary
424
The painful foot W. Turner R. Ashford*
INTRODUCTION Before embarking on a description of conditions that affect the foot and can cause pain it is important to have a working knowledge of the concept of pain: how it manifests, how it is measured and assessed, other indicators of pain and current thought regarding the treatment of pain. Why do we need to measure pain? Pain in the foot has plagued mankind for as long as humans have existed. As practitioners it is only relatively recently that the importance of monitoring foot pain has been recognised. Previously we may have asked the patient 'how' their pain was progressing between treatments; however, rarely did we chart this most important aspect of patient management. Needless to say, as practitioners we need to chart and monitor all aspects of treatment intervention so as to provide the information to compare single patients as well as groups of patients. This, in turn, gives the practitioner the facility to monitor the progress of individual patients as well as objective data to validate new treatment regimens.
Factors to consider when assessing It is essential to recognise that pain is subjective. Only the person experiencing the pain knows how it feels, its intensity, location and the restriction it places on their lives. 'Pain is whatever the experiencing person says it is, existing whenever "The editors wish to acknowledge the work of David Tollafield. This chapter is based on his work in the previous edition.
397
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SPECIFIC CLIENT GROUPS
the experiencing person says it does' (McCaffery & Beeke 1989). A simple illustration of a misconception of a painful foot is when a healthy patient seeks treatment for what looks like the tiniest corn on the fifth toe. The patient complains of severe pain, finds it difficult to walk and complains of throbbing when the bed clothes are pressing on it. Compare this to the frail patient who presents with heavy callosities over the first and fifth metatarsals and with deep-seated corns located beneath. The patient complains of moderate pain from the lesions. Practitioners may intuitively select the frail patient as the one suffering the most pain. Is this assessment justified? With any assessment it is important to remember that pain is relative; it is a very individual thing and it is important to distinguish between bias and inaccuracy. Studies have shown that practitioners find it difficult to assess pain accurately and to assess the degree of pain experienced by the patient (Sutherland et al 1988). Such inaccuracies can in some way be overcome by the use of validated and reliable clinical tools dedicated to the assessment of pain. However, clinical tools must be seen as an adjunct to patient assessment of pain and not a panacea. It is suggested that a clinical picture is built up before undertaking charting of pain levels. As discussed in Chapter 3, it is important to consider the following: • • • • •
What eases or aggravates the pain? At what time of the day is it worse? Is the pain constant or intermittent? What type of medication is the patient taking? What is the previous medical history and history of injury?
Pointers concerning general health include: • Does the patient look well? • Is the patient well nourished (obese or thin and wasted)? • Colour (pale and anaemic, jaundiced)? • Look at the hands, are they misshapened (rheumatoid arthritis)? The physical examination may reveal findings that raise concerns. For example, a manual worker who has thick calluses on his hands, yet says he cannot work because of the pain in his foot, may be less than fully honest. Examination of the foot begins with watching the patient walk (Ch. 8). An antalgic limp, where the patient will spend only a short period of time on the painful foot, is a clear positive sign. The limp may be linked with other problems associated with proximal joints or the back; these should be excluded. Look at shoe wear on the sole; this may indicate an abnormal gait pattern. Are the toes severely clawed, suggesting a neurological problem? It is important to note any callosities, both dorsally and on the sole, as these indicate areas of high pressure and friction. Similarly, one must remember all the structures running under any area of tenderness. The sources of pain are numerous (Table 16.1) and can be subdivided for convenience into problems affecting different tissues, generalised disorders and referred pain. The table provides an overview of typical problems associated with the painful foot. In many cases the origins are not clear and assessment and investigations are necessary to isolate the cause.
Measurement and assessment of pain Examination of the patient with foot pain Your first observation should be to look at the patient, not the foot. It is useful to highlight those traits that have been discussed under medical history (Ch. 5) as the source of pain may be explained by general disease processes. Assess the patient's attitude. This may reveal psychological variations from normal and may influence the outcome in terms of treatment.
Measurement and assessment of pain is an integral part of the assessment and treatment planning process. It gives the practitioner information regarding the patient's readiness for treatment, the focus of the appropriate intervention and a quantifiable measure of the disruptiveness of the problem. With pain being such a personal experience, many measures of pain are based on patient selfreports. More objective measurements of pain
THE PAINFUL FOOT
Table 16.1 Sources of pain classified under tissue types. The table provides an overview of typical problems associated with the painful foot. In many cases the origins are not clear and assessment and investigations are necessary to isolate the cause
Condition
Aetiology
Articular and bone
Osteoarthritis
General degeneration
Footballer's ankle
Chronic injury
Table 16.1
399
(Cont'd)
Condition
Aetiology
Skin and subcutaneous
Retrocalcaneal bursitis
Repetitive injury/mechanical rheumatoid
Heel pad
Obesity/occupational referred from back
Plantar fasciitis
Repetitive injury, biomechanical
Osteochondritis dissecans
Chronic injury
Onychocryptosis
Iatrogenic/congenital
Hallux rigidus
General degeneration
Plantar warts
Infective
Toe deformities
Congenital and acquired
Callosity/corns
Accessory ossicles
Congenital/injury
Biomechanical/deformity/ endocrine/footwear design
Stress fractures
Repetitive injury
Ulcers
Subungual exostosis
Repetitive injury
Vascular/infective/trau matic/ dermatological/neoplastic
Exostoses
Injury/dislocation/ biomechanical
Tarsal coalition
Congenital
Metatarsalgia
General degeneration/referred/ multifactorial/rheumatoid
Sesamoiditis
Repetitive injury/degenerative
Bony or cartilaginous tumours
Neoplastic metastasis, primary or secondary
Periosteal/joint
Infective/neoplastic metabolic/ autoimmune reactive
Soft tissue
Tendonitis Subluxing peroneal } tendons Chronic ankle sprain Compartment syndrome
Most of these are associated with injury
Sinus tarsi
Degenerative/trauma or rheumatoid manifestation
Nodules
Dermatological/rheumatoid Ganglia/cysts
Nerves
Tarsal tunnel
Degenerative/biomechanical
Peripheral neuropathies
Metabolic/endocrine/proximal entrapment or trauma
Interdigital neuromata
Repetitive injury and (Morton's) degenerative
Hereditary and motor sensory neuropathies (HMSN)
Congenital with hereditary predisposition
Radicular pain
Lumbar referred pain
Vascular
Peripheral vascular disease
Socioenvironmental/endocrine and metabolic
Acute embolism
Secondary to other factors, e.g. atherosclerosis
Buerger's disease
Ethnic and social factors predispose to manifestation
tend to rely on a single dimension - namely, pain intensity. These measures tend to focus on three aspects of pain: physical, functional and behavioural. Physical pain can be measured in terms of intensity, location or physical symptoms. Functional measurements of pain rely on assessing such things as walking distance or activity levels, whereas behavioural aspects are more difficult to assess and include assessing patients' behaviour towards protecting the affected painful area or assessing the abnormal gait which may have developed because of the pain. Other measurements of pain include multidimensional analyses. Such tools attempt to assess pain in a number of different dimensions. They tend to use multiple visual analogue or number ranking scales. Listed below is a selection of single and multidimensional pain assessment tools.
Tools of assessment - How do we score pain? V~ualana0guesca~s
Visual analogue scales (VAS) are used to measure pain, treatment satisfaction and other related treatment interventions. The main advantages of this measure are that it is quick, easy to administer, cheap and easily attached to any patient record card. The disadvantages are that these scales only measure one dimension of pain, give
400
SPECIFIC CLIENT GROUPS
a single reading and misinterpretation of the scoring mechanism, particularly among the elderly, who frequently mark the wrong place or misinterpret the scoring continuum. The VAS consists of a 10 cm line that ranges from 'no pain' to 'worst possible pain'. Patients are asked to mark on the line their reported level of pain (Fig. 16.1). Another form of VAS can be presented as a pain thermometer (Fig. 16.2). Verbal scales
On similar lines, the simple verbal scales (VS) categorise pain into discrete groups such as mild pain, moderate pain, severe pain or worst pain. Again, these can be presented to the patient in a linear fashion (Fig. 16.3). Patients are then instructed to circle the most appropriate descriptor of pain. One major advantage, like all scale measurements of this nature, is that they are cheap to administer; another major advantage is that each
No pain
Figure 16.1
Worst possible pain A visual analogue scale 10 em in length. Worst possible pain
descriptor is a discrete item, and therefore patients are only allowed to choose one. The main disadvantage revolves around the type of data that can be extrapolated from measurements of this kind. One way round this problem is to give each of the descriptors a number, so that the data collected can then be analysed as nominal data (see Ch. 4). Questionnaires
A multidimensional pain tool, the McGill Pain Questionnaire (MPQ) (Melzack 1975) was devised in Canada and contains sets of words that are used to quantify pain levels. The full questionnaire consists of 78 adjectives arranged into 20 groups. The groups are set out to reflect similar pain qualities. The advantage of such a comprehensive verbal descriptive scale is that it offers patients the opportunity to describe their pain on a number of dimensions; for example, it endorses both emotional and sensory descriptors. The MPQ is a comprehensive reliable multidimensional pain assessment tool. It has been extensively tested in the clinical arena for both reliability and validity and consistently scores well in these domains. The major disadvantage, especially in a busy clinic, is the length of time the questionnaire takes to complete. It is therefore not ideal for continual use in monitoring chronic pain, and a short version of the MPQ has been developed which is easy to administer and can be repeated easily at short return dates. ~ .. ' . ' W
"npra.
No pain
Mild pain
I
I
Moderate pain
Severe pain
OR
No pain Mild pain
Moderate pain Severe pain Worst pain
No pain Figure 16.2 Another form of the visual analogue scale can be presented as a pain thermometer.
Figure 16.3
Examples of verbal scales.
l
Worst pain
THE PAINFUL FOOT
A similar and briefer pain scale is the 52-item West Haven-Yale multidimensional pain inventory (WHYMPI). This scale is specifically based on cognitive behavioural models of pain behaviour and is used mainly for chronic pain monitoring. It comprises three parts: the impact of pain on the patient's life, the patients' perception of the response of others to their communication of pain and suffering and their levels of participation in daily life. The major advantages compared with the long PMQ are that this tool is much quicker to administer and it gives a rounder picture of the patient's distress in relation to pain. Two further tools are worth noting: the Wisconsin brief pain inventory and the pain perception profile developed by Tursky and colleagues. Again, both are quicker to administer than the MPQ and have a number of diseasespecific advantages when assessing pain. Observational techniques
Although not particularly relevant to painful foot management, but included for completeness, a short description of this technique is outlined. As the name suggests this technique involves the practitioner recording observed patient pain levels. This might include time spent resting, medication used, sleep patterns and verbal! motor pain behaviour. These techniques are notoriously difficult and unreliable because precisely defined behaviours are required and staff are then required to score these subjective behaviours. These techniques are particularly useful in the assessment of patients with severe learning disabilities or communication problems. Physiological measures
Unfortunately, little use of physiological monitoring of pain has been reported in the clinical setting. Researchers have attempted to measure autonomic function or disease activity as analogues for the experience of pain. The results from these studies and similar work is equivocal and suggest that at present physiological measures of pain are unreliable and really should not be considered for monitoring purposes.
401
Related measurement tools
As well as measuring pain, many of the generic tools currently available also assess quality of life (QoL) issues. It is arguable that pain, particularly in relation to foot health (see below), cannot be seen in isolation. Other measurements of disease have to be considered when assessing and monitoring patients' health status. Therefore, coupled with pain measurement and assessment, another important dimension has entered the patient assessment arena. It has become increasingly clear that one cannot separate a patient's pain from their current QoL. Quality of life, in this context, can be defined as 'the impact of disease and treatment on disability and daily living or a patientbased focus on the impact of a perceived health state on the ability to lead a fulfilling life' (Price 1996). In this context, tools such as the sickness impact profile (SIP) have been introduced. Not designed specifically for the measurement of pain, this tool assesses the effect of certain treatment interventions in relation to quality of life. It is designed to look at aspects of activities of daily life affected by chronic low-level sickness. Finally, other related tools have been devised, again not specifically to measure and assess pain but to quantify the extent of a patient's health status. Included in such tools are measures of dimensions such as mobility, physical activity, dependency and pain. A good example of such a generic measurement scale is the Arthritis Impact Measurement Scales (AIMS). As the name suggests, this tool was specifically designed to assess how a designated disease impacts on the ability of a patient to function in daily life. The short form-36 (SF-36) is also worth a mention in this context. This particular questionnaire was devised from the Rand health batteries (Stewart & Ware 1992). The SF-36 includes in its eight dimensions: physical function, social functioning, role limitations due to emotional problems, mental health, energyIvitality, pain and general health perceptions. Also included is a single item about perceptions of health changes over the past 12 months. There are many more examples of these health status tools: some are disease-specific and others are much more
402
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Instructions: The line next to each item represents the amount of pain you typically had in each situation. On the left is "No pain" and on the far right is "Worst pain imaginable." Place a mark on the line to indicate how bad your foot pain was in each of the following situations during the past week. If you were not involved in one or more of these situations mark them as NA. Questions: How severe was your foot pain: 1. At its worst? 2. Before you get up in the morning? 3. When you walked barefoot? 4. When you stood barefoot? 5. When you walked wearing shoes? 6. When you stood wearing shoes? 7. When you walked wearing orthotics? 8. When you stood wearing orthotics? 9. At the end of the day?
Figure 16.4
The Foot Function Index pain subscale.
generic. If such tools are to be considered the practitioner is well advised to check the reliability and validity of the selected measuring tools in the context of the condition they are proposing to monitor (Bowling 1995). Foot specific (pain) questionnaires
The pain tools described above are generic and not specific to the foot. They are useful and have been used in clinical settings and a selection of research studies. A foot-specific pain scale that is reliable and valid has yet to be developed. The development of the Foot Function Index (FFI) by Budiman-Mak et al (1991) marked the first attempt to measure foot dysfunction. The index is split into three discrete sections: foot pain (Fig. 16.4), disability and activity restriction. The pain section of FFI consists of nine questions that address the severity of the pain experienced during specific circumstances. A study by Saag et al (1996) demonstrated the reliability of this section (pain) of the FFI in relation to arthritic foot pain. Being easy to administer and foot-specific, the pain section of the FFI is well worth considering in the clinical arena.
Another foot-specific questionnaire worth considering for foot monitoring is the Foot Health Status Questionnaire (FHSQ) developed at Queensland University of Technology, Australia. This tool was developed to measure foot health related quality of life. Although not pain-specific, this tool includes pain as an indicator in one of the three subsections. In the section including pain there are a further three hypothesised domains of foot health: namely, foot function, footwear and general foot health (Table 16.2) (Bennett & Patterson 1998). Bennett et al (1998) demonstrated the validity of this tool in their study and concluded that a tool such as this could be used by researchers and practitioners to identify changes to foot health status as a result of different interventions (remember this is one of the key points when monitoring pain). It is short and easy to administer, particularly in the clinical setting; it can also be administered by a postal survey. One of the major disadvantages in relation to pain monitoring is that this tool incorporates pain as a dimension of foot health. As a consequence, pain per se cannot be analysed separately using this tool.
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403
• Inflammatory arthropathies such as rheumatoid
CAUSES OF PAIN IN THE FOOT ARTICULAR AND BONE CONDITIONS
•
Osteoarthritis (OA)
•
Degenerative arthritis may affect any of the joints of the foot and ankle. The joints most commonly affected are the ankle, subtalar, calcaneocuboid, talonavicular, first tarsometatarsal and first metatarsophalangeal joint (MTPJ). The first MTPJ will be considered separately under the heading of hallux rigidus.
•
Aetiology
This may be primary with no known cause but, while such arthritis is common in the hip and knee, it is rare in the ankle. Far more commonly OA is secondary to some insult to the joint and may follow major injury, such as a fracture extending into the joint, a dislocation or repeated minor trauma. Fractures of the neck of the talus may also lead to OA of the ankle. Other causes can include:
• Infection in the joint. Septic arthritis, unless diagnosed and treated early, will lead to lysis of cartilage and secondary OA. Table 16.2 Domain
•
arthritis (RA) and the seronegative arthritides, e.g. psoriatic arthritis, Reiter's disease and ankylosing spondylitis. Metabolic disorders such as gout and pseudogout. Systemic diseases such as diabetes mellitus, which can lead to Charcot foot or ankle; the ankle is affected in about 10% of Charcot foot cases. Proximal malalignmeni, e.g. following a malunited fractured tibia, has frequently been stated to lead to arthritis by imposing abnormal stresses on distal joints. While some authors have allowed up to 10° in the sagittal or frontal plane (Nicoll 1964), others have felt that even a few degrees of angulation may lead to significant problems (Johnson 1987). Merchant disputed this in a long-term followup study when he could find no correlation between the degree of malunion and the occurrence of OA (Merchant & Dietz 1989). Other miscellaneous conditions such as haemophilia or avascular necrosis (Freiberg's disease affecting second metatarsal head).
Presenting symptoms
Generally these will be pain and stiffness in the area of the affected joint. Symptoms may start as
The four basic domains of foot health as evaluated by the Foot Health Status Questionnaire (FHSQ) No. of items
Theoretical construct
Meaning of lowest score (0)
Meaning of highest score (100)
Foot pain
4
Evaluation of foot pain in terms of type of pain, severity and duration
Extreme and significant foot pain that is acute in nature
No pain or discomfort in any part of the foot
Foot function
4
Evaluation of feet in terms of impact on physical function
Severely limited in performing a broad range of physical activities because of feet: limited in walking, working and moving about
Can perform all desired physical activities: walking, working and climbing stairs
Footwear
3
Lifestyle issues related to footwear and feet
Extremely limited in access to suitable footwear
No problems with obtaining suitable footwear
General foot health
2
Self-perception of feet (individual's subjective assessment of body image related to feet)
Generally perceives feet to be in a poor state of health and identifies poor condition of feet
Perceives feet to be in an excellent state of health and condition
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SPECIFIC CLIENT GROUPS
aching after exercise and progress of pain after walking a distance. With time and progression of the arthritis the distance the patient can walk without pain gradually reduces. Pain may become constant and also present at night, disturbing sleep. How much pain the patient is experiencing is important to know but quantifying pain is difficult, because individual patients will have different tolerances to pain and different attitudes to the degree of their disability. While one can ask the patient to quantify their pain on a visual analogue scale of, say, 1-10, it is function which probably influences us most when it comes to determining treatment. While one must beware the stoic who pushes himself on regardless of the pain (and vice versa), how much a patient can do is often a good indicator of how severe the symptoms are. Stiffness may initially occur after the joint has been rested for a while, but with time the range of movement in the affected joint will decrease. Dorsiflexion is usually the first movement to be lost, and shoes with a slight heel raise may therefore be more comfortable. In severe OA the joint may completely lose movement and become virtually ankylosed. Patients may also complain of a limp, swelling or joint deformity. Signs
The joint may appear swollen or deformed or be held in an abnormal position. The joint may feel warm if the underlying cause is infection or an inflammatory arthropathy, but otherwise not. An effusion may be present in ankle OA but is not usually clinically detectable in OA of other foot joints. Osteophytes may be felt in superficial joints as hard bony swellings and represent new bone formation around the periphery of affected joints. Localised tenderness may also be found. The range of movement of the joint will be reduced, the degree depending on how advanced the arthritis is, and movement will be painful, more so at extremes. Often movement may feel 'dry', rather than smooth and easy. In advanced OA grating or crunching may be felt by the examiner as the joint is moved.
Investigations
Plain X-rays, generally standing anteroposterior (AP for ankle, DP (dorsiplantar) for foot) and lateral, are essential (Ch. 11). The cardinal signs of OA are reduced joint space, sclerosis, cysts and osteophytes (see Fig. 11.27). Standing films are helpful as they may demonstrate deformity under load and the true loss of joint space due to cartilage erosion. Special views may be helpful to show the subtalar joint; Anthonsen's view shows the medial and posterior subtalar facets. If infection is suspected then any open wounds can be swabbed. Aspiration of the joint to obtain bacteriology may be helpful. Results from blood tests will be normal and are unhelpful unless the OA is secondary to a systemic disease, infection or metabolic cause such as gout (Ch. 13). Further to the discussion on pain it should be noted that the degree of X-ray change does not always correlate in a linear fashion with the patient's symptoms or disability. It is always important to treat the patient and not the X-ray. Differential diagnosis
In early OA, when X-rays are normal, a presumptive diagnosis may be made solely on information from the history, symptoms and signs. Other periarticular causes should be considered however. In established OA, with X-ray changes, the differential diagnosis will usually lie in determining the underlying cause.
Footballer's ankle Aetiology
This condition was well described by McMurray in 1950 and occurs in soccer players as a result of repeated kicking of the ball with the foot held in equinus (McMurray 1950). In this position the anterior capsule largely takes the strain, as the extensor tendons are mechanically disadvantaged, and bony traction spurs develop. Presenting symptoms
These will be pain, often on kicking a stationary ball, but also on dorsiflexion of the ankle. The
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405
.... C~se history 16.1 Patient: 24-year-old professional footballer. Presenting symptoms: 1 year history of pain over dorsum of the right ankle. This had gradually increased and was painful especially when running. There was no history of instability. 3 months previously the patient had undergone removal of 'bony spur' by the club doctor, but symptoms had persisted and he was currently unable to play football. Signs: Some discomfort on full dorsiflexion but no discernible loss of movement. Investigations: Plain X-rays showed osteophytic lip to anterior margin of right tibia, with evidence of previous removal of talar spur. Diagnosis: Partially treated footballer's ankle. Operative findings: Arthroscopy showed synovitis of ankle and confirmed osteophytic anterior tibial margin. This was resected. Postoperatively the patient made a good recovery and returned to the first team. Figure 16.5 X-ray showing footballer's ankle with an anterior tibial spur - lateral view.
patient may complain of some restriction of dorsiflexion. Signs
Local tenderness over the neck of the talus and anterior tibial margin; pain on dorsiflexion of the ankle and perhaps some restriction of this movement.
Osteochondritis dissecans (ankle/talocrural joint) Aetiology
This is an interesting condition in which an osteochondral fragment becomes separated from the talar dome, usually posteromedially or midlaterally. It is now thought that all of the lateral and most of the medial lesions originate from trauma, probably associated with inversion injuries of the ankle (De Smet et aI1990).
Investigations
Plain X-rays will demonstrate a dorsal talar spur and also a spur on the anterior lip of the tibia. The spur on the anterior lip of the tibia can be subtle, appearing as a convex margin rather than the normal concave one (Fig. 16.5). Both these spurs are intracapsular, although this may be difficult to appreciate on a plain X-ray. Differential diagnosis
This mainly associated with early OA of the ankle. It should be noted, though, that in a true footballer's ankle the articular surfaces are normal when these bony spurs are removed surgically (Case history 16.1).
Presenting symptoms
Because of the aetiology the diagnosis may be missed acutely and the patient treated for a simple sprain or malleolar fracture. If, however, symptoms persist after adequate treatment of the recognised injury, an osteochondral fracture should be suspected. Acute symptoms will be those of a sprained ankle, with the patient complaining of pain, swelling and difficulty walking. Chronic symptoms are more general, with patients complaining of discomfort, pain and perhaps stiffness during or after exercise. If an osteochondral fragment has become detached from the talar dome, then there may be locking and giving way in the ankle, suggestive of a loose body.
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SPECIFIC CLIENT GROUPS
Signs
Acute signs will include swelling and tenderness over the lateral ligament complex with pain on inversion of the ankle. It may be possible to locate tenderness over the talar dome midlaterally or behind the medial malleolus. Investigations
AP, lateral and oblique (l0° of medial rotation) plain X-rays of the ankle should initially be requested. Lateral lesions classically are shallow, horizontal and often detached or elevated. Medial lesions are frequently cup-shaped and deeper (Canale & Belding 1980), shown by line drawing in Figure 16.6. In the acute stage X-rays may appear normal, especially if the lesion is stage I, i.e. only the articular cartilage is damaged (Berndt & Harty 1959). Even in a chronic lesion it may be difficult to detect any changes on plain X-ray. A bone scan is extremely useful as it will usually be positive. Magnetic resonance imaging (MRI) is the most sensitive, as well as the most expensive way of demonstrating
the osteochondral fractures. Blood tests are of no value in the investigation of this condition. Differential diagnosis
Acutely, this will be the coexistent trauma. Chronically, it will be other conditions around the ankle such as anterolateral impingement syndrome, tendonitis of any of the tendons crossing the ankle joint and early GA.
Hallux rigidus Aetiology
Hallux rigidus is a condition in which dorsiflexion of the MTPJ of the hallux is restricted and painful on movement. Plantarflexion may also be limited but dorsiflexion is the functional movement affected by the pathology. It may occur secondary to an osteochondritis dissecans of the first metatarsal head in adolescents, usually females. In adults, males tend to predominate and it can be secondary to a systemic disease such as RA or gout, but most commonly is primarily due to a local arthritic degeneration. Various theories have been advanced for the primary cause, such as a long first metatarsal and hallux and repeated minor trauma; patients tend to have pronated, narrow, long feet with a flat longitudinal arch. Hallux plexus was a term originally used to describe hallux rigidus. It is now used in connotation with a severe form where the proximal phalanx becomes flexed at the MTPJ and the first metatarsal becomes secondarily elevated. Presenting symptoms
Intermittent pain in adolescents, who may experience episodes of acute pain made worse by walking. Adults present with pain on walking, stiffness and pain over the dorsal exostosis in more advanced cases, although lateral joint pain may be observed as well. Figure 16.6 Osteochondritis dissecans: line drawing of anterior view of the ankle mortice. Lateral lesions tend to be horizontal and shallow, medial ones tend to be deeper and cup-shaped.
Signs
The hallux is commonly straight and a dorsal bony prominence, with perhaps a bunion (soft
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407
bursa swelling), may be found. Locally there may be some tenderness over the exostosis and around the first MTPJ. The range of movement should be assessed with the foot in a plantigrade position but also in a plantarflexed position. A grind test, in which the hallux is compressed longitudinally with rotation, may be painful where the joint is not stiff. In advanced cases compensatory secondary hyperextension of the interphalangeal joint (IPJ) may be found and commonly there is a callosity on the medial plantar aspect of the head of the proximal phalanx or base of the distal phalanx. Investigations
Plain X-rays of the first MTPJ may be normal or show a dorsal exostosis with a normal-looking joint. In more advanced cases degenerative changes will be apparent with progressive OA. If hallux rigidus is due to gout or RA then periarticular erosions may be present with osteoporosis. Blood tests are only indicated if a systemic disease is suspected. Differential diagnosis
In flexor hallucis longus tenosynovitis, dorsiflexion of the hallux may be restricted and painful. Resisted plantarflexion of the hallux will be painful and local tenderness may be felt posterior to the medial malleolus.
Accessory ossicles Aetiology
There are at least 15 accessory ossicles around the foot and ankle (Romanowski & Barrington 1991). Most are anatomical variants in origin (see Fig. 11.18). Only two are rarely likely to cause symptoms. Around the hindfoot there is the as trigonum, on the posterior aspect of the talus close to the lateral tubercle, and the accessory navicular (Fig. 16.7 and see Fig. 11.19). The type II accessory navicular is roughly 1 em in size and united to the main body of the navicular by a synchondrosis of about 12 mm (Romanowski & Barrington 1991).
Figure 16.7 view.
X-ray showing accessory navicular - dorsiplantar
Presenting symptoms
The os trigonum causes symptoms with activities in repeated plantarflexion, affecting football players and dancers standing 'en pointe'. Patients complain of posterolateral ankle pain when the ankle is plantarflexed and impingement occurs. An accessory navicular may cause rubbing in a shoe, because of local pressure, or may become symptomatic following a twisting injury to the foot. Signs
With a symptomatic os trigonum tenderness may be felt behind the lateral malleolus and peroneal tendons and forced passive plantarflexion of the ankle will be painful. When an accessory navicular is present there will be local tenderness in association with a prominent navicular and perhaps pain on resisted inversion. Investigations
Plain X-rays will demonstrate the presence of accessory ossicles but their presence is not proof
408
SPECIFIC CLIENT GROUPS
------------------------------
of their guilt. A bone scan may help to demonstrate a symptomatic os trigonum. Differential diagnosis
A symptomatic os trigonum may be mistaken for peroneal tendonitis, flexor hallucis longus tendonitis or a fracture of the lateral process of the posterior talar tubercle. A symptomatic accessory navicular is usually obvious because of local tenderness but should not be confused with tibialis posterior tendonitis.
Stress fractures
and up to 5 weeks for calcaneal ones. In the metatarsal shafts early changes may be a fine line of bone resorption followed either by sclerosis or periosteal callus, depending on whether the cortex has been breached. In the calcaneum the fractures tend to occur in the posterior part and appear as endosteal callus with an intact cortex on X-ray. Because of the delay in plain radiographs a bone scan may be helpful if there is doubt about the diagnosis. Computed tomography (CT) or magnetic resonance imaging (MRI) scans may be helpful to show stress fractures which are difficult to depict on plain X-ray.
Aetiology
Stress fractures occur due to overuse in unadapted feet or when surgery in the foot leads to high stresses elsewhere. Fractures have been reported in groups such as runners, army recruits and dancers. They may also occur, though rarely, after first ray surgery, e.g. Keller's excisional arthroplasty operation, which increases stresses on the lesser metatarsals. From whatever cause the most common site is a metatarsal shaft. Stress fractures have also been reported in the calcaneus, navicular, cuboid and proximal phalanx of the hallux. Presenting symptoms
Pain occurs in relation to activity. Initially it may be vague and difficult to localise but settles on rest. With time the patient may complain of a limp.
Differential diagnosis
The clinical picture, relation to activity and local tenderness should point towards the correct diagnosis. One should beware of metatarsal 'stress fractures' in the diabetic as they may be the precursor of a Charcot foot.
Subungual exostosis Aetiology
This is a bony spur usually ansmg from the dorsomedial aspect of the distal phalanx of the hallux. Rarely it may arise from the lesser toes. It is generally a benign osteochondroma, congenital in origin, and may be noticed from adolescence up to early middle age. There is some suggestion that those occurring in young adult athletes may be the result of repetitive minor trauma inside the shoe.
Signs
In the early stages there may be little to find on clinical examination but if activity continues then local tenderness and swelling will develop. A limp may be present.
Presenting symptoms
Patients may notice a swelling under the nail or may complain of pain on walking or running with shoes on.
Investigations
Plain X-rays may often be normal in the early stages and it can be 2-3 weeks before changes become apparent for metatarsal stress fractures
Signs
The nail may be elevated and there may be a darkish discoloration, resembling a haema-
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toma, apparent under the nail. The distal nail edge may be elevated, suggesting an enlarged distal tuft. Investigations
Plain X-rays will show the exostosis. Medial oblique views are most helpful but DP and lateral may be required to establish the extent of the projection. As cartilage is not radio-opaque, the practitioner should not be lulled into thinking that the swelling is small (see Fig. 11.32). Differential diagnosis
A subungual exostosis may be confused with other conditions, such as a glomus tumour or subungual wart.
Tarsal coalition Aetiology
This is a congenital condition, inherited as an autosomal dominant trait, in which adjacent tarsal bones have a fibrous, cartilage or bone connection or bridge which progressively restricts normal movement. This may be termed syndesmosis, synchondrosis or synostosis, respectively, and occurs in less than 1 % of the population (Mosier & Asher 1984). Generally, it begins as a fibrous union in infancy and progresses to cartilaginous and then bony union; however, it may remain fibrous. The most common coalition is probably talocalcaneal, followed by calcaneonavicular (Stormont & Peterson 1983). Although rare, most other possible combinations have been described.
409
Signs
Stiffness in the subtalar or midtarsal joint movements is usually the predominant sign. Patients may also have a valgus flatfoot with subtalar irritability, characterised by pain on forced plantarflexion of the ankle joint and some peroneal spasm. In childhood, presentation like this is known as peroneal spastic flatfoot. Investigations
Appropriate plain X-rays may demonstrate a coalition; DP, lateral and medial oblique films should be taken. Medial oblique views show the calcaneonavicular coalition (Fig. 16.8). A Harris axial view may show a talocalcaneal coalition. Dorsal beaking on the head of the talus is a secondary change to abnormal movement, also suggesting this type of pathology (Case history 16.2). A long anterior calcaneal process may indicate a calcaneonavicular coalition, although this coalition is usually well demonstrated on plain films (see Fig. 11.35). If X-rays are not diagnostic then a CT scan in the frontal plane may confirm the diagnosis.
Presenting symptoms
Although these coalitions usually ossify between 8 and 16, symptoms may not develop until late childhood or into adulthood. Sometimes patients never develop symptoms and the diagnosis is made incidentally. When they do present, patients may complain of stiffness and ankle pain where playing sport. They may also complain of recurrent ankle sprains.
Figure 16.8 X-ray illustrating calcaneonavicular coalitionmedial oblique view.
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SPECIFIC CLIENT GROUPS
---~----~----~-------------~~~~---------------~
r-------------------
I
-----1
Case history 16.2
I
Patient: 25-year-old female. Presenting symptoms: The patient has a history of bilateral flat feet since childhood. She was now getting pain on walking after half a mile which was interfering with normal living. Signs: There was a normal range of movement in both ankle joints but both subtalar joints were rigid; there was slight decreased range of movement in the midtarsal joints bilaterally. Investigations: Plain X-rays showed talar beaking bilaterally. A CT scan showed bony left talocalcaneal fusion. On the right there was virtual talocalcaneal apposition but bony fusion could not be demonstrated and a fibrous union was surmised. Diagnosis: Bilateral talocalcaneal tarsal coalition with secondary arthritic changes in the midtarsal joints. Operative: Planned staged triple arthrodeses to give the patient plantigrade pain-free feet for walking.
illustrates the effect of hallux valgus on the forefoot. • A prominent fibular (lateral) condyle on a metatarsal head may cause a very local plantar callosity with pain on weightbearing. • Proximal stiffness of malalignment, e.g. a pes cavus foot, may lead to excessive loading on one side of the foot. Presenting symptoms
Patients complain of pain under the ball of the foot on walking, made worse by walking barefoot. Well-padded shoes such as trainers can reduce symptoms effectively. Patients may also complain of hard skin continually building up under the foot, which adds to the general discomfort.
Differential diagnosis
Signs
Other conditions leading to stiff subtalar or midtarsal joints, such as degenerative or inflammatory arthritis.
The main sign is tenderness under the metatarsal heads on palpation; callosities may be present under the symptomatic heads, indicating the increased load. With a prominent fibular condyle the callosity is small and well-defined and has a
Metatarsalgia Aetiology
Metatarsalgia is characterised by pain felt under one or more metatarsal heads when weightbearing. It may be due to a number of causes:
• Atrophy of the plantarfat pad with age. This results in a generalised metatarsalgia because of loss of the cushioning effect of the fat pad. • Increased pressure under the lesser metatarsals following first MTPJ surgery, e.g. for hallux valgus of Keller's operation. • Metatarsophalangeal joint problems. Subluxation or dislocation of the proximal phalanx may lead to a pistoning effect which depresses the metatarsal head, increasing its load. This may occur in inflammatory arthropathies or in a cavus foot with claw toes. Claw toes that dorsiflex on the metatarsal head pull the fat pad forward, exposing the metatarsal head to greater loading during stance. Case history 16.3
Patient: 58-year-old garage mechanic. Presenting symptoms: The patient presented with a large bunion on his left foot and discomfort under the centre of the ball of his foot on walking. Signs: A gross hallux valgus was present, along with pronation of the hallux. There was some callosity formation under the second and third metatarsal heads. The rest of the foot was normal. Investigations: Plain x-rays showed hallux valgus of 55° with lateral subluxation of the proximal phalanx at the first MTPJ. Some minor degenerative changes were present in this joint. Diagnosis: Gross hallux valgus with secondary transfer metatarsalgia due to unloading of the first ray. Operation: Arthrodesis of the first MTPJ to correct the hallux valgus and allow better weightbearing through the first ray, thus relieving the transfer metatarsalgia. Usually a secondary reduction in the hallux valgus is difficult with realignment (osteotomy) operations. Postoperatively the patient's symptoms were relieved.
THE PAINFUL FOOT
central keratotic core. This may be described as a localised intractable plantar keratoma. The other type of callosity observed will be a diffuse lesion without a central keratotic core. Prominent metatarsal heads may be palpated and their degree of rigidity should be assessed, as should the mobility of the toes. It is important to access the mobility of the proximal joints to ensure they are supple. Investigations
Plain X-rays will demonstrate evidence of any inflammatory arthropathy and any changes in a metatarsophalangeal joint. If available, dynamic pressure studies will show the distribution of pressure under the metatarsal heads. The plain X-ray view has not been shown to provide an objective measurement of metatarsal plantarflexion in the case of lesser metatarsals. Differential diagnosis
This lies between the various causes of metatarsalgia. A wart may cause a plantar callosity but does not normally occur under a metatarsal head. A Morton's neuroma is commonly referred to as Morton's metatarsalgia, although the pain and tenderness is actually between metatarsals, radiating into toes (digital neuritis).
Sesamoiditis Aetiology
Flexor hallucis brevis inserts into the base of the proximal phalanx of the hallux and within its tendons two sesamoid bones lie under the first metatarsal head. These may give rise to pain if they become arthritic. This can occur secondary to hallux rigidus or inflammatory arthropathies such as rheumatoid arthritis. Chondromalaciatype changes have also been reported. Rarely, sesamoids may fracture following trauma and stress fractures have been reported. Hypertrophy of a sesamoid can lead to a painful plantar callosity.
411
Presenting symptoms
Pain under the first metatarsal head on weightbearing is the main symptom; patients may notice this particularly on toe-off. Signs
Tenderness may be localised to one or both sesamoids. Extension at the first MTPJ may be limited and painful and a plantar callosity may be present. Investigations
A standing DP and lateral X-rays should be taken and also a skyline view of the sesamoids. If X-rays are normal a bone scan may be helpful. Differential diagnosis
Other causes of pain around the first MTPJ, such as hallux rigidus. The high incidence of bipartite sesamoids (figures vary from 10 to 30%) may lead to a false diagnosis of a fracture (Hubay 1949).
Tumours Aetiology
Bony or cartilaginous tumours are fortunately rare in the foot. Nevertheless, a number have been reported, both benign and malignant. Among the most common benign ones are osteoid osteoma, enchondroma and osteochondroma. Osteoid osteomas may occur in the tarsus in the foot, enchondromas in metatarsals or phalanges and osteochondromas normally only occur as subungual exostoses (Fig. 16.9). Malignant tumours reported include osteosarcoma, chondrosarcoma and Ewing's tumour. Osteosarcomas and chondrosarcomas have been reported in the tarsus and metatarsals, Ewing's in the tarsus. Although a secondary deposit is the most common bony tumour in the body as a whole, secondaries are rare in the foot but may occur: if they do, the most likely primary is a bronchial carcinoma.
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SPECIFIC CLIENT GROUPS
Differential diagnosis
The first consideration with any lesion suspected of being a tumour is whether it is benign or malignant. Infection should always be considered as it may sometimes be difficult to differentiate. Although it should not cause any confusion in diagnosis, an old fracture may sometimes look suspicious to the untutored eye.
SOFT TISSUE, TENDONS AND LIGAMENTS Figure 16.9 Subungual exostosis on dorsum of third toe with gross nail displacement.
Presenting symptoms
This will depend on the individual tumour. Osteoid osteomas tend to occur in young adults and classically give rise to night pain relieved by aspirin. Enchondromas may cause cortical thinning of a metatarsal and therefore present with acute pain from a pathological fracture. Malignant tumours may present with pain and/ or swelling.
Tendonitis Aetiology
Peritendonitis may affect any of the tendons crossing the ankle into the foot but most commonly involves the tendo Achilles and tibialis posterior. Achilles tendonitis occurs usually in young adults who are joggers or athletes. Tibialis posterior tenosynovitis (inflammation of its tendon sheath) normally occurs in late middle age. Less commonly, tenosynovitis of a peroneal tendon may occur and in dancers tenosynovitis of the flexor hallucis longus tendon can occur where it passes in a groove behind the talus.
Signs
These depend on the diagnosis and may vary from nil to tenderness and swelling from a pathological fracture. Investigations
Plain X-rays will demonstrate most of these lesions, showing areas of bone destruction, expansion or new bone formation. An osteoid osteoma may be seen as a central nidus with surrounding sclerosis, but can be very difficult to see and a bone scan may help by showing it as a concentrated hot spot. MRI is extremely helpful both in diagnosis and delineating the extent of a malignant tumour. Before any definitive treatment is planned a biopsy of the tumour is usually necessary. As well as imaging bony tumours, a full blood screen will usually be performed, along with a chest X-ray and bone scan, unless the tumour is simple and benign.
Presenting symptoms
Patients with peritendonitis will present with pain on exercise, usually along the course of the tendon; they may also notice some swelling. It is worth enquiring whether they have recently changed running shoes. Signs
In Achilles tendonitis the tendon will be painful to palpation about 5 cm proximal to its distal insertion; with time, swelling and crepitus may be found. In tibialis posterior tenosynovitis there will be tenderness behind the medial malleolus with pain on resisted inversion and perhaps passive eversion. It is important to rule out ruptured tibialis posterior tendon. In this case the patient may present with vague pain on the medial aspect and a spontaneous flat foot. The
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hindfoot will be in valgus and the heel will not invert if the patient stands on tiptoe. When looked at from behind, the forefoot is abducted, producing the 'too many toes sign' (Johnson 1983). For the peroneal tendons, tenderness will be felt distal to the lateral malleolus, along the course of the tendons, with pain on inversion and plantarflexion. Differentiating between brevis and longus may be difficult; tenderness on the sole of the foot between the cuboid and base of the first metatarsal will suggest problems with peroneus longus. Evert the hindfoot actively against resistance to clarify such involvement. In tenosynovitis of flexor hallucis longus there will be tenderness posterior to the medial malleolus with pain on passive extension of the hallux. Occasionally, tenderness can be found at the level of the sesamoids and may cause limitation of movement at the first MTPJ.
Presenting symptoms
The patient may complain of a painful snapping sensation at the ankle on certain movements. Signs
There will be tenderness along the peroneal tendons behind the lateral malleolus and the tendons may sublux anteriorly with resisted eversion and dorsiflexion. Investigations
Again, this is mainly a clinical diagnosis but if doubt exists then a peroneal tenogram may show dye leakage, indicating a torn retinaculum. Differential diagnosis
Acutely with a sprained ankle and more chronically with peroneal tenosynovitis.
Investigations
Chronic ankle sprain
Peritendonitis is largely a clinical diagnosis; if doubt exists then MRI may be helpful in showing fluid in the tendon sheath. Abolition of the patient's symptoms by injection of local anaesthetic may also be diagnostic.
Aetiology
Differential diagnosis
In Achilles tendonitis it is important not to miss a rupture. Up to 25% of acute ruptures are missed (Lutter 1991). Similarly, with tibialis posterior tenosynovitis, rupture should be looked for. Tenderness at the insertion may be due to an accessory navicular.
Subluxing peroneal tendons Aetiology
The peroneal tendons are held behind the lateral malleolus by the retinaculum and this may be ruptured in an acute injury. Following that the tendons are free to sublux.
413
Chronic lateral pain following an acute inversion injury of the ankle is common, being reported in up to 50% of some patient groups (Ferkel et al 1991). This may be due to residual instability, causing recurrent sprains, but most commonly is due to soft tissue impingement in the lateral gutter. The initial sprain leads to inflammation, synovitis and then scar tissue and fibrosis. Presenting symptoms
Patients complain of pain over the anterolateral aspect of the ankle on walking, and often weakness and a feeling of giving way. Signs
Tenderness is present over the anterolateral gutter of the ankle. Ankle and subtalar joint movement is usually normal. Instability should be carefully looked for. Clinically, this is done by comparing inversion between the two ankles and
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doing an anterior drawer test. In this test the patient lies supine with the knee flexed and the examiner sits on the patient's foot to stabilise it. The tibia is then pushed back on the talus. Instability is shown by excessive movement by comparison to the other ankle. A clunking sensation may be elicited sometimes. This may be a difficult test to do without the patient fully relaxed under a general anaesthetic. Investigations
Plain X-rays are usually normal but may show small bony spurs or calcification. Stress X-rays for instability will be normal. A bone scan may show mildly increased uptake and is only useful in excluding other causes of pain. MRI is the only tool which can show increased soft tissue in the lateral gutter. Differential diagnosis
Other local causes of pain should be excluded, such as an osteochondral fracture, peroneal tendon problems and arthritis of the ankle joint.
Sinus tarsi syndrome Aetiology
This condition was first described in 1958 by O'Connor, but has remained somewhat nebulous (O'Connor 1958). It follows a sprained ankle which does not resolve in the normal time and may be due to degeneration of the fatty soft tissue in the sinus tarsi. Although such changes have been shown, in O'Connor's original series of 14 patients treated operatively histology of excised tissue was normal. Some practitioners consider that the condition represents a mild form of subtalar instability. Presenting symptoms
The patient will complain of chronic pain, situated laterally, following a sprained ankle.
Signs
Apart from tenderness over the sinus tarsi, there is little to find. Investigations
Plain X-rays will be normal. An injection of local anaesthetic into the sinus tarsi should provide some temporary relief of symptoms and is diagnostically useful. Differential diagnosis
Other causes of continued pain following a sprained ankle.
Compartment syndrome Aetiology
The muscles and nerves in the leg are contained within four compartments, each of which has fascial or fascial and osseous boundaries. The foot also has four compartments. A compartment syndrome results from ischaemia to muscles, and may involve nerves, secondary to raised pressure within that compartment. It may occur acutely following a fracture or soft-tissue trauma or chronically with symptoms after a certain level of exercise. Mild compartment syndromes are not infrequently missed following a fractured tibia and present with residual sequelae such as claw toes. Chronic compartment syndromes only will be discussed. Presenting symptoms
Chronic compartment syndromes of the leg will present with pain in the involved compartment after a degree of exercise, usually running. The pain settles on rest but symptoms may become worse with time. If the anterior compartment is involved, then pain and paraesthesia may radiate into the dorsum of the foot and ankle from involvement of the superficial peroneal nerve. If the deep posterior compartment is involved, then pain and paraesthesia over the sole of the foot, in the distribution of the posterior tibial nerve, may be felt.
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415
Signs
At rest physical examination may be normal, although there may be some tenderness over the distal tibia. This may become more marked if the patient exercises on a treadmill to produce symptoms.
r .•i iii ii\ \\--uiliilimc---+--- tibial Posterior nerve
f>
",,",-~--\--
Flexor retinaculum
Investigations
Plain X-rays should be taken to exclude a stress fracture or other osseous causes of leg pain. Measuring compartment pressures with a catheter introduced under local anaesthetic is the most useful way to confirm the diagnosis. Pressures are measured before and after exercise. There is some debate as to the correct abnormal compartment pressures. Generally, intracompartmental pressures at rest should be less than 15mmHg and 5-10 min following exercise should have returned to 15 mmHg or less (Pedowitz et aI1990). Differential diagnosis
Shin splints or stress fractures of the tibia will be the main differential diagnosis for leg pains. For neurological symptoms in the foot an entrapment neuropathy should be excluded.
---Medial and lateral plantar nerves emerging Figure 16.10 Line drawing to show gross anatomy of the tarsal tunnel - lateral view.
pression may cause direct pressure, leading to motor and sensory symptoms, or may compress the vascular supply, the vasa nervorum, causing sensory symptoms only. Aetiology of tarsal tunnel syndrome is idiopathic, trauma or associated with bony alignment (Cimino 1990). Other cases may be related to problems such as rheumatoid arthritis or compression within the tunnel associated with a ganglion, lipoma or venous varicosities.
NERVES
Presenting symptoms
A number of nerves may be compressed at sites around the ankle and foot, resulting in entrapment neuropathies.
The patient is likely to complain of a diffuse, burning type of pain on the sole of the foot. With time symptoms may become more localised. Often pain is worse on activity and better at rest. A proportion of patients get nighttime pain and some 30% have proximal radiation of pain to the midcalf region, known as the Valleix phenomenon (Mann 1993).
Tarsal tunnel syndrome Aetiology
The posterior tibial nerve, a branch of the sciatic nerve, may become compressed as it passes under the flexor retinaculum behind the medial malleolus (Fig. 16.10). Interestingly, tarsal tunnel syndrome is a relatively new diagnosis, having only been properly first described in 1962 (Keck 1962, Lam 1962). The condition is analogous to carpal tunnel syndrome in the wrist but nowhere near as common. The com-
Signs
Sensory or motor weakness is rare to find but should be carefully looked for. Most useful is a positive Tinel sign, obtained by starting proximally and percussing along the course of the nerve. At the site of entrapment percussion will cause radiation of pain along the course of the nerve.
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Investigations
Plain X-rays may demonstrate any post-traumatic bony spurs causing compression but do not in themselves make a diagnosis. Electrodiagnostic tests are necessary for this: nerve conduction studies looking at sensory conduction velocities and the amplitude and duration of motor-evoked potentials (Ch. 7). Tests should be performed bilaterally and a peripheral neuropathy should be excluded. If an extrinsic compression in the tunnel is suspected then an MRI may be helpful. Differential diagnosis
Because of the diffuse nature of the symptoms the differential diagnosis is quite wide, but two possibilities should be particularly looked for. A peripheral neuropathy, e.g. from diabetes, may cause burning pains in the foot, but is usually bilateral. Sciatica with nerve root irritation causing distal pain also needs to be excluded. Straight leg raising will be restricted and painful.
Other entrapments Aetiology
Other entrapments which have been described include the deep peroneal nerve under the inferior extensor retinaculum and the superficial peroneal nerve as it exits the deep fascia about 11.5em above the lateral malleolus, the medial plantar nerve at the master knot of Henry and the first branch of the lateral plantar nerve between abductor hallucis and quadratus plantae muscles. Most of these entrapments occur in runners or athletes. Symptoms and signs Deep peroneal nerve. Patients complain of pain over the dorsum of the foot and sometimes numbness and paraesthesia in the first web space. There may be altered sensation in the first web space and a positive Tinel sign. Superficial peroneal nerve. Symptoms include pain over the dorsum of the foot and ankle and
inferior lateral border of the calf. As a sensory nerve there are no motor signs but there may be a positive Tinel sign. A fascial defect or muscle herniation where the nerve exits the deep fascia should be looked for. Medial plantar nerve. Patients complain of an aching pain over the medial aspect of the arch, often radiating into the medial three toes, becoming worse on running. Again, a positive Tinel sign may be found and also tenderness under the medial arch (Case history 16.4). First branch of lateral plantar nerve. Patients complain of chronic pain, often increased on running but sometimes present on waking. On examination there will be tenderness over the nerve deep to abductor hallucis and pressure reproduces the patient's symptoms. Investigations
Nerve conduction studies may help with the diagnosis of deep peroneal nerve entrapment, but are less useful in diagnosing the others. More - - - - - - - _ . _ - -..
Case history 16.4
;
1-------------------------_
1
Patient: 48-year-old keen runner; squash and badminton player.
Presenting symptoms: 18-month history of bilateral paraesthesia affecting the medial aspect of the soles of both feet, in the distribution of the medial plantar nerve, when running. Symptoms initially settled after exercise but over the next 6 months the patient developed shooting pains without any pattern of onset with increasing numbness in both feet. Signs: A positive Tinel sign above both medial malleoli. Some loss of sharp and blunt sensory discrimination on the medial aspect of the sole was identified. Investigations: Nerve conduction studies showed conduction blocks bilaterally at the level of the tarsal tunnel. Medial plantar responses were absent on the right and delayed on the left. Diagnosis: Bilateral tarsal tunnel syndrome. Operative findings: On both sides there was a high division of the posterior tibial nerve into medial and lateral plantar branches. A sharp edge to abductor hallucis was found to be compressing the medial plantar nerve bilaterally. In addition there was a large vascular pedicle crossing the medial plantar nerve and compressing it more proximally. Pain settled following surgery.
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recently, abnormalities of nerve conduction and electromyography have demonstrated plantar nerve abnormalities (Schon et al 1993). Injection of local anaesthetic at the site of entrapment may act as a diagnostic test if it abolishes symptoms. Differential diagnosis
As for tarsal tunnel syndrome.
Peripheral neuropathy Aetiology
Peripheral neuropathies may be due to a variety of causes. In the West the leading cause is diabetes and in the Third World it is leprosy. Other causes include spina bifida, pernicious anaemia, drugs and alcoholism. The different patterns of peripheral neuropathy may vary but in diabetics the most common is a symmetrical distal polyneuropathy, encompassing motor, sensory and autonomic components. Presenting symptoms
Patients may notice no symptoms at all if the neuropathy presents as a painless one. The first inkling of a problem may be when a patient presents with a complication such as ulceration or infection. In a diabetic who normally has a painless foot with no sensation the presence of pain is important and may indicate deep infection, such as an abscess or osteomyelitis. If the presentation is of a painful neuropathy the patient may complain of a burning sensation in the legs and feet, commonly worse at night. Signs
In a diabetic the foot may adopt a cavus appearance with clawed toes. In the absence of vascular disease the foot will feel warm and there may be distended veins. Sensation to light touch and pinprick will be reduced and joint position sense may be impaired. The toes may be clawed with wasting of the intrinsic foot muscles and the ankle jerk absent. Callosities may be present under the metatarsal heads and heel.
417
Investigations
In evaluating a peripheral neuropathy it is important to look for an underlying cause. The urine should be tested for sugar and a random blood glucose test performed to look for the most common cause. A careful history and examination should uncover evidence of other causes. Nerve conduction studies may be helpful to rule out an entrapment neuropathy.
Morton's metatarsalgia (neuroma) Aetiology
This condition is a type of entrapment neuropathy affecting a plantar digital nerve. It most commonly affects the common digital nerve to the 3/4 interspace, but may also occur in the 2/3 interspace. The diagnosis probably does not exist in the first or fourth webspaces, although there has been much debate about this. The incidence of a second neuroma in the same foot is 4% (Thompson & Deland 1993). Women are affected at least four times more often than men and the condition can affect adults of any age. The nerve develops a fusiform swelling, just proximal to its bifurcation, at the level of the intermetatarsal bursa (Fig. 16.11). Although frequently termed a neuroma, technically it is not as the histology shows a degenerative process rather than a proliferative one. Presenting symptoms
The patient complains of a burning pain on the sole of the foot, at the level of the metatarsal heads and commonly radiating into one or two toes. It may feel to the patient like walking on a sharp pebble. Occasionally, pain will radiate proximally. Pain is often worse on walking and may be particularly exacerbated by tight-fitting shoes, as these will compress the metatarsal heads together, thus 'trapping' the nerve. Resting or removing tight shoes may settle the pain. Less than half the patients complain of numbness in the toes.
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SPECIFIC CLIENT GROUPS
Investigations
Plain X-rays should be taken to rule out other pathology. Although ultrasound and MRI have been used to look for the swelling in the nerve they have not generally proved reliable enough to be used as diagnostic tools. Ultrasound has been reported as useful if the neuroma is 5 mm in diameter (Pollak et al 1992). Nerve conduction studies are not helpful. A diagnostic injection of local anaesthetic may be helpful if it abolishes the patient's pain. Differential diagnosis
Problems affecting the metatarsal head, such as synovitis, intermetatarsal bursa and Freiberg's disease, should be considered. It is important to be careful about whether the tenderness is under a metatarsal head or intermetatarsal. Pain from a neurological cause, such as tarsal tunnel syndrome, peripheral neuropathy or referred pain from the back should be excluded.
Figure 16.11 Resected Morton's neuroma showing terminal digital branches following operation.
SKIN AND SUBCUTANEOUS TISSUES Retrocalcaneal bursitis Aetiology
Signs
On palpation of the relevant interspace the patient's pain will be reproduced, sometimes with radiation into a toe. However, it may be difficult to elicit conclusive evidence on examination. If pressure is maintained in the interspace with one hand, while the other alternately squeezes the forefoot from side to side to compress the metatarsal heads together, then a painful click may be obtained. This is known as Mulder's click and is only helpful if it reproduces pain (Mulder 1951). It is important to ensure that any tenderness is not over the metatarsal heads, rather than intermetatarsal, although in rare cases nerves may become entrapped under a metatarsal head. Sensation in the toes is usually normal, but may vary.
There are two bursae at the heel; one is deep to the tendo Achilles and the other lies superficial to its insertion. The deep bursa is infrequently affected but, as it has a synovial lining, symptoms may be early indicators of an inflammatory arthropathy such as rheumatoid arthritis. Men are affected more often than women. Symptoms in the subcutaneous bursa affect adolescent females most frequently. Presenting symptoms
For the subcutaneous bursa the symptoms are well described by some of the eponyms for the condition, sucha as 'pump or heel bumps'. The patient complains of a tender prominence at the heel when wearing shoes (Fig. 16.12).
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419
Predisposing symptoms may be running on hard surfaces, e.g. roads, obesity and increasing age. Presenting symptoms
Patients complain of heel pain, worse in the early morning and on weightbearing. They may have a limp. Signs
There is localised central tenderness under the heel. Figure 16.12 Bilateral heel bumps with superolateral prominence on the heel, also known as Haglund's deformity.
Investigations
This is essentially a clinical diagnosis. X-rays or ultrasonography are not helpful. Signs
Inflammation of the deep bursa will produce tenderness deep to the tendo Achilles. In heel bumps there is variable tenderness over a thickened bursa situated just lateral to the tendo Achilles attachment.
Differential diagnosis
This will include plantar fasciitis and entrapment neuropathies, particularly of the nerve to abductor digiti quinti.
Investigations
Plantar fasciitis
A plain lateral X-ray should be taken. With deep bursitis calcaneal erosions should be looked for. In heel bumps the X-ray is usually normal with no evidence of any posterosuperior prominence to the calcaneus.
Aetiology
Differential diagnosis
This is a chronic inflammation at the site of the attachment of the plantar fascia to the medial tubercle of the calcaneum. It possibly represents a traction periostitis and may be precipitated by overuse and occurs in middle-aged people and with a male predominance.
This is mainly with other causes of heel pain and with Achilles tendonitis.
Presenting symptoms
Heel pad syndrome
Patients complain of pain under the heel on weightbearing; this may be particularly acute on getting up in the morning.
Aetiology
This is a chronic inflammatory process within the heel fat pad. The heel is subject to repetitive impact loading on walking which can exceed body weight; with running these forces can rise to 3-8 times body weight (Riegler 1987).
Signs
There is tenderness along the anteromedial border of the calcaneum which may be increased by passive dorsiflexion of the toes.
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Investigations
The diagnosis is clinical although a bone scan may show increased uptake locally. Plain X-rays may show a spur on the inferior border of the calcaneum but this is equally found in asymptomatic people. Differential diagnosis
As in heel pad syndrome.
Soft tissue masses or tumours Aetiology
Some benign soft-tissue masses, such as ganglions, are common in the foot. A ganglion is a mucoid cyst which usually arises from an underlying joint. In the foot they most commonly occur over the dorsum of the ankle (Fig. 16.13). Plantar fibroma to-
sis is analogous to Dupuytren's contracture in the hand and is a proliferation of the plantar aponeurosis to form discrete nodules, usually in the instep. A glomus tumour is a benign bright red vascular tumour, the size of a small pea, and is usually located subungually or in a web space. Presenting symptoms
A ganglion presents as a painful lump inside footwear. Plantar fibromatosis may present with painful nodules, although often the patient only notices some mild discomfort or simply a swelling. A glomus tumour, however, may present with marked pain. Signs
A ganglion will appear as a mobile subcutaneous lump of variable size. Small ones may appear quite firm, whereas larger ones often have a more spongy feel. The nodules of plantar fibromatosis are felt as firm, fairly immobile nodules, often along the edge of the plantar fascia and under the instep. A glomus tumour will appear as a subungual mass or may be palpated as a small nodule in a web space. Investigations
Plain X-rays may distinguish a glomus tumour from a subungual exostosis; otherwise, the diagnosis is made from clinical information. Differential diagnosis
Multiple ganglions around the extensor tendons on the dorsum of the ankle should arouse suspicion of rheumatoid arthritis. A lipoma may be mistaken for a ganglion and is commonly located on the dorsolateral aspect of the ankle.
GENERAL Crystal arthritis Aetiology Figure 16.13
Large ganglion on lateral aspect of the ankle.
Arthritic changes may be caused by the deposition of crystals within a joint. This may be sodium
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urate crystals in gout or calcium pyrophosphate dihydrate crystals in pseudogout. Gout is a disease characterised by a disorder of purine metabolism and is associated with hyperuricaemia. It may be primary with a strong hereditary factor or be secondary to other problems such as renal failure. Pseudogout is sometimes associated with other metabolic conditions, such as hyperparathyroidism, but otherwise it is idiopathic. Presenting symptoms
Up to 75% of initial attacks of gout affect the big toe (Jacoby & Dixon 1991). The patient complains of acute onset of a swollen, very painful first MTPJ. Pseudogout may present with gout-like attacks but these are usually less severe. About 50% of patients, however, will present with progressive degeneration of joints. In the foot the ankle, subtalar and talonavicular joints are most commonly affected. Signs
In the acute stage of gout the great toe will be swollen, inflamed and very tender (Fig. 16.14). In
421
chronic cases the signs of osteoarthritis will be present. Gouty tophi (deposits of sodium urate) may be found in the cartilages of the ears and in bursae, tendons and soft tissues generally. Investigations
Acutely, the serum uric acid may be raised but acute attacks can occur with a normal uric acid level. Aspiration of joint fluid and examination under a polarising lens will show brightly birefringent needle-like crystals in gout and more pleomorphic rectangular crystals in pseudogout. Chronically, X-rays will show degenerative changes in joints affected. Gout gives a characteristic appearance of sharp, punched-out juxtaarticular lesions, with little reactive sclerosis and no general osteoporosis. Differential diagnosis
Acutely, this will be with acute infection and septic arthritis. Chronic forms will be associated with other causes of degenerative joint disease.
Hereditary and motor sensory neuropathy Aetiology
This condition is also known as peroneal muscular atrophy and was first described by Charcot, Marie and Tooth in 1886. Essentially, it is an inherited neuropathy with a predominantly motor component affecting the lower limbs. Motor weakness begins in the peronei, then the dorsiflexors, and may involve all the muscles below the knee. There may also be sensory changes and involvement of the upper limb. The initial symptoms are usually in childhood but the neuropathy then slowly progresses. The adult may then present with a cavus foot, claw toes and pain and callosities over the metatarsal heads. Fixed deformities may develop with equinus of the forefoot and varus of the hindfoot (Mann 1993). Presenting symptoms Figure 16.14 joint.
Acute gout in the first metatarsophalangeal
This will d"epend on how far the disease has progressed. Initially, the patient may present with
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SPECIFIC CLIENT GROUPS
just a clumsy gait and perhaps a history of recurrent ankle sprains. With time the weakness and changes in the shape of the foot become more apparent. The patient may then complain of footwear problems and pain along the lateral border of the foot because of the varus heel. Signs
In the established case there will be a cavus foot with a high arch, a plantarflexed first ray, clawing of the toes and peroneal and intrinsic muscle weakness. Weakness of other muscle groups should be looked for and the hands examined. Sensory changes, if present, are usually mild. Investigations
A careful clinical examination is important because of the differential diagnosis. Plain Xrays, standing AP and lateral, will show the cavus and demonstrate any degenerative changes when fixed deformities are present. Nerve conduction studies and electromyography are important for accurate diagnosis and to rule out other causes of pes cavus. Differential diagnosis
This is from other causes of pes cavus, which will include idiopathic, muscular diseases such as muscular dystrophy, neurological problems such as cerebral palsy, Friedreich's ataxia, poliomyelitis and spinal cord problems. In addition, pes cavus may be due to residual clubfoot or compartment syndrome.
Infection Aetiology
Infection may occur in the soft tissues, as osteomyelitis in the bone or as septic arthritis in a joint. The cause may be direct inoculation following an open wound, either traumatic or surgically created, or via haematogenous spread. Traumatic or surgical infection may occur at any time but septic arthritis is more likely to occur in the very young or the elderly or
immunocompromised. Bony infections are most commonly due to Staphylococcus aureus but streptococci may also be associated with soft-tissue infections. Presenting symptoms
These will vary according to the tissue involved and degree of infection. Cellulitis will present with pain, swelling and erythema of the involved area. Because the bones are very superficial in the foot, osteomyelitis should always be suspected under any area of eellulites. Septic arthritis is likely to present with exquisite pain on moving a joint, usually the ankle, and with overlying swelling and erythema. However, in the elderly or immunocompromised, symptoms may be strikingly muted, reducing suspicion of an underlying joint infection. In acute septic arthritis or osteomyelitis the patient is likely to have systemic signs of being unwell. Signs
Swelling, tenderness and erythema of the soft tissues will be noted. In septic arthritis there is likely to be marked pain on very limited movement of the joint. If marked local tenderness is elicited over a bony area this should alert you to the possibility of underlying osteomyelitis. If infection spreads to a tendon sheath, causing a tenosynovitis, then passive movement of the tendon will be limited and very painful and tenderness may be present along the length of the tendon. Investigations
Plain X-rays are necessary to exclude or demonstrate osteomyelitis. However, it may take 10 days to show any changes. A bone scan will be positive well before plain X-rays and may help. In septic arthritis a diminution in joint space or adjacent osteomyelitis may be seen. Aspiration of fluid from a joint and Gram stain and culture can provide a diagnosis. Blood cultures should also be done: a full blood count will
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show a raised white cell count and the erythrocyte sedimentation rate (ESR) or C-reactive protein will be high. Obviously, if there is an open discharge with pus then swabs should be taken. Differential diagnosis
Infection is a clinical diagnosis. Usually the question to be decided is whether there is underlying bony or joint infection.
Reflex sympathetic dystrophy (RSD) Aetiology
This is an interesting condition which is poorly understood but results from a dysfunction of the sympathetic nervous system. It can follow trauma, sometimes minor in nature, after a fracture or following surgery. Pain can become so unremitting that the patient wishes amputation and may also develop depression and personality changes.
423
Investigations
Plain X-rays may show osteopenia within a few weeks and subperiosteal bone resorption. A bone scan is very helpful as it will show generalised increased uptake in the affected area. Patients have a characteristic delayed bone scan pattern of diffuse increased tracer throughout the foot, with juxta-articular uptake accentuation (Holder et al 1992). Temporary pain relief from a lumbar sympathetic block is also a useful test, although a negative test does not exclude RSD. Case history 16.5 belies some of the problems of treating and diagnosing this pain syndrome early. Both psychological and organic problems can arise, making the problem intractable.
Case history 16.5
Presenting symptoms
Patients complain of a burning pain, often out of proportion to the injury. Initially, this will be due to the trauma of surgery but, instead of settling, the pain increases and becomes the dominant complaint. Pain can occur at rest, with movement and may well trouble the patient at night. The weight of blankets on the bed, or even a sheet, may be intolerable. As well as affecting the injured area, the patient may experience pain over the whole foot in a global distribution. Signs
These may vary according to the stage of the condition. The limb may be swollen and may have a shiny dry appearance. There may be hair and nail changes, joint stiffness and sudomotor changes, with dry skin or excessive sweating. The affected area may become very sensitive and even light touch may evoke considerable and prolonged pain. Because of muscular spasm, patients may develop fixed equinus at the ankle or claw toes.
Patient: A 13-year-old schoolgirl presented following a nail surgery (phenolisation) with positive subungual exostosis over the left hallux. This was confirmed by X-ray. Following an exostectomy to remove the bone, intractable pain developed in a pattern unusual for postoperative events. Presenting symptoms: Pain following two operations at 6 weeks. Stabbing and crushing pain was described, with extreme sensitivity over the foot. Signs: The foot was swollen and blue. Analgesics were of minimal help. The patient had a tendency to hysterical fits. Over an 18-month period the contralateral side became affected. Investigations: Infection was excluded. Surgery was performed on two further occasions by different surgeons in case an exostosis was still present. Amitriptyline 10 mg at night provided minimal help in reducing vasomotor activity. A lumbar sympathectomy (guanethidine) only gave temporary relief. Psychiatric assessment was considered. Diagnosis: Reflex sympathetic dystrophy with hysteria. Conclusion: This case history highlights the ease with which inappropriate management and additional physical insult can elevate the patient's problem. RSD is a difficult problem to manage and non-invasive techniques should be emphasised, with total painblocking control and maintenance of mobility if the pain syndrome is diagnosed (Tollafield 1991).
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Differential diagnosis It can be difficult sometimes to decide if mild RSD is present or if the patient simply has a very painful injury, or one is missing a component of that injury.
and tenderness in the buttock. Straight leg raising will be restricted and causes pain in the distribution of the nerve root. Sensory changes and muscle weakness appropriate to that nerve root may be found but not invariably. Reflexes may be diminished; the knee jerk is L3/4 and the ankle jerk is L5/Sl.
Referred pain Aetiology
Investigations
Referred pain has been mentioned in connection with compartment syndrome involving the deep peroneal and posterior tibia nerves. The main source of referred pain, however, is sciatica due to nerve root compression in the back. Most commonly this is due to a prolapsed intervertebral disc and over 90% of these occur at the L4/5 or L5/S1Ievels.
Plain X-rays should be taken of the lumbosacral spine. If surgery is contemplated, or the diagnosis is unclear, then an MRI scan or CT scan is necessary.
Presenting symptoms
Patients will usually complain of low back pain radiating into a buttock and down the leg. They may have little back pain and mainly leg pain. A careful history may indicate the nerve root involved. Pain radiating down the back of the leg into the sole of the foot is generally Sl in origin and down the lateral border of the leg and into the hallux is generally L5 in origin. Signs
In an acute disc prolapse the patient experiences considerable pain and is unable to move easily. He may have a scoliotic tilt to the spine when viewed from behind, paraspinal muscle spasm
Differential diagnosis
The symptomatology is usually clear but back pain is very common and a more distal problem coexisting with long-standing back pain and sciatica should always be considered.
SUMMARY There are many causes of foot pain. Knowledge of the methods of quantifying and monitoring pain will aid the practitioner in his understanding of this most elusive construct. It has been highlighted that pain is subjective and is a very personal experience, and that the pain associated with certain foot conditions can manifest at various levels. Practitioners must undertake a careful history, examination and relevant investigations, and an appropriate monitoring tool must be selected to chart the progress of any pain manifestation.
REFERENCES Bennett P J, Patterson C 1998 The Foot Health Questionnaire (FHSQ): a new instrument for measuring outcomes of foot care. Australian Journal of Podiatric Medicine 32(3): 87-92 Bennett P J, Patterson C, Wearing S, Baglioni T 1998 Development and validation of a questionnaire designed to measure foot-health status. Journal of the American Podiatric Medical Association 88(9): 419-428 Berndt A L, Harty M 1959 Transchondral fractures (osteochondritis dissecans) of the talus. Journal of Bone and Joint Surgery 41-A: 988-1020
Bowling A 1995 Measuring disease: a review of diseasespecific quality of life measurement scales. Open University Press, Buckingham Budiman-Mak E, Conrad K J, Roach K E 1991 The Foot Function Index: a measure of foot pain and disability. Journal of Clinical Epidemiology 44: 561-570 Canale S T, Belding R H 1980 Osteochondral lesions of the talus. Journal of Bone and Joint Surgery 60-A: 97-102 Cimino W R 1990 Tarsal tunnel syndrome: a review of the literature. Foot and Ankle 11: 47-52
THE PAINFUL FOOT 425
-----------------De Smet A A, Fisher D R, Burnstein M I et al 1990 Value of MR imaging in staging osteochondral lesions of the talus (osteochondritis dissecans). American Journal of Roentgenology 154: 555-558 Ferkel R D, Karzel R P, Del Pizzo W et al1991 Arthroscopic treatment of anterolateral impingement of the ankle. American Journal of Sports Medicine 19: 440-446 Holder L E, Cole L A, Myerson M S 1992 Reflex sympathetic dystrophy in the foot: clinical and scintigraphic criteria. Radiology 184(2): 531-535 Hubay C A 1949 Sesamoid bones of the hands and feet. American Journal of Roentgenology 61: 493-505 Jacoby R K, Dixon A StJ 1991 The painful foot in systemic disorders. In: Klenerman L (ed) The foot and its disorders, 3rd edn. Blackwell Scientific Publications, Oxford Johnson K A 1983 Tibialis posterior tendon rupture. Clinical Orthopaedics and Related Research 177: 140-147 Johnson K D 1987 Management of malunion and nonunion of the tibia. Orthopaedic Clinics of North America 18: 157-172 Keck C 1962 The tarsal tunnel syndrome. Journal of Bone and Joint Surgery 44-A: 180-182 Lam S J S 1962 The tarsal tunnel syndrome. Lancet 2: 1354-1355 Lutter L D 1991 Achilles tendon rupture. AAOS fourth annual comprehensive foot and ankle course McCaffery M, Beeke A 1989 Pain: clinical manual for nursing practice. C V Mosby, Toronto McMurray T P 1950 Footballers ankle. Journal of Bone and Joint Surgery 32-B: 68-69 Mann R A 1993 Diseases of the nerves. In: Mann R A, Coughlin R J (ed) Surgery of the foot and ankle, 6th edn. C V Mosby, St Louis Melzack R 1975 The McGill Pain Questionnaire: major properties and scoring methods. Pain 1: 277-299 Merchant T C, Dietz F R 1989 Long term follow-up after fractures of the tibial and fibular shafts. Journal of Bone and Joint Surgery 71-A: 599-606 Moiser K M, Asher M 1984 Tarsal coalitions and peroneal spastic flat foot. A review. Journal of Bone and Joint Surgery 66-A: 976-984
Mulder J D 1951 The causative mechanism in Morton's. Journal of Bone and Joint Surgery 33-B: 94-95 Nicoll E A 1964 Fractures of the tibial shaft. A survey of 705 cases. Journal of Bone and Joint Surgery 46-B: 373-387 O'Connor D 1958 Sinus tarsi syndrome. A clinical entity. Journal of Bone and Joint Surgery 40-A: 720 Pedowitz R A, Hargens A R, Mubarak S Jet al1990 Modified criteria for the objective diagnosis of chronic compartment syndrome of the leg. American Journal of Sports Medicine 18: 35-40 Pollak R A, Bellacosa R A, Dornbluth N C et al 1992 Sonographic analysis of Morton's neuroma. Journal of Foot Surgery 31(6): 534-537 Price P 1996 Defining and measuring quality of life. Journal of Wound Care 5(3): 139-140 Reigler H E 1987 Orthotic devices for the foot. Orthopaedic Review 16: 27-37 Romanowski C A J, Barrington N A 1991 The accessory ossicles of the foot. Foot 2: 61-70 Saag K G, Saltzman C L, Brown K, Budiman-Mak E 1996 The Foot Function Index for measuring rheumatoid arthritis pain: evaluating side-to-side reliability. Foot and Ankle International 17(8): 506-510 Schon L C, Glennon T P, Baxter D E 1993 Heel pain syndrome: electrodiagnostic support for nerve entrapment. Foot and Ankle 14: 129-135 Stewart A L, Ware J E (eds) 1992 Measuring functioning and well-being: the medical outcomes study approach. Duke University Press, Durham, North Carolina Stormont D M, Peterson H A 1983 The relative incidence of tarsal coalition. Clinical Orthopaedics and Related Reasearch 181: 28-36 Sutherland J E, Wesley R M, Cole P M 1988 Differences and similarities between patient and physician perception of pain. Fam Med 20: 243-246 Thompson F M, Deland J T 1993 Occurrence of two interdigital neuromas in one foot. Foot and Ankle 14: 15-17 Tollafield 1991 Reflex sympathetic dystrophy in day case foot surgery. British Journal of Podiatric Medicine 3(1): 2-6
CHAPTER CONTENTS
Introduction 427 The at-risk foot
The at-risk foot
427
Tissue viability 429 Factors essential for tissue viability 429 Factors which can result in loss of tissue viability 429 Classifying loss of tissue viability 430 Aetiological classification 431 Approachesto determining degree of risk Holistic overview 433 Local indicators 435 Systems approach to risk assessment 438
W. Turner J. McLeod Roberts
433
Clinical decision making 447 Summary 448
INTRODUCTION Increasingly, assessment and subsequent management of the high-risk patient is forming a major part of the practitioner's workload. As the population ages and more people live to old age, the incidence of conditions which place the foot at risk increase. Furthermore, a restructuring of clinical caseloads to focus service delivery to those in greatest medical need is resulting in high-risk case mixes. Knowledge of factors which increase risk for foot disease, together with practical approaches to assessment of the high-risk foot, is essential for safe and effective service delivery. Normal function of the lower limb is dependent on viability of a wide range of tissues. Optimum function requires that skin, bone, muscle, nerve, vessels and connective tissues are structurally sound. Loss of viability results in reduction of normal function, eventual total loss of function or systemic complications. Maintenance of tissue viability enables functional ability, keeping the patient mobile and independent and maintaining quality of life. For the lower limb practitioner, skin is the most common tissue to lose viability, resulting in potentially serious consequences for the patient. Key functions of the skin are given in Table 17.1.
THE AT-RISK FOOT The term 'at-risk foot' is used to describe a foot which is at risk of loss of tissue viability. Usually, 427
428
SPECIFIC CLIENT GROUPS
Table 17.1
Functions of the skin
• Prevents dehydration • Contains other tissue of the body Communication • Sensation (touch, heat, cold, pain, etc.) • Immunological (direct barrier, cellular) Protects body from ultraviolet light • Thermoregulation Shock absorption Vitamin 0 production • Protection from irritants (chemicals, etc.)
the increased risk relates to intrinsic factors which reduce the ability of the soft tissues to withstand normal minor environmental stresses (extrinsic factors). Therefore, an at-risk foot may be seen to be one where soft tissues are more vulnerable to the effects of environmental stresses. Additionally, an at-risk foot is one which is often less likely to recover quickly from minor stresses and minor wounds than the normal foot. Often recovery is likely to be complicated, delayed or incomplete. In severe cases, recovery is not possible and stasis, spread or deterioration of the condition occurs. The role of the practitioner is often to first identify factors which may place a patient's lower limb status at high risk. Some factors which may be responsible for an at-risk foot are given in Table 17.2. It is important to bear in mind that in many cases most at-risk feet are victims of more than one causal factor. Many at-risk feet have a complicated series of factors responsible for causing disease risk. A good example of this is the diabetic foot ulcer. Diabetic foot ulcers are either neuropathic, ischaemic or a combination of both factors. Additionally, the patient may be immunocompromised, have a coexisting infection or be suffering abnormal weightbearing traumas on already damaged tissues. It is important for the practitioner to identify and eliminate all risk factors if such an ulcer is to be given the best chance of healing. From the clinical perspective, an at-risk foot is one which is more likely to develop significant pathologies such as:
Table 17.2
Factors responsible for an at-risk foot
Classification
Conditions
Vascular - ischaemia
Peripheral vascular disease Critical limb ischaemia Occlusion (e.g. tourniquet) Severe anaemia Deep vein thrombosis Compartment syndrome Buerger's disease Microangiopathy
Vascular - venous stasis
Incompetent lower limb valves Congestive heart failure (right-sided) Obesity Failure of respiratory/ abdominal pump Calf muscle pump failure Pericapillary fibrin deposition Oedema - pitting/non-pitting
Neurological
Distal symmetrical polyneuropathy Mononeuropathies Radiculopathies Upper motor neurone lesions Lower motor neurone lesions Diabetes mellitus Tabes dorsalis Leprosy Alcoholism Vitamin B 12 deficiency HIV/ AIDS
Neoplasia
Malignant melanoma Basal cell carcinoma Squamous cell carcinoma Malignant transformation of wounds
Infections
Erysipelas Osteomyelitis Cellulitis Lymphangitis Lymphadenitis Bacteraemia Septicaemia Dermatophyte infection Yeast infection Herpes infection
Immune system dysfunction
DiGeorge syndrome HIV/AIDS Malnutrition Diabetes mellitus Long-term steroid use Immunosuppressive drugs Radiation Effects of ageing Leukaemia Lymphoma (Cont'd)
THE AT-RISK FOOT
Table 17.2
(Conf'd)
Classification
Conditions
Trauma
Heat Cold Radiation Chemicals (acids and alkalis) Mechanical (pressure, shear, friction)
Musculoskeletal
Rheumatoid arthritis Gout Osteoarth ritis Psoriatic arthropathy Reiter's syndrome Neuroarthropathy (Charcot foot) Ankylosing spondylitis
• • • • • •
ulceration infection necrosis amputation malignant lesions severe deformity.
Correct determination of risk factors is essential in order that effective preventative, curative or rehabilitative management can be planned.
TISSUE VIABILITY Factors essential for tissue viability Viable tissue is, by definition, that which is able to withstand normal environmental stresses without loss of structure or function. For tissue viability to be maintained, the following factors are essential: • Adequate oxygen supply: good quality and quantity of blood • Adequate nutrient supply: sufficient nutrients to meet the respiratory need of cells • Adequate removal of respiratory metabolites: removal of carbon dioxide, lactate, etc. • Adequate sensory, motor and autonomic nerve supply • Adequate immune function: local and systemic immune mechanisms are effective
429
• Freedom from infection: local or systemic • Freedom from major environmental stresses: heat, cold, radiation, mechanical trauma, chemical trauma • Freedom from malignant disease: skin, soft-tissue, vascular or bone malignancy • Freedom from intrinsic (systemic or local) disease • Ability to compensate for minor changes to the environment: production of melanin in response to ultraviolet radiation production of hyperkeratosis in response to mechanical trauma ability to regulate constant pH, temperature, etc.
Factors which can result in loss of tissue viability Whenever skin viability is lost, the patient may lose one or more of the normal functions of skin. For example, a large full-thickness skin wound can cause a patient to lose significant volumes of body fluids, body heat and to place the person at high risk of infection. Additionally, the affected area of skin will be unable to withstand normal weightbearing traumas and will be susceptible to damage from ultraviolet light. Any pharmacological (or other) product placed on the affected area is liable to systemic absorption. A potentially significant factor can be where patients choose to place - e.g. steroid or iodine ointments - on their wounds. This combination of risks has the potential to create significant complications, including infection, dehydration, shock, hypothermia, irradiation trauma and unintended systemic action of topical medicaments. Even small wounds can have significant consequences for some patients. Any wound provides a potential portal of entry for microorganisms. In a susceptible or immunocompromised host this may lead to serious and potentially limb- (or even life-) threatening infection. A good example of this is small open interdigital fissures, resulting in
430
SPECIFIC CLIENT GROUPS
rapidly spreading beta-haemolytic streptococcal infection (erysipelas) in immunocompromised patients. In this example, the minor structural change to the skin (i.e. the fissure) is no longer suited to the skin's function as a barrier to microorganisms. Tissue viability is therefore lost. Traumatic versus trophic wounding. Skin and soft tissue failure can be said to occur therefore when environmental stresses exceed the structural strength of the soft tissue. Major environmental stresses (e.g. burns, lacerations, incisions) are likely to exceed the strength of even normal tissues and result in traumatic wounding. However, minor environmental stresses are encountered more regularly. Minor stresses might include friction, pressure, shear, ultraviolet radiation, etc. In most cases these minor stresses will be dissipated or absorbed (attenuated) by soft tissues and result in no noticeable degeneration of the tissues. However, even minor environmental stresses such as these have the potential to result in wounding when the integrity of the soft tissues is compromised. Compromise may arise in the form of atrophic skin, ischaemia, loss of sensation or other significant changes to normal tissue structure. In such cases minor environmental stresses may result in trophic ulceration.
Classifying loss of tissue viability It is not enough to determine whether or not
there is loss of tissue viability. This will only tell us that something has gone wrong and that some action should be taken, but gives us no idea of the cause or severity of the situation and therefore no guide as to appropriate action. Much more information will be needed from the assessment process. In order to gain that information in a logical manner, it is important to use a system to classify the loss of tissue viability. The purpose of a classification system is to aid: • • • • •
diagnosis prognosis/degree of risk treatment plan monitoring research and audit.
Any system which is to be used practice on a daily basis should be:
In
clinical
• simple to use • easy to remember • validated. Some systems are designed primarily for research and audit purposes and may of necessity require complex or costly apparatus such as that to measure the transcutaneous oxygen tension (TcpOz) (Ch. 6) or a complex questionnaire. Such systems are more suited to specialist centres rather than the routine clinic. Several of the earlier systems were designed to record wounds rather than loss of tissue viability and therefore do not accommodate conditions where there is no actual loss of tissue although these can usually be adapted to do so. As pointed out in his excellent chapter in The Foot in Diabetes, Young (2000) draws the distinction between a classification system and a descriptive system. A classification system is applied at the first presentation of the patient. The loss of tissue viability will be assigned to a particular category and will remain in that category, no matter what the progression and final outcome. For example: a system based on the aetiology of the loss of tissue viability would place a blister caused by the persistent rubbing of an ill-fitting shoe on the back of the heel as a traumatic loss of tissue viability and would remain in that category throughout the treatment process to final outcome. On the other hand, a descriptive system will change with each occasion of assessment. For example, there may be blood in the fluid of the blister initially, which may disappear as the blister heals. Other descriptors could be surface area, colour, appearance of margins or presence of infection. The difficulties here are threefold: first, in deciding which factors to include among the many possibilities. Decisions should be evidence based, where the factors chosen have been shown to have a significant influence on healing, or other valid reasons for inclusion, such as an indicator of efficacy of treatment or a guide to management. Where the classification system is
THE AT-RISK FOOT
also used to indicate the degree of risk, the number of possible factors increases further, making the designing of an easy-to-use system all the harder. The second task is to obtain clear definitions of these factors. The lack of universal consensus on definitions makes comparison difficult. For example, a very simple classification system of ulcers which nonetheless is an aid to prognosis and degree of risk, is to determine whether the ulcer is superficial or deep. However, unless there are clear definitions as to exactly what is understood by these two terms, we cannot be sure that an ulcer graded as superficial by one practitioner, which subsequently deteriorates, would not have been classified as deep by another. Thirdly, an accurate but simple means is needed to measure the factors concerned, and such means are not available for all factors. For example, it is generally held that if an ulcer can be probed to bone, it is assumed that osteomyelitis is present, regardless of whether it can be detected on X-ray, but this rule has not been validated by research. Similar problems apply to the presence of ischaemia and neuropathy (Chs 6 and 7). So far, no single system has been designed which is appropriate to all situations: each has its limitations and many practitioners will use a combination of classification and description to record both details of loss of tissue viability and to estimate the degree of risk.
Aetiological classification One example of a well-validated classification system for lower limb ulcers is the aetiological system (Table 17.3). This is appropriate for use by practitioners in a clinical setting as it is a useful guide for a treatment plan, since removal or amelioration of the cause will be a fundamental step in the treatment. There is also some correlation between cause and prognosis, e.g. an uncomplicated neuropathic ulcer has a significantly better prognosis than a similar-sized ischaemic ulcer. Although used more often for the classification of ulcers, this system can be easily adapted to classify loss of tissue viability. The precise categories
431
Table 17.3 An example of an aetiological system of classification of lower limb ulcers
Category of lesion
Examples of conditions
Dermatological Endocrine Haematological
Atopic eczema Diabetes mellitus Sickle-cell anaemia, cryoglobulinaemia Stevens-Johnson syndrome Rheumatoid arthritis Tuberculosis Squamous cell carcinoma, malignant melanoma, Kaposi's sarcoma, basal cell carcinoma Hansen's disease (leprosy), diabetes mellitus, syringomyelia Burns, friction blisters, cuts, pressure sores Peripheral vascular disease, venous hypertension
Iatrogenic Immunological Infectious Neoplastic
Neurological Traumatic Vascular
can be altered according to the wishes of the practitioner. For example, vascular could be divided into arterial, venous and lymphatic categories and iatrogenic could be included as a type of traumatic cause of ulceration. It must be borne in mind that infection can complicate many lower limb ulcers, but is rarely a cause of ulceration. Nonetheless, this system has some limitations. It tells us nothing about the degree of loss of tissue viability. For this we could add a descriptive section, based on measurement of depth of the deepest part of the wound. This has been shown to have a strong correlation with prognosis and so would be helpful in determining the degree of risk of slow healing, ulceration and amputation. It is also possible that a particular lesion can be assigned to more than one category, which detracts from the precision of the system. For example, a basal cell carcinoma is a skin cancer and could be classified as both a neoplastic and a dermatological lesion and the ulcer seen in the diabetic foot could be classified as both endocrine and neurological. Meggit-Wagner wound classification system
(Table 17.4). This is another well-validated system which chiefly yields information as to the severity of the wound and therefore relates to prognosis and degree of risk. It has the further
432
SPECIFIC CLIENT GROUPS
Table 17.4
Meggitt-Wagner wound classification
Grade Appearance
2
3 4
5
Loss of tissue involves dermis only Loss exposes tendon or bone Loss exposes tendon or bone, with osteomyelitis or abscess Gangrene of digits or forefoot Extensive gangrene of the foot
Implication
}
No significant ischaemic component
}
Primarily an ischaemic problem
advantage of dividing tissue loss into that with no significant ischaemic component and that where peripheral vascular disease is a major factor and so is of help in determining the most important steps in the subsequent treatment, since wounds which are primarily ischaemic will not heal unless steps are taken to improve the blood supply. However, it has limitations, since it was designed to assess wounds and has no place for preulcerative conditions such as callus. This system has been adapted by some practitioners for the classification of loss of tissue viability by the addition of a grade a category for such conditions where no break in the epidermis has occurred. In addition, it would usually be expected that a patient with a grade 4 ulcer would have significant large-vessel disease of the lower limb and one would expect to find non-palpable pedal pulses. However, in patients with diabetes, it is quite possible for them to have digital gangrene and palpable pedal pulses, suggesting a grade 4 ulcer but with no significant major vessel pathology, the gangrene being a result of septic vasculitis or embolism. Small-vessel disease (i.e. thickening of the basement membrane) is no longer considered to be a prime cause of digital gangrene in patients with diabetes. Another limitation to this classification system is that there would be no place for the Charcot foot, even though this condition carries a high degree of risk of ulceration. A more detailed but similar classification system, which includes a grade a for intact skin and a separate
grade for spreading infection, is the Sims classification (Sims et al 1988). Almost all other systems are mainly descriptive and designed more to assess the degree of risk of ulceration/ amputation than of classifying the ulcer per se. If they are to meet the criteria for simplicity and ease of use, they inevitably focus only on aetiological and local factors, e.g. ischaemia and infection present, which gives a limited view of factors contributing to risk. San Antonio/Texas System (Armstrong, Harkless and Lavery). This group of practition-
ers designed two systems: one system is designed to classify the total range of loss of tissue viability, but has yet to be validated; the second system is concerned only with actual ulcers. The advantage of the first system is its comprehensiveness; both systems are an aid to prognosis and management. The second system has been validated and grades ulcers according to depth, presence or absence of sepsis and presence or absence of ischaemia. No reference is made to the presence or absence of neuropathy however, which is considered by some practitioners as the single most important contributory factor to diabetic ulceration. Using this system to assess the lesions of people with diabetes, Lavery et al (1996) were able to show that patients with infection and ischaemia were 90 times more likely to have an amputation than patients with lower-grade lesions, thus showing the importance of local wound conditions on outcome. S(AD) SAD system (Table 17.5). This is a comprehensive system based on the San Antonio system but with modifications and extensions (Macfarlane & [effcoate 1999). It is also aimed at patients with diabetes but is designed for research and audit rather than as a guide to management. However, it could be adapted for management purposes (Serra 2000). The key elements of this system are size of a wound, as measured by both depth and surface area, infection, ischaemia and neuropathy. Each of these elements is assigned a grade from a to 3 according to severity, with grade a representing a normal foot and grade 3 representing the worst situation. The advantages of this
THE AT-RISK FOOT
Table 17.5
The S(AD) SAD classification
Grade Area 0 1
2 3
Depth
Skin intact <10 rnrn-
Skin intact Skin and subcutaneous tissues 10-30 rnrn- Tendon, joint capsule, periosteum Bone and/or joint >30 rnm'' spaces
Sepsis
Arteriopathy
Denervation
No infection Superficial: slough or exudates Cellulitis
Pedal pulses palpable Diminution of both pulses or absence of one Absence of both pedal pulses Gangrene
PinpricklVPT sensation normal Reduced or absent pinprick sensation. VPT raised Neuropathy dominant: palpable pedal pulses Charcot foot
Osteomyelitis
system are that it covers the whole range of loss of tissue viability and includes the Charcot foot. However, the authors suggest testing either rather than both small and large nerve fibres for neuropathy which could lead to a false-negative result since denervation of each type of nerve fibre does not necessarily progress at the same rate. The measurement of the vibratory perception threshold requires the availability of a neurothesiometer for the latter, which may not be readily available in a routine clinic, but the authors do suggest the cheaper alternative method of using a 10 g monofilament. The authors acknowledge that measurement of neuropathy is an imperfect science. The system awaits full evaluation but there is a report of its successful use in a large multidisciplinary clinic in Portugal. Edmonds and Foster system. This system is designed specifically to aid management of diabetic foot lesions by assigning the foot to a stage of graded severity, according to the criteria shown in Table 17.6, and dividing the lesions into one of two aetiological categories (neuropathic or neuroischaemic), as management differs for
Table 17.6
Staging the diabetic foot
Stage
Clinical status
2 3 4 5 6
433
Normal. No presence of callus, ischaemia, neuropathy, deformity, swelling High risk. One or more of the above is present Skin breakdown or presence of blister, splits or grazes for more than 1 week Ulcer and cellulitis Necrosis Advanced necrosis, foot cannot be saved
these two categories. Edmonds & Forster (2000) acknowledge that their system of staging does not accommodate the Charcot foot and that the system would need extending for research and audit purposes.
APPROACHES TO DETERMINING DEGREE OF RISK Holistic overview To fully determine the degree of risk for any patient, one would need to take into account all factors which can influence healing, including not only the local condition of the lesion but also the patient and his environment. Although few of these latter factors are included in any proposed classification system, because such inclusion would make the system very cumbersome, much of the data will be recorded as part of a primary patient assessment (Ch. 5) and will be taken into account by the practitioner when assessing the degree of risk. Most work has been carried out on people with diabetes, as these people form the group with highest risk of worst-scenario lower limb complications of ulceration and non-traumatic amputation: 40-70% of all non-traumatic lower limb amputations are related to diabetes mellitus and 85% of all such amputations are preceded by a foot ulcer (International Working Group on the Diabetic Foot 1999). Psychological factors
Recent research has started to focus on patients' own perceptions of their health and their degree
434
SPECIFIC CLIENT GROUPS
of risk. There is a strong association between non-compliance with therapy and amputation in a number of studies on patients with diabetes. The patient with diabetic neuropathy who has been told emphatically of the importance of checking his footwear and of the consequences of failure to heed this advice, but who returns later with an ulcer due to a foreign object in the shoe, possibly believes himself to be invulnerable: it won't happen to me. Education is seen as a vital part of the management of such patients, but simple transfer of knowledge is not enough. The patient's perception of his health status and the desire to alter behaviour are important influencing factors. Complex interactions of psychological factors in people with at-risk feet can result in denial or detachment syndromes. In these cases patients perceive their foot health of low importance or relevance, often psychologically detaching themselves from their foot problems. These situations can be a particular challenge for practitioners to manage and call for a multiprofessional approach to assessment and management. Other behavioural factors can be detrimental to health in general, such as tobacco smoking and excessive alcohol drinking, as well as having particular negative effects on healing outcomes.
Environmental factors
Reduced access to health care is also associated with increased risk. No matter how well motivated a patient may be, if there are inadequate footcare facilities, or those facilities are out of reach due to lack of transport, then there is always the possibility that a lesion will develop or worsen before adequate help is received. Other environmental factors such as inadequate heating in the home or poor hygiene are closely related to socioeconomic factors and lack of education, as discussed in the previous section. Occupational factors
Apart from the earnings-related factor, certain occupations independently place the person at a higher risk of lower limb complications. For example, people who have sedentary jobs are at higher risk of obesity, heart disease and venous stasis problems than people in more active jobs. People such as top executives who spend long hours in flight are also at high risk of deep vein thrombosis. Occupations involving exposure to the elements will increase that person's chance of developing cold-related conditions such as chilblains, which can lead to ulceration.
Socioeconomic factors
Previous medical history
Low economic status has been shown to be associated with a higher risk of amputation. A person on a low income is less likely to be able to afford good footwear, adequate heating in the home, a balanced diet, etc. The socioeconomic status of an individual is more important than whether the person belongs to an ethnic minority group. Support in the form of family and friends and religious or social groups is important in reducing the risk, especially so in patients who suffer visual or other impairments, and this could be one reason why ethnic minorities are not at a disadvantage in terms of risk of lower limb ulceration and amputation. Lack of education in general is also an influencing factor: e.g. this may lead to inability to understand footcare advice or to realise the importance of adequate diet.
Past medical history is important, since previous ulceration or amputation will place the person in a high-risk category for further ulceration and amputation. This is because the factors that contributed to the development of the first ulcer are likely to still be present and, once amputation has been performed, the extra stress on the already compromised contralateral limb will place that limb at high risk. Age
The individual's healing ability will vary from person to person across any age band but in general healing slows with age. A more significant factor is the presence of coexistent disease, the likelihood of which increases with age.
THE AT-RISK FOOT
435
Coexistent disease
Surface area of wound
All too often a practitioner will be confronted with a non-healing ulcer: this, despite the fact that extreme care, the most appropriate dressings, antibiosis and careful observation and monitoring have all been carried out. In many such cases there is an underlying systemic condition which is delaying healing. There are many conditions which can delay healing and will therefore place the person in a higher risk category, some examples of which are shown in Table 17.7. In addition, the treatment itself for coexisting conditions may also impair healing. A thorough primary patient assessment, as described in Chapters 5-10, should detect relevant underlying conditions/treatment.
The surface area of the wound is an important piece of data, since it enables the practitioner to chart the progress of a lesion and thus determine the success or otherwise of treatment. Evidence of surface area as a prognosis for healing is contradictory, with a meta-analysis of wound healing studies by Margolis et al (2000) on diabetic neuropathic foot ulcers showing no correlation, whereas a recent paper by Oyibo et al (2001) looked at 194 patients with diabetic foot ulcers and found ulcer area at presentation was greater in the amputation group compared with healed ulcers, so the authors conclude that ulcer area does predict outcome and should be included in a wound classification system. The same authors found that the patient's age, sex, duration/type of diabetes, and ulcer site had no effect on outcome. Methods of measuring surface area vary from the very simple to the very complicated. The simplest method is to use a sterile, disposable millimetre ruler and record the longest axis of the wound as the length, L, and the width, W, as the longest dimension perpendicular to L. One of two formulae can then be used to calculate the surface area: A = L x Wx 0.785 or A = L x W x 0.763
Local indicators Having assessed the patient holistically for risk factors, it is necessary to turn our attention to the area of tissue viability loss itself and make an accurate recording of lesion details. This will often be carried out as part of the routine assessment of skin and the appendages in the clinic (Ch. 9). Some of the systems used have been discussed earlier in this chapter. Methods of obtaining descriptive details will now be discussed.
Table 17.7
Examples of conditions or treatments which may delay healing
Category
Examples
Cardiovascular Endocrine/metabolic Immunological
Peripheral vascular disease, venous insufficiency, lymphatic obstruction Diabetes mellitus, malnutrition, deficiency syndromes, obesity DiGeorge syndrome, hypogammaglobulinaemia, human immunodeficiency virus, rheumatoid arthritis, hypersensitivity Long-term steroids, immunosuppressive drugs, radiation, cytotoxic drugs Cytomegalovirus, infectious mononucleosis, severe bacterial, mycobacterial or fungal disease Leukaemia, anaemias, haemophilia, sickle-cell anaemia Deformities, hypermobility Carcinomas, lymphomas, sarcomas Chronic obstructive airways disease Chronic nephropathy Burns, foreign bodies, repeated minor trauma, tight clothing (tourniquet effect) Inappropriate dressings, antiseptics, environmental conditions, caustics and irritants
Immunosuppressive agents Infectious Haematological Musculoskeletal Neoplasia Respiratory Renal Traumatic Exogenous factors
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SPECIFIC CLIENT GROUPS
For derivations of these calculations, see Schubert (1997). A second method requiring only simple apparatus is to place a sterile, flexible, transparent grid over the wound: the grid has a removable backing and is marked into J-cm squares. The margins of the lesion can then be traced on to the grid and the surface area calculated by counting the squares. Disposal of the removable backing prevents crossinfection, and the tracing can be stored in the patient's notes for future reference. There are various strategies for calculation of surface area, such as including all whole squares and all partial squares on the right, discarding all partial squares on the left, etc., or using a formula such as: A c =Nc A c-r = (N c + (0.4 x N p ) )
where A c is the surface area of whole squares, A c-r is the surface area of whole and partial squares, N c is the number of complete squares and N p is the number of partial squares within the traced area. If the grid is divided into smaller squares, such as 0.5 cm x 0.5 em then each formula has to be multiplied by 0.25 to obtain the area in em(Richard et aI2000). Both of these methods have the advantage of being quick, simple to use and inexpensive. The disadvantages are that it is more difficult to obtain an accurate tracing if the lesion is on a curved surface such as the heel and that these methods are very subjective. A more objective measurement is made by using a camera to take a photograph of the lesion. The camera must always be placed at a set distance from the lesion and a scaled ruler should be positioned at the top or bottom of the lesion, in the same vertical plane. The area of the lesion can then be calculated from the developed photograph. The advantages are that the measurement will be more objective and there is no risk of cross-infection, but disadvantages are that errors will again be present if the wound is on a curved surface, the equipment is much more expensive than use of a transparent grid and the result is not instantly available unless a Polaroid camera is used.
A further development is to use a digital camera and associated software, which will enable the image to be displayed on a computer screen. The operator can click on to various points around the margin of the lesion and the software will instantly calculate the surface area. The advantages are increased accuracy and instantaneous results. The disadvantages are the initial expense of the equipment and the need to develop a skill in operating the equipment. A group of workers from France have developed a planimetry software program, which uses the tracing of the wound on a transparent grid together with the computer mouse acting as a digitiser, to transfer the tracing to the computer, whereupon the software automatically calculates the surface area. This method was compared with calculating the surface area by length and width, by square counting and by using image-processing software and was found to be highly reproducible and accurate. The advantage of this method is that it does not require the expense of a digital camera, but on the downside it is more time-consuming (Rajbhandari et aII999). Depth of wound The depth of the wound is an important piece of data, since as mentioned earlier, depth shows strong correlation with prognosis and degree of risk. The usual method is to use a blunt, sterile probe and measure the depth at the deepest part of the wound. The advantages are ease of use and low cost. The disadvantages are risk of crossinfection and deciding exactly where the deepest part of the lesion lies. It is also difficult to measure the depth of very narrow lesions such as fissures or splits in the epidermis. Lesions of unbroken skin will of course have zero depth. Volume of wound Although some research is being undertaken using stereoscopic equipment, no very satisfactory method of measuring the volume of a wound has been developed. Other methods tried have included injecting normal saline and mea-
THE AT-RISK FOOT
suring the volume used to fill the wound - but this assumes the wound to have no pre-existing fluid present - or using some other medium to fill the cavity, such as an inert foam or a hydrogel. None of these methods work very satisfactorily and there is no great advantage in measuring volume rather than depth. Colour of wound
The colour of the wound can either be a mere recording of colour by name, referring to either the base of the wound or the surrounding epidermis, or using some sort of standard colour chart. Successful use has been made of ordinary household paint colour charts for this purpose, which have the advantage of reducing observer bias and making it easier to compare the lesion at a later date. Colour has some bearing on prognosis, since a red base will suggest good granulation tissue and better prognosis for healing than a grey base, which suggests poor blood supply, or a yellow base, which suggests presence of infection. Margins of wound
Margins of wounds can also be related to prognosis. A 'saucer-shaped' wound suggests healing is under way, whereas undermined edges suggest the presence of a sinus, straight edges suggest no
Table 17.8
437
change and rolled edges may indicate malignant change. Infection
Infection is one of the most important indicators for risk (Carlson 1999). Table 17.8 lists useful indicators of foot infection. The exudate can further be described in terms of colour and consistency, which gives some indication of the pathogens involved. A more precise way of determining which pathogens are present is to take a swab (Ch. 13). The usual method is to swab deep in the wound before any lavage of the wound has taken place. However, controversy rages concerning the detection of infection, since it is recognised that any swab taken of a wound will show the presence of pathogens, but whether these are merely commensals or true pathogens is more difficult to decide. It is recommended by some that tissue scrapings are collected from the base of the wound using the blunt edge of a scalpel blade and that the blade and adherent tissue be sent to the pathological laboratory for analysis. A similar controversy surrounds the detection of osteomyelitis, since X-rays are not reliable in the early stages and clinical signs such as a 'sausage' toe and failure to heal are often the only indicators. Probing to bone is used by many as a rule of thumb but this
'PREPSOCS' indicators of foot infection
Pain Redness
Exudation
Pyrexia
Slow healing Oedema Colour change (blue, grey, black) Smell
Not necessarily present (especially with sensory neuropathy). Throbbing, pulsatile or persistent pain. May also have generalised malaise Soft tissue infection produces a diffuse area of cellulitis radiating from a central point (often a portal of entry). May spread via lymph vessels, presenting as clear red lines (lymphangitis). May herald onset of systemic spread Amount of exudate produced is proportional to blood supply to wound. Consistency and colour altered by microorganisms (e.g. creamy-yellow pus indicates staphylococcal infection, green pus indicates pseudomonas infection) Local rise in temperature may be present. Need to distinguish from other causes of temperature increase (e.g. Charcot foot). Rise in systemic temperature is common in severe infection, or indicates systemic involvement If wound is slow to heal or failing to heal, suspect underlying infection Acute inflammatory response associated with infection produces local oedema. Oedema may impede normal function (e.g. reduce range of motion of a joint) Change in colour usually indicates presence of infection and/or tissue necrosis Malodour indicates presence of microorganisms, e.g. presence of anaerobes
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is not entirely accurate as a study by Armstrong et al (1998) showed using bone biopsies to confirm infection. Pain
The presence or degree of pain does not always bear relation to the severity of a lesion since, in conditions such as diabetes mellitus, peripheral sensory neuropathy may mean that the foot is insensate and the patient feels no pain at the site of a lesion. Indeed, the first time such a patient may realise he has a problem is on noticing hosiery or footwear being soaked in exudate, or on routine visit for a foot inspection at the clinic, or by the observation of a relative or friend. However, practitioners usually record the presence and nature of any pain experienced by the patient, since alleviation of the pain is one of the therapeutic objectives and, whereas absence of pain does not necessarily indicate all is well, presence of pain is usually a strong indication of an underlying problem. Pain is often recorded using the patient's own description of the pain. A more objective method is to use the visual analogue scale (VAS) to show intensity of pain, with one end of the line indicating no pain and the other end indicating worst pain ever (Ch. 3). The patient is asked to mark a point on the line corresponding to the intensity of pain felt at that moment. A second often-used method is the McGill Pain Questionnaire (MPQ), or a modification of it, which consists of the patient selecting adjectives from various groups to show the nature and intensity of pain. Both methods are useful in monitoring pain and pain relief, but pain is a very difficult entity to compare from one patient to another. The VAS is more suited for use in a busy clinical practice than the MPQ, which takes time to complete, but yields more information and is more suited for research purposes.
Systems approach to risk assessment As can be seen from Table 17.2, pathological changes within the body systems can threaten
tissue viability. Each physiological system will now be considered in turn and attention drawn to changes from the norm which increases the 'atrisk' status of the patient. Details of actual assessment procedures will not be included, as these can be found in the relevant chapters of this textbook. Cardiovascular system
Tissue viability is compromised whenever local circulation is compromised. An inefficient drainage system can be as threatening as a reduced blood supply as both can produce local ischaemia, leading to reduced diffusion of nutrients and gases with subsequent reduction in tissue metabolism. The cause may be local factors such as a local vasculitis caused by local infection or vasospasm as seen in chilblains or Raynaud's phenomenon, a stenotic artery due to atherosclerosis or stasis following incompetent veins or a damaged lymphatic system; 85% of lower limb ulcers are venous ulcers and they are often very resistant to healing. Chapter 6 discusses causes and signs and symptoms of venous stasis in more detail. Systemic factors such as congestive heart failure or severe anaemia can lead to ischaemia in the lower limb and external factors such as tight footwear, hosiery or dressings can also be a cause of localised ischaemia. Vasospastic disorders such as Raynaud's disease or phenomenon, acrocyanosis, erythrocyanosis and chilblains (perniosis) can result in loss of tissue viability; prolonged vasospasm is triggered by exposure to a cold environment or to sudden changes in temperature. Thromboangiitis obliterans (Buerger's disease) is a small-vessel disease affecting smokers. This mainly affects young men, and causes small areas of necrosis on the tips of the fingers, toes, nose and ears. The cardinal signs of a compromised circulation are absence of pedal pulses, an ankle/brachial pressure index below 0.9, ischaemic pain on exercise or at rest and oedema (Ch. 6). Sudden temperature change or a difference in temperature between the two lower limbs is also an important sign. Colour changes and absence of hairs are not
THE AT-RISK FOOT
sufficient signs on their own, but help to build the whole picture of a limb or foot with a compromised circulation. The absence of one pedal pulse in a foot indicates a compromised circulation but if the other pedal pulse is intact, significant ischaemia is unlikely. Although calcification may lead to a false high value for the ankle/brachial index, a low value always indicates some reduction in blood flow: the lower the index, the higher the risk. Digital pressures can also be measured using an appropriate pressure cuff. Further evidence can be obtained by observing or listening to the waveform or flow sounds of major arteries and veins using a hand-held Doppler or measuring the transcutaneous oxygen diffusion pressure (Tcp02) on the dorsum of the foot or at digital level. Values below 50 mmHg on the leg or dorsum of the foot indicate some degree of ischaemia.
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Table 17.9 Examples of conditions affecting the skin which increase the at-risk status of the patient
Symptom
Condition
Dry fissures
Sun, wind, ageing, hypothyroidism, chemotherapy
Wet fissures
Occlusive dressings and footwear, poor hygiene, hyperhydrosis, certain occupations, e.g. baker, cook
Callus and corns
Foot deformities, abnormal foot function, ill-fitting footwear, ichthyosis
Blisters
Epidermolysis bullosa, pompholyx, pemphigus, urticaria, pustular psoriasis, juvenile plantar dermatitis, ill-fitting footwear
Pruritic lesions
Tinea pedis, atopic eczema, venous stasis eczema, contact dermatitis, asteatotic dermatitis
Malignant lesions
Melanoma, squamous cell carcinoma, basal cell carcinoma, Kaposi's sarcoma
Trauma
Cuts, bruises, ingrown toenail, insect bites
Dermatological system
Infection
Paronychia, onychia, erysipelas, necrotising fasciitis
As explained in Chapter 9, the intact skin is an important barrier to pathogens and any break or potential break in that integrity, such as cuts and bruises, poses a risk of infection. If infection is already present, as in paronychia or onychia, then there is risk of the situation worsening with development of cellulitis and lymphangitis. Any condition which produces a localised change, resulting in the altered ability of the epidermis and dermis to withstand normal daily trauma such as an excessively moist or dry skin - poses a threat to the integrity of the skin (Plates 29 and 30). Examples of such conditions can be seen in Table 17.9. Alteration in the hydration of the stratum corneum, such as is seen in the dry skin of people exposed to wind and sun, due to ageing, certain drugs such as those used in chemotherapy, or a systemic condition such as hypothyroidism, all render the epidermis more likely to form fissures and thus portals of entry to pathogens. Similarly, excessive hydration as seen in the macerated skin due to occlusive dressings, prolonged immersion in water or poor attention to personal hygiene can lead to moist fissures. Blisters, including vesicles and bullae, whether caused by external
trauma such as friction from footwear or due to a systemic condition such as bullous pemphigoid, as well as callus and corns produced at sites of increased mechanical stress, can all ulcerate, exposing the patient to risk of infection. Often the first sign of increased trauma is a slight reddening of the skin at the sites of increased stress, such as on the dorsum or apices of toes from illfitting footwear. This is the initial inflammatory response to trauma and should never be disregarded. If the lesion is pruritic, such as in atopic or venous eczema, or in tinea pedis, then the chances of infection from scratching are even higher. In addition, ulcers and other skin lesions such as pigmented naevi, may undergo malignant change, which is obviously a threat not just to the affected limb but to the whole person. Any patient with a lesion which shows rapid change in colour, size or wound margins or which exhibits bleeding or other discharge should be immediately referred for further investigation such as biopsy and pathological examination.
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Malignant naevi can arise under the nail as well as on skin and not all malignant naevi arise from pre-existing pigmented naevi. In addition, not all melanomas are pigmented. Endocrinological system
Metabolic and endocrine disorders can cause widespread effects of morbidity and even mortality and need to be noted when taking the patient's medical history, but their effects on the at-risk status of the lower limb vary from none to extremely marked consequences, as can be seen from Table 17.10. In addition to direct effects on the lower limb, many endocrine and metabolic disorders produce other symptoms which may place the person at risk of lower limb complications: for example,
Table 17.10
ocular muscle weakness, as sometimes seen in Graves' disease, may lead to blurred and double vision, and retinopathy associated with diabetes mellitus indirectly places the person at a higher risk of lower limb problems, because of reduced ability to notice any problem or to carry out routine nail care safely. Certain endocrine disorders can place the patient at risk when undergoing surgery and require appropriate prophylaxis, extreme vigilance and prompt treatment if an emergency arises. A thorough assessment is essential to ensure awareness of such conditions. Hyperthyroidism can sometimes lead to a lifethreatening situation, thyrotoxic storm, where the patient may present with cardiovascular collapse and shock. The practitioner must be aware that infection, surgery, trauma, fright, diabetic
Endocrine and metabolic disorders with effects on the lower limb
Endocrine/metabolic disorder
Effects on the lower limb
Acromegaly/gigantism (excess pituitary growth hormone)
Enlargement of feet; erosion of articular surfaces leading to joint problems; thickened, sweaty skin
Addison's disease (adrenocortical plus insufficiency)
Increased pigmentation over bony prominences and extensor surfaces, generalised effects of dehydration, weight loss, weakness, fatigue, orthostatic hypotension
Muscle wasting and weakness; thin, atrophic skin; poor wound healing; Cushing's syndrome (excess cortisol); may be due to excess pituitary ACTH (Cushing's disease) reduced inflammatory response; tendency to bruising; osteoporosis; plus generalised effects of hypertension and glucose intolerance or exogenous ACTH or steroids Diabetes mellitus (a relative or absolute lack of insulin secretion, leading to elevated blood glucose levels and alterations in lipid metabolism)
Arteriosclerosis, leading to calcification and atherosclerosis of arteries Peripheral vascular disease is 50-100x more common in patients with diabetes Neuropathy can appear in various forms. The most common form is bilateral, symmetrical, peripheral sensorimotor polyneuropathy, but wasting of hip and thigh muscles (diabetic amyotrophy) predominantly affects elderly males and single nerves can also be affected
Hypocalcaemia (most common causes are deficiency of parathyroid hormone, vitamin D or kidney disease)
Tetany (paraesthesia of lips, tongue, fingers, feet, muscle spasm). Lack of vitamin D will lead to reduced calcium absorption in the gut, compensated for by parathyroid hypersecretion, leading to bone resorption, rickets or osteomalacia, with a tendency for bowed legs and fractures
Hypercalcaemia (idiopathic hypersecretion of parathyroid hormone)
Muscle weakness, bone resorption of phalanges and soft tissue calcification, osteitis fibrosa cystica (rare)
Hyperthyroidism (the most common form is an autoimmune condition called Graves' disease, but other forms also exist)
Moist, warm skin, pretibial myxoedema (infiltrative dermopathy), muscle weakness, wasting
Hypothyroidism (the most common form is an autoimmune disease called Hashimoto's disease)
Dry, scaly, coarse, thickened skin; a tendency to tarsal tunnel syndrome
Postmenopausal syndrome (fall in oestrogens leads to bone resorption)
Osteoporosis, leading to crush fractures of spine, and fractures of wrist (Colles' fracture) and of neck of femur (Perthes' fracture)
THE AT-RISK FOOT
acidosis or discontinuation of antithyroid medication can all precipitate a thyrotoxic storm, which is a medical emergency requiring immediate hospitalisation. A patient who is receiving or who has received long-term steroids in the previous year, such as a person with rheumatoid arthritis, will show a reduced inflammatory response, poor healing ability and increased risk of infection and at times of injury or surgery is at risk of cardiovascular shock due to a sudden fall in blood pressure. The endocrinological condition which has extremely important consequences is diabetes mellitus. Whatever the cause, be it an autoimmune disease causing type 1 diabetes or a multifactorial response to obesity, genetic input and a host of other factors, producing type 2 diabetes, the consequences on the lower limb are equally serious. The major consequences are an increased risk of peripheral vascular disease and a high risk of peripheral neuropathy. In patients with diabetes, the single most important risk factor for ulceration is the presence of peripheral neuropathy and the most important contribution to delayed healing is ischaemia. Thus, a thorough assessment of both the cardiovascular and the neurological systems are essential for patients with diabetes (Chs 6 and 7). There are several forms of neuropathy that may affect the person with diabetes, but the most common is peripheral polyneuropathy, which can affect all branches of the peripheral nervous system, i.e. sensory, motor and autonomic nerves. Sensory neuropathy leads to lack of awareness of injury and a reduction in the protective function of proprioceptive reflexes. Motor neuropathy leads to wasting of intrinsic foot muscles and eventual foot deformities such as claw toes and a pes cavoid-type foot (Plate 31). This in turn leads to increased pressure on metatarsal heads, apices of digits and the heels, with formation of callus and, if no preventative measures are taken, to tissue breakdown and ulceration (Plate 32). Autonomic neuropathy leads to dry skin, with increased callus formation and loss of the normal sympa-
441
thetic reflex which adjusts vasomotor tone, so that blood flow to the foot is increased. The foot will appear warm with bounding pedal pulses (Case history 17.1). However, because of the lack of vasomotor tone, appropriate vasoconstriction as a postural reflex is missing, leading to orthostatic hypotension and arteriovenous shunting, depriving skin and superficial tissues of an adequate blood supply. This shunting also leads to the characteristic sign of engorged dorsal veins. Although the patient may lose the ability to detect a painful stimulus, when single nerves are affected the common symptom is a severe, lancinating pain, often following the distribution of a single dermatome. This gives rise to the phenomenon of the sensitive, insensate foot. Neuropathy is also a factor in the development of the Charcot foot, where absence of pain and other protective reflexes plus abnormal blood flow to bone leading to osteopenia, result in gross neuroarthropathy developing from a seemingly trivial injury or even the repetitive trauma of walking. The first signs of such a process are usually a marked increase in the temperature of one foot, with swelling, but with no apparent cause such as infection. Any
Case history 17.1 Mr Brown, a 35-year-old Caucasian male, with type 1 diabetes present for 14 years, attended the podiatry clinic for treatment of neuropathic ulcers. He weighed 15 stone and wore trainers bought in a high street store. Mr Brown had recently completed a short prison sentence where the ulcers had developed. He had a deep, heavily exuding ulcer under the first metatarsal head right foot, surrounded by callus and a shallow ulcer on the plantar surface of the left heel. A full assessment revealed the presence of bounding pedal pulses, dry, warm skin, insensitivity to a 10 g monofilament as far as the knees and inability to distinguish between warm and cold or sharp and blunt stimuli in both limbs. Some wasting of intrinsic foot muscles was observed, with slight clawing of toes and prominent metatarsal heads and heels. Diagnosis: diabetic neuropathic ulcers. The risk factors contributing to the ulcerations were deemed to be peripheral neuropathy, excessive body weight acting on bony prominences and failure to remove callus build-up.
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temperature difference of 2°C or more between the two feet of a patient with diabetes should be immediately investigated to rule out infection or acute neuroarthropathy. If early detection is missed and the foot goes on to develop a chronic Charcot foot, it will be at high risk of ulceration, due to the abnormal pressure points created by the deformity (Plate 33). Diabetes is an important risk factor for atherosclerosis and peripheral vascular disease. The pathology is identical to that in non-diabetic patients, but gender difference is lost so that females are equally at risk at all ages. The hyperglycaemia and dyslipidaemia associated with diabetes appears to upset the delicate balance of endothelial events that maintains the integrity and patency of the large and medium vessels, tipping them over towards atheroma formation sooner than in non-diabetic patients. Atherosclerosis also develops more distally in people with diabetes, with tibial vessels frequently affected and focal stenotic lesions being more common. In addition, development of collateral circulation is impaired, so that proximal lesions will have a more profound effect on distal regions than in non-diabetic patients. Early calcification of the tunica media of arteries is also seen. This is a separate process from the calcification process of Monckebergs sclerosis, which develops with ageing in medium and small muscular arteries independently from atherosclerosis and is clinically insignificant as it does not interfere with blood flow (Cotran et al 1994). Pedal vessels are rarely affected by either atherosclerosis or calcification, an important point to bear in mind when deciding on appropriate tests for measuring the degree of ischaemia in the foot. H was commonly believed that a similar pathology affected small vessels, giving rise to the term diabetic microangiopathy, and being put forward as the cause of isolated events of digital gangrene in the presence of palpable pedal pulses. However, no evidence exists for such a pathology and although functional abnormalities of small vessels do exist, the only demonstrable pathology is that of thickening of the basement membrane. Such events are no
longer thought to be responsible for necrosis in the absence of large-vessel disease and are no longer considered an impediment to the successful outcome of vascular reconstruction. If ischaemia is present and remains uncorrected, loss of tissue viability is inevitable. This alone is unlikely to lead directly to tissue breakdown, but will almost certainly do so in the presence of other factors, such as ill-fitting footwear, tight hosiery, etc. Similarly, uncorrected ischaemia will delay or prevent healing of any ulcer. Thus, if ischaemia is present, part of the management must be to improve blood supply if at all possible. Ischaemic ulcers, whether associated with diabetes or not, have characteristic features which distinguish them from neuropathic and venous ulcers, as shown in Table 17.11 (Plates 34 and 35) (Mason et al 1999). It is considered that at least 35% of all diabetic patients will have asymptomatic neuropathy (Edmonds & Foster 2000). Various studies into the aetiology of diabetic ulcers have shown that over half will be neuropathic and a very small number will be ischaemic, the remainder having both neuropathy and ischaemia. Bearing in mind the role of neuropathy and ischaemia in the prevention and healing of ulcers, most practitioners assign their patients with diabetic ulcers into either a neuropathic group or a neuro-ischaemic group and treat accordingly. Careful cardiovascular and neurological assessment of the lower limb is therefore essential. The foot that is at highest risk will be the insensate, pulseless foot and a common cause of ulceration is poorly fitting footwear (Fig. 17.1) (Case history 17.2). Often such a patient will be wearing shoes that are one or more sizes too small, to avoid the sensation that the shoe is slipping off the foot. This of course further compromises the poor circulation, and the tissues with an already reduced tissue viability will be unable to withstand the increased ischaemia, resulting in breakdown. Thorough footwear assessment (Ch, 10) is therefore also essential. Diabetes also increases the susceptibility of the patient to a wide range of infections, both bacterial and fungal, probably with hypergly-
THE AT-RISK FOOT
Table 17.11
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Characteristic features of ischaemic, neuropathic and venous ulcers
Ischaemic ulcers
Neuropathic ulcers
Venous ulcers
Usually very painful, pain alleviated by limb dependency
Often painless
Associated with an aching or bursting pain, alleviated by limb elevation
Small, shallow, punched-out appearance
Often very deep
Shallow, spreading, with irregular borders
Dry or small amount of exudate
Often copious exudate, may be bloody
Copious, often smelly exudate
Pale, grey or yellow base
Red or yellow (infected) base
Red or yellow (infected) base
On dorsum or apices of toes, under nails, borders of feet (see Plate 2)
Under metatarsal heads, apices of clawed toes, heels
Distal third of leg (see Plate 8)
Thin surrounding skin, often a halo of erythema
Thick border of callus surround
Often associated with skin scoriation or eczema, telangiectases and haemosiderosis. Varicose veins may be visible (see Plate 6)
caemia, impaired leucocytic function and poor blood supply all playing a role. As mentioned earlier, infection is rarely a cause of ulceration, but once a portal of entry is created, infection is very likely. The practitioner must be alert to any signs of infection, e.g. swelling, pain, redness, warmth, pus and any signs that the infection is spreading, e.g. cellulitis, lymphangitis. The practitioner needs to be aware of the possibility of spread of infection to bone (osteomyelitis) which is not initially detectable on xray, especially in the neuropathic foot. Severe infection in both types of foot can lead to the blue-black discoloration of necrosis (wet gangrene). Where ischaemia is a prominent feature, necrosis can occur in the absence of infection,
Figure 17.1
Ischaemic foot after dancing shoes.
due to an inadequate oxygen supply to the tissues, i.e. dry gangrene (see Plate 3). The hyperglycaemia of diabetes also affects soft tissue such as tendons, leading to a restricted range of motion at joints (cheiroarthropathy) and Dupuytren's contracture, both of which are associated with an increased risk of foot ulceration.
Case history 17.2 Mrs Shaw, a 55-year-old Caucasian female, with type 2 diabetes diagnosed 12 years ago, presented to the podiatry clinic with a very painful ulcer over the dorsolateral aspect of her right fifth toe (Fig. 17.1). She was an enthusiastic ballroom dancer and had been taking part in a contest the previous evening, for which she had worn a pair of new dancing shoes. A full primary assessment revealed a small ulcer with no surrounding callus. There was little exudate present, but there was erythema surrounding the area. No pedal pulses were palpable on the right foot. A Doppler tracing revealed dampened waveform of both dorsalis pedis and tibialis posterior. Anklelbrachial pressure index for DP was 0.7 and for TP was 0.65. Tcp02 measurement of the dorsum of the right foot was 40 mmHg. The patient was able to detect sharp and blunt stimuli on some toes but unable to detect a 10 g monofilament or the vibrations of a 128 Hz tuning, fork as far as the ankles. Diagnosis: neuroischaemic ulcer. The main risk factors were ischaemia, neuropathy and trauma from ill-fitling shoes.
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SPECIFIC CLIENT GROUPS
There are also certain occasions when the patient with diabetes is at increased risk, even though his physical condition remains unchanged, such as when on holiday abroad, particularly in hot countries, when the danger of burns from hot sand or blisters from plastic beach shoes are high possibilities. Thus, in a patient with a diabetic ulcer that is failing to heal, an holistic re-assessment is needed, to discover any contributory risk factor which may have been overlooked, such as noncompliance with prescribed treatment/advice, ill-fitting footwear, poor blood glucose control, occult infection, peripheral vascular disease or neuropathy.
Haematological system Mention has already been made of the general effects of anaemias on the lower limb in reducing available oxygen to the tissues. However, certain haematological conditions have a more direct effect on the tissue viability of the lower limb (Table 17.12). Patients with sickle cell anaemia (homozygous condition) or sickle cell trait (heterozygous condition) are at increased risk of thrombotic episodes, causing small-vessel obstruction due to sickling of red blood cells in hypoxic conditions. Any situation which could promote this must be avoided. In the clinic this applies to techniques such as the use of tourniquets and tight dressings.
Table 17.12
Patients suffering from vitamin B12 deficiency are at risk of neuropathic ulceration, due to peripheral sensory neuropathy. The haematological system is also very useful as an aid to diagnosis. Case history 17.3 gives an example of where simple haematological tests prove diagnostic for a rheumatological condition which has contributed to an at-risk foot. Such tests can be useful for staging of this disease (Ch. 13).
Case history 17.3 Mrs Black is a 50-year-old school dinner lady. She was diagnosed with rheumatoid arthritis 6 years ago following an acute episode in which her toes and fingers became painful and swollen. She has been prescribed prednisolone to control her inflammation during acute attacks. Her feet have become deformed with severe hallux abductovalgus deformities, digital retraction, plantar metatarsal bursae and associated callosity. She finds it difficult to walk during acute stages of her disease. Recent blood tests confirm the presence of rheumatoid factor (immunoglobulin M: IgM) and she has both high erythrocyte sedimentation rate and C-reactive protein level, indicative of severe or prolonged inflammation. Recently, the medial eminence of her left hallux valgus deformity has ulcerated and she has presented with an acute infection of this lesion. She has been prescribed Augmentin to manage her current infection. Her footwear is inappropriate, being slip-on style. Mrs Blackfinds laces or other methods of fastening difficult, owing to her hand pain and loss of dexterity. Her peripheral perfusion is good, with Tcp02 levels of 60 mmHg and normal ankle: brachial pressure indices. She has no significant neurological dysfunction.
Lower limb disease and haematological disorders
Condition
Effects on lower limb
Sickle cell anaemia
Chronic punched-out ulcers around the ankle, aseptic necrosis of femoral head, peripheral vascular disease Leg ulcers Glove and stocking anaesthesia, loss of vibration and position sense, muscle weakness Increased riskof thrombosis and haemorrhage Risk of haemorrhage, bleeding into jointswith eventual destruction
Thalassaemias Pernicious anaemia (Vitamin B12 deficiency) Polycythaemia Haemophilia
THE AT-RISK FOOT
Musculoskeletal system There are a wide range of diseases in this category, many of which reduce tissue viability. Joint conditions producing foot deformities threaten tissue viability when unaccommodating footwear is worn or when the tissue overlying the deformity is not protected from ground reaction forces. Rheumatoid arthritis. This is an inflammatory joint condition characterised by rapid subluxation and deformation of joints, especially of hands and feet, giving rise to ulnar deviation of the hands and hallux abductovalgus deformity of the feet. In 70% of cases it is correlated with the presence of the rheumatoid factor, an antibody produced in response to the altered immunoglobulin M (IgM) antibody which acts as the trigger for autoimmune destruction of joint structure. In addition, rheumatoid arthritis is characterised by formation of soft tissue nodules over subluxed joints, by atrophic skin, muscle wasting and weakness and vasculitis. All these factors compromise tissue viability. Nodules are likely to break down due to pressure and form deeply perforating ulcers. Muscle weakness leads to vascular stasis and this, combined with thin skin, increases the likelihood of ulceration. Vascular involvement in rheumatoid arthritis may be limited to discrete digital ateritis, forming small lesions in the skin of digits around nails folds or may involve a generalised vasculitis, leading to thrombotic lesions of larger vessels and leading to dry gangrene. Sadly, in such cases, internal organs such as the heart are also likely to be affected, often with fatal outcomes. Vasculitis may also affect the vasa nervorum, leading to peripheral sensorimotor neuropathy with subsequent deformities such as foot drop and with the tissues being at risk of unnoticed trauma. Sero-negative arthritides (e.g. psoriatic arthritis, Reiter's disease, ankylosing spondylitis, enteropathic arthritis, Behcet's disease) are a range of arthritic conditions which, like rheumatoid arthritis, are inflammatory processes, but which all test negative for the rheumatoid factor and show a marked correlation with the presence of the HLA B-27 antigen. They share certain char-
445
acteristics in common, although not all characteristics will be displayed in each case. All show a tendency to involve the sacroiliac joints as well as peripheral arthritis. Their effects on lower limb tissue viability varies from one condition to another. Psoriatic arthritis. This condition tends to involve terminal interphalangeal joints which may precede skin and nail lesions by months or years. Although slowly progressive, the condition can be extremely destructive, causing absorption of the phalanges. Deformities and skin lesions all compromise tissue viability. Reiter's disease. This condition is usually sexually transmitted and almost entirely confined to males. The inflammatory arthritis involves toes, ankles and knees and painful heel is a common symptom. Skin and nail lesions (keratodermia blennorrhagica) closely resemble those of psoriasis. Both the joint deformities and skin lesions compromise tissue viability. Ankylosing spondylitis. This condition affects males far more often than females, but here the spine, hips and shoulders are usually affected. The feet are rarely involved and the condition has little effect on tissue viability of the lower limb. Enteropathic arthritis. Linked to Crohn's disease, enteropathic arthritis shows a flitting peripheral arthritis of lower limb joints, which remits as the bowel disease improves. Effects on tissue viability of the lower limb are transitory. Behcet's disease. This is a rare condition which, in addition to peripheral arthritis, exhibits vasculitis, venous thrombosis and neurological defects. The patient is therefore at increased risk of gangrene and amputation. Other inflammatory conditions which do not belong to the preceding groups are gout and infective arthritis. Gout. Gout is an inflammatory condition produced by the presence of high levels of uric acid, which crystallises out in joints, provoking an inflammatory response. The most common site is the first metatarsophalangeal joint, producing symptoms of acute pain, swelling and inflammation. Even if untreated, the symptoms subside after 2-3 weeks and tissue viability returns to
446
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normal, but if repeated attacks occur, crystalline deposits eventually cause destructive changes in articular cartilage and underlying bone, with permanent deformities. In severe cases, tophaceous ulcers may arise - especially over bony prominences. Infectious (syn: septic,
pyogenic) arthritis.
Infectious arthritis is a rapidly evolving inflammatory condition that can destroy a joint very quickly if not arrested. The condition is usually extremely painful and a portal of entry can usually be detected. Patients particularly at risk of this condition include those on long-term steroid therapy or on immunosuppressive drugs. Degenerative joint conditions. Conditions such as osteoarthrosis also result in deformities but are usually slow to develop. The metatarsophalangeal joint of the first digit is the most commonly affected joint, giving rise to a hallux limitus/rigidus or hallux valgus deformity. They are often the result of injury or the wear and tear of ageing. Connective tissue disorders. These disorders have many features in common, especially vasculitis and fibrosis of ground substance. Each is a multisystem disease with variable characteristics: several, including systemic lupus erythematosus, polyarteritis nodosa, polymyositis and dermatomyositis exhibit muscle and joint pains. The vasculitis can lead to partial or total obstruction of small vessels, in turn resulting in tissue necrosis.
Table 17.13
Neurological system We have already seen how degeneration of the peripheral nervous system, as seen in diabetes mellitus, can lead to profound deterioration in tissue viability of the lower limb. Other conditions (Table 17.13) can also produce peripheral neuropathy with similar associated high-risk problems. Conditions affecting the spinal cord produce symptoms which can be those of a sensory and/ or a motor deficit, depending on the areas affected. Examples are syringomyelia (sensory and motor); motor neurone disease (motor only); tabes dorsalis (tertiary syphilis)(sensory only); subacute combined degeneration (vitamin B12 deficiency) (sensory and motor) and Friedreich's ataxia (sensory and motor). Demyelinating diseases such as multiple sclerosis also produce combined symptoms - in this case, upper motor neurone symptoms and sensory loss. In addition trauma, disc protrusion and neoplasms can all produce acute sensory and motor symptoms. Conditions affecting the brain such as strokes can produce symptoms of hemiplegic or quadriplegic upper motor lesions or contralateral sensory impairment. Impaired sensory perception is a severe threat to tissue viability, since it may rob the person of the pain-warning system which normally alerts the person to imminent or actual injury. Postural instability, as seen in Parkinson's
Conditions producing peripheral neuropathy of the lower limb
Condition
Effect
Alcoholism Charcot-Marie-Tooth disease (peroneal atrophy) Connective tissue diseases, e.g. rheumatoid arthritis, systemic lupus erythematosus, polyarteritis nodosa, sarcoidosis Drugs, toxins Gutllaln-Barre syndrome Hansen's disease (leprosy) HIV/AIDS Malignancies Poliomyelitis Trauma
Sensorimotor neuropathy Predominantly motor neuropathy Sensory or mixed neuropathy, mononeuritis multiplex Generalised neuropathy Predominantly motor neuropathy Sensory neuropathy Distal symmetrical polyneuropathy Predominantly sensory Motor neuropathy Sensorimotor neuropathy
THE AT-RISK FOOT
disease, renders the person liable to falls. Motor neuropathies threaten tissue viability by creating deformities leading to high pressure points which make the tissue vulnerable during everydayambulation. For a fuller discussion of neurological conditions and their effects on the lower limb, the reader is directed to Chapter 7. Renal system
Chronic renal failure results in a failure of the kidney to carry out its important regulatory roles of water and electrolyte balance, acid-base balance, production of active vitamin 0 3 and production of haemopoietins. Even with dialysis, careful diet and medication, these disturbances can lead to hypertension and thus increase the risk of atherosclerosis or occasionally lead to peripheral neuropathy. As the delicate calcium: phosphate balance is disturbed, hypocalcaemia and hyperphosphataemia occur, leading to an increase in parathyroid hormone and bone resorption with rickets or osteomalacia as a consequence. Anaemia can result from lack of erythropoietin. Chronic glomerulonephritis which is characterised by diffuse sclerosis of the glomeruli, is usually accompanied by hypertension. A familial disease of the kidney which also results in rickets is characterised by impaired renal resorption of phosphate and reduced intestinal absorption of calcium. This in turn leads to resorption of bone to raise plasma calcium levels, resulting in rickets or osteomalacia. It is called vitamin O-resistant rickets to distinguish it from the deficiency disease. Respiratory system
Chronic diseases affecting the respiratory system, such as chronic obstructive airways disease, chronic bronchiectasis, silicosis or asbestosis, will affect the ability of the lungs to fully oxygenate the blood pumped from the right ventricle. Poorly oxygenated blood will then be delivered to the tissues and will impair healing ability.
447
CLINICAL DECISION MAKING The role of the practitioner in assessing the atrisk foot is to achieve a rational diagnosis based on key facts from the history, presenting problem and physical examination of the patient. It is important to recognise that in many cases the patient will be consulting several health professionals about the primary underlying disorderts) which have placed their feet at risk. The lower limb practitioner should ensure liaison with these other professionals to ensure that all practitioners involved are in possession of the full facts relating to the case, and that effective shared care can be planned. In many cases patients will have more than one, or even multiple causes for their at-risk feet. It is important to identify all potential risk factors when assessing the patient. Failure to do so can render management ineffective, delay resolution or in severe cases result in deterioration of the patient. The key to full identification of risk factors is a comprehensive and systematic physical examination and history-taking approach. Communication, and where necessary, referral to other agencies or health professionals is of utmost importance when dealing with the atrisk foot. It is important for the lower limb practitioner to ensure that the patient's general medical practitioner is aware that the patient has an at-risk foot, reasons for this risk status, the chosen management plan, and that he is informed when the patient's foot health status improves or deteriorates. Similarly, if the patient is under the shared care of hospital medical or nursing staff, the lower limb practitioner should ensure that these are likewise kept informed. From time to time the lower limb practitioner will fail to achieve the desired therapeutic intentions. For example, an ulcer may fail to heal, infection may spread, or pain may become difficult to manage. In these cases the practitioner should recognise as early as possible that the treatment being provided is not able to bring about the desired therapeutic effect. In these cases the patient should be referred to the practitioner best suited to provide intervention, which
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may be outside the scope of practice of the referrer. Such a referral should not be seen as an admission of failure, rather part of an overall management plan. The earlier into the process this referral takes place, the better the likely outcome for the patient. Many patients have suffered because practitioners have failed to recognise that they are no longer in a position to help the patient. Typical indications for referral to medical or surgical colleagues are presented in Table 17.14. Practitioners should recognise the importance of review and reassessment of at-risk patients. Most people working with the at-risk foot have felt a sinking feeling when an at-risk patient has failed to attend several consecutive appointments, only to find that the patient has deteriorated and either been hospitalised or is sick at home. Assessment and diagnosis is not an exact science at the best of times. In cases of high risk, and in situations where rapid change is likely, it is therefore important to keep diagnosis and treatment plans under review. Formal reassessment of the patient should be undertaken at regular intervals. Shorter intervals for reassessTable 17.14
ment will clearly be necessary for patients with risk factors which are likely to undergo rapid change (e.g. infection). Second and even third opinions are often good practice when dealing with the at-risk foot. The lone practitioner is often not the best option for the patient with severe foot disease. Practitioners need to be sure that they have reached a correct diagnosis, have devised appropriate and achievable therapeutic objectives, and have put in place effective management strategies. The views of another practitioner (podiatric, medical or nursing) can be invaluable in ensuring effective clinical care for high-risk cases.
SUMMARY Management of the at-risk foot can be a challenging but highly rewarding area of clinical practice. This is an area of medicine with a growing and strong evidence base. Practitioners practising in this area need to be committed to continuing professional development to ensure that they are capable of practising safely, effectively and with up-to-date knowledge.
Indications for medical or surgical referral
Indicator
Indicative referral
Potential outcome
Severe ischaemia Deteriorating wound • Extensive necrosis • Risk of infection
Vascular surgeon Orthopaedic surgeon
Reconstructive surgery Amputation
Spreading infection Cellulitis Pyrexia • Osteomyelitis • Systemic spread
GP Consultant physician Surgeon
Systemic antibiotics Intravenous antibiotics Surgical debridement or amputation
Worsening medical/physical state • Sudden loss of weight • Malaise Fatigue • Change in conscious level
GP Consultant physician
Medical review or hospitalisation
Failure to prevent weightbearing
GP or hospital consultant
Hospitalisation for total bed rest
Pain which cannot be managed by over-thecounter remedies
GP
Prescription analgesics
Unusual/suspicious changes in lesion
GP or dermatologist
Biopsy or excision
Extreme anxiety, depression or stress
GP or psychiatrist
Psychiatric evaluation
Onset of confusion and/or dementia
GP or psychiatrist
Psychiatric evaluation
THE AT-RISK FOOT
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REFERENCES Armstrong D G, Lavery LA, Harkless L B 1998 Validation of a diabetic wound classfication system. Diabetes Care 21: 855-859 Carlson G L 1999 The influence of nutrition and sepsis upon wound healing. Journal of Wound Care 8: 471--474 Cotran R S, Kumar V, Robins S L 1994 Pathologic basis of disease. W B Saunders, Philadelphia, p 484 Edmonds M E, Foster A V M 2000 Managing the diabetic foot. Blackwell Science, Oxford, pp 3,17-22 International Working Group on the Diabetic Foot 1999 International Consensus on the Diabetic Foot, pp 12, 66-67 Lavery L A, Armstrong D G, Harkless L B 1996 Classification of diabetic foot wounds. Journal of Foot and Ankle Surgery 35: 528-531 Macfarlane R M, Jeffcoate W J 1999 Classification of diabetic foot ulcers: the SCAD) SAD system. The Diabetic Foot 2: 123-131 Margolis D J, Kantor J, Berlin J A 2000 In: Boulton A J M, Connor H, Cavanagh P (eds) The foot in diabetes. John Wiley and Sons, Chichester, p 63 Mason J, O'Keefe C, McIntosh A, Hutchinson A, Booth A, Young R J 1999 A systematic review of foot ulcers in
patients with type 2 diabetes mellitus. 1: prevention. Diabetic Medicine 16: 801-812 Oyibo S 0, Jude E B, Tarawneh I et al 2001 The effects of ulcer size and site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers. Diabetic Medicine 18: 133-138 Rajbhandari S, Harris N D, Sutton M et al1999 Digital imaging: an accurate and easy method of measuring foot ulcers. Diabetic Medicine 16: 339-342 Richard J L, Daures J P, Parer-Richard C, Vannereau 0, Boulot I 2000 Wounds 12: 148-154 Schubert V 1997 Measuring the area of chronic ulcers for consistent documentation in clinical practice. Wounds 9: 153-159 Serra L 2000 Clinic currently testing the SCAD) SAD classification system -letters. The Diabetic Foot 3: 10 Sims D S, Cavanagh, Ulbrecht J S 1988 Risk factors in the diabetic foot. Recognition and management. Physical Therapy 68: 1887-1902 Young M 2000 Classification of ulcers and its relevance to management. In: Boulton A J M, Connor H, Cavanagh P (eds) The foot in diabetes. John Wiley and Sons, Chichester, pp 61-62
FURTHER READING Banks V 1998 Wound assessment methods. Journal of Wound Care 7: 211-212
Letters 2000 The Diabetic Foot 3: 42
CHAPTER CONTENTS
Introduction
451
Assessmentof the. elderly population
452
Definitions of ageing 453 Lower limb consequencesof ageing 453 Assessmentof the elderly 455 Assessment of the elderly vascular system 455 Assessment of the elderly neurological system 456 Assessment of the elderly musculoskeletal system 457 Assessment of elderly skin 458 Assessment of the elderly endocrine system 459 Assessment of the elderly haematological system 459 Assessment of the elderly respiratory system 460 Functional assessment of the elderly 461 Assessment of gait in the elderly 462 Determinants of the quality of life 463 Assessment of cognitive status 463 Assessment of ability to perform basic foot care 464 Risk assessment and the elderly 465 Summary 466
Assessment of the elderly W Turner
INTRODUCTION The majority of people seeking advice for foot problems are over the age of 65 years. Surveys of podiatry caseloads identify people over this age as the largest consumers of foot health services. As the population ages, so the demands on providers of foot health services are likely to increase. It is, therefore, essential for elderly people to receive a structured and systematic assessment of their foot/lower limb problem if effective care is to be provided. Whereas the general principles of assessment of the lower limb apply to the elderly, there are some particular considerations which practitioners need to consider when assessing the elderly. Growing old is sometimes perceived as a disease process. However, unlike a disease, growing old is an inevitable, time-dependent process which will occur to all individuals, providing that life is not prematurely ended. Ageing is therefore an unstoppable process for which there is no escape or cure. The role of the practitioner is, therefore, to minimise the effects of age-related degeneration of body systems, and to enable the elderly to compensate for such changes. The aim of any intervention is to enable the elderly person to continue to meet the challenges presented to them by their particular environments and circumstances. For example, a painful bunion joint may prevent an elderly person walking to the shops. Appropriate foot care provision may relieve the patient's pain and improve physical function, thereby 451
452
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enabling the patient to walk to the shops without pain and discomfort. Even relatively simple foot problems, such as neglected long toe nails, can limit an individual's ability to cope with the demands of daily living. Nail problems may prevent a person from wearing outdoor shoes, and therefore restrict the person's living environment to their home. Such confinement can result in social isolation, causing further health deterioration and severe reductions to the quality of life.
ASSESSMENT OF THE ELDERLY POPULATION The size of the elderly population has increased over the last century. For example, in the United Kingdom, the number of people of pensionable age has risen from 2 million in 1901 to 10 million in 2001 - Office for Census and Population Statistics (OPCS) data. In the UK, the over 65s now make up around 20% of the general population. Reasons for improved longevity include improved water and sewage treatment, better nutrition, improvements in housing and better social and economic circumstances. The impact of improvements in medical care on average life span is less quantifiable. Community podiatry services predominantly provide foot health services to people over the age of 65 years. In 1997 a total of 975 000 new referrals were made to NHS podiatry services in the United Kingdom. Of these, 63% (614250) were for people aged 65 years or over (Hansard 1998). In the same year, a total of 9 million face-
Table 18.1
to-face contacts were carried out by community podiatry services, costing a total of £99.6 million (US$149 million). The prevalence of foot morbidity amongst elderly populations is difficult to determine. There have been relatively few studies which have quantified foot morbidity amongst the elderly. In those surveys of foot morbidity which have been published, the most commonly reported foot problems amongst the elderly were difficulties with nail cutting, corns and hard skin, respectively (Crawford et al 1995). In the same survey, around half of people over the age of 75 years complained of two or more foot problems. A recent meta-analysis of the literature shows forecast prevalence data for foot pathologies for populations over the age of 65 years (Table 18.1). However, this does not include studies of high-risk groups (e.g. people with diabetes) and probably underestimates the true prevalence of foot conditions in general populations. The large standard deviations and confidence intervals for many of the pathologies reviewed demonstrate the relatively high variation of reported prevalence of foot disease in the literature. Nevertheless, these data can be used to provide a rough estimate of foot morbidity for a given population. There is certainly evidence that the likelihood of experiencing foot problems, and the likely need for community foot health services, increases with advancing age. This is particularly true for elderly women, who are the largest consumers of UK NHS podiatry services (Harvey et al 1997).
Forecast prevalence of foot pathologies amongst the elderly population (from Turner et a12001)
Condition Hyperkeratosis Hypertrophic nails Toe deformity Onychomycosis Hallux deformity Diminished sensation Vascular insufficiency Poor foot hygiene Foot ulceration
Mean prevalence 54.88 39.8 30.68 40 23.14 19.83 16.98 20.9 4.15
95% confidence interval 47.78, 19.76, 9.91, 16.77, 14.77, 14.69, 10.4, 4.99,
0,
61.98 59.84 51.45 63.23 31.51 24.97 23.56 36.81 8.36
Standard deviation 11.46 14.42 23.64 23.7 9.56 4.54 7.52 11.45 3.04
ASSESSMENT OF THE ELDERLY
453
DEFINITIONS OF AGEING
Table 18.2
The fact that ageing is a reproducible and predictable process enables recognition of the signs of ageing to be made. Ageing is a process beginning at conception and continuing until death. The medical concept of ageing is to treat ageing as a disease process. However, ageing is not a disease, in spite of the fact that as one ages diseases become more common. The elderly, therefore, experience greater numbers, variety and severity of diseases than the young. However, for a process to be due to ageing, it must be universal, progressive, intrinsic and deleterious (Bennett & Ebrahim 1995). It is not surprising, therefore, that the elderly are the greatest users of health care services. Arbitrary conventions tend to define 'the elderly' as those over the age of 65. For the purposes of population assessment, it is probably more helpful to divide this group into three more distinct categories (Bennett & Ebrahim 1995):
Group
Characteristics
Young old 65-74 years
Recently retired Active Generally fit Independent Often able to drive Able to take vacations Relatively wealthy Wide social network Often care providers to 'oldest old' parents/relatives
Old old 75-85 years
Often widowed Increasing number of minor medical problems Increased likelihood of major medical problems Becoming less mobile Often unable to drive Dependent on public transport Rarely take vacations Generally not wealthy Social network reducing, owing to death of friends/relatives
Oldest old 85 years +
Usually widowed Coping with major and minor medical problems Generally poor Dependent on others to assist with everyday tasks Unable to drive Travels for essential purposes only Usually does not take vacations Physical limitation to activity Social network confined to close friends/relatives/carers
• 65-74 years: the young old • 75-85 years: the old old • 85 years + the oldest old.
Typical characteristics of each group are given in Table 18.2.
Typical characteristics of elderly groups
LOWER LIMB CONSEQUENCES OF AGEING The lower limb often suffers the degenerative effects of ageing owing to the fact that the foot is a weightbearing structure which bears the stresses of years of supporting and carrying the body. As tissues deteriorate with advancing years, disruption to the normal structure and function of the foot is inevitable. Structural change (e.g. joint disease, skin callus) will invariably lead to a degree of loss of function, with more severe structural disturbances leading to greater functional impairment. Individuals are often able to compensate for minor structural deterioration in order to retain functional ability. Multiple minor structural defects or single major defects are likely to result in failed compensation and adversely affect functional ability.
From an assessment point of view, it is helpful to determine what the individual patient is able and unable to do. Functional ability is affected by disease and/or the compensatory (coping) mechanisms for the effects of disease. For example, an elderly person may be unable to cut her nails. The person is, therefore, defined as being functionally unable to perform that activity. The practitioner may be able to determine a range of diseases/age-related changes which have resulted in this functional deterioration. Often for any given individual, a combination of coexisting factors contribute to functional loss. Deterioration of vision, arthritic fingers, joint diseases affecting the hips / spine, hiatus hernia and motor weakness are typical examples of
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conditions which commonly lead to such loss of function. Table 18.3 identifies common structural changes which occur to tissues of the foot and which are related to the ageing process. Most elderly people will frequently show signs of one or more of these structural changes. The underlying mechanisms responsible for such changes are complex and often relate to combined, multiple degeneration arising in other systems (e.g. vascular, endocrine and neurological systems). Common foot pathologies seen in the elderly are often not directly related to the physiological effects of ageing but to the chronic, longterm exposure to exogenous factors (Table 18.4). For example, age-related changes to the skin are most likely to arise as a result of a lifetime of exposure to ultraviolet light. In the absence of Table 18.3 foot
Age-related structural changes to tissues of the
Skin
Skin moisture content reduces Skin becomes drier Skin more prone to fissuring Skin is less flexible/elastic Skin becomes weaker, more likely to tear or split Atrophy or displacement of subcutaneous fat may occur Weightbearing forces on skin increase as foot function worsens Hyperkeratotic lesions become more likely Number of pigmented lesions is likely to increase Extravasation of blood into skin is more likely Loss of skin viability is more likely as a result of deterioration in circulation
Nail
Rate of nail growth reduces Nail plate becomes drier Nail plate becomes thicker Increased likelihood of debris/callus in nail sulci or beneath nail plate. Increased incidence of subungual lesions Involution of nail plate more likely Nail plate becomes more brittle, and liable to split/crack
Joints
Increased likelihood of degenerative arthropathy in weightbearing joints. Long-term compensation for functional foot abnormalities likely to contribute to joint pathology (e.g. hallux valgus, hallux limitus) Thickening of joint margins with resultant decreased range of motion is likely Overall mobility of foot joints reduced Increased likelihood of joint deformity
Table 18.4 Exogenous factors associated with age-related changes to the foot
Ultraviolet light (sunlight) Diet Smoking Alcohol consumption Chemicals/drugs Occupation Sports, hobbies and activities Trauma Footwear Cosmetics
exposure to sunlight the skin ages very little with time. The action of ultraviolet light exposure to skin results in the production of free radicals which have a long-term damaging effect on cells. Many skin disorders which are commonly associated with ageing are related to ultraviolet exposure (Table 18.5). The foot is often at a reduced risk of these ultraviolet light lesions compared with more exposed parts of the body (e.g. the face), owing to the fact that for most people for most of the time the skin of the foot is covered by footwear. Foot disorders which occur as a direct result of ageing tend to be associated with general systemic (intrinsic) disease. The incidence of systemic disease increases with advancing age. Elderly people are also more likely to have several coexisting systemic disorders. The combined effects on the foot of several systemic diseases occurring simultaneously can be significant. Assessment of the elderly patient should always, therefore, include a full and comprehensive medical history Table 18.5 Skin conditions seen in elderly people associated with lifelong exposure to sunlight
Wrinkles Hyperpigmentation Hypopigmentation Solar keratoses Basal cell carcinoma Squamous cell carcinoma Malignant melanoma Dry, inelastic skin
ASSESSMENT OF THE ELDERLY
and physical examination. Likewise, a familial history is also important in assessment of the elderly patient. The consequences of lower limb disease for the elderly patient can be significant. Foot disorders can make a significant contribution to the risk for falls, loss of mobility, loss of independence, inability to carry out activities of daily living, pain, depression, social isolation, deterioration of quality of life, loss of tissue viability and amputation. What may appear to be minor foot pathology can have a significant effect on the lifestyle of the patient. The assessment of the elderly patient should therefore seek to determine how the patient's foot health is affecting lifestyle. It is also important to bear in mind that conditions can deteriorate very quickly for elderly people. What is a minor problem one day can become a major limb or life-threatening problem the next. There are several reasons why pathologies in the elderly patient are likely to deteriorate faster. These include a less effective immune system, poor peripheral circulation, diminished peripheral sensory perception, motor weakness, confusion, loss of tissue resilience, combined systemic pathology, effects of drugs, inability to self-care, poor nutrition, poor hygiene and inadequate footwear. Evidence for rapid change of foot health amongst an elderly population has recently been borne out of a study of the discharge of elderly patients from a community podiatry department (Turner et al 2001). In this study 5000 people over the age of 65 who were assessed as being of 'low risk' for serious foot pathology were discharged from the service. Within a 2-year period following discharge 712 (14%) of these patients were re-referred to the department with serious foot problems which caused them to be classified as 'high risk' according to the department's criteria. Reasons for re-referral included infection or ulceration (162 re-referrals), diabetes (178 re-referrals), peripheral vascular disease or neuropathy (310 re-referrals), increased risk due to change of medication (62 re-referrals). Practitioners need to be aware that assessments of the foot health status of elderly patients,
455
and in particular risk assessment, can only represent foot health status at a specific point in time. Inferences for the future foot health needs of a patient based on such 'snapshot' assessments carry significant risks. A single major event - e.g. cerebrovascular accident (eVA), trauma and infection - or multiple minor events (e.g. neglect of self-care, minor trauma, change to footwear) can have a dramatic effect on an individual's foot health status. Since the occurrence of these events is unpredictable in elderly people, it is important to review or reassess the foot health status and needs of the elderly patient regularly.
ASSESSMENT OF THE ELDERLY The practical approach to the assessment of the elderly patient varies little from the standard approach to assessment. However, some additional points are worthy of consideration. For several systems, assessment will take the form of history taking and physical examination (e.g. vascular, neurological, orthopaedic, dermatological). For some systems, history taking alone is normally required (e.g. endocrine, renal). Specialist tests or investigations may be required for complete assessment of other systems where appropriate (e.g. respiratory, haematological).
Assessment of the elderly vascular system Leonardo da Vinci cheerily recognised the importance of vascular degeneration in the elderly when he wrote: veins which by the thickening of their tunics in the old, restricts the passage of their blood and by this lack of nourishment destroys the life of the aged without any fever, the old coming to fail little by little in slow death (in Bennett & Ebrahim 1995) Age-related changes to the vascular system in the elderly arise as a result of age-dependent (physiological) changes and disease (pathological) processes. It is thought that the physiological changes contribute very little to the overall deterioration of vascular function, and that disease processes are more significant (Wei 1992).
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The most significant changes to the arteries include calcification of the tunica media (arteriosclerosis), fibre-fatty occlusion of the vessels (atherosclerosis) and arterial complications of these processes (aneurysm, thrombosis, embolism). The prevalence of peripheral arterial insufficiency amongst the elderly is around 16% (Turner et al 2000). One of the most important factors contributing to the pathology of arterial disease in the elderly is elevation of arterial blood pressure. Both systolic and diastolic pressures tend to rise with advancing age. The reasons for this are complex, but include increased peripheral resistance and physical fitness. To reduce the risk of age-related arterial disease, control of blood pressure is important. It is therefore beneficial for all patients to have their blood pressure reviewed at least annually. Treatment for high blood pressure is generally beneficial in terms of improvements to mortality and morbidity up to the age of 80 years. However, side effects of antihypertensive therapy (especially diuretics) in the elderly can be significant and lead to additional health concerns, including postural hypotension, falls, dehydration and occasionally gout. Apart from hypertension, other major risk factors for arterial disease in the elderly include hyperglycaemia and hyperlipidaemia. Undetected or poorly controlled diabetes mellitus is the commonest cause of hyperglycaemia in the elderly. Early detection of impaired glucose tolerance (or elevated glycosylated haemoglobin levels) coupled with resultant management of hyperglycaemia is therefore useful in the longterm prevention of vascular disease. Similarly, screening for hyperlipidaemia and where appropriate dietary modification and/or use of lipid lowering drugs can be important in an overall plan of action to reduce an individual's risk of vascular disease. The consequences of poor arterial supply to the feet vary from minor changes to poorly nourished tissues, like dry skin, brittle nails, hair loss, atrophy of fat pad, to more severe foot problems like ischaemia, ulceration and gangrene. A structured vascular assessment as detailed in Chapter 6 is, therefore, essential for all elderly patients.
Deterioration of the peripheral venous system is also common in elderly people. Venous hypertension in the elderly may arise as a result of right-sided congestive heart failure, lack of exercise (inactive skeletal muscle pumps), valvular dysfunction, deep vein thrombosis, venous occlusion, respiratory disease (poor respiratory pump mechanism) or abdominal masses (e.g. tumours). The lower limb consequences of venous hypertension include venous stasis eczema, venous ulceration, oedema, hyperpigmentation (especially haemosiderosis) and in rare, usually long-standing cases, malignant (fungating) wounds. The role of the inter-professional team is important in conducting an assessment of the vascular system in elderly patients with peripheral vascular pathologies. Frequently, patients who demonstrate lower limb signs of peripheral vascular disease will also have coexisting vascular degeneration affecting other tissues and organs of the body (e.g. kidney, eye, brain, heart). Similarly, vascular disease affecting multiple organ systems is a good reminder to the practitioner to conduct a thorough assessment of the lower limb vascular supply. As previously stated, the elderly patient is susceptible to rapid change in vascular status. Therefore, frequent reassessment and update of vascular assessment is necessary, especially for the 'old old' and 'oldest old' patients who are likely to be most at risk.
Assessment of the elderly neurological system Age-related changes to the peripheral nervous system can result in deficiencies in the motor, sensory or autonomic nerves of the lower limb. Signs of such deficiencies include defects of sensory perception, muscle weakness, deformity, dry skin and vasodilation. The literature suggests that defective sensory perception is present in around 20% of people over the age of 65 years (see Table 18.1). The prevalence of peripheral neuropathy is greatest in older people with diabetes mellitus, where up to 43% of people can be expected to have some
ASSESSMENT OF THE ELDERLY
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abnormal neurological assessment findings (Plummer & Albert 1996). Loss of vibration perception as detected by the use of a tuning fork, and loss of touch/pressure sensation as detected by a 10 g monofilament are the commonest findings in the elderly. The likely presence of neurological abnormalities increases with advancing age. Defects affecting upper motor neurones are often related to disorders which occur more frequently in the elderly (e.g. CVA). These disorders may result in severe functional disturbance, and limit mobility. Disorders which a younger person could normally compensate for are often difficult for an elderly person to adjust to. Reasons for failure to compensate for neurological disturbance might include limited capability to re-learn skills (rehabilitation), coexisting or multiple pathologies and severity of disruption to normal function. As a result, many elderly lose a degree of mobility and independence following a sudden deterioration in neurological function. Key neurological indicators include those tests described in Chapter 7. However, practitioners should avoid making long-term predictions of risk based on clinical assessment. As for vascular assessment, deterioration in neurological function can occur suddenly and may go undetected by the patient. Regular review of neurological status is important in the overall risk management of people over the age of 65, and is particularly important for those over the age of 85 years. Deterioration of nervous system function in the elderly is often clinically significant because other systemic problems coexist. Many elderly people with peripheral sensory neuropathy will also have some degree of vascular insufficiency, and also foot deformities. Abnormal weightbearing pressures, poor footwear, skin lesions, poor hygiene & self-care or trauma can therefore place the patient at high risk of loss of tissue viability. The relationship between foot neuropathy and foot ulceration is a significant one. In one study of 308 patients, 28% of people who could not detect a 10 g monofilament at any of 10 sites on the foot developed foot ulcers, compared with 3% of
people who could perceive the monofilaments at all sites (Plummer & Albert 1996).
Assessment of the elderly musculoskeletal system Musculoskeletal problems are extremely common in the elderly. Disorders such as osteoarthritis, osteoporosis and osteomalacia have an increased prevalence with advancing age. Deterioration of the musculoskeletal is responsible for much of the impaired mobility seen in elderly people. As far as the lower limb is concerned, the elderly are more likely to suffer from common lower limb disorders, including hallux valgus and lesser toe deformities. Around 23% of the elderly are likely to have hallux deformities and around 30% have lesser toe deformity (see Table 18.1). Practitioners are therefore likely to see the consequences of these deformities arising from pressure from footwear on deformed joints or normal weightbearing forces. These associated pathologies include corns, calluses, blisters and thickened or deformed toe nails. In patients with vascular or neurological deficit, ulceration is commonly seen to affect deformed toes. Assessment of the musculoskeletal system in an elderly person is not significantly different from that of a younger person. However, it is often impractical to examine joints of the hip and knee in as much detail (and as vigorously') as for young patients. It should be remembered that old people bruise easily, skin may be weak and joints unstable. Rough examination has the potential to cause the elderly severe discomfort or even harm. Most of the information about musculoskeletal system disease can be gained from gross examination and noting any obvious findings (e.g. obvious foot deformities, swollen joints, inflamed areas). The medical history may reveal a history of musculoskeletal disease (e.g. rheumatoid arthritis, osteoarthrosis, fracture, back problems). Observing the patient during walking can also provide important indications of functional ability. However, care should be taken with elderly people if using a motorised treadmill for
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the observance of gait. Elderly people may find it difficult to adjust their cadence to the speed of the treadmill, become unstable and/or fall. Another risk of treadmill use in the elderly is demanding unaccustomed levels of exercise from the patient and placing the patient at risk of acute ischaemia. This may manifest as acute skeletal muscle cramps, or (worse) acute angina or even myocardial infarction. Skin lesions are another useful indicator of musculoskeletal problems. Skin lesions such as corns or calluses tend to arise as a result of trauma to the skin exacerbated by deformed joints, difficulty accommodating the foot in appropriate shoes or compensation for functional pathologies. Elderly people are more likely to be offered conservative treatment for lower limb joint pathologies rather than surgical intervention. This is particularly true where the patient has complex or multiple systemic problems including cardiovascular or neurological disease. A significant proportion of elderly people are therefore prescribed drugs to manage musculoskeletal pain and inflammation. The most common category of drugs prescribed for this purpose is the nonsteroidal anti-inflammatory drugs (NSAIDs). Use of these drugs can result in gastric irritation and bleeding, particularly when used long term. Therefore, any elderly patient taking NSAIDs showing signs of anaemia or gastric disturbance should be more closely investigated.
Assessment of elderly skin As stated above, most of the changes to the skin which occur with advancing age do so as a result of cumulative exposure of the skin to ultraviolet light (sunlight) (see Table 18.5). Increased collagen cross-linking, drying and thinning of the skin are all a result of ultraviolet light exposure. Many of the effects of ageing on the skin can be prevented by avoidance of exposure to sunlight, or use of appropriate covers/barrier creams. Bruises and other vascular lesions are more likely in the elderly patient. These lesions arise as a result of increased capillary fragility, with capillaries more likely to leak blood into the skin. In the elderly patient reabsorption of extravasated
blood is much slower than in a younger person. These lesions are often collectively referred to as 'senile purpura'. Spider naevi, telangiectasiae and haemosiderosis are skin conditions which are more common in elderly people. These vascular /haemorrhagic skin lesions are more common and significant in elderly people taking anticoagulant drugs (e.g. warfarin) following thrombosis. Corns and calluses are likely to be a greater problem for the elderly. Dryness and reduced skin resilience predispose to hyperkeratotic skin lesions. In addition, the elderly are more likely to have functional foot pathology and/or deformities which cause abnormal weightbearing lesions or lead to problems accommodating the foot in shoes. Vascular or neurological impairment may then lead to reductions in tissue viability and infection, ulceration or gangrene. The elderly are more likely to be troubled by difficult toe nails. Nails become thicker and harder with advancing age. Years of repeated minor trauma from footwear can result in nail plate abnormalities. Periungual and subungual lesions may also be a problem (e.g. onychophosis). Inability to self-care may result from poor eyesight, back pain, hiatus hernia, arthritic fingers, hip pathologies or obesity. Neglect of simple routine nail care can result in potentially serious foot pathology (e.g. infection, ulceration), particularly where there are coexisting medical, vascular or neurological abnormalities. The skin of the elderly patient has a less effective immune function than younger skin. The number and function of Langerhans' cells and epidermotrophic lymphocytes reduce as a result of ageing. Skin infection is therefore more likely in old age. This is a particularly significant problem for elderly patients with hyperglycaemia, vascular insufficiency or on long-term steroid therapy. Some elderly people have very thin, 'papery' skin. This is known as 'transparent skin syndrome' and results in a skin which looks and feels a little like tissue paper. Skin becomes wrinkled and loose, has poor elasticity and bruises and bleeds very easily. Skin tears easily, and is slow to heal. Vascular /haemorrhagic skin
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lesions are very common. This syndrome is commonly associated with osteoporosis. A similar skin condition can be seen in some patients following long-term steroid treatment (e.g. for rheumatoid arthritis). Many elderly patients complain about severe itching of the skin (senile pruritus). This can be an important indicator of an underlying pathology. The practitioner should attempt to identify the cause of any pruritus. Table 18.6 identifies some of the common causes of pruritus in the elderly.
Assessment of the elderly endocrine system Endocrine dysfunction is more common in the elderly. The most significant endocrine disorder for the lower limb is diabetes mellitus. Type 2 (noninsulin-dependent) diabetes mellitus becomes much more prevalent with advancing age. The chronic complications of hyperglycaemia result in damage to nerves (neuropathy) and arteries (angiopathy). These disorders create an increased risk of infection, ulceration, gangrene and amputation, and account for significant morbidity for a large number of elderly people. The primary clinical signs of diabetes mellitus may often first be identified in the lower limb. Signs of neuropathy, recurrent skin infection or arterial disease in an elderly patient should always be followed up with testing for diabetes (e.g. glucose tolerance test).
Table 18.6
Causes of pruritus in the elderly
Excessive dryness of the skin Haematological disorder (e.g. polycythaemia rubra vera) Hepatic disease Renal disease Malignant disease Drugs Infestations (e.g. scabies, lice, fleas) Inflammatory skin diseases (e.g. eczema, psoriasis) Incontinence Autonomic dysfunction Hypersensitivity
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Other consequences of ageing include the menopause. In women the menopause is an inevitable consequence of ageing. It results in a depletion of oestrogen production, with a rise in the secretion of gonadotrophic hormones follicle-stimulating hormone (FSH) and luteinising hormone (LH). A reduction in oestrogen is associated with osteoporosis, dryness of the skin and flushing/sweating. Osteoporosis is a significant risk, and occurs because the bone cannot metabolise vitamin D and calcium without oestrogen. Pathological fractures may occur in response to relatively minor trauma in patients with advanced osteoporosis. The most significant site for osteoporotic fracture in the lower limb is the neck of the femur. Fracture at this site commonly occurs from falls and can be extremely disabling, and is even responsible for premature death in some people. Postmenopausal changes to the skin can result in dryness and increased fissuring of 'fatty' areas of skin. A common complaint in postmenopausal women is dry heel fissures, which may be inflamed and prone to bleeding. This condition is referred to as keratoderma climaciericum. It is aggravated by summer conditions (evaporation of surface water), excessive bathing (including foot spasl), open-backed shoes and hard soles. Thyroid dysfunction is also a common problem in the elderly, but can be difficult to diagnose or recognise. Hypothyroidism is a common finding in elderly people as a result of decreased secretion levels of thyroxine. The signs of hypothyroidism in the elderly may be subtle, and reflect common symptoms associated with being elderly. Signs include constipation, tiredness, dry skin and hair, weight gain and cold intolerance. Elderly people with hypothyroidism are at an increased risk of winter chilling: hypothermia is a significant risk for people with inadequate household heating or poor nutrition.
Assessment of the elderly haematological system Blood disorders such as anaemia can complicate an already compromised lower limb. Just
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- - - - - - - -----------------
because the foot is warm and has bounding pulses does not always guarantee adequate tissue nutrition. The quality of the blood is important too. Anaemia is relatively common in elderly people, and in mild cases can be difficult to recognise. Symptoms of anaemia can be slow to develop, and can be mistaken for 'growing old'. Lethargy, general malaise, intermittent claudication, pallor, headache, breathlessness, angina and skin atrophy are all features of anaemia but are also features which can be seen as part of the ageing process. The lower limb consequences of anaemia can be particularly significant for the elderly patient. This is particularly true if the anaemia is 'superimposed' on coexisting vascular disorders. Adequate tissue nutrition is dependent upon both adequate quantity and quality of blood reaching the tissues. Quantity is affected by change in the diameter and resilience of the blood vessels. Quality is affected by disorders of blood cells, oxygen-carrying capacity or increased tendency to form blood clots. Loss of tissue viability may occur where reductions in either the quantity or quality of blood fails to meet the basic nutritive requirements of respiring cells. The commonest types of anaemia to affect the elderly are iron-deficiency anaemia, pernicious anaemia and folate-deficiency anaemia. Irondeficiency anaemia commonly arises following haemorrhagic disorders, including those caused by gastric bleeding following long-term use of NSAIDS. In addition to the general symptoms of anaemia given above, clinical features of irondeficiency anaemia may include koilonychia (spoon-shaped nails) and brittle nails. Pernicious anaemia is a common form of anaemia seen in the elderly. The incidence is around 1 :8000 people over the age of 60 years. It arises as a result of vitamin B12 deficiency. Usually this occurs due to a lack of intrinsic factor, which is normally produced by the gastric parietal cells. Intrinsic factor is essential for the absorption of vitamin B12 in the ileum. Abnormalities of intrinsic factor secretion usually arise as a result of autoimmune processes. The disease is more common in people with other autoimmune diseases including thyroid disorders, Addison's
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disease and vitiligo. For males with pernicious anaemia, there is an increased incidence of gastric carcinoma. In addition to the general symptoms of anaemia, clinical features of pernicious anaemia may include weight loss and peripheral neuropathy. Peripheral neuropathy can be significant and is similar to that seen in diabetes mellitus. Posterior and lateral columns of the spinal cord are involved (subacute combined degeneration). Patients often complain of paraesthesia of toes, and demonstrate poor vibration perception, touch/ pressure sensation and proprioception. Progressive muscle weakness may result in digital deformity and ataxia. Other features may include a sore red tongue (glossitis), purpura and mild fever. Folate-deficiency anaemia is sometimes seen in elderly people and is associated with malnutrition. The daily requirement for folate is around 100 p.g. Dietary sources include green vegetables, kidney, liver and other offal. Cooking can destroy folate. Anaemia due to folate deficiency produces generalised symptoms as described above.
Assessment of the elderly respiratory system The respiratory system serves to oxygenate the blood and to eradicate waste gases from the body. Disorders of the respiratory system may therefore result in a failure to adequately oxygenate the blood, or an accumulation of waste gases. The latter condition results in acidosis, which is ultimately fatal. Assessment of the elderly patient should include observations of respiratory function. Age-related changes to respiration may include an elevated respiration rate, shallower breaths, altered chest sounds and chronic cough. These changes are more likely in people who are or have been smokers. Respiratory abnormalities may also lead to significant problems for elderly people with asthma, bronchitis, emphysema and congestive heart failure. Respiratory problems are a significant factor in the pathology of some lower limb disorders. As with many systemic conditions seen in elderly
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- - - - - - - - - - - - - - - - - - _ . - - _ ...- - - - - - - - - - _ . - - - - - - - - - - _ . _ - - - - - - - -
people, respiratory problems seen in combination with other coexisting disorders present the greatest threat. For example, elderly people with emphysema coupled with peripheral vascular disease may suffer ulceration of the foot. In this example, the reduction in oxygenation of the blood may complicate an already compromised tissue viability.
Table 18.7 Examples of functional assessments of the elderly patient Independence
What are the patient's capabilities? Can the patient carry out activities of daily living without assistance? Is the patient adequately compensating for the effects of disease? Can the patient adjust to changes in her environment? What does the patient need the help of other people to do? What does the patient's social network consist of?
Mobility
Is the patient able to move around her environment without assistance? Does the patient drive? Can the patient climb stairs safely? Can the patient manage to do her own shopping, visit hairdresser, chemist, doctor, etc.? Does the patient require special aids to assist her mobility (e.g. stick, frame, wheelchair)? Is the patient stable when standing or walking? Is the patient likely to fall?
Activities of daily living
What activities does the patient feel she needs to do on a daily basis? Can the patient cope with feeding and grooming herself? Can the patient dress/undress independently? Can the patient manage to cut her own toe nails and/or apply creams to the feet? Can the patient maintain a clean and hygienic home?
Quality of life
Is the patient satisfied with her life? Is the patient happy or sad? Is the patient lonely or isolated? Does the patient keep herself occupied? Are there things which the patient enjoys doing? Does the patient feel guilty about anything? Is the patient worried, frightened or concerned? Is the patient experiencing painful symptoms? Does the patient feel that physical disease or pain is affecting her lifestyle?
Cognitive state
Is the patient confused? Is the patient forgetful? Can the patient describe her symptoms? Is the patient capable of giving informed consent?
Functional assessment of the elderly Functional assessment of the elderly patient is an important part of the assessment process. A good functional assessment will provide the practitioner with a clear impression of a patient's capabilities and limitations and identify the effect of lower limb disorders on lifestyle. It will also assist with risk assessment of the elderly person. Table 18.7 details aspects of functional assessment which may be included as part of the general assessment of the elderly patient. Assessment of function before and after clinical intervention can be a useful means for the determination of clinical effectiveness. Some of the key therapeutic objectives for managing lower limb pathology in the elderly are concerned with the following: 1. maintaining or improving the patient's independence 2. improving the patient's mobility 3. improving the patient's quality of life 4. enabling the patient to undertake activities of daily living (ADLs). These objectives are as important as disease/ symptom specific objectives (e.g. reducing pain). Therapeutic interventions which have an effect on the above will often make a significant difference to the patient. This is true even where cure of the presenting problem is not possible. Most patients are more concerned about reductions in functional ability and becoming dependent on others (i.e, becoming a 'burden') than anything else. An inter-professional approach to therapy can be particularly useful to the assessment of function. Physiotherapists and occupational therapists, for example, make use of a variety of func-
tional assessment strategies which can provide the practitioner with useful information as part of an overall assessment of the patient.
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Functional assessment often focuses on the following: • mobility and independence • quality of life • ability to perform ADLs. In addition, there are other functional assessments which may be particularly relevant to the lower limb: • gait analysis • ability to self-care for feet. The most popular means of assessing mobility and independence is the Barthel index. This was first developed by Mahoney & Barthel (1965) for the assessment of long-stay hospital patients with neuromuscular or musculoskeletal problems. It has since been used for the assessment of community- (home-) based patients with a variety of pathologies. The index is designed for the assessment of function both before and after treatment. It is therefore useful for the determination of the efficacy of clinical intervention. Table 18.8 shows the key elements of the Barthel index. The Barthel index does not include some important activities of daily living such as shopping, cooking, social activities and gardening, which probably reflects the fact that the index was originally designed to assess institutionalised populations. Deterioration in independence and mobility usually progresses through: 1. Social activities of daily living - i.e. how the person relates to the 'outside world' - e.g. shopping, visiting friends and relatives, vacations, going to the pub, etc. Table 18.8
Key aspects of Barthel index
Feeding Mobility (from bed to chair) Personal toilet (washing, etc.) Getting on/off toilet Bathing Walking on a level surface Going up/down stairs Dressing Continence (bladder/bowel)
2. Domestic activities of daily living - i.e. how the person manages household tasks - e.g. cooking, cleaning, gardening, etc. 3. Personal activities of daily living - i.e. how the person manages to care for herself - e.g. washing, bathing, cutting toe nails, continence, etc. Therefore, an elderly person will usually experience difficulty with visiting the shops before having problems with cooking or bathing. Similarly, incontinence usually occurs later on after the person has developed other functional limitations. This can make continence a particularly difficult situation to manage for both the patient and carers. Many other factors often contribute to the onset of incontinence, including loss of mobility, urinary tract infection, autonomic neuropathy, prostatism, stress incontinence, unstable bladder, retention with overflow and central nervous system (eNS) pathology. There are a variety of means to test an individual's mobility. A simple mobility assessment is known as the 'timed up and go' test. In this test, the elderly person is asked to stand from a chair, walk 10 feet, turn and return to the chair. The person is timed during this activity. Most adults can complete this activity in less than 10 seconds. Frail elderly people may take from 11 to 20 seconds for this task. People taking longer than 20 seconds are generally amongst the most immobile elderly. For this latter group a more detailed mobility assessment is indicated. There is a strong association between the results of this test and a person's functional independence in activities of daily living.
Assessment of gait in the elderly Assessment of gait in the elderly patient can often be a useful indicator of mobility. It can also enable the practitioner to determine whether walking aids (e.g. sticks, frame) are indicated. A reduction in walking speed is one of the early features of gait disturbance in the elderly. Healthy adult cadence is about 1 m/s. A frail elderly person may walk at less than half this speed.
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Elderly stride length is often shorter than that of a younger adult. Gait is often apropulsive, with limited toe-off evident. This appears as a 'shuffling' gait. The base of gait is often wide, in an attempt to improve balance and stability. The elderly person may grasp fixed objects to improve stability. In this way, elderly people often use objects around their room to move around safely. This is especially common for elderly people with sight problems. Frail elderly people placed in an unfamiliar environment will often show a much slower and more 'unsure' gait than they would normally have at home. Lack of familiar objects for stability or an unfamiliar walking surface can cause perceptual problems and lack of confidence. Therefore, asking an elderly person to walk down a long corridor in a hard-floored clinic can give an unrepresentative picture of the person's gait. Gait is best observed in an environment which is familiar to the patient (e.g. home). Peripheral sensory neuropathy may produce a 'high stepping' gait with a characteristically heavy heel strike. Parkinson's disease produces a 'festinating' gait where the person appears to chase their centre of gravity forwards, shuffling and stooping. Musculoskeletal problems, joint pain or foot pain can result in an antalgic (painavoiding) gait. This often manifests as limping or avoiding certain movements or positions of the limb during gait.
Determinants of the quality of life Quality of life is affected by a complex interaction of multiple factors, some of which can have a large impact on quality of life (Table 18.9). There are many measurement tools for the assessment of quality of life. The most popular tool used in UK health care for the assessment of quality of life in studies of adults with disease states is the short form-36 questionnaire (SF-36). The SF-36 questionnaire consists of 36 questions divided into the following categories: physical health, physiological health, mental health and social well-being. Its popularity has resulted in a large number of studies which are able to attest
Table 18.9
Major factors affecting quality of life
Loss of mobility Dependence on others Acute or chronic pain General health status Life-threatening! terminal disease Poverty Social isolation Loneliness Mental state - e.g. depression Bereavement Difficulty sleeping Boredom Inability to perform activities of daily living Loss of ability to make decisions Lack of control
the validity and reliability of the questionnaire for a wide variety of clinical situations. The SF-36 assessment tool is available free of charge from the UK Clearing House for Information on the Assessment of Health Outcomes, Nuffield Institute for Health Service Studies (see References for web site address). More informal assessment of the quality of life of the elderly can be achieved through normal clinical conversation. The practitioner, as part of a normal discussion with the patient, can gain a fair idea of the patient's quality of life. Podiatry is a profession which is well suited to this task, since patients are often seated for treatment for 20 min or so, and treatment does not usually prevent the patient from talking. Patient and podiatrist are usually sitting face to face, and one-to-one communication is established. Where a podiatrist is concerned that the patient has a poor quality of life, or feels that the patient is unusually sad or depressed, a more formal assessment of quality of life can be undertaken. This may involve a referral to other members of the health and social care team: e.g. health visitor, social worker or general practitioner (GP).
Assessment of cognitive status Assessment of cognitive function in the elderly can be important for all health care workers.
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This is particularly important where a practitioner seeks informed consent from a patient for a clinical procedure. Those changes most frequently associated with the ageing process are forgetfulness and confusion. Forgetfulness is a behaviour which affects all people, young or old. The fact that elderly people appear to forget things more often may be related to several factors. First, people who are old today received a different education to people who are young today. Some elderly people will have received a very basic education, had poor schooling and, as a result, may appear less intelligent and more forgetful. Coupled with this is the fact that most elderly people had limited exposure to the media when they were young compared with young people today who are exposed to a mass media. This cohort effect is probably an important factor in explaining why elderly people have difficulty remembering certain facts, recalling events and handling complex ideas. It is important to remember that forgetfulness is not necessarily indicative of the onset of brain disease or dementia. Dementia is another cause of forgetfulness. It is a relatively common finding in elderly people. Dementia can arise as a result of reductions in supply to the brain of oxygen, nutrients or hormones. Dementia is not a single disease, but a term used to encompass a variety of brain diseases. The most common causes of dementia in the elderly are Alzheimer's disease and multiinfarct dementia (recurrent mini-strokes of cortical/subcortical areas). Confusion is where an individual has difficulty placing herself in terms of time and/or place. It can lead to disorientation, loss of short-term memory, changed levels of activity, speech defects, hallucinations and clouding of consciousness. Acute confusion (delirium) is a relatively common finding amongst elderly people. It may also be an important indicator of an underlying systemic disease (e.g. CVA, infection). Confusion may be aggravated by drugs (e.g. alcohol), sight or hearing defects and presence of other brain diseases (e.g. Parkinson's disease). Confusion may also be a feature of acute or chronic dementia.
Table 18.10
Mental test score
1_ Name 2. Date of birth 3. Age 4. Date and time of day 5. Address 6. Name of prime minister 7. Date of First World War 8. Place 9. Remember an address 5 min later 10. Count backwards from 20 to 1
Assessment of mental state can easily be achieved by means of a mental test score (Table 18.10). This is performed by the practitioner asking 10 simple questions to the patient. A low score (less than 7) indicates confusion and warrants referral to other agencies (e.g. GP, psychiatrist). Deterioration in mental test score may indicate the presence of a chronic dementing illness (e.g. Alzheimer's disease).
Assessment of ability to perform basic foot care For the practitioner, accurate determination of an elderly patient's ability to perform basic tasks relating to foot care will be important. The following activities are important as part of personal activities of daily living: • • • • • • •
cutting and/ or filing of toe nails filing of hard skin application of cream to the sole of the foot washing and drying of feet putting on stockings, tights or socks putting on and fastening shoes change of a dressing applied to the foot (where appropriate) • inspection of feet for lesions.
Inability to perform the above activities may place an elderly person at greater risk of deteriorating foot health. This is particularly likely where the elderly person is not able (or eligible) to receive podiatric care and where there is an assumption that the person will manage her own feet. Failure to perform these basic activities may ultimately also contribute to deterioration in
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mobility, independence and quality of life. For example, patients may feel less inclined to go outside of the house if putting on shoes and hosiery becomes difficult. Provision of simple aids, such as elasticated laces and stocking helpers, can sometimes rectify this problem, by providing assistance with difficult activities. Inability to check and clean feet can be a major risk for deterioration in foot health status. This is especially true for patients with either peripheral vascular insufficiency or defects of sensory perception. Sight defects may compound the problem. In these cases, the patient should be encouraged to ask a carer to check their feet regularly, or seek regular professional assessment. The best way to assess an individual's ability to perform basic foot care tasks is to observe them being performed. Practitioners should spend some time with patients looking for signs of difficulty reaching feet, putting on shoes and hosiery, and problems with manual dexterity (e.g. arthritis of fingers). This can often be determined during the course of a normal consultation:
those people most at risk. Usually, notions of risk have centred on medical need for foot care. It is clearly a worthy desire to focus limited resources on those most at need. However, risk assessment of the elderly can be a hazardous pursuit and should not be undertaken without appropriate validation of risk assessment protocols. The risks of prioritisation are enormous, both to individuals and to health services. Getting it wrong has major consequences for individuals (ulceration, infection, falls, gangrene, amputation) and for health services (litigation, complaints, costs of managing complications, effect on other service providers, etc.). Generally, the elderly can be divided into three groups in respect of risk status: high risk, medium risk and low risk (Table 18.11). What Table 18.11
RISK ASSESSMENT AND THE ELDERLY Limited resources for public podiatry services have resulted in attempts to prioritise services to
Definitions of elderly risk groups
High risk
Patients with systemic pathology presenting a risk to foot health (e.g. diabetes mellitus, Cushing's disease, leukaemia, anaemia, etc.) Patients with existing foot ulceration or other loss of lower limb tissue viability Patients who have a history of falls Patients with peripheral vascular disease Patients with peripheral neuropathy Patients with hip joint pathology or prosthesis Patients who are bed-ridden Malnourished patients Patients taking certain medications (steroids, anticoagulants, anticancer drugs, etc.) Patients with severe cognitive impairment Patients unable to self-care with poor carer support Infirm or frail people living alone Poor patients Socially isolated patients
Medium risk
Patients with poor skin quality or skin disease Patients with thickened nails Patients with calluses or corns Patients with toe deformities Immobile patients Patients with superficial fungal infections of skin or nail Patients unable to self-care with adequate carer support
Low risk
Patients with mild foot pathology Patients with good circulatory status Patients with good neurological status Independent patients or those receiving good levels of home care Mobile patients Patients with good personal care/hygiene
• Is the patient able to take off and put back on her own shoes and hosiery? • Can the patient touch areas of her feet? • Is the patient able to manipulate a pair of scissors / nippers? • Can the patient manage the use of a file? • Can the patient apply a cream to the foot? • Is the patient able to change a dressing on her foot? It is important for the practitioner observing these skills to bear in mind that conditions in the patient's own home may be totally different to those in the clinical environment. Patients may find it easy to manage their feet while seated in a podiatry chair, but find the same tasks difficult in an armchair or on a sofa or bed.
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becomes clear when looking at these definitions is that most podiatry departments are already focusing on those at greatest risk. Several providers of foot health services have attempted to use risk 'scoring' methods to make decisions on eligibility for podiatry services. These criteria are often rigidly applied, allow no professional discretion and are sometimes administered by people other than those specialised in the assessment of the lower limb. Where risk assessment protocols are used, it is important for practitioners using such protocols to be able to obtain second opinions, and identify patients who they feel are at risk but who do not fit the 'rigid' criteria. Risk assessment of the elderly is further complicated by the fact that elderly people tend to deteriorate much faster than young people. An elderly person who seems quite fit today may be infirm or ill tomorrow. This effect can have devastating consequences for foot health where a patient is under the impression that they are no longer eligible for foot care. Reassessment of the elderly patient is necessary at regular intervals. Risk status changes with corresponding changes in general health status, physiological changes and social circumstances. Even changes in time of the year can have a profound effect on risk status. For example, during the summer a patient may appear to have adequate peripheral circulation, but the same patient might assess as high risk during the winter when circulation deteriorates. The most effective risk assessment protocols have used qualitative descriptors of risk rather than rigid/quantitative risk-scoring mechanisms. Effective risk assessment is dependent upon the following:
• • • •
existence of a valid risk assessment protocol patient understanding of the process compliance of the patient with advice availability and motivation of carers (where appropriate) • awareness of CPs (and others) of the protocols / eligibility for re-referral • ability to reassess/review risk status as required.
Even the most effective risk assessment protocol fails from time to time and patients who were identified as low risk may develop serious pathology. Where risk assessment does fail, departments need to ensure that patients can receive rapid assessment and treatment to prevent the likelihood of significant adverse consequences. It is impossible to be completely certain when assessing the risk of individuals, particularly the old. Health providers need to weigh up the costs (personal, social and economic) of risk assessment with the costs of universal provision of podiatry services.
SUMMARY This chapter has examined a range of factors that are pertinent to the assessment of the elderly. Although the overall assessment process for the elderly should be no different to that of any other age group there are specific factors that should be taken into consideration. It is essential that practitioners are aware that any assessment of the elderly provides a snap shot of the elderly person at the time of the assessment. In view of the ageing process and increased risk of acquiring a range of diseases the status of the elderly person may change from low to high risk within a relatively short period of time.
REFERENCES Bennett G C J, Ebrahim S 1995 health care in old age, 2nd edn. Arnold, London Clearing House's web site: (http://www.leeds.ac .uk Inuffield I infoservices IUKCH I home.html) Crawford V L S, Ashford R L, McPeake B, Stout R W 1995 Conservative podiatric medicine and disability in elderly
people. Journal of the American Podiatric Medical Association 85(5): 255-259 Hansard 1998. HMSO, London Harvey I, Frankel S, Marks R, Shalom 0, Morgan M 1997 Foot morbidity and exposure to chiropody: population based study. British Medical Journal 315: 1054-1055
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Mahoney F I, Barthel D W 1965 Functional evaluation: the Barthel Index. Maryland State Medical Journal 14: 61-65 Plummer E S, Albert S G A 1996 Focused assessment of foot care in older adults. Journal of the American Geriatrics Society 44: 310-313 Turner W A, Campbell J A, Milns D et al 2000 Prevalence of foot problems amongst the elderly. Society of
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Chiropodists & Podiatrists Annual Conference, Commonwealth Institute, London, May 2000 Turner W A, Campbell J A, Milns D 2001 The cruelest cut? Effects of podiatric discharge on 5000 'low risk' elderly people over two years. Podiatry, People & Politics Conference, University College, Northampton,S April 2001 Wei J Y 1992 Age and the cardiovascular system. New England Journal of Medicine 327(24): 1735-1739
CHAPTER CONTENTS
Introduction
469
Preoperative assessment 470 The systems enquiry 473 Factors affecting operative risk 478 Laboratory investigationsand imaging modaHties Postoperative assessment
481
480
Pre- and postoperative assessment 1. Reilly
Summary 482
INTRODUCTION Corrective surgery can provide a resolution to many chronic foot conditions that have traditionally been treated by conservative care, e.g. ingrown toe nails, hammer toes, hallux abductovalgus. The majority of surgical procedures on the foot performed by podiatrists in the UK are undertaken on an elective basis under local or regional anaesthesia rather than general anaesthesia. This chapter focuses on the assessment of patients having surgery under local anaesthesia. Many texts assume preoperative assessment means surgery to be performed under general anaesthesia. Such texts may state that, for example, the insulin-controlled diabetic patient is not fit for day surgery. However, as long as the insulin-diabetic patient has been appropriately assessed and there are no major contraindications it is possible to undertake surgery under local anaesthesia on an outpatient basis. Moreover, early and effective intervention in the diabetic could prevent later amputational and salvage surgery. The process of surgery can be broken down into three distinct phases: the pre-, intra- and postoperative phases. These phases are collectively known as the perioperative period and may overlap and vary in relative importance, depending on the individual patient and the nature of the planned surgical procedure. The overall results of surgery depend upon the effective assessment and management of each phase. Table 19.1 identifies the key issues in the assessment process. 469
470
SPECIFIC CLIENT GROUPS
Table 19.1
The preoperative assessment process
Diagnosis • Information from the primary patient assessment • What is the diagnosis? • What are the important facets of the history? • What further investigations are required? Fitness for surgery • Is the patient fit for surgery? • Are there any concomitant diseases that increase the perioperative risk? • Is the patient on any drugs that could influence the surgical outcome? The anaesthetic • Local anaesthetic (or general anaesthetic) • Which technique will be used? The operation • What is the surgical plan? • Does the surgery itself pose any special problems? • Has informed consent been obtained? After the operation • Can any problems be anticipated? • Have redressing appointments been arranged?
PREOPERATIVE ASSESSMENT Clear communication between the practitioner and the patient is vital and forms the basis of informed consent, which is a prerequisite to any invasive procedure. The decision to recommend surgery to the patient is taken in light of the presenting problem after non-surgical treatment options have been tried (or at least considered) and when the potential risks and benefits of invasive techniques have been calculated in the surgeon's mind. It is the responsibility of the practitioner to determine the most likely diagnosis of the problem based on a detailed history taking and physical examination. Appropriate laboratory investigations and diagnostic imaging support and confirm the provisional diagnosis. The purpose of the preoperative assessment
The purpose of the preoperative assessment is to: • review the history of the presenting illness or complaint • review the major systems of the body and ascertain whether these systems are
functioning within normal limits and, if not, to facilitate the management of this • arrive at an informed position regarding the medical appropriateness of the planned surgical procedure • identify any factors that may contraindicate surgery or place the patient 'at risk'. At the end of the assessment the practitioner will have an opinion in his mind as to whether the patient is fit for surgery. This will allow the practitioner to proceed knowing that the risk of encountering an intra- or postoperative complication has been reduced to a minimum. An inadequate assessment of the patient's health status may have serious consequences for the surgical patient. The patient is placed at risk. Inappropriate or unsafe surgery is performed because of inadequate knowledge of the patient's medical history. Surgery carried out on patients with certain systemic pathologies carries an increased risk of postoperative morbidity. Medical disorders can complicate surgical practice in various ways: e.g. a patient with rheumatoid arthritis on steroid therapy is prone to impaired healing and infection. An occult condition may manifest under the stress of surgery: e.g. a cerebrovascular insult may occur intraoperatively in patients with undiagnosed hypertension. Invasive treatment on haemophiliacs or patients taking anticoagulant therapy requires special consideration because of the likelihood of very slow blood clotting and haemorrhage. The use of postoperative analgesia, especially if obtained on group protocol, requires that the practitioner is familiar with the indications, contraindications, interactions and side effects of the analgesic medication. The surgeon is placed at risk. The practitioner will inevitably encounter blood and tissue fluids on a regular basis. Inadequate history taking with regard to identifying known or potential blood-borne diseases such as hepatitis B places the practitioner and his assistants at risk. An increased risk of clinical emergencies. A number of intraoperative emergencies, such as hypertensive crises, can arise. A detailed preoperative assessment should identify those at greatest risk.
PRE- AND POSTOPERATIVE ASSESSMENT
Poor treatment outcomes. A combination of any of the above factors can lead to a poor treatment outcome. Without judicious use of laboratory investigations, certain disease states can be overlooked. Assessment of preoperative radiographs are essential if the practitioner is to effectively plan the appropriate surgical procedure. A systematic approach to the assessment process will ensure that the practitioner covers all relevant areas in the enquiry process. The use of questionnaires give the patient time to ~on sider his answers, reduces the amount of time spent during the consultation and ensures that the patient answers relate to their current and past health status (Ch. 5). Health status can be classified using the American Society of Anesthesiologists' (ASA) scale (Table 19.2). Patients who fall into either Class 1 or 2 will be the most suitable for elective procedures. . .. As already noted in the introduction It IS assumed that the practitioner undertakes a full medical and social history as detailed in Chapter 5. There are specific issues that need to be taken into consideration when assessing a patient for elective surgery under local anaesthesia. These are considered below.
Table 19.2 American Society of Anesthesiologists' (ASA) surgical risk classification
Class
Symptoms
Class 1
The patient has no organic, physiological, biochemical or psychiatric disturbance. The pathological process for which the operation. is to be performed is localised and does not entail systemic disturbance
Class 2
Mild to moderate systemic disturbance caused either by the condition to be treated surgically or by other pathophysiological processes
Class 3
Severe systemic disturbance or disease from whatever cause, even though it may not be possible to define the degree of disability with finality
Class 4
Severe systemic disorders that are already life threatening, not always correctable by operation
Class 5
The moribund patient who has little chance of survival but is submitted to operation in desperation
471
Current health status Body mass. Obesity is a condition that may be more complicated than simple overeating. Obesity is associated with various endocrine disease, type 2 diabetes mellitus, peripheral vascular disease, hypertension and cardiac disease, anaemia, deep vein thrombosis (OVT), cholecystitis and nutritional imbalances. Obese patients have an increased risk of postoperative OVT and wound complications such as infection and dehiscence. It is commonly assumed that malnutrition is rare in Western societies. However, the malnutrition status among the elderly is alarmingly high. A percentage weight loss of 20% or greater is associated with a lO-fold increase in operative mortality following major surgery, and a threefold increase in postoperative infection. Vitamin BI (thiamine) and B deficiencies are associated with peripheral neuro~athy. Vitamin C and serum zinc deficiencies may impair wound healing. Seriously underweight patients may be suffering from a range of systemic conditions or they could be poorly nou:ished due to alcoholism, drug abuse or anorexia nervosa. Fatigue and weight changes are symptoms of many systemic illnesses and are always worthy of note, especially if weight change appears to be rapid. General health. In general, patients who are unwell are not good candidates for surgical procedures or treatments which are likely to demand close compliance on their behalf. Pregnancy. Rarely will elective surgery be indicated on a pregnant woman.
Past and current medication
Information about the patient's past and current drug therapy can provide useful information about the patient's health status. Patients should be asked if they are currently taking, or have taken in the past, any tablets or medicine or used any ointments or creams that have been prescribed by their doctor or bought over-thecounter. The practitioner should refer to the British National Formulary (BNF) or other pharmacological text if unfa~iliar with any drugs the patient is taking. In particular, details of adverse
472
SPECIFIC CLIENT GROUPS
reactions, either by the patient or any member of the patient's family, to previous local anaesthetic injections and other drugs (e.g. penicillin) should be sought and explored. Steroids such as prednisolone are commonly used in the treatment of asthma, obstructive airway disease and rheumatoid arthritis. They have three main effects, which can be of importance during the perioperative period: • suppression of the hypothalamus/pituitary adrenal (HPA) axis • poor wound healing • a predisposition to infection. There will be a suppression of the HPA if the patient has taken more than 7.5 mg/ day of prednisolone for more than 1 week. In such instances, consideration must be given to the administration of exogenous steroids to prevent hypotension or cardiovascular collapse. For minor procedures a typical regimen would be 15 mg PO (by mouth) at 6 a.m. on the day of surgery; and the same dose 12 and 24 hours later. Anticoagulants are used in ischaemic heart disease, mitral stenosis, atrial fibrillation and in the prevention of postoperative thrombosis formation. Heparin inhibits the intrinsic clotting pathway and is used in the short-term prophylaxis of DVT. Warfarin inhibits the extrinsic clotting pathway and is used in long-term therapy. The use of an oral anticoagulant has obvious implications if surgical treatment is planned (Case history 19.1). Adjustment of the dosing regimen can be undertaken by the patient's Case history 19.1 A 54-year-old lady presented with an interdigital corn that has failed to respond to many years of palliative treatment. The history and physical examination revealed that she suffered from atrial fibrillation for which she took warfarin (to prevent ventricular thrombosis). Outcome: surgery was indicated for the patient. At first assessment her INR was 4.1. In consultation with her general practitioner, her dosage was adjusted to reduce the INR to below 2.5. Surgery was carried out with the INR 1.9 on the day. The postoperative course was unremarkable and the patient was discharged after the 12-week follow-up visit.
general practitioner (GP) to allow surgery to proceed with relative safety. Drugs that alter platelet function include aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), steroids and antihistamines. With patients who regularly take aspirin it may be necessary to cease its use because of delayed clotting after surgery. If aspirin use is to be stopped, with the consent of the patient's GP, in order for surgery to proceed, it should be done so 1 week before surgery. It should be noted that women who take oral contraception carry a slightly increased risk of postoperative DVT formation. The use of all recreational drugs should be recorded. Patients who use injectable drugs are at a higher risk of hepatitis and human immunodeficiency virus (HIV). Long-term or heavy use of tobacco can affect wound healing due to the immediate vasoconstrictive effect of nicotine as well as the long-term effect of increased platelet adhesiveness and atherosclerosis. Tobacco smokers are also at greater risk of bronchitis, asthma and lung cancer. Heavy alcohol consumption can affect peripheral sensation, immune response, postoperative healing and the metabolism of local anaesthetics, as well as having implications for treatment compliance. Past medical history
The past medical history consists of information about previous lower limb problems and the treatment received, as well as details about any problems that have affected the patient's general health. The nature of previous treatment, the name of the practitioner, details of relevant investigations such as X-rays and the patient's view of the treatment success should be recorded. This information may prevent the repetition of tests or treatments which have previously been ineffective. Of particular interest is the operative history of the patient. In an audit of an NHS surgical caseload, 10% of patients were referred for revisionary surgical intervention. Home circumstances It is important to assess the patient's home situation. In the case of surgical treatment, the prac-
PRE- AND POSTOPERATIVE ASSESSMENT
titioner must establish who is going to transport the patient to and from surgery and who is going to assist her through the immediate postoperative recovery period. Lack of home support may rule out surgical intervention (Case history 19.2). ~------------------·---l
I
Case history 19.2
I
A 59-year-old widow was referred for treatment for a tailor's bunion. Palliative treatment did not control the symptoms. A preoperative assessment was undertaken with a view to performing a metatarsal osteotomy of the fifth metatarsal head. The patient lived alone and had no children. The only home support the patient was able to organise was from neighbours. This support was not very reliable as the neighbours were out at work all day. Outcome: the typical postoperative course is to rest completely for 2 days and to be on 'light duties' for between 2 and 4 weeks. Patients are asked not to perform any household duties and to have someone to stay with them for the first 2 days in case an emergency should arise. In view of the lack of home support, surgery was not offered to the patient.
Occupation
A patient's occupation may be a contributory cause of the lower limb problem and may influence whether surgery could or should be offered. Some patients may experience particular difficulties in taking time off from work to attend for treatment and need to be aware of the variable amount of time needed to recuperate from surgery (Case history 19.3). The patient who cannot or will not devote the time to heal after surgery is not a good surgical candidate. Sports and hobbies
Details of any sporting hobby should be sought from the patient. As indicated in Case history 19.3, the patient needs to devote time to postoperative healing, and therefore cessation of sporting activity must be emphasised to the patient. Foreign travel
Details of foreign travel should be recorded in case the patient has acquired an unusual foot
473
\-------------------------,
I
Case history 19.3
!
A 47-year-old publican attended for a surgical opinion. He suffered from a complex digital deformity and the preoperative assessment indicated that he required extensive digital and soft tissue reconstruction. While discussing his occupation as a landlord, the patient expressed his intention to return to bar work the evening followinq surgery. He equated the surgery he was to receive as akin to that of a tooth extraction under local anaesthesia from a dentist. Clear (and written) advice was given regarding the need to rest in the postoperative period. Outcome: the patient did not comply with the advice given. He presented at his first redressing appointment with marked forefoot swelling and pain more than would have been expected from the procedure performed. The final result was a less than satisfactory 'sausage toe', through a failure to take appropriate advice. This example highlights the need to document the advice given to patients during the perioperative period to protect the surgeon from litigious action.
infection. In particular, travel to tropical countries and any foot injuries sustained while walking barefoot should be recorded. Many countries have a higher incidence of HIV than the UK. A history of blood product transfusion abroad could, therefore, be important.
The systems enquiry The cardiovascular system
A history of cardiovascular disease should be taken with respect to systemic, peripheral and haematological disease states, followed up by a review of symptomatology. Patients with ischaemic heart disease (IHD) may present with a history of previous myocardial infarction (M!), stable or unstable angina or a history of previous coronary artery bypass graft (CABG). A detailed history must be taken of all patients who have suffered previous cardiac problems or have high-risk factors such as obesity, hypertension, shortness of breath on exercise, smoking or a family history of cardiac problems. Ten percent of patients over 50 years old presenting for non-cardiac surgery had previously suffered MI. This is
474
SPECIFIC CLIENT GROUPS
significant because there is a known risk of reinfarction in the perioperative period. The relative significance of that risk is dependent on the time elapsed since the first MI. A quarter of patients presenting for non-cardiac surgery are likely to have another MI if less than 3 months has passed since their first attack. However, if more than 6 months is allowed to elapse, the incidence of repeat MI falls to less than 5 in every 100 patients. Angina may be classified as stable or unstable. Stable angina takes the form of chronic, predictable, exertional chest pain. In these circumstances, when there is no history of a previous MI, and other risk factors are absent, the risk of perioperative MI is low provided that the patient is not exposed to any excessive stress. The patient's anti-anginal medication should be continued perioperatively. An assessment needs to be taken of how the patient will respond to having surgery under local anaesthesia - in other words, while the patient is awake. Some patients may find this very stressful and, therefore, would be considered unsuitable. Unstable angina is characterised by increased frequency, severity and duration of painful attacks that is not easily controlled by their medication. Angina of recent onset, angina at rest or with minimal exertion or angina awakening the patient from sleep should also be considered unstable. Such unstable angina symptoms carry the same perioperative risk as having had an MI in the previous 6 months. Surgery is contraindicated until the angina has been stabilised by medical or surgical means. A history of CABG should also be taken into consideration. In essence, these patients have had their symptoms controlled by surgery but they may still have limited cardiac reserve and may not be able to respond well to the additional stress of surgery. Patients in congestive heart failure (CHF) have diminished cardiac reserve and do not respond well to perioperative stress. CHF carries a high perioperative risk of MI in patients undergoing general anaesthetic and therefore elective surgery must be avoided in patients presenting with third heart sounds, an elevated
jugular venous pulse or pulmonary oedema. As patients who undergo procedures under local anaesthesia frequently experience considerable stress from fear and apprehension, those in cardiac failure represent a high risk of an adverse perioperative cardiac event. Conduction defects represent a low risk in elective foot surgery under local anaesthesia; however, the opinion of the general practitioner and anaesthetist is useful. Patients with a history of fainting attacks may require specific assessment before any elective surgery under local or general anaesthesia. Patients will often offer a history of palpitations, 'missed heart beats' or fainting attacks. Any patient who gives a history suggestive of an arrhythmia should have an electrocardiogram (ECG) that can then be carefully assessed by a cardiologist prior to local anaesthesia. Major heart valve disease is becoming rarer but a heart murmur is still a regular finding in routine medical examinations. Most murmurs are related to turbulent flow of blood in the heart and are not significant and do not represent heart valve damage. A history of valvular heart disease is of concern because it carries a risk of bacterial endocarditis, CHF and MI. The American Heart Association recommendation for cases with mitral valve prolapse and a detectable murmur is that antibiotic prophylaxis should be prescribed in all procedures where a transient bacteraemia is created. In the main, bone surgery on the foot is clean and prophylaxis is not required. Antibiotic prophylaxis is, however, required in nail surgery where there is paronychia or in any incision and drainage procedures of infected tissue. Well-managed, mild to moderate hypertension poses no increased perioperative risk, although in all cases hypertensive medication should be continued perioperatively. Treated hypertension is associated with ischaemic heart disease and stroke. In cases of uncontrolled hypertension, the patient may present with a variety of symptoms, including headaches, transient visual impairment, anorexia or even nausea. Two very significant findings are impaired renal function manifesting clinically as proteinuria and/or
PRE- AND POSTOPERATIVE ASSESSMENT
retinopathy. All patients who have blood pressures above 160/95 on more than one occasion should be investigated and treated prior to surgery. Diastolic pressures greater than 120 mmHg are of grave concern and contraindicate any surgical intervention; they require urgent medical referral. A comprehensive literature review regarding perioperative considerations of the patient with cardiovascular disease has been performed by a member of the Trent Region Podiatric Forum, and is presented in Table 19.3. Anaemia represents a reduction in the oxygencarrying capacity of the blood. Since there are multiple causes and types of anaemia, preoperative consultation is appropriate. Both cardiopulmonary integrity and wound healing are dependent on tissue oxygen levels. Anaemia is rarely a contraindication to surgery unless it is of a severe magnitude. Haematocrit values below 30 are considered insufficient for elective foot surgery.
Table 19.3 Surgical recommendations for the cardiovascular patient (information included with thanks to Dr T Kilmartin of the Trent Forum) Myocardial infarctions (MI)
Surgery should be avoided in patients who have had an MI within the previous 6 months
Angina
In stable angina, where there is no history of an MI or other risk factors, the perioperative risk of an MI is low. In unstable angina, surgery is contraindicated until the angina has been controlled by medical or surgical means
Coronary artery bypass graft (CABG)
A history of a CABG should be considered a low perioperative risk
Congestive heart failure (CHF)
Patients in CHF represent a high risk of adverse cardiac events from the stress of surgery
Conduction disturbances
Conduction defects represent a low perioperative risk
Arrhythmia
Any patient with a history suggestive of arrhythmia should have an ECG performed
Valvular heart disease
Prophylactic antibiosis is not required in clean podiatric surgery to prevent bacterial endocarditis. It is, however, required in nail surgery
Hypertension
Elective surgery is contraindicated in uncontrolled hypertension
475
Haemophiliacs and other patients with clotting abnormalities require thorough history taking. Enquire about bruising, nose bleeds and any previous surgical problems. Further studies that will be indicated include a platelet count and bleeding time. Sickle-cell disease affects those of African or West Indian descent. It is an autosomally inherited haemoglobinopathy resulting in the formation of haemoglobin S (HbS) instead of HbA. Small changes in oxygen tension cause HbS to polymerise and form pseudocrystalline structures, which distort red blood cells into the characteristic sickle shapes. Sickle cells increase blood viscosity and obstruct microvascular blood flow, leading to thrombosis and infarction. A comprehensive literature review regarding the use of tourniquets in this condition has been undertaken by a member of the Trent Region Podiatric Forum, and is presented in Figure 19.1. For a surgical wound to heal uneventfully, adequate peripheral circulation is a prerequisite. Assessment of the vascular status of the lower limb is covered under physical examination, and in detail in Chapter 6. The respiratory system
Postoperative morbidity and mortality from atelectasis and infection are significantly increased in individuals with pulmonary disease, whether anaesthesia is local or general. These effects are most often noted in those individuals with known pulmonary risk factors, such as a history of heavy smoking, pre-existing pulmonary disease, obesity and in the elderly. The preoperative goal is to identify pulmonary risk factors and request an expert opinion as indicated. Preoperative management by consultants may include pulmonary function testing. Smokers should discontinue at least 1 week prior to surgery. The alimentary system
Gastrointestinal (GD disorders are common and have many implications for the lower limb and its treatment.
476
SPECIFIC CLIENT GROUPS
New Patient Afro-caribbean Asian Mediterranean Have you been screened or tested for sickle-cell disease?
Arrange appointment with sickle-cell service for screening and issue of risk card
8------.. . .~,'-------..,...Inform patient of risks and complications
Consider alternative care: • orthotics • clinopody • referral on Surgery without tourniquet
Figure 19.1 Forum).
Tourniquet as necessary Examination of the foot prior to inflation of the tourniquet
Decision-making algorithm for patients with sickle-cell anaemia (with thanks to Mr C Bicknell of the Trent
Patients with severe liver damage may be metabolically unstable and may be unable to withstand the stress and the demands of surgery. Liver cirrhosis is not uncommon and should be identified in the history. Chronic alcoholism may cause osteoporosis, complicate anaesthesia (the metabolism of), increase bleeding risk, decrease wound healing, increase the risk of infection and diminish adrenocortical responses to stress. Serious coexisting nutritional imbalances are often noted.
The genitourinary system The kidneys regulate the body's electrolyte and fluid balance; this has implications for lower limb circulation and oedema and can delay wound healing. The presence of any renal symptoms such as haematuria, dysuria, polyuria, oliguria or flank pain mandates a specific evaluation. Although the perioperative risks for patients with renal disease are primarily related to disturbances of fluid and electrolyte balance, hypertension and oedema may be related to renal dysfunction.
PRE- AND POSTOPERATIVE ASSESSMENT
Confirmation of kidney disease requires specific investigation. Screening urinalysis remains the classic measurement of renal performance (Ch. 13). Abnormal findings include the presence of glucose, protein, ketones, bilirubin, more than four red or white blood cells per field, bacteria, casts and crystals. Surgery should be postponed until renal function is stabilised. The central and peripheral nervous system
Diseases of the nervous system may cause pain in the lower limb, deformity or gait abnormalities. The significance of some symptoms in the neurological enquiry will be very difficult to interpret because the enquiry relies on the patient's subjective account. However, inadequate assessment of the neurological basis of foot pathology can lead to inappropriate surgical intervention through a missed diagnosis. A detailed assessment of the peripheral nervous system can be found in Chapter 7. Endocrine system
Diabetes, thyroid disease, growth disorders, obesity and problems associated with the menopause are particularly relevant. Diabetes mellitus is a complex systemic disease that may manifest as vascular, neurological, dermatological and structural changes in the foot and lower leg. The perioperative goal is to reduce hypo- or hyperglycaemia. In the normal subject, hyperglycaemia activates insulin production, but in the diabetic this feedback control loop is defective. Surgical stress causes a catabolic reaction, resulting in glucagon, adrenaline (epinephrine) and cortisol secretion. Blood glucose levels rise and other fuel pathways are mobilised. The practitioner should ensure that a good metabolic balance is obtained preoperatively. Avoidance of the extremes of hypoglycaemia or hyperglycaemia will help optimise wound healing and host defence function. Hyperglycaemia impairs wound healing by retarding wound closure, delaying wound contraction, slowing collagen synthesis, impairing granulocytes and
477
reducing red blood cell viscosity. Elective surgery should be avoided in diabetic patients with blood sugar values greater than 200 mg/dI. Chronic hyperglycaemia greatly increases the risk of postoperative infection. The use of haemoglobin AlC, an index of hyperglycaemia, is helpful in evaluating trends in diabetic control. Inadequate nutrition and reduced total plasma albumin have been shown to deter wound healing in patients with diabetes and should be normalised preoperatively when possible. Diabetics with a propensity towards ketosis require intraoperative intravenous insulin and monitoring. Wide blood sugar variations are associated with unpredictable healing ability and an increased surgical risk. A patient who is taking multiple medications is more prone to drug interactions, which may also affect diabetes management. General anaesthesia creates a greater perioperative risk because of increased insulin demands, the risk of silent MI, nausea and vomiting, and delays in food and oral medication intake. Earlymorning surgery allows the optimal equilibrium between insulin dose and caloric intake, with immediate oral nutrition postoperatively. The locomotor system
To determine the presence of musculoskeletal disease the patient should be asked if they have ever had: • • • • • •
any form of arthritis back, hip, knee, ankle or foot pain fractured bones in the legs or feet pulled or injured muscles in the legs joint swelling or stiffness limb pain during any specific activity.
Arthritic patients may be considered to include persons with single-joint osteoarthrosis and those with more complex multiorgan arthritides, including rheumatoid arthritis, systemic lupus erythematosus (SLE) and seronegative arthritis. Osteoarthrosis. There are no specific perioperative considerations for the management of the osteoarthritic patient. However, the patient may be on a range of analgesic and anti-inflammatory preparations, which must be considered in the
478
SPECIFIC CLIENT GROUPS
overall assessment of the patient. NSAIDs alter bleeding times and some authors recommend their cessation. Rheumatoid arthritis. Many patients coming to surgery have been on long-term steroids. These drugs suppress the HPA axis, and patients may require corticosteroid coverage during the perioperative period. This should be given even if it has been 1 year since the patient has received medication (it is not necessary to treat a patient with steroids if they have only received intraarticular injections of cortisone). Disease-remittive drugs, e.g. methotrexate, suppress the bone marrow and can cause leucopenia and thrombocytopenia, increasing the likelihood of infection. They can safely be stopped for several days during the perioperative period, in consultation with the prescribing doctor. Systemic lupus erythematosus (SLE). Since SLE is a multisystem disease, a careful history and assessment should be performed prior to surgery. If the patient has received corticosteroids within the last year prior to surgery, consideration should be given to stress-coverage replacement during the perioperative period. Raynaud's phenomenon is also associated with this disease and constitutes a contraindication to the use of adrenaline (epinephrine) in foot surgery and may affect wound healing. Seronegative spondyloarthropathies. If possible, elective foot surgery should be performed during periods between active disease flare-ups. Otherwise, there are no specific perioperative considerations for Reiter's syndrome, psoriatic arthritis or enteropathic arthritis. Gout. Any patient with a history of gout is at a substantially increased risk of a postoperative gouty attack. This may be due to local surgical trauma, dehydration and the temporary interruption of uricosuric medication. Those at highest risk have had an attack within the last year or are on hyperuricaemic medication. Septic arthritis. Septic arthritis is a serious condition. The patient is likely to be generally unwell and should not undergo surgery if there is any chance the joint is infected. Synovial fluid analysis should be considered where there is a recent history of infection.
Physical examination
The format of the physical examination is summarised in Table 19.4. The aim of the physical examination is to identify abnormality and delineate those patients who are fit for surgery. Opinions vary as to the level of the examination required for the patient undergoing elective surgery under local anaesthesia. The practitioner is expected to have undertaken a detailed physical assessment involving the systems (Ch. 5), peripheral vascular status (Ch. 6), peripheral neurological status (Ch. 7), orthopaedic status (Ch. 8) and skin (Ch. 9). As the physical examination has been considered in these chapters, it will not be dealt with in this chapter.
Factors affecting operative risk The use of local anaesthetics
Local anaesthetic agents can be defined as drugs which are used clinically to produce a reversible loss of sensation in a circumscribed area of the Table 19.4
Physical examination
The cardiovascular system • Blood pressure • Ankle brachial pressure index (ABPI) • Temperature • Palpation of pulses • Capillary refilling time (CRT) • Oedema The respiratory system • Shortness of breath (SOB) • Observe for clubbing of fingers The alimentary system • Rarely performed The genitourinary system • Midstream urinalysis reagent testing The central nervous system • Gait • The motor system • The sensory system The endocrine system • Blood glucose monitoring for diabetics The locomotor system • Joint range and quality of motion • NCSP/RCSP • Arch profile • Digital position
PRE· AND POSTOPERATIVE ASSESSMENT
body. Because surgical techniques require their use, any contraindication to local anaesthetics must be identified. The following contraindications should be considered: Unstable epilepsy. High blood levels of local anaesthetic agents are known to cause convulsions in some epileptic patients through their action on brain tissue. Their use is therefore best avoided in such individuals. Methaemoglobinaemia. Methaemoglobin is a form of haemoglobin consisting of globin with an oxidised haem-containing ferric iron. Methaemoglobin is unable to transport oxygen and therefore compromises cardiovascular function. When prilocaine is metabolised by the liver, small amounts of a chemical called O-toluidine are produced which inhibits the enzyme involved in the conversion of methaemoglobin to haemoglobin. In patients with known methaemoglobinaemia, an alternative local anaesthetic agent to prilocaine should be utilised. Pregnancy and breastfeeding. The British Medical Association suggests that drugs should only be used during pregnancy where the potential benefit outweighs the risk of harm to the fetus, particularly during the first trimester where all drugs should be avoided if possible. There is no specific guidance on the risks associated with the low doses of local anaesthesia used in the foot of a pregnant woman. However, because of the ability of local anaesthetics to cross the placental barrier, they are probably best avoided whenever possible during pregnancy. If a local anaesthetic were to be given during pregnancy it would seem prudent to avoid prilocaine hydrochloride, as fetal haemoglobin is more susceptible to the development of methaemoglobinaemia. Both lidocaine (lignocaine) and bupivacaine are considered safe for use with breastfeeding mothers, as the quantities secreted into breast milk are small. Porphyrias. The porphyrias are a group of metabolic disorders. Included in the list of drugs contraindicated for use in patients with porphyria are some local anaesthetics. These drugs must therefore be avoided in known carriers of the porphyrogenic gene to avoid precipitating an acute attack.
479
Where surgery is still indicated, the use of a general anaesthetic should be considered and the patient referred. Psychiatric status
Patients approach surgery with an understandable amount of fear and anxiety. They know that they will be in an unfamiliar environment to which they are unaccustomed. Some fear that they will experience pain during the operation. Most of their anxiety is down to inadequate knowledge based on hearsay and rumour. During the preoperative assessment it is important that the practitioner recognises the hypernervous patient and provides appropriate information and counselling to allay any concerns. However, it is important that the practitioner recognises when a patient is unsuitable for surgery under local anaesthesia and, if surgery is necessary, refers the patient for general anaesthesia. Age Older patients. An increasing percentage of the population is over 65 years of age, a trend that is expected to continue well into the 21st century. Independent ambulation is an important component of wellness, although a majority of patients over the age of 65 complain of foot pain limiting their activity. In geriatric patients who have foot conditions which can be surgically corrected, and where the physical condition is satisfactory, surgery can safely be performed. The chronological age of the patient is less important, as long as the physiological age of the patient is adequate for the planned surgical procedure. The problems of surgery on the older patient include:
• an adverse physiological status • impact of surgery on the patient's lifestyle • selection of the operative procedure - simple procedures versus complex procedures - even though the latter would give a better result. Generally, in the older patient, it is found that destructive rather than functionally reconstructive procedures are often more appropriate.
480
SPECIFIC CLIENT GROUPS
-------------------------------------------------------------------------------------------Children. Attention to the child's psychology, patient-parent relationships and stress levels is important in the surgical treatment of the paediatric patient. Parental presence during the operation may be beneficial.
Infection
In general, the elective procedure is performed when the patient is free from all systemic infection. A patient with established infection that does not respond to oral antibiotics and appropriate wound care demands a thorough preoperative evaluation and specialty consultation.
Laboratory investigations and imaging modalities Urine testing. As indicated in Chapter 13, urinalysis is an aid in the diagnosis of renal disease, hepatic disease and diabetes mellitus. Diabetes mellitus can have widespread consequences for the lower limb and is of particular interest to the surgeon. Renal and hepatic diseases may have serious systemic repercussions and, if identified, require further investigation before it is safe to proceed with surgery. Urinalysis is therefore useful in the preoperative assessment of patients to screen for illnesses which may complicate or contraindicate elective procedures. Screening for a urinary tract infection (UTI) or the presence of bacteria in urine can also identify those patients at increased risk of developing postoperative wound infections. Testing is non-invasive and cost-effective, and urine specimens are easily obtained. Blood analysis. The use of blood analysis in the preoperative assessment of the surgical patient is a matter for debate. Routine screening prior to surgery is likely to reveal a small percentage of abnormality, most of which is insignificant to anaesthetic or surgical management in any case. Therefore, the general rule for the use of confirmatory diagnostic testing should apply: their use is indicated from the initial patient assessment. In cases where systemic pathology is known or suspected - e.g. in anaemia to ascertain
haemoglobin levels - blood sampling is most certainly indicated. The patient on anticoagulant therapy has already been discussed. Similarly, patients who suffer from clotting abnormalities also require further investigation (Table 19.5). Radiographs. Radiographs are vital to the surgeon for a number of reasons: • they allow the identification of many rheumatological, metabolic, endocrine and infective disease states • they allow the progression of deformity to be monitored • they show the precise relationship between osseous anatomical structures that are of particular interest to the surgeon • they aid in the selection of the most appropriate surgical technique • they demonstrate the position of retained internal fixation and are used to confirm bone healing in the postoperative phase. The identification and use of angular relationships, or charting, between the foot bones has become a key skill of the podiatrist. Osteoporosis begins in middle life and is predominantly a disease of postmenopausal women. Histologically, bone formation is normal, but bone resorption is increased. If preoperative radiographs suggest significant osteoporosis, systemic disease is likely and multiple contributing factors, including dietary deficiencies, endocrine imbalances, sedentary lifestyles and genetic predisposition, may be implicated. The implications for the fixation of osteotomies are clear. Radiographic assessment is covered in Chapter 11.
Table 19.5
Common clotting abnormalities
von Willebrand's disease Haemophilia Type A - classical haemophilia Type B -Christmas disease Type C - PTA (plasma thromboplastin antecedent) deficiency Vitamin K deficiency
PRE- AND POSTOPERATIVE ASSESSMENT
POSTOPERATIVE ASSESSMENT The postoperative phase is said to have begun when the patient leaves the operating theatre. However, wound healing commences with the initial surgical incision. The wound will progress through the phases of inflammation to establish environmental homeostasis amenable to tissue repair. Careful preoperative assessment and meticulous surgical technique will assist the wound through this process and minimise postoperative complications. A surgical complication is an unexpected set of circumstances which occurs during the perioperative setting that directly or indirectly prolongs the patient's functional recovery period. Complications are inherent to all types of surgical procedures and forefoot surgery is no exception. If appropriately anticipated, some complications are preventable, whereas the effect of other complications can be minimised with early diagnosis. There must, therefore, be an awareness of the signs of impending complications to trigger prompt and decisive action appropriate to the situation. Management is aimed at avoiding haematoma formation, excess oedema and infection while attempting to keep the patient comfortable and protect the surgical site. The format of the postoperative assessment involves the following: • evaluation of the wound dressing • evaluation of the wound • evaluation of pain. Evaluation of the wound dressing
A wound dressing has several functions: the main goal is to provide an optimum environment for healing to take place. It must first protect the wound from contamination and prevent the overgrowth or penetration of pathogens. It must be absorptive and draw the fluids away from the wound and prevent their accumulation - this will reduce tissue maceration. Differing materials can be employed to provide temporary immobilisation, with or without compression as required. This places a wound at rest and allows healing to take place
481
without undue mechanical forces impeding the physiological processes. Clots and newly formed capillaries are thus not disturbed and pain levels are decreased. Gentle compression will aid haemostasis and prevent the formation of haematoma. Immobilisation is particularly important in reconstructive surgery to maintain the foot or a digit in its corrected position during the healing process. The postoperative dressing regimen typically sees the first dressing change at 4-7 days after surgery. The inspection of the dressing is part of the overall assessment process. Ensure that there are no overt signs of slippage, which may predispose exposure of the wound to contamination. If compression has been applied, has it been effective? Examine the inside of the dressing to gauge both the amount of blood loss and the nature of any exudate formed. A bacterial infection will demonstrate purulent, offensive exudate and require prompt antimicrobial therapy and lor drainage. It is important to record normal and abnormal findings throughout the healing process. Suture removal is typically at 10-14 days postoperatively. The dressing is inspected as before, and all points noted. Evaluation of the wound
A classification of wounds can be found in Table 19.6. The majority of bone procedures on the foot are classified as clean, with the exception of nail surgery, where it is impossible to disinfect the invaginated nail sulci to the same standard as unbroken skin. Table 19.6
Wound classification
Wounds can be classified as: • Clean: surgical incisions are made with no break in aseptic technique; no known contamination and no Inflammation IS encountered • Clean-contaminated: a minor break is made in aseptic technique • Contaminated: a major break is made in aseptic technique, or in a fresh traumatic wound (less than 4 hours) • Dirty: acute bacterial infection encountered with or without pus. A traumatic wound with delayed treatment (greater than 4 hours). A retained foreign body or infected surgery
482
SPECIFIC CLIENT GROUPS
When examining the wound postoperatively, the surgeon is expecting to see: • an intact wound that shows no sign of dehiscence • a 'normal' amount of inflammation • no sign of excessive bleeding, oedema or haematoma formation • the position maintained if any reconstructive technique has been performed. Meticulous suturing technique combined with anatomical dissection, adequate haernostasis and careful skin handling are important to reduce the incidence of these complications. When the sutures are removed it is important to check the healing of the wound edges by gently applying tensile force across the area. Dehiscence will require further support of the wound until the area has regained its mechanical strength. Evaluation of pain
The degree and severity of pain in the postoperative period depends on: • the physiological and psychological make-up of the patient and his tolerance of pain • the site and nature of the operation • the amount of surgical trauma. Pain reflects not only tissue injury but also represents a psychological dimension to suffering. Much unnecessary suffering may be avoided by the reduction of preoperative anxiety. Simple, clear and honest communication with the patient should include an explanation of what will happen and when it will happen, and can have a positive influence on postoperative pain levels. Certain patients may benefit from prescription of an anxiolytic, used
alone, or with analgesic medications to raise pain thresholds postsurgically. Injections of a long-acting local anaesthetic immediately after surgery are commonly performed and will delay postoperative pain for some time. Combinations of opioid analgesics and NSAIDs, however, provide the mainstay of postoperative pain management. Paracetamol may be combined with opioid analgesics, such as codeine, to gain enhanced analgesia. while NSAIDs may be added to an opioid regimen to provide additional anti-inflammatory and intrinsic analgesic effects. During the postoperative period, the patient should be asked about pain levels and details of their responses recorded. There are several tools available to assess pain, including visual analogue scoring and complex questionnaires such as the McGill Pain Questionnaire (Ch. 3). The use of (or lack of) prescribed analgesic medication should also be discussed. The most common causes of excessive postoperative pain in the first week after surgery are excessive swelling within a restrictive dressing or cast and haematoma formation. Extreme levels of pain occurring in the second postoperative week, 'returning pain', are suggestive of infection. A suspicion of haematoma formation or infection requires prompt intervention and management.
SUMMARY The continuum of surgical care encompasses the pre-, intra- and postoperative phases. Careful attention to detail during each phase is essential for the achievement of a successful surgical outcome. The approach outlined in this chapter will ensure that a broad range of factors are taken into consideration when assessing the pre- and postoperative patient.
FURTHER READING British National Formulary (BNFl Updated twice yearly. British Medical Association and Royal Pharmaceutical Society of Great Britain, London Forrest A P M et al 1995 Principles and practice of surgery, 3rd edn. Churchill Livingstone, Edinburgh
Greenberger N, Hinthorn D 1993 History taking and physical examination: essentials and clinical correlates. Mosby Year-Book, St Louis McGlamry E D 1992 A comprehensive textbook of foot surgery. Williams & Wilkins, Baltimore
PRE- AND POSTOPERATIVE ASSESSMENT
O'Higgins N J et al1991 Surgical management, 2nd edn. Butterworth-Heinemann, Oxford Pinnock C et al1999 Fundamentals of anaesthesia. Greenwich Medical Media, London Seymour C, Siklos P 1994 Clinical clerking: a short introduction to clinical skills, 2nd edn. Press Syndicate of the University of Cambridge
483
Tally N, O'Connor S 1989 Clinical examination. Blackwell Scientific, Oxford Turner R, Blackwood R 1991 Lecture notes on history taking and examination, 2nd edn. Blackwell Science, Oxford Zier B 1990 Essentials of internal medicine in clinical podiatry. W B Saunders, Philadelphia
Index
A A-beta fibres, testing, 140-142 A-delta fibres, testing, 142-143 Abbreviations, clinical, 9, 22 Abdominal pain, 68 Abduction, 158, 160, 161 Abductor strength test, 180 Abscess, 223 Brodie's, 287 Accelerometers, 313 Accessory ossicles, 281, 282, 407-408 Accuracy, 42 ACE inhibitors, 60, 90 Acetylcholine, 122 Achilles (ankle tendon) reflex, 144, 145,347 Achilles tendon (tendo calcaneus) rupture, 187, 193,413 Achilles tendonitis (tendinosis), 378, 412-413 Acquired conditions, 7 Acrocyanosis, 369 Acromegaly, 74,440 case history, 71 facial appearance, 59 skin changes, 225, 240 Action potential, 124-125, 126 Activated partial thromboplastin time (APTT), 332, 334 Activities of daily living (ADU, 461, 462,464-465 Addison's disease, 73,440 Adduction, 158, 160, 161 Adductor strength test, 180 Adductovarus fifth, 206 Adrenal gland disorders, 73 Adrenocortical insufficiency, 73, 440 Aetiology, 7 Afferent nerves (nerve fibres), 120-121,122,126-127 large-diameter, testing, 140-142 small-diameter, testing, 142-143 Age at-risk foot, 434 limping in children and, 367 neurological disorders and, 135
perioperative risk and, 479-480 sports injury risk and, 376-377 Ageing, 451 definitions, 453 lower limb consequences, 453-455 skin, 220, 454,457 sweating and, 227 see also Elderly AIDS/HI\', 70, 135,446 Albers-Schonberg disease, 285 Alcohol abuse (alcoholism), 61 drug metabolism, 68 neurological disorders, 135,446 preoperative assessment, 476 consumption, 61, 472 Alignment, structural nonweightbearing assessment, 197-202 sports injuries and, 378-379 X-ray assessment, 276-282 Alimentary system, 67-68 preoperative assessment, 475-476 Allen's test, 100 Allergic contact dermatitis, 228, 235-236, Plate 19 Allergies, 235-236 drug, 61, 236 patch testing, 228 shoe components, 253 Allis test, 207 Alopecia, 225 Altitude, high, 387 Amenorrhoea, in athletes, 377-378 American Society of Anesthesiologists (ASA) surgical risk classification, 471 Amputation at-risk foot, see At-risk foot histology of resected parts, 337 phantom limb sensation, 139 Anabolic steroids, 388-389 Anaemia, 66, 89, 444 diagnosis, 91-92, 95 elderly, 459-460 folate-deficiency, 460
iron deficiency, 92, 225, 460 pernicious, 89, 444, 460 preoperative assessment, 475 Anaesthesia, 139, 155 Analgesics, postoperative, 482 Anaphylaxis, 61 Anchor sign, 350 Aneurysms, arterial, 101 Angina pectoris, 64 surgical risk, 473-474, 475 symptoms, 65,90-91 Angiography in arterial insufficiency, 105 in neurological disorders, 137 venous (venography), 110, 392 Angiotensin-converting enzyme (ACE) inhibitors, 60, 90 Anhidrosis (lack of sweating), 153,227 Ankle children, 352 dorsiflexors, 194 equinus, 171, 188 evertors. 194 examination, 187-194 footballers, 385, 404-405 impingement, posterior, 377 injuries, 190-191 instability, 171 inverters, 193-194 ligamentous injuries, grading, 190-191 motion, 171 muscles, 193-194 plantarflexors, 193 sprain, chronic, 413-414 stress tests, 188-190 tendon (Achilles) reflex, 144, 145, 347 X-rays, 191,273-274 see also Subtalar joint; Talocrural joint Ankle-brachial pressure index (ABPI), 39,103-104,439 Ankylosing spondylitis, 445 Anterior, 158 Anterior cruciate ligament, 166, 184
485
486
INDEX
Anterior superior iliac spine (ASIS), 207,208 Anterior talofibular ligament (ATFL), 189,190 Anti-hypertensive drugs, 90 Antibiotics, 321 prophylactic, 474 sensitivity testing, 326, 327 Anticoagulant therapy, 60, 472 Anxiety, preoperative, 479 Aorta, 80, 81, 88 Apgar score, 345 Aphasia, 155 Aplasia, congenital, 281 Apley's compression test, 185 Appearance, physical, 20 Application letters/forms, 22 Apprehension test, 183 Arch height, 201, 362 index (Staheli), 362 longitudinal, 204 Arm extensors, weak, 155 swing, 168-170, 348 Arrhythmias, 64, 92 surgical risk, 474, 475 Arterial emboli, 96 Arterial insufficiency, 95-106 seealso Ischaemia; Peripheral vascular disease Arterial tree, 81 Arteries, 81, 83 ageing changes, 456 aneurysms, 101 bruits, 102 calcification, 103, 285, 442 Miinckeberg's sclerosis, 103,442 Arteriography, 105, 392 Arterioles, 81, 83, 88 Arteriovenous (A-V) anastomoses, 82-83 Arthritis crystal, 420-421 degenerative, see Osteoarthritis enteropathic, 445 gonococcal, 70 juvenile idiopathic (JIA), 367, 368, 369 preoperative assessment, 477-478 psoriatic, 234, 445 rheumatoid, see Rheumatoid arthritis septic (infectious, pyogenic), 422, 446,478 sero-negative, 445, 478 Arthritis Impact Measurement Scales (AIMS),401 Aspirin, 60 Assessment, 3-10 components, 4, 8 interview,4,11-26 loop, 8 process, 4-7
purpose, 3-4 records, 8-9 repeat, 7-8 risk,4-5 time management, 7 Asthma, 66-67 Astrocytes, 115 At-risk foot, 5, 427-448 assessment, see Risk assessment causal factors, 428-429 clinical decision-making, 447-448 elderly, 455 Ataxia, 114, 151, 175 Atenolol, 93 Atherosclerosis, 95-96 coronary, 90 in diabetes, 442 Atopic eczema (dermatitis), 221, 232-233 Atrioventricular (AV) node, 87 Atrophie blanche, 107-108, Plate 5 Atrophy muscle, see Muscle, atrophy skin, 223 soft tissue, 98 subcutaneous fat layer, 239 Auspitz sign, 222, 231 Autoimmune disease, 288-289 Autonomic nervous system (ANS), 87-88,122-124 assessment of function, 153 Autonomic neuropathy, 153,441 Axon, 115, 116 Axonal degeneration, 149 Axonotmesis, 139
B Babinski response (plantar reflex), 145, 146,347 Back pain, low, 424 Bacteria, 320 bone and joint infection, 287 culture, 228, 323-325 identification, 324, 325-327 microscopy, 323 skin infection, 237-238, Plate 21 in urine, 330-331 Balance, 133 Ball tread, 249 Ballottement test, 183 Barefoot walking, 255, 260 Barlow's test, 353 Baroreceptor reflex, 88, 153 Barthel index, 462 Basal cell carcinoma, 243 Basal ganglia, 117, 130 dysfunction, 151 Beau's lines, 224, 225 Behcet's disease, 445 Beighton scale, 352, 379 Bendrofluazide, 60 Beta-blockers, 60, 90, 93 Bias errors, 48
Bilirubin, urinary, 329 Biochemistry, blood, 334-335 Biomechanics, 308 Biopsy, 336-337 excisional. 337 muscle, 150 needle, 337 nerve, 144, 150 punch (incisional), 336-337 shave,336 skin, 228 Biothesiometer, 142 Bleeding time, 332, 334 Blistering disorders, 231-232 Blisters, 223, 231-232, 439 Blood,331 analysis, 331-335, 480 biochemistry, 334-335 components, 331 coughing up, 67 count, full, 95, 332-333 film, 333 sample collection, 332 serology, 335 in urine (haematuria), 69, 330 Blood gases, arterial, 334 Blood pressure, 64, 93-94 in autonomic dysfunction, 153 elderly, 456 measurement, 93-94 regulation, 88 seealso Hypertension Blood urea nitrogen (BUN), 334 Blood vessels anatomy, 81-84 major, 80 physiology, 88-89 skin, 218 Blount's disease, 355 Body mass index (BM!), 381 Body weight (mass), 59-60 loss, 72 preoperative assessment, 471 Bone cyst aneurysmal, 293 solitary (simple), 292-293 density, 282-285 infection, 287, 288, 422 isotope scanning, 298-300, 392 metastatic disease, 285, 296 tumours, 292-296 Bone marrow, MRI imaging, 296, 298, 299 Boots, 253-254 Bottoming, 250 Bow legs, see Genu varum Bowel habit, altered, 68 Bowen's disease, 242-243 Brachydactyly, 281, 282 Brachymetatarsia, 201 Bradycardia, 92 Brain anatomy, 117, 118
INDEX 487
ascending pathways, 127, 128 descending pathways, 127, 129 scans, 137 Brain stem, 117, 118, 128 Breastfeeding, 479 Breathlessness (dyspnoea), 65, 67, 91 Brodie's abscess, 287 Bromhidrosis, 227 Bronchitis, chronic, 66, 67 Brown-Sequard syndrome, 138-139 Bruits, 102 Budiman-Mak Foot Function Index, 34 Buerger's disease (thromboangiitis obliterans), 96, 438 Buerger's elevation/dependency test, 100 Bulla, 222, 223 Bullous pemphigoid, 232, Plate 15 Bundle of His, 87 Bunion, tailor's, 205 Burrow, 222 Bursae, calcification, 285-286 Bursitis, retrocalcaneal, 418-419 Buschke's disease, 290
c C fibres, testing, 142-143 C-reactive protein (CRP), 332, 333 Cadence, 307 Calcaneal stance position neutral (NCSP), 202-204 relaxed (RCSP), 202-204 Calcaneocuboid fault, 280 Calcaneofibular ligament (CFL), 190 Calcaneonavicular coalition, 363, 409 Calcaneus bone density, 283 deformity, 161 fractures, 291, 298 inclination angle, 279-280, 352 position, 171 spurs, 280 Calcification, degenerative, 285-286 Calcinosis cutis, 287 Calcium antagonists, 60,90 Calibration, instrument, 45-46 Callus, 229-231, 439 elderly, 458 periungual, 226 Caltrac device, 316 Candida spp., 327 Capillaries, 81, 82-83 fluid flow, 86 function, 89 skin, 218 Capillaroscopy, 105 Capillary filling time (CFT), 100 Carbon dioxide, blood, 335 Cardiac output, 87 Cardiovascular disease clinical tests, 92-94 current medication, 90 exercise cautions, 382
history, 64-66, 90 hospital tests, 94-96 observable signs, 92, 225 symptoms, 90-92 see also Heart disease; Hypertension; Peripheral vascular disease; Venous insufficiency Cardiovascular system (CVS), 80-89 anatomy, 80-86 at-risk foot, 438-439 elderly, 455-456 general overview, 90-95 physiology, 86-89 preoperative assessment, 473-475 Carpal tunnel syndrome, 143 Cartilage, 285 Casts, urinary, 330 Catalase test, 326 Cauda equina, 121 Cellulitis, 237-238, 422, 448, Plate 37 Central nervous system (CNS), 70-71 anatomy, 116-119 in posture/balance/ coordination, 133 see also Neurological disorders Cerebellum anatomy, 117, 118 dysfunction, 150-151, 152 function, 129-130 Cerebral cortex, 117, 118 Cerebral palsy, 348 Cerebral vascular accident (CVA, stroke), 114, 128,446 loss of consciousness, 136, 137 risk factors, 135 upper motor neurone lesions, 146 Cerebrospinal fluid (CSF), 115, 118-119 Champagne legs, 109 Charcot foot, 299, 403, 441-442, Plate 34 Charcot-Marie-Tooth disease, see Hereditary motor and sensory neuropathy Cheiroarthropathy, 443 Chemicals, in shoes, 253 Chest pain, 65, 67, 90-91 Chest X-ray, 95 Chilblains, 235, 369 Children, 341-369 assessment, 343-353 generalapproach,343-344 initiating, 343 conditions affecting lower limb, 353-369 examination, 346-352 footwear, 258, 352-353 gait analysis, 59, 348, 367 history taking, 344--346 interviewing, 344 limping, 365-368 non-weightbearing assessment, 350-352 normal development, 342-343 perioperative risk, 480
sports injury risk, 376-377 weightbearing assessment, 348-350 Chloramphenicol, 60 Chloride, plasma, 335 Chondrocalcinosis, 288 Chondromalacia patellae, 183 Chondromatosis, synovial, 293 Chondrosarcoma, 294--295, 411 Chopart's joint, see Midtarsal joint Choreo-athetotic movements, 151, 155 Chromonychia, 224, 225, 226 Cine photography, 314 Cinema seat sign, 354 Circulation collateral, 83-84 peripheral (systemic), see Peripheral vascular system pulmonary, 81, 89 Circumduction test, 178 Clarke's test, 183 Claudication distance, 97, 103 intermittent, 97 Claw toe, 172,206 Clinical environment, 45, 51-52 Clinical examination, 4 Clinical measurement, see Measurement Clinical tests, 4 Clogs, 254, 255 Clostridium welchii, 325 Closure,24 Clothing, 49 practitioners, 20 in sports assessment, 375-376 Clotting abnormalities, 480 tests, 332, 333-334 Clubbing, 92,224,225 Clubfoot, 360 one-third of, 358 Coalitions, 187,281-282 tarsal, see Tarsal coalitions Codrnan's triangle, 294 Cognitive status, assessment, 461, 463-464 Colchicine, 60 Cold-related sports injuries, 387 Collagen, 377 Collar (sports shoe), 248 Collaterals, 83-84 Colour nail, 225, 226 skin, see Skin, colour urine, 328-329 wound,437 Coma, 137 Common peroneal nerve, 119 Communication, 12-21 listening skills, 15-16 non-verbal, 16-21 questioning skills, 13-15 Compartment syndrome, 414-415 chronic, 391, 414-415
488
INDEX
Compensation, 163 Computed tomography (CT), 296, 297, 298 in neurological disorders, 137 quantitative (QCT), 283 in sports injuries, 392 Concerns, patients', 15,29 Conduction disturbances, 474, 475 Confidentiality, 9-10, 25 Confusion, 464 Congenital conditions, 7 Congenital talipes equinovarus, 360 Connective tissue disorders, 446 Consciousness assessment of level of, 136-138 loss of, 135, 136 Constipation, 68 Contact dermatitis, 221 allergic, 228, 235-236, Plate 19 Contraceptive pill, 60 Conversation, 11-12 Coordination, 133 assessment, 150-152 causes of poor, 150 Corns, 229-231, 439, Plate 12 elderly, 458 fibrous, 231 hard, 231, Plate 13 periungual, 226 seed,230 soft, 231 vascular, 231 Coronal plane, see Frontal plane Coronary angiography, 95 Coronary arterial disease (CAD), 90 Coronary arteries, 84 Coronary artery bypass graft (CABG), 473,474,475 Corticospinal tract, 129 Corticosteroids, seeSteroid therapy Cortisol deficiency, 73 Corunebacterium minuiissimum, 325 Cough.ri? Court shoe, 254, 255 Coxa valgum, 170 Coxa vara, 170 Coxodynia (hip pain), 175, 176 CRAGCEL acronym, 59, 64 Cramps, nocturnal, 65-66, 97-98 Cranial arteritis, 70 Cranial nerve palsies, 155 Cranial nerves, 120 Creatinine, serum, 334 Crepitus, 165 Crohn's disease, 445 Crossed extensor reflex, 132 Cruciate ligaments, 184 Crusting, 222, 223 Crystal arthritis, 420--421 Crystals, in urine, 330 CT, see Computed tomography Cuboideum secundarium, 281 Culture media, 323-325 Cushing's syndrome, 73, 284, 440
Cyanosis, 6, 92 in venous insufficiency, 107 Cyclic AMP, 125 Cyma line, 280 Cyst, 222 bone, 292-293 D Darier's disease, 229 Data gathering, 24 intervals, 39 nominal, 39--40 ordinal,39 ratios, 39 Data Protection Act, 9-10, 25 Deep peroneal nerve, 119 entrapment, 416--417 Deep venous thrombosis (DVT), 106-107,109 Deformity, terminology, 161 Delivery, 345 Dementia, 464 Demyelination, segmental, 149 Dendrites, 115, 116 Dental disease, 67---68 Dermal papillae, 217 Dermatitis chronic, 229 contact, see Contact dermatitis herpetiformis, 219, 232 juvenile plantar, 236, 368-369 seealso Eczema Dermatofibroma, 242 Dermatoglyphics, 218-219 Dermatology, 213 Dermatome, 121 Dermatomyositis, 147,240,446 Dermis, 215, 218 Dermo-epidermal junction (DEJ), 216, 217 Desmosomes, 216,217 Development foot, 343 milestones, 345-346 normal childhood, 342-343 Diabetes insipidus, 72 Diabetes mellitus, 440, 441--444 autonomic neuropathy, 153, 441 elderly, 456, 459 exercise in, 383 foot ulcers, 428 classification systems, 432--433 ischaemic, 442, Plates 35-36 neuropathic, 441, Plates 32-33 risk assessment, 433--447 history, 71-72 insulin-dependent, 225 microangiopathy, 442 motor function testing, 149 nervous system involvement, 154 perioperative risk, 477 peripheral neuropathy, 417, 441--442
sensory testing, 141, 142, 143 shoe wear marks, 264 skin changes, 240 X-rays, 285 Diagnosis, 5-7 differential, 6 Dialect, 21 Diaphyseal dysplasia, 285 Diarrhoea, 68 Diastole, 87 Dichrotic notch, 103 Differential diagnosis, 6 Digital formulae, 206 Digiti quinti varus, 205 Direction of motion (DOM), 164, 165 Disabled Living Foundation (DLF), 261,265 Disease, coexisting at-risk foot, 435 elderly, 454--455 skin disease, 239-240 sports injuries, 382-383 Dislocation, 165 Distal, 158 Distal articular set angle (DASA), 278, 279 Diuretics, 90 Doppler ultrasound, 300 in arterial insufficiency, 102-103, 104-105 in neurological disorders, 137 sources of error, 50, 51-52 in venous insufficiency, 102, 109 Dorsal, 158 Dorsal columns, 128 Dorsal horn, 120 Dorsalis pedis artery patency testing, 100 pulse, 51-52, 100, 101 Dorsiflexion, 158, 159 Dorsiflexors, 194 Drawer test, 184, 189,414 Dressings, wound, 481 Drugs adverse reactions, 60, 61, 236 allergies, 61, 236 eruptions, 236 first-pass metabolism, 68 history, 60-61 metabolism, 68 preoperative assessment, 471--472 recreational, 61, 472 self-prescribed,61 sports injuries and, 388-389 Dual energy X-ray absorptiometry (DEXA),283 Dual-photon absorptiometry (DPA), 283 Dupuytren's contracture, 443 Dysarthria, 151, 155 Dysdiadochokinesia, 151, 155 Dysphagia, 68 Dyspnoea (breathlessness), 65, 67, 91 Dystrophia rnyotonica, 147 Dysuria, 69
INDEX 489
-------------------------------------------------------_._-----E Eating disorders, 378 Eburnation, 283 Ecchymosis, 222 Eccrine poroma, 242 Echocardiography, 95 Ecthyma, 237 Eczema, 59,232-233 asteatotic, 233 atopic, 221, 232-233 discoid, 233 distribution, 220 gravitational (stasis, venous), 108, 233, Plate 6 seealso Dermatitis Edmonds and Foster diabetic foot staging system, 433 Education, patient, 434 Efferent neurones, 120-121, 122 Ehlers-Danlos syndrome, 240 Eight-finger test, 187 Elastic stockings, 107 Elbow golfer's, 385 tennis, 385 Elderly, 451-466 assessment, 455-465 definition, 453 functional assessment, 461-462 malnutrition, 471 perioperative risk, 479 population, 452 risk assessment, 465-466 seealso Ageing Electrocardiogram (ECG), 95 Electroencephalogram (BEG), 137 Electrogoniometers, 313-314 Electromagnetic tracking systems, 315 Electromyography (EMG), 149, 315 Electron beam tomography, 95 Ely's test, 178 Emboli arterial, 96 venous, 107 Emed system, 312 Empathy, 14 Emphysema, 66, 67,461 Enchondroma, 292, 411-412 Enchondromatosis, multiple, 292, 294 Endocardium, 81 Endocrine disease, 71-74 at-risk foot, 440-444 elderly, 459 perioperative risk, 477 Endothelium, vascular, 81 Energy expenditure, 315-316 Enteropathic arthritis, 445 Environmental factors at-risk foot, 434 sports injuries, 387 Ependymal cells, 115 Ephelis, 240 Epidermis, 215, 216-217, Plate 9 basal layer, 216
granular layer, 216-217 horny layer, 217 prickle cell layer, 216 Epidermolysis bullosa, 232 Epidermophyton floccosllln, 238, 327 Epilepsy, 136, 137 progressive focal deficit, 155 surgical risk, 479 Epiphyseal dysplasia, 285 Epiphyses, 283, 343 Epithelial cells, in urine, 330 Equinus deformity, 161 Equipment measuring, see Measuring instruments/equipment sporting, 383-384 Erosions, 223 Errors, measurement, 44-51 random, 44 systematic, 45 Erythema, 221,222 multiforme, 235 nodosum,221,239 Erythrasma, 238 Erythrocyanosis, 235, 369 Erythrocyte sedimentation rate (ESR), 332,333 Erythrocytes (red blood cells, RBC), 89 counts/indices, 332-333 microscopy, 333 in urine, 330 Erythroderma, 234
Escherichia coli,325 Ethnic origin, 63 Eversion, 158, 159 Evertors, foot, 194 Ewing's tumour, 295-296, 411 Excoriation, 223 Exercise ankle-brachial pressure index and, 104 claudication distance, 97, 103 surface, 384-385 in systemic disease, 382-383 seealso Sports Exostosis osteocartilagenous, 292 subungual, see Subungual exostosis Extension, 158 Extensor digitorum longus (EDL), 205 Extensor substitution, 205 Extensus deformity, 161 External rotation, 158,160 Extrapyramidal system, 129, 130 Exudation, 222 Eye contact, 17 Eyeballing, 48
F F-Scan insole system, 312-313 Faber's test, 178 Facial appearance, 59
Facial expression, 17, 59 Factor V gene mutation, 106 Fainting, 65, 70, 136,474 Falls, 135 Family history, 62-63, 346 Fasciculi proprii, 128 Fat, subcutaneous, see Subcutaneous fat layer Fatiguability, progressive, 148, 155 Fatigue, 60 Feedback, 26 Female athlete triad, 377-378 Femoral nerve, 119 Femur, length inequality, 207 Fibromas, periungual, 226 Fibrosarcomas,295 Fibula children, 351-352 examination, 186-187 50:50 test, 183 Financial aspects, footwear, 256 Finger-nose test, 152 First-pass metabolism, 68 Fissures, 223, 439, Plate 30 Fitness, physical, 380, 388 Flare, shoe, 249, 259 Flat feet, see Pronation, abnormal! excessive Flexibility, sports injuries and, 377, 378,379-380 Flexion, 158 Flexor hallucis longus tenosynovitis, 412,413 Flexor stabilisation, 204 Flexor substitution, 204 Fluid displacement test, 183 tissue, 86 Fluoroscopy, 300 Fluorosis (fluorine excess), 285 Fog index, 14 Folate-deficiency anaemia, 460 Foot alignment, 197-202, 276-282 anatomical variations, 281-282 arch, see Arch care, ability to perform, 464-465 children, 352 drop, 175 elderly, 453-455 flat, see Pronation, abnormal! excessive growth and development, 343 high-arched cavoid (pes cavus). 173, 262,263 length, 201-202 moccasin, 238 muscle activity, 173 neutral position, 199,201 pain, 397-424 assessment / measurement, 398-403 causes,399,403-424 examination, 398
490
INDEX
Foot (Cont'd) plantar pressure measurement, see Pressure measurement sensors, plantar position/shape, 173 pronated, flat, see Pronation at risk, 5, 427-448 switches, 307 trauma, 291 X-ray views, 271-274 Foot Function Index (FFI), 402 Foot Health Status Questionnaire (FHSQ),402--403 Footballer's ankle, 385, 404-405 Footprints, 43--44, 204 Harris & Beath mat, 309 impressions during gait, 307, 308 ~usgrave,311-312
Footwear, 245-265 acceptance of advice on, 246 acquisition, 256 assessment, 255-265 history taking, 256 purpose, 246 shoe fit, 256-261 wear marks, 261-264 athletes, 248, 383-384 children, 258, 352-353 diabetes mellitus, 442, 443 practitioners, 20 in sports injuries, 376 seealso Hosiery; Shoes Force, 308 plates, 311 sensitive resistors, 311-312 in-shoe measurement, 312-313 Forefoot children, 352 deformity, 171 everted, 201 inverted,199-201 to rearfoot alignment, 199-201 supinatus, 199-201 valgus, 201 varus, true, 199,200-201 Foreign bodies, 292 Forgetfulness, 464 Fractures, 291 classification, 291 healing, 291 march,385 stress, see Stress fractures young athletes, 376 Freckles, 240 Freiberg's disease (infarction), 196, 289-290 Frequency of urination, 69 Friction, athletic surfaces, 384 Friedreich's ataxia, 114 Frontal lobe, 117, 118 Frontal plane, 157, 158 deformity, 161 joint motion, 158, 159 joint position, 161
Frusemide, 60 Functional ability, 453--454 Functional assessment, 461--462 Fungi children, 368 culture, 323-325 identification, 327 microscopy, 228, 323 skin infections, 238, 239, Plate 23 specimen collection, 228, 322 Wood's light examination, 227-228 G Gait abnormal patterns, 173-175 analysis, 163, 167-175, 303-316 children, 59, 348, 367 elderly, 457-458, 462--463 GHORT method, 304 limb-length inequality, 168, 170, 206-207 methods, 304 multisystems, 316 observational (visual), 59, 167-173,304-306 quantitative methods, 306-316 sources of error, 51 in sports injuries, 376 angle and base, 202 antalgic, 173,398,463 apraxic, 155 apropulsive, 173-174,463 ataxic, 151, 155, 175 in cerebellar dysfunction, 151 children, 342 circumducted,175 disorders affecting, 167 dystrophic/ atrophic, 175 electromyography, 315 energy expenditure, 315-316 festinating, 152, 155, 175,463 helicopod, 175 kinematics, 313-315 kinetics, 308-313 mats, 307 in Parkinson's disease, 152 scissor, 145, 175, 176 spatial parameters, 306-308 stance phase, 167-168, 169 steppage, 175, 463 swing phase, 167-168, 173 temporal parameters, 306-308 in-toeing, 170,348,356-360 Trendelenburg, 175, 348 in upper motor neurone lesions, 145 seealso Walking Calleazi's sign, 353 Ganglion, 420 resection, 337 X-ray assessment, 285, 286 Gangrene, 99 dry, 99, Plate 3
wet, 99 Gastric ulcers, 67 Gastritis, 68 Gastrointestinal (GIl disease, 67-68, 475--476 Gender neurological disorders and, 135 sports injuries and, 377-378 seealso Women Genitourinary system, 68-70, 476--477 Genu recurvatum, 351 Genu valgum (knock knees), 161, 170-171 children, 351, 355 non-weightbearing assessment, 197-198 sporting activities and, 377 Genu varum (bow legs), 161, 170-171 children, 351, 354-355 non-weightbearing assessment, 197-198 Gestures, 17-18 Giant cell tumours, 295 Glabellar tap reflex, 152 Glial cells, 115 Glomus body, 83 Glomus tumours, 226, 420 Glucometers, 335 Glucose blood,335 urine, 329 Goniometers, 313-314 finger, 164 gravity, 164, 177, 198-199 Gonococcal arthritis, 70 Gout, 420--421, 445--446 preoperative assessment, 478 X-ray assessment, 286 Gracilis muscle, 180 Graded potential, 125-126 Grading scales, 39 Gram stain, 323, 325 Granuloma annulare, 235 pyogenic, 242, Plate 25 Grasp reflex, 347 Grass, artificial, 384 Grief response, sports injuries, 381-382 'Growing pains', 363 Growth, childhood, 343 Growth hormone excess, see Acromegaly Guillain-Barre syndrome, 114, 134, 154,446 H Haematocrit, 332, 333 Haematological disease, 66, 444, 459--460 Haematology, 332-334 Haematoma,223 Haematuria, 69, 330
INDEX 491
rIaemoglobin, 89,332,333 glycosylated (Crib), 335 indices, 332, 333 Haemophilia, 66, 444, 475 Haemoptysis, 67 Haemorrhages, splinter, 92, 224, 225 Haemosiderosis, 108, Plate 6 Hair follicles, 218 in ischaemia, 98, Plate 1 Hallux abduction angle, 277, 278 abductovalgus. 205, 206 abductus, 205, 206 abductus interphalangeus, 206 dorsiflexion test, 363 extensus (trigger toe), 196, 206 flexus, 196,206 hyperextended, 206 limitus, 196,206 plexus, 406 rigidus, 196, 206, 406-408 valgus juvenile, 364-365 metatarsalgia, 410 sports activities and, 377 varus, 206 rIammer toe, 204, 206 Hamstring nerve, 119 Hamstrings, 185 tightness, children, 350, 355-356, 368 Handshake, initial, 23, 59 Hansen's disease, 446 Harris & Beath mat, 309 rIead position, 168,348 Headache. 70, 135 Healing delayed, 435 fracture, 291 Health status measuring tools, 401-402 preoperative assessment, 471 questionnaire, 22, 59, 77-78 Hearing, 50 rIeart anatomy, 80-81, 82 murmurs, 474 physiology, 87-88 valves, 81, 82 Heart disease, 64--65, 90-95 ischaemic, see Ischaemic heart disease valvular, 474, 475 Heart failure, congestive (CrIF), 64, 89 signs and symptoms, 65, 91 surgical risk, 474, 475 Heart rate, 87, 88, 92-93 in autonomic dysfunction, 153 physiological cost index, 316 Heat loss, 89 rIeel to ball length, 249, 258 'bumps', 418-419 pain, 239 children, 367
shoe, 247, 248 height, 255 wear patterns, 262-263 tab,248 Heel lift, 167, 169 early, 174-175 Heel pad syndrome, 419 Heel-shin test, 152 rIeel-toe test, 152 rIeight,20 Helbing's sign, 192,361 Hemiplegic gait, 145 Heparin, 472 Hepatic disease, see Liver disease Hepatitis B, 69 Hepatitis C, 70 Hereditary conditions, 7 Hereditary motor and sensory neuropathy (rIMSN, Charcot-Marie-Tooth disease), 114,154,421-422,446 case histories, 148, 347 investigations, 149, 422 Herpes simplex, 237 Herpes zoster, 135,237 rIigh altitude, 387 High-density lipoprotein cholesterol (rIDLC),95 High-heeled shoes, 254, 255 Hindfoot, see Rearfoot Hindfoot stabiliser, 248 Hip abduction limitation test, 353 developmental dislocation (DDrI), 345,353-354,367 examination, 175-180 in children, 349, 350-351 in in-toeing child, 357 functional tests, 180 joint, 175-176 motion, 176-178 muscle tests, 178-180 pain, 175, 176 Histology, 335-338 indications, 335-336 sample transportation and storage, 337 sampling techniques, 336-337 skin, 228 tests and interpretation, 338 History taking, 31-33, 57-78 athletes, 387-391 children, 344-346 family history, 62-63, 346 format, 75 medical history, 58-62 personal social history, 63-64 purpose, 57-58 questionnaire, 77-78 systems enquiry, 64-74 trrv/ AIDS, 70, 135,446 Hobbies, 63, 473 Horne circumstances, 63, 472-473 Hosiery, 107, 264-265
Hospital based tests, 4 Hospitalisation, previous, 62 Human papilloma virus (rIPV) infection, 237 Huntington's chorea, 151 Hydrostatic pressure, 86 H yperaemic test, 104 Hypercalcaemia, 72, 440 Hyperglycaemia, 459, 477 Hyperhidrosis, 72, 153, 227 Hyperkeratosis, 222-223, 229-231, 458 Hypcrlipidaemia. 59, 456 Hypermobility, sports injuries and, 379-380 Hyperparathyroidism, 284 Hyperpyrexia, malignant, 147 Hypertension, 64, 93, 94 elderly, 456 exercise in, 382 preoperative assessment, 474-475 see also Blood pressure Hyperthyroidism (thyrotoxicosis), 72, 440-441 facial appearance, 59 osteoporosis, 284 skin changes, 240 Hypervitaminosis 0, 284 Hypo Zbradykinesia, 152, 155 Hypocalcaemia, 72, 440 Hypoparathyroidism, 284 Hypopituitarism, 284 Hypotension, postural, 153 Hypothetico-deductive reasoning, 5 Hypothyroidism, 73, 440 elderly, 459 facial appearance, 59 skin changes, 229, 240 Hysteresis, 45, 310 I Ichthyosis, 229 Idiopathic conditions, 7 Iliopsoas contracture, 178 Iliotibial band contraction/ tightness, 178-180 Illness, coexisting, see Disease, coexisting Imaging techniques, 269-300 preoperative, 480 see also Computed tomography; Magnetic resonance imaging; Ultrasound; X-rays Implants, surgical, 292 In-toeing, 170,348,356-360 Independence,256,461,462 Independent Footwear Retailers Association, 265 Indices, 39 Indomethacin, 60 Infants posture, 342 reflexes, 346, 347
492
INDEX
Infection, 422-423 at-risk foot, 439 bone and joint, 287, 288 children, 368 diabetes mellitus, 442-443 indications for referral, 448 lymphangitis/lymphadenitis, 110-111 microbiology, 320-328 perioperative risk, 480 as presenting problem, 5, 422 signs, 108,422 skin, see Skin, infections tropical, 64 venous ulcers, 108 wound,437-438 Infestations, 238-239 Inflammation blood tests, 333 joint, 164 Inflammatory skin conditions, 232-235 Information booklets/sheets, 22, 23 Infrapatellar fat pad, 182 Injuries, previous, 62 Insect bites, 239 Insole, 247 Insole pressure measurement systems, 312-313 Instruments, measuring, see Measuring instruments/ equipment Intermetatarsal angle, first-second, 364 Intermetatarsal bars, 282 Intermittent claudication, 97 Internal genicular position, 357-358 Internal rotation, 158, 160 International Statistical Classification of Diseases, Injuries and Causes of Death, 9 Interobserver reliability, 43 Interosseous talocalcaneal ligament, 191 Interphalangeal joints (IPJ), 197 distal (DIPJ), 197, 198 examination, 197, 198 proximal (PIPJ), 197, 198 sesamoids, 281 Interpretative model, 5 Intervertebral disc, prolapsed, 424 Interview, 4,11-26 aims, 12,22 children, 344 closure, 24 communication skills, 12-21 documenting, 21-22 practical tips, 25-26 preparation, 22-23 room, 23 stereotyping, 21 structure, 22-25 techniques, 14 versus normal conversation, 11-12 Intracompartmental pressure studies, 392,415
Intraobserver reliability, 43 Inversion, 158, 159 Inverted bottle legs, 109 Invertors, foot, 193-194 Involucrum, 287 Iron-deficiency anaemia, 92, 225, 460 Ischaemia cardinal signs, 104,438-439 clinical tests, 99-104 critical limb, 98, 104 diabetic foot, 442, Plates 35-36 hospital tests, 104-106 indications for referral, 448 observable signs, 98-99, Plates 1-2 symptoms, 97-98 Ischaemic heart disease (IHDl, 64, 90, 473-474 Ischaemic ulcers, 98-99, 442, 443, Plates 35-36 Iselin's disease, 290, 376 Isotope clearance, 105-106 Isotope scanning, bone, 298-300, 392
J Jack's test, 363 Jaundice, 68 Joint ageing, 454 cartilage, 285 disease, 287-289,445-446 see also Arthritis examination, 164-165 inflammation, 164 ligamentous laxity, 352, 379-380 motion, 164-165 direction (DOM), 164, 165 measurement, 164 quality (QOM), 165 range (ROM), 164-165 symmetry (SOM), 165 terminology, 158-161 observation, 164 position, 161 Juvenile idiopathic arthritis (IIA), 367, 368,369 Juvenile plantar dermatitis, 236, 368-369 K Kaposi's sarcoma, 70, 243 Keloid,223 Keratin, 216, 217 Keratinisation, 217 Keratinocytes, 216, 217 Keratoderma climactericum, 229, 459 palmoplantar (PPK), 229, 231, Plate 14 Keratolysis, pitted, 238, Plate 22 Ketones, in urine (ketonuria), 329 Kinematics, 313-315 Kinesics, 17-18 Kistler force plate, 311
Klebsiella spp., 325 Knee bursae, 183 in children, 351 examination, 181-186 functional tests, 186 joint, 181-182 anatomy, 180 motion, 183 painful, 175 stability, 183-185 jumper's, 385 knock, see Genu valgum laboratory tests, 186 muscle testing, 185 observation, 182 pain in children, 354, 367 palpation, 182-183 position, 170-171 Q angle, 186, 354 runners, 385 Koebners phenomenon, 221 Kohler's disease, 290, 367 Koilonychia (nail spooning), 92, 224, 225 Korotkoff sounds, 94 Korsakoff's psychosis, 135 Kyphosis, 349 L Laboratory tests, 4, 319-338 preoperative, 480 Labour,345 Lace-up shoes, 247, 253-254, 260 Lachman's test, 166, 184 Lamellar granules, 216 Langerhans' cells, 216 Language, 14 Larvae migrans, 239 Lasegue's test, 180 Laser-Doppler fluximetry, 106 Lassitude, 91-92 Lasting,250 Lasts, 248-249 Lateral, 158 Lateral collateral ligament stress test, 183 Lateral plantar nerve, first branch entrapment, 416-417 Leather, 252, 253 Leg alignment, see Alignment, structural flexors, weak, 155 fresher's, 385 length inequality, see Limb-length inequality length measurement, 207-208 pain, exercise-induced, 391 shape, venous insufficiency, 109 tennis, 385 torsion, 198-199,202 see also Limb Legg-Calve-Perthes disease, 289, 367 Lentigo, 240
INDEX 493
Leprosy, 446 Lesser tarsus abduction angle, 276-277 Letters, application, 22 Leucocytes (white blood cells, WBC) counts (WCC), 332, 333 microscopy, 333 in urine, 330 Lichen planus, 221, 234-235, Plate 17 nail changes, 225, 234-235 Lichen simplex, 233 Lichenification, 222-223 Ligamentous injuries ankle, 190-191 grading, 393 risk factors, 378, 379-380 Ligamentous laxity, 352, 379-380 Ligaments, 165 Lighting, 45, 48 Limb dominance, 381 motion, 170 see also Leg Limb-length inequality (LU), 175, 206-208 gait changes, 168, 170,206-207 sports injuries and, 379 Limbic system, 117, 128 Limping antalgic gait, 173, 398, 463 in children, 365-368 Linings, shoe, 247,252-253 Lipids, plasma, 95 Listening, 15-16 Liver disease, 67, 68 preoperative assessment, 476 skin changes, 240 Local anaesthetics adverse effects, 61 contraindications, 478-479 postoperative use, 482 Locomotor system, 74 assessment, see Orthopaedic assessment Loose bodies, 288,289 Lordosis, 349 Low-density lipoprotein cholesterol (LDLC),95 Lower motor neurones (LMNs), 129 lesions, 146-150 Lumbar plexus, 119 Lumbar puncture, 138 Lunge test, 190 Lupus erythematosus, 240 systemic (disseminated), 240, 288, 446,478 Lymphadenitis, 110-111 Lymphangiography, 111 Lymphangitis, 110-111 Lymphatics, 84, 85 skin, 218 Lymphoedema, 110-111,229 praecox, 110 secondary, 110, 111 tarda,110
M Macule, 222, 223 Magnetic resonance imaging (MRI), 296-298,299 in arterial insufficiency, 105 in neurological disorders, 137 in sports injuries, 392 Malignant tumours at-risk foot, 439-440 bone, 293-296 foot, 411, 412 internal, skin changes, 240 periungual, 226 skin, 242-243 venous ulcers, 108-109 Malleolar torsion, 198-199 Malleoli children, 351-352 medial, in leg length measurement, 207,208 X-ray assessment, 279 Mallet toe, 206 Malnutrition, 471 Marble bone disease, 285 McArdle's syndrome, 147 McGill Pain Questionnaire (MPQ), 34, 400-401,438 McMurray's test, 184-185 Measurement, 37-52 errors, 44-51 evaluation exercise, 51-52 qualitative, 38-39, 40, 47-48 quantitative, 38, 40-41 selecting technique, 41-42 semi-quantitative, 39-40 standardisation of techniques, 45 terminology, 42-44 types, 38-41 units, 38 Measuring instruments/equipment, 38,41-42 calibration, 45-46 sources of error, 45-47, 49, 50 variation, 43 Mechanoreceptors, 126 Medial, 158 Medial collateral ligament stress test, 183-184 Medial facet tenderness test, 354 Medial plantar nerve entrapment, 416-417 Medial tibial stress syndrome, 391 Medical health questionnaire, 22, 59, 77-78 Medical history, 59-62 current health status, 59-60 medications, 60-61 past, 62, 434, 472 purpose, 57-58 Medical Research Council (MRC) muscle strength grading, 39, 148, 165 Medications, see Drugs Medulla oblongata, 117, 118
Meggit-Wagner wound classification system, 431-432 Melanin, 216 Melanocytes, 216 Melanoma, malignant, 241-242, 440 Meniscus tears, 184-185 Menopause, 459 Mental test score, 464 Merkel's cells, 216 Metabolic disorders, 440 Metaphyseal dysplasia, 285 Metarterioles, 82, 83 Metastasis bone, 285, 296 skin, 243, Plate 26 Metatarsalgia, 410-411 Morton's (neuroma), 58, 411, 417-418 Metatarsals, 171-172 abnormal positions, 196 adduction angle, 277 deformity, 196 examination, 194-196 first (metatarsus primus) adductus angle, 277 assessment of motion, 194-196 elevatus, 195, 196,201 flexible plantarflexed, 196 rigid plantarflexed, 196 formula, 201 fractures, 291 head, prominent fibular condyle, 410 joint motion, 194-196 parabola, 196 protrusion distance, 278 proximal articular set angle (PASA), 278 see also Rays Metatarsocuneiform split, 277 Metatarsophalangeal joints (MTPJ), 196 causing metatarsalgia, 410 first angle, 364 examination, 196, 197 in gait, 172, 173 gout, 421 in hallux valgus, 364 sesamoiditis, 411 motion assessment, 196, 197 sesamoids, see Sesamoids, metatarsal head Metatarsus adductus, 358-360 Metatarsus primus, see Metatarsals, first Methaemoglobinaemia, 479 Metronidazole, 60 Microbiology, 227-228, 320-328 indications, 320 samples (specimens), 320-325 collection, 322 containers, 321-322 examination, 322-325 types, 320-321 Microcirculation, 83 assessment, 105-106
494
INDEX
Microglial cells, 115 Microorganisms identification, 325-328 normally resident, 320 seealso Bacteria; Fungi; Viruses Microscopy blood film, 333 microorganisms, 323 urine, 330 Micturition, abnormal, 69 Midbrain, 117, 118 Midtarsal joint (MTJ), 194 motion, 194 position, 171, 172 Milroy's disease, 110 Minimum bactericidal concentration (MBC), 326 Minimum inhibitory concentration (MIC), 326, 327 Mobility assessment, 461, 462 Moccasin foot, 238 Moccasins,251-252,253-254 Moles, 240-241 Molluscum contagiosum, 237 Miinckeberg's sclerosis, 103,442 Monofilaments, 41, 139 accuracy, 43 using, 141 Mononeuritis multiplex, 134 Mononeuropathy, 134 Moro reflex, 347 Morton's metatarsalgia (neuroma), 58, 411,417-418 Motor cortex, 127, 128, 144 Motor function assessment, 144-150 Motor nerves, 122 Motor neurone disease, 114, 154 Motor neurones, see Lower motor neurones; Upper motor neurones Motor neuropathy, diabetic, 441 Motor pathways, 128-129 Motor unit, 129, 130 Movement, joint, seeJoint, motion MRI, see Magnetic resonance imaging Mucosal surfaces, microbiological sampling, 322 Mudguard, 248 Mulder's click, 418 Mules, 254, 255 Multifactorial conditions, 7 Multineuronal tract, 129 Multiple sclerosis, 114, 125, 154 case history, 70 signs and symptoms, 134, 135 Multistix 8SG, 329, Plate 28 Muscle, 121-122 activity in gait, 173 assessment, 165-166 atrophy (wasting), 166 in arterial insufficiency, 98 denervation, 148 disuse, 145 knee, 182
biopsy, 150 bulk,166 fasciculation, 148 spasm, 166 spindles, 132 strength (power) testing, 39, 148, 165-166 tears, grading, 393 tone, 166 in coordination disorders, 152 in lower motor neurone lesions, 149 in upper motor neurone lesions, 145-146, 155 weakness (paresis), 71, 146-147, 155 children, 368 as presenting problem, 134-135 Muscular dystrophy, 71, 147 Becker's, 147 Duchenne, 135, 147 facio-scapulo-humeral, 147 limb girdle, 147 Musculoskeletal disease, 74, 445-446 elderly, 457-458 preoperative assessment, 477-478 seealso Orthopaedic assessment Musculotendinous injuries, risk factors, 377, 378, 380 Musgrave footprint, 311-312 Myasthenia gravis, 114, 125, 135, 148 Mycology, 228 Myelin, 115, 125 Myelography, 138 Myocardial infarction (MI), 64 surgical risk, 473-474, 475 symptoms,65,90-91 Myocardial perfusion scintigraphy, 95 Myopathies, 114, 146 classification, 147 electromyography, 149 Myositis ossificans, 285-286 Myxoedema, pretibial, 72 N Naevi blue, 241 junctional, 241 pigmented, 240-241 Nails, 223-226 anatomy, 223-224 in arterial insufficiency, 99 clippings, 228, 322 clubbing (hippocratic), 92, 224, 225 colour changes (chromonychia), 224, 225,226 elderly, 454, 458 growth rate, 224-225 involution (pincer), 224, 225 in lichen planus, 225, 234-235 loosening/ shedding, 226 pattern of affected, 224 periungual changes, 226 pits, 225-226
plate shape, 225 in psoriasis, 225, 233-234 spooning (koilonychia), 92, 224, 225 surface texture, 225-226 thickness, 226 yellow, 111 Nalidixic acid, 60 Names, 23 Nausea, 68 Navicular accessory, 407,408 position, 171 stress fractures, 375 Naviculocuneiform fault, 280 Necrobiosis Iipoidica, 108, 235, Plate 18 Necrosis, 99, 223 seealso Gangrene Neonatal history, 345 Neoplasia, see Tumours Neospinothalamic tracts, 128 Nerve biopsy, 144, 150 conduction test, 143-144, 149, 392 damage, classification, 139 entrapments, 415-417 impulse, 124-126 injuries, 154 seealso Afferent nerves Nervous system, 115-133 autonomic, 87-88, 122-124 central, see Central nervous system function, 124-133 histology, 115-116 organisation, 116-124 peripheral, 120-121 somatic, 122 Neurofibromatosis, 114 Neurological assessment, 133-155 children, 346, 347, 368 purpose, 113-114 sources of error, 50-51 Neurological disorders, 114,446-447 causes, 133-134 elderly, 456-457 exercise in, 383 history, 70-71, 134-135 observation, 135-136 perioperative risk, 477 signs and symptoms, 155 Neurones, 115-116 Neuropathic ulcers, 154,441,443, Plates 32-33 Neuropathies, 134 Neuropraxia,139 Neurothesiometers, 51, 139, 142 Neurotips, disposable, 142, 143 Neurotmesis,139 Neurotransmitter, 125 Neutral calcaneal stance position (NCSP), 202-204 Neutral position, foot, 199,201 Night cramps, 65-66, 97-98 Nikolsky's sign, 232
INDEX 495
90:90 test, 185, 186,354 Nitrite, in urine, 330 Nitroglycerine, 91 Nociceptors, 126 Nocturia, 69 Nocturnal cramps, 65-66,97-98 Nodes of Ranvier, 116, 125 Nodules, 222, 223 rheumatoid, 445 Noise, electrical equipment, 47 Nominal categorisation, 39-40 Non-verbal communication, 16-21 Non-weightbearing examination, 162, 163,175-202 children, 350-352, 367-368 leg and foot alignment, 197-202 Nonsteroidal anti-inflammatory drugs (NSAIDs), 67, 68, 458, 482 Noradrenaline (norepinephrine), 122 Nuclear medicine, 298-300 Numbness, 71, 135 Nutrition, sports injuries and, 388 Nystagmus, 152, 155
o Ober's test, 178-180 Obesity, 59, 381 surgical risk, 471 Observation, 4, 59,164 children, 346 pain assessment, 401 Obturator nerve injury, 178 Occipital lobe, 117, 118 Occuloplethysmography, 137 Occupation, 63 at-risk foot, 434 footwear, 256 nail changes, 225 preoperative assessment, 473 skin disease, 220 Odour skin, 222 urine, 329 Oedema (swelling), 92, 222 acute, 5 in arterial insufficiency, 99 in deep vein thrombosis (DVT), 107 differential diagnosis, 99 knee, 182 in lymphoedema, 110 non-pitting, 109 peripheral, 65, 69, 92 pitting, 109 tibiofibular segment, 186 in venous insufficiency, 109, Plate 8 Oestrogen deficiency, 459 Older athletes, 377 Oligodendrocytes, 115 Oliguria, 69 Olliers disease (multiple enchondrornatosis), 292, 294 Oncotic pressure, 86 Onychauxis, 224, 226
Onychocryptosis, 224 Onychogryphosis, 224, 226 Onycholysis, 224, 226 Onychomadesis, 224, 226 Onychomycosis, 224, 238 Oral reflex, 347 Orthopaedic assessment, 157-209 children, 347-352 elderly, 457-458 gait analysis, 163, 167-175 guidelines, 163-164 limb-length inequality, 206-208 non-weightbearing, 162, 163, 175-202 palpation, 164-167 preoperative, 477-478 process, 162-163 purpose, 161-162 static (weightbearing), 162, 163, 202-206 terms of reference, 157-161 Orthopnoea, 91 Ortolani's manoeuvre, 353 Os peroneum, 281 Os tibiale externum. 281 Os trigonum, 190, 281, 407-408 Os vesalianum, 281 Osgood-Schlatter's disease, 289, 354 case history, 182 young athletes, 376-377 Ossicles, accessory, 281, 282, 407-408 Osteoarthritis (OA), 403-404, 446 hip, 176 preoperative assessment, 477-478 X-ray assessment, 287-288, 289, 404 Osteochondritis dissecans, 354, 405-406 Osteochondroma, 292, 293, 411 Osteochondrosis, 289-290, 354, 367 Osteoid osteoma, 293, 411, 412 Osteomyelitis, 422 diagnosis, 437-438 X-ray assessment, 287, 288, 422 Osteopenia, 283 Osteopetrosis, 285 Osteophytes, 288, 289 Osteoporosis, 283-284, 459 in female athletes, 377-378 preoperative assessment, 480 Osteosarcoma, 293-294, 411 Osteosclerosis, 283, 284-285 Outsole, seeSole Overuse injuries extrinsic risk factors, 383-385, 386-387 history taking, 390 intrinsic risk factors, 377, 379, 381 Oxygen consumption, 316 tension, transcutaneous (TcPOz)' 105,439 transport, 89 p Pachyonychia congenita, 226, 229 Packed cell volume (PCV), 332, 333
Paediatric patients, 341-369 seealso Children Paget's disease, 187,284-285 Pain, 5 in amputees, 139 assessment/measurement, 34-35, 398-403 at-risk foot, 438 postoperative, 482 at-risk foot, 438 charts, 34-35 diaries, 35, 36 dimensions, 33 foot, 397-424 gating mechanism, 131 hip, 175, 176 knee, in children, 354, 367 limping in children, 365-368 in neurological disorders, 134, 155 in peripheral vascular disease, 97-98 postoperative, 482 referred, see Referred pain sensation testing, 140, 142-143 sports injuries, 390-391 subjectivity, 397-398 withdrawal reflex, 131 Pain perception profile, 401 Palaeospinothalamic tract, 128 Pallor, 92 Palmen's sign, 353 Palmoplantar keratoderma (PPK), 229, 231, Plate 14 Palpation, 164-167 Panniculitis, 239 Papule, 222, 223 Paraesthesia, 71, 139, 155 Paralanguage, 20-21 Parallax error, 49 Paralysis, 146, 147, 155 Paraphrasing, 16 Paraplegia, 145 Parasympathetic nervous system, 88, 122, 123 dysfunction, 153 Parents, 343, 344 Paresis, see Muscle, weakness Parietal lobe, 117, 118 Parkinsonism, 114, 125, 135 Parkinson's disease, 135, 151, 152 Paronychia, 224, 226 Parsponea metatarsalia, 281 Patch testing, 228 Patches, 223 Patella, 181-182 children, 351 compression test, 354 fish eye, 170 position, 170, 182 Q angle, 186,354 size, 182 squinting, 170, 356 Patella tendonitis, 385, 390 Patellar tap test, 183 Patellar tendon reflex, 144, 145, 347
496
INDEX
-----------------------------------------Patellofemoral joint tests, 183 Patellofemoral syndrome, 377, 379, 390 Patient-centred approach, 12 Patients assessment, 3-10 'at risk', seeAt-risk foot choice of practitioner, 31 confidentiality, 9-10, 25 expectations, 6, 22-23 measurement errors, 50-51 measurement techniques, 41 perceptions of problems, 30 records, see Records stereotyping, 21 Patrick's test, 178 Pattern recognition, 5 Pedigree chart, 62 Pedobarograph,309-311 Pelvis in children, 350-351 tilt, 170 Pemphigus, 232 Perinatal history, 345 Peripheral arterial occlusive disease (PAOD), see Peripheral vascular disease Peripheral nervous system (PNS), 120-121 Peripheral neuropathy, 71, 114, 417, 446 diabetic, 417, 441--442 elderly, 456--457 sensory testing, 140-143 Peripheral resistance, 88 Peripheral vascular disease (PVD, PAOD),95-106 causes, 95-96 clinical tests, 99-104 in diabetes, 442 elderly, 456 exercise in, 382 Fontaine classification, 97 history, 65-66, 95-96 hospital tests, 104-106 observation, 98-99 symptoms, 97-98 seealso Ischaemia Peripheral vascular system anatomy, 81-86 assessment, 65-66, 95-111 physiology, 88-89 Peritendinitis, 412--413 Periungual disorders, 226-227 Pernicious anaemia, 89,444,460 Perniosus (chilblains), 235, 369 Peroneal muscle atrophy, see Hereditary motor and sensory neuropathy Peroneal muscles, 194 Peroneal spastic flat foot, 363-364, 409 Peroneal tendons subluxing,413 tenosynovitis, 412, 413 Personal space, 18-20 Perthes' disease, 289, 367
Perthes test, 109 Pes cavus, 173, 262, 263 Petechia, 222 Phalangeal fractures, 291 Phantom limb, 139 Phlebitis, 106, 107, 108 Phlebo-thrombosis, 106 Phonocardiography, 95 Photoelectric plethysmography, 105 Photography cine, 314 digital, 41--42, 436 skin problems, 228-229 wounds/ulcers, 436 Physical appearance, 20 Physical build, 380-381 Physical fitness, 380, 388 Physiological cost index (PCD, 316 Physiological measures, pain, 401 Piezogenic papules, painful, 239 Pigmented skin lesions, 240-242 Pinprick testing, 140, 142-143 Piriformis test, 180 Piston (telescope) sign, 353-354 Pitted keratolysis, 238, Plate 22 Pivot shift test, 184 Placing reflex, 347 Planes, cardinal body, 157, 158 Planimetry, wound, 436 Plantar, 158 Plantar dermatitis, juvenile, 236, 368-369 Plantar fasciitis, 63, 419--420 Plantar fat pad, atrophy, 410 Plantar fibromatosis, 420 Plantar pressure sensors, see Pressure measurement sensors, plantar Plantar reflex (Babinski sign), 145, 146, 347 Plantarflexion, 158, 159 Plantarflexors, 193 Plantaris muscle, 193 Plaque, 222, 223 Plasma, 331 viscosity, 333 Platelet count (thrornbocytes), 332, 333 Play, 344 Plethysmography, 110 photoelectric, 105 Podotrack plantar pressure measuring device, 41 Pole test, 104 Poliomyelitis, 114, 147, 148,446 Polycythaemia, 444 Polydactyly, 281 Polymyositis, 147,446 Polyneuropathy, 134 Polyuria, 69, 72 Pompholyx, 233 Pons, 117, 118 Popliteal angle, in children, 355-356 Porocarcinoma, 243 Poroma, eccrine, 242 Porphyrias, 479
Positron emission tomography (PET) scanning, 105 Post-neonatal history, 345 Post-thrombotic syndrome, 106-107, 108,109 Posterior, 158 Posterior cruciate ligament, 184 Posterior talofibular ligament (PTFL), 190 Posterior tibial artery (tibialis posterior) patency testing, 100 pulse, 51-52, 100, 101 Postmenopausal syndrome, 440, 459 Postoperative assessment, 481--482 Posture, 17-18, 133 approaching, 17-18 contraction, 18 early childhood, 342 expansion, 18 withdrawal, 18 Potassium, plasma, 334 Potassium hydroxide, 228, 323 Pott's fracture, 291 Practitioners appearance, 20 measurement errors, 47-50 measurement techniques, 41 patient's choice of, 31 Precision, 42 Prednisolone, 60 Pregnancy history, 345 surgery in, 471, 479 X-rays in, 271 Premature babies, 345 Premotor cortex, 128 Preoperative assessment, 469, 470--480 current health status, 471 factors affecting surgical risk, 478--480 home circumstances, 472--473 investigations, 480 past and current medication, 471--472 past medical history, 472 physical examination, 478 purpose, 470--471 systems enquiry, 473--478 PREPSOCS indicators of foot infection, 437 Presenting problem, 29-36 articulating, 30-31 assessment,31-35 high priority, 5 history, 31-33 patient perceptions, 30 Pressure, 308 sensation testing, 141 Pressure measurement sensors, plantar, 41, 46--47,309-313 dynamic range, 47 platform systems, 46, 309-312 sampling frequency, 47 in-shoe systems, 46--47,312-313 spatial resolution, 47
INDEX 497
Pretibial myxoedema, 72 Problems, patients', 15,29 seealso Presenting problem Processus uncinatus, 281 Pronation, 161 abnormal/excessive (flat foot), 173, 360-364 gait, 174 non-weightbearing assessment, 192-193 objective indices, 362 rigid, 204, 363-364 weightbearing assessment, 202-204 X-ray assessment, 276-277, 280
Propionibacterium minutissimum, 228, 238 Propranolol, 60 Proprioception assessment, 150-152 testing, 140, 151 Proprioceptors, 126 Propulsion, 167-168,169,173 Protein, in urine (proteinuria), 330 Proteus spp., 325 Prothrombin time (PT), 332, 333 Protractor, 164 Proxemics, 18-20 Proximal, 158 Proximal articular set angle (PASA), 278 Pruritus elderly, 459 lesions causing, 439 Pseudogout, 286-287,420-421
Purpura, 223 senile, 458 Pus, 322 Pustule, 222, 223 Pyogenic granuloma, 242, Plate 25 Pyuria, 330
Q Q angle, 186,354 Quadriceps muscle bulk evaluation, 185, 354 function testing, 185, 354 Quality of life (Qol.) elderly, 461, 463 measures, 401, 463 Quality of motion (QOM), 165 Quantitative computed tomography (QCT),283 Quarter (shoe), 247 Questionnaires foot specific (pain), 402-403 medical health, 22, 59, 77-78 pain, 34,400-401,438 Questions, 13-15 closed,13-14 leading, 14 open, 13 personal/intimate, 15 practical tips, 14-15 probing, 14 4-Quinolones, 60
Pseudomonas aeruginosa, 325 Psoriasis, 217, 233-234 arthritis, 234, 445 case history, 214 children, 369 clinical examination, 220, 221, 222, 231 guttate, 234, 369 nail changes, 225, 233-234 palmar plantar pustular, 234, Plate 16 plaque, 234, 369 pustular, 229, 234 Psychiatric status, preoperative assessment, 479 Psychological factors at-risk foot, 433-434 skin disease, 214 sports injuries, 381-382 Pulmonary circulation, 81, 89 Pulmonary embolism, 66, 67, 106, 107 Pulmonary oedema, 65 Pulse(s), 88, 100 Doppler assessment, 102-103 palpation errors, 51-52 pedal, 100-101,438 points (pressure points), 100, 101 pressure, 93 quality, 93 rate, see Heart rate 'Pump (heel) bumps', 418-419 Purkinje fibres, 87
R Radiation, effects on tissue, 270 Radiculopathy, 134 Radiographic assessment, 269-300 alignment, 276-282 basic (ABCS), 275-287 bone density, 282-285 cartilage, 285 soft tissue, 285-287 specific pathologies, 287-296 seealso X-rays Radiographic views anteroposterior (AP) ankle, 273-274 Anthonsen's, 404 dorsiplantar (DP), 271, 272, 276-279 dorsiplantar oblique, 274, 275 lateral (weightbearing), 271-273, 279-280 Radiolucency, increased, 283 Radiopacity, increased, 282-283 Random errors, 44 Range of motion (ROM), 164-165 Rating scales, 39 numerical pain, 34 Raynaud's disease, 97, 225 Rays fifth abducted, 205 dorsiflexed, 201 plantarflexed, 201
first dorsiflexed (metatarsus primus elevatus), 195, 196,201 plantarflexed, 201 seealso Metatarsals Re-assessment, 7-8 Rearfoot alignment, to forefoot, 199-201 children, 352 deformity, 171 varus, 192,203,204 partially compensated, 361 Recede (shoe last), 249 Records, 8-9,21-22 computerised, 8, 21 confidentiality, 9-10, 25 handwritten, 8, 22 location of presenting problem, 32 pro-forma, 8, 22 Rectus femoris muscle, 185 Red blood cells, see Erythrocytes Referral indications for medical/surgical, 447-448 letters, 22 Referred pain, 139, 424 features, 33, 143 in orthopaedic assessment, 163 Reflection technique, 16 Reflex arcs, 131-133 Reflex sympathetic dystrophy (RSD), 284,423 Reflexes, 130-133 crossed extensor, 132 diminished, pendular, 155 early development, 346, 347 grading of responses, 144 pain withdrawal, 131 stretch, 132-133 tendon, see Tendon reflexes Reiter's disease, 70, 229, 240, 445 Relaxed calcaneal stance position (RCSP),202-204 Reliability, 42-43 interobserver, 43 intraobserver, 43 Renal failure/ disease foot complications, 447 preoperative assessment, 476-477 skin changes, 240 symptoms,69,72 Renal pain, 69 Renal transplant, 225 Repeatability, 42 Resected organs, 337 Resistance vessels, 88 Resources, measurement techniques and,41-42 Respiratory disease, 66-67 at-risk foot, 447 clubbing, 225 elderly, 460-461 preoperative assessment, 475 Rest pain, 98
498
INDEX
-----------------------------------Rete pegs, 217 Reticular activating system (RAS), 128 Reticular formation, 117 Reticulocyte count, 332, 333 Retrocalcaneal bursitis, 418-419 Rheumatic fever, 65 Rheumatoid arthritis, 445 case histories, 74, 382, 444 preoperative assessment, 478 skin changes, 240 steroid therapy, 60, 441 X-ray assessment, 288-289, 290 Rheumatoid factor, 335, 445 Rickets, 355 vitamin D-resistant, 447 Rigidity, lead-pipe/ cog-wheel, 152, 155 Risk assessment, 4-5, 433-447 elderly, 465-466 holistic overview, 433-435 local indicators, 435-438 preoperative, see Preoperative assessment systems approach, 438-447 Romberg's sign, 151-152 Rose's valgus index, 362 Rubber, 253 Running uphill and downhill, 385 windmilling style, 356 Ryder-Seiffel tuning fork, 141-142
S Sacral plexus, 119 Sacroiliac joint provocation test, 178 S(AD) SAD ulcer classification system, 432-433 Saddle (sports shoe), 248 Sagittal plane, 157, 158 deformity, 161 joint motion, 158, 159 joint position, 161 Sagittal Raynger, 195 Salbutamol, 60 Salt intake, excess, 72 Saltatory conduction, 125 San Antonio/Texas ulcer classification system, 432 Sandals, 253-254 Saphenous nerve, 119 Scabies, 238 Scale, 222, 223 Scannergram, 207-208 Scars, 223 Scheuermann's disease, 289 Schistosomiasis, 154 Schwarm cells, 115 Sciatic nerve, 119 Sciatica, 424 Scleroderma/ systemic sclerosis, 225, 240,288 Scoliosis, 202, 349 Scopulariopsis breoicaulis, 327
Scouring test, 178 Sebaceous glands, 218 Seborrhoeic warts, 240 Self-referrals, 22 Senses, 126 Sensitivity, 44, 319-320 Sensorimotor cortex, 127, 128 Sensory cortex, 127 Sensory deficits causes, 138 elderly, 456-457 Sensory nerves, 122 see also Afferent nerves Sensory neuropathy, diabetic, 441 Sensory pathways, 126-128 Sensory receptors, 126 Sensory testing, 50-51,138-144 Septic arthritis, 422, 446, 478 Sequestrum, 287 Sero-negative arthritides, 445, 478 Serology, 335 Sesamoiditis, 411 Sesamoids interphalangeal joint, 281 metatarsal head, 281 axial view, 274 position, 277-278, 280 see also Patella Sever's disease, 290, 376 Sex, see Gender Sexually transmitted infections, 70 Shank (shoe), 247, 248, 253 Shin splints, 389, 391 Shingles, 135,237 Shock meter system, 313 Shoe and Allied Trades Research Association (SATRA), 264, 265 Shoes, 245 allergy to, 253 children, 258, 352-353 comfort, 257 components, 246-248 construction, 248-253 depth,259 everyday, 264 fit, assessment, 256-261 fitting problems, 260-261 fixation, 260 flare, 249, 259 function, 260 Goodyear welt, 251 heel to ball length, 249, 258 inside, examination, 264 inside border shape, 259-260 lace-up, 247, 253-254, 260 lasts, 248-249 length, 249-250, 257-258 materials, 252-253 measurement, 249-250 moulded, 251, 252 sports, 248, 383-384 stitchdown, 251 Strobel-stitched, 251, 252 stuck-on (cement), 250-251
styles, 253-255 suitable, 253-255 unsuitable, 255 suitability, 264 wear marks, 261-264, 384 width, 250, 258-259 Short form-36 (SF-36), 401--402, 463 Shoulder position, 168, 348 swimmer's, 385 Shuttle run test, 20 min, 380 Sickle cell disease, 63, 66, 444 surgical risk, 66, 475, 476 Sickness impact profile (SIP), 401 Single-limb heel-raise test, 190 Single-photon absorptiometry (SPA), 283 Sinoatrial (SA) node, 87 Sinus, 223 Sinus tarsi, 191, 279 syndrome, 414 Skew foot, 358, 359 Skin ageing, 220, 454, 457 allergies/ drug eruptions, 235-236 appendages,215,216,218-219 see also Nails assessment, 5, 213-243 approach,213-214 elderly, 458-459 purpose, 214 recording, 228-229 at-risk foot, 439-440, Plates 20-21 barrier function, 217 biopsy, 228 blistering disorders, 231-232 blood supply, 218 colour interpretation, 98 lesions, 221 in venous insufficiency, 107-108 disease, 213 clinical examination, 220-227 distribution, 220, 221 elderly, 454 frequency, 214-215 history taking, 219-220 investigations, 227-228 lesion morphology, 221-223 primary lesions, 222 psychological aspects, 214 secondary lesions, 222, 223 subcutaneous layer, 239 dry, 439, Plate 30 functions, 215, 217, 428 hyperkeratotic disorders, 229-231 infections, 236-238 elderly, 458 investigations, 227-228 infestations/insect bites, 238-239 inflammatory conditions, 232-235 lymphatics, 218 metastasis, 243, Plate 26 microbiological sampling, 322
INDEX 499
-----------------------------_. odour, 222 over-moist (macerated), 439, Plate 31 perfusion pressure (SPP), 105-106 pigmented lesions, 240-242 scrapings,228,322,323 structure, 215-219, Plate 9 in systemic disorders, 239-240 transparent, syndrome of, 458---459 tumours,242-243 vascular resistance (SVR), 105-106 viability, see Tissue, viability Skyline/Allis test, 207 Slipped capital femoral epiphysis (SCFE),367 Smoking, 61, 135 cardiovascular problems, 91 preoperative assessment, 472, 475 Social habits, 135 Social history, 57-58, 63-64 Society of Chiropodists and Podiatrists, 9 Socioeconomic status, 434 Socks, 264-265 Sodium, plasma, 334 Soft tissue atrophy, 98 masses/tumours, 420 MRI imaging, 296 X-ray assessment, 285-287 Sole, 247 materials, 253 wear marks, 261-262, 263 Somatotopic organisation, 127 Spasticity, 145 clasp knife, 145 Special needs, patients with, 31 Specificity, 44 Speech defects, 155 scanning, 155 Spina bifida, 114, 154 occulta, 63, 349 Spinal cord anatomy, 118-119, 120 ascending pathways, 127, 128 descending pathways, 127, 129 function, 126-127, 129 lesions/ compression, 146, 154 Spinal nerves, 120-121 Spine, 202,348-349 Spinocerebellar tract, 128, 129 Spinothalamic tract, 128 Splinter haemorrhages, 92, 224, 225 Sports, 373-393 equipment, 383-384 history, 63, 389-390 injuries, 373 assessment environment, 375-376 assessment principles, 373-374 clinical examination, 391-392 grading systems, 393 history taking, 387-391 investigations, 392-393 previous, 378, 390
risk factors, 376-387 specific to sport, 385-386 medicine team, 374-375 podiatrist, 374-375 preoperative assessment, 473 shoes, 248,383-384 Squamous cell carcinoma (SCC), 108-109,243 Squatting tests, 180, 354, 392 Staheli's arch index, 362 Staphylococcus aureus, 237, 325, 326 Starling's law of the heart, 89 Startle reflex, 347 Stasis syndrome, see Post-thrombotic syndrome Step length, 307 Stepping reflex, 347 Stereotyping, 21 Steroid therapy long-term, 59, 60, 441 myopathy, 147 surgical risk, 472 Stevens-Johnson syndrome, 235 Stiffener (shoe), 247 Still's disease, 289 Stockings, 264-265 Stork test, 180 Straight-leg-raise test, 180 Strain gauge transducers, 312 Stratum compactum, 217 Stratum corneum, 217 Stratum germinativum, 216 Stratum granulosum. 216-217 Stratum spinosum, 216 Strength, sports injuries and, 380-381 Streptococcus pyogenes, 237-238, 325-326 Stress, sports injuries and, 381 Stress fractures, 291, 408 navicular, 375 risk factors, 377-378, 379, 385, 387 tibia, 391 Stress radiographs, ankle, 274 Stress tests ankle ligaments, 188-190 knee ligaments, 183-184 sports injuries, 391-392 Stretch reflex, 132-133 Stretching, pre-exercise, 380 Striae, 223 Stride length, 307 Stroke, see Cerebral vascular accident Stroke volume, 87 Subacute combined degeneration of spinal cord, 114,460 Subcutaneous fat layer, 218 atrophy, 239 disorders, 239 Subluxation, 165 Subtalar joint (STJ), 187, 191-194 abnormal pronation, 192-193 motion, 192, 193 position, 171, 172 varus, 192
Subungual exostosis, 225, 226, 408---409, Plate 11 X-rays, 292, 293, 409, 412 Sudecks atrophy, 284 Summarising technique, 16 Summation, 125 Sunburn, 235 Sunlight exposure, 454 Superficial peroneal nerve, 119 entrapment, 416---417 Supination, 161 Surface area, wound, 435---436 Surgery, 469---482 complications, 481 postoperative assessment, 481---482 preoperative assessment, 468, 469---480 previous, 62, 387-388 Swabs, 228,322,437 Swallowing, difficulty in, 68 Sweat glands, 218-219, 227 Sweating, 218 absent (anhidrosis), 153,227 disorders, 227 excessive, see Hyperhidrosis Swelling, see Oedema Swivel test, 364 Sydenham's chorea, 151 Symmetry of motion (SaM), 165 Sympathetic nervous system, 87-88, 122, 123 dysfunction, 153 Sympathetic tone, 88 Synapses, 116, 125-126 Synchondrosis, 409 Syncope (fainting), 65, 70, 136, 474 Syndesmosis, 409 Synostosis, 409 Synovial chondromatosis, 293 Synovial fluid examination, 337 Synthetic shoe materials, 252, 253 Syphilis, 70, 229 Syringomyelia, 114, 154 Systematic errors, 45 Systeme International (SD units, 38 Systemic (disseminated) lupus erythematosus (SLE), 240, 288, 446,478 Systemic sclerosis/scleroderma, 225, 240,288 Systems enquiry, 59, 64-74 preoperative assessment, 473---478 Systole, 87
T Tabes dorsalis, 114, 150 Tachycardia, 92 Talar tilt test, 189-190 Talipes equinovarus, congenital, 360 Talocalcaneal bar (coalition), 363, 409 case history, 410 investigations, 281, 283, 297, 409 Talocalcaneal notch, 276
500
INDEX
-------------------------------------------Talocrural joint (TCJ), 171, 187, 188-191 dorsiflexion, 188, 189 functional tests, 190 grading of ligamentous injury, 190-191 investigations, 191 motion, 188 osteochondritis dissecans, 405--406 proprioception, 191 stability (stress) testing, 188-190 strength, 190 Talus declination angle, 280, 352 neck fractures, 291 Tarsal coalitions, 187,409 case history, 410 investigations, 281, 283, 297, 409 rigid flatfeet, 363 Tarsal tunnel syndrome, 72, 143, 415--416 Team, sports medicine, 374-375 Telangiectases (telangiectasiae), 107, 222, Plate 4 Telescope sign, 353-354 TELOS system, 190 Temperature ambient clinic, 45, 51-52 lower limb in arterial insufficiency, 99 gradient, 99 measurement, 49-50 in venous insufficiency, 108 perception testing, 140, 142 Temporal lobe, 117, 118 Tendinitis (tendonitis), 390, 393, 412--413 Tendo calcaneus, seeAchilles tendon Tendon reflexes, 132-133 in cerebellar dysfunction, 152 in children, 347 diminished,155 in motor dysfunction, 144, 145, 149 Tendonosis, 390 Tensor fasciae latae, tightness, 178, 179 Terrain, exercise on uneven, 385 Thalamus, 117, 128 Thalassaemia, 63, 444 Thermoreceptors, 126 Thiamine deficiency, 135 Thigh movement, 170 Thirst, 72 Thomas's test, 178 Thomson's test, 187 Throat (shoe), 247 Thrombin time (TTl, 334 Thromboangiitis obliterans, 96, 438 Thrombocytes (platelet count), 332, 333 Thrombophlebitis, 106, 107 Thumb technique malleolar torsion, 198 metatarsal motion, 195 Thyroid disease, 72-73, 225, 459 seealso Hypothyroidism Thyrotoxicosis, see Hyperthyroidism
Tibia anterior spur, 404--405 children, 351-352 examination, 186-187 length inequality, 207 position, 171 sabre, 171, 187 stress fracture, 391 torsion, 187, 198-199,357-358 valgum, 204 varus (varum), 171, 187,204 Tibial nerve, 119 Tibialis anterior muscle, 193-194 Tibialis posterior artery, see Posterior tibial artery Tibialis posterior dysfunction syndrome (TPDS), 190 TIbialis posterior muscle, 193-194 Tibialis posterior tenosynovitis, 412--413 Tibiofemoraljoint motion, 183 stability, 183-185 Tibiofibular joint, inferior, 187 Time management, 7 Timed up and go test', 462 Tinea incognito, 238, 239 pedis, 229, 238, 368 Tinel sign, 143,415 Tiptoe-standing tests, 363, 392 Tissue ageing effects, 454 fluid,86 radiation effects, 270 sampling methods, 336-337 viability, 429--433 in arterial insufficiency, 98 classifying loss, 430--433 factors causing loss, 429--430 factors essential to, 429 foot at risk of losing, seeAt-risk foot in lymphoedema, 110 in venous insufficiency, 108 Tobacco use, seeSmoking Toe(s),204-206 adductovarus fifth, 206 alignment, 278-279 claw, 172,206 deformities, 364-365, 457 dorsally displaced, 206 flexor stabilisation, 204 flexor substitution, 204 formulae, 206 hammer, 204, 206 mallet, 206 position, 172, 201 puff, 246, 247 retracted, 206 spring, 249 trigger (hallux extensus), 196,206 turf, 384 walking, 174-175, 348 seealso Hallux
Toe-in, 307 seealso In-toeing Toe-out, 307 Toecap, 247 Tongue (shoe), 247 Tonic neck reflex, 347 'Too many toes sign', 361, 413 Torque conversion, 170 Touch,18,49-50 functional, 18 perception testing, 140-141 in skin assessment, 221-222 Tourniquets, in sickle cell disease, 66, 475,476 Toys, 344 Tractograph, 164 ankle dorsiflexion, 188, 189 malleolar torsion, 198 Trainers (sports shoes), 248, 383-384 Training errors, 386-387, 389 Transcutaneous oxygen tension (TcPOz)' 105, 439 Transient ischaemic attack (TIA), 136, 137 Transmalleolar axis, 357 Transtarsal joint, see Midtarsal joint Transverse plane, 157, 158 deformity, 161 joint motion, 158-161 joint position, 161 Trauma at-risk foot, 439 in children, 367 tissue viability, 430 X-ray assessment, 291 Travel, foreign, 64, 444, 473 Treadmills elderly, 457--458 gait analysis, 306 Tremor in cerebellar dysfunction, 151 classification, 136 intention, 136, 151, 155 in Parkinson's disease, 152 rest, 155 Trendelenburg gait, 175, 348 Trendelenburg test, 180 children, 349-350, 368 Trephine, 337 Trichophyton mentagrophuies, 238, 327 Trichophyton rubrum, 238, 327 Trigger toe (hallux extensus), 196, 206 Triplanar motion, 161 Tropical diseases, 64 Trunk position/rotation, 170 Tumours, 222 bone, 292-296 malignant, see Malignant tumours painful foot, 411--412 skin, 242-243 soft tissue, 420 Tuning fork, 141-142 Turf toe, 384
INDEX 501
Turner's syndrome, 284 Two-point discrimination, 140-141 U Ulcers, 223 classification, 431-433 diabetic foot, see Diabetes mellitus, foot ulcers elderly, 457 ischaemic, 98-99, 442, 443, Plates 35-36 neuropathic, 154,441,443, Plates 32-33 as presenting problem, 5 trophic, 430 venous, 108-109,443, Plates 7-8 seealso Wounds Ultrasound, 300 Doppler, see Doppler ultrasound duplex in neurological disorders, 137 in venous insufficiency, 110 quantitative, calcaneum, 283 in sports injuries, 392 Ultraviolet light exposure, 454 Underweight, 59-60, 471 Uniforms, 20 Units of measurement, 38 Upper (shoe), 246-247 crease marks, 263 deformation, 263 materials, 252 Upper motor neurones (UMNs), 128-129 lesions, 144-146, 150,457 Urea, serum, 334 Uric acid, serum, 334, 421 Urinalysis, 328-331 indications, 328 preoperative, 480 Urinary tract infection (UTI), 330-331, 480 Urine culture, 330-331 microscopy, 330 pH,330 physical examination, 328-329, Plate 27 reagent testing, 329-330, Plate 28 specific gravity, 329-330 specimen collection, 328 Urobilinogen, 330 Urticaria, 223
V Vagus nerve, 122, 123 Valgus deformity, 161 Valgus index, Rose's, 362 Valgus stress test, 183-184 Validity, 43-44 Valleix phenomenon, 415 Valsalva manoeuvre, 153
Valvular heart disease, 474, 475 Vamp, 246, 247 Varicose veins, 106-107, 108 Varus deformity, 161 Varus stress test, 183 Vascular assessment, 79-111 elderly, 455-456 purpose, 79-80 Vasculitis, 96, 446 clinical fea tures, 234 in rheumatoid arthritis, 445 Vasoconstriction, 88 Vasodilation, 88 Vasospastic disorders, 369, 382, 438 Veins, 81-82, 83 function, 89 valves, 81-82 varicose, 106-107, 108 Velocity, walking, 307 Vena cava, 80, 81 Venography (venous angiography), 110,392 Venous insufficiency, 106-110 causes, 106 chronic, see Post-thrombotic syndrome clinical tests, 109 elderly, 456 history, 106-107 hospital tests, 110 observation, 107-109, Plates 4-8 stasis dermatitis, 108,233, Plate 6 symptoms, 107 Venous return, 89 Venous thrombosis, 106 deep (DVT), 106-107, 109 Venous tree, 81-82 Venous ulcers, 108-109,443, Plates 7-8 Venules, 81, 83 Verbal (descriptor) scales (VDS, VS), 34,400 Verrucae, 237, 368, Plate 20 Vertebrae, alignment, 202 Vesicle, 222, 223 Viability, tissue, see Tissue, viability Vibration perception elderly, 457 testing, 51, 140, 141-142 Videotaping kinematic gait analysis, 314-315 skin assessment, 228-229 visual gait analysis, 306 Virchow's triad, 106 Viruses culture, 228 identification, 327-328 infections, 237, 320 Vision, role in measurement, 48-49 Visual analogue scales (VAS), 34, 399-400,438 Visual defects, 155 Vitamin B12 deficiency, 114, 154,444, 460
Vitamin D deficiency, 284 excess, 284 Vitamin deficiencies, 155 Vomiting, 68
W Waiting room, 23 Walking barefoot, 255, 260 base, 307 distance, 103 early childhood, 342, 347-348 footwear assessment, 255, 260 reflex, 347 toe, 174-175,348 velocity, 307 seealso Gait Wardrobe,256 Warfarin, 60, 472 Warts mosaic, 237 periungual, 226, 237 plantar (verrucae), 237, 368, Plate 20 seborrhoeic, 240 Weal, 222, 223 Wear marks, shoe, 261-264,384 Weighing scales, calibration, 45-46 Weight, see Body weight Weightbearing examination, 162, 163, 202-206 children, 348-350 Welt, 247, 248 West Haven-Yale multidimensional pain inventory (WHYMPI), 401 White blood cells, see Leucocytes White patches (atrophia blanche), 107-108, Plate 5 Wipe test, 183 Wisconsin brief pain inventory, 401 Women postmenopausal, 440, 459 radiation safety, 271 shoes, 246, 256 sports injuries, 377-378 Wood's light, 227-228 Wounds assessment, 435-438 classification, 430-433, 481 colour, 437 depth,436 dressings, 481 healing, delayed, 435 infection, 437-438 loss of tissue viability, 429-430 margins, 437 microbiological sampling, 322 postoperative assessment, 481-482 surface area, 435-436 traumatic oersus trophic, 430 volume, 436-437 seealso Ulcers
502
INDEX
--------------------------------------X X-rays, 269-296 ankle, 191,273-274 assessment, see Radiographic assessment chest, 95 child's foot, 343 generation, 269-270 in hallux valgus, 364-365 knee, 186
in lymphoedema, 111 ordering, 270-271 in osteoarthritis, 287-288, 289, 404 preoperative, 480 in sports injuries, 392 subungual exostosis, 292, 293, 409, 412 views, see Radiographic views Xanthoma tuberosum multiplex, 287
Xiphisternum, 208 y Yellow nail syndrome, 111 Young's test, 178
z Z foot, 358, 359
THE MEDICAL AND SOCIAL HISTORY
rr
Appendix: Medical Health Questionnaire
Please complete the health questionnaire in your own time. Take as long as you feel you need. If there are any areas of the form that you are not clear about, please ask the practitioner for help. It is important that we know about all aspects of your health as this may affect your legs and feet and may be important when deciding the best form of treatment. Your foot/leg problem Have you had any previous treatment for your feet? Yes/No Who provided the treatment?
Were any X-rays taken? Yes/No Were any blood samples taken? Yes/No Your general health Are you generally well? Yes/No Are you under a doctor or consultant currently? Yes/No Are you sleeping well? Yes/No What is your weight?
For women, could you be pregnant? Yes/No Past medical history Has your weight recently changed? Yes/No If yes, how has your weight changed?
Are you taking any medication or tablets? Yes/No If Yes, please list below:
Are you allergic to anything? Yes/No If Yes, please list below: Do you smoke? Yes/No If Yes, how many do you smoke per day? Have you ever: Been off sick from work for more than a week? Yes/No Been admitted to hospital? Yes/No Undergone an operation? Yes/No Have you ever been under the care of a hospital consultant? Yes/No If Yes, please give details:
Do you take any recreational drugs? Yes/No Have you ever been injured at work? Yes/No Did you have any major childhood illnesses? Yes/No If Yes, please state which ones: Family history Does anyone in your family suffer from foot or leg problems? Yes/No Please place a tick if a member of your family suffered from any of these illnesses: Haemophilia 0 Sickle cell disease 0 Diabetes 0 Rheumatoid arthritis 0 Epilepsy 0 Social history What is your occupation?
Do you participate in sporting activities? Yes/No If Yes, please state which sports and how regularly do you participate:
Heart and circulatory problems Have you ever had: A heart attack? Yes/No Angina? Yes/No High blood pressure? Yes/No Heart failure? Yes/No Irregular heart rhythms? Yes/No Rheumatic fever? Yes/No A thrombosis or blood clot? Yes/No Night cramps? Yes/No Muscle cramps when walking short distances? Yes/No An ulcer on your leg or foot? Yes/No Chilblains? Yes/No Varicose veins and/or surgery? Yes/No Anaemia? Yes/No Hepatitis or jaundice? Yes/No Haemophilia? Yes/No Any other blood disorder? Yes/No Do you suffer from: Chest pains? Yes/No
78
SYSTEMS EXAMINATION
Shortness of breath? Yes/No Palpitations? Yes/No Swollen ankles? Yes/No Regular fainting? Yes/No Respiratory problems Have you ever had: Asthma? Yes/No Chronic bronchitis? Yes/No Emphysema? Yes/No A blood clot on the lung? Yes/No Have you ever had a cough for several months? Yes/No Do you ever bring up blood when you cough? Yes/No Diet and digestive problems Do you have any diet or bowel problems? Yes/No Are you troubled by toothache or gum swelling? Yes/No Do you suffer from indigestion or stomach ache? Yes/No Do painkillers like aspirin upset your stomach? Yes/No Genitourinary problems Have you ever had any 'waterworks' problems? Yes/No Is your sleep disturbed by the need to go to the toilet? Yes/No Have you ever had any sexually transmitted infections? Yes/No Are you in a high-risk group for blood-borne infections, such as hepatitis B or HIV? Yes/No
Head and nerve problems Have you ever injured your head? Yes/No Have you ever injured your spine? Yes/No Do you suffer from migraines or regular headaches? Yes/No If Yes, how frequently: Do you ever get numbness, weakness, tingling, heaviness or shooting pains in your legs and feet? Yes/No Do you ever get blackouts or feel faint? Yes/No Glandular problems Do you have sugar diabetes? Yes/No Do you have thyroid problems? Yes/No Are you always thirsty? Yes/No Do your hands and feet get particularly sweaty? Yes/No Are you particularly sensitive to cold? Yes/No Do you bruise easily? Yes/No Bone and joint problems Do you have any arthritis? Yes/No Do you ever get any aches and pains in your joints? Yes/No Have you any arthritis or long-standing muscle injuries? Yes/No Thank you for completing this questionnaire. Please add any further information that you think may be of use.
