Foot Problems in Older People Assessment and Management

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Foreword As our older population increases worldwide and The text is extremely well organised, easy to read society looks to the future, health policy and public and inclusive of the basic primary elements of geriatric health issues concerning the quality of life and health and related foot care. Each chapter provides a signifi- care are becoming major considerations. The moral cant and comprehensive list of references. The manu- and ethical responsibilities to care for the elderly are script provides a review of the epidemiology of foot problems that we face as health-care professionals problems in the elderly from a worldwide and inter- from all disciplines. There is a need to become aware national perspective, which is a first in current litera- of geriatric foot and related problems, their assess- ture. Prevalence and risk factors for foot problems ment, and management, and how they affect clinical (including age, sex, obesity and co-morbidities) are practice and the ability of our older citizens to remain related to the consequences of immobility, falls and vibrant and active members of their communities, and quality of life. to live their lives with dignity. This work includes practical discussions related The human foot is a marvel and has been called to the aetiology, assessment and management of the ‘mirror of health’. The early recognition of dis- common foot disorders and diseases along with an eases, disorders and systemic complications related to emphasis on primary management and the prevention the foot and its related structures has much to do with of complications. The text was designed to comple- all forms of prevention and management. A major ment existing geriatric and specialty texts such as component of the field of geriatric medicine and those in internal medicine, dermatology, foot surgery podogeriatrics is more than the ageing process itself. and foot orthopaedics to expand the concepts of care It includes clinical care, limb preservation, education, for older patients. Improving the quality of care to prevention, clinical management and the restoration help ensure years without pain and to enhance the of function. It also incorporates the social elements fulfillment of life are a demonstrated objective of this of life and the benevolent regard for each individual effort. patient as paramount to society in general. The physical changes related to assessment, the Geriatric clinical practice means more than just integument, keratotic changes, onychial disorders, caring for older individuals. It implies a philosophy of the vascular system, neurosensory changes, musculo- compassion and understanding that must be incor- skeletal system including foot deformities of the digits, porated into all health-care specialties that attempts forefoot and rearfoot are well documented. Pain and to improve health and well being for patients with arthritic changes have been properly presented. The chronic diseases and/or disabilities throughout their segments dealing with conservative and surgical lives. management enhance the primary care approach to patient care. The sections dealing with orthoses and Foot Problems in Older People: Assessment and Man- footwear are focused on the older patient. The agement critically and succinctly encompasses a wealth photographic illustrations and charts enhance the of information on the subject of geriatric foot care quality of the presentations and are augmented with that is applicable and practical for all professions a comprehensive list of references and bibliographic involved in the primary care of the older patient. Dr notations. Menz has accomplished this task in a masterful fashion. One individual who has demonstrated a breadth of Clearly this text is a ‘labour of love’ and prepared knowledge and understanding that provide great con- by an individual who has devoted much of his sistency in style and content has remarkably authored career to care, research and education related to foot this monograph. disorders in older patients. Dr Menz is to be

viii FOREWORD congratulated for this fine effort. He is a distinguished geriatricians and related health-care professionals to podiatrist, researcher, educator and the foremost understand and learn the principles and practice of scholar in the field of foot problems related to ageing providing foot care for geriatric patients and is a gem. in Australia. He is an established author, the Editor This book will help elevate the standards of care of the Journal of Foot and Ankle Research, and serves for older patients, internationally, and belongs in all on several editorial peer review boards of gerontology libraries that deal with the subjects of geriatric and and rehabilitation journals. gerontology. Foot Problems in Older People: Assessment and Man- Arthur E. Helfand agement provides an excellent and current foundation 2008 for the podiatric student, the podiatry profession,

Preface During the 20th century most countries in the world of foot conditions frequently observed in older underwent a remarkable demographic transition from people. While the book is primarily targeted towards high fertility and mortality rates to low fertility and a podiatry audience (particularly podiatry students), I mortality rates. Subsequently, we are now witnessing hope that it will also be of interest to general medical a substantial ageing of the population, with the most practitioners, nurses, physiotherapists, orthotists, rapid population growth being observed in the oldest orthopaedic surgeons, rheumatologists and indeed age groups – the oldest-old (85+ years) and cen- any other health professional who cares for older tenarians (100+ years). In 2000 it was estimated that people. there were 180 000 people in the world aged over 100 years and current projections suggest that this This book has 12 chapters, which can be broadly figure could reach 1 million by 2030. grouped into four sections: background information (Chs 1 and 2), assessment (Ch. 3), dermatological Population ageing poses significant challenges to and vascular disorders (Chs 4–7), musculoskeletal dis- health-care systems. While advances in health care orders (Chs 8–10) and treatment approaches (Chs 11 have contributed to increased longevity, a direct con- and 12). Chapter 1 provides a detailed coverage of sequence of this has been the corresponding increase the epidemiology of foot problems in older people, in prevalence of chronic diseases such as cancer, outlining the findings of several large-scale studies of cardiovascular disease, osteoarthritis and Alzheimer’s the prevalence, risk factors and consequences of foot disease. Whether population ageing has resulted in problems. Chapter 2 discusses the effects of ageing longer periods of ill-health prior to death (referred to on the integumentary, vascular, sensory and muscu- ‘expansion of morbidity’) or has delayed the age of loskeletal structures of the foot and outlines the clini- onset of disability (‘compression of morbidity’) con- cal implications of these changes. Chapter 3 is a long tinues to be debated. However, irrespective of which chapter that describes the assessment of the lower scenario proves to be correct, it is clear that health- limb in older people, from the initial assessment inter- care workers need to be prepared for an increasingly view and history taking through to diagnostic imaging. older caseload for some time to come. Chapters 4, 5, 6 and 7 outline the prevalence, aetiol- ogy, clinical presentation and treatment of keratotic Management of foot problems is an important, yet disorders, other skin conditions, nail disorders and often overlooked and undervalued component of peripheral vascular disorders, respectively. Chapters 8, geriatric health care. Even within podiatry, the profes- 9 and 10 are structured in a similar manner and focus sion entirely focused on the diagnosis and manage- on musculoskeletal disorders of the toes, forefoot and ment of foot disorders, treatment of older people is midfoot/rearfoot, respectively. Finally, Chapters 11 perceived by many to be less interesting and fulfilling and 12 provide additional information about the role than other areas of practice. Subsequently, there is a of footwear and foot orthoses in the management of paucity of literature pertaining to the management of these conditions. the older foot. While generalist geriatrics textbooks often include a short section on foot disorders, to my In defining the size and scope of this book, it has knowledge, there has not been an entire textbook been necessary to exclude or limit the coverage of published on this topic since Arthur Helfand’s some topic areas that are discussed in greater detail in Clinical Podogeriatrics in 1981. existing texts. For example, while this book discusses common skin conditions affecting the foot, the reader The objective of this book is to provide the reader is advised to supplement this information with a more with a comprehensive yet accessible review of the general dermatology textbook. Similarly, foot surgery epidemiology, aetiology, assessment and management

x PREFACE and foot orthotic prescription are discussed in the foot conditions is incomplete, some areas of the book context of the overall management of particular foot are more evidence-based than others. This is particu- conditions, but details regarding individual techniques larly evident in relation to many surgical procedures, are beyond the scope of the book. In limiting the the evidence of which is primarily derived from case- coverage of some of these topics, I do not wish to series studies. Hopefully, the recognition of the many give the impression that they are less important. In gaps evident in the literature will act as a catalyst for fact, the opposite is actually the case; by referring some readers to initiate clinical research projects to readers to other sources, I hope to ensure that they help address these shortcomings. are exposed to the appropriate level of detail that the topic deserves. I hope that this text will assist health-care profes- sionals in optimising the quality of care for older The book adopts an evidence-based approach to people with foot problems, ensuring that the addi- summarising the available literature, deferring to the tional years gained through our increased life expec- conclusions of systematic reviews and randomised tancy are as pain-free, active and fulfilling as controlled trials where such sources of information possible. are available. However, because our knowledge of the causes and best approaches to management of many Hylton B. Menz 2008

Acknowledgements I am indebted to several people who have assisted in with the scanning of radiographs and Lucy Shaw the completion of this book. First and foremost I assisted with preparing the clinical photographs. The would like to thank my wife, Elizabeth Barr, for her editorial staff at Elsevier, including Robert Edwards, generous support and encouragement during the Veronika Krcilova and Rebecca Gleave, provided writing process, even while she toiled away on her prompt and professional assistance from the initial PhD. I would also like to thank the many colleagues development of the book proposal through to the who provided me with access to their treasure trove final production of the book. of clinical photographs and allowed me to reproduce them in the book. Full photographic credits are pro- This book is dedicated to Dr Ramaswamy Ganapati, vided throughout the text; however I would like to Director of the Bombay Leprosy Project, Mumbai, particularly thank Dr Karl Landorf, Lloyd Reed, India, in recognition of his tireless and compassionate Lesley Newcombe and Felicity Prentice. work in improving the lives of people affected by leprosy. I encourage all readers of this text to support Dr Karl Landorf, Ivan Bristow, Mark Gilheany and the ongoing work of this not-for-profit organisation Nikki Frescos provided valuable suggestions on parts by making a donation at www.bombayleprosy.org. of the manuscript. Dr Shannon Munteanu assisted

Epidemiology of foot CHAPTER problems in older people 1 CHAPTER CONTENTS PREVALENCE OF FOOT PROBLEMS Prevalence of foot problems 1 It has long been recognised that foot problems are Studies conducted in aged care facilities and highly prevalent in older people and have a significant detrimental impact on an older person’s indepen- inpatient settings 2 dence and quality of life.1 However, the true epide- Studies conducted in outpatient settings 2 miology of foot problems in this population is difficult Community-based studies 3 to ascertain for several reasons. Firstly, in contrast to most common conditions affecting older people, Risk factors for foot problems 5 there is no consensus as to what actually constitutes Age 6 a foot ‘problem’. This is largely due to the fact that Sex 6 a very broad spectrum of musculoskeletal, dermato- Obesity 6 logical, vascular and neurological conditions may Co-morbidities 6 manifest in the foot, each requiring its own case defi- Income, education and ethnicity 7 nition. (In this chapter the terminology adopted by each individual study has been used.) Furthermore, Consequences of foot problems 7 the definition of a foot problem may also be broad- Mobility 7 ened to include difficulties in maintaining basic foot Falls and injuries 8 hygiene (such as cutting toenails) or difficulty pur- Health-related quality of life 8 chasing comfortable shoes.2 Summary 9 Secondly, while some prevalence studies rely on References 9 self-reporting of foot problems, others document the prevalence of foot problems based on clinical assess- ments. There are considerable discrepancies in preva- lence estimates between these two approaches, with those based on self-report generally revealing signifi- cantly lower rates of foot problems. Whether older people under-report foot problems or clinicians over- report them is difficult to determine; however, there is some evidence that many older people consider foot problems to be an inevitable accompaniment of ageing3 and therefore do not consider reporting them as medical conditions in health surveys.4 Subsequently, comparisons of foot problem prevalence between

2 EPIDEMIOLOGY OF FOOT PROBLEMS IN OLDER PEOPLE studies based on self-report and those involving clini- hospital inpatients aged over 65 years (admitted to cal assessments are problematic. either a geriatric or orthopaedic ward) reported that 50% had at least one foot problem, the most common The third major consideration when interpret- being calluses (40%), hallux valgus (20%) and lesser ing prevalence data on foot problems is the sample toe deformity (20%). Goniometric assessments also population. Most studies have been conducted on revealed that 70% had limited ankle motion, 40% had institutionalised older people, or on relatively small limited foot eversion and 15% had limited dorsiflexion convenience samples in a range of clinical settings. of the first metatarsophalangeal joint. Similar to the While such studies are useful and often provide findings of Ebrahim et al,7 only a small number of detailed information on a range of conditions, the patients (7%) reported foot discomfort. prevalence estimates derived from such studies cannot be considered representative of the broader older Although it is difficult to compare these studies population, because of inherent sampling bias. Very because of differences in study populations and assess- few well-designed epidemiological studies using rep- ment techniques, it is clear that hospital inpatients resentative random samples have been undertaken and older people residing in aged care facilities have and, while large-scale national health surveys do a high prevalence of foot disorders. In all four studies, provide representative data on medical conditions, women demonstrated a higher prevalence of foot few include detailed information on foot problems. problems than men. The unexpected observation of Therefore, establishing the prevalence of foot prob- a relatively low prevalence of foot symptoms in the lems in older people requires making a distinction two hospital-based studies7,8 highlights the aforemen- between non-representative clinical studies that tioned discrepancy in prevalence rates based on clini- provide considerable detail in a small number of cal assessments compared to self-report. However, the people and larger, representative epidemiological apparent discrepancy between observed foot condi- studies, which often lack clinical detail. tions and reported symptoms in institutionalised older people may simply reflect the confounding effect of STUDIES CONDUCTED IN AGED CARE limited mobility, i.e. many of the older people in these FACILITIES AND INPATIENT SETTINGS studies may not have been physically active enough to develop foot symptoms. One of the earliest studies to examine the prevalence of foot problems was conducted on 1011 nursing STUDIES CONDUCTED IN home residents (300 men and 711 women, aged OUTPATIENT SETTINGS 60–90 years) in the USA.5 A podiatrist undertook a visual inspection of each resident and completed a Several studies involving the review of patient records simple checklist. Although no overall prevalence from outpatient clinics have been conducted to figures were provided, the most commonly observed examine the epidemiology of foot problems. The conditions were corns (25%), hallux valgus (23%) and South Mountain Study conducted by Helfand et al9 calluses (14%), with women exhibiting a higher preva- in 1968 involved assessments of 551 people aged over lence of all foot conditions compared to men. 65 years who were attending a rehabilitation centre in the USA. The most common foot conditions diag- Subsequent studies in aged care facilities and hos- nosed by the attending podiatrists were hyperkerato- pitals have reported similar findings in relation to the sis (48%), dry skin (46%), thickened nails (42%) and most common foot problems but quite variable preva- hallux valgus (38%). Peripheral vascular conditions lence rates. Hsu et al6 assessed 426 older people were also common, with 44% of patients having an attending a hospital-based foot clinic in the USA and absent posterior tibial artery pulse. reported that 36% had nail and skin problems, 31% had circulatory problems and 21% had structural foot More recently, Plummer & Albert10 examined 308 deformities. A similar study conducted in the UK7 new referrals to an outpatient foot care service in a USA assessed foot problems in 100 hospital inpatients and health sciences centre over a 24-month period and found that 39% had lesser toe deformities, 30% had found that the prevalence of foot abnormalities corns or calluses and 29% had hallux valgus. Interest- increased significantly with age, with 45% of patients ingly, despite the high prevalence of these problems, aged 80–95 years exhibiting at least one foot abnor- only 19% complained of painful feet. Finally, a Hong mality. The key finding of this study was that older Kong study8 involving clinical assessments of 166 people without diabetes demonstrated a similar preva-

Prevalence of foot problems 3 lence of inappropriate foot-care practices and ill-fitting provided by large-scale epidemiological studies footwear to younger patients with diabetes, suggesting involving random sampling of participants, using that non-diabetic older people are at high risk for foot standardised definitions of various foot conditions. problems and should therefore receive similar foot- Unfortunately, very few such studies have been under- care screening and education to those with diabetes. taken with a specific focus on foot problems. In many cases, foot problem prevalence data is derived from By far the most extensive outpatient study on the national health surveys, which may only include a prevalence of foot problems is the Achilles Foot single question about foot problems (e.g. do you have Screening Project. This study commenced in 1997 problems with your feet?), or from chronic pain prev- and involved clinical examination of the feet of people alence studies, which request that the participant attending dermatologists or primary care physicians report the location of their pain. For the purpose of in Austria, Belgium, China, the Czech Republic, simplicity, foot problems or pain located in the foot Germany, Greece, Hungary, Israel, Italy, Luxem- are frequently combined with knee or hip disorders bourg, the Netherlands, Poland, Russia, Slovenia, and documented as ‘lower extremity problems’. South Africa, Sweden, Switzerland and the UK.11 The Therefore, in many studies it is difficult to delineate primary focus of this study was to determine the the prevalence of the foot problem itself. Despite prevalence of fungal infections affecting the foot, these limitations, these studies do provide more although information was also collected on other foot precise estimates of foot problem prevalence than conditions. Initial results from 13 695 people residing those conducted in clinical settings. in six of the participating European countries12 revealed that a clinical diagnosis of a foot disorder was Studies conducted in the USA made in 58% of patients, with a much higher preva- lence in those aged over 65 years (78%). The most Several community-based prevalence studies involv- commonly diagnosed conditions in older people were ing clinical assessments have been conducted in the onychomycosis (45%), tinea pedis (29%), pes planus USA. The Keep Them Walking project, conducted in (28%), plantar corns and calluses (26%) and hammer 1968, involved evaluations of 1366 older people toes (24%). A follow-up study involving 90 085 older attending a range of community centres and senior patients across all the participating European coun- citizen clubs.15 An extremely high prevalence of clini- tries13 reported that almost half had clinical evidence cally determined foot problems was reported (95%), of fungal foot infection. Lower prevalence estimates with 74% of participants reporting foot pain. However, in older people for tinea pedis (8%) and onychomy- these figures need to be viewed with some caution, as cosis (6%) were reported in the Hong Kong arm of no definitions of these foot complaints were provided the study,14 although the sample size was considerably and it is likely that the method of recruitment (talks smaller (824 participants). to senior citizen clubs delivered by a podiatrist and mail-out leaflets about foot problems) skewed the The main limitation with prevalence studies con- sample towards those with foot problems. A subse- ducted in outpatient settings is that of sampling bias, quent study in 1998 using very similar methods16 in that the characteristics of the sample population reported a foot problem prevalence of 84% in 417 studied reflects the geographical location of the clini- people, the most common conditions being foot pain cal service and the method by which the service is (45%), corns (33%), calluses (26%) and hallux valgus administered (such as the eligibility criteria to access (24%). the service). In particular, inclusion in the Achilles Foot Screening Project is clearly biased towards older The Dunedin Program, which commenced in people who have a pre-existing dermatological condi- 1975 as a hypertension screening study, involved the tion, as most assessments were performed in derma- administration of a questionnaire to 733 people aged tology clinics. As such, the prevalence of fungal foot over 65 in Dunedin, Florida, a popular retirement disease derived from this study is likely to be an area in the USA.17 The results indicated that 60% of overestimate. women and 32% of men were troubled by foot prob- lems. The most commonly reported conditions were COMMUNITY-BASED STUDIES toenail problems (22%), calluses (20%), corns (16%), dry skin (15%) and bunions (13%). Women reported The most accurate estimates of the prevalence of foot a higher prevalence of corns and bunions than men. problems in the general older population are ideally

4 EPIDEMIOLOGY OF FOOT PROBLEMS IN OLDER PEOPLE Similar figures for the prevalence of calluses (25%) and Table 1.1 Prevalence of foot problems (%) in bunions (17%) were reported by Gould et al,18 who older people in the USA according to sex conducted a survey of foot problems by administer- ing a questionnaire to 45 000 shoe stores across the Men Women Total USA. Dermatological conditions 74.8 59.3 65.2 The National Health Interview Survey (NHIS), Thickened nails* 46.0 37.0 40.4 undertaken by the USA Public Health Service, is a Elongated nails* 7.2 7.5 7.4 regular interviewer-administered survey of general Ingrown nails 45.7 65.9 58.2 health that includes questions on bunions, corns and Corns/calluses† 24.9 20.9 22.4 calluses, and toenail problems. In 1990, the NHIS Fungal infection 20.9 9.7 14.0 included an additional podiatry supplement with Cracks/fissures* 5.7 1.6 3.2 questions pertaining to foot infections, arthritis Maceration between toes* 15.3 12.8 13.7 and orthopaedic conditions.19 The 1990 NHIS Dry skin 7.9 1.9 4.2 involved interviews with 119 631 people and reported Ulcers/lacerations* a 31% prevalence of foot problems in respondents 34.5 aged over 65 years. The most commonly reported Orthopaedic conditions 37.3 32.8 33.4 problems were corns and calluses (11%), toenail prob- Hammer toe 29.4 35.9 lems (10%), bunions (5%) and foot infections (5%). Mallet toe 8.7 Shortly after the NHIS, a smaller telephone survey of Claw toe† 5.2 10.8 13.2 1003 people conducted by a marketing company Bunionette 14.0 12.7 15.6 reported very similar findings: an overall 38% preva- Overlapping toes 13.6 16.9 0.5 lence of foot problems in those aged over 65 and a Missing toes 0.2 0.8 37.1 similar breakdown of the most commonly reported Bunion† 25.3 44.3 0.7 conditions.20 Hammer toe (great toe) 0.8 0.6 0.7 Cock-up hallux 0.7 0.7 19.0 The Women’s Health and Aging Study is a longi- Flat feet 17.2 20.1 5.2 tudinal study of the causes of disability in 1002 High arch† 2.4 7.0 women aged over 65 years.21 An analysis of baseline 14.9 data revealed that 70% of the sample had bunions and Pain and tenderness 30.9 50% had hammer toes. A relatively small proportion of the sample reported ‘severe’ foot pain (14%), which Ankle joint pain 14.1 15.3 20.2 was defined as pain lasting 1 month or longer and rated 7 or above on a scale from zero to 10. Interest- Tenderness to palpation (any 26.0 33.9 16.8 ingly, there was no association between the presence 6.9 of foot deformities and severe foot pain. site) 4.2 11.6 The most recent community-based study to Tenderness: 17.9 21.7 focus on foot problems in the USA was the Feet First study, a detailed investigation involving a random metatarsophalangeal joints sample of 784 people aged over 65 in Springfield, Massachusetts.22 The location of the study was Tenderness: interstitial spaces 15.2 17.8 chosen because of its racial diversity in order to allow comparisons in the prevalence of foot problems to be Tenderness: plantar fascia 6.4 7.2 made between non-Hispanic white, Puerto Rican and African Americans. Overall, the most common Tenderness: plantar heel pad 3.9 4.3 conditions were toenail disorders (75%), lesser toe deformities (60%), corns and calluses (58%) and Tenderness: medial malleolus 9.0 13.2 bunions (37%). A summary of these findings accord- ing to sex is shown in Table 1.1. Toenail conditions, *men > women (p < 0.05). †women > men (p < 0.05) fungal infections, cracks and fissures, maceration between toes and ulcers or lacerations were more claw toes and high arches were more common in common in men, while bunions, corns and calluses, women. Studies conducted in the UK Several community-based studies of foot problems have been conducted in the UK for the purpose of determining foot health service provision needs in the National Health Service. In 1986, the Department of Health and Social Security funded a study involving

Risk factors for foot problems 5 a random sample of 543 people aged over 65 years.23 Foot Pain and Disability Index.30 As such, the figure Initially, participants completed a questionnaire that reported is likely to represent more severe foot pain asked whether they had a foot problem, and then 70% than other surveys. of the sample was assessed by a chiropodist. Half of the sample (52%) reported that they had foot prob- Studies conducted in other countries lems, while foot conditions were diagnosed in 84% of the sample by the chiropodists. The most common Although the majority of community-based studies problems reported were similar to previous studies have been conducted in the USA or UK, several (nail problems, corns and bunions), although the smaller studies have been undertaken in Australia and clinical assessments also revealed a high prevalence of in some European countries. orthopaedic disorders such as hammer toes and flat feet. In Australia, a mail-out questionnaire study4 con- ducted on 128 older people reported that 45% of men Subsequent studies have largely confirmed these and 59% of women suffered from painful feet, mostly findings, particularly in regard to the very high preva- affecting the toes. Other commonly reported prob- lence of foot conditions reported when foot care lems were nail disorders, corns and bunions. The specialists undertake the assessments. A study of 999 Health Status of Older People Project conducted in community-dwelling older people by Elton & 1994 was a community-based study of 1000 people Sanderson24 found that 71% were considered to have aged over 65, and found a 30% prevalence of self- a foot problem by the chiropodist, and White and reported ‘problems with feet or legs’.31 A more recent Mulley25 reported that, of 96 people aged over 80 prevalence study of lower extremity pain in 1486 years living in their own homes, only six were consid- older women reported that 34% experienced foot ered to have normal, healthy feet. However, consis- pain.32 tent with studies in clinical populations, a much smaller proportion reported symptoms (30%). Wessex Two community-based studies in Italy and the Feet,26 a foot health survey of 700 people (including Netherlands reported similar findings in relation to 200 aged over 65 years), reported a prevalence of the prevalence of self-reported foot pain. Benvenuti ‘foot problems’ of 62%, with calluses (42%), nail et al33 studied 459 people aged over 65 living in a problems (41%), corns (30%) and hallux valgus (27%) small Italian town and reported that at least one foot being the most commonly reported conditions in the symptom or sign was recorded in 83% of the sample, older group. with the most common conditions being calluses or corns (65%), thickened nails (30%) and hallux defor- More recently, four studies involving random mities (21%). Foot pain ‘when standing’ was reported samples of community-dwelling older people in the by 22% of the sample. A larger study of 7200 people UK have reported prevalence data on foot disorders. aged over 65 conducted in the Netherlands34 reported The Clifton Assessment Procedure for the Elderly a similar prevalence of 20% for self-reported foot study27 in Northern Ireland involved a questionnaire problems of more than four weeks’ duration. of 248 people aged over 65 years. Difficulty cutting toenails was the most commonly reported problem RISK FACTORS FOR FOOT PROBLEMS (96%), followed by corns (48%), hard skin (36%) and hallux valgus (12%). A larger community study con- Foot conditions in older people are generally chronic ducted in Wales28 involving clinical examinations of and have taken many years to develop, so it is unlikely 792 people aged over 60 years reported that 53% had that there will ever be a prospective, longitudinal three or more foot problems, the most common study to determine why some people develop foot being lesser toe deformities, corns and calluses. Finally, problems and others do not. Nevertheless, several of the Cheshire Foot Pain and Disability Survey29 of the previously discussed prevalence studies have 4780 people aged 18–80 years reported a relatively also evaluated the role of age, sex and co-morbidities low prevalence of foot pain in those aged over 65 in the development of foot problems, and such (approximately 13%); however, the case definition of cross-sectional data provides useful insights into which foot pain required that participants have current foot factors may influence the development of foot pain, pain lasting for at least 1 month, and have docu- symptoms. mented at least one disability item on the Manchester

6 EPIDEMIOLOGY OF FOOT PROBLEMS IN OLDER PEOPLE 16Prevalence (%) box. Heel elevation increases the pressure borne by Men the metatarsal heads,36–39 and it has previously been demonstrated that older people who wear shoes that 14 Women are too narrow or too short are more likely to have 12 corns, lesser toe deformities, hallux valgus and foot pain.40 However, the higher prevalence of foot pain 10 may also reflect sex differences in pain tolerance in general, since women are more likely to report mus- 8 culoskeletal pain and pain interference at other body regions.41 6 OBESITY 4 Several studies have reported an association between 2 body mass index (BMI) and foot pain in older people,21,31,32,34,35 although there is little evidence that 0 older people with overweight or obesity have a higher 18 – 24 25 – 34 35 – 44 45 – 54 55 – 64 65 – 74 75 – 80 prevalence of structural foot disorders. A plausible Age group explanation for the link between obesity and foot problems can be derived from plantar pressure studies. Figure 1.1 Prevalence of disabling foot pain (%) in the Several investigations have assessed the loading UK according to age and sex. patterns of the foot in obese and non-obese people and have demonstrated significant increases in force AGE and pressure under the foot when walking, particu- larly under the midfoot and metatarsal heads.42,43 The most obvious risk factor for the development of Over time, it is likely that these elevated forces will foot problems is advancing age, as prevalence studies overload plantar tissues and lead to the development involving participants across a wide age range have of conditions such as metatarsalgia44 and plantar heel consistently found that older people have much higher pain.45 rates of foot problems.19,26,29 However, there is some evidence of a non-linear relationship, in that the prev- Further evidence to support a causal relationship alence seems to increase until the age of approxi- between obesity and foot problems can be derived mately 65 years and decline thereafter (Fig. 1.1).26,29 from a recent study of 48 obese patients undergoing This is probably because of the confounding influence bariatric surgery. Prior to surgery, all patients reported of physical activity. As discussed previously in relation musculoskeletal complaints, with 50% reporting mus- to the lower rates of foot symptoms reported by insti- culoskeletal foot pain. 6–12 months following surgery tutionalised older people, it could be that the devel- (which resulted in an average weight loss of 41 kg), opment of foot symptoms requires a certain level of only 23% of patients reported musculoskeletal symp- weightbearing activity, so even older people with toms and only 4% reported foot pain.46 severely deformed feet may not develop symptoms if they lead a largely sedentary lifestyle. CO-MORBIDITIES SEX A wide range of co-morbidities are associated with the development of foot problems, such as diabetes,47 Sex has a clear influence on foot problems, with rheumatoid arthritis,48 stroke49 and systemic sclero- several studies indicating that women have a higher sis.50 These associations largely reflect the direct con- prevalence of foot conditions, particularly hallux sequences of the specific systemic disease process on valgus, corns and calluses,17,20,23,24,26,33 and are more the vascular, neurological, integumentary and muscu- likely to report foot pain.4,29,33–35 However, the Feet loskeletal structures within the foot. However, foot First study,22 which included a wider array of foot problems are more common in older people with conditions than most prevalence studies, found that, multiple chronic diseases21,31,34 or pain in other body although women were more likely to exhibit hallux regions21,29,32,35,51 and several recent reports have sug- valgus, corns and calluses, other conditions (nail con- ditions, fungal infections and ulcers) were more prev- alent in men. The most likely explanation for the higher prevalence of foot problems in women is the wearing of shoes with an elevated heel and narrow toe

Consequences of foot problems 7 gested that chronic foot pain in older people may be foot problems than non-African Americans.19,21 part of a generalised form of osteoarthritis or systemic However, only one study has focused on ethnic dif- pain syndrome. Leveille et al21 found that older ferences in clinically assessed foot problems. The Feet women with foot pain were more likely to have ankle First study22 specifically selected a multi-ethnic com- oedema and osteoarthritis affecting the knees or munity in Springfield, Massachusetts (including hands. Similarly, participants with foot pain in the Puerto Rican, non-Hispanic white and African Ameri- Cheshire Foot Pain and Disability Survey29 were more can residents) to investigate ethnic differences in foot likely to report pain in the shoulder, axial skeleton, problems. After adjusting for sex, Puerto Ricans were hip, knee and hands, and two recent studies reported far less likely to have toe deformities and sensory loss that while few structural foot conditions were associ- than non-Hispanic whites or African Americans, while ated with foot pain in older people, those with foot bunions and ankle oedema were more common in pain were more likely to report osteoarthritis or pain African Americans. The prevalence of pain was also in the spine, hips, hands or wrists.35,51 influenced by ethnicity, with Puerto Ricans more likely to report tenderness to palpation at any site on The role of psychological factors in the develop- the foot. Overall, ethnicity influenced foot problem ment of foot pain has been suspected for some time52 prevalence more than education levels. and two studies have reported that older people with foot problems are more likely to report depression.31,51 As with many other health conditions, ethnic dif- Although it is possible that the depression is a conse- ferences in the prevalence of foot problems are likely quence of foot pain rather than a causative factor, to reflect a range of historical, cultural and socioeco- there is emerging evidence from studies of chronic nomic factors that influence lifestyle and access to generalised musculoskeletal pain that various forms of health care, rather than genetic susceptibility.55 Fur- psychological distress may precede the development thermore, the racial groupings used in epidemiologi- of symptoms.53 Furthermore, it has been shown that cal studies are inconsistent,56 which makes direct people with severe mental illness (including schizo- comparisons between studies extremely difficult. phrenia, major depression and bipolar disorder) have a significantly higher prevalence of foot pain than the CONSEQUENCES OF FOOT PROBLEMS general population.54 Prospective studies are required to confirm whether a cause and effect relationship MOBILITY between psychological factors and foot pain does indeed exist. The foot provides the only direct source of contact with the supporting surface during weightbearing INCOME, EDUCATION AND ETHNICITY activities, so it reasonable to expect that foot problems could have a detrimental effect on mobility in older Despite the general consensus that health status is people. Several investigators have directly questioned strongly linked to sociodemographic factors, the role older people as to whether their foot problems inter- of education and income in the prevalence of foot fered with daily activities. White & Mulley25 inter- problems in older people is equivocal. While some viewed 106 people aged over 80 years and reported studies have reported that older people with foot that 34% of those with foot pain felt that their foot problems have a lower level of income,19 others have pain prevented them from walking. Similarly, studies failed to find such an association.31,32 Similarly, lower of community dwelling people aged over 65 years by levels of education have been found to be associated Black & Hale17 and Cartwright & Henderson23 found with foot problems in some studies19,31 but not that many older people attributed their limited activ- others.21,32,34 These discrepancies are likely to reflect ity to foot problems. Significant associations between differences in how income levels are defined, differ- the presence of foot problems and foot-related func- ences in educational systems between countries and tional limitation,57 self-reported disability58 and inabil- variability in adjustment for confounders in the statis- ity to perform activities of daily living33,34,59 (such as tical models. housework, shopping and cooking) have also been reported. The influence of ethnicity on foot problem preva- lence has received little attention in the literature. Other studies have explored this relationship by Two community-based studies in the USA have found conducting physical assessments in people with and that African Americans report a higher prevalence of

8 EPIDEMIOLOGY OF FOOT PROBLEMS IN OLDER PEOPLE without foot problems. An evaluation of gait patterns fourfold increased risk of falling. Tinetti et al69 found in 459 older people by Benvenuti et al33 revealed that that the presence of a ‘serious foot problem’ (defined those with foot pain required a greater number of as a moderate to severe bunion, toe deformity, ulcer steps to walk 3 m than those free of foot problems. A or deformed nail) doubled the risk of falling in 336 similar study of 1002 older women21 found that those people aged over 75 years after adjusting for socio- with chronic and severe foot pain walked more slowly demographic characteristics, psychological factors and and took longer to rise from a chair, while Barr et al31 medication use. A prospective study of 979 people found that self-reported foot or leg problems were aged over 70 years in Finland found that older people significantly associated with impaired performance on with bunions were twice as likely to fall than those the Timed Get Up and Go test (a timed mobility test without.70 Follow-up results from the Women’s that involves rising from a chair and walking 6 m). Health and Aging Study of 1002 women aged over Finally, a recent study found that an overall measure 65 years found that foot pain was the only site of pain of foot impairment was significantly associated with that was significantly associated with falls.71 impaired performance in tests of balance (including postural sway and leaning tests) and functional ability The most recent prospective study of foot prob- (including stair walking and rising from a chair).60 lems and falls72 assessed a wide range of foot and ankle characteristics (including foot posture, range of FALLS AND INJURIES motion, deformity, lesions, tactile sensation, toe strength and pain) in 175 retirement village residents. The association between foot problems and falls has During the 12 month follow-up period, 71 (41%) been suspected for some time. In 1958, DeLargy61 reported falling and, compared to those who did not hypothesised that decreased activity associated with fall, fallers demonstrated decreased ankle flexibility, foot problems in older people could lead to the devel- more severe hallux valgus deformity, decreased plantar opment of muscle weakness, thereby predisposing to tactile sensitivity, decreased toe plantarflexor strength falls. In contrast, Helfand62 argued that painful lesions and a higher prevalence of disabling foot pain. and structural foot deformities could directly lead to a fall by detrimentally altering the foot’s functional In addition to falls, a recent study has suggested base of support. As discussed in the previous section, that foot problems may also increase the risk of auto- there is now sound evidence that various foot charac- mobile accidents in older people. A prospective cohort teristics are significant independent predictors of study of 283 people aged over 72 years by Marottoli balance and functional ability, and there is emerging et al73 found that those with three or more foot prob- evidence that foot problems are also a risk factor for lems (including nail problems, calluses, bunions and falls. hammertoes) were twice as likely to have been involved in an automobile accident during the 12 month Studies of falls risk factors can be divided into two follow-up period. This association remained signifi- categories: retrospective studies, in which older peo- cant after adjusting for several possible confounding ple’s history of falling (usually in the past 12 months) variables related to physical performance, suggesting is documented and comparisons made between fallers that foot problems may increase the risk of auto- and non-fallers; and prospective studies, in which foot mobile accidents by interfering with the ability to characteristics are measured at baseline and the inci- manoeuvre between the accelerator and brake dence of falls is determined by following participants pedals. over a 12 month period. Six retrospective studies have shown that older people who suffer from foot prob- HEALTH-RELATED QUALITY OF LIFE lems are more likely to have fallen in the previous 12 months.31,60,63–66 However, retrospective studies are Quality of life in older people is strongly associated limited because of the questionable accuracy of recall with the ability to independently undertake physical of falls by older people67 and difficulties in determin- tasks free of pain and, as such, musculoskeletal condi- ing a causal relationship. tions are a major cause of disability and reduced quality of life in this population. Several recent studies Five prospective studies have now confirmed have indicated that foot problems have a detrimental that foot problems are a falls risk factor. A study of impact on self-reported measures of physical, mental 100 men aged 65–85 years by Gabell et al68 reported and social function. Using the Medical Outcomes that undefined ‘foot problems’ was associated with a Study Short Form 36 (SF-36) questionnaire in a com-

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Physiological changes CHAPTER in the ageing foot 2 CHAPTER CONTENTS The foot undergoes significant structural and functional changes with advancing age. While many Integumentary system 13 of these changes merely reflect the physiological Epidermis and dermis 14 alterations in tissues elsewhere in the body, some Nails 15 changes are more pronounced than those that occur Functional implications 15 in other body regions, while others are unique to Plantar soft tissues 15 the highly specialised loadbearing structures of the foot. Indeed, it has been argued that careful assess- Peripheral vascular system 16 ment of the older foot can provide useful clinical Arteries 16 insights into systemic conditions yet to be clearly Capillaries 17 manifested elsewhere.1 The following chapter reviews Veins 17 the body of literature pertaining to age-related changes Functional implications 17 of the foot in relation to the integumentary system, the soft tissue structures, the peripheral vascular and Peripheral sensory system 17 sensory systems, the skeletal system and the muscular Functional implications 18 system, and discusses the functional implications of these changes. Skeletal system 18 Bone 18 INTEGUMENTARY SYSTEM Joints 18 Tendon and ligament 19 The integumentary system consists of the skin, nails Functional implications 20 and subcutaneous tissues. The primary functions of this system are to provide a barrier between the Muscular system 20 20 body and its surrounding environment, to provide Age-related changes in muscle tissue sensory information and to assist in the regulation Ankle muscles 21 of body temperature. Normal ageing is known to Foot muscles 21 affect the structure and function of each of the com- Functional implications 22 ponents of the integumentary system, which often manifest as characteristic changes to the appearance Summary 22 of the foot.2 These changes are summarised in Table References 22 2.1 and are described in more detail in the following section.

14 PHYSIOLOGICAL CHANGES IN THE AGEING FOOT Table 2.1 Summary of major age-related physiological changes to the integumentary system Age-related changes Implications Skin ↑ dryness of skin → fissuring and hyperkeratosis ↓ production and turnover of keratinocytes ↑ risk of infection ↓ density of sweat glands ↓ wound healing ↓ number of Langerhans cells ↑ wound dehiscence ↓ number of dermal collagen and elastin fibres ↑ bruising ↑ thickness and stiffness of dermal collagen fibres ↓ capillary loops in papillary dermis ↑ time required to treat nail infections ↑ rate of re-infection Nails ↓ nail growth rate (up to 50% reduction) ↑ peak pressures under forefoot → metatarsalgia ↑ nail plate thickness Development of plantar heel pain Plantar soft tissues Distortion and rupture of septa ↓ compressibility ↑ stiffness ↑ energy dissipation EPIDERMIS AND DERMIS keratinocytes may reduce to only 50% of that of a young person.13 Because of this delay in turnover The skin of the sole of the foot has several unique time, the moisture content of keratinocytes is reduced, features. Most notably, plantar skin is hairless and, which, combined with the reduction in sweat gland although it contains a high density of eccrine sweat density,14 contributes to the dry, scaly appearance of glands, it has no sebaceous glands.3 The plantar epi- elderly skin.7,8 Langerhans cells, which play an impor- dermis is considerably thicker (approximately 1.5 mm tant role in the immune function of the epidermis, thick, compared to 0.1 mm in other regions of the decrease dramatically with age,15 resulting in a reduced body) and demonstrates a pattern of ridges that assist rate of sensitisation to microorganisms.16 in generating sufficient friction when standing and walking barefoot. The plantar dermis is approximately In contrast to the epidermis, the dermis undergoes 3 mm thick and is penetrated by adipose tissue, which a significant reduction in thickness due to a marked provides resilience to shear stresses.3,4 Plantar skin is loss of collagen fibres.17 The collagen fibres that also highly adaptable, as evidenced by the consider- remain become thicker and stiffer and undergo a hap- ably thicker epidermis and dermis observed in people hazard cross-linking process.7,18 Elastin fibres, which who do not wear shoes.5 Because of this adaptability, provide the skin with its elasticity, decrease in number it is sometimes difficult to delineate age-related and become fragmented.19,20 These processes alter the changes from the effects of weightbearing activity and mechanical properties of the skin, leading to increased footwear. fragility and loss of elastic recoil. Dermal macrophages and mast cells, which provide the second line of Advancing age is associated with several significant immune defence after epidermal Langerhans cells, changes to the structure and function of the skin at reduce in number with advancing age, lowering the both the epidermal and dermal levels.2,6–9 The thick- speed and intensity of the inflammatory response to ness of the epidermis does not change appreciably infection.16 with age;10 however, the dermal–epidermal junction becomes flattened, which may give the impression of Another factor that contributes to the impaired atrophy.11 In the foot, there may be an increase in inflammatory response in older people is the age- epidermal thickness due to thickening of the stratum related decline in cutaneous microvascular function. corneum associated with plantar calluses.12 The shape Older people exhibit a significant reduction in the and size of epidermal keratinocytes becomes more number of capillary loops in the papillary dermis, variable, and the rate of production and turnover of increased porosity of endothelial cells and a thickened

Integumentary system 15 basement membrane, all of which contribute to a less increase the time required to successfully treat these efficient superficial blood supply.13,21–23 It has been infections.2 demonstrated that a 70-year-old may have up to 40% less blood supply to the skin than a 20-year-old,24 and Wound healing is significantly delayed in older these age-related changes appear to be particularly people, because of both a reduction in wound con- pronounced in the lower limb. One of the most traction (a direct result of collagen cross-linking and obvious manifestations of this change is a progressive diminished elastin content of the dermis) and a reduction in skin surface temperature extending dis- reduced rate of epithelialisation and angiogenesis.32–34 tally from the groin.25 Even if a wound successfully heals, the tensile strength at the wound site is diminished, which increases the NAILS likelihood of dehiscence. Subsequently, wounds in older people often require much longer periods of Nails are comprised primarily of keratin produced by treatment and frequently recur. Bruising is also more the nail matrix, with a small contribution from the likely to occur because of the decreased integrity of underlying nail bed.26 Compared to fingernails, toe- superficial blood vessels leading to leakage of red nails are thicker (1.65 versus 0.60 mm) and have a blood cells into the papillary dermis.2 slower linear growth rate (1 mm/month versus 3 mm/month).27,28 With advancing age, the rate of Age-related changes in the structure and function growth of the nails decreases by up to 50%,29,30 be- of the nail have important implications for the man- cause of both a reduction in the turnover rate of agement of fungal nail infections (onychomycosis), keratinocytes and a reduction in size of the nail matrix one of the most common foot problems in older itself. This process is particularly pronounced in toe- people.35 Because of the reduction in nail growth rate nails, possibly because of the greater age-related and subsequent thickening of the nail plate, treatment decline in blood supply to the feet compared to the of onychomycosis with either oral or topical agents hands.28 may take considerably longer in older people and the possibility of reinfection is much higher.36 In addition to decreased rate of growth, the chemi- cal composition, histology and structure and appear- PLANTAR SOFT TISSUES ance of the nail plate changes with age. Older nails exhibit an increase in calcium and reduction in iron The sole of the foot has highly specialised soft tissue content, increased size of keratinocytes and degenera- structures in the heel and metatarsal head regions that tion of elastic tissues beneath the nail bed.28 The for- are designed to absorb impact forces associated with mation of longitudinal grooves and an overall increase weightbearing activities. Ageing is known to influence in thickness (onychauxis), often leads to a marked loss both the structure and function of these tissues and, of translucency,2,27 while periods of arrested growth although the literature is inconsistent, there is emerg- due to periods of systemic illness may also manifest as ing evidence that these changes may be associated transverse ridges known as Beau’s lines.27 These with the development of symptoms. changes are exacerbated by the presence of arterial insufficiency and low-level chronic trauma from ill- Metatarsal pads fitting footwear.27,28 The plantar tissues of the forefoot serve numerous FUNCTIONAL IMPLICATIONS functions, including anchoring the skin to the under- lying bony architecture of the foot, protecting under- The physiological changes in the integumentary lying flexor tendons, blood vessels and nerves, and system that occur with ageing have important func- attenuating both vertical and shear forces applied tional implications. As stated previously, the decreased during gait.37 The latter function is achieved by spe- water content of keratinocytes and decreased density cialised pads of fat cells under each metatarsal head of eccrine glands leads to an overall drying of the skin, confined by retinacula extending from the dermis to which predisposes to the development of hyperkera- the sides of each flexor tendon sheath.4 The metatarsal tosis and fissuring. The reduction in epidermal and pads progressively decrease in thickness from the first dermal immune function increases the risk of infec- to fifth metatarsal heads38–40 and undergo compres- tion31 and the reduced rate of epidermal turnover may sion of 10–15% when standing40 and up to 46% during gait.41

16 PHYSIOLOGICAL CHANGES IN THE AGEING FOOT Although atrophy of metatarsal padding is fre- Functional implications quently observed in older people, no studies have confirmed this finding using imaging techniques. Fur- The functional implications of the changes in plantar thermore, no histological studies have been under- soft tissues associated with ageing are unclear. While taken to ascertain whether ageing is associated with a atrophy of the metatarsal fat pads has been suggested breakdown of the connective tissues of the plantar to be a contributing factor to the development of forefoot. However, comparisons of the mechanical forefoot pain, a recent study using ultrasound mea- properties of metatarsal pads in young and older surements found no differences in the thickness of people by Hsu et al42 and Wang et al38 have demon- metatarsal pads in those with and without metatarsal- strated that older pads demonstrate greater stiffness, gia.49 However, it is likely that the mechanical proper- dissipate more energy when compressed and are ties of the fat pads are more relevant than their slower to recover after the load is removed, all of thickness, as it has been shown that the peak pressure which are likely to impair the ability of the forefoot under the metatarsal heads during gait is greater in to attenuate forces when walking. people with forefoot symptoms.50 Similarly, while research findings related to the role of heel pad thick- Heel pad ness in the development of heel pain are equivo- cal,51–53 it appears that painful heel pads are less The heel pad consists of a 13–21 mm thick layer of compressible and dissipate more energy.51,53 Further connective tissue, the deepest portion of which is studies utilising dynamic measurements of plantar soft firmly adhered to the plantar periosteum of the calca- tissues are therefore required to confirm the suspected neus by a series of dense fibrous septa containing association between ageing soft tissues and foot closely packed fat cells.4 In response to loading, these pain. fat cells flow within the individual chambers, and it is this mechanism, along with the elastic properties of PERIPHERAL VASCULAR SYSTEM the septa themselves, that provides the heel pad with its shock attenuation capability.43 ARTERIES Evaluations of cadaver heel pads indicate that, with The arterial wall consists of three layers. The inner- advancing age, the collagen fibres within the septa most layer, the intima, is composed of endothelial increase in number and size and appear more frag- cells, which provide a smooth surface for the passage mented. As a result, the septa may become distorted of blood, supported by a meshwork of collagen and and rupture, leading to a leakage of fat cells.44 elastin fibres. The middle layer (media) of large arter- However, this process does not lead to an overall ies consists mostly of elastin and provides vessels with decrease in the unloaded thickness of the heel pad; the ability to expand and contract in response to indeed, there is some evidence that older heel pads changes in blood flow volume. In contrast, the media are slightly thicker than those of younger people.45–47 of small arteries is largely made up of smooth muscle. Rather, the functionally important age-related differ- The outermost layer (adventitia) is primarily loose ences relate to how the heel pad responds to applied connective tissue, which assists in flexibly anchoring loads. Kinoshita et al48 used a drop-testing apparatus the vessel to surrounding structures. that applied a 5 kg mass to the heels of 10 young and 20 older people at two impact velocities. At the faster A summary of age-related changes in the peripheral impact velocity (0.94 m/s), the older heel pads dem- vascular system is provided in Table 2.2. Normal onstrated less deformation and greater energy dissipa- ageing does not appear to affect the structure or func- tion. In a study using ultrasound measurements of the tion of the adventitia; however, considerable changes heel pad in response to vertical loading, Hsu et al46 take place in the intima of all vessels and the media found that, while the unloaded heel pads of older of large arteries. For reasons that are still unclear, the people were slightly thicker, they demonstrated less size and shape of endothelial cells become more irreg- compressibility than the younger subjects when a 3 kg ular, and the overall thickness of the intima and media load was applied. Evaluation of stress–strain curves increases as a result of collagen cross-linking and inva- indicated that older subjects’ heel pads were also sion of smooth muscle cells.54–56 Elastin fibres in the slightly stiffer and dissipated more energy. media of large arteries break down and stiffen, result-

Peripheral sensory system 17 Table 2.2 Summary of major age-related decrease slightly from the age of 60 years and the physiological changes to the peripheral velocity of blood flow within them steadily declines vascular system from the age of 50 years.63 Advancing age is also sig- nificantly associated with perforator vein incompe- Age-related changes Implications tence,64 which may result from the accumulation of collagen fibres around valves. ↑ collagen cross-linking ↓ skin temperature ↑ thickness of intima and ↑ risk of peripheral FUNCTIONAL IMPLICATIONS media arterial disease The overall decline in peripheral vascular function in ↑ stiffness of arterial ↑ risk of venous older people clearly manifests in the foot. Even in the absence of overt vascular disease, many older people walls insufficiency complain of cold feet and exhibit dry, flaky skin, par- ↑ capillary wall thickness ticularly on the dorsum of the foot and the toes. As stated in the section on the integumentary system, → reduced blood flow peripheral vascular changes contribute to delayed ↓ diameter of veins wound healing and increased risk of infection. Fur- thermore, although the development of peripheral Development of perforator vein incompetence arterial disease is multifactorial, age itself has been shown to be an independent risk factor, with an ing in a reduction in elastic recoil, a reduction in approximate twofold increase in risk for every 10-year overall flow and an elevation in blood pressure.57 increase in age.65 Age is also an independent risk These age-related changes appear to be most pro- factor for conditions associated with venous insuffi- nounced in the lower limb. For example, pulse trans- ciency, such as varicose veins66,67 and venous ulcers,68 mission times (a measure of arterial stiffness) decrease which commonly affect the foot and ankle. by 1.6 ms/year in the toes compared to 0.6 ms/year in the fingers58 and vasodilation in response to occlu- PERIPHERAL SENSORY SYSTEM sion decreases by 7% per decade in the calf compared to 4% per decade in the forearm.59 The key components of the peripheral sensory system are the sensory neurons, which consist of a nerve cell CAPILLARIES body, branch-like extensions called dendrites and an elongated axon that extends from the nerve cell body, Capillaries are often less than 1 mm in length and and a range of sensory receptors, which are located in consist of a single layer of endothelial cells supported the skin and detect a range of stimuli, including vibra- by a basement membrane. The primary role of capil- tion, pressure and temperature.69 In particular, the laries is the exchange of oxygen from red blood cells glabrous skin on the sole of the foot contains large to surrounding tissues and absorption of waste mate- populations of mechanoreceptors capable of detect- rial. With advancing age, capillaries become even nar- ing the site, velocity and acceleration of mechanical rower and their porous walls increase in thickness, stimuli.69–71 because of basement membrane thickening and col- lagen deposition.60 As a result of these changes, ageing A summary of age-related changes in the peripheral is associated with an overall reduction in capillary sensory system is provided in Table 2.3. With advanc- blood flow, particularly in the lower limb.61,62 ing age, there is a generalised decline in the size and number of axons, and the myelin sheaths surrounding VEINS the axons undergo significant deterioration, leading to a reduction in nerve conduction velocity.72 Merkel Veins have the same basic structure as small arteries discs and free nerve endings are not affected by age; but are larger in diameter and exhibit considerably however, Meissner and Pacinian corpuscles consider- thinner walls. Relatively little is known about the ably reduce in density and the receptors that remain effects of age on the microstructure of veins and no exhibit a number of morphological alterations.73 As a studies have directly evaluated the effect of age on structure and function of foot veins. However, the diameter of the femoral veins has been shown to

18 PHYSIOLOGICAL CHANGES IN THE AGEING FOOT Table 2.3 Summary of major age-related SKELETAL SYSTEM physiological changes to the peripheral sensory system BONE Age-related changes Implications Bone cells produce two types of tissue: cortical bone, which consists of long tubes of bone matrix (called ↓ size and number of ↓ tactile and vibration osteons) forming the outer layer of the bone, and axons → ↓ nerve sensitivity trabecular bone, an irregular matrix that forms the conduction velocity central core of the bone. Cortical bone comprises ↓ proprioception and approximately 90% of the skeleton and is found pri- Deterioration of myeline kinaesthesia marily in long bones. Both types of bone are in a sheaths continuous process of remodelling, because of a cou- ↓ balance pling between bone formation by osteoblasts and ↓ density of Meissner and ↓ walking speed and bone resorption by osteoclasts. This process enables Pacinian corpuscles bone to respond to changing mechanical and meta- stability bolic demands.109 ↑ risk of falls ↑ likelihood of undetected A summary of age-related changes in the skeletal system is provided in Table 2.4. Age-related changes tissue damage in the physiology and biochemistry of bone cells are complex and only partly understood; however, it is result of changes in receptor structure and function, thought that ageing primarily affects the structure and ageing is associated with significant reductions in function of bone marrow, from which cellular precur- tactile sensitivity,74–77 spatial acuity78–81 and vibration sors to osteoblasts and osteoclasts are formed. This sense,74,77,82–85 and these changes are particularly pro- results in reduced osteoblastic activity, and subse- nounced in the lower limb compared to the upper quently the amount of bone formed is not equivalent limb.79,82,86 to the amount of bone resorbed.110 Bone mass there- fore undergoes a characteristic trajectory throughout Proprioception (the ability to detect the position the lifespan, with steady increases in bone density of body parts) and kinaesthesia (the ability to detect throughout adolescence, a plateau between the third movement of body parts) rely partly on skin receptors and fifth decade and a progressive decline thereaf- but also on Golgi tendon organs and receptors in ter.111 In men, age-related bone loss occurs at a rate muscle spindles.87 As with other mechanoreceptive of approximately 5% per decade,112,113 whereas women abilities, ageing is associated with significant decline experience a more rapid loss (approximately 10% per in proprioception and kinaesthesia in the sagittal decade) from the onset of menopause.114 From the plane of the knee76,88–91 and the sagittal92–95 and frontal age of 75 years, bone loss slows to approximately 3% plane96 of the ankle. per decade.112–114 Possibly in response to these changes in bone density, older people’s bones (both cortical FUNCTIONAL IMPLICATIONS and cancellous) also demonstrate a higher proportion of microfractures.115 When standing and walking, the sole of the foot pro- vides the only direct contact with the ground and JOINTS therefore provides important sensory information about the supporting surface.97 Furthermore, ankle Although the alignment and morphology of lower proprioception plays an important role in maintaining limb joints differ considerably depending on their balance when walking on irregular terrain. Subse- function, the basic structure is essentially the same. quently, age-related changes in peripheral sensation Each of the bones comprising the joint is covered are associated with deficits in balance 98–103 and walking with a thin layer of articular cartilage. The space speed,104,105 and reduced peripheral sensation is an between the bones, the joint cavity, is lined by a important risk factor for falls.106,107 Loss of plantar synovial membrane, which secretes synovial fluid, sensation in older people may also result in pressure enabling smooth movement of one bone over the from ill-fitting footwear or foreign bodies within the other. Encasing the synovial membrane is the joint shoe being undetected, leading to tissue damage and capsule, which consists of strong but flexible collagen ulceration.108

Skeletal system 19 Table 2.4 Summary of major age-related physiological changes to the skeletal system Age-related changes Implications Bone ↑ risk of osteoporosis ↓ osteoblastic activity ↑ risk of traumatic and insufficiency fractures ↓ bone density Joints ↑ risk of osteoarthritis ↑ collagen cross-linking of cartilage ↓ joint range of motion ↓ water content of cartilage ↓ balance ↑ stiffness of synovial membrane and joint capsule ↑ risk of falls ↓ production of synovial fluid ↑ risk of posterior tibial tendon dysfunction Tendon and ligament ↑ risk of tendon rupture when performing non-sporting ↑ collagen fibril concentration, diameter and cross-linking ↓ water content of glycosaminoglycans activities ↑ lipid content fibres, and binding the entire joint together are liga- With ageing, this protective mechanism becomes less ments, which are also primarily composed of collagen effective, and the joint may be in a state of constant fibres. loading.119 Much of the research relating to age-related In addition to these changes in cartilage structure changes in joints has focused on cartilage, because of and function, ageing also results in a stiffening of the its role in the development of osteoarthritis. Cartilage synovial membrane and a reduction in its ability to is a dense connective tissue comprising cells (called produce synovial fluid. As with ageing cartilage, there chondrocytes) dispersed in a matrix of various types is a reduction in the amount of chondroitin sulphate of collagen, proteoglycans and other matrix proteins, in the synovial fluid,120 which may influence its viscos- and water. The matrix provides cartilage with the ity. Collagen cross-linking also results in a shortening ability to withstand compressive, tensile and shear and stiffening of the joint capsule and supporting forces generated during movement. Degradation of ligaments.121 cartilage is a complex process influenced not only by age but also nutrition, individual mechanical joint TENDON AND LIGAMENT characteristics and level of physical activity. Further- more, it is difficult to delineate age-related changes The primary function of tendons is to transmit muscle from those associated with osteoarthritis. force to the skeletal system, whereas the function of ligaments is to bind bones together and restrict exces- Nevertheless, several changes in articular cartilage sive movement. Despite this difference in function, do appear to be related to the ageing process. At the the structure of tendons and ligaments is similar – molecular level, there is a gradual reduction in the both structures consist primarily of collagen fibrils amount of chondroitin sulphate and oligosaccharides, embedded in a matrix of proteoglycans. Evaluating and a corresponding increase in keratan sulphate.116 the effect of ageing on the structure of human tendons Collagen fibril width and cross-linking increase with and ligaments, however, is inherently difficult because age, and the water content decreases.117 Somewhat of the need to biopsy tissue. As a consequence, surprisingly, the cell content and thickness of articular much of our knowledge regarding the biochemical cartilage does not appear to change appreciably with and histological changes in these structures stems age,118 and joint surfaces in older people may be more from animal models (most commonly rat tails or the congruent than those of younger people. The latter Achilles tendons of rabbits), cadavers, or tendons observation has been explained by the notion that and ligaments harvested from surgical cases.122 some level of incongruence is a normal feature of a These investigations have revealed that advancing healthy joint, in order to provide access of synovial age results in significant increases in collagen fibril fluid to the cartilage and allow for controlled loading.

20 PHYSIOLOGICAL CHANGES IN THE AGEING FOOT concentration123 and diameter,124 and increased tion–adduction motion of the ankle joint complex. spacing and cross-linking of collagen molecules,125 Of particular note, women generally exhibited greater factors thought be indicative of non-enzymatic glyco- range of motion than men but also demonstrated sylation. Non-collagenous components of tendon greater reductions in ankle dorsiflexion and eversion have also been shown to undergo changes with age, with age. More recently, Scott et al143 showed that with decreases in the water content of glycosamino- older people had significantly less range of motion at glycans126 and increases in lipid content.127 the ankle joint (36° versus 45°, using a weightbearing lunge test) and less passive range of motion the first A small number of studies have directly evaluated metatarsophalangeal joint (56° versus 82°, measured structural changes in the human Achilles tendon. non-weightbearing) compared to younger controls. Snow et al128 analysed gross anatomy and histological Assessment of foot posture also indicated that sections of Achilles tendons obtained from neonatal, older people had significantly flatter feet, as in- young and old cadavers, and reported a progressive dicated by a higher foot posture index and arch index, reduction in the number of fibres connecting the and a reduction in the height of the navicular tendon to the plantar fascia with advancing age. In tuberosity. the older group, a band of periosteum clearly sepa- rated the insertion of the Achilles tendon and the Reduction in joint range of motion in the foot is plantar fascia. Using light and electron microscopy, strongly associated with impaired balance and func- Strocchi et al129 evaluated 15 cadaver Achilles tendons tional ability144,145 and increases the risk of falls,145,146 up to 87 years of age and reported that ageing was while the progressive flattening of the arch may pre- associated with a decrease in the diameter but an dispose to the development of posterior tibial tendon increase in the concentration of collagen fibrils. Similar dysfunction, a disorder in which the tendon becomes results were reported by Sargon et al130 in 28 Achilles progressively weakened and elongated, resulting in a tendon specimens obtained from patients undergo- painful flatfoot deformity.147 There is also emerging ing heel surgery. Finally, using magnetic resonance evidence that restricted range of motion in the ankle imaging, Magnusson et al131 demonstrated that older joint may impair the function of the calf muscle pump, women have a larger Achilles tendon cross-sectional thereby contributing to the development of venous area than younger women, reflecting the age-related disorders of the lower limb.148,149 hypertrophy evident in animal studies. Finally, despite having a reduced overall risk of FUNCTIONAL IMPLICATIONS tendon rupture because of their reduced exposure to ballistic activities, older people have an increased risk The functional implications of an ageing skeletal of tendon rupture when performing non-sporting system are considerable. Changes in bone density are activities, possibly due to age-related increases in strongly linked to the development of osteoporosis, tendon stiffness.150,151 the prevalence of which increases exponentially with age.132 Although the most serious consequences of MUSCULAR SYSTEM osteoporosis are vertebral, femoral and radius frac- tures, insufficiency fractures of the foot may also AGE-RELATED CHANGES occur, most commonly in the metatarsals133–135 but IN MUSCLE TISSUE also in the calcaneus136 and talus.137 Such fractures are frequently misdiagnosed and often lead to impaired Muscle fibres consist of elongated actin and myosin mobility. Ageing is also a significant risk factor for filaments encased in a tubular membrane. Broadly osteoarthritis,138 which affects the first metatarso- speaking, two types of fibre have been identified: phalangeal joint of the foot in 44% of people over the type I fibres, which contract slowly and can stay con- age of 80 years.139 tracted for long periods of time before fatiguing, and type II fibres, which contract more quickly but also Changes in joint tissues may also be responsible for fatigue more easily. One of the most characteristic the reduced range of motion of lower extremity joints features of advancing age is the inevitable reduction in older people. Several studies have shown that ankle in the total mass of muscle fibres, often referred to as dorsiflexion–plantarflexion range of motion reduces sarcopenia (adapted from the Greek, meaning ‘poverty with age140–142 and Nigg et al141 have also noted a of the flesh’).152,153 Muscle mass accounts for 40% of significant reduction in inversion–eversion and abduc-

Muscular system 21 Table 2.5 Summary of major age-related ANKLE MUSCLES physiological changes to the muscular system As stated above, most studies addressing age-related Age-related changes Implications differences in strength have examined quadriceps muscles; however, some have focused on ankle ↓ total muscle mass ↓ ankle dorsiflexion and muscles. One of the earliest studies to assess age-asso- ↓ muscle cross-sectional plantarflexion strength ciated changes in ankle muscle function was that of McDonagh et al,163 who compared ankle plantarflexor area ↓ toe plantarflexion strength in young and older men and reported that ↓ size of Type II fibres strength the maximum voluntary contraction in older subjects Development of large, was 20% weaker than in young subjects. A comparison ↓ balance of these results with those of arm flexor strength sug- slow-twitch motor units ↓ walking speed gested that ankle plantarflexors were more signifi- ↑ risk of falls cantly affected by advancing age. More recent investigations have largely confirmed these results. the total body weight of young people but this reduces Vandervoort & McComas164 reported that the to approximately 25% of total body weight in older strength of ankle plantarflexor and dorsiflexor muscles people.154 This reduction in muscle mass is strongly declined with advancing age but the differences were correlated with the reduction in total muscle cross- most marked from late middle age onwards. Van- sectional area, which has been shown to decrease by Schaik et al165 reported that ankle dorsiflexion strength approximately 40% between the ages of 20 and 60 was significantly decreased in subjects aged 60–80 years155 and involves reductions in both the size and years compared to subjects aged 20–40 years. Simi- number of muscle fibres.156,157 Although preliminary larly, Winegard et al166 compared ankle plantarflexor research suggested that age-related loss of muscle strength in subjects aged 20–91 years and found that fibres specifically affected type II fibres, more recent strength significantly decreased with advancing age. evidence indicates that although ageing results in a Although considerable differences in study popula- reduction in the size of type II fibres,158,159 the relative tions and methods used make direct comparisons of proportion of type I and type II fibres is largely unaf- these investigations difficult, it can be concluded that fected by age.153 However, ageing also results in older people exhibit between 30% and 60% of the motor unit remodelling, a process in which type II ankle strength of younger people.152 fibres are denervated and then reinnervated by col- lateral branches of type I fibres, resulting in the forma- FOOT MUSCLES tion of large, slow-twitch motor units.153 A summary of these changes is provided in Table 2.5. Although it has long been suspected that ageing is associated with atrophy of intrinsic foot muscles, evi- Age-related changes in muscle composition result dence to support such an assertion is scarce. Recent in significant reductions in muscle strength through- studies using magnetic resonance imaging in people out the body. Comparisons in muscle strength with and without diabetes indicates significant reduc- between young and older people (most commonly tions in the volume of ankle plantarflexors167 and the quadriceps muscles) generally report differences intrinsic foot muscles168–170 associated with the disease. in strength in the order of 20–40% between the age Given that many of the neuromuscular changes that of 30 and 80 years; however, people aged in their occur in diabetes are similar to those of advancing 90s may exhibit even larger reductions (50% or age, it is likely that comparisons between healthy greater).152,160 Because young men generally exhibit young and older people would reveal similar, but not greater strength than young women, their absolute as marked, differences in foot muscle volume. reduction in strength associated with age is greater, although the relative loss is similar for both Only two studies have investigated age-related sexes. Because of the difficulties associated with con- changes in the strength of foot muscles. Endo et al171 ducting long-term prospective studies, the rate at measured the force applied by the toes in 20 young which these changes occur is not fully understood; and 20 older participants when instructed to place all however, figures of 1–3% per year have been their bodyweight on their forefoot while leaning for- suggested.161,162 wards as far as possible. The results revealed that older participants generated 29% less force than younger

22 PHYSIOLOGICAL CHANGES IN THE AGEING FOOT participants. However, the contribution of ankle plan- with balance,98 walking speed105,173 and the ability to tarflexor strength using this testing procedure cannot rise from a chair174 and, subsequently, loss of strength be discounted and it is likely that the amount of force is a major contributor to falls175 and overall functional applied by the toes was also influenced by balance decline.176 However, there is solid evidence that age- ability. Furthermore, this approach is incapable of related loss of strength and its functional consequences delineating between the strength of the hallux and can be partly prevented, and possibly partly reversed, the lesser toes. To address these issues, Menz et al172 by resistance training.153 Secondly, although several used a pressure platform to measure toe plantarflexor authors have suggested that atrophy and/or imbal- strength in 40 young and 40 older participants while ance of foot muscles may be related to the develop- seated. The results indicated that older participants ment of hallux valgus177,178 and lesser toe deformities,169 exhibited 32% less plantarflexion strength of the the role of muscle weakness in the development of hallux and 27% less plantarflexion strength of the foot deformity remains unclear. lesser toes compared to younger participants, and women exhibited 42% less hallux plantarflexor SUMMARY strength than men. However, sex did not influence lesser toe plantarflexor strength. Normal ageing has a significant effect on the structure and function of the foot and these changes have con- FUNCTIONAL IMPLICATIONS siderable implications for the development of foot problems. A sound knowledge of these changes is The key functional implication of an ageing muscular essential for clinicians involved in the assessment and system is its effect on functional mobility in older management of foot disorders in older people. people. Lower limb strength is strongly associated References 9. Kurban RS, Bhawan J. Histologic changes in skin associated with aging. Journal of Dermatologic 1. Tarara EL, Spittel JA. Clues to systemic diseases Surgery and Oncology 1990; 16: 908–914. from examination of the foot in geriatric patients. Journal of the American Podiatry Association 1978; 10. Whitton JT, Everall JD. The thickness of the epi- 68: 424–430. dermis. British Journal of Dermatology 1973; 89: 467–476. 2. Muehleman C, Rahimi F. Aging integumentary system. Podiatric review. Journal of the American 11. Gosain A, DiPietro LA. Aging and wound healing. Podiatric Medical Association 1990; 80: 577–582. World Journal of Surgery 2004; 28: 321–326. 3. Thoolen M, Ryan TJ, Bristow I. A study of the skin 12. Thomas SE, Dykes PJ, Marks R. Plantar hyperkera- of the sole of the foot using high-frequency ultra- tosis: a study of callosities and normal plantar skin. sonography and histology. The Foot 2000; 10: Journal of Investigative Dermatology 1985; 85: 14–17. 394–397. 4. Bojsen-Moller F, Jorgensen U. The plantar soft 13. Smith L. Histopathologic characteristics and ultra- tissue: functional anatomy and clinical implications. structure of aging skin. Cutis 1989; 43: 414–424. In: Jahss MH, ed. Disorders of the foot and ankle: medical and surgical management. Philadelphia: 14. Ferrer T, Ramos MJ, Perez-Sales P et al. Sympa- Saunders; 1991: 532–540. thetic sudomotor function and aging. Muscle and Nerve 1995; 18: 395–401. 5. Hoffmann P. Conclusions drawn from a compara- tive study of the feet of barefooted and shoe-wearing 15. Sauder DN. Effect of age on epidermal immune peoples. American Journal of Orthopedic Surgery function. Dermatologic Clinics 1986; 4: 447–454. 1905; 3: 105–136. 16. Sunderkotter C, Kalden H, Luger TA. Aging and 6. Fenske NA, Lober CW. Structural and functional the skin immune system. Archives of Dermatology changes of normal aging skin. Journal of the Ameri- 1997; 133: 1256–1262. can Academy of Dermatology 1986; 15: 571–585. 17. Shuster S, Block MM, McVitie E. The influence of 7. Balin AK, Pratt LA. Physiological consequences of age and sex on skin thickness, skin collagen and human skin aging. Cutis 1989; 43: 431–436. density. British Journal of Dermatology 1975; 93: 639–643. 8. Gilchrest BA. Age associated changes in the skin. Journal of the American Geriatrics Society 1982; 30: 18. Lavker RM, Zheng P, Doug G. Aged skin: a study 139–142. by light transmission electron and scanning electron

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Assessment CHAPTER 3 CHAPTER CONTENTS THE INITIAL ASSESSMENT INTERVIEW The initial assessment interview 29 The initial assessment interview is one the most Medical and social history 29 important components of lower limb assessment in Medication use 31 older people. A considerable amount of relevant Assessment of cognitive status 31 information can be gleaned from a thorough and The presenting complaint 32 targeted evaluation of medical and social history – information that in many cases will influence the Systems examination 34 management strategy and assist in determining the Dermatological assessment 34 likelihood of a successful outcome. Because of Vascular assessment 36 the high prevalence of visual, auditory and cognitive Neurological assessment 39 impairment in older people, it is essential that the Musculoskeletal assessment 41 initial assessment interview is conducted in a quiet, well lit and unhurried clinical environment. History Diagnostic imaging 47 48 taking in older people may also require the aggrega- Plain film radiography 47 tion of information from multiple sources, including Bone scanning 48 family members, friends and carers. This can be chal- Ultrasonography 48 lenging, particularly when the information gathered Computed tomography 48 is inconsistent. In some cases it may be necessary to Magnetic resonance imaging obtain relevant information from each of these sources in isolation in order to develop a more accurate Functional assessment 49 picture of the presenting complaint. This clearly Activities of daily living 49 requires striking a balance between patient confiden- Objective measures of mobility 49 tiality and family involvement.1 An outline of areas to Evaluation of gait disorders 49 be covered in the initial assessment is provided in Falls risk assessment 51 Table 3.1. Assessment of the ability to perform basic foot MEDICAL AND SOCIAL HISTORY care 52 Previous and current medical conditions should be Footwear assessment 53 documented. In addition to current and previous Footwear and falls 55 medical conditions (including previous surgery), doc- umenting a family history may provide useful insights Assessing outcomes of treatment 55 into undiagnosed conditions with a strong hereditary Summary 56 References 56

30 ASSESSMENT Table 3.1 Components of the initial assessment Component Areas to be covered Medical history Current overall health status and diagnosed medical conditions Current medications Social history Previous medical history (including previous surgery) Family history Presenting complaint Cognitive status Systems examination Diagnostic imaging Age Functional assessment Gender Ethnicity Footwear assessment Social habits Sporting/leisure activity Spouse/family/carer support Location, duration, severity, previous treatments Dermatological Vascular Neurological Musculoskeletal Radiography, bone scanning, ultrasonography, computed tomography, magnetic resonance imaging Activities of daily living Mobility Gait disorders Falls risk assessment Ability to self-care Shoe fit and suitability Wear patterns predisposition (such as diabetes mellitus and psoria- Grandparents Died 65 yr Died 80 yr sis). To assist in recall, drawing a pedigree chart may type 2 diabetes be useful (Fig. 3.1), although in older patients it will Parents Died 68 yr be difficult to document family history accurately Died 72 yr beyond one previous generation. type 2 diabetes Documenting a thorough social history is essential Siblings Died 68 yr 77 81 84 type 2 diabetes to the management of foot problems in older people, as chronic foot conditions will often require ongoing Figure 3.1 Example of a pedigree chart for investigating self-management by the older person in their home hereditary predisposition to disease. Squares represent environment. Inspection of foot lesions, use of appro- males, circles represent females. Diagonal lines represent priate footwear and regular changing of wound dress- deceased family members, shaded circle represents the ings are all aspects of care that may be compromised patient. if the level of social support is inadequate. Thorough questioning of the older person’s household situation may also highlight limitations in the awareness of supportive care services (such as community nursing) that the older person may be eligible to access. Current

The initial assessment interview 31 and previous occupation and level of physical activity Secondly, the success of many clinical management may both be contributing factors to the develop- strategies is dependent on the ability of the older ment of foot problems and should be thoroughly person to undertake activities after they leave the evaluated. clinical environment. Failure to assess whether the older person is capable of undertaking these tasks may MEDICATION USE significantly reduce the likelihood of a good clinical outcome. Because of the age-related increased prevalence of chronic conditions, the use of prescription and over- Although the astute clinician may be able to detect the-counter medications increases dramatically with moderate to severe levels of cognitive impairment advancing age, with over 80% of people aged over 65 from general observations and history taking, a struc- years taking at least one medication and at least 20% tured approach using validated assessment tools will taking five or more.2 Although not all clinicians yield more valid findings. The most commonly used involved in the management of older people have the clinical screening tool for cognitive evaluation is the scope of practice to prescribe or withdraw medica- Mini-Mental State Examination (MMSE), a clinician- tions, all health-care professionals should thoroughly administered questionnaire consisting of 30 questions document medication use at the initial assessment, addressing several components of cognitive function.6 undertake regular reviews of medication use and be However, the MMSE is generally not feasible to wary of potential adverse reactions. It is often neces- implement into routine clinical practice because of its sary to request that older people bring their medica- length. In recognition of this, several shorter screen- tions to their clinical appointments to ensure accuracy ing tools have been developed that are highly corre- in documentation, and to ask specific questions lated with the MMSE. The simplest and most widely regarding over-the-counter medications such as used of these tests is the Clock Drawing Test (CDT).7 vitamin supplements, herbal medications, eye drops, Although several versions of this test exist, the most creams and ointments. The use of herbal medications basic approach requires requesting the patient to draw and supplements is highly prevalent among older a clock face with all the numbers and hands placed people; however, clinicians often do not document correctly, and to then state the time they have drawn. their use and older patients may not report them The following scoring system is then applied: (a) the during the medical history interview. A study of 1539 number 12 appears on top (3 points); (b) there are older people recently found that, while 34% used 12 numbers present (1 point); (c) there are two clearly some form of herbal medication, 70% had not distinguishable hands (1 point); and (d) the time is informed their physician.3 This is problematic, as all correctly stated (1 point). Scores of less than 4 are medications, irrespective of their prescription status, indicative of moderate to severe cognitive impair- have the potential to interact and contribute to adverse ment8 and warrant further diagnostic evaluation by a events. Common herbal medications that have been geriatrician. Examples of the CDT are shown in shown to have clinically important interactions with Figure 3.2. prescription medications include St John’s wort, gingko biloba, echinacea, saw palmetto, garlic and A BC ginseng.4,5 Figure 3.2 Examples of the clock-drawing test of ASSESSMENT OF COGNITIVE STATUS cognitive impairment. A. Normal (score 6). B. Moderate cognitive impairment (score 4). C. Severe cognitive Evaluating an older person’s cognitive status is an impairment (score 0). important aspect of lower limb assessment in older people for two major reasons. Firstly, obtaining informed consent to commence a clinical intervention requires that the older person is fully cognisant of the implications of the decision they are making. This is particularly important in relation to more invasive procedures such as foot surgery, where the advantages and disadvantages need to be carefully considered.

32 ASSESSMENT THE PRESENTING COMPLAINT Table 3.2 Key questions to ask about the presenting complaint – the example answers Location and history of the presenting are those that may suggest an ingrown toenail complaint Questions Example answers Having established a thorough medical and social history and evaluated the cognitive status of the older 1. Where is the problem? My big toenail person, the next step in the assessment process is to 2. How long have you had Two weeks specifically address the presenting complaint. The key questions that should be asked are listed in Table 3.2, the problem? I stubbed my toe in the along with some example answers. The location of the 3. How did it start? garden presenting complaint should first be accurately identi- fied. The use of visual aids, such as anatomical dia- 4. When does the problem When I’m walking grams or models, can be very useful in determining trouble you? the location of the problem, particularly if the older Taking my shoes off and person has difficulty describing the location or is 5. What makes the soaking my feet physically incapable of pointing to it (Fig. 3.3). Direct problem better? questioning regarding symptoms in other body Wearing my slippers regions may also provide useful diagnostic clues that 6. What makes the may not have been otherwise volunteered. problem worse? Wrapping my toe with cotton wool Pain assessment 7. What treatments have you already tried? Because pain is the most common reason for seeking medical care, it is important to assess the characteris- Right foot Left foot Figure 3.3 Anatomical map to assist in the documentation of pain location.

The initial assessment interview 33 tics and severity of pain in older people with foot American Orthopedic Foot and Ankle Society,13 the problems. Pain descriptors used by the patient, such Manchester Foot Pain and Disability Index14 and the as the nature of the pain sensation (e.g. burning, Bristol Foot Score.15 Although each of these scales aching, stinging, throbbing), the distribution of pain provides a quantitative measure of foot health status, (e.g. localised, radiating, superficial, deep) and pat- they vary considerably in relation to the constructs terns of pain (e.g. persistent, occasional, periodic) can measured, the level of psychometric validation under- greatly assist in reaching a diagnosis of the presenting taken and their responsiveness to change. The only complaint. Pain intensity can be evaluated using scale to be specifically validated in a large sample of several generic pain rating scales (such as the McGill older people is the Manchester Foot Pain and Dis- Pain Questionnaire9); however, these scales are gener- ability Index (MFPDI), which was originally devel- ally too time-consuming for routine administration in oped by Garrow et al.14 The MFPDI consists of 19 the clinical setting and may not always be relevant for statements prefaced by the phrase ‘Because of pain in foot disorders. Visual analogue scales, numerical my feet’, formalised under three constructs: func- rating scales and verbal descriptor scales are useful tional limitation (10 items), pain intensity (five items), indicators of pain intensity, are easily understood and and personal appearance (two items), with three pos- are simple and quick to administer; however, they do sible answers: ‘none of the time’ (score = 0), ‘some not provide any insights into the functional and psy- days’ (score = 2), and ‘most days/every day’ (score = chosocial impairments associated with pain. Further- 3). The remaining two items are concerned with dif- more, there is evidence that the visual analogue scale ficulties in performing work or leisure activities, which may not be appropriate for all older people, as many are omitted if the respondent is of retirement age have difficulty transforming the subjective nature of (Table 3.3). Menz et al16 recently administered the pain into a metric scale.10 MFPDI to 301 people aged over 75 years of age and found that the factor weightings in older people Several foot-specific pain and disability question- slightly differed from the initial validation study. In naires have recently been developed, including the the Menz et al16 study, the MFPDI was found to Foot Function Index,11 the Foot Health Status exhibit high internal consistency and represent four Questionnaire,12 a range of scales developed by the Table 3.3 The Manchester Foot Pain and Disability Index Question Original validation domains Domains in older people Because of pain in my feet . . . Functional limitation Activity restriction 1. I avoid walking outside at all Functional limitation Functional limitation 2. I avoid walking distances Functional limitation Functional limitation 3. I don’t walk in a normal way Functional limitation Functional limitation 4. I walk slowly Functional limitation Functional limitation 5. I have to stop and rest my feet Functional limitation Functional limitation 6. I avoid hard or rough surfaces where possible Functional limitation Functional limitation 7. I avoid standing for a long time Functional limitation Functional limitation 8. I catch the bus or use the car more often Functional limitation Activity restriction 9. I need help with housework/shopping Pain intensity Pain intensity 10. I still do everything but with more pain or Functional limitation Pain intensity discomfort Concern about appearance Concern about appearance Concern about appearance Concern about appearance 11. I get irritable when my feet hurt 12. I feel self-conscious about my feet Pain intensity Pain intensity 13. I get self-conscious about the shoes I have Pain intensity Pain intensity Pain intensity Pain intensity to wear Pain intensity Pain intensity 14. I have constant pain in my feet 15. My feet are worse in the morning 16. My feet are more painful in the evening 17. I get shooting pains in my feet

34 ASSESSMENT pain domains: functional limitation, pain intensity, A B concern about appearance and activity restriction Annular Flat (Table 3.3). These results indicate that MFPDI is an Nummular Pedunculate appropriate tool for assessing foot pain in older Linear Dome people. In addition, the MFPDI has been shown to Grouped Umbilicated be sensitive to improvement following a self-manage- Satellite Verruciform ment intervention,17 suggesting that it may also have some value as a measure of treatment efficacy. Assessing pain in older people who are incapable of verbal communication is a considerable challenge and requires observation of physical responses (such as guarding, fidgeting or restricted movement of the painful body part) and facial expressions (such as frowning, grimacing or excessive blinking).18 Clini- cians should never assume that those who are inca- pable of reporting pain do not experience it, and all attempts should be made to ensure that physical examination procedures are as pain-free as possible. SYSTEMS EXAMINATION Arcuate Spire Systems examination of the lower limb in older people Figure 3.4 Documentation of dermatological lesions. should be essentially the same as that for younger A. Arrangement. B. Surface contour. people; however, there are some particular issues that require additional consideration. The most funda- 3.4). Careful palpation of the skin may also yield mental issue in relation to systems examination in the useful clinical information regarding the texture, older patient is the tendency for some clinicians to depth, consistency and contents of the lesion. undertake less thorough assessments, because of the incorrect assumption that many aspects of ageing Assessment of skin dryness in the clinical setting cannot be effectively managed. This is by no means can be standardised using the xerosis scale developed limited to foot-care specialists – indeed, ageist assump- by Rogers et al.19 This scale consists of six images of tions have been demonstrated in most fields of medi- feet with varying degrees of skin dryness, ranging cine and often result in less detailed diagnostic from a mild, dusty appearance with some small skin approaches and the provision of less aggressive treat- flakes to large scaly plates and deep fissuring (Fig. ment approaches. Systems examination of the lower 3.5). Although the scale has not yet been validated limb in older people is likely to have a high diagnostic against gold standard measurements of skin hydration yield, and older people may be more likely to benefit (such as electrical capacitance),20 it has been shown from thorough assessments than younger, relatively to be a sensitive measurement of skin hydration in healthy patients. response to emollient application.21 DERMATOLOGICAL ASSESSMENT In addition to clinical observations, investigations such as mycology, bacterial and viral culture, and Thorough visual observation is the most fundamental histological assessment may be necessary. Mycology component of dermatological assessment of the lower is particularly important in relation to confirmation of limb in older people, as many skin lesions have char- suspected onychomycosis in older people for two acteristic patterns of presentation. Skin lesions should main reasons. Firstly, dystrophic nails may test posi- be carefully examined in relation to their arrange- tive for a wide range of organisms, necessitating the ment, shape, size, surface contour and colour (Fig. use of broad-spectrum antibiotics or antifungals. Sec- 3.4), and the lesion type should be documented using ondly, in approximately 20% of cases of suspected widely accepted dermatological nomenclature (Table onychomycosis, no fungal organisms can be identi- fied, suggesting that, as a result of misdiagnosis, some older people may undergo unnecessary antifungal

Systems examination 35 Table 3.4 Terminology of skin lesions Term Description Macule Localised area of colour change without Papule elevation Nodule Vesicle Solid elevation of skin <5 mm in diameter Bulla Solid elevation of skin >5 mm in diameter Pustule Accumulation of clear fluid within or below Cyst epidermis <5 mm in diameter Weal Accumulation of clear fluid within or below Plaque epidermis >5 mm in diameter Scale Visible collection of free pus in a blister Ulcer Nodule consisting of an epithelium-lined cavity filled with fluid or semi-solid material Transitory, compressible papule of dermal oedema Plateau-like elevation of skin >2 mm in diameter Accumulation of thickened keratin in the form of detachable fragments Circumscribed area of skin loss extending into the dermis treatment.22 Bacterial and viral culture should be con- Figure 3.5 Xerosis scale. 1: Dusty appearance and sidered in the case of longstanding paronychia or occasional minute skin flakes; 2: generalised dusty suspected secondary bacterial infection of pustular appearance and many minute skin flakes; 3: defined lesions or open wounds. It is essential that foot-care scaling with flat borders; 4: defined scaling with raised specialists establish good communication with their borders and shallow fissures; 5: large scales plates and local pathology providers to ascertain their sampling fissures; 6: large scale plates and deep erythematous and transport requirements. fissures. (With permission from Jennings MB, Alfieri D, Ward K et al. Comparison of salicylic acid and urea versus In general, all foot lesions in older people should ammonium lactate for the treatment of foot xerosis. also be investigated for evidence of underlying tissue A randomized, double-blind, clinical study. Journal of breakdown and ulceration, and chronic lesions should the American Podiatric Medical Association 1998; 88: be carefully documented for potential malignant 332–336.21) changes. The ABCD mnemonic (A – asymmetry; B – border irregularity; C – change in colour and D – absence of infection) may inform the selection of increase in diameter) is a useful general rule for routine treatment; and secondly, assessing the severity of a assessment of suspect lesions. A particularly high wound can provide useful insights into the risk of index of suspicion should also be applied to non- further complications such as infection and amputa- healing subungual lesions, as this is a relatively tion. A summary of key features to document when common site for the development of malignant assessing wounds is provided in Table 3.5. melanomas.23 This is discussed in more detail in Chapter 5. Wound severity can be assessed using the Wagner classification, which includes five grades: grade 1 (loss If skin breakdown is noted during a dermatological of dermal tissue only), grade 2 (loss of tissue that assessment, more detailed wound assessments need to exposes tendon or bone), grade 3 (loss of tissue that be undertaken. Wound assessment, although not an exposes tendon or bone with osteomyelitis or abscess), exact science, is essential for two main reasons. Firstly, grade 4 (gangrene of digits or forefoot) and grade 5 assessing the characteristics of a wound (such as the (extensive gangrene of the foot).24 The more recent underlying aetiology, location, size and presence or

36 ASSESSMENT Table 3.5 Components of wound assessment Characteristic Assessment Clinical meaning Location Mark on anatomical map Can inform diagnosis Influences selection of treatment Size Direct measurement of surface area, depth Affects prognosis Wound bed and volume Affects healing time and prognosis Document presence of necrotic or granulation Useful outcome measure tissue, slough, level of exudate and odour Can inform diagnosis Wound edges and Document colour, thickness, temperature, Provides insights into degree of healing surrounding skin presence of oedema May indicate infection Influences selection of treatment Can inform diagnosis Provides insights into degree of healing May indicate infection Influences selection of treatment University of Texas classification includes three grades: Table 3.6 The Fontaine classification of grade 0 (pre- or postulcerative site that has healed), peripheral arterial disease grade 1 (superficial wound not involving tendon, capsule or bone), grade 2 (wound penetrating to Stage Symptoms tendon or capsule) and grade 3 (wound penetrating bone or joint). Within wound grade there are four 1 Asymptomatic stages: clean wounds (stage A), non-ischaemic infected 2 Intermittent claudication wounds (stage B), ischaemic noninfected wounds 3 Ischaemic rest pain (stage C) and ischaemic infected wounds (stage D). 4 Severe rest pain with ulceration or gangrene, While both scales are clinically useful, the University of Texas scale has been found to be more predictive or both of healing time.25 Management of wounds is discussed in Chapter 7. over26 but often goes unrecognised in a large number of patients until the onset of symptoms.27 Given that VASCULAR ASSESSMENT many older people with asymptomatic PAD have evi- dence of subclinical cardiovascular disease, lower limb As outlined in Chapter 2, ageing is associated with arterial supply has been described as one of the ‘vital significant changes in the structure and function of signs’ of an older person’s health status,28 and foot- peripheral blood vessels, resulting in reduced function care specialists are well placed to detect early signs of of both the peripheral arterial and venous systems. vascular disease in asymptomatic older people. These changes commonly manifest in the foot and ankle, increasing the risk of arterial insufficiency, The severity of PAD can be classified according to venous stasis and ulceration. A thorough vascular the presenting symptoms, using the widely used Fon- assessment is therefore an essential component of taine classification (Table 3.6).29 The classical early lower limb evaluation. presentation of ischaemically induced pain is intermit- tent claudication, a tight, cramping pain in the calf Assessment of the peripheral arterial system region (or, less commonly, in the thigh, buttocks or foot) that occurs when walking and is relieved by rest. Age is a major independent risk factor for the devel- Intermittent claudication is thought to result from opment of peripheral arterial disease (PAD). PAD the build-up of metabolites in response to reduced affects approximately 15% of people aged 70 years and oxygenation of the surrounding muscle. When the older person rests, the metabolites are gradually

Systems examination 37 Table 3.7 The Edinburgh Claudication Questionnaire Question Response Sensitivity (%) Specificity (%) Do you get pain or discomfort in your Yes (if patient answers No, 99.3 13.1 leg(s) when you walk? stop here) 99.3 80.3 No 98.8 13.1 Does this pain ever begin when you are – – standing still or sitting? Yes 90.6 63.9 – – Do you get pain if you walk uphill or in Yes or No, depending on a hurry? severity of claudication Pain gone in 10 min or less Do you get pain if you walk at an Calf,* thigh† or buttock† ordinary pace on level ground? What happens if you stand still? Where do you get this pain? A positive classification of claudication requires the indicated response for all questions. *definite claudication = pain in calf. †Atypical claudication = pain in thigh or buttock in the absence of calf pain. cleared and the oxygen requirement of the muscles is in blood flow following occlusion (the capillary refill reduced, leading to an alleviation of symptoms. An time test) or limb elevation (Buerger’s test), and accurate diagnosis of intermittent claudication can be assessment of abnormal sounds detected with a obtained using a series of six questions, referred to as stethoscope (bruits). Two recent reviews of physical the Edinburgh Claudication Questionnaire (Table examination procedures for PAD32,33 indicated that 3.7). This questionnaire has been found to have a many of these observations are highly specific (i.e. sensitivity of 99% and a specificity of 91% in 300 their absence precludes the diagnosis of PAD) but symptomatic patients aged 55 years and over.30 have low sensitivity (i.e. their presence does not nec- essarily indicate that PAD is present). The most useful In more advanced PAD, a similar cramping pain clinical observations in detecting PAD were found may develop in bed (referred to as nocturnal or night to be abnormal pedal pulses, femoral artery bruit, cramps) as the heat of the bedclothes increases the unilateral cool limb and abnormal limb colour oxygen demand of the legs. Hanging the affected (Table 3.8). limb over the side of the bed relieves the pain as a result of a reduction in limb temperature and gravity- Although clinical observations remain an impor- induced increase in blood flow. Finally, the most tant component of peripheral arterial assessment, severe form of ischaemic pain occurs in the absence far greater diagnostic accuracy can be achieved by of any physical activity (referred to as rest pain) and calculating the ankle–brachial index (ABI) using a indicates that the arterial supply of the limb cannot sphygmomanometer and stethoscope or Doppler even meet quiescent metabolic requirements. At this ultrasound.34 The basic principle of the ABI is that stage, the limb is so severely ischaemic that ulceration systolic blood pressure in the lower limb should be and/or gangrene may develop – a state commonly equal to or slightly greater than that in the upper referred to as critical limb ischaemia, which infers limb. By dividing systolic blood pressure in the lower that, if limb perfusion cannot be improved, there is a limb by the pressure in the upper limb, an index can significant risk of limb failure and subsequent be calculated which provides a sensitive marker of amputation.31 peripheral blood supply.35 To perform the test, the patient is placed in a supine position with one arm In addition to the documentation of ischaemic flexed at the elbow and a blood pressure cuff is placed symptoms, clinical examination of suspected PAD around the upper arm and inflated until the brachial encompasses simple visual observations (such as loss pulse can no longer be heard with the stethoscope or of hair growth, atrophic or shiny skin and dystrophic Doppler. The cuff is then released slowly and the toenails), palpation (assessment of limb temperature point at which the pulse returns is documented from and palpation of pedal pulses), observation of changes

38 ASSESSMENT Table 3.8 Clinical observations indicative of peripheral arterial disease Test Test result indicative of peripheral arterial disease Sensitivity (%) Specificity (%) Abnormal pedal pulse Dorsalis pedis and posterior tibial artery pulses both 63 99 absent, or one present and one weak Femoral artery bruit Bruit present 29 95 Cool skin Unilateral cool skin 10 98 Abnormal limb colour Pale, red or blue limb 35 87 the manometer. The test is then repeated with the can be used, which involves placing the patient in a cuff placed above the ankle joint and the stethoscope supine position, elevating the leg until the pulse can or Doppler placed over the posterior tibial or dorsalis no longer be detected and measuring the vertical pedis artery. distance between the heart and the foot. A distance less than 40 cm is indicative of severe occlusion. There are several variations of the ABI technique in relation to the lower limb artery used (dorsalis More advanced techniques for the assessment of pedis, posterior tibial or both), how left and right lower limb ischaemia, such as exercise testing, Duplex readings are calculated (the highest, the lowest or the scanning, computed tomography and magnetic reso- average) and the number of tests performed.36 Simi- nance angiography are the domain of the specialist larly, several scoring systems have been devised, with vascular surgeon and are generally only indicated for normal values ranging from 0.9 to 1.5, and the PAD presurgical planning for bypass or limb salvage proce- cut-off value being reported as either less than 0.9 or dures.34 Referral for these investigations is indicated less than 1.0.36 In response to these variations, the where there is evidence of severe PAD, particularly if Standards Division of the Society of Interventional rest pain, ulceration or gangrene are present. Radiology recently developed a consensus statement for the use of the ABI.37 This statement recommends Assessment of the peripheral that the higher pressure of the dorsalis pedis or pos- venous system terior tibial artery for each foot be divided by the highest brachial artery pressure. The Division also Venous disorders are also common in older people39 recommended that the cut-off value for an abnormal and therefore clinical evaluation of venous insuffi- reading should be less than 1.0, with rest pain typi- ciency, including observations of telangiectasis, vari- cally occurring in patients with an ABI less than 0.5 cosities, oedema and venous ulcers, should also be a and critical ischaemia associated with an ABI of less routine component of geriatric lower limb assess- than 0.2.37 ment. Clinical observation is generally sufficient to arrive at a diagnosis of venous insufficiency; however, ABI values need to be interpreted with caution in the Perthes manoeuvre can provide further insight into patients with Mönckeberg’s sclerosis or diabetes, as the competency of leg veins. This test involves the the calcification of the arterial wall associated with application of a blood pressure cuff at mid thigh level these conditions may prevent adequate compression while the leg is dependent. The patient is then of the artery, thereby leading to falsely elevated index instructed to walk and rise up on to their toes to scores. Clinicians should suspect artery wall calcifica- stimulate the calf muscle pump. In a normal limb, the tion if the vessel cannot be compressed with pressures superficial veins will empty into the deep vein system above 200 mmHg or if the ABI calculated is well because of the action of the calf muscles; however, in above 1.0 in the presence of other visual signs of the presence of valvular incompetence, the superficial ischaemia. If this occurs, there are two alternative veins will remain distended and the limb may become approaches that can be used. Firstly, the peroneal erythematous. artery is rarely affected by calcification, so the ABI can be calculated using the peroneal artery pressure value It has also recently been demonstrated that the rather than the dorsalis pedis or posterior tibial arter- assessment of foot veins provides a useful insight into ies. Secondly, the pole test described by Smith et al38 the hydration status of an older person.40 Given that

Systems examination 39 dehydration is very common in older people (particu- Table 3.9 Clinical prediction rule for the larly those in institutional care), this simple assess- diagnosis of deep vein thrombosis (DVT) ment may help in the early detection of impaired fluid balance. To perform the assessment, the dorsal venous Clinical features arch vein is occluded by finger pressure and the vein Major points Active cancer is emptied by stroking proximally. The finger is then released, and the rate and degree of venous return is Paralysis, paresis or recent plaster observed, with a delay of more than 3 seconds being immobilisation of the lower limb indicative of potential dehydration. Recently bedridden >3 days and/or The most serious and potentially life-threatening major surgery within 4 weeks lower limb venous disorder, deep vein thrombosis (DVT), should always be suspected in older people Localised tenderness along the presenting with a hot, painful, swollen leg. However, distribution of the deep venous because anticoagulant therapy has potentially serious system side effects, it is important that DVT is also accurately ruled out when it is not present. To assist in this Thigh and calf swollen process, the clinical prediction rule of Wells et al41 is particularly useful (Table 3.9). This consists of 12 Calf swelling 3 cm asymptomatic side medical history items and clinical observations that (measured 10 cm below tibial can easily be undertaken as part of a routine consulta- tuberosity) tion. The classification of a patient as having a ‘high clinical probability’ of DVT on this scale has been Strong family history of DVT (≥2 first- shown to have 91% sensitivity and 100% specificity for degree relatives with history of DVT) the eventual imaging diagnosis of DVT. Minor points History of recent trauma (≥60 days) to Definitive diagnosis of DVT requires referral to a the symptomatic leg vascular laboratory for imaging techniques such as contrast venography, ultrasonography, computed Pitting oedema: symptomatic leg only tomography or magnetic resonance imaging.42 Con- trast venography, which involves X-raying the limb Dilated superficial veins (non-varicose) following the intravenous injection of a contrast in symptomatic leg only agent, is considered to be the gold standard diagnos- tic test for DVT. However, because of its invasiveness Hospitalisation within previous 6 and risk of thrombosis43 it has largely been replaced months by ultrasonography, which has an average sensitivity and specificity of 97% for detecting DVT in the thigh Erythema but a somewhat lower sensitivity for detecting calf DVT (approximately 75%).44 Clinical probability NEUROLOGICAL ASSESSMENT High ≥3 major points and no alternative Lower limb neurological assessment in older people diagnosis can be challenging, as it is often difficult to distinguish between observations of normal age-related changes ≥2 major points and ≥2 minor points and those related to a neuropathic process. The initial assessment interview and history taking may provide and no alternative diagnosis useful insights into conditions commonly associated with neuropathy, such as diabetes, chronic alcohol- Low 1 major point + ≥2 minor points and ism, vitamin B12 deficiency and the side effects of certain medications. However, self-reported ‘numb- has an alternative diagnosis ness of the feet’ cannot be relied upon as an indicator of sensory loss, as it has been shown to be a poor 1 major point + ≥1 minor point and no alternative diagnosis 0 major points + ≥3 minor points and has an alternative diagnosis 0 major points + ≥2 minor points and no alternative diagnosis Moderate All other combinations predictor of electrodiagnostically-confirmed neuro- pathy in older people.45 A wide range of clinical tests, such as tactile sensi- tivity testing with graded monofilaments, two-point discrimination, vibration sense (with tuning forks or neurothesiometers), temperature perception, pain detection, proprioception and lower limb reflexes are commonly used to detect lower limb sensory loss (Table 3.10). Although these tests are widely used,

40 ASSESSMENT Table 3.10 Clinical screening tests of lower limb sensory function Test Description Tactile sensitivity Cotton wool lightly stroked on the foot while patient has eyes closed. Patient is asked to report which foot is being stroked and the site Two-point discrimination Specially constructed devices with tips separated by varying distances are applied to the foot while patient has eyes closed. Patient is asked to report how many points can be felt (i.e. one or two) Pressure perception Flexible plastic filaments of varying thickness are applied to the foot while patient has eyes closed, and threshold detection level is documented. A commonly employed cut-off is the 10 g filament Vibration sense Three methods: 1. 128 Hz tuning fork 2. Graduated Rydel–Seiffer tuning fork 3. Neurothesiometer For each method, vibration sense is determined by applying the vibration to a bony prominence (apex of the hallux, first metatarsophalangeal joint or malleoli) while patient has eyes closed. Patient is asked to report any perceived sensation. The 128 Hz tuning fork produces a dichotomous test result (i.e. vibration sense is present or absent), the graduated tuning fork is semi-quantitative and the neurothesiometer produces a continuous score in volts, with values over 25 indicating neuropathy Temperature perception Two test-tubes filled with cold (<30°C) and hot water (>35°C) are applied to the foot while patient has eyes closed. Patient is asked to state which tube they find cooler/ warmer Pain Disposable sharp and blunt rods (such as Neurotips) are randomly applied to the foot while patient has eyes closed. Patient is asked to report which is the sharper rod Proprioception Dominant hallux grasped on medial and lateral surfaces by thumb and forefinger. Small amplitude up and down movements randomly administered, with patient asked to report direction of movement Ankle reflex Achilles tendon is struck with a reflex hammer while the foot is lightly dorsiflexed; plantarflexion response is detected with the other hand few have been adequately examined for validity in peripheral polyneuropathy. The results indicated that older people. Furthermore, the use of ankle reflex all clinical tests differentiated between older people testing or tuning forks alone to detect neurological with and without electrodiagnostically confirmed problems is confounded by the fact that over one- neuropathy; however, the best prediction of neuro- third of people aged over 70 years do not appear to pathy was provided by using a combination of three have an ankle reflex46 and a similar proportion cannot tests: the Achilles reflex, vibration sense at the toe and detect vibratory stimuli at the ankle.47 Therefore, position sense at the toe. Having two or three abnor- commonly employed clinical tests applied in isolation mal signs demonstrated a sensitivity of 91% and may not provide the same level of diagnostic accuracy specificity of 93% for neuropathy (Table 3.11). when applied to older people. Interestingly, the diagnostic accuracy of this protocol was not greatly affected by whether or not the par- To address this issue, Richardson48 recently devel- ticipants had diabetes, indicating that it may have oped a clinical screening approach incorporating a broad application for the detection of neuropathy range of clinical tests in 100 older people and corre- resulting from a range of conditions. lated these findings with electrodiagnostic tests of

Systems examination 41 Table 3.11 Clinical screening approach for the detection of neuropathy in older people Test Description Cut-off score Achilles reflex Achilles tendon is struck with a reflex hammer while the foot is Absent plantarflexion response Vibration sense lightly dorsiflexed <8 s Position sense 128 Hz tuning fork applied just proximal to the nailbed of the <8/10 correct responses hallux, and time taken until patient reports that the vibration has disappeared is recorded in seconds Dominant hallux grasped on medial and lateral surfaces by thumb and forefinger. 10 small-amplitude up and down movements randomly administered, with patient asked to report direction of movement MUSCULOSKELETAL ASSESSMENT Figure 3.6 Manchester scale for grading hallux valgus severity. A. No hallux valgus. B. Mild. C. Moderate. Foot deformity D. Severe. (With permission from Garrow AP, Papageorgiou A, Silman AJ et al. The grading of hallux The prevalence of foot deformity increases markedly valgus. The Manchester Scale. Journal of the American with age, because of the combined effects of muscu- Podiatric Medical Association 2001; 91: 74–78.50) loskeletal changes and the detrimental effects of footwear.49 As discussed in Chapter 1, the most common foot deformities in older people – hallux valgus and lesser toe deformities – are often associated with the development of hyperkeratosis and forefoot pain and have a significant detrimental impact on balance and functional ability. Hallux valgus can be easily graded in the clinical environment using the Manchester scale,50 which consists of four stan- dardised photos covering the spectrum of the defor- mity (Fig. 3.6). A recent study by Menz & Munteanu51 showed that gradings using this scale were signifi- cantly associated with hallux abductus and intermeta- tarsal angles obtained from foot radiographs. Lesser toe deformities (hammer toes, claw toes, mallet toes and retracted toes) can be simply evaluated by assess- ing the position and range of motion of the metatar- sophalangeal, proximal and distal interphalangeal joints. Each of these conditions is described in detail in Chapter 8. The length of each of the metatarsals, often referred to as metatarsal formula, is a useful assessment to undertake in older people, as excessively long or short metatarsals have been associated with the develop- ment of hallux valgus, hallux limitus and plantar keratotic lesions. In the normal foot, the second metatarsal is usually the longest and the fifth is the shortest, resulting in a metatarsal formula of 2 > 1 > 3 > 4 > 5, 2 > 3 = 1 > 4 > 5 or 2 > 3 > 1 > 4 > 5. Palpation and marking of the plantar metatarsal

42 ASSESSMENT heads while the corresponding toe is maximally A dorsiflexed has been shown to be a valid indicator of metatarsal formula determined from dorsoplantar LB foot X-rays.52 C The prevalence and clinical significance of the fore- foot and rearfoot malalignments described by Root et Figure 3.7 Calculation of the arch index. The length of al53 (including forefoot varus, valgus and supinatus, the footprint excluding the toes (L) is divided into equal plantarflexed and dorsiflexed first ray, and rearfoot thirds. The arch index (AI) is then calculated as the area varus and valgus) have been comprehensively debated of the middle third of the footprint divided by the entire in recent years. Some doubt has been raised in relation footprint area (AI = B/(A + B + C)). to whether these conditions actually exist, whether they can be accurately measured and whether they of the arch index can be time-consuming, a simple have a predictable impact on dynamic foot function.54 classification of high, normal and flat based on a visual In the absence of compelling evidence that these observation of the print may be more feasible for observations influence foot function or predisposition routine clinical use. Representative footprints obtained to foot problems in older people, it is my view that a from a sample of 292 people aged between 65 and standard geriatric foot and ankle assessment should 96, along with their arch index ranges, are shown in instead focus on obvious deformities that can be Figure 3.8. clearly recognised and documented. The Foot Posture Index (FPI) is also worthy of Foot posture consideration as a foot screening tool.58 The FPI involves visual rating of six criteria: palpation of the Despite the proposed relationships between foot talar head, observation of supra/infra malleolar cur- posture and the development of overuse conditions vature, inversion/eversion of the calcaneus, medial affecting the lower limb, there is still considerable prominence of the talonavicular joint, congruence of disagreement regarding how best to assess and classify the medial arch and abduction/adduction of the fore- foot posture.55 A wide range of tests have been pro- foot on the rearfoot. Each of these criteria is scored posed, including structured visual observation,56–58 on a 5-point scale (range −2 to +2) and the summed various footprint parameters,59,60 measurement of score provides a single index of the degree of the frontal plane heel position61,62 and assessment of the pronated/supinated posture of the foot, with higher position of the navicular tuberosity.63 Very few of scores representing a more pronated (flatter) foot. these tests have undergone rigorous validation. To The FPI has moderate to good reliability and FPI address this issue, Menz & Munteanu64 recently com- scores have been found to correlate with the frontal pared three clinical tests of foot posture (the arch plane position of the ankle joint complex during the index, navicular height and the Foot Posture Index) midstance phase of gait.58 FPI scores have been shown with arch-related measurements obtained from lateral to be significantly higher in older people than younger foot X-rays in 95 older people. The results indicated people (a mean of 4.4 compared to 2.5), which may that all three tests were significantly correlated with indicate an age-related flattening of the medial longi- radiographic measurements, with the strongest asso- tudinal arch.49 ciations found for navicular height and the arch index. A subsequent study involving plantar pressure mea- surements indicated that the arch index is a significant predictor of forces under the midfoot during walking,65 suggesting that this technique may be a useful clinical assessment to perform in older patients. To determine the arch index, a static footprint is obtained using an ink or carbon-paper imprint system, and the area of the middle third of the footprint is divided by the total area of the footprint (ignoring the toes). This is shown in Figure 3.7. A higher arch index represents a flatter foot. Because the calculation

Systems examination 43 High arch Normal arch Low arch (AI = 0 – 0.23) (AI = 0.23 – 0.26) (AI = 0.26 – 0.36) Figure 3.8 Simple visual categorisation of the arch index. C AB Figure 3.9 Assessment of joint range of motion in the foot. A. First metatarsophalangeal joint. B. Ankle joint dorsiflexion. C. Ankle joint complex inversion/eversion. Range of motion tification is not possible, broad classification of foot joint motion as normal, hypermobile or restricted is Assessing the available motion in the foot is a standard probably sufficient for clinical decision making. In and necessary component of the lower limb assess- older people, two joints are of particular importance ment. Preferred techniques for assessing joint range – the first metatarsophalangeal joint and the ankle of motion in the foot are shown in Figure 3.9. Unfor- joint – as these joints provide the main sagittal plane tunately, the reliability of range of motion assessments pivots during propulsion, and both joints undergo in the foot is somewhat questionable (particularly significant reductions in motion with advancing age.49 between clinicians), as the absolute ranges of motion First metatarsophalangeal joint dorsiflexion (assessed are small and the contribution of skin movement error in a non-weightbearing position – Fig. 3.9A) is is considerable. Nevertheless, although precise quan-

44 ASSESSMENT significantly correlated with the loading of the first ray subtalar joint with one hand while moving the mid- during gait,65 and restricted motion in this joint is tarsal joint through its full range of inversion/ associated with impaired balance.66 In older people, eversion, dorsiflexion/adduction and plantarflexion/ the normal value for this test is approximately abduction. Notable restriction in joint range of 55° (compared to approximately 80° in younger motion will be particularly evident in older people people).49 with midfoot osteoarthritis. Although there are several methods of assessing the Strength testing range of motion of the ankle joint, the weightbearing lunge test provides a functionally relevant indicator of Manual muscle testing of the foot and ankle can available ankle dorsiflexion and has been shown to be provide useful insights into strength deficits in older reliable and related to balance and functional ability people.71 The basic principle of manual muscle testing in older people.66,67 To perform the test, the lateral is to adequately stabilise the body part proximal to malleolus and head of the fibula are located and the muscle being tested and to apply firm pressure marked with a pen. The patient is then asked to stand directly opposite the line of pull of the muscle. with their foot placed alongside a vertically aligned Descriptions of hand placement and force application clear acrylic plate inscribed with 2° protractor mark- are shown in Table 3.12 and Figure 3.10. The simple ings and instructed to take a comfortable step forward grading system initially proposed by Kendall & with the contralateral leg. In this position, the patient Kendall72 is then applied (Table 3.13). Although is requested to bend their knees to squat down as low there is some subjectivity involved in this grading as possible, without lifting the right heel from the system (and care needs to be taken when comparing ground and while keeping the trunk upright. The findings between clinicians), it has been demonstrated position of the fibular head is marked on the clear that foot and ankle muscle testing observations are acrylic plate, and the angle formed between the lateral related to the intensity of muscle activity during malleolus and the fibular head is measured (Fig. gait.71 3.9B). The normal range of motion when performing this test is approximately 30–50°, with smaller values Another useful clinical muscle test is the paper grip being associated with impaired balance and functional test, which was first developed to assess muscle paraly- ability and an increased risk of falls.66,68 In the absence sis in the feet of leprosy patients.73 To perform the of the acrylic plate apparatus, similar measurements test, the patient is seated with their hip, knee and can be obtained by placing a gravity angle finder ankle at 90° and is instructed to use their toe muscles on the tibia while the patient assumes the lunge to push down on a 280 gsm piece of cardboard while position. the clinician stabilises the ankle and forefoot and attempts to slide the cardboard away from the toes The complex triplanar movements that occur at the (Fig. 3.11). The test is performed three times for the ankle, subtalar and midtarsal joints are particularly hallux and lesser toes individually and is documented difficult to quantify and several studies have reported as a pass if the patient can hold the cardboard for all low levels of reliability for frontal plane measurements three trials, and a fail if they fail to grip the cardboard of subtalar joint range of motion.69 Recently, however, on at least one trial. Menz et al74 have recently shown Menadue et al70 reported high levels of test–retest that significant age-related changes exist in toe plan- reliability for inversion/eversion range of motion tarflexor strength, and that the paper grip test is an measurements conducted with the patient in a seated accurate predictor of strength measurements obtained position using a flexible goniometer (Fig. 3.9C). from a plantar pressure platform. Toe plantarflexor Because the ankle is placed in a comfortable plan- strength has also been shown to be correlated with tarflexed position and the distal arm of the goniome- the magnitude of pressure borne by the toes during ter is placed on the dorsum of the foot, measurements gait65 and weakness of the toes is associated with obtained from this technique represent triplanar impaired balance and falls in older people.66,68 motion of the ankle–subtalar complex rather than ankle inversion/eversion per se. Mean values obtained The precision of manual muscle testing can be from 30 young participants were reported to be 32° improved with the use of hand-held dynamometers. of inversion and 10° of eversion.70 Midtarsal joint These devices contain a strain gauge and consist of motion is virtually impossible to quantify; however, a handle and a flat surface, which is placed against useful insights may be obtained by stabilising the the area being tested. Using the same principles as

Systems examination 45 Table 3.12 Manual muscle testing procedures Motion Positioning of Stabilising Resistance Instruction to Muscles tested patient hand hand patient placement placement Ankle Seated, leg Distal posterior Dorsomedial Dorsiflex and invert Tibialis anterior dorsiflexion extended off tibia surface of the foot by table the foot bringing toe Gastrocnemius, Ankle Distal anterior towards shin soleus plantarflexion Seated, foot tibia Plantar surface and leg of the foot With knee extended Gastrocnemius, Ankle extended off None (gastrocnemius) soleus plantarflexion table None and flexed >45° Distal medial (soleus) point Tibialis posterior Inversion Standing on tibia Medial aspect foot against one leg of foot resistance Peroneus longus Eversion using hand Distal lateral and brevis on table for tibia Raise heel 20 2nd–5th MTP and balance times, or until MTP: Lumbricals IP toe flexion MTP: Metatarsal unable to PIP: Flexor Lying on side PIP: Proximal complete full 2nd–5th MTP and to be tested, motion digitorum IP toe foot slightly phalanx brevis extension plantarflexed DIP: Middle Raise medial border DIP: Flexor of foot toward digitorum Hallux flexion Lying on side phalanx ceiling longus not being Extensor Hallux extension tested, foot Metatarsals Lateral aspect Raise lateral border digitorum slightly of foot of foot toward longus and plantarflexed MTP: 1st ceiling brevis metatarsal MTP: Flexor Supine, foot MTP: Proximal Flex or curl toes hallucis brevis resting on 1st metatarsal phalanx IP: Flexor table hallucis PIP: Middle longus Supine, foot phalanx Extensor hallucis resting on brevis (PIP) table DIP: Distal and longus phalanx (DIP) Supine, foot resting on Distal phalanx Extend toes table MTP: Proximal Flex big toe Supine, foot phalanx resting on table Proximal and Extend big toe distal phalanx IP, interphalangeal joint; DIP, distal interphalangeal joint; MTP, metatarsophalangeal joint; PIP, proximal interphalangeal joint.