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Printed in China The Publisher The publisher's policy is to use paper manufactured from sustainable forests RUNNING HEAD RECTO PAGES ix Foreword A chance remark at the end of a Rheumatology stayed at home rather than spoil the outfit with conference in 2004, when I asked the Rheumatology her everyday but clumsy shoes. clinicians present to pay more than lip service to There are over 8 million arthritis patients in the the problems that patients experience with their U.K., and the overall prevalence of females is far feet, has given me the opportunity to write the greater than men. Of course women are not the foreword to this book. only ones to experience pain and discomfort Small joint inflammation is the hallmark of early in their feet. Rheumatoid Arthritis is a time Rheumatoid Arthritis, yet attention to the problems consuming disease, everyday activities of work of the foot and ankle has been the Cinderella of and leisure take longer to perform, particularly the Rheumatoid world. As any clinician or health when your feet are swollen, painful and deformed. professional will tell you it is easier to look at the This often results in decreased capacity for paid hands in an examination rather than the feet and and unpaid work. The cost of the disease is consequently there appears to be a lack of attention immense with many working days lost per year. paid to this problem. The book points out that there is no such thing as Stylish shoes are an essential part of most a typical ‘rheumatoid’ foot. As a patient I am women’s wardrobe. In my cupboard there are still always amazed at the variety of disabilities that several pairs of fashionable shoes, remnants of the Rheumatoid Arthritis can exhibit. Diagnosing the days when I was still working. They were to me a needs of an individual patient is paramount: symbol of my position and authority when smart thereis a person connected to the foot! Many foot dressing was the vogue. I cannot wear them now, problems are under reported, and only 25% of but somewhere in the back of my mind there is a patients have access to NHS care, and there is an possibility that just one day I might be able to. A even greater discrepancy amongst patients with friend of mine, another patient with Rheumatoid Rheumatoid Arthritis. Foot health care service pro- Arthritis, was invited to a rather ‘posh’ wedding. vision needs to be responsive to the varying needs Much time was taken choosing an expensive of the patients throughout the course of their dis- outfit, and a pair of shoes that would not look too ease. As the disease progresses patients will need clumsy but would be comfortable. Several days more than someone to deal with corns and calluses. before the wedding she experienced a ‘flare’ in Acomprehensive foot care programme should lead her disease and on the morning of the ‘looked- to treatment for more demanding problems when forward-to-day’ was unable to wear the shoes needed, such as vasculitis, ulceration, neuropathy because her feet were so swollen. The result, she and necessary surgical intervention. Getting the x FOREWORD timing right is so important. My Rheumatoid clinic improve patient care in the future, even though has recently introduced the provision of a podia- they may be difficult to establish. As a patient trist to attend monthly clinics, an overdue luxury with increasing foot problems I am grateful that that is not available everywhere. such a book now exists for clinicians and health This book will draw attention to the varying professionals. needs of patients as their disease progresses, and to the need for multidisciplinary teams to Mrs Enid Quest RUNNING HEAD RECTO PAGES ix Foreword A chance remark at the end of a Rheumatology stayed at home rather than spoil the outfit with conference in 2004, when I asked the Rheumatology her everyday but clumsy shoes. clinicians present to pay more than lip service to There are over 8 million arthritis patients in the the problems that patients experience with their U.K., and the overall prevalence of females is far feet, has given me the opportunity to write the greater than men. Of course women are not the foreword to this book. only ones to experience pain and discomfort Small joint inflammation is the hallmark of early in their feet. Rheumatoid Arthritis is a time Rheumatoid Arthritis, yet attention to the problems consuming disease, everyday activities of work of the foot and ankle has been the Cinderella of and leisure take longer to perform, particularly the Rheumatoid world. As any clinician or health when your feet are swollen, painful and deformed. professional will tell you it is easier to look at the This often results in decreased capacity for paid hands in an examination rather than the feet and and unpaid work. The cost of the disease is consequently there appears to be a lack of attention immense with many working days lost per year. paid to this problem. The book points out that there is no such thing as Stylish shoes are an essential part of most a typical ‘rheumatoid’ foot. As a patient I am women’s wardrobe. In my cupboard there are still always amazed at the variety of disabilities that several pairs of fashionable shoes, remnants of the Rheumatoid Arthritis can exhibit. Diagnosing the days when I was still working. They were to me a needs of an individual patient is paramount: symbol of my position and authority when smart thereis a person connected to the foot! Many foot dressing was the vogue. I cannot wear them now, problems are under reported, and only 25% of but somewhere in the back of my mind there is a patients have access to NHS care, and there is an possibility that just one day I might be able to. A even greater discrepancy amongst patients with friend of mine, another patient with Rheumatoid Rheumatoid Arthritis. Foot health care service pro- Arthritis, was invited to a rather ‘posh’ wedding. vision needs to be responsive to the varying needs Much time was taken choosing an expensive of the patients throughout the course of their dis- outfit, and a pair of shoes that would not look too ease. As the disease progresses patients will need clumsy but would be comfortable. Several days more than someone to deal with corns and calluses. before the wedding she experienced a ‘flare’ in Acomprehensive foot care programme should lead her disease and on the morning of the ‘looked- to treatment for more demanding problems when forward-to-day’ was unable to wear the shoes needed, such as vasculitis, ulceration, neuropathy because her feet were so swollen. The result, she and necessary surgical intervention. Getting the x FOREWORD timing right is so important. My Rheumatoid clinic improve patient care in the future, even though has recently introduced the provision of a podia- they may be difficult to establish. As a patient trist to attend monthly clinics, an overdue luxury with increasing foot problems I am grateful that that is not available everywhere. such a book now exists for clinicians and health This book will draw attention to the varying professionals. needs of patients as their disease progresses, and to the need for multidisciplinary teams to Mrs Enid Quest RUNNING HEAD RECTO PAGES xi Acknowledgements The authors would like to pay tribute to the tech- We would also like to thank the many patients nical expertise and support of Mr Brian Whitham, whose images appear in this book and those who Research Technician at the University of Leeds. contributed to the case studies in Chapters 2 and 6. RUNNING HEAD RECTO PAGES xiii Contributors S J McKie N. J. Harris Consultant Musculoskeletal Radiologist, Consultant Orthopaedic Surgeon, Queen Margaret Hospital, Dunfermline Leeds FRSC (TR and Orth) P J O’Connor N. Carrington Consultant Musculoskeletal Radiologist, Consultant Orthopaedic Surgeon, Leeds General Infirmary, Leeds York FRCS (TR and Orth) 1 1 Chapter Current concepts in rheumatoid arthritis INTRODUCTION CHAPTER STRUCTURE Rheumatoid arthritis (RA) is the commonest inflam- Introduction 1 matory arthritis seen in the UK, Europe and North Epidemiology of rheumatoid arthritis 2 America. It causes inflammation and destruction of Risk factors for disease onset, persistence synovial joints and, in many cases, has an additional and severity 3 systemic component that is associated with increased Natural history 4 morbidity and mortality. The cost of the disease, both Pathogenesis of rheumatoid arthritis 6 in individual and societal terms, is considerable. RA The role of genetic factors 7 comprises the bulk of the work done by a general The international classification of functioning, rheumatologist and is the commonest reason for refer- disability and health (ICF) 7 ral from rheumatology to podiatry. The treatment of The epidemiology of foot disease in rheumatoid RAis rapidly changing and with new treatments has arthritis 9 come new hope of preventing the deformities seen Factors associated with the prevalence and after many years of disease. progression of foot disease in rheumatoid The foot remains a neglected area in rheumatology; arthritis 13 it is far easier to look at the hands than to look at the Summary 14 feet. Examining the feet requires a certain amount of discomfort both for the examiner (who usually has to bend over from sitting to peer at these appendages) and the patient who has to struggle with footwear and socks or ‘tights’. From our experience in post-graduate education we know that rheumatologists and podia- trists feel in need of more knowledge and skills with respect to the foot in RAand feel incapable of examin- ing that part. We hope this book will fulfil this educa- tional role. It is our intention to make this book as evidence- based as possible. Inevitably, there will be areas where the evidence base is weak; in these instances we will be clear when we write from personal experience and practice. One point is clear from the existing literature in this field; the specialty of orthopaedics has contributed significantly to what we know about the foot in RA. In this context, we would make a plea that use of the term ‘rheumatoid foot’ is abandoned. Why? Well, there is no such thing 2 THE FOOT AND ANKLE IN RHEUMATOID ARTHRITIS as a typical ‘rheumatoid foot’; RA is a complex ficity, but these indicators can be changed, as already disease that may manifest in several different ways. mentioned. The method of developing the criteria is The term ‘rheumatoid foot’ is somewhat derogatory also important. Usually, clinicians recruit people they and demeaning. It tends to ignore the fact that there regard as having typical disease, but, obviously, this is a person connected to the (painful) foot (a person may vary from clinician to clinician. More important with the disease of RA) the impact of which will are the cases used as ‘controls’ with whom the compar- depend on many factors, including the other mani- ison is made and from which the criteria are derived. festations of the disease, personal and contextual The criteria will perform best in populations of a simi- factors. The WHO’s International Classification of lar composition to those on which they were devel- Functioning, Disability and Health enables health oped. For example, if there were no cases of psoriatic professionals to describe these aspects in a composite arthritis in the control population at the time the crite- form, synthesizing different perspectives of health. ria were developed it would be misleading to use these These interactions and the protean manifestations of criteria to pick rheumatoid from psoriatic arthritis in a the disease should be addressed by anyone treating study using these criteria. Further, if the cases of RA people with RA. used to develop the criteria were all of well-established disease then these criteria would have limited useful- ness for early disease; in fact, this is exactly one of the EPIDEMIOLOGY OF RHEUMATOID limitations of the 1987 criteria as the average disease ARTHRITIS duration of the cases was 7.7 years. The incidence of RA is falling. There are several reasons for this, briefly summarized below: 1. Changing diagnostic criteria Table 1.1 The 1987 revised criteria for the classification 2. Changing methods of determining disease ofrheumatoid arthritis 3. Falling incidence of disease itself. At least four of the following features should be present for The diagnosis is usually made according to specific at least 6 weeks: criteria. In RA, the criteria commonly used are those 1. early morning stiffness of the joints for at least 60min defined by the American College of Rheumatology 2. soft-tissue joint swelling observed by a physician ofat (see Table 1.1) (Arnett et al. 1988). It is important to least three of the following areas: note that in the absence of a gold standard (such as a a. proximal inter-phalangeal joints single clinical sign, radiological feature or pathological b. metacarpophalangeal joints test) these criteria only reflect the clinical features used c. wrist joints by clinicians in the clinic. They are used in general for d. elbow joints classification purposes to allow comparison between e. knee joints different populations and to serve as entry criteria for f. ankle joints g. metatarsophalangeal joints clinical trials. They are not designed as criteria for 3. soft-tissue swelling observed in a hand joint in at least diagnosing the individual patient in the clinic or at the one of the following areas: bedside; these may be quite different. In this latter case a. proximal inter-phalangeal joints clinical judgement is important, not the number of cri- b. metacarpophalangeal joints teria the patient fulfils. Classification criteria do have c. wrist joints an important role, nevertheless, and are designed to be 4. symmetry of joint involvement of the following joint specific rather than sensitive; although, ideally, criteria pairs: should have both high sensitivity and specificity. In a. proximal inter-phalangeal joints reality, criteria are either very specific or very sensitive b. metacarpophalangeal joints and the level of each can be manipulated during their c. metatarsophalangeal joints d. wrist joints development to serve the purpose required. The 1997 e. elbow joints ACR criteria were reported to have a sensitivity of f. knee joints 91% and a specificity of 89%; this means that 9% cases g. ankle joints of RAwere not ‘picked up’ by the criteria and, con- 5. the presence of subcutaneous rheumatoid nodules versely, 11% of cases diagnosed as RA were, in fact, 6. the presence of rheumatoid factor in the serum some other arthropathy. 7. the presence of erosions on radiographs of wrists Just how well classification criteria perform will orhands. depend, as noted above, on the sensitivity and speci- Current concepts in rheumatoid arthritis 3 To overcome this problem it has been suggested Given the above considerations a number of studies that alternative criteria be developed for early dis- have attempted to estimate the incidence and preva- ease. In fact, an alternative classification tree method lence of RA. The prevalence of RAin the population is was developed for diagnosing RA using the same approximately 0.8%, a risk that is doubled for relatives patients as the criteria given in Table 1.1. The advan- of confirmed cases (Hawker 1997). The overall preva- tage of this method is that a diagnosis can be made lence is higher in women (1.2%) than men (0.4%). without features that often develop later in the dis- Approximately two-thirds of new cases arise in ease, such as bony erosions. Harrison et al. have females (Young et al. 2000) and the average age at shown that the tree method is more sensitive for diag- onset is 55 years, although there is evidence that the nosing early disease, but loses specificity; an average age of onset is rising in both women and men, inevitable trade off in this situation (Harrison et al. and that new-onset cases in the elderly are equally 1998). However, it may be futile to try and develop male (Symmons 2002). Overall prevalence rates are specific criteria for early RA if all early arthritis is falling, although this may, in part, be a fall in severity, undifferentiated. Berthelot has suggested that early as the criteria given above contain severity markers arthritis may progress to whichever definitive arthri- (such as rheumatoid factor, nodules and erosions). The tis (for example, RAor spondyloarthropathy) accord- prevalence of RAfalls with latitude in Europe with the ing to individual characteristics such as HLA status Italian prevalence about a half of that in Finland. and cytokine polymorphisms. In a study of 270 cases The incidence of RA, the number of new cases of early arthritis (less than 1 year duration), the occurring in a defined time period (usually a year), is French group obtained longitudinal data for 30 also falling. This fall is probably independent of the months, relating the initial diagnosis to that given at other factors outlined above (Uhlig & Kvien 2005). the final visit (Berthelot etal. 2002). Over one-third of It is, however, a difficult statistic to obtain and true diagnoses changed in the follow-up period. community incidence figures are uncommon. In the UK If a diagnostic biological marker were available diag- some of the best epidemiological data have come from nosis would be much more straightforward. Abiological the Norfolk Arthritis Register (NOAR), which ‘cap- marker usually has pathological relevance, such as the tures’ all cases of persistent early arthritis presenting finding of tubercle bacilli in the sputum of someone to general practitioners in a well-defined and stable with suspected pulmonary tuberculosis. For some time population (Symmons et al. 1994). The current esti- it was thought that rheumatoid factor fulfilled this role mate of incidence of RAis 25–50/100 000/year. In con- in RA. But it later became clear that rheumatoid factor is trast, in the USAbetween 1955 and 1964 the incidence present in only about 75% of cases of RA. Rheumatoid was 83/100 000/year (Doran etal. 2002). factor, however, may still have a pathological role (see section on aetiology) and certainly does have a role in predicting the course of the disease (see below). Further biological markers have been sought. Antibodies to keratin, in particular anti-cyclic citrulli- KEY POINTS nated peptide antibodies have been found to be more specific (95%) for RAthan rheumatoid factor. However, ● The overall prevalence of rheumatoid arthritis this occurs at the cost of lower sensitivity (56%) (Bas (RA) is 0.8% (1.2% in females, 0.4% in males) et al. 2003). This test may, however, be of more use in ● The incidence of RA in the UK is estimated to be situations where it is desired to have a very low rate of 0.025–0.05% false positives. Other ways of looking at RAare under ● The prevalence and incidence of RA are falling investigation. For example, magnetic resonance imaging (MRI) is a very sensitive technique for detecting inflam- mation. Joints not inflamed clinically may show exten- sive abnormalities. The same is true, but to a lesser RISK FACTORS FOR DISEASE ONSET, extent, for ultrasound (U/S), especially power Doppler PERSISTENCE AND SEVERITY U/S. Both these techniques are discussed in the chapter on imaging. The point to be made here is that using Whatever triggers the inflammation in early RAit is these new techniques may change the way we diagnose clear that a self-limiting inflammatory arthritis can and treat inflammatory diseases such as RA. MRI and occur, but may resolve spontaneously. It is those peo- U/S may permit much earlier diagnosis, but it is doubt- ple in whom resolution does not take place that go on ful if they will be incorporated into diagnostic criteria to develop established disease. The factors contribut- until their cost and availability become more favourable. ing to onset, persistence and severity are different, but
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