Guidelines for the Diagnosis, Investigation and Management of Osteoarthritis of the Hip and Knee

Osteoarthritis is a frequent medical problem. In general practice, musculoskeletal problems account for one in 10 of new consultations, 18% of them for osteoarthritis [1]. Many patients with osteoarthritis receive all the treatment they need from their general practitioner. Others require specialist rheumatological advice, and a few need joint replacement surgery. Guidelines for the care of this common problem as it affects the lower limbs will assist in the provision of the most appropriate care and help to identify areas where further research is necessary.Osteoarthritis is best considered as one potential cause of 'joint failure'. Osteoarthritis may be classified first by the joint sites involved, second by the severity of the individual radiological features and third by the presence or absence of clinical features. Clinically, the picture includes use-related pain, night pain, difficulty in initiating movement, and crepitus and 'bony' swelling, together with reduced range of movement in a joint.Radiologically, there is loss of inter-bone distance, subchondral sclerosis and cysts, and marginal osteophytes.Pathologically, there is initial defibrillation and softening which lead to local loss of cartilage, increased formation of subchondral bone, marginal osteophytes with altered bone contour, and a variable inflammatory synovitis[2].Epidemiology and natural historyStudies conducted in the UK by the Royal College of General Practitioners in 1981/2 showed an annual incidence of symptomatic osteoarthritis of 50/1,000 in Women and 29/1,000 in men over 75 years old [1].Prepared on behalf of the Joint Working Group by
These figures, based on consultation rates, may be an underestimate of the true incidence of symptomatic osteoarthritis. A recent North American populationbased incidence study of symptomatic osteoarthritis suggested incidence rates of 50/100,000 patient years for hip osteoarthritis presenting for medical consultation, and 200/100,000 patient years for knee disease [bib_ref] Idiopathic symptomatic osteoarthritis of the hip and knee; a population based incidence..., Wilson [/bib_ref]. Osteoarthritis is rare before the age ofyears, but thereafter its frequency increases with age. It occurs most often in the distal interphalangeal joints, then in the knees, and is less common in the hips.
Relatively little is known of the natural history of osteoarthritis. The disease progresses slowly and the pattern of progression at hip and knee differs [bib_ref] Analysis by age, sex, and distribution of symptomatic joint sites, Cushnaghan [/bib_ref]. Many people have radiological changes without symptoms, and symptoms of pain show considerable fluctuations with time. Although some patients improve after a symptomatic period due to osteoarthritis, most either remain static or have progressive disease. In many patients knee osteoarthritis remains static over 10 years [bib_ref] Radiological progression of osteoarthritis: an 11-year follow-up study of the knee, Spector [/bib_ref].
Clinical assessment Successful management centres on careful questioning and physical examination of the patient. Pain and physical disability are the principal clinical problems, and their causes and treatment usually require independent consideration. Periarticular pain syndromes are common in association with ostearthritis, though they must be differentiated from it and from intraarticular and bone causes of pain. Anxiety, depression, or fibromyalgia may be more relevant to an individual's pain and disability at a particular point in time than synovitis or mechanical dysfunction. Symptoms and functional impairment vary with time, reflecting the dynamic nature of osteoarthritis and the complexity of pain perception.
Many elderly people have radiological changes of osteoarthritis; it is important to determine whether it is the cause of joint symptoms. Generalised arthropathies such as rheumatoid arthritis, psoriatic arthritis, and crystal arthritis should be considered [fig_ref] Table 1: Differential diagnosis of osteoarthritis [/fig_ref].
The main clinical assessments include: the presence of joint pain and tenderness; the presence of bony and soft tissue articular swelling; the distribution of joint involvement; the duration of morning stiffness; the presence of inactivity stiffness; and the presence of associated periarticular problems such as bursitis or tendinitis. Clinical signs which are more common in osteoarthritic joints than in other forms of arthritis include bony swelling and joint crepitus. Functional assessments are important, but are not often used in routine clinical practice. Standardised assessments such as the Health Assessment Questionnaire (HAQ) [bib_ref] Measurement of patient outcome in arthritis, Fries [/bib_ref] or the Arthritis Impact Measurement Scale (AIMS) [bib_ref] AIMS: an Anglicised version to assess the outcome of British patients with..., Hill [/bib_ref] can be used in osteoarthritis.
'Designer' instruments for osteoarthritis include the hip and knee scales of Lequesne, and associated measures [bib_ref] Indices of severity in osteoarthritis for weight-bearing joints, Lequesne [/bib_ref].
Investigation X-ray confirmation of the diagnosis of osteoarthritis is not always needed, especially in a general practice setting. X-rays should be taken if there is doubt about the diagnosis, if some other arthropathy is possible, or if joint replacement surgery is being considered. There is little advantage in using radiographs to determine the progress of osteoarthritis in routine clinical practice, but showing their radiographs to patients with osteoarthritis can help with patient education.
Other investigations, such as rheumatoid factor titres or assessments of the acute phase response by measuring the ESR, will usually be negative or normal in osteoarthritis, and are only indicated in cases where there is diagnostic uncertainty.

## Treatment
The goals of treatment are patient education, pain relief, and optimisation of function. A 'total patient' approach is appropriate. The treatment options are shown in .

## Patient education
It is essential that patients understand the nature and likely effects of osteoarthritis, because this can help in their therapy [bib_ref] Reduction of joint pain in patients with knee osteoarthritis who have received..., Rene [/bib_ref]. They should be told about the disease itself and be reassured that it differs from rheumatoid arthritis. They should also be informed that it often stabilises and that surgery is usually not needed. General advice should include: explaining the Crystal arthritis (gout and pyrophosphate crystal (deposition disease) Seronegative arthritis, eg psoriatic arthritis Periarticular syndromes, eg bursitis and tendinitis advantages of losing weight if obese (giving help, if needed); discussing footwear, stressing the importance of shock-absorbing insoles (found in 'trainers' and other shoes); and emphasising the importance of regular exercise, such as walking every day. Simple aids such as walking sticks should be encouraged.
Physcial and non-pharmacological treatments There are few prospective controlled evaluations of non-pharmacological therapies in osteoarthritis, though some, such as physiotherapy, are often used.
An exercise programme for patients with osteoarthritis of the knee and hip increases activity and improves walking time without worsening pain or exacerbating arthritis-related symptoms [bib_ref] Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis, Minor [/bib_ref]. Pain lessens and muscle power is maintained. Other types of physiotherapy are frequently undertaken in patients with osteoarthritis. The simplest method of treatment involves teaching patients to perform quadriceps exercises, supervising them, and providing motivation [bib_ref] The medical management of osteoarthritis of the knee: an inflammatory issue?, Mcalindon [/bib_ref] [bib_ref] Supervised fitness walking in patients with osteoarthritis of the knee. A randomised,..., Kovar [/bib_ref]. Other methods of physiotherapy include the application of heat and cold, ultrasound, short-wave diathermy, and hydrotherapy, but they have not been subject to adequate critical appraisal to judge their benefits. The evidence that physiotherapy is of significant advantage for patients is weak, but it may help when combined with other procedures, such as arthroscopic lavage [bib_ref] Arthroscopic lavage of osteoarthritic knees, Livesley [/bib_ref] ; further studies are needed in this area. Hydrotherapy can be of value in rehabilitating patients disabled with osteoarthritis. It is often used to treat painful hips and to increase the range of movement of joints.
It is conventional to recommend rest for an acutely painful osteoarthritic joint, though there is little evidence to support this contention; Bunning and Materson [bib_ref] A rational programme of exercise for patients with osteoarthritis, Bunning [/bib_ref] consider this advice to be an example of dogmatism in clinical practice. The case for repetitive exercise is more substantial. One study [bib_ref] Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis, Minor [/bib_ref] has shown a 44% improvement in patients after three months of aerobic pool exercises. The balance of evidence is in . Treatment options in osteoarthritis Analgesics Oral non-steroidal anti-inflammatory drugs Local non-steroidal anti-inflammatory drugs Local steroid injections Weight reduction Modification of mechanical factors (eg footwear, stick) Exercise Physiotherapy Arthroscopy, washout and debridement Replacement arthroplasty Osteotomy favour of exercise being beneficial in osteoarthritis, but further studies are needed to define the optimal approach [bib_ref] A rational programme of exercise for patients with osteoarthritis, Bunning [/bib_ref]. Quadriceps exercises are of considerable benefit in decreasing pain and increasing function in osteoarthritis of the knee [bib_ref] Physiotherapy in osteoarthritis of the knee, Chamberlain [/bib_ref] , and should be taught to patients.
Obesity is a well-established risk factor for osteoarthritis of the knee. It can predict the development of knee osteoarthritis 36 years later [bib_ref] Obesity and knee osteoarthritis: The Framingham Study, Felson [/bib_ref]. Weight change significantly affects the risk for the development of knee osteoarthritis; among obese women with a high risk of developing osteoarthritis, weight loss decreased the risk [bib_ref] Weight loss reduces the risk for symptomatic knee osteoarthritis in women. The..., Felson [/bib_ref]. At present there is no information as to whether or not weight loss is effective after symptomatic osteoarthritis has developed, though it is reasonable to expect that it has an effect.
Various aids and appliances are provided for patients. A stick may reduce the load on a painful joint and improve both confidence and mobility; insoles reduce the impact forces transmitted to painful joints and favourably influence joint mechanics [bib_ref] The mechanisms of treatment of osteoarthritis of the knee with a wedged..., Yasuda [/bib_ref] ; simple aids for use within the home or garden, such as a bath stool, may substantially overcome handicap.

## Pharmacological treatments
Drug therapy is an adjunct rather than a substitute for other treatments. Potential drug treatment includes analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), and local steroid injections; the concept of 'chondroprotection' by drugs remains controverisal and is currently unproven [bib_ref] Chondroprotection: myth or reality?, Brooks [/bib_ref].
Analgesics remain the first choice in drug therapy. The initial choice should be paracetamol, 0.5-lg given four to six hourly, up to a maximum of 4g/day. Nefopam hydrochloride, codeine phosphate, or combined preparations such as co-proxamol are often used, though evidence that they are better than paracetamol in osteoarthritis is scanty [bib_ref] Comparative effectiveness of five analgesics in patients with rheumatoid arthritis and osteoarthritis, Brooks [/bib_ref] , and any increase in efficacy may be offset by greater toxicity [bib_ref] Codeine plus paracetamol versus paracetamol in longer-term treatment of chronic pain due..., Kjaersgaard-Anderson [/bib_ref]. However, patients often prefer a combined analgesic. Stronger opioids should not be used; uncontrolled pain requires re-evaluation or an alternative approach.
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used. Their superiority over simple analgesics is poorly documented. For example, a recent study showed no benefit over paracetamol for low (analgesic) or high (anti-inflammatory) doses of ibuprofen [bib_ref] Comparison of an antiinflammatory dose of ibuprofen, an analgesic dose of ibuprofen,..., Bradley [/bib_ref]. Although inflammation may be a feature of osteoarthritis, there is little evidence that NSAIDs are acting other than as analgesics. Nevertheless, for individual patients NSAIDs may offer better symptom control than pure analgesics.
NSAIDs are associated with significant morbidity and mortality. Mortality from gastrointestinal complications (bleeding or ulceration of stomach, small bowel, and large bowel), cardiovascular sideeffects such as fluid retention, renal side-effects such as interstitial nephritis, and drug interactions, are particularly common and serious in elderly women, precisely the population with the highest requirement for control of osteoarthritic symptoms. NSAIDs should therefore only be considered when adequate doses of paracetamol have proved ineffective. When NSAIDs are used, it is advisable to prescribe the smallest effective dose, avoid repeat prescribing, and regularly reassess the need for NSAID therapy. This should be based on clinical assessment, vigilance for adverse reactions, and experience.
Monitoring for adverse effects, particularly in elderly women, has been advocated [bib_ref] Renal complications of NSAIDs: identification and monitoring of those at risk, Blackshear [/bib_ref] , though the value of such monitoring has not yet been assessed. Similarly, prophylaxis of stomach (and possibly small bowel) complications by 'gastroprotective' agents such as misoprostol is being increasingly discussed [bib_ref] Prophylaxis of non-steroidal anti-inflammatory drug gastropathy; a clinical opinion, Roth [/bib_ref]. Such therapy does reduce endoscopic abnormalities but evidence that it reduces the rates of serious complications such as bleeding or perforation is still awaited [bib_ref] NSAID-associated gastropathy?a role for misoprostol?, Hopkinson [/bib_ref].
Patients vary greatly in their response to NSAIDs, and there are no convincing data to favour some NSAIDs more than others for use in osteoarthritis.

## Major differences in the safety profiles of different
NSAIDs have yet to be established.
Transcutaneous administration of NSAIDs may produce symptomatic relief equivalent to oral preparations [bib_ref] Topical non-steroidal anti-inflammatory drugs, Doogan [/bib_ref]. Their use is limited to superficial joints such as the knee. There is no evidence for their effectiveness in hip osteoarthritis. It is still unclear whether they are more effective than rubefacients, though there are few clinical trial data on this issue.
Although certain NSAIDs show possible beneficial or detrimental effects on cartilage in experimental studies [bib_ref] Clinical aspects of chondroprotecdon, Huskisson [/bib_ref] , evidence that NSAIDs affect the osteoarthritic process in man is still being sought.
However, there is some evidence that indomethacin may have deleterious effects on hip damage [bib_ref] Effect of non-steroidal anti-inflammatory drugs on the course of osteoarthritis, Rashad [/bib_ref]. This may be due to a number of mechanisms including damage to cartilage or bone. Until the results of further research are available indomethacin is best avoided in elderly osteoarthritic patients, especially as it is more often associated with other adverse effects, such as central nervous system toxicity and fluid retention, than are other NSAIDs.
The use of corticosteroids remains controversial.
Intraarticular steroids often produce symptomatic relief, but this is transient and there is a significant 'placebo' response [bib_ref] The effect of intra-articular steroids in osteoarthritis: a double blind study, Friedman [/bib_ref]. Different joints may show varying responses. Aspiration of synovial fluid with local steroid injection gives symptomatic benefits, and is mainly advantageous in allowing other therapies to be successfully instituted [bib_ref] Are intra-articular steroid injections useful for the treatment of the osteoarthri tic..., Dieppe [/bib_ref] [bib_ref] A French controlled multicentre study of intra-articular corticosteroids in the treatment of..., Mazieres [/bib_ref]. In spite of fears to the contrary, repeated injections do not appear to be harmful [bib_ref] Intra-articular steroid therapy: repeated use in patients with chronic arthritis, Keagy [/bib_ref]. Other injectable compounds (eg glycosaminoglycan polysulphate, hyaluronate, and orgotein?a superoxide dismutase which inhibits free radical peristence) are still being assessed and are currently unlicensed in the UK.
When to refer patients for specialist advice Patients with osteoarthritis present to their general practitioner because of increasing pain, increasing disability, concern about the diagnosis, and the limitation of their activities. General practitioners should make the diagnosis, explain, educate, and advise, and initiate therapy. Referral for specialist advice may be necessary when there is a diagnostic uncertainty or there are persistent and poorly controlled symptoms. Increasing disability or a local complication such as locking of the knee are also reasons for referral. Most patients should be followed up in the community by their general practitioner. Patients need medical review of their osteoarthritis for advice on medication and physiotherapy; to look for complications such as bone collapse, avascular necrosis, instability of the joints, and acute crystal synovitis; and to minimise the risk of side-effects of medication by ensuring their early detection.
When to consider surgery Pain is the most important single reason for surgery. When pain becomes intolerable or unmanageable by medical means, operative treatment should be considered. Progressive loss of movement leading to deformity is a strong relative indication for surgery. When deformity exacerbates pain, for example in the varus osteoarthritic knee, correction of the deformity alone, in this example by osteotomy of the varus knee, may be indicated. The main reasons for surgery are given in [fig_ref] Table 4: Reasons for surgery [/fig_ref].
Osteotomy and arthroplasty are the mainstays of surgical treatment. The choice of procedures and implants is outside the scope of these medical guidelines [bib_ref] Hip and knee joint replacements. Drug and Therapeutics, Anonymous [/bib_ref]. Surgical intervention must be weighed against patients' social circumstances and age; it must also take account of potential loss of employment. The general effects of surgery on health status should also be weighed in the balance [bib_ref] How good are knee replacements?, Anonymous [/bib_ref] [bib_ref] Arthroscopic lavage of osteoarthritic knees, Livesley [/bib_ref]. Arthroscopic treatment with surface debridement, washout, and similar procedures is sometimes useful.

## Patients' needs and expectations
The first need is for adequate pain relief. The second need is for information and education. This will include explanations about why osteoarthritis has developed, its likely clinical course, the role of contributory factors such as obesity, and whether to rest or use the joints. Useful information in these areas is unfortunately limited.
When referral is needed for specialist rheumatological or surgical advice, this should be readily available. As well as specialist medical advice, a rheumatology unit may have nurses and paramedical staff with important roles in the management of patients with osteoarthritis. Direct access to physiotherapy and Increasing deformity Complications such as sudden locking of knee Progressive disability and dependency other paramedical services by general practitioners is common, but uncertainty remains as to whether these approaches are effective, or may be wasted effort.
The medical needs of people with osteoarthritis The needs of patients with osteoarthritis are large [fig_ref] Table 5: Facilities and services needed by patients with [/fig_ref]. A survey of self-reported disability in Great Britain by the Office of Population, Censuses and Surveys (OPCS) found that osteoarthritis involves 4% of adults up to 60 years of age, rising to 25% of 60-74 year-olds and 65% aged over 75 years [bib_ref] What do rheumatologists do? A pilot audit study, Bamji [/bib_ref]. Analysis of outpatient attendances in specialist rheumatology clinics in the UK showed that patients with osteoarthritis accounted for 10-45% of new referrals and 5-25% of follow-up patients [bib_ref] The present and future adequacy of rheumatology manpower; a study of healthcare..., Marder [/bib_ref] [bib_ref] Arthroscopic lavage of osteoarthritic knees, Livesley [/bib_ref]. In North America a surveyassumed a prevalence of 3,500 per 100,000 patient years and suggested that 60% of patients with osteoarthritis would require two specialist consultations. Applying these statistics to a UK district of 250,000 would mean 10,500 outpatient visits annually for osteoarthritis. This is a very heavy workload and would require either a substantial increase in the number of rheumatologists or a different approach to the management of the condition. The continued emphasis on the management of osteoarthritis within the primary care setting in the UK, and the contribution towards its management made by general practitioners, may explain the apparent divergence from North American practice.
Total hip arthroplasty for osteoarthritis is the most frequent major elective surgical procedure. Over 12 months in 1988/9 about 42,000 hips were replaced in NHS hospitals , 38% of them for osteoarthritis. In that year 36/100,000 were on the waiting list. The number of knee arthroplasties has increased to 15/100,000, 61% of them for osteoarthritis. In some Was a plain joint radiograph taken appropriately? 3.
Did the patient receive adequate education and advice?

## 4.
Were non-pharmacological treatments considered?

## 5.
Were aids and appliances given when needed?

## 6.
Was analgesia used when required or access available for other modalities of pain relief? 7. Were non-steroidal anti-inflammatory drugs used judiciously?

## 8-
Was intra-articular steroid injection given when needed?

## 9.
Was surgical referral considered when needed? 10. Was a follow-up plan made with good communication with general practitioners based on the need for most patients to be reviewed within the community? Progressive damage of major joints 3.
Loss of social independence, increasing disability and loss of work (if relevant) [bib_ref] Analysis by age, sex, and distribution of symptomatic joint sites, Cushnaghan [/bib_ref].
Serious drug reactions areas of the UK, especially London, the private sector makes a substantial contribution towards the number of hip and knee arthroplasties undertaken.

# Conclusions
Osteoarthritis is common and causes considerable persisting pain and disability. It is a frequent cause of consultations in general practice and referral for specialist rheumatological advice. It often necessitates replacement of major joints such as the hip and knee. Despite its frequency, the natural history of osteoarthritis and its overall progression are not well defined; nor are the relative advantages of different types of physical treatment and the persistent use of non-steroidal antiinflammatory drugs fully evaluated. It is necessary to define the effects of current medical and surgical treatments and interventions on the course and outcome of osteoarthritis to establish an appropriate environment in which to provide optimal treatment and help for patients with osteoarthritis. Such endeavours will require fuller epidemiological studies with systematic measures of disease severity, as judged by pain experienced and functional capacity. Suggested measures for audit are given in [fig_ref] Table 6: Suggested audit measures for lower limb Availability of consultant rheumatologists in local... [/fig_ref].
[table] Table 1: Differential diagnosis of osteoarthritis [/table]
[table] Table 3: Reasons for specialist referral [/table]
[table] Table 4: Reasons for surgery [/table]
[table] Table 5: Facilities and services needed by patients with [/table]
[table] Table 6: Suggested audit measures for lower limb Availability of consultant rheumatologists in local hospitals 2.Collaboration between GPs and hospital specialists 3.Access to surgery and combined rheumatology and orthopaedic clinics Process 1.Were appropriate clinical assessments made to establish the diagnosis and exclude other causes of joint pain? [/table]