Guidelines for managing osteoarthritis

Summarized by Robert W. Griffith, MD
September 28, 2000 (Reviewed: January 15, 2003)

Introduction

Osteoarthritis (OA) is the most common form of arthritis in older persons. Although there is no known cure, treatment tailored for the individual sufferer can reduce pain, maintain or even improve joint mobility, and limit functional impairment. A subcommittee of the American College Of Rheumatology has recently updated its recommendations for the medical treatment of people with OA, including the place of newer drugs (e.g. the COX-2 inhibitors). In their considerations, the subcommittee gave pre-eminence to data from systematic reviews, meta-analyses, and published findings of randomized controlled clinical trials.

Non-pharmacological treatment

Patient education and, where possible, participation in self-management programs can produce beneficial effects on pain and limitation of activity, and can improve quality of life measures. Along these lines, personalized social support (e.g. via telephone contact) can be valuable.

Obesity should lead to a dietary program - loss of body fat has been shown to correlate with improvement of symptoms. Physical therapy (heat therapy, aerobic exercise, range-of-motion and resistance exercises) must be individualized. Devices such as canes, crutches, or walkers will help with ambulation. Footwear must be adjusted to provide optimal support (e.g. lateral-wedged insoles).

A common physical finding in knee OA is quadriceps weakness, thought to be due to disuse atrophy. However, recent findings suggest that weakness in this muscle group may be a causative factor, rather than a result of OA. Quad exercises are therefore likely to help prevent deterioration of the arthritis. Knee exercises can also improve the loss of proprioception often seen in OA. If there is symptomatic involvement of the patello-femoral compartment, medial taping of the patella has proved useful.

Other treatments

The subcommittee notes that all drug treatments should be considered as additions, not replacements, for the non-pharmacological steps outlined above.

Which is better to start with - a simple analgesic (e.g. acetaminophen) or a nonsteroidal anti-inflammatory drug (NSAID)? Acetaminophen is equally effective as an NSAID for mild pain, but NSAIDs are better for more severe pain. It's worth trying full doses of acetaminophen (up to 4 g daily), because of its relative cost, efficacy and toxicity. One of the safest analgesics, acetaminophen can rarely exhibit hepatotoxicity, and may interfere with warfarin dosage regimens.

If pain is moderate to severe, initial treatment may consist of joint aspiration with intra-articular steroid injection, or an oral NSAID in full dosage. Before prescribing an NSAID, the physician should consider possible relative contraindications.

In one study, 20-30% of all hospitalizations and deaths for peptic ulcer disease in the USA were attributed to NSAID therapy, so that care must be taken in prescribing them. Risk factors for upper GI bleeding in patients given NSAIDs include: age of 65 years or older, a history of peptic ulcer disease or of upper GI bleeding, concomitant use of oral glucocorticoids or anticoagulants, the presence of comorbid conditions, and, possibly, smoking and alcohol consumption. Recently, the use of cardioprotective doses of aspirin (81-325 mg daily) has been shown to increase the risk of upper GI bleeding in NSAID-treated patients.

NSAIDs are also associated with an increased risk of reversible renal failure. Risk factors for this toxic effect include: intrinsic renal disease (usually defined as a serum creatinine concentration of >=2.0 mg/dl), age 65 and above, hypertension and/or congestive heart failure, and concomitant use of diuretics and angiotensin-converting enzyme inhibitors.

Topical analgesics may have a place in treating people with mild-to-moderate pain, and do not respond to acetaminophen. Methylsalicylate or capsaicin cream can be applied several times a day.

Starting treatment in someone at increased risk of an upper GI adverse effect Oral therapy

Two cyclooxygenase-2 (COX-2) specific inhibitors have recently become available - celecoxib and rofecoxib. These are equally effective as NSAIDs, but have a lessened potential to cause upper GI ulcers on endoscopy, and a lessened incidence of GI side effects. Unlike NSAIDs, the COX-2 inhibitors have no significant effects on platelet aggregation or bleeding time. However, they can cause renal toxicity, and they are much more expensive.

An alternative to COX-2 inhibitors is represented by the use of non-selective NSAIDs together with a gastroprotective agent, such as misoprostol or a proton-pump inhibitor such as famotidine or omeprazole. If there is a risk of NSAID-induced inhibition of platelet aggregation, nonacetylated salicylates (e.g. choline magnesium trisalicylate, salsalate) can be given, but ototoxicity may limit dosage.

If both NSAIDs and COX-2 inhibitors are contraindicated, tramadol, a centrally acting analgesic, can be considered. Its efficacy is comparable with that of an NSAID, but, as an opioid 'relative', it can cause nausea, constipation, and drowsiness. Addiction, however, is not a recognized adverse effect.

In extreme instances, severe pain may necessitate the use of a more potent opioid. Combinations of acetaminophen with codeine or dextropropoxyphene can be very effective, but tolerance, dependence, respiratory depression and severe constipation are likely adverse effects.

Intra-articular therapy

Hyaluronic acid injections (hyaluronan) have been shown to be beneficial in knee OA, although their mechanism of action is unknown. Pain relief is comparable to that achieved with oral NSAIDs, and outlasts the actual synovial half-life time. Hyaluronan is not recommended for hip OA.

Similar pain relief is obtained with an intra-articular glucocorticoid injection (e.g. triamcinolone hexacetonide) - its onset is sooner than after hyaluronan injection, but it doesn't last as long. This therapy is indicated if there are signs of local inflammation, and can be preceded by aspiration of the joint fluid. Post-injection flares of pain and/or inflammation are usually mild and short-lived.

Other treatments

Oral glucosamine and chondroitin sulfate have been shown to be efficacious in knee OA. However, the subcommittee reasons that ". . . . because of methodological considerations, including lack of standardized case definitions and standardized outcome assessments, as well as insufficient information about study design in a number of these published reports", it is " . . . . premature to make specific recommendations about their use at this time".

Similar considerations apply to the use of devices such as pulsed electromagnetic fields and lasers, acupuncture, dietary supplements and above-physiological doses of antioxidant agents. The NIH is conducting well-designed placebo-controlled studies with glucosamine, chondroitin sulfate, and acupuncture, which should help clarify the role of these treatments in OA.

A procedure known as tidal irrigation has been advocated for at least 5 years, but to date no controlled studies have been completed, so that it is not possible to state with any certainty whether it offers benefits or not - the placebo response for such procedures is always high.

Potential disease-modifying agents - matrix metalloproteinase inhibitors and growth factors - have been under investigation for some years, without any benefits in humans shown to date. Autologous cartilage transplantation and mesenchymal stem cell injections are still investigational approaches.

Surgical treatment

If a patient has failed on medical treatment and has progressive reductions in activities of daily living (ADLs), referral to an orthopedic surgeon is advisable. Arthroscopic debridement and/or osteotomy can be tried, but total joint arthroplasty will provide marked pain relief and functional improvement in the majority of cases. The recognized indications for total hip replacement and for total knee replacement have been published.¹, ² Rehabilitation is often the key to an optimal outcome.

Comment

The subcommittee has done an excellent job in summarizing present views on the place of different approaches to the treatment of OA. It is important that therapy starts with the non-pharmacological management, and then proceeds to first simple, and then more complex, analgesic medications. In this way it should be possible for the physician to hold out promise of successful pain control and retention of movement for as long as possible in this progressive debilitating disease.

Vioxx (rofecoxib), a COX-2 anti-inflammatory drug, has recently been withdrawn from all world markets by Merck, its manufacturer. Merck found that there was an increased risk of heart attack or stroke for people taking a standard dose (25 mg per day) for 18 months or more. The risk of such problems was twice that of people taking a placebo. However, someone's risk of having a heart attack or stroke is relatively low; double the risk means the chance of such an event is still "small," according to the USA Food and Drug Administration (FDA). Celebrex (celecoxib) and Bextra (valdecoxib) are other prescribed COX-2 inhibitors. Studies have so far indicated that only Vioxx poses a risk of heart problems. The FDA will examine the other two drugs to see if there is any cause for concern. Robert Griffith, Editor.

Source

• Recommendations for the Medical Management of Osteoarthritis of the Hip and Knee: 2000 Update. RD. Altman, MC. Hochberg, RW. Moskowitz, TJ. Schnitzer, Arthritis & Rheumatism, 2000, vol. 43, pp. 1905--1915

Footnotes
1. Total hip replacement.  NIH, NIH Consensus Statement, 1994, vol. 12, pp. 1--31
2. Knee replacement surgery for osteoarthritis: effectiveness, practice variations, indications and possible determinants of utilization. P. Dieppe, HD. Basler, J. Chard,  et al., Rheumatology, 1999, vol. 38, pp. 73--83

Related Books
The Arthritis Helpbook: A Tested Self-Management Program for Coping with Arthritis and Fibromyalgia
Falls in Older Persons : Prevention and Management

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