Osteoarthritis pain and its treatment.

Pain is the most important symptom of osteoarthritis (OA) and the reason why individuals seek medical treatment. The anatomic cause is unclear and is likely to vary between individuals. Recent work confirms the heterogeneity of pain in OA with differences in severity, location, precipitating and relieving factors, and response to intra-articular anesthetic. Nonpharmacologic treatment of OA is important and evidence is now accumulating for interventions such as aerobic exercise, quadriceps exercises, footwear modification, education, and social support. Analgesia remains the first choice drug therapy: compounds more potent than acetaminophen are now available and effective. New cyclooxygenase-2 (COX-2) inhibitors may have a role in subjects for whom simple analgesia is inadequate. Glucosamine is a simple, safe product that appears to have a weak pain-relieving effect, and intra-articular hyaluronate injections may also have a limited role. Recent community studies confirm the benefit of joint replacement in OA, though a number of questions remain about the timing, indications, and alternatives to surgery.