musculoskeletal and connective tissue disorders
Osteoarthritis (OA)
Key Points
Osteoarthritis, the most common joint disorder, becomes particularly common with age. Key pathophysiologic features include disruption and loss of joint cartilage and bony hypertrophy. Osteoarthritis can affect particular joints (sometimes secondary to injury or another joint problem) or be generalized (often as a primary disorder). Symptoms include gradual onset of joint pain that is worsened by weight-bearing or stress and relieved by rest, and stiffness that lessens with activity. Confirm the diagnosis with x-ray findings such as marginal osteophytes, narrowing of the joint space, increased density of the subchondral bone, bony remodeling, and sometimes subchondral cyst formation and joint effusion. Discrepancy between severity of symptoms and severity of changes on imaging is common. Treat primarily with physical measures that involve rehabilitation; support devices; exercise for strength, flexibility, and endurance; patient education; and modifications in activities of daily living. Treat adjunctively with drugs (eg, analgesics, nonsteroidal anti-inflammatory drugs, muscle relaxants) and surgery. 