Obesity is also a risk factor, especially with hip and knee involvement. In OA, the articular cartilage is roughened and wears away. Bone spurs may form and the sensorial membrane thickens. As a result, the joint space narrows. The clinical presentation in OA includes an insidious onset of symptoms, including use-related joint pain that is relieved by rest, and joint stiffness that occurs with rest but resolves with less than 15 minutes of activity.
Physical exam reveals smooth, cool joints and coarse credits.
Particularly when the knee is affected, joint effusion is common. Radio logic findings in OA include narrowing of the joint space and increased density of subchondral bone. Bony cysts and entophytes are often present. As OA is typically a no inflammatory disease, sedimentation rate and C-reactive protein, both markers of inflammation, are normal. Unlike rheumatoid arthritis and systemic lupus erythematosis, antinuclear antibodies are absent from the serum .