Most patients with articular knee pain have a relatively diffuse pain that is not well localized to one area of the knee. Tenderness is localized to the infrapatellar tendon, with no associated swelling, and conservative measures almost always result in resolution of symptoms. This condition is seen predominantly in adolescent males and is thought to represent a traumatic avulsion injury.
Symptoms usually resolve with temporary immobilization and slow resumption of activities.
An area of localized fluid collection is usually detectable, and aspiration is often needed for diagnosis. As in olecranon bursitis of the elbow, prepatellar bursitis may be associated with trauma, localized bacterial infection, and, less commonly, gout, rheumatoid arthritis, and atypical infections. The differentiation between trauma and infection is particularly important for initiation of appropriate therapy. Patients with this condition complain of pain at night or when climbing stairs, and an area of localized tenderness can be found on examination. Coexistent osteoarthritis of the knee joint is present in many patients, and relief with local heat or injection of glucocorticoids and anesthetic may be helpful both diagnostically and therapeutically.