Patellofemoral instability.

This review describes the normal patellofemoral joint and detail the mechanism and anatomic elements that predispose patients to patellar instability. The treatment options for both acute and chronic injuries are described and the rationale behind their approach to this problem is explained. In general, most acute dislocations should be treated nonoperatively unless the instability is associated with an osteochondral injury. Chronic dislocators should be treated based on an understanding of the patient's individual reason for recurrent instability. This is achieved with a thorough history, physical examination, and imaging studies. This information can help the clinician select the most appropriate proximal and or distal procedure.