Patellar instability.

Patellar instability is a complex pathoanatomical phenomenon that requires an intricate understanding in order to properly treat patients. Often, the etiology of this entity is multifactorial, combining a series of physiologic and anatomic variables. A thorough history and physical as well as correct radiographic examinations are critical in both establishing the diagnosis and instituting the correct treatment. Non-operative management of recurrent instability has a high failure rate. Current operative techniques have been shown to be instrumental in correcting anatomic abnormalities, reducing symptoms of instability, and giving patients an appropriate chance of returning to their previous level of activity.