Rehabilitation and nonoperative treatment of patellar instability.

Patellofemoral instability can be a difficult condition for clinicians to manage. Differentiation needs to be made as to whether the problem is an acute injury where a traumatic incident has usually precipitated the dislocation or whether the problem is a recurrent instability where the patellofemoral joint is unstable during everyday activities. This review defines instability, discusses the factors affecting instability, and provides assessment procedures and nonoperative intervention strategies for the clinician.