Patellofemoral Pain Disorders: Evaluation and Management.

Patellofemoral pain disorders can be difficult to diagnose. Careful attention to the history and physical examination is central to accurate diagnosis. Standardized office radiographs are sufficient in most cases. Computed tomography of the patellofemoral joint (precise midpatellar transverse images through the posterior femoral condyles with the knee at 15, 30, and 45 degrees of knee flexion) will provide valuable objective information regarding subtle abnormalities of patellar alignment. Magnetic resonance imaging and radionuclide scanning may be helpful in selected cases. By differentiating between rotational (tilt) and translational (subluxation) components of patellar malalignment, the clinician will be better able to prescribe appropriate treatment. It is also extremely important to localize and quantitate articular and retinacular abnormalities. While nonoperative treatment is usually successful, surgery is sometimes required. Lateral release will relieve tilt and associated pain in the lateral retinaculum. Realignment of the extensor mechanism, usually at the level of the tibial tubercle, is necessary to control lateral tracking (subluxation) of the patella. If there is lateral or distal medial articular damage related to chronic lateral tilt and/or subluxation, shift of the tibial tubercle will help to unload damaged cartilage while realigning the extensor mechanism.