Pediatric Patellofemoral Instability: Beyond the MPFL Current Concept Review

Abstract

Pediatric patellofemoral instability is an increasingly common and debilitating problem. In recent years, there has been an improvement in diagnostic capabilities and greater knowledge of unique pediatric patellofemoral anatomy and pathophysiology. The spectrum of disease varies from a single traumatic dislocation, to recurrent dislocation, to obligatory dislocation in flexion or even fixed dislocation in severe or syndrome-associated cases. When treating pediatric patellofemoral instability, it is important to understand the benefits and limitations of nonoperative management. It is important to recognize the challenges imparted by the anatomy of the skeletally immature knee, specifically with regards to the physis, when considering surgical treatment.  One must have a thorough understanding of common anatomic and pathophysiologic contributors to patellofemoral instability, such as coronal or axial plane malalignment, and concomitant osteochondral injury. For the very severe cases such as obligatory dislocation in flexion, special techniques may be required to achieve stability of the patellofemoral joint.