Recurrent Pediatric Patellofemoral Instability-Beyond the MPFL

Abstract

Pediatric patellofemoral instability is a 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, sporadic recurrent dislocation, obligatory dislocation in flexion, or even fixed dislocation in severe or syndrome-associated cases. 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. When treating pediatric patellofemoral instability, it is important to understand the benefits and limitations of nonoperative management. We further recognize the challenges imparted by the anatomy of the skeletally immature knee, specifically with regards to the physis, when considering surgical treatment. The purpose of this paper is to review our approach to first time dislocations and non-fixed recurrent patella femoral instability. Key Concepts: • Nonoperative management of first-time patellofemoral dislocations consists of a regimented rehabilitation and return to play protocol. • In the skeletally immature patient, medial patellofemoral ligament reconstruction requires close attention to the anatomic proximity of the medial distal femoral physis. • Guided growth to correct genu valgum in isolation or in combination with other stabilizing procedures can treat patellofemoral instability in immature patients. • Concomitant chondral or osteochondral injury must be recognized and may require surgical treatment. • In severe cases of patellofemoral instability such as obligatory dislocation in flexion, an algorithmic treatment approach which considers individual patient factors as well as intraoperative findings should be implemented.