Patellofemorale Instabilität und retropatellarer Knorpelschaden: MPFL + X?

This article demonstrates the clinical picture of complex patellofemoral instability with a laterally riding patella and retropatellar cartilage damage in a young male patient. The complaints were persistent pain and maltracking of the patella in a knee that had already been operated on several times with initial medialization by osteotomy of the tibial tuberosity and minced cartilage retropatellar cartilage repair and additional medial patellofemoral ligament (MPFL) reconstruction. As part of a general reassessment a basic objective analysis of the bony alignment parameters is performed. A physiotherapeutic evaluation of the dynamic stabilizers is also included. In this case of a pre-existing genu valgum without torsional pathology but pronounced trochlear dysplasia, a coronal axis correction with trochleoplasty and lateral soft tissue lengthening surgery were performed. In accordance with the postulated hip-down model, the Q angle was improved and thus the traction vector of the quadriceps and reduction of the lateral contact pressure of the patella The trochleoplasty leads to patellofemoral stabilization, which the initial tuberosity medialization and subsequent MPFL reconstruction did not achieve.