519 - Combined Medial Patellofemoral Ligament Reconstruction and Distal Femur Osteotomy for Recurrent Patella Instability: A Case Report

Case Diagnosis: Recurrent Patella Instability of the Right Knee

Case Description: A 15-year-old female presented with right knee pain and experienced spontaneous patella dislocation (PD). Initial treatment involved conservative management with a J brace and physical therapy. However, recurrent PDs persisted, impacting her participation in recreational activities. Imaging studies revealed mild valgus deformity, a dysplastic femoral trochlea, and a 15 mm tibial tubercle-trochlear groove distance. The patient underwent right medial patellofemoral ligament (MPFL) reconstruction using a semitendinosus allograft and a distal femur open-wedge osteotomy with internal fixation. Post-surgery, she followed a standardized rehabilitation protocol.

Discussions: Patella dislocations account for 3% of all knee injuries, with a higher incidence in adolescent females. A history of PD increases the risk of ongoing instability. The MPFL is the primary restraining force for the patella, often addressed surgically when conservative methods fail. Studies suggest that concurrent anatomical misalignment, most significantly genu valgum, can yield unsuccessful MPFL repair/reconstruction. Parameters regarding the q-angle and tibial tubercle-trochlear groove distance at which bony misalignment should be addressed, and the modality for management, have not been standardized in literature. Nevertheless, correcting valgus deformity alongside MPFL reconstruction may improve outcomes.



In this case, a 15-year-old female with multiple risk factors for recurrent PDs underwent correction of genu valgum using a less explored distal femoral open-wedge approach. This simultaneous correction aimed to reduce the risk of isolated MPFL reconstruction failure. The patient made significant progress during rehabilitation, resulting in functional improvement and a safe discharge home.

Conclusions: This case underscores the effectiveness of combining MPFL reconstruction with distal femur open-wedge osteotomy in managing young patients with recurrent patella instability. After surgery, the patient was able to successfully participate in rehabilitation. Future studies can work toward standardizing parameters for correcting anatomical misalignment to prevent isolated MPFL reconstruction failure and improve functional outcomes.