Medial Patellofemoral Ligament Tear Associated with an Intra-articular Axial Spilt Osteochondral Fracture of the Lateral Femoral Condyle: a "Knee Trap-door" Fracture

J Orthop Case Rep. 2023 Aug;13(8):52-56. doi: 10.13107/jocr.2023.v13.i08.3814.

Abstract

Introduction: Medial patellofemoral ligament (MPFL) prevents lateral dislocation of the patella and acts as a major stabilizer. The tear could be associated with osteochondral avulsion fractures; however, intra-articular split fractures are not seen. Here, we present one unusual case of such a presentation.

Case report: A 16-year-old male presented with a history of recurrent patellar dislocation and inability to bear weight following the last episode. The patient was diagnosed with an MPFL tear with an unusual intra-articular femoral condyle split fracture. The case had significant improvement in functional scores post-surgery.

Conclusion: In physically active populations, twisting of the knee could result in an MPFL tear, leading to recurrent patellar dislocation. The treatment remains ligament reconstruction, open, or arthroscopic. Associated intra-articular fractures are very rare with such injuries and need to be addressed due to the high rate of non-union.

Keywords: Herbert screw fixation; MPFL tear; Medial patella-femoral ligament; osteochondral fracture.

Publication types

  • Case Reports