Troubleshooting the Femoral Attachment During Medial Patellofemoral Ligament Reconstruction

The medial patellofemoral ligament (MPFL) has been recognized as an important soft tissue restraint in preventing lateral patellar translation. As many patients with acute or chronic patellar instability will have a deficient MPFL, reconstruction of this ligament is becoming more common. Appropriately, significant research has been undertaken regarding graft biomechanics and techniques, as intraoperative errors in graft placement often result in poor patient outcomes. Although the research has not answered all of the dilemmas encountered during reconstruction, publications consistently emphasize the importance of re-establishing an anatomic femoral attachment. The purpose of this study was to briefly review the current literature on MPFL reconstruction. Graft selection and patellar graft attachment and fixation are discussed, but the main focus is the femoral attachment as this is where most errors are seen and, unfortunately, where getting it right appears to matter the most. Using a sawbones knee model, the concepts of an MPFL graft that is ‘‘high and tight’’ or ‘‘low and loose’’ are presented, with the goal of providing physicians with intraoperative tools to adjust an incorrectly placed femoral MPFL attachment. This model is also used to justify the recommendation of graft fixation in 30 to 45 of knee flexion.