Andrish, Jack T. MD
Injury and subsequent insufficiency of the medial patellofemoral ligament (MPFL) has been described as the «essential lesion» of recurrent lateral dislocation of the patella. As the biomechanical role of the MPFL has become better understood, techniques for surgical reconstruction are being popularized. Unfortunately, to date, there is no scientific evidence to support one technique over another. However, we do have sound information regarding the biomechanics of the MPFL. The primary purpose of the MPFL is to help guide the patella safely into the confines of the trochlea during the initial 20 to 30 degrees of knee flexion. Before undertaking surgical reconstruction of the MPFL, a thorough understanding of the anatomy of the retinacular layers of the medial side of the knee, as well the recognition of the biomechanics of the MPFL, is mandatory. The MPFL is under greatest tension with the knee in full extension and maintains this tension throughout the initial 30 to 40 degrees of flexion. To avoid overconstraint of the knee, the placement of fixation upon the femur is critical. The femoral attachment site should preferably be anatomic but never proximal to the native origin between the medial epicondyle and the adductor tubercle as this can lead to postoperative stiffness and/or ultimate graft failure.
Techniques in Knee Surgery. 5(2):121-127, June 2006.