Medial Patellofemoral Ligament (MPFL) Reconstruction

This procedure reconstructs and restores an incompetent and damaged MPFL when nonsurgical treatments, including physical therapy and exercises, bracing, and temporary modifications of sporting activity have been inadequate.  The approach emphasizes anatomical precision by accurately restoring the native tissues of the knee without constraining or overloading the patellofemoral joint.  One of the tenets of successful MPFL reconstruction is identification of the isometric point on the femur, where the new MPFL is fixed so that the tension on the new MPFL is identical through a range of motion.  This is performed by careful radiographic (X-Ray) analysis based on anatomical studies (1) and is confirmed during surgery as the knee is moved throughout flexion and extension.

MPFL reconstruction is the preferred treatment for a dislocating knee, especially in athletes, because it minimizes downtime with a relatively fast return to sports and running, compared with other knee procedures such as ACL reconstruction.  The procedure is performed through small incisions on the medial (inner) portion of the knee.  Sometimes arthroscopic evaluation and treatment of cartilage injuries is used before and after the ligament restoration portion.

In this procedure the MPFL is reconstructed or made anew, where the tissue is taken from another source.  The new ligament is called a graft where tissue is transferred to a new location.  Typically, the most reliable method of graft source is from a cadaver, in part because it minimizes the invasiveness of the harvesting of tissue from a different location around your knee and simplifies the recovery.  Utilization of cadaver tissue (allograft) is far more common with MPFL than in ACL reconstruction because the tissue is simply a checkrein, meaning it holds the position of the knee without sustaining very large tensile forces inside the joint like the ACL does.  Despite this, some patients prefer to use their own tissue which is also an option and discussed with you prior to surgery.

The procedure is performed through two small incisions, one over the medial patella and one near the adductor tubercle where the natural MPFL attaches.  On the patellar side, the graft is fixated using modern minimally invasive all-suture anchors, which minimizes the risk of patellar fracture.  On the femoral side, the graft is fixated at Schöttle’s point with a biocomposite interference screw, ensuring appropriate isometry through a range of motion (1).  Prior to final fixation, the graft is appropriately tensioned with the knee in just slight flexion, so as to appropriately secure stability without overconstraining or overloading the patellofemoral joint.

The procedure is performed as an outpatient, and crutches and a brace are recommended for approximately four weeks during healing.  Early motion exercises are initiated as soon as soreness subsides within a few days under the direction of a physical therapist.  Full daily activities and normal walking is resumed once the brace is discontinued, and running is started at approximately 3 months during the strengthening phase of recovery.  Full sporting activity is resumed between 3-5 months postoperatively.