Abstract: Reconstruction of the medial patellofemoral ligament (MPFL) for recurrent patellar dislocation provides
significant improvements in knee function. However, various complications have been reported, with most attributed to incorrect positioning of anchoring sites for the reconstructed MPFL and inappropriate graft tension. Patellofemoral congruence at 30 of flexion on arthroscopy was therefore controlled using devices able to modify the length of the reconstructed MPFL. This was done under circumstances of external rotation of the knee joint and electrical stimulation of the quadriceps with the purpose of maintaining the patella in a lateral shift. Advantages of this technique include completely controllable correction on arthroscopy under the worst patellofemoral congruence induced by external rotation of the knee joint and electrical stimulation of the quadriceps at 30 of flexion of the knee joint; in other words, voluntary determination of lateral shift during arthroscopy.