Anatomic Reconstruction of the Patellofemoral Joint

The investigators posit that it would be advantageous to reproduce the height of the entire patellofemoral joint in order to maintain the lever arm of the quadriceps mechanism at its preoperative level. Failure to do this may cause the quadriceps mechanism to be inefficient. For example the quadriceps mechanism would have to work harder if the total patellofemoral (PF) height is diminished. Alternatively, diminished motion or increased patellar strain may occur if the overall PF height is increased. The investigators theorize that either of these sizing errors could lead to anterior knee pain. The purpose of this study is to compare the clinical outcomes between two surgical techniques: 1) a technique of reproducing the total PF joint on both sides of the articulation (Group 1) and 2) the traditional technique of reproducing only the patellar thickness on one side of the joint (Group 2).