The Effect of Tibial Tuberosity Medialization and Lateralization on Patellofemoral Joint Kinematics, Contact Mechanics, and Stability

Background:Tibial tuberosity (TT) transfer is a common procedure to treat patellofemoral instability in patients with elevated TT–trochlear groove (TG) distances. However, the effects of TT lateralization or medialization on patellar stability, kinematics, and contact mechanics remain unclear.Hypothesis:Progressive medialization and lateralization will have increasingly adverse effects on patellofemoral joint kinematics, contact mechanics, and stability.Study Design:Controlled laboratory study.Methods:Eight fresh-frozen cadaveric knees were placed on a testing rig, with a fixed femur and tibia mobile through 90° of flexion. Individual quadriceps heads and the iliotibial band were separated and loaded with 205 N in anatomic directions using a weighted pulley system. Patellofemoral contact pressures and patellar tracking were measured at 0°, 10°, 20°, 30°, 60°, and 90° of flexion using pressure-sensitive film behind the patella and an optical tracking system. The intact knee was measured with and without a ...