Tibial Tubercle Osteotomy: A Biomechanical Comparison of Two Techniques

Abstract Purpose The purpose of this study was to determine whether a modified step-cut tibial tubercle osteotomy (Maquet-Fulkerson) hybrid) might produce comparable or better results than a standard oblique anteromedialization tibial tubercle osteotomy (Fulkerson type) and thus warrant the surgical need for additional cuts. Methods Six pairs of cadaveric knees were evaluated prior to and after tibial tubercle osteotomies. Simulation was done via a shallow knee bend simulator through 20 to 70 degrees of knee flexion for the intact specimens and following the surgical procedures. The variables tested were trochlear contact forces and pressures and patellar motion. Results Testing showed a decreased force (P = 0.027), peak contact pressure (P = 0.01) and contact area (P = 0.034) on the lateral trochlea of the femur for both types of osteotomies. There was no significant difference in the lateral femoral peak pressure or in the medial femoral peak pressure between the oblique cut and the step-cut. Also, there was no difference in patellar motion after either procedure. Conclusion We conclude that both osteotomies decrease lateral patellofemoral trochlear pressure. The oblique osteotomy may decrease lateral pressure to a greater extent. Regarding biomechanical testing, there was no demonstrable advantage to performing a step-cut osteotomy.