Anteromedializing tibial tubercle osteotomy does not restore femorotibial and patellofemoral pressures to native values in a human biomechanical model with increased femoral anteversion.

PURPOSE: The aim of this study was to evaluate the biomechanical consequences of performing an anteromedializing tibial tubercle osteotomy on a cadaveric knee model with increased femoral anteversion.

METHODS: A controlled biomechanical study was performed on 16 human cadaveric knees. Intra-articular pressures were measured under four conditions. The first group was the native knee (n = 16). Subsequently, the sample was divided into two equal groups: a group in which 30 degrees of internal femoral rotation was experimentally induced (n = 8), and a group in which a Fulkerson osteotomy was performed (n = 8). Finally, the group in which an internal rotation of 30 degrees was experimentally induced underwent a Fulkerson osteotomy (n = 8). Measurements were obtained at 0°, 30°, 60° and 90° of knee flexion under a simulated weight-bearing squat condition using a 1000 N ground reaction force combined with independent quadriceps (218 N) and hamstring (80 N) loading. Patellofemoral and tibiofemoral compartments were analysed using intra-articular pressure sensors.

RESULTS: Compared with the native knee, internal femoral rotation significantly increased lateral patellofemoral pressure (1.220 ± 0.016 vs. 1.342 ± 0.032 MPa at 30° of flexion; p = 0.05) and lateral tibiofemoral pressure (1.110 ± 0.020 vs. 1.489 ± 0.054 MPa at 90° of flexion; p = 0.004). The anteromedialization of the tibial tubercle partially reversed those changes. However, the technique failed to restore the pressure distribution to native values (all p < 0.05).

CONCLUSION: Our findings indicate that while anteromedialization of the tibial tubercle partially mitigates the biomechanical alterations induced by increased internal femoral torsion, it does not fully restore native joint pressure distribution. These findings suggest that isolated distal realignment may be insufficient in the presence of significant rotational deformity and that surgical strategies should also address proximal rotational abnormalities to optimise joint loading.

LEVEL OF EVIDENCE: NA.