Autologous semitendinosus meniscus graft significantly improves knee joint kinematics and the tibiofemoral contact after complete lateral meniscectomy

Purpose The purpose of this study was to investigate the potential of a doubled semitendinosus (ST) and a single gracilis tendon (GT) lateral meniscus autograft to restore the knee joint kinematics and tibiofemoral contact after total lateral meniscectomy (LMM).Methods Fourteen human knee joints were tested intact, after LMM and after ST and GT meniscus autograft treatment under an axial load of 200 N during full range of motion (0 degrees-120 degrees) and four randomised loading situations: without external moments, external rotation, valgus stress and a combination of external rotation and valgus stress using a knee joint simulator. Non-parametric statistical analyses were performed on joint kinematics and on the tibiofemoral contact mechanics.Results LMM led to significant rotational instability of the knee joints (p < 0.02), which was significantly improved after ST autograft application (p < 0.04), except for knee joint flexions > 60 degrees. The GT autograft failed to restore the joint kinematics. LMM significantly increased the tibiofemoral contact pressure (p < 0.03), while decreasing the contact area (p < 0.05). The ST autograft was able to restore the contact mechanics after LMM (p < 0.02), while the GT replacement displayed only an improvement trend.Conclusion The doubled ST lateral meniscus autograft improved the knee joint kinematics significantly and restored the tibiofemoral contact mechanics almost comparable to the native situation. Thus, from a biomechanical point of view, ST meniscus autografts might be a potential treatment alternative for patients who are indicated for meniscus allograft transplantation.