Evaluation of compressive and shear joint forces on medial and lateral compartments in knee joint during walking before and after medial open-wedge high tibial osteotomy

The main principle of open-wedge high tibial osteotomy (HTO) is to shift the weight-bearing line of the knee joint in order to decompress the degenerated compartment and delay osteoarthritis (OA). In this study, the resultant contact forces on the medial compartment, lateral compartment, and total tibiofemoral joint were analyzed during gait for five OA patients before and after HTO in order to fully understand the effect and mechanism of HTO for the OA knee. The compressive, lateral-medial shear, and anteriorposterior shear force components of the joint force, as well as the ratio of the medial contact force to the lateral contact force, were investigated using inverse dynamic and multi-body dynamic models. Medial open-wedge HTO improved the balance of medial and lateral contact forces on the tibiofemoral joint, which demonstrated the purpose of HTO provided by clinical studies and the outcomes of a computational study. In addition to the compressive contact force, the lateral-medial shear force was also reduced during the stance phase of walking after HTO. The technology in this study provides a fundamental tool to evaluate the outcomes of HTO by considering daily and sports activities.