Influence of friction on knee internal rotation in patients with knee arthroplasties during activities of daily living

In recent decades, knee arthroplasty (KA) succeeded to improve patients’ clinical scores and gait patterns [1]. However, to date, studies primary focused on biomechanical analysis of level walking with total knee arthroplasty (TKA) patients. The investigation of neuromuscular more challenging activities of daily living (ADL) like stair climbing and especially ramp negotiation was partly neglected [2]. Furthermore, non-sagittal plane parameters have mostly not been considered, whereby the evaluation of e.g. transverse plane kinematics and kinetics may reveal potential differences between various endoprosthetic designs. Additionally, frictional forces transmit appreciable shear between the femoral component and the tibial polyethylene insert, potentially contributing to axial knee rotational constraints and implant loosening [3]