Computational study on lateral and medial wear characterization in knee implants by a multibody dynamic system

Wear is one of the main mechanical factors that limits the survival of total knee replacements (TKRs) and it is known to be highly dependent on the local kinematics of the knee joint. In this study, an analytical wear model was coupled to a multibody dynamic model to obtain wear distribution at the lateral and medial contact plateaus of different TKRs. The major aim was to analyze if wear distribution on the contact plateaus can be an indicator of elevated tibiofemoral misalignment which can lead to rapid TKR failure. For the multibody dynamic simulations, commercial and prototype TKR geometries were used, coupled with an augmented Archard’s law. Squat movement was chosen due to its importance both in sports and in everyday life. As a conclusion, a new parameter, denoted as wear imbalance, is introduced, which can indicate whether a TKR, due to its geometrical features, is prone to be subjected to elevated wear and failure.