Effect of joint laxity on damage prediction in knee prostheses using a multibody dynamics methodology

The present study aims to develop a dynamics model based on the multibody dynamics methodology to study the influence of ligamentous insufficiency on damage estimation, i.e. wear and creep, of total knee arthroplasty. The anterior cruciate ligament is assumed sacrificed during the knee surgery while the medial and lateral collateral ligaments (MCL and LCL) and posterior cruciate ligament (PCL) stabilize the knee. Insufficient PCL leads to an increase in linear wear rates observed on the medial condyle whereas insufficient MCL-LCL results in the maximum damage. Including both insufficient MCL-LCL and PCL lead to lower linear damage than MCL-LCL alone. It can be concluded that the ligamentous insufficiency affects damage observed on the polyethylene bearing surface but an increase in laxity does not necessarily lead to an increase in damage.