A Forward Dynamics Methodology to Study Nonlinear Dynamics and Wear of Total Knee Arthroplasties

Abstract

Relative motion between the knee components, dynamic loading, and contact stresses in the knee joint play vital roles in the development and progression of wear occurrence in total knee arthroplasty (TKA), which can ultimately cause the implant to fail and require revision [1,2]. Therefore, developing anatomical-based models to study the kinetic and kinematic behavior of substructures of TKAs while taking the real geometry and material properties of knee components is essential. Having a look at the scientific history of knee joint models, the pioneering successful work comes back to the anatomical and sophisticated three-dimensional (3D) quasistatic model Wismans et al. developed in 1980 [3]. During the last decades, many studies were carried out employing quasi-static knee models [4,5]. However, quasistatic models do not allow to consider inertial loads and detailed studies of such a complex joint to determine, e.g., the tribological behavior of the joint [6,7]. Much of the mathematical dynamic approaches of the joint available in the literature are two-dimensional, considering motions in the sagittal plane only [8]. One of the very first successful attempts to determine the 3D dynamic solution of knee joint was carried out by Abdel-Rahman and Hefzy [6], while the model did not account for the deformation of the articular surfaces and the real geometry of the tibial insert. Later, that model was improved by Caruntu and Hefzy [7] to take into account deformable contact at the articular surfaces. Although much of the available knee joint dynamic models just focused on the joint rather than whole body simulation, Piazza and E. Askari ( )