Gait cycle comparions of cruciate sacrifice for total knee design.-explicit finite element

Abstract

Joint kinematics and contact mechanics dictate the success of current total knee replacement (TKR) devices. Computational contact prediction is a feasible way of evaluating new TKR designs prior to physical testing and implementation. Previous finite element (FE) knee models have generally been used to predict stresses on contact areas and/or areas subjected to static or quasi-static loading. Explicit dynamic FE analyses have recently been used to effectively predict TKR kinematics and contact mechanics during dynamic loading conditions. In this study, we compared the functional load transmission and kinematic performance of two posterior-stabilized designs, standard and post-cam TKR versions, over a standardized loading cycle using three-dimensional contact finite element analysis. Our objective was to develop and experimentally validate an explicit FE TKR model that incorporates femoral-bearing articulations. Finite element-based computational contact pressure predictions were applied to gait cycles using both force-controlled and displacement-controlled inputs. A standard prosthesis showed a reduction in contact pressure compared with post-cam prosthesis components, as it redistributed the knee motion to two articulating interfaces with more linear motions at each interface. In this FE analysis, the wear of TKR bearings was dependent on kinematics at the articulating surfaces and on prosthesis design.