Specimen-Specific Verification of Predicted TKR Mechanics During Simulated Deep Flexion Loading Conditions

Verified computational models of total knee replacement serve as the primary design-phase tool for parametric analysis of implant geometry. Previously, dynamic finite element models of the Kansas Knee Simulator (KKS) were developed and tibiofemoral (TF) and patellofemoral (PF) kinematic predictions were verified by comparison with experimental measurements [1,2]. In this prior work, the implants were mounted in metallic fixtures to assess the ability of the model to accurately predict the TF and PF kinematics without the additional complexity of variable cadaver specimens and soft-tissue constraint. The next step in the systematic model verification procedure was to verify kinematic predictions with multiple specimen-specific models. Specifically, the objectives of the present study were: 1) to develop an explicit finite element (FE) model of the KKS capable of recreating experimental loading protocols for a deep knee bend activity and 2) to verify predicted six degree-of-freedom (DOF) TF and PF kinematics of two cruciate retaining (CR) and two posterior stabilized (PS) implanted specimen-specific models with deformable, wrapping soft tissue constraint.