Computational evaluation of the effect of femoral component curvature on the mechanical response of the UHMWPE tibial insert in total knee replacement implants

Total knee replacement (TKR) surgery is done on individuals with end-stage osteoarthritis to restore knee function and alleviate joint discomfort. There have been recent developments in the design of customized implants based on patient-specific data obtained from MRI scans and subsequent image processing techniques. Here curvature of the femoral component plays an important role in effective implant design. Therefore, the objective here is to investigate the influence of this curvature of the femoral component on the mechanical response of the bearing component. A 3D finite element knee implant model with a circular and an elliptical femoral component is developed and investigated for gait kinetics and kinematics. Responses such as contact pressure, stresses, strains, and wear produced on the tibial insert are estimated throughout the gait cycle. These findings suggest that the elliptical femoral component generates less contact pressure on the tibial insert than its circular counterpart. It is also inferred that too much variation in this curvature is not recommended as it may affect the patient's comfort level. In addition, the wear of the tibial insert is computed based on the contact pressure created by both knee implant models. Our study suggests an optimum value for the curvature and the comfort level of the patients over the existing knee implant designs.