Influence of tibial bearing curvatures of a customised total knee implant on squatting motion and loads.

A range of preliminary designs of customised total knee implants (CTKIs) was created by resurfacing the distal femur and applying different tibial bearing surface curvatures. These were then compared with a scaled off-the-shelf symmetric total knee implant (STKI). To evaluate the biomechanical performance, a dynamic knee simulation model was created with patient-specific muscle and ankle joint loads calculated from an OpenSim musculoskeletal model. Simulation results showed the transverse curvatures of the tibial bearing surface influenced femoral mediolateral translation, while its longitudinal curvatures affected femoral adduction. Compared to the STKI, the CTKIs could restore patient knee function.