Sagittal profile of the femoral condyles and its application to femorotibial contact analysis.

Measurements of the sagittal profiles of the articular surfaces of 24 femoral condyles were performed using a laser range finder. An algebraic algorithm was developed to reconstruct the measured sagittal profiles with simple geometry. In particular, it has been shown that a two-circular-arc model provides a very accurate reconstruction of the actual profiles in the femorotibial contact region. The average sagittal profile was used for a femorotibial contact analysis of TKA implants. The contact analysis was performed by using a rigid-body-spring model extended to the case of nonlinear force-deformation behavior of the tibial polyethylene component.