A total knee replacement system includes a tibial component having a tibial post with a posterior portion, and a femoral component with medial and lateral condylar protrusions forming separated bearing surfaces configured to articulate with the tibial component. In one disclosed embodiment the posterior portion of the tibial post has a concave surface in the sagittal plane and a convex surface in the transverse plane, and the femoral component includes an intercondylar femoral cam mechanism configured to articulate with the posterior surface of the tibial post. The femoral cam mechanism may include an intercondylar bridging structure with distinct bars or interconnected structural elements providing convex and concave distal surfaces in the sagittal plane, and a concave surface in the transverse plane to facilitate rotation of the femoral component relative to the tibial component in the transverse plane.
