Patent ID: 8734522

Claim:
An orthopaedic knee prosthesis comprising: a tibial bearing configured to be coupled to a tibial tray, the tibial bearing having a platform and a spine extending upwardly from the platform, the spine having a posterior side including a concave cam surface and a convex cam surface, the concave cam surface being concavely curved in the sagittal plane and convexly curved in the transverse plane, and the convex cam surface being convexly curved in the sagittal plane and convexly curved in the transverse plane; and a femoral component configured to articulate with the tibial bearing, the femoral component including (i) a pair of spaced apart condyles defining an intracondylar notch therebetween and (ii) a posterior cam positioned in the intracondylar notch, the posterior cam including a concave cam surface and a convex cam surface that are positioned toward a posterior side of the femoral component, the concave cam surface being concavely curved in the sagittal plane and the convex cam surface being convexly curved in the sagittal plane, wherein (i) the posterior cam is spaced apart and out of contact from the spine at a flexion of approximately zero degrees, (ii) the concave cam surface of the posterior cam initially contacts the convex cam surface of the spine during a first range of flexion that is greater than zero degrees, and (iii) the convex cam surface of the posterior cam initially contacts the concave cam surface of the spine during a second range of flexion that is greater than the first range of flexion.