Patent ID: 8187335

Claim:
A posterior stabilized orthopaedic knee prosthesis comprising: a femoral component including (i) a pair of spaced apart condyles defining an intracondylar notch therebetween, at least one of the pair of spaced apart condyles having a condyle surface curved in the sagittal plane and (ii) a posterior cam positioned in the intracondylar notch; and a tibial bearing including (i) a platform having a bearing surface configured to articulate with the condyle surface of the femoral component and (ii) a spine extending upwardly from the platform, wherein the condyle surface of the femoral component (i) contacts the bearing surface at a first contact point on the condyle surface at a first degree of flexion, (ii) contacts the bearing surface at a second contact point on the condyle surface at a second degree of flexion, the second degree of flexion being greater than the first degree of flexion and in the range of about 0 degrees to about 50 degrees, and (iii) contacts the bearing surface at a third contact point on the condyle surface at a third degree of flexion, the third degree of flexion being greater than the second degree of flexion and less than about 90 degrees, wherein (i) the condyle surface has a first radius of curvature in the sagittal plane at the first contact point, a second radius of curvature at the second contact point, and a third radius of curvature at the third contact point, and (ii) the third radius of curvature is greater than the second radius of curvature by at least 0.5 millimeters, and wherein the posterior cam of the femoral component initially contacts the spine of the tibial bearing after the second degree of flexion at a fourth degree of flexion, the fourth degree of flexion being no greater than about 10 degrees more than the third degree of flexion.