Patent ID: 9168145
Filing Date: 2015-10-27
Classification: A61F

Abstract:
1. 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 of about 0 degrees, (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 60 degrees to 75 degrees, (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 in the range of 75 degrees to 90 degrees, (iv) the condyle surface of the femoral component contacts the bearing surface at a fourth contact point on the condyle surface at a fourth degree of flexion, the fourth degree of flexion being greater than the third degree of flexion, wherein the condyle surface (i) 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, a third radius of curvature at the third contact point, and a fourth radius of curvature in the sagittal plane at the fourth contact point, (ii) a first curved surface section defined between the first contact point and the second contact point, the first curved surface section having a decreasing, non-constant radius of curvature, and (iii) the ratio of the fourth radius of curvature to the third radius of curvature is in the range of 0.7 to 1.15, wherein the posterior cam of the femoral component initially contacts the spine of the tibial bearing at a degree of flexion between the second degree of flexion and the third degree of flexion, wherein the second radius of curvature is different from the first radius of curvature, wherein the third radius of curvature is different from the first radius of curvature and the second radius of curvature, and wherein the fourth radius of curvature is different from the first radius of curvature, the second radius of curvature, and the third radius of curvature, and wherein the posterior cam of the femoral component includes a concave cam surface and a convex cam surface that are positioned toward a posterior side of the femoral component.