| 主权项 |
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, the first degree of flexion being less than about 30 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 in the range of 35 degrees to 90 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 (iv) contacts the bearing surface at a plurality of contact points between the first contact point and the second contact point when the femoral component is moved from the first degree of flexion to the second degree of flexion, wherein the posterior cam of the femoral component contacts the spine of the tibial bearing 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, wherein each contact point of the plurality of contact points is defined by a ray extending from a common origin to the respective contact point of the plurality of contact points, each ray having a length defined by the following polynomial equation:
rθ=(a+(b*θ)+(c*θ2)+(d*θ3)), wherein rθ is the length of the ray defining a contact point at θ degrees of flexion, a is a coefficient value between 20 and 50, and b is a coefficient value in a range of 0.00<b<0.30, wherein (i) c is a coefficient value between −0.010 and 0.00 and (ii) d is a coefficient value between −0.00015 and 0.00, wherein the condyle surface in the sagittal plane has a first radius of curvature at the first contact point and a second radius of curvature at the second contact point, the second radius of curvature being less than the first radius of curvature. |
