Orthopaedic femoral component having controlled condylar curvature

摘要

An orthopaedic knee prosthesis includes a femoral component having a condyle surface. The condyle surface is defined by one or more radii of curvatures, which are controlled to reduce or delay the onset of anterior translation of the femoral component relative to a tibial bearing.

主权项

1. An orthopaedic knee prosthesis comprising:
a femoral component having a condyle surface curved in the sagittal plane; and a tibial bearing having a bearing surface configured to articulate with the condyle surface of the femoral component, wherein the condyle surface (i) contacts the bearing surface at a first contact point on the condyle surface at a first degree of flexion equal to 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 in the range of 10 degrees to 75 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, 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 in the sagittal plane at the second contact point, and a third radius of curvature in the sagittal plane at the third contact point, and (ii) the second radius of curvature is greater than the first radius of curvature by at least 0.5 millimeters, and wherein the third radius of curvature is less than the second radius of curvature such that a curved surface section having a non-constant radius of curvature is defined between the first contact point and the third contact point and is configured to reduce paradoxical anterior translation of the femoral component.