Prosthetic knee joint with enhanced posterior stabilization and dislocation prevention features

A knee joint prosthesis comprising:

• a femoral component having a superior surface configured for mounting to a femur, an inferior articular bearing surface which includes medial and lateral convex condyles, a posterior notch extending anteriorly into a posterior face of the femoral component, and continuously between the superior and inferior surfaces, said notch being defined by substantially parallel spaced apart medial and lateral walls projecting in a superior direction from the superior surface and by medial and lateral flanges projecting toward one another from locations on the respective medial and lateral walls adjacent the inferior articular bearing surface of the femoral component, said flanges of said femoral component having inferior surfaces substantially conforming to shapes defined by said convex condyles, said flanges further having arcuately concave superior bearing faces;
• a tibial component;
• and
• a bearing disposed between the femoral and tibial components, the bearing having a superior bearing face in articular bearing engagement with the inferior articular bearing surface of the femoral component, said bearing further including a post projecting from the superior face thereof and slidably disposed in the posterior notch of the femoral component, said post including medial and lateral cam projections spaced from said superior bearing face of said bearing, said flanges of said femoral component being between the cam projections and the superior bearing face of the bearing, the medial and lateral cam projections of the bearing have arcuately convex inferior bearing surfaces for bearing engagement against the arcuately concave superior bearing surface of the flanges of the femoral component for resisting valgus-varus moments applied to the prosthesis, the arcuately convex inferior bearing surfaces each defining a curvature smaller than the arcuately concave superior bearing surfaces of the flanges to enable relative anterior-posterior movement between the femoral component and the bearing.