Abstract: A semiconstrained prosthetic knee for surgical replacement of a dysfunctional knee includes a tibial platform, a movable bearing element, and a femoral component. The prosthetic knee has an adjusted center of internal/external rotation to achieve at least one advantage such as enhancing performance, minimizing wear, compensating for wear and mimicking the natural center of internal/external rotation of the natural joint.

Abstract: A semiconstrained prosthetic knee for surgical replacement of a dysfunctional knee includes a tibial platform, a movable bearing element, and a femoral component. The femoral component includes a polycentric convex bearing which slidably engages a movable bearing. The superior surface of the bearing element is designed to congruently slidably engage the inferior surface of the bearing portion of the femoral component throughout the flexion/extension range of the knee. The superior surface of the tibial platform is generally flat and includes at least one protrusion for controlling the movement of the bearing element. A stabilized prosthetic knee also includes a posterior stabilization member and may further include an anterior stabilization member upon the bearing element. The femoral component and the bearing element articulate in at least two radii of curvature and are also provided with an additional articulation surface and a complementary bearing surface.

Abstract: A semiconstrained prosthetic knee for surgical replacement of a dysfunctional knee includes a tibial platform, a movable bearing element, and a femoral component. The femoral and tibial components are typically constructed of a cobalt-chromium alloy and each includes an extension for securing the component to the bone. The femoral component includes a polycentric convex bearing which slidably engages a movable bearing, typically constructed of high molecular weight polyethylene. The superior surface of the bearing element is designed to congruently slidably engage the inferior surface of the bearing portion of the femoral component throughout the flexion/extension range of the knee. The inferior surface of the femoral component is generally convex with two or more offset portions of varying radii of curvature matching complimentary superior surfaces of the bearing element. The inferior surface of the femoral component may have more than one radii of curvature at different points along the convex surface.