Prosthesis for simulating natural kinematics

A joint replacement prosthesis comprising:

• a first bearing element including a first bearing surface and a first medial/lateral centerline, the first bearing surface having a first radius of curvature and a first center of curvature, the first center of curvature located proximate the first medial/lateral centerline;
• a second bearing element spaced apart from the first bearing element and movable relative to the first bearing element, the second bearing element including a second bearing surface and a second medial/lateral centerline, the second bearing surface having a second radius of curvature and a second center of curvature, the second center of curvature located proximate the second medial/lateral centerline;
• a linking element configured to operatively connect the first bearing element and the second bearing element and permit relative motion therebetween;
• a tray configured to support the first bearing element and the second bearing element;
• and
• a bridge element that, when attached to the tray, extends across the tray, between the first and second bearing elements, and passes over the linking element transversely relative to a longitudinal axis of the linking element.

A knee prosthesis comprising:

• a femoral component;
• a tibial component including a tibial tray;
• a first bearing element configured to articulate with the tibial tray, the first bearing element including a first bearing surface and a first anterior/posterior centerline, the first bearing surface having a first radius of curvature and a first center of curvature, the first center of curvature located anterior of the first anterior/posterior centerline;
• a second bearing element spaced apart from the first bearing element, movable relative to the first bearing element, and configured to articulate with the tibial tray, the second bearing element including a second bearing surface and a second anterior/posterior centerline, the second bearing surface having a second radius of curvature and a second center of curvature, the second center of curvature located anterior of the second anterior/posterior centerline;
• a linking element configured to operatively connect the first bearing element and the second bearing element and permit relative motion therebetween;
• a bridge element that, when attached to the tibial tray, extends across the tibial tray, between the first and second bearing elements, and passes over the linking element transversely relative to a longitudinal axis of the linking element;
• and
• an artificial ligament configured to extend, in an implanted state, from the femoral component, between the first and second bearing elements, and to the bridge element.