Patent ID: 7625409

Claim:
A fixed-bearing ankle prosthesis, comprising: a tibial component for attachment to a tibia, wherein the tibial component has first and second surfaces; and a talar component for attachment to a talus, wherein the talar component has first and second surfaces and medial and lateral edges; wherein: at least a portion of the first surface of the tibial component is configured to be disposed adjacent the tibia; at least a portion of the first surface of the talar component is configured to be disposed adjacent the talus; at least a portion of the second surface of the tibial component and at least a portion of the second surface of the talar component contact one another directly to form an articulation interface between the tibial component and the talar component; the articulation interface includes a bicondylar geometry such that the second surface of the tibial component defines a medial condylar facet and a lateral condylar facet and the second surface of the talar component comprises a medial condyle and a lateral condyle; the medial and lateral condylar facets of the tibial component have concave circular arc cross-sections extending in a medial-lateral plane; the medial and condyle of the talar component has a first single radius in the medial-lateral plane that defines a convex circular arc cross-section continuously extending, in the medial-lateral plane, from the medial edge of the talar component to a concave central portion of the talar component second surface separating the medial and lateral condyles; the lateral condyle of the talar component has a second single radius in the medial-lateral plane that defines a convex circular arc cross-section continuously extending, in the medial-lateral plane, from the lateral edge of the talar component to the concave central portion of the talar component second surface; the concave circular arc cross-section of the medial condylar facet of the tibial component has a radius in the medial-lateral plane larger than the first radius; and the concave circular arc cross-section of the lateral condylar facet of the tibial component has a radius in the medial-lateral plane larger than the second radius.