Ankle prosthesis
AssigneesUniversity of Iowa Research Foundation, Jonathan T. Deland, Albert H. Burstein
InventorsCharles L. Saltzman, Albert H. Burstein, Jonathan T. Deland
Life of this patent
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Abstract
A fixed-bearing ankle prosthesis may include tibial and talar components whose articulating surfaces directly contact one another. The tibial component defines medial and lateral concave condylar facets separated by a convex central portion. The talar component includes medial and lateral convex condyles separated by a concave central portion. The condyles each have a single radius of curvature in a medial-lateral plane such that each condyle has a circular-arc cross-section continuously extending from the respective medial or lateral edge of the talar component to the concave central portion. The medial-lateral radii of the condyles are smaller than corresponding radii of the condylar facets.
Claims11
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.
A fixed-bearing ankle prosthesis comprising a tibial component and a talar component, wherein:
- the tibial component comprises a tibial attachment surface and a tibial articulating surface;
- the talar component comprises a medial edge, a lateral edge, a talar attachment surface and a talar articulating surface, the talar articulating surface directly contacting the tibial articulating surface;
- the tibial articulating surface comprises a medial concave condylar facet and a lateral concave condylar facet, each condylar facet having a radius of curvature in a medial-lateral plane that defines a respective circle arc, the facets separated from one another by a convex central portion;
- the talar articulating surface comprises a medial convex condyle that underlies the medial condylar facet, and a lateral convex condyle that underlies the lateral condylar facet, the condyles separated from one another by a concave central portion that underlies the tibial convex central portion;
- the medial condyle of the talar component has a first single radius of curvature 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 the concave central portion of the talar articulating surface;
- the lateral condyle of the talar component has a second single radius of curvature 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 medial condyle radius of curvature is smaller than the medial condylar facet radius of curvature;
- and
- the lateral condyle radius of curvature is smaller than the lateral condylar facet radius of curvature.
Dependencies are inferred from the claim text.