Patent ID: 8012217

Claim:
An implant comprising: a head having an upper surface, an anterior surface, a posterior surface, a lateral surface, and a lower surface; the anterior surface, the lateral surface, and the lower surface are each flat, approximately perpendicular, and intersect each other; the anterior surface and the posterior surface are approximately parallel to each other, wherein the upper surface has a general shape of at least a portion of a superior articular surface of a talus and at least a portion of a medial articular surfaces of a talus, wherein the upper surface includes a convex first portion having a generally toroidal shape, a second portion having a general toroidal saddle shape, and a third portion having a general shape of a portion of a surface of a right circular cone, wherein the first portion is tangent on its lateral edge to the second portion and the first portion is tangent on its medial edge to the third portion; and a stem having a cylindrical portion and a truncated conical portion, the cylindrical portion affixed to and extending in a direction away from the lower surface of the head and the truncated conical portion affixed to and extending in a direction away from a lower end of the cylindrical portion.