In one embodiment a method of implanting a prosthetic includes implanting a first member including a concave articulation surface portion defined by a first radius of curvature in a first bone, implanting in a second bone a second member including a first convex articulation surface portion defined by a second radius of curvature and a second convex articulation surface defined by a third radius of curvature, wherein the second convex articulation surface is defined by the lemon portion of a spindle torus and each of the second radius of curvature and the third radius of curvature has a length that is different from the length of the first radius of curvature by less than 0.05 millimeters and wherein the origin of the second radius of curvature is not coincident with the origin of the third radius of curvature, and bringing the first member into slidable contact with the second member.