A clamp for linking parts of a wrist, carpal or ankle prosthesis together is described. The clamp provides orthogonal linkage of two portions of the prosthesis such that one fastener will lock them in place. The clamp (4) has first and second openings or apertures (72 and 74), a deflectable member (70) and a locking screw fastener thread (76) which receives a screw or lug. When the apertures are filled with a bar or rod, tightening the lug clamps the rod in the first aperture (72) and depresses the deflectable member (70), which subsequently clamps a rod in the second aperture (72). The assembly is suitable for linking a radius bone and an ulna bone of an arm.
