A prosthesis for implantation in an animal or human subject, said prosthesis comprising a first component (6) for attaching to a radius bone in use and a second component (7) for attaching to an ulna bone in use, the prosthesis further comprising a linkage (8)1 for linking the first and second components substantially rigidly with respect to one another in use. Preferably the prosthesis is configured to allow the linkage to move relative to the first and/or second components and be retained substantially rigidly at a selected position in normal use, such that the first and second components can be retained substantially rigidly relative to one another in normal use.
