A clamp for a linkage for linking first and second bone fasteners of a prosthesis assembly, the clamp comprising a clamp body having a first receiving portion for receiving a first component of a prosthesis assembly and a second receiving portion for receiving a second component of the prosthesis assembly, the clamp having a deflectable member which deflects from a first position to a second position when one of the first and second components is introduced to its corresponding receiving portion, wherein when the deflectable member is in the second position and the other one of the first and second components is received by the clamp, the deflectable member is engageable with said other one of the first and second components.