A knee prosthesis is provided having a femoral component (1) with a pair of laterally spaced condylar formations (2) at one end, and a tibial component (3) having a transverse platform (4) supporting a shock absorbing bumper (5) interposed between the platform and condylar formations with the tibial component supporting a ball (6) of a ball and socket joint. The socket (8) is provided in a generally cylindrical bearing (9) having an axis extending generally parallel to a longitudinal axis of the femoral component. The bearing is held captive in a recess that is between the two laterally spaced condylar formations and is formed in the region of said end of the femoral component. The axis of the bearing is preferably inclined laterally at an angle of about 5° relative to the axis of the femoral component so that it is able to line up with a mechanical axis of a lower limb.
