Hip or knee prosthesis ball and socket joint - has ball end attached to stem with teeth along edges of ribs

摘要

The ball and socket joint for a hip or knee prosthesis uses a ball portion consisting of a ball end (3) mounted on a spindle (2) which is forced into a cavity (A) in the bone (K). These are in one piece, the spindle portion being cross shaped in section, the arms (6, 7) having teeth (8) from end to end, on their outer edges. The bottom (9) of the spindle is tapered, and carries self cutting teeth (10). The ball end is attached by a neck (4) to a flange (5), these parts being arranged along an axis which is at an angle of about 45 deg. to the axis (S) of the spindle.