Cup without thread for cementless implantation and associated acetabular cup prosthesis

摘要

The prosthesis, e.g. for a replacement hip implant,consists of a cup (1) with a hemispherical outer surface (1a) with three equally-spaced locating spikes (4). The cup is fitted in place with the aid of a smooth-surfaced guide rod (6) which projects through an aperture (5) in the wall of the cup and is joined to it by threaded surfaces round the aperture and the proximal end of the rod. The guide rod is inclined relative to the cup's axle at an angle of between 20 and 40 degrees and preferably 30 degrees, and the aperture (5) can be closed by a threaded stopper when the guide rod is not fitted to it. The cup is designed to receive an insert of a plastic material, e.g. polyethylene.