Patent ID: 7316715
Filing Date: 2008-01-08
Classification: A61B,A61F

Abstract:
1. A system for rigidly connecting a bone screw to an acetabular cup shell, the system comprising: a part-spherical acetabular cup shell having an inner surface and an external bone-facing surface for contacting the natural acetabulum with at least one aperture therethrough said aperture having a non-circular profile side wall formed by a part-spherical radially inwardly facing surface extending from an inner surface of the shell to the external bone-facing surface of the shell; a split-ring having a non-circular external profile mounted in said aperture having a part-spherical outer surface for engaging said aperture side walls and a cylindrical internal bore and including a slot in a wall of said split-ring extending between said internal bore and said part-spherical outer surface of said split-ring; a bone screw having a head portion with a completely cylindrical outer surface mounted within the internal bore of the split-ring; and means for moving said wall of said split-ring with respect to said slot therein in a manner to simultaneously engage both the head portion of the bone screw and the side wall of the aperture in the shell by the rotational engagement of the non-circular profiles of the aperture and the split-ring.