Patent ID: 7662182

Claim:
For an intervertebral disc replacement device having a flange and at least one bone screw hole for receipt therethrough of at least one bone screw and at least one mounting hole, a retaining device for said at least one bone screw, comprising: a threaded attachment member for threaded engagement with said at least one mounting hole in said flange of said intervertebral disc replacement device; and a head flange defined by an outer perimeter, said head flange extending from said threaded attachment member, wherein said head flange is in part abuttingly received against a side of said flange of said intervertebral disc replacement device and said outer perimeter is partially received over a portion of said at least one bone screw to prevent said at least one bone screw from backing out of said at least one bone screw hole when said retaining device is fully engaged with said intervertebral disc replacement device, wherein said head flange includes a solid portion and at least one stress relief area wholly contained within the confines of and not extending through said outer perimeter so that the at least one stress relief area is bounded on all lateral sides by the solid portion, the at least one stress relief located on said head flange at a point other than a central point of said head flange and providing for said head flange to be at least somewhat flexible in a substantially axial direction of said threaded attachment member.