Patent attributes
A bone screw assembly including a coupling member with a lower surface and a channel formed by two arms extending from a base portion. The coupling member has a hole extending from the base portion of the channel to its lower surface. The assembly further includes a spacer having a top surface adjacent the base portion of the channel and a bottom surface generally opposite the top surface within the hole of the coupling member, and includes a hollow retaining ring within the hole of the coupling member, the retaining ring comprising an inner surface, an outer surface, a top surface spaced from the bottom surface of the spacer, and a slot extending from the inner surface of the ring to the outer surface of the ring. The assembly includes a bone screw having a head portion with an outer surface adjacent to the inner surface of the retaining ring.