Patent ID: 8579949

Claim:
A multi-axial screw assembly, comprising: a receiver comprising a channel for receiving a rod and an aperture extending from a bottom portion of the receiver; a base member comprising an aperture extending through the base member and an opening on a bottom portion of the base member, the base member configured to couple to the receiver such that the aperture of the receiver is generally aligned with the aperture of the base member, the base member being rotatable relative to the receiver, the base member having an inner wall extending partially around the aperture of the base member; a crown received in the receiver configured to mate to the base member, the crown having a projection configured to extend into the opening of the base member, the projection comprising an abutting surface offset from an undersurface of the crown such that the abutting surface is proud relative to the undersurface; and a bone screw located between the base member and the crown, the bone screw configured to be provisionally fixed within the receiver by a force between the abutting surface of the projection and the inner wall of the base member, wherein the projection is configured to flex outwardly, narrowing the offset, until a portion of the bone screw is in flush contact with the undersurface when the bone screw is positioned between the base member and the crown.