CLOSURE FOR OPEN-HEADED MEDICAL IMPLANT
A closure for an open headed medical implant, such as a bone screw. The closure having a cylindrical body having an axis of rotation and also having a radially outer surface with a thread or other guide and advancement structure thereon. The body having a plurality of apertures that open onto a top surface of the body and that are parallel to but spaced from the axis of rotation. The closure also has a break-off head centrally attached by a neck to the top surface of the body.
1 - 10 . (canceled)
11 . A closure for operably closing a top portion of a rod receiving channel between two arms of a bone anchor, the closure comprising:
a) a body with a radially outer surface that is threaded, a top surface, a bottom surface, a central bore that is threaded extending between the top surface and the bottom surface about a central axis, and a drive structure located on the top surface that is positioned between the central axis and the outer surface; and
b) a set screw with a radially outer surface that is continuously threaded from near a top surface to near a bottom surface thereof, the bottom surface configured to engage and lock a rod.
12 . The closure according to claim 11 , wherein the set screw and the body of the closure are positioned between a pair of top surfaces of the two arms of the bone anchor, so as to provide a comparatively low profile with respect to the pair of top surfaces of the bone anchor arms.
13 . The closure according to claim 11 , wherein the drive structure is a bore opening onto the top surface and being spaced from the central axis and the outer surface.
14 . The closure according to claim 13 , wherein the closure comprises a plurality of drive structure bores, each being spaced from the central bore and outer surface.
15 . The closure according to claim 11 , wherein the closure comprises a plurality of drive structures, each being spaced from the central bore and outer surface.
16 . The closure according to claim 11 , wherein the set screw bottom surface is flat.
17 . The closure according to claim 11 , wherein the set screw and the body of the closure do not extend above the bone anchor arms.