Abstract: A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate head and a generally hollow coupling element. The coupling element includes an interior axial passage having an interior surface which is inwardly curvate at the lower portion thereof such that it comprises a socket for polyaxially retaining the curvate head of the screw. The coupling element further includes a pair of vertically oriented opposing channels extending down from the top of the coupling element, which define therebetween a rod receiving locus. The channel further divides the walls of the upper portion into a pair of upwardly extending members, each including an exterior threading disposed on the upper most portion for receiving a locking nut. During implantation of the assembly, the locking nut seats against the top of the rod, which in turn seats on the top of the screw head.

Abstract: A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate head and a coupling element. The coupling element has a tapered lower portion including a slotted interior chamber in which the curvate head is initially polyaxially disposed; a recess formed in its side for receiving the rod of the implant apparatus; and an exterior threading disposed on its upper portion for receving thereon a top locking nut. A locking ring is disposed about the exterior of the lower portion of the coupling element, and provides an inward force on the outwardly tapered portion upon downward translation thereof, thereby causing the interior chamber to crush lock the screw head therein, thus eliminating the polyaxial nature of the screw-element coupling. In addition, a hollow cylindrical rod securing sleeve fits over the coupling element and locks the rod to the coupling element.