Patent ID: 8636777
Filing Date: 2014-01-28
Classification: A61B

Abstract:
1. A polyaxial bone screw assembly method comprising: (a) compressing and inserting an open ring-like retainer structure into a cavity being disposed on an interior of a head, the retainer structure having a discontinuous inner surface with a discontinuous first helically wound advancement structure thereon; (b) inserting a capture structure of a bone screw shank through a shank receiving opening being disposed on a lower portion of the head and into the cavity thereof, the capture structure being integral with an elongate threaded shank body and having an outer surface with a second helically wound advancement structure thereon and a top convex surface, the head having an outward opening channel being disposed on a upper portion adapted to receive a rod within the channel, the cavity being disposed between and communicating with both the channel and the shank receiving opening; (c) attaching the capture structure to the open retainer structure within the cavity by mating the first and second helically wound advancement structures; and (d) inserting the rod within the channel sized and shaped to receive the rod such that the top convex surface of the shank engages the rod.