Patent ID: 8734497
Filing Date: 2014-05-27
Classification: A61B

Abstract:
1. An anchoring pedicle screw assembly for fixing an implant to a vertebra comprising: an implant mounting screw having a threaded bore; an anchor screw configured to engage the threaded bore for relative rotation; a nose piece configured to engage the anchor screw; and an expandable anchor disposed between the implant mounting screw and the nose piece such that rotation of the anchor screw relative to the implant mounting screw causes expansion of the expandable anchor, wherein either: (1) the anchor screw includes a threaded body that extends along the entire axial length of the anchor screw; (2) the expandable anchor cooperates with the anchor screw to define a cavity that contains a filler material; (3) the expandable anchor is formed from a polymer and includes at least one ridge formed from a polymer having a durometer that is different from the durometer of the rest of the expandable anchor; or (4) the nose piece includes a ported sleeve configured to contain a filler material and having at least one vent, and the expandable anchor is disposed over the ported sleeve such that, as the anchor screw is advanced toward the nose piece, the filler material is exhausted through the at least one vent causing the expandable anchor to expand radially outward away from the anchor screw.