Spine fixation system
AssigneeAdvanced Spine Fixation Systems, Inc.
InventorRobert S. Howland
Life of this patent
Estimating the term…
Abstract
An implantable spinal fixation system includes a cancellous bone screw, such as a pedicle screw, carrying an improved saddle assembly, secured in place by a nut and which includes a simple and effective locking mechanism including a plurality of fingers which contacts each of the upper half saddle and the nut to prevent rotation of the latter relative to the remained of the assembly. The implant system also includes rods, firmly gripped by the saddle assembly and sublaminar wires in which the rod/wire interface is protected by a wire protector.
Claims16
A cancellous bone screw and clamp assembly for use in a spinal support system for support and fixation of at least portions of the spinal column comprising:
- a screw clamp shaft member having a threaded end portion adapted to be screwed into a preselected location of the spinal column or sacrum and a threaded end opposite the threaded end portion,
- a saddle assembly mounted on the threaded end of said shaft member and including mating upper and lower half saddles which form at least one pair of spaced rod receiving apertures,
- said apertures being in spaced relation and each including serrated opposed faces to receive a rod serrated along its length to effect purchase securely on the rod assembled thereto and to prevent rotation of the rod relative to said saddle assembly,
- nut means received on the threaded end of said shaft assembly to secure the mating half saddles together such that the serrated rod positioned in the rod receiving apertures are gripped by the mating half saddles along a predetermined length of the serrated surface of said rod to secure said rod firmly to said screw clamp assembly in a predetermined orientation with respect to the spinal column or sacrum,
- lock means to prevent said nut means from unthreading, and
- said lock means being located between said nut means and said upper half saddle and including a plurality of spaced finger means some of which engage said nut means and others of which engage said upper half saddle to prevent rotation of said nut means relative to the threaded end of said shaft assembly.
In a cancellous bone screw and locking assembly including a bone screw member having a threaded portion for insertion into a bone and a threaded end portion carrying support means to be fixedly attached to said bone screw by a nut threaded on the threaded end of said bone screw, an improved locking system comprising:
- locking means received on the threaded end of said bone screw member between said nut and said support means,
- said locking means including a plurality of spaced fingers,
- means in said support means for receiving one of the fingers of said locking means, and
- the other of said locking means contacting said nut to prevent rotation thereof relative to said bone screw member.
A spinal support and fixation system for internal fixation of the posterior spine comprising:
- bone screw and clamp assemblies adapted to be mounted at selected portions of the spine,
- rod means having portions adapted to be received in said clamp assemblies,
- nut means for securing said clamp assemblies to said bone screw,
- locking means for locking said nut means to said clamp assemblies and including a plurality of fingers,
- said locking means being located between said nut means and said clamping assemblies,
- means in said clamp assemblies for receiving one of the fingers of said locking means, and
- the other of said locking means contacting said nut to prevent rotation thereof relative to said bone screw member.
A spinal support and fixation system for internal fixation of the posterior spine comprising:
- bone screw and clamp assemblies adapted to be mounted at selected portions of the spine,
- rod means having portions adapted to be received in said clamp assemblies of said bone screw and clamp assembly,
- said rod means including a portion which passes around the cranial border of the spinous process,
- sublaminar wiring for securing said rod means to said spine, and
- wire protector means carried by said rod means and positioned between said rod means and said sublaminar wiring.
Dependencies are inferred from the claim text.