Dynamic stabilization system

Abstract

A spinal stabilization system including an insert positionable in the channel of the housing of a vertebral anchor, and an associated support construct including a spacer and at least one cord extending through the insert. In some instances the construct includes first and second cords extending through first and second bores of the insert. A clamping member clamps the cord(s) in the insert. In some instances the clamping member includes first and second tabs movable in channels in first and second flanges of the insert.

1 . A spinal stabilization system comprising:
 an insert positionable in a channel of a housing of a vertebral anchor, the insert having a first end positionable on a first side of the housing of the vertebral anchor and a second end positionable on a second side of the housing of the vertebral anchor; and   a support construct including a spacer and first and second cords extendable through the spacer, the first and second cords positionable through the insert.   
     
     
         2 . The spinal stabilization system of  claim 1 , wherein the insert includes a first bore for receiving the first cord therethrough and a second bore for receiving the second cord therethrough. 
     
     
         3 . The spinal stabilization system of  claim 1 , further comprising:
 a vertebral anchor including a housing defining a channel; and   a fastener configured to rotatably engage the housing of the vertebral anchor, wherein rotational engagement of the fastener with the housing causes the fastener clamp both the first and second cords in the insert.   
     
     
         4 . The spinal stabilization system of  claim 3 , wherein the fastener directly contacts each of the first and second cords to exert a clamping force directly on the first and second cords. 
     
     
         5 . The spinal stabilization system of  claim 3 , wherein the fastener includes a threaded portion and a protuberance extending from the threaded portion, wherein the protuberance is extendable into an opening of the insert to contact each of the first and second cords. 
     
     
         6 . The spinal stabilization system of  claim 5 , wherein the opening intersects with each of the first and second bores. 
     
     
         7 . The spinal stabilization system of  claim 3 , wherein rotational engagement of the fastener with the housing causes the fastener to clamp both the first and second cords in the insert and secure the insert in the housing of the vertebral anchor. 
     
     
         8 . The spinal stabilization system of  claim 7 , wherein the first bore extends parallel to and offset from the second bore, and the opening extends perpendicular to and between the first and second bores. 
     
     
         9 . The spinal stabilization system of  claim 3 , wherein the vertebral anchor includes a threaded shaft extending from the housing, wherein the threaded shaft has a lumen extending therethrough for advancement over a K-wire. 
     
     
         10 . The spinal stabilization system of  claim 9 , wherein the opening extends entirely through the insert such that the insert is advanceable over the K-wire into the housing of the vertebral anchor with the K-wire positionable between the first and second cords. 
     
     
         11 . A spinal stabilization system comprising:
 an insert securable to a housing of a vertebral anchor, the insert having a first flange positionable on a first side of the housing of the vertebral anchor, a second flange positionable on a second side of the housing of the vertebral anchor, and a medial portion between the first and second flanges positionable in a channel of the housing of the vertebral anchor; and   a support construct including a spacer and a cord extendable through the spacer, the cord positionable through a bore of the insert;   a clamping member movable relative to the medial portion to clamp the cord in the bore of the insert.   
     
     
         12 . The spinal stabilization system of  claim 11 , wherein the clamping member includes a concave engagement surface configured to press against a portion of the periphery of the cord, preferably 30 degrees or more of the periphery of the cord. 
     
     
         13 . The spinal stabilization system of  claim 11 , wherein the clamping member includes a first tab movable in a channel in the first flange and a second tab movable in a channel in the second flange. 
     
     
         14 . The spinal stabilization system of  claim 13 , wherein the clamping member is configured to be held in a loading position prior to clamping onto the cord. 
     
     
         15 . The spinal stabilization system of  claim 13 , wherein each of the channels has an upper portion having a first width and a lower portion having a second width, the first width being less than the width of the first and second tabs to form an interference fit with the first and second tabs, and the second width being greater than the width of the first and second tabs. 
     
     
         16 . The spinal stabilization system of  claim 13 , wherein each of the channels has an upper portion having a first width and a lower portion having a second width, wherein the first width and the second width are equal. 
     
     
         17 . The spinal stabilization system of  claim 13 , wherein each of the channels has an upper portion having a protuberance extending radially towards the bore, wherein each of the first tab and the second tab have a void disposed therein to matingly receive the respective protuberance.