Transverse connector

Abstract

A transverse connector for coupling between first and second vertebral anchors of a spinal stabilization system. The transverse connector includes a first coupling assembly proximate a first end, a second coupling assembly proximate a second end, a first fastener having external threading configured to threadably engage an internal threaded portion of a housing of the first vertebral anchor, and a second fastener having external threading configured to threadably engage an internal threaded portion of a housing of the second vertebral anchor. Each of the first and second fasteners includes a spherical upper surface, such as a spherically concave upper surface. A spherical surface of each of the first and second coupling assemblies mates with the spherical upper surface of the respective fastener to provide multi-axial rotation of the transverse connector relative to the housings to permit a desired orientation of the transverse connector.

What is claimed is: 
     
         1 . A transverse connector for coupling between first and second vertebral anchors of a spinal stabilization system, the transverse connector comprising:
 a first coupling assembly proximate a first end of the transverse connector, the first coupling assembly including:
 a first coupling housing having an upper surface, a lower surface, and an elongated opening extending from the upper surface to the lower surface of the first coupling housing; 
 a first fastener positionable through the elongated opening of the first coupling housing, the first fastener including a first threaded portion configured to threadably engage an internal threaded portion of a housing of the first vertebral anchor; and 
 a third fastener including a threaded portion configured to threadably engage a second threaded portion of the first fastener; 
   a second coupling assembly proximate a second end of the transverse connector, the second coupling assembly including:
 a second coupling housing having an upper surface, a lower surface, and an elongated opening extending from the upper surface to the lower surface of the second coupling housing; 
 a second fastener positionable through the elongated opening of the second coupling housing, the second fastener including a first threaded portion configured to threadably engage an internal threaded portion of a housing of the second vertebral anchor; and 
 a fourth fastener including a threaded portion configured to threadably engage a second threaded portion of the second fastener; 
   wherein the first coupling housing of the transverse connector is positionable at a plurality of angular positions relative to a longitudinal axis of the housing of the first vertebral anchor; and   wherein the second coupling housing of the transverse connector is positionable at a plurality of angular positions relative to a longitudinal axis of the housing of the second vertebral anchor.   
     
     
         2 . The transverse connector of  claim 1 , wherein the first fastener is configured to secure a first elongate member in the housing of the first vertebral anchor and the second fastener is configured to secure a second elongate member in the housing of the second vertebral anchor. 
     
     
         3 . The transverse connector of  claim 2 , wherein a lower surface of the first fastener is configured to press against the first elongate member in the housing of the first vertebral anchor, and a lower surface of the second fastener is configured to press against the second elongate member in the housing of the second vertebral anchor. 
     
     
         4 . The transverse connector of  claim 1 , wherein the first fastener and the third fastener are rotatable about the longitudinal axis of the housing of the first vertebral anchor. 
     
     
         5 . The transverse connector of  claim 4 , wherein the second fastener and the fourth fastener are rotatable about the longitudinal axis of the housing of the second vertebral anchor. 
     
     
         6 . The transverse connector of  claim 1 , wherein:
 the first fastener includes a driver socket extending into the first fastener from an upper surface of the first fastener to accommodate a driver instrument for threadably engaging the first fastener in the internal threaded portion of the housing of the first vertebral anchor, and   the second fastener includes a driver socket extending into the second fastener from an upper surface of the second fastener to accommodate a driver instrument for threadably engaging the second fastener in the internal threaded portion of the housing of the second vertebral anchor.   
     
     
         7 . The transverse connector of  claim 6 , wherein:
 the third fastener extends above the upper surface of the first fastener when threadably engaged to the second threaded portion of the first fastener, and   the fourth fastener extends above the upper surface of the second fastener when threadably engaged to the second threaded portion of the second fastener.   
     
     
         8 . The transverse connector of  claim 7 , wherein:
 the third fastener includes a head portion having a spherical lower surface, and the threaded portion of the third fastener extends from the spherical lower surface of the third fastener; and   the fourth fastener includes a head portion having a spherical lower surface, and the threaded portion of the fourth fastener extends from the spherical lower surface of the fourth fastener.   
     
     
         9 . The transverse connector of  claim 8 , wherein:
 the third fastener includes a driver socket extending into the head portion of the third fastener from an upper surface of the head portion of the third fastener to accommodate a driver instrument for threadably engaging the third fastener with the first fastener; and   the fourth fastener includes a driver socket extending into the head portion of the fourth fastener from an upper surface of the head portion of the fourth fastener to accommodate a driver instrument for threadably engaging the fourth fastener with the second fastener.   
     
     
         10 . The transverse connector of  claim 8 , wherein:
 the spherical lower surface of the third fastener is matingly engageable with a spherical surface of the first coupling assembly; and   the spherical lower surface of the fourth fastener is matingly engageable with a spherical surface of the second coupling assembly.   
     
     
         11 . The transverse connector of  claim 8 , wherein:
 the spherical lower surface of the third fastener is a convex spherical surface; and   the spherical lower surface of the fourth fastener is a convex spherical surface.   
     
     
         12 . The transverse connector of  claim 1 , wherein:
 the second threaded portion of the first fastener is an internal threaded portion; and   the second threaded portion of the second fastener is an internal threaded portion.   
     
     
         13 . The transverse connector of  claim 1 , wherein:
 an upper portion of the first fastener including the second threaded portion has an outer diameter and a lower portion of the first fastener including the first threaded portion has an outer diameter different than the outer diameter of the upper portion of the first fastener; and   an upper portion of the second fastener including the second threaded portion has an outer diameter and a lower portion of the second fastener including the first threaded portion has an outer diameter different than the outer diameter of the upper portion of the second fastener.   
     
     
         14 . The transverse connector of  claim 1 , wherein:
 the first fastener is translatable in the elongated opening of the first coupling housing in a direction generally transverse to a rotational axis of the first fastener; and   the second fastener is translatable in the elongated opening of the second coupling housing in a direction generally transverse to a rotational axis of the second fastener.