Low profile connectors

Abstract

Devices and methods for coupling first and second adjacent vertebrae. The device includes a first coupling element and a second coupling element. The first coupling element has a first body portion for receiving a first bone fastener and an elongate rod portion extending transversely from the first body portion. The second coupling element has a second body portion for receiving a second bone fastener and an extension portion extending transversely from the second body portion. The extension portion defines a recess sized and configured to receive the rod portion of the first coupling element. When unlocked, the rod portion is moveable in the recess to allow for rotational and translational movement of the first and second coupling elements. When locked, the relative position of the first and second coupling elements is fixed.

What is claimed is: 
     
         1 . A coupling device for securing first and second vertebrae, the device comprising:
 a first coupling element having a first body portion with an opening extending longitudinally through the first body portion;   a first locking assembly comprising a rotatable locking member, a clamp portion, and a ring portion, wherein the first locking assembly is configured to be received in the opening of the first body portion, wherein the first coupling element is configured to receive a head of a first bone fastener, and wherein the first coupling element comprises an elongate rod portion extending transversely from the first body portion; and   a second coupling element having a second body portion for receiving a second bone fastener and an extension portion extending transversely from the second body portion, the extension portion defining a recess sized and configured to receive the rod portion of the first coupling element,   wherein the locking member is configured to be rotated to a locked position forcing the ring portion and clamp portion downward to secure the first bone fastener.   
     
     
         2 . The device of  claim 1 , wherein the rotational and translational positions of the first and second coupling elements are locked simultaneously. 
     
     
         3 . The device of  claim 1 , wherein the extension portion of the second coupling element includes a locking element, and when locked, the locking element contacts the rod portion of the first coupling element. 
     
     
         4 . The device of  claim 3 , wherein the locking element is in the form of a set screw configured to apply a downward force on the rod portion of the first coupling element when locked. 
     
     
         5 . The device of  claim 1 , wherein the first and second coupling elements have first and second locking assemblies, respectively, configured to secure the first and second fasteners. 
     
     
         6 . The device of  claim 5 , wherein the first and second locking assemblies each comprise a locking member, a clamp portion, and a ring portion configured to at least partially surround a portion of the locking member and the clamp portion. 
     
     
         7 . The device of  claim 6 , wherein when the locking member is rotated to the locked position, the locking member forces the ring portion and clamp portion downward to secure the respective first or second bone fastener. 
     
     
         8 . The device of  claim 6 , wherein the clamp portion includes at least one slit extending therethrough to allow the clamp portion to be compressed around a head of the respective first or second bone fastener when the respective first or second locking assembly is locked. 
     
     
         9 . The device of  claim 8 , wherein the at least one slit has an angled portion, a longitudinal portion extending along a longitudinal axis of the first or second body portion, and a perpendicular portion extending substantially transverse to the longitudinal axis which connects the angled portion to the longitudinal portion. 
     
     
         10 . A coupling assembly for securing first and second vertebrae, the assembly comprising:
 a first bone fastener having a head and a shaft extending therefrom, the shaft configured to engage the first vertebra;   a second bone fastener having a head and a shaft extending therefrom, the shaft configured to engage the second vertebra;   a first coupling element having a first body portion housing a first locking assembly and an elongate rod portion extending transversely from the first body portion, the first locking assembly comprising a first rotatable locking member, a first clamp portion, and a first ring portion configured to at least partially surround a portion of the first locking member and the first clamp portion, and the head of the first bone fastener is received in the first clamp portion; and   a second coupling element having a second body portion housing a second locking assembly and an extension portion extending transversely from the second body portion, the extension portion defining a recess for receiving the rod portion of the first coupling element, the second locking assembly comprising a second rotatable locking member, a second clamp portion, and a second ring portion configured to at least partially surround a portion of the second locking member and the second clamp portion, and the head of the second bone fastener is received in the second clamp portion;   wherein the first locking member is configured to be rotated to a locked position forcing the first ring portion and first clamp portion downward to secure the first bone fastener.   
     
     
         11 . The assembly of  claim 10 , wherein the rotational and translational positions of the first and second coupling elements are locked simultaneously. 
     
     
         12 . The assembly of  claim 10 , wherein the extension portion of the second coupling element includes a locking element. 
     
     
         13 . The assembly of  claim 12 , wherein when locked, the locking element contacts the rod portion of the first coupling element. 
     
     
         14 . The assembly of  claim 12 , wherein the locking element is in the form of a set screw configured to apply a downward force on the rod portion of the first coupling element when locked. 
     
     
         15 . The assembly of  claim 10 , wherein the clamp portion of the first or second locking assembly includes at least one slit extending therethrough to allow the clamp portion to compress around the head of the respective first or second bone fastener when the respective first or second locking assembly is locked. 
     
     
         16 . A method for affixing a coupling device to adjacent vertebrae, the method comprising:
 securing a first bone fastener to a pedicle of a first vertebra;   securing a second bone fastener to a pedicle of a second vertebra;   attaching a coupling device to the first and second bone fasteners, the coupling device comprising:
 a first coupling element having a body portion for receiving the first bone fastener and an elongate rod portion; and 
 a second coupling element having a body portion for receiving the second bone fastener and an extension portion, the extension portion defining a recess sized and configured to receive the rod portion of the first coupling element, 
 wherein a first locking member is configured to be rotated to a locked position forcing a first ring portion and a first clamp portion of the first locking member downward to secure the first bone fastener 
   moving the rod portion relative to the extension portion to allow for rotational and translational movement of the first and second coupling elements; and   locking the position of the rod portion in the recess to fix the first coupling element relative to the second coupling element.   
     
     
         17 . The method of  claim 16 , wherein the position of the first and second coupling elements is locked by rotating a locking member, and the locking member includes a set screw extending through the extension portion that contacts the rod portion when locked. 
     
     
         18 . The method of  claim 16 , wherein when securing the first and second bone fasteners in the first and second vertebrae, a head of each of the first and second bone fasteners remains proud above the first and second vertebrae. 
     
     
         19 . The method of  claim 16 , wherein the first and second coupling elements have first and second locking assemblies, respectively, the first and second locking assemblies each comprise a rotatable locking member, a clamp portion, and a ring portion configured to at least partially surround a portion of the locking member and the clamp portion. 
     
     
         20 . The method of  claim 19  further comprising rotating the locking member to force the ring portion and clamp portion downward to secure the respective first or second bone fastener.