Vertebral joint implants and delivery tools

Abstract

A spinal joint distraction system for treating a facet joint including articular surfaces having a contour is disclosed and may include a delivery device including a generally tubular structure adapted to engage a facet joint, an implant adapted to be delivered through the delivery device and into the facet joint, the implant comprising two members arranged in opposed position, and an implant distractor comprising a generally elongate member adapted to advance between the two members of the implant causing separation of the members and distraction of the facet joint, wherein the implant is adapted to conform to the shape of the implant distractor and/or the articular surfaces of the facet upon being delivered to the facet joint. Several embodiments of a system, several embodiments of an implant, and several methods are disclosed including a method for interbody fusion.

What is claimed is: 
     
         1 . A system for distracting a facet joint of a spine via a posterior approach to the spine, the system comprising:
 a chisel comprising a shaft, a distal tip and a proximal end;   a delivery device comprising a receiving assembly at a proximal end, anchoring forks at a distal end, and a tubular shaft between the receiving assembly and the anchoring forks, wherein the delivery device tubular shaft is sized to slide over the shaft of the chisel;   a decorticator comprising a tubular shaft, an abrasive distal end and handle at a proximal end, wherein the decorticator tubular shaft is sized to slide over and rotationally around the delivery device tubular shaft;   a hammer for tapping the proximal ends of the chisel and the delivery device to deliver distal tip of the chisel and the forks of the delivery device into the facet joint;   a driver assembly comprising an implant shaft and implant holding arms; and   an implant removably mounted on the implant arms of the driver assembly for distracting the facet joint.   
     
     
         2 . A system as in  claim 1 , wherein the distal tip of the chisel and the forks of the delivery device have a matching V-shape. 
     
     
         3 . A system as in  claim 1 , wherein the chisel comprises a longitudinal lumen. 
     
     
         4 . A system as in  claim 1 , wherein the receiving assembly of the delivery device comprises a conical outer surface and a longitudinally extending bore. 
     
     
         5 . A system as in  claim 1 , wherein forks of the delivery device comprise at least one of serrations or teeth. 
     
     
         6 . A system as in  claim 1 , wherein the handle of the decorticator comprises a generally cylindrical portion with at least one of raised portions or recesses adapted to assist gripping the handle. 
     
     
         7 . A system as in  claim 1 , wherein the abrasive distal end of the decorticator comprises serrated teeth. 
     
     
         8 . A system as in  claim 1 , wherein chisel further comprises a head at its proximal end that abuts the receiving assembly of the delivery device when the chisel is inserted far enough into the delivery device. 
     
     
         9 . A system as in  claim 1 , wherein the driver assembly further comprises:
 an implant distractor;   a distractor knob; and   an internal actuator coupled between the implant distractor and the distractor knob.   
     
     
         10 . A system as in  claim 9 , wherein the implant shaft of the driver assembly further comprises a keyway feature for preventing relative motion between the tubular shaft of the delivery device and the implant shaft of the driver assembly. 
     
     
         11 . A system as in  claim 9 , wherein the internal actuator comprises a longitudinal shaft positioned within, and longitudinally slidable relative to, the implant shaft of the driver assembly, so as to advance the implant distractor into the implant, causing distraction of the facet joint. 
     
     
         12 . A system as in  claim 1 , wherein the each of the two arms of the driver assembly comprises an engagement feature, and wherein the implant comprises two receiving features for engaging the engagement features of the two arms. 
     
     
         13 . A system as in  claim 12 , wherein the engagement feature on each of the arms comprises a longitudinal ridge extending the length of each of the arms. 
     
     
         14 . A method for distracting a facet joint of a spine via a posterior approach to the spine, the method comprising:
 advancing a distal tip of a chisel into the facet joint via the posterior approach;   decorticating bone adjacent the facet joint using a decorticator disposed over the chisel;   removing the decorticator over the chisel;   advancing a delivery device over the chisel to position anchoring forks of the delivery device in the facet joint;   removing the chisel through the delivery device; and   advancing an implant through the delivery device and into the facet joint to distract the facet joint.   
     
     
         15 . A method as in  claim 14 , wherein advancing the chisel comprises tapping a proximal end of the chisel with a hammer. 
     
     
         16 . A method as in  claim 14 , further comprising advancing the decorticator over the chisel to contact the bone before decorticating, wherein decorticating the bone comprises rotating the decorticator about a shaft of the chisel. 
     
     
         17 . A method as in  claim 16 , wherein advancing the decorticator comprises tapping a proximal end of the decorticator with a hammer. 
     
     
         18 . A method as in  claim 14 , further comprising, after removing the chisel from the delivery device:
 advancing a smaller diameter decorticator through the delivery device; and   decorticating additional bone with the smaller diameter decorticator.   
     
     
         19 . A method as in  claim 14 , wherein the implant is advanced via a driver assembly comprising a shaft, a distal end, a proximal end, and an engagement feature at the distal end for holding the implant. 
     
     
         20 . A method as in  claim 19 , further comprising:
 turning a knob on the proximal end of the driver assembly to release the implant from the engagement feature; and   removing the driver assembly through the delivery device, leaving the implant in the facet joint.   
     
     
         21 . A method as in  claim 20 , further comprising distracting the implant with an implant distractor.