Spinal implant

Abstract

A spinal implant with associated surgical tools, tool sets and methods for percutaneously accessing and preparing treatment sites within the spine for subsequent treatment procedures. The treatment site may be an inter-vertebral motion segments in the lumbar and sacral regions of the spine. The tool set may comprise introducer tools and bone dilators for accessing and tapping into a targeted site, such as, for example, the anterior surface of the S1 vertebral body. The tool set may also comprise cutters and extractors for preparing the treatment site for subsequent treatment procedures. The tool set may additionally comprise a bone graft inserter, an exchange system, and/or a temporary distraction tool for further preparing the treatment site for subsequent treatment procedures.

What is claimed is: 
     
         1 . An axially-extending implantable rod for extending between two adjacent vertebral bodies in a spine, said rod comprising:
 a distal piece that has a first external thread on an external surface of the distal portion for directly engaging with a first vertebral body;   a proximal piece that has a second external thread on an external surface of the proximal piece for directly engaging a second vertebral body;   an internal bore extending from the distal piece and through the proximal piece portion; and   an intermediate member positioned within the internal bore extending between the distal piece and the second piece, the intermediate member coupling the first and second pieces together.   
     
     
         2 . The implantable rod as in  claim 1 , wherein the elongate body comprises stainless steel. 
     
     
         3 . The implantable rod as in  claim 1 , wherein each of the proximal thread and the distal thread extends counterclockwise around the body, viewed in a proximal to distal direction. 
     
     
         4 . The implantable rod as in  claim 1 , wherein each of the proximal thread and the distal thread are self tapping. 
     
     
         5 . The implantable rod as in  claim 1 , further comprising a releasable coupling, for releasably engaging a rotatable driver tool. 
     
     
         6 . The implantable rod as in  claim 1 , further comprising complementary threaded surfaces in between the proximal component and the distal component. 
     
     
         7 . An access assembly, for guiding instrumentation through soft tissue to a point on the spine, the assembly comprising:
 an elongate, tubular guide pin introducer;   a blunt tipped stylet, slideably positionable within the guide; and   a guide pin, slideably positionable within the guide pin introducer.   
     
     
         8 . An access assembly as in  claim 7 , wherein the guide pin comprises a beveled distal end. 
     
     
         9 . An access assembly as in  claim 7 , wherein the guide pin comprises a proximal handle. 
     
     
         10 . An access assembly as in  claim 9 , wherein the handle is removably carried by the guide pin. 
     
     
         11 . An access assembly as in  claim 7 , wherein the stylet comprises a proximal handle. 
     
     
         12 . An access assembly as in  claim 7 , wherein the guide pin comprises a sharpened distal tip. 
     
     
         13 . An access assembly as in  claim 7 , wherein the proximal handle on the stylet is releasably engageable with the guide pin introducer. 
     
     
         14 . An access assembly as in  claim 7 , wherein the guide pin comprises a proximal connector for connection to a guide pin extension. 
     
     
         15 . A cutter, for disrupting material in an intervertebral space, the cutter adapted to extend through a trans-sacral axial bore along an axis extending cephalad from a sacral vertebral body through at least one vertebral body end plate cephalad of the S-1 vertebral body, the cutter comprising:
 a cutter blade;   a first side surface on the cutter blade for positioning adjacent a vertebral end plate when the cutter blade is oriented generally transverse to the axis;   a second side surface on the blade, separated from the first side surface by a blade thickness;   a first edge on the blade;   a second edge on the blade; and   at least one cutting edge on at least one of the first and second edges.   
     
     
         16 . A cutter as in  claim 15 , wherein the cutting edge is coplanar with the first side surface. 
     
     
         17 . A cutter as in  claim 15 , wherein the cutting edge is coplanar with the second side surface. 
     
     
         18 . A cutter as in  claim 15 , wherein the cutting edge is centered on a plane positioned in-between the first side surface and the second side surface. 
     
     
         19 . A cutter as in  claim 15 , comprising a first cutting edge on the first edge and a second cutting edge on the second edge. 
     
     
         20 . A cutter as in  claim 15 , wherein the elongate ribbon inclines radially outwardly from an axis of rotation.