Methods of use of an exchange system for soft tissue access pathway

Abstract

Disclosed are 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.

1 . A method of advancing a device along an access tract, comprising the steps of:
 positioning a dilator sheath between an access site and a target site on a bone;   advancing a tubular exchange bushing over the dilator sheath;   advancing a tubular exchange cannula over the exchange bushing;   removing the dilator sheath and the exchange bushing, leaving the exchange cannula in position along the access tract; and   introducing the device through the exchange cannula.   
   
   
       2 . A method as in  claim 1 , wherein the device is an implant. 
   
   
       3 . A method as in  claim 1 , wherein the device is a spinal fusion implant. 
   
   
       4 . A method as in  claim 1 , wherein the device is a spinal motion preservation implant. 
   
   
       5 . A method as in  claim 1 , wherein the device is a site preparation tool. 
   
   
       6 . A method as in  claim 1 , wherein the device has a cross sectional area that is greater than the inside cross sectional area of the dilator sheath. 
   
   
       7 . A method as in  claim 1 , wherein the target site is on the sacrum. 
   
   
       8 . A method as in  claim 1 , wherein the introducing the device step comprises enlarging the diameter of at least a portion of the exchange cannula. 
   
   
       9 . A method as in  claim 8 , comprising radially enlarging a distal tapered portion of the exchange cannula. 
   
   
       10 . A method as in  claim 1 , wherein the access tract has a longitudinal axis which intersects the surface of the bone at an angle, and the distal end of the exchange cannula is beveled at an angle that corresponds to the angle at which the axis intersects the surface of the bone.