Method and apparatus for spinal distraction

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 distraction device, comprising: 
 an elongate body, having at least a proximal component releasably connected to a distal component;    a proximal thread on the proximal component, having a first pitch and a first major diameter;    a distal thread on the distal component, having a second pitch and a second major diameter;    wherein the first pitch is different than the second pitch and the first major diameter is greater than the second major diameter.    
   
   
       2 . A distraction device as in  claim 1 , wherein the first major diameter is within the range of from about 10 mm to about 15 mm.  
   
   
       3 . A distraction device as in  claim 2 , wherein the second major diameter is no greater than about 98% of the first major diameter.  
   
   
       4 . A distraction device as in  claim 1 , wherein the elongate body has a length within the range of from about 1.25 inches to about 2.25 inches.  
   
   
       5 . A distraction device as in  claim 1 , wherein each of the proximal thread and the distal thread has an axial length within the range of from about 0.5 inches to about 1.25 inches.  
   
   
       6 . A distraction device as in  claim 1 , further comprising complementary threaded surfaces in between the proximal component and the distal component.  
   
   
       7 . A distraction device as in  claim 1 , wherein the elongate body comprises stainless steel.  
   
   
       8 . A distraction device as in  claim 1 , wherein the elongate body comprises titanium.  
   
   
       9 . A distraction device 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.  
   
   
       10 . A distraction device as in  claim 1 , wherein each of the proximal thread and the distal thread extends clockwise around the body, viewed in a proximal to distal direction.  
   
   
       11 . A distraction device as in  claim 1 , wherein each of the proximal thread and the distal thread are self tapping.  
   
   
       12 . A distraction device as in  claim 2 , wherein the first major diameter is within the range of from about 12 mm to about 13 mm.  
   
   
       13 . A distraction device as in  claim 1 , wherein the second major diameter is about 9 mm.  
   
   
       14 . A distraction device as in  claim 1 , wherein the second pitch is less than the first pitch.  
   
   
       15 . A distraction device as in  claim 1 , wherein the first pitch is within the range of from about 10 to about 15 turns per inch.  
   
   
       16 . A distraction device as in  claim 1 , wherein the second pitch is within the range of from about 10 to about 20 turns per inch.  
   
   
       17 . A distraction device as in  claim 1 , wherein the second pitch is at least about 105% of the first pitch.  
   
   
       18 . A distraction device as in  claim 1 , wherein the second pitch is at least about 110% of the first pitch.  
   
   
       19 . A distraction device as in  claim 1 , wherein the second pitch is at least about 125% of the first pitch.  
   
   
       20 . A distraction device as in  claim 1 , further comprising a releasable coupling, for releasably engaging a rotatable driver tool.  
   
   
       21 . A temporary distraction device, comprising: 
 an elongate body, having at least a proximal component and a distal component;    a proximal bone engaging thread on the proximal component;    a distal bone engaging thread on the distal component, axially separated from the proximal bone engaging thread; and    a rotatable driver;    wherein rotating the rotatable driver changes the axial separation between the proximal and distal bone engaging threads.    
   
   
       22 . A temporary distraction device as in  claim 21 , wherein the elongate body has a length within the range of from about 1.25 inches to about 2.25 inches.  
   
   
       23 . A temporary distraction device as in  claim 21 , wherein each of the proximal thread and the distal thread has an axial length within the range of from about 0.5 inches to about 1.25 inches.  
   
   
       24 . A temporary distraction device as in  claim 21 , further comprising complementary threaded surfaces in between the proximal component and the distal component.  
   
   
       25 . A temporary distraction device as in  claim 21 , wherein the elongate body comprises stainless steel.  
   
   
       26 . A temporary distraction device as in  claim 21 , wherein the elongate body comprises titanium.  
   
   
       27 . A temporary distraction device as in  claim 21 , wherein each of the proximal thread and the distal thread extends counterclockwise around the body, viewed in a proximal to distal direction.  
   
   
       28 . A temporary distraction device as in  claim 21 , wherein each of the proximal thread and the distal thread extends clockwise around the body, viewed in a proximal to distal direction.  
   
   
       29 . A temporary distraction device as in  claim 21 , wherein each of the proximal thread and the distal thread are self tapping.  
   
   
       30 . A temporary distraction device as in  claim 21 , further comprising a releasable coupling, for releasably engaging the rotatable driver.