Percutaneous technique and implant for expanding the spinal canal

Abstract

The present invention expands a spinal canal by drilling a cylindrical passage in each pedicle of a vertebra, making a circumferential pedicle cut (osteotomy) through each pedicle from within the passage, separating each pedicle cut by inserting an implant into the passage which distracts the pedicle cut to expand the spinal canal, and securing each pedicle cut, allowing the vertebra to heal with the spinal canal expanded. The implant includes an outer sleeve, an inner bolt, and expandable flanges. The outer sleeve includes an upper portion and a lower portion, with the expandable flanges connected to the lower portion and housed within the upper portion. Rotation of the inner bolt causes the upper and lower portions of the outer sleeve to separate, causing the pedicle cut to widen and the expandable flanges to radially extend into and stabilize the widened pedicle cut to effectuate expansion of the spinal canal.

1 . A method for expanding a spinal canal, comprising the steps of: 
 cutting a vertebral pedicle through to the spinal canal in at least one location;    widening each vertebral cut to expand the spinal canal; and    securing each widened vertebral cut; whereby the vertebra heals with the spinal canal expanded.    
   
   
       2 . A method for expanding a spinal canal, comprising the steps of: 
 drilling at least one passage into a vertebra;    performing a vertebral cut from within the passage through to the spinal canal and through to an outside of the vertebra;    widening each vertebral cut to enlarge the spinal canal; and    stabilizing each vertebral cut; whereby the vertebra heals with the spinal canal expanded.    
   
   
       3 . The method of  claim 2 , wherein the vertebra is cut through the pedicle.  
   
   
       4 . The method of  claim 2 , further comprising a preliminary step of introducing a guide wire into the vertebra to guide the drilling of the at least one passage into the vertebra.  
   
   
       5 . The method of  claim 4 , wherein a cannulated drill is positioned over the guide wire to drill the at least one passage into the vertebra.  
   
   
       6 . The method of  claim 2 , wherein the at least one passage into the vertebra is located in the pedicle of the vertebra, the passage forming a hollow, cylindrical column within the pedicle.  
   
   
       7 . The method of  claim 2 , wherein the vertebra is cut circumferentially from within the passage using a side-cutting instrument.  
   
   
       8 . The method of  claim 7 , wherein the side cutting instrument includes a cutting surface that projects radially outward and is rotatably movable to perform the circumferential vertebral cut.  
   
   
       9 . The method of  claim 2 , wherein an implant, inserted into the passage, separates the vertebral cut to expand the spinal canal.  
   
   
       10 . The method of  claim 9 , wherein the implant includes external threads and is threadably introduced into the passage, the external threads of the implant engaging walls of the passage on either side of the vertebral cut.  
   
   
       11 . The method of  claim 10 , wherein the implant includes an outer sleeve and an inner bolt in communication with the outer sleeve, wherein movement of the inner bolt in relation to the outer sleeve widens the vertebral cut to expand the spinal canal.  
   
   
       12 . The method of  claim 11 , wherein the outer sleeve of the implant includes an upper portion and a lower portion, wherein movement of the inner bolt in relation to the outer sleeve separates the upper portion from the lower portion, thereby widening the vertebral cut due to the threadable engagement of the implant to the walls of the passage on either side of the vertebral cut.  
   
   
       13 . The method of  claim 12 , wherein the implant further includes expandable flanges, wherein the flanges extend radially outward from the implant upon separation of the upper portion from the lower portion and are positioned within the vertebral cut to stabilize the vertebral cut.  
   
   
       14 . The method of  claim 2 , further comprising the step of inserting an implant into the passage to widen the vertebral cut and expand the spinal canal.  
   
   
       15 . The method of  claim 14 , wherein comprising the step of operating the implant to radially extend flanges outward from the implant and into the widened vertebral cut, thereby stabilizing the vertebral cut.  
   
   
       16 . A method for expanding a spinal canal, comprising the steps of: 
 drilling at least one passage into a vertebra;    cutting the vertebra through to the spinal canal in at least one location;    widening each vertebral cut to expand the spinal canal; and    securing each widened vertebral cut; whereby the vertebra heals with the spinal canal expanded.    
   
   
       17 . The method of  claim 16 , wherein the vertebra is cut through the pedicle.  
   
   
       18 . The method of  claim 16 , wherein the at least one passage drilled into the vertebra is located in at least a portion of a pedicle of the vertebra, the passage forming a hollow, cylindrical column within at least a portion of the pedicle.  
   
   
       19 . A method for expanding a spinal canal, comprising the steps of: 
 drilling at least one passage into a vertebra;    inserting a side cutting instrument into the passage and making a vertebral cut from within the passage through to the spinal canal and through to an outside of the vertebra; and    inserting an implant into the passage, the implant engaging walls of the passage on either side of the vertebral cut, and    operating the implant to distract the vertebral cut and expand the spinal canal, thereby stabilizing the vertebral cut until the vertebra heals with the spinal canal expanded.    
   
   
       20 . The method of  claim 19 , wherein operating the implant includes turning an inner bolt about its longitudinal axis, the turning inner bolt engaging upper and lower portions of an outer sleeve to separate the lower portion from the upper portion, the separation of the lower and the upper portions serving to distract the vertebral cut.  
   
   
       21 . The method of  claim 19 , wherein the vertebra is cut through the pedicle.  
   
   
       22 . The method of  claim 19 , wherein the at least one passage drilled into the vertebra is located in a pedicle of the vertebra, the passage forming a hollow, cylindrical column within the pedicle.