Compressible fixation apparatus for spinal surgery

Abstract

A spinal fixation apparatus is configured with a pair of endpieces and an intermediate compressible portion. The compressible portion may comprise a pair of mating sliders comprising toothed arms attached to the endpieces. A gear engages the toothed arms. When the gear is rotated, the sliders bring the endpieces together, compressing the apparatus.

1 . A method of enhancing fusion of a graft in the cervical spine comprising: 
 accessing an anterior portion of cervical vertebrae;    affixing endpieces of a compressible fixation device to the vertebral bodies on either side of a graft;    adjusting the distance between said endpieces into a compressed position, thereby compressing the graft; and    locking the device into the compressed position.    
   
   
       2 . The method of  claim 1 , wherein the endpieces are affixed to the mid-substance of the vertebral bodies.  
   
   
       3 . The method of  claim 1 , wherein said affixing comprises screwing the endpieces to the vertebral bodies.  
   
   
       4 . The method of  claim 1 , wherein said adjusting comprises rotating a gear that mates with teeth located on the endpieces to draw the endpieces toward each other.  
   
   
       5 . The method of  claim 4 , where said locking is achieved by installing a set screw to prevent the gear from rotating.  
   
   
       6 . The method of  claim 1 , wherein said adjusting comprises sliding the endpieces toward each other.  
   
   
       7 . A method of enhancing fusion of a graft in a multilevel cervical vertebral fusion comprising: 
 accessing an anterior cervical spinal portion;    removing some or all of at least two cervical spinal disks to create a space between cervical vertebrae;    placing at least one graft in the space created by the removal of some or all of the at least two cervical spinal disks;    affixing respective endpieces of a compressible fixation device to vertebral bodies superior and inferior to the graft;    affixing at least one intermediate endpiece of a compressible fixation device to an intermediate vertebral body between said superior and inferior vertebral bodies;    adjusting the distance between said endpieces into a compressed position, thereby compressing the graft; and    locking the device into the compressed position.    
   
   
       8 . The method of  claim 7 , wherein the endpieces are affixed to the mid-substance of the vertebral bodies.  
   
   
       9 . The method of  claim 7 , wherein said affixing comprises screwing the endpieces to the vertebral bodies.  
   
   
       10 . The method of  claim 7 , wherein said adjusting comprises rotating a gear that mates with teeth located on the endpieces to draw the endpieces toward each other.  
   
   
       11 . The method of  claim 10 , where said locking is achieved by installing a set screw to prevent the gear from rotating.  
   
   
       12 . The method of  claim 7 , wherein said adjusting comprises sliding the endpieces toward each other.