Facet arthroplasty devices and methods

Abstract

Devices and surgical methods treat various types of adult spinal pathologies, such as degenerative spondylolisthesis, spinal stenosis, degenerative lumbar scoliosis, and kypho-scoliosis. Various types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments are used to perform the surgical procedures.

1 . A prosthesis to replace a cephalad portion of a left natural facet joint on a vertebral body and a cephalad portion of a right natural facet joint on the vertebral body, the prosthesis comprising: 
 prosthesis bodies accommodating fixation to the vertebral body at or near respective left and right pedicles without support of a lamina,    an artificial left facet joint structure on the left prosthesis body prosthesis body adapted and configured to replace a cephalad portion of the left natural facet joint after removal of a portion of the vertebral arch; and    an artificial right facet joint structure on the right prosthesis body adapted; and    configured to replace a cephalad portion of the right natural facet joint.    
     
     
         2 - 5 . (canceled)  
     
     
         6 . A prosthesis according to  claim 1  wherein at least one of the left and right artificial facet joint structures includes means for replacing a cephalad portion of a respective one of the left and right natural facet joints after removal of the cephalad portion of the respective natural facet joint from the vertebral body.  
     
     
         7 . A prosthesis according to  claim 1  wherein the left and right artificial facet joint structures include means for replacing a cephalad portion of the left and right natural facet joints after removal of the cephalad portion of the left and right natural facet joints from the vertebral body.  
     
     
         8 . (canceled)  
     
     
         9 . (canceled)  
     
     
         10 . A prosthesis according to  claim 1  wherein at least one of the left and right artificial facet joint structures includes means for replacing a cephalad portion of at least one of the left and right natural facet joints after removal of at least one inferior articular process and at least a portion of a lamina from the vertebral body.  
     
     
         11 . A prosthesis according to  claim 1  wherein the left and right artificial facet joint structures include means for replacing a cephalad portion of the left and right natural facet joints after removal of left and right inferior articular processes and at least a portion of a lamina from the vertebral body.  
     
     
         12 . (canceled)  
     
     
         13 . A method of replacing, on a vertebral body, a cephalad portion of a left natural facet joint and a cephalad portion of a right natural facet joint using the prosthesis as defined in  claim 1  to provide improved support for the spinal column, the method comprising the steps of: 
 (i) removing the cephalad portions of the left and right natural facet joints from the vertebral body, and    (ii) after step (i), fixing the prosthesis as defined in  claim 1  to the vertebral body to replace both removed cephalad portions of the first and second natural facet joints with the first and second artificial facet joint structures.    
     
     
         14 . A method according to  claim 13  wherein the removing step includes removing left and right inferior articular processes and at least a portion of a lamina from the vertebral body.  
     
     
         15 - 31 . (canceled)