Spinal fusion device and method of using same

Abstract

A spinal fusion device having a spacer and a fastener and an associated method of use are disclosed. The spinal fusion device preferably has features to prevent excessive insertion of the spacer between two adjacent vertebra; to ensure proper fenestration, to ensure tight engagement between the spacer and the fastener and between the spinal fusion device and two adjacent vertebrae, to hinder back-out of screws used by the fastener, and to promote compaction and displacement of bone graft material to enhance the fusion process.

1 . A spinal fusion device kit comprising:
 a back-fillable spacer, having a posterior portion and an anterior portion, the back-fillable spacer configured to fit between two adjacent vertebrae;   a fastener, having a posterior side and an anterior side, the fastener configured to engage the anterior portion of the spacer and configured to be fastened to two adjacent vertebrae; and   a plurality of spacer protrusions coupled to the anterior portion of the spacer and extending in at least one of a superior and an inferior direction, wherein the plurality of spacer protrusions are configured to engage an anterior portion of two adjacent vertebrae.   
     
     
         2 - 9 . (canceled) 
     
     
         10 . A method for fusing adjacent vertebrae comprising the steps of:
 inserting a back-fillable spacer having a posterior portion and an anterior portion between two adjacent vertebrae comprising a superior vertebra having an inferior endplate and an inferior vertebra having a superior endplate;   inserting bone graft material between the two adjacent vertebrae and into a cavity defined by the spacer;   engaging a fastener having a posterior side and an anterior side with the anterior portion of the spacer; and   fastening the fastener to the two adjacent vertebrae;   wherein the spacer has a plurality of spacer protrusions, protruding from the anterior portion of the spacer and extending in at least one of a superior and an inferior direction, and wherein the plurality of spacer protrusions are configured to engage an anterior portion of the two adjacent vertebrae.   
     
     
         11 . The method according to  claim 10  further comprising the step of gouging the inferior endplate of the superior vertebra and the superior endplate of the inferior vertebra using a gouge having a first end having been inserted into a gouge aligner positioned on the spacer. 
     
     
         12 . The method according to  claim 10  further comprising the step of locking the fastener into the anterior portion of the spacer by way of a complementary locking arrangement on the fastener and the spacer. 
     
     
         13 . The method according to  claim 12  comprising the step of locking the fastener relative to the spacer in a plurality of locking positions. 
     
     
         14 . The method according to  claim 10  further comprising the step of compacting and displacing the bone graft material by posterior movement of the fastener toward the spacer, wherein the fastener further comprises at least one fastener protrusion, protruding from the posterior side of the fastener. 
     
     
         15 . The method according to  claim 10  including the step of fastening the plurality of spacer protrusions to the two adjacent vertebrae. 
     
     
         16 . The method according to  claim 10  wherein the spacer is inserted between the two vertebrae in a posterior direction to an extent that the plurality of spacer protrusions engages the anterior portion of the two adjacent vertebrae. 
     
     
         17 . The method according to claim  9  wherein the fastener is fastened to at least one of the two adjacent vertebrae using a fastening device inserted through one of the through-holes of the fastener, and wherein the method further comprises the step of rotating an anti-backout device into a position over the fastener device after the fastening device has been inserted into the body of the at least one vertebra. 
     
     
         18 . A spinal fusion device kit comprising:
 a back-fillable spacer, having a posterior portion and an anterior portion, the back-fillable spacer configured to fit between two adjacent vertebrae; and   a fastener, having a posterior side and an anterior side, the fastener configured to engage the anterior portion of the spacer and configured to be fastened to two adjacent vertebrae;   wherein the fastener has at least one fastener protrusion, protruding from the posterior side of the fastener, and configured to displace fusion material within a cavity defined by the spacer.   
     
     
         19 - 21 . (canceled)