System and methods for spinal fusion

Abstract

A system and method for spinal fusion comprising a spinal fusion implant of non-bone construction releasably coupled to an insertion instrument dimensioned to introduce the spinal fusion implant into any of a variety of spinal target sites, in particular into the thoracic region of the spine.

What is claimed is: 
     
         1 . A spinal fusion implant configured to be positioned in an interbody space between a first vertebra and a second vertebra, comprising:
 a proximal wall, a distal wall, an anterior wall and a posterior wall, the anterior wall having a first length and being configured to face an anatomically anterior aspect of the interbody space while the implant is positioned in the interbody space, the posterior wall having a second length and being configured to face an anatomically posterior aspect of the interbody space while the implant is positioned in the interbody space, the anterior wall meeting the distal wall at a first corner having a first corner radius of curvature and meeting the proximal wall at a second corner having a second corner radius of curvature, the posterior wall meeting the distal wall at a third corner having a third corner radius of curvature and meeting the proximal wall at a fourth corner having a fourth corner radius of curvature, the first corner radius of curvature and the second corner radius of curvature being greater than the third corner radius of curvature and the fourth corner radius of curvature such that the second length is greater than the first length.   
     
     
         2 . The spinal fusion implant of  claim 1 , further including an upper surface comprising upper surfaces of the proximal wall, the distal wall, the anterior wall and the posterior wall, and a lower surface comprising lower surfaces of the proximal wall, distal wall, anterior wall and posterior wall. 
     
     
         3 . The spinal fusion implant of  claim 2 , further including a fusion aperture extending through an entire height of the implant extending from the upper surface to the lower surface to permit bone growth therethrough when the implant is positioned in the interbody space. 
     
     
         4 . The spinal fusion implant of  claim 3 , wherein the upper surface includes at least a first anti-migration feature configured to be in contact with the first vertebra when the implant is positioned in the interbody space. 
     
     
         5 . The spinal fusion implant of  claim 3 , further including at least a first visualization aperture in the anterior wall and in communication with the fusion aperture. 
     
     
         6 . The spinal fusion implant of  claim 5 , further including at least a second visualization aperture in the posterior wall and in communication with the fusion aperture. 
     
     
         7 . The spinal fusion implant of  claim 6 , wherein the anterior wall includes four visualization apertures and the posterior wall includes four visualization apertures, wherein all of the visualization apertures are in communication with the fusion aperture. 
     
     
         8 . The spinal fusion implant of  claim 7 , wherein the four visualization on the anterior wall and the four visualization apertures on the posterior wall each have an oblong shape. 
     
     
         9 . The spinal fusion implant of claiml, further comprising a first radiopaque marker situated in the anterior wall along a medial plane of the implant and a second radiopaque marker situated in the posterior wall along the medial plane of the implant. 
     
     
         10 . The spinal fusion implant of  claim 3 , wherein the fusion aperture comprises an hourglass shape. 
     
     
         11 . The spinal fusion implant of  claim 1 , wherein the proximal wall comprises a threaded tool engagement aperture configured to receive a corresponding portion of an insertion tool for delivering the implant to a target position in the interbody space. 
     
     
         12 . The spinal fusion implant of  claim 11 , wherein the proximal wall further comprises a pair of lateral grooves configured to receive another corresponding portion of the insertion tool, the pair of lateral grooves extending horizontally in opposing directions from the threaded tool engagement aperture. 
     
     
         13 . The spinal fusion implant of  claim 1 , further comprising a spike element comprising at least a portion disposed within the proximal wall or the distal wall, the spike element comprising a portion protruding from the upper surface and configured to be in contact with the first vertebra while the implant is positioned in the interbody space. 
     
     
         14 . The spinal fusion implant of  claim 13 , wherein the spike element comprises a radiopaque material. 
     
     
         15 . The spinal fusion implant of  claim 4 , wherein the first anti-migration feature comprises a first plurality of ridges. 
     
     
         16 . The spinal fusion implant of  claim 15 , wherein the first anti-migration feature is not disposed on at least a portion of the upper surface of the distal wall and the upper surface of the proximal wall. 
     
     
         17 . The spinal fusion implant of  claim 2 , wherein a portion of the upper surface and a portion of the lower surface of the distal wall are angled relative to one another to provide a tapered distal portion. 
     
     
         18 . The spinal fusion implant of  claim 1 , wherein the first corner radius of curvature and the second corner radius of curvature are the same. 
     
     
         19 . The spinal fusion implant of  claim 18 , wherein the first corner radius of curvature and the second corner radius of curvature are four times greater than the third corner radius of curvature and the fourth corner radius of curvature. 
     
     
         20 . The spinal fusion implant of  claim 19 , wherein the first corner radius of curvature and the second corner radius of curvature are approximately ¼ inch and the third corner radius of curvature and the fourth corner radius of curvature are approximately 1/16 inch. 
     
     
         21 . The spinal fusion implant of  claim 1 , wherein the posterior wall has a height that is greater than the anterior wall.