Systems 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 system for spinal fusion between adjacent vertebrae, the system comprising:
 an implant configured to be positioned in an interbody space between a first vertebra and a second vertebra,   wherein the implant comprises a proximal wall, a distal wall, an anterior wall, a posterior wall, an upper surface configured to engage the first vertebra, a lower surface configured to engage the second vertebra, and a receiving aperture; and   an insertion instrument configured to engage the receiving aperture of the implant and position the implant in the interbody space.   
     
     
         2 . The system of  claim 1 , wherein the insertion instrument comprises:
 an elongate element extending between a distal end and a proximal end, wherein the elongate element comprises an inner bore extending therein; and   an inserter shaft disposed within the inner bore of the elongate element, wherein the inserter shaft comprises a distal end configured to engage the receiving aperture of the implant.   
     
     
         3 . The system of  claim 2 , wherein the insertion instrument further comprises:
 a thumbwheel housing coupled to the proximal end of the elongate element;   a thumbwheel disposed within the thumbwheel housing and rotatably coupled to a proximal end of the inserter shaft; and   a handle coupled to a proximal end of the thumbwheel housing.   
     
     
         4 . The system of  claim 3 , wherein the insertion instrument further comprises:
 a spacer disposed within the thumbwheel housing between the thumbwheel and the inserter shaft to reduce friction therebetween;   a set screw configured to couple the thumbwheel to the inserter shaft; and   a spring disposed within the inner bore of the elongate element that is configured to stabilize the inserter shaft.   
     
     
         5 . The system of  claim 2 , wherein the insertion instrument further comprises a distal head configured to couple to the distal end of the elongate element and dimensioned to engage the implant, wherein the distal end of the inserter shaft is configured to extend through the distal head to engage the receiving aperture of the implant. 
     
     
         6 . The system of  claim 5 , wherein the distal head of the insertion instrument comprises a distal head ridge, and wherein the implant further comprises a grooved purchase region extending away from the receiving aperture and dimensioned to receive the distal head ridge therein. 
     
     
         7 . The system of  claim 1 , wherein the implant further comprises:
 a plurality of upper ridges disposed on an upper surface of each of the anterior wall and the posterior wall; and   a plurality of lower ridges disposed on a lower surface of each of the anterior wall and the posterior wall,   wherein the plurality of upper ridges and the plurality of lower ridges are configured to resist proximal movement when engaged in the interbody space.   
     
     
         8 . The system of  claim 7 , wherein each ridge of the plurality of upper ridges and the plurality of lower ridges extends in a direction substantially perpendicular or perpendicular to the anterior and posterior walls. 
     
     
         9 . The system of  claim 1 , wherein the anterior wall has a first length, and the posterior wall has a second length different than the first length. 
     
     
         10 . The system of  claim 9 , wherein the second length is greater than the first length. 
     
     
         11 . The system of  claim 1 , wherein the implant further comprises an anti-migration feature configured to resist proximal movement when engaged in the interbody space, wherein the anti-migration feature comprises:
 a portion disposed within one wall selected from the proximal wall, the distal wall, the anterior wall, and the posterior wall;   a first end protruding from the upper surface; and   a second end protruding from the lower surface.   
     
     
         12 . The system of  claim 11 , wherein the portion, the first end, and the second end of the anti-migration feature are coupled to one another such that the first end couples to the portion and the second end couples to the portion opposite the first end. 
     
     
         13 . The system of  claim 1 , wherein the implant further comprises:
 a fusion aperture extending between the upper surface and the lower surface, wherein the fusion aperture is configured to promote bone growth therethrough when the implant is positioned in the interbody space; and   a visualization aperture configured to communicate with the fusion aperture extending through one or more of the anterior wall or the posterior wall.   
     
     
         14 . The system of  claim 13 , further comprising an osteoinductive material disposed within the fusion aperture and configured to promote bone growth. 
     
     
         15 . The system of  claim 1 , wherein the implant further comprises a radiopaque marker positioned along a medial plane of the implant, wherein the radiopaque marker is disposed in one or more of the anterior wall and the posterior wall. 
     
     
         16 . A system for spinal fusion between adjacent vertebrae, the system comprising:
 an implant configured to be positioned in an interbody space between a first vertebra and a second vertebra,   wherein the implant comprises a proximal wall, a distal wall, an anterior wall, a posterior wall, an upper surface configured to engage the first vertebrae, a lower surface configured to engage the second vertebrae, and a receiving aperture; and   an insertion instrument configured to engage the receiving aperture of the implant and position the implant in the interbody space, wherein the insertion instrument comprises:
 an elongate element extending between a distal end and a proximal end, the elongate element having an inner bore extending therethrough; 
 a distal head configured to couple to the distal end of the elongate element and dimensioned to engage the implant; and 
 an inserter shaft disposed within the inner bore of the elongate element, wherein the inserter shaft comprises a distal end configured to extend through the distal head and engage the receiving aperture of the implant. 
   
     
     
         17 . The system of  claim 16 , wherein the implant further comprises:
 a plurality of upper ridges disposed on an upper surface of each of the anterior wall and the posterior wall;   a plurality of lower ridges disposed on a lower surface of each of the anterior wall and the posterior wall; and   an anti-migration feature comprising:
 a portion disposed within one wall selected from the proximal wall, the distal wall, the anterior wall, and the posterior wall, 
 a first end protruding from the upper surface thereof, and 
 a second end protruding from the lower surface thereof, 
   wherein the plurality of upper ridges, the plurality of lower ridges, and the anti-migration feature are configured to resist proximal movement when engaged in the interbody space, and   wherein the portion, the first end, and the second end of the anti-migration feature are coupled to one another such that the first end couples to the portion and the second end couples to the portion opposite the first end.   
     
     
         18 . The system of  claim 16 , wherein the implant further comprises:
 a fusion aperture extending between the upper surface and the lower surface, wherein the fusion aperture is configured to promote bone growth therethrough when the implant is positioned in the interbody space;   a visualization aperture configured to communicate with the fusion aperture extending through one or more of the anterior wall and the posterior wall; and   a radiopaque marker positioned along a medial plane of the implant, wherein the radiopaque marker is disposed in one or more of the anterior wall and the posterior wall.   
     
     
         19 . The system of  claim 18 , further comprising an osteoinductive material disposed within the fusion aperture and configured to promote bone growth. 
     
     
         20 . The system of  claim 16 , wherein the insertion instrument further comprises:
 a thumbwheel housing coupled to the proximal end of the elongate element;   a thumbwheel disposed within the thumbwheel housing and rotatably coupled to a proximal end of the inserter shaft;   a handle coupled to a proximal end of the thumbwheel housing;   a spacer disposed within the thumbwheel housing between the thumbwheel and the inserter shaft to reduce friction therebetween;   a set screw configured to couple the thumbwheel to the inserter shaft; and   a spring disposed within the inner bore of the elongate element and configured to stabilize the inserter shaft.