System and methods for spinal fusion
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.
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 to provide a D-shaped circumference formed by the proximal wall, the distal wall, the anterior wall and the posterior wall;
an upper surface of the implant comprising upper surfaces of the proximal wall, the distal wall, the anterior wall and the posterior wall, the upper surface comprising a first anti-migration feature configured to be in contact with the first vertebra while the implant is positioned in the interbody space;
a lower surface of the implant comprising lower surfaces of the proximal wall, distal wall, anterior wall and posterior wall, the lower surface comprising a second anti-migration feature configured to be in contact with the second vertebra while the implant is positioned in the interbody space;
a fusion aperture extending through an entire height of the implant extending from the upper surface of the implant to the lower surface of the implant to permit bone growth therein between the first vertebra and the second vertebra while the implant is positioned in the interbody space; and
a first visualization aperture in the anterior wall and a second visualization aperture in the posterior wall, the first visualization aperture and the second visualization aperture in communication with the fusion aperture, the first and second visualization apertures configured to aid in visualization of bony fusion between the first and second vertebrae.
2. The implant of claim 1 , further comprising at least a portion of a radiopaque marker within at least one of the proximal wall, the distal wall, the anterior wall, and the posterior wall.
3. The implant of claim 1 , further comprising a first radiopaque marker, a second radiopaque marker, and a third radiopaque marker, the first radiopaque marker comprising at least a portion in the proximal wall, the second radiopaque marker comprising at least a portion in the distal wall, and the third radiopaque marker comprising at least a portion in the anterior wall or the posterior wall.
4. The implant of claim 3 , wherein the at least a portion of the third radiopaque marker is in a medial plane of the implant.
5. The implant of claim 1 , wherein the fusion aperture comprises an hourglass shape.
6. The implant of claim 1 , wherein four visualization apertures are on each of the anterior wall and the posterior wall, and wherein all of the visualization apertures are in communication with the fusion aperture.
7. The implant of claim 6 , wherein the four visualization apertures each comprise an oblong shape.
8. The 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.
9. The implant of claim 8 , 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.
10. The 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 an upper surface of the proximal wall or the distal wall and configured to be in contact with the first vertebra while the implant is positioned in the interbody space.
11. The implant of claim 10 , wherein the spike element comprises a radiopaque material.
12. The implant of claim 1 , further comprising a first spike element comprising a portion protruding from an upper surface of the distal wall, and another portion disposed within the distal wall, a second spike comprising a portion protruding from an upper surface of the proximal wall and another portion disposed within the proximal wall, and a third spike element comprising a portion protruding from an upper surface of the anterior wall or the posterior wall and another portion disposed within the anterior wall or the posterior wall.
13. The implant of claim 1 , wherein the first anti-migration feature comprises a first plurality of ridges and the second anti-migration feature comprises a second plurality of ridges.
14. The implant of claim 1 , 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.
15. The implant of claim 1 , wherein the second anti-migration feature is not disposed on at least a portion of the lower surface of the distal wall and at least a portion of the lower surface of the proximal wall.
16. The implant of claim 1 , 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.
17. The implant of claim 1 , wherein the first corner radius of curvature and the second corner radius of curvature are the same.
18. The implant of claim 1 , 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.
19. The implant of claim 18 , 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.
20. The implant of claim 1 , wherein the first length is less than the second length.
21. The implant of claim 1 , wherein the proximal end and the distal end are angled to converge towards each other in the direction of the anterior wall.