Spinal fusion system
A spinal fusion system for positioning between two vertebral bodies is presented. The system can have a substantially rigid body and a substantially rigid plate connected to a portion of the posterior face of the substantially rigid body that extends away from and substantially transverse to the posterior face of the substantially rigid body. The system also has a first implant body and a second implant body configured to matingly connect to one another with at least a portion of the substantially rigid plate positioned therebetween. The combination of the first and second implant bodies and the substantially rigid plate is configured for insertion between the two vertebral bodies.
1. A spinal fusion system for positioning between a first and second vertebral body, the system comprising:
a rigid titanium body having a longitudinal axis and a first modulus of elasticity, and a posterior face, the rigid body defining at least one fastener bore therethrough, each bore configured for receipt of at least one fastener, wherein each fastener comprises a bone screw having a head and a threaded shank and is configured for insertion into a vertebral body;
a rigid titanium plate integral to a portion of the posterior face of the rigid body, extending away from and transverse to the posterior face of the rigid body, the rigid plate defines a plurality of cavities therethrough; and
a first thermoplastic implant body and a second thermoplastic implant body wherein the first implant body and the second implant body each have a first inner and a second outer surface and wherein the first implant body and the second implant body connect at their respective first surfaces, the first surfaces having a plurality of projections, and within each of the cavities are matingly connected at their first respective surfaces by the plurality of projections of the first implant body interlocking with the plurality of projections of the second implant body, each body having a modulus of elasticity less than or equal to the first modulus of elasticity, wherein the first and second implant bodies are configured to matingly connect to one another with the rigid plate positioned therebetween, and wherein the combination of the first and second implant bodies and the rigid plate is configured for insertion between the first and second vertebral bodies, and
further comprising a flexible retainer pin for retaining one of the at least one bone screw in a respective fastener bore, the flexible retainer pin positioned through a retaining bore in a portion of the head of the bone screw, wherein a portion of the flexible retainer pin juts out from at least one end of a wall defined by the retaining bore, and wherein the flexible retaining pin is configured to bias toward the head of the bone screw during insertion of the bone screw into the fastener bore, making its effective length less than the diameter of the fastener bore, and bias back to an original position after insertion, thereby retaining the bone screw within the fastener bore.
2. The spinal fusion system of claim 1 , wherein the rigid plate is bisected by a first plane and wherein the longitudinal axis is contained in the first plane.
3. The spinal fusion system of claim 2 , wherein the at least one fastener bore comprises a plurality of fastener bores, and wherein the at least one bone screw comprises a first and second bone screw, the first bone screw being angled upwardly with respect to the first plane and the second bone screw being angled downwardly with respect to the first plane.
4. The spinal fusion system of claim 3 , wherein the first and second Bone screws are oppositely disposed at equal angles.
5. The spinal fusion system of claim 4 , wherein the equal angles are between 20 degrees and 45 degrees.
6. The spinal fusion system of claim 5 , wherein the equal angles are 35 degrees.
7. The spinal fusion system of claim 1 wherein the thermoplastic material comprises polyetheretherketone.
8. The spinal fusion system of claim 1 , wherein at least one of the second surfaces of the first implant body and the second implant body are ramped downwardly away from the rigid body.
9. The spinal fusion system of claim 8 , wherein at least one of the second surface of the first implant body and the second implant body define ridges.
10. The spinal fusion system of claim 1 , wherein the flexible retainer pin comprises a distal cross member positioned adjacent to its distal end and a proximal cross member positioned adjacent to its proximal end for retaining the flexible retainer pin within the retaining bore.
11. The spinal fusion system of claim 1 , wherein the first implant body has a first thickness and the second implant body has a second thickness.
12. The spinal fusion system of claim 11 , wherein the first thickness is equal to the second thickness.
13. A spinal fusion system for positioning between a first and second vertebral body, the system comprising: a rigid titanium body having a longitudinal axis and a posterior face, the rigid body defining at least one fastener bore therethrough, each bore configured for receipt of at least one bone screw, wherein each bone screw has a head and a threaded shank and is configured for insertion into one of the first or second vertebral bodies; a rigid plate integrally connected to a portion of the posterior face of the rigid body, extending away from and transverse to the posterior face of the rigid body, the rigid plate defines a plurality of cavities therethrough; and a first thermoplastic implant body and a second thermoplastic implant body wherein the first implant body and the second implant body each have a first and a second surface and wherein the first implant body and the second implant body connect at their respective first surfaces, the first surfaces having a plurality of projections, and within each of the cavities are matingly connected at their first respective surfaces by the plurality of projections of the first implant body interlocking with the plurality of projections of the second implant body, each implant body comprising a thermoplastic material, wherein the first and second implant bodies are configured to matingly connect to one another with the rigid plate positioned therebetween, and wherein the combination of the first and second implant bodies and the rigid plate is configured for insertion between the first and second vertebral bodies, and
further comprising a flexible retainer pin for retaining one of the at least one bone screw in a respective fastener bore, the flexible retainer pin positioned through a retaining bore in a portion of the head of the bone screw, wherein a portion of the flexible retainer pin juts out from at least one end of a wall defined by the retaining bore, and wherein the flexible retaining pin is configured to bias toward the head of the bone screw during insertion of the bone screw into the fastener bore, making its effective length less than the diameter of the fastener bore, and bias back to an original position after insertion, thereby retaining the bone screw within the fastener bore.
14. The spinal fusion system of claim 13 , wherein the rigid plate is bisected by a first plane and wherein the longitudinal axis is contained in the first plane.
15. The spinal fusion system of claim 14 , wherein the at least one fastener bore comprises a plurality of fastener bores, and wherein the at least one bone screw comprises a first and second bone screw, the first bone screw being angled upwardly with respect to the first plane and the second bone screw being angled downwardly with respect to the first plane.
16. The spinal fusion system of claim 15 , wherein the first and second bone screws are oppositely disposed at equal angles.
17. The spinal fusion system of claim 16 , wherein the equal angles are between 20 degrees and 45 degrees.
18. The spinal fusion system of claim 17 , wherein the equal angles are 35degrees.
19. The spinal fusion system of claim 13 , wherein the thermoplastic material comprises polyetheretherketone.
20. The spinal fusion system of claim 13 , wherein the first implant body has a first thickness and the second implant body has a second thickness.
21. The spinal fusion system of claim 20 , wherein the first thickness is equal to the second thickness.