Wave spring for a spinal implant
A spinal implant includes a wave spring configured to surround a nucleus. The spring may be formed from a shape memory material. The implant may further include an artificial nucleus configured to simulate a disc nucleus.
1. A spinal implant comprising:
a coiled wave spring configured to surround a nucleus, wherein the wave spring is formed with at least one wire having a sinusoidal shape and made of a shape memory material, wherein the shape memory material is tailored to achieve a stress-induced martensitic transformation when a critical stress is exceeded and the shape memory material is further trained to expand to a preset shape when the wave spring temperature exceeds its transition temperature.
2. The spinal implant according to claim 1 , wherein the wave spring is wedge shaped.
3. The spinal implant according to claim 1 , wherein the shape memory material is selected from the group consisting of Nitinol, a Titanium-Niobium alloy, and combinations thereof.
4. The spinal implant according to claim 1 , wherein the wave spring is formed with one or more flat wires.
5. The spinal implant according to claim 1 , wherein the wave spring is formed with one or more rectangular wires.
6. The spinal implant according to claim 1 , further comprising:
an artificial nucleus configured to simulate a disc nucleus, wherein the wave spring surrounds the artificial nucleus.
7. The spinal implant according to claim 6 , wherein the artificial nucleus is made from a polymer material.
8. The spinal implant according to claim 6 , wherein the artificial nucleus is made from a hydro-gel material.
9. The spinal implant according to claim 6 , wherein the artificial nucleus is a wave spring.
10. A method of forming a spinal implant, the method comprising:
forming a coiled wave spring, the wave spring having at least one wire with a sinusoidal shape and made of a shape memory material, wherein the shape memory material is tailored to achieve a stress-induced martensitic transformation when a critical stress is exceeded and the shape memory material is further trained to expand to a preset shape when the wave spring temperature exceeds its transition temperature; and
configuring the wave spring to surrounding a nucleus.
11. The method according to claim 10 , wherein the wave spring is wedge shaped.
12. The method according to claim 10 , wherein the shape memory material is selected from the group consisting of Nitinol, a Titanium-Niobium alloy, and combinations thereof.
13. The method according to claim 10 , wherein the wave spring is formed with one or more flat wires.
14. The method according to claim 10 , wherein the wave spring is formed with one or more rectangular wires.
15. The method according to claim 10 , further comprising
forming an artificial nucleus configured to simulate a disc nucleus, wherein the wave spring surrounds the artificial nucleus.
16. The method according to claim 15 , wherein the artificial nucleus is formed from a polymer material.
17. The method according to claim 15 , wherein the artificial nucleus is formed from a hydro-gel material.
18. The method according to claim 15 , wherein the artificial nucleus is formed from a wave spring.
19. A method of implanting a spinal implant, the method comprising:
inserting a coiled wave spring into an intervertebral space, wherein the wave spring is formed with at least one wire having a sinusoidal shape and made of a shape memory material, wherein the shape memory material is tailored to achieve a stress-induced martensitic transformation when a critical stress is exceeded and the shape memory material is further trained to expand to a preset shape when the wave spring temperature exceeds its transition temperature; and
introducing a nucleus material into an interior area of the wave spring, the nucleus material configured to simulate a disc nucleus.
20. A method of forming a spinal implant, the method comprising:
providing a shape memory material with about 30-40% cold work;
coiling a wave spring, the wave spring having at least one wire with a sinusoidal shape and made of the shape memory material, wherein the shape memory material is tailored to achieve a stress-induced martensitic transformation when a critical stress is exceeded; and
subsequently age heat treating the shape memory material after coiling the wave spring.