Artificial spinal discs and methods
View Patent ↗An artificial disc includes a top vertebra-attachment portion and a lower spacer support connected to the top vertebra-attachment portion; a bottom vertebra-attachment portion and an upper spacer support connected to the bottom vertebra-attachment portion. The spacer supports are disposed between the vertebra-attachment portions, and the lower spacer support is disposed between the bottom vertebra-attachment portion and the upper spacer support. The disc further includes a first elastic spacer positioned between the spacer supports for compressively resisting tensile loading of the disc; and a second spacer disposed between the bottom vertebra-attachment portion and the lower spacer support or between the top vertebra-attachment portion and the upper spacer support for compressively resisting compressive loading of the disc.
1. An artificial spinal disc for implantation within a disc space between first and second opposing vertebrae, comprising:
a first member having a first vertebra-attachment plate for attaching to the first vertebra within the disc space and a first spacer support connected to the first vertebra-attachment plate;
a second member having a second vertebra-attachment plate for attaching to the second opposing vertebra within the disc space and a second spacer support connected to the second vertebra-attachment plate, the spacer supports being disposed between the vertebra-attachment plates, and the first spacer support being disposed between the second vertebra-attachment plate and the second spacer support; and
a first elastic spacer positioned between the spacer supports,
whereby the spacer supports compress the first elastic spacer when the vertebra-attachment plates are biased away from each other.
2. The artificial spinal disc of claim 1 , further comprising a second elastic spacer, positioned between the first vertebra-attachment plate and the second spacer support.
3. The artificial disc of claim 2 , further comprising a third elastic spacer, positioned between the second vertebra-attachment plate and the first spacer support.
4. The artificial disc of claim 1 , further comprising an elastic spacer extending from the first vertebra-attachment plate to the second vertebra-attachment plate.
5. The artificial disc of claim 1 , wherein the first elastic spacer comprises a thermoplastic elastomer or a hydrogel.
6. The artificial disc of claim 1 , wherein the first elastic spacer comprises a metal spring.
7. The artificial disc of claim 1 , wherein the first spacer support is connected to the first vertebra-attachment plate by a post, and the first elastic spacer surrounds the post.
8. The artificial disc of claim 1 , further comprising means for pre-compressing the artificial disc.
9. The artificial disc of claim 1 , wherein the first member and the second member are interlocked with one another.
10. An artificial spinal disc for implantation within a disc space between first and second opposing vertebrae, comprising:
a first member having a first vertebra-attachment plate for attaching to the first vertebra within the disc space and a first spacer support connected to the first vertebra-attachment plate;
a second member having a second vertebra-attachment plate for attaching to the second opposing vertebra within the disc space and a second spacer support connected to the second vertebra-attachment plate, the spacer supports being disposed between the vertebra-attachment plates, and the first spacer support being disposed between the second vertebra-attachment plate and the second spacer support; and
a first elastic spacer positioned between the first vertebra-attachment plate and the second spacer support,
whereby the spacer supports compress the first elastic spacer when the vertebra-attachment plate are biased away-from toward each other.
11. The artificial spinal disc of claim 10 , further comprising a second elastic spacer, positioned between the spacer supports.
12. The artificial spinal disc of claim 11 , further comprising a third elastic spacer, positioned between the second vertebra-attachment plate and the first spacer support.
13. The artificial spinal disc of claim 10 , further comprising an elastic spacer extending from the first vertebra-attachment plate to the second vertebra-attachment plate.
14. The artificial spinal disc of claim 10 , wherein the first elastic spacer comprises a thermoplastic elastomer or a hydrogel.
15. The artificial spinal disc of claim 10 , wherein the first elastic spacer comprises a metal spring.
16. The artificial disc of claim 10 , wherein the first spacer support is connected to the first vertebra-attachment plate by a post, and the first elastic spacer surrounds the post.
17. A method of implanting an artificial spinal disc, the method comprising the steps of:
removing at least a portion of a natural spinal disc from between first and second adjacent vertebral bodies;
positioning an artificial spinal disc between the first and second vertebral bodies within the disc space, the artificial spinal disc comprising:
a first member having a first vertebra-attachment plate and a first spacer support connected to the first vertebra-attachment plate;
a second member having a second vertebra-attachment plate and a second spacer support connected to the second vertebra-attachment plate, the spacer supports being disposed between the vertebra-attachment plates, and the first spacer support being disposed between the second vertebra-attachment plate and the second spacer support; and
a first elastic spacer positioned between the spacer supports;
securing the first vertebra-attachment portion to the first vertebra; and
securing the second vertebra-attachment portion to the second vertebra.
18. The method of claim 17 , wherein the artificial disc further comprises a second elastic spacer, positioned between the first vertebra-attachment plate and the second spacer support.
19. The method of claim 18 , further comprising compressing the first elastic spacer by tensilely loading the artificial spinal disc; and compressing the second elastic spacer by compressively loading the artificial spinal disc.
20. The method of claim 18 , further comprising pre-compressing the second elastic spacer by compressively loading the artificial spinal disc prior to positioning the artificial disc between the first and second vertebral bodies.