Intervertebral disc implants and methods for manufacturing and using the same
Described are intervertebral disc implants that include an elastomeric polymer body, especially a hydrogel body, and a superelastic element. Also described are methods for making and using such implants.
1. An intervertebral disc implant, comprising:
an elastomeric polymer body sized for introduction into a disc space; and
a superelastic element within the elastomeric body, the superelastic element comprising a superelastic metal alloy having shape-memory properties; and
wherein each of said elastomeric polymer body and said superelastic element are elongate and each have a generally linear and substantially straight insertion configuration that is transitioned to an implanted configuration upon introduction into the disc space, said implanted configuration comprising a coiled configuration having a spiral shape; and
wherein said coiled configuration includes multiple coils spiraling about a center of the implant, and wherein a central region of the implant in said coiled configuration is substantially solid; and
wherein said shape-memory properties of said superelastic element forcibly maintains adjacent ones of said multiple coils in contact with one another by a residual force to thereby stabilize said coiled configuration of the implant.
2. The intervertebral disc implant of claim 1 , wherein the elastomeric polymer body is water-swellable.
3. The intervertebral disc implant of claim 2 , wherein the elastomeric polymer body comprises a hydrogel.
4. The intervertebral disc implant of claim 1 , wherein said elastomeric polymer body comprises a water-swellable material that is dehydrated or partially hydrated when the implant is in said insertion configuration, said elastomeric polymer body having a first volume when the implant is in said insertion configuration; and
wherein said water-swellable material has increased hydration when the implant is transitioned to said implanted configuration within the disc space, said elastomeric polymer body having a second volume in said implanted configuration that is larger than said first volume in said insertion configuration.
5. The intervertebral disc implant of claim 1 , wherein said coiled configuration includes at least three of said coils that each spiral a full 360 degrees about said center of the implant.
6. The intervertebral disc implant of claim 5 , wherein said coiled configuration includes four of said coils that each spiral a full 360 degrees about said center of the implant.
7. An intervertebral disc implant, comprising:
an outer element formed of an elastomeric material; and
an inner core element formed of a shape-memory material comprising a superelastic metal alloy having shape-memory properties, said inner core element embedded within said elastomeric material of said outer element; and
wherein the implant has an insertion configuration sized and shaped for introduction into an intervertebral disc space with each of said outer element and said inner core element having a generally linear and substantially straight configuration when said implant is in said insertion configuration; and
wherein the implant is transitioned from said insertion configuration to a different implanted configuration upon introduction into the intervertebral disc space, said implanted configuration comprising a coiled configuration having a spiral shape; and
wherein said coiled configuration includes multiple coils spiraling about a center of the implant, and wherein a central region of the implant in said coiled configuration is substantially solid; and
wherein said shape-memory properties of said inner core element forcibly maintains adjacent ones of said multiple coils in contact with one another by a residual force to thereby stabilize said coiled configuration of the implant.
8. The intervertebral disc implant of claim 7 , wherein said elastomeric material comprises a water-swellable material that is dehydrated or partially hydrated when the implant is in said insertion configuration, said outer element having a first cross-sectional dimension when the implant is in said insertion configuration; and
wherein said water-swellable material has increased hydration when the implant is transitioned to said implanted configuration within the intervertebral disc space, said outer element having a second cross-sectional dimension in said implanted configuration that is larger than said first cross-sectional dimension in said insertion configuration.
9. The intervertebral disc implant of claim 8 , wherein said water-swellable material comprises a hydrogel material.
10. The intervertebral disc implant of claim 7 , wherein said elastomeric material comprises a polymeric material.
11. The intervertebral disc implant of claim 10 , wherein said polymeric material comprises a hydrogel material.
12. The intervertebral disc implant of claim 7 , wherein said shape-memory material exhibits superelastic characteristics; and
wherein the implant is transitioned from an initial configuration to said insertion configuration upon imposition of stress onto the implant; and
wherein the implant is automatically transitioned from said insertion configuration to said implanted configuration without a corresponding change in temperature upon removal of said stress on the implant.
13. The intervertebral disc implant of claim 12 , wherein said initial configuration comprises a first coiled configuration; and
wherein the implant is transitioned from said first coiled configuration to a generally linear and substantially straight configuration defining said insertion configuration upon imposition of said stress onto the implant; and
wherein the implant is transitioned from said generally linear and substantially straight configuration to a second coiled configuration defining said implanted configuration upon removal of said stress on the implant.
14. The intervertebral disc implant of claim 7 , wherein said shape-memory material is transitioned from said insertion configuration to said implanted configuration in response to a corresponding change in temperature upon insertion into the intervertebral disc space.
15. The intervertebral disc implant of claim 7 , wherein said elastomeric material comprises a water-swellable material that is dehydrated or partially hydrated when the implant is in said insertion configuration, said outer element having a first volume when the implant is in said insertion configuration; and
wherein said water-swellable material has increased hydration when the implant is transitioned to said implanted configuration within the intervertebral disc space, said outer element having a second volume in said implanted configuration that is larger than said first volume in said insertion configuration.
16. The intervertebral disc implant of claim 7 , wherein said coiled configuration includes at least three of said coils that each spiral a full 360 degrees about said center of the implant.
17. The intervertebral disc implant of claim 16 , wherein said coiled configuration includes four of said coils that each spiral a full 360 degrees about said center of the implant.
18. An intervertebral disc implant, comprising:
an outer element formed of an elastomeric hydrogel material; and
an inner core element formed of a shape-memory material having shape-memory properties, said inner core element embedded within said elastomeric hydrogel material of said outer element; and
wherein the implant has an insertion configuration sized and shaped for introduction into an intervertebral disc space, said elastomeric hydrogel material being dehydrated or partially hydrated when the implant is in said insertion configuration to provide said outer element with a first cross-sectional dimension;
wherein the implant is transitioned from said insertion configuration to a different implanted configuration upon introduction into the intervertebral disc space, said elastomeric hydrogel material having increased hydration when the implant is transitioned to said implanted configuration within the intervertebral disc space to provide said outer element with a second cross-sectional dimension larger than said first cross-sectional dimension; and
wherein said insertion configuration comprises a generally linear and substantially straight configuration with each of said outer element and said inner core element being generally linear and substantially straight when said implant is in said insertion configuration; and
wherein said implanted configuration comprises a coiled configuration with each of said outer element and said inner core element having a spiral shape when said implant is in said coiled configuration; and
wherein said coiled configuration includes multiple coils spiraling about a center of the implant, and wherein a central region of the implant in said coiled configuration is substantially solid; and
wherein said shape-memory properties of said inner core element forcibly maintains adjacent ones of said multiple coils in contact with one another by a residual force to thereby stabilize said coiled configuration of the implant.
19. The intervertebral disc implant of claim 18 , wherein said shape-memory material exhibits superelastic characteristics; and
wherein the implant is transitioned from an initial configuration to said insertion configuration upon imposition of stress onto the implant; and
wherein the implant is automatically transitioned from said insertion configuration to said implanted configuration upon removal of said stress on the implant.
20. The intervertebral disc implant of claim 19 , wherein said initial configuration comprises a first coiled configuration; and
wherein the implant is transitioned from said first coiled configuration to said generally linear and substantially straight configuration defining said insertion configuration upon imposition of said stress onto the implant; and
wherein the implant is transitioned from said generally linear and substantially straight configuration to a second coiled configuration defining said implanted configuration upon removal of said stress on the implant.
21. The intervertebral disc implant of claim 18 , wherein said shape-memory material is transitioned from said insertion configuration to said implanted configuration in response to a corresponding change in temperature upon insertion into the intervertebral disc space; and
wherein said substantially straight configuration is transitioned to said coiled configuration defining said implanted configuration upon said corresponding change in temperature.
22. The intervertebral disc implant of claim 18 , wherein said coiled configuration includes at least three of said coils that each spiral a full 360 degrees about said center of the implant.
23. The intervertebral disc implant of claim 22 , wherein said coiled configuration includes four of said coils that each spiral a full 360 degrees about said center of the implant.
24. An intervertebral disc implant, comprising:
an outer element formed of an elastomeric hydrogel material; and
an inner core element formed of a shape-memory material, said inner core element embedded within said elastomeric hydrogel material of said outer element; and
wherein the implant has an insertion configuration sized and shaped for introduction into an intervertebral disc space. said elastomeric hydrogel material being dehydrated or partially hydrated when the implant is in said insertion configuration to provide said outer element with a first cross-sectional dimension;
wherein the implant is transitioned from said insertion configuration to a different implanted configuration upon introduction into the intervertebral disc space, said elastomeric hydrogel material having increased hydration when the implant is transitioned to said implanted configuration within the intervertebral disc space to provide said outer element with a second cross-sectional dimension larger than said first cross-sectional dimension; and
wherein said insertion configuration comprises a generally linear and substantially straight configuration with each of said outer element and said inner core element being generally linear and substantially straight when said implant is in said insertion configuration; and
wherein said implanted configuration comprises a coiled configuration with each of said outer element and said inner core element having a spiral shape when said implant is in said coiled configuration; and
wherein said coiled configuration includes multiple coils spiraling about a center of the implant, and wherein a central region of the implant in said coiled configuration is substantially solid; and
wherein said outer element has a first volume when the implant is in said insertion configuration, said outer element having a second volume in said implanted configuration that is larger than said first volume.
25. The intervertebral disc implant of claim 24 , wherein said shape-memory material has shape-memory properties; and
wherein said shape-memory properties of said inner core element forcibly maintains adjacent ones of said multiple coils in contact with one another by a residual force to thereby stabilize said coiled configuration of the implant.