Expandable intervertebral implant

• US 9,993,350 B2
• Filed: 01/05/2016
• Issued: 06/12/2018
• Est. Priority Date: 04/05/2008
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Cain, Christopher Marden John
• Primary Examiner(s): Coley, Zade
• Assistant Examiner(s): Chang, Olivia C
• Application Number:
  US14/988,501
• Publication Number:
  US 20160120656A1
• Time in Patent Office: 889 Days
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30537 adjustable
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30601 telescopic
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/4415 elements of the prosthesis being arranged in a chain like manner
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/4485 : comprising three or more adjacent spinal implants
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2220/0091 : connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

An expandable intervertebral implant is provided for insertion into an intervertebral space defined by adjacent vertebrae. The expandable intervertebral implant includes a pair of outer sleeve portions and an inner core disposed between the outer sleeve portions. Movement of the inner core relative to the outer sleeve portions causes the outers sleeve portions to deflect away from each other, thereby engaging the expandable intervertebral implant with the vertebrae and adjusting the height of the intervertebral space.

Claims

1. An intervertebral implant comprising:

an upper portion having an upwardly-facing vertebral engagement surface that is configured to abut an upper vertebra, and an opposed inner surface;

a lower portion having a downwardly-facing vertebral engagement surface that is configured to abut a lower vertebra, and an opposed inner surface;

an inner core longitudinally movable with respect to the upper and lower portions, the inner core including a pair of first sloped engagement surfaces longitudinally spaced from each other in their respective entireties, each of the pair of first sloped engagement surfaces configured to engage a respective engagement surface of the upper portion and a pair of second sloped engagement surfaces longitudinally spaced from each other in their respective entireties, each of the pair of second sloped engagement surfaces configured to engage a respective engagement surface of the lower portion, such that movement of the inner core causes at least one of the upwardly-facing vertebral engagement surface and the downwardly-facing vertebral engagement surface to move away from the other, thereby maintaining an intervertebral space defined by the upper and lower vertebrae at a height,

an actuation member that is engaged with the inner core;

wherein the first sloped engagement surfaces are separated from each other by a structure that extends along a longitudinal length of the inner core;

wherein the first sloped engagement surfaces are parallel to each other and sloped in the same direction, and

wherein the implant is configured to maintain the intervertebral space at the height while the implant is under compressive forces, and while

     1) each of the pair of first sloped engagement surfaces of the inner core are engaged with the respective engagement surface of the upper portion, and

     2) each of the pair of second sloped engagement surfaces of the inner core are engaged with the respective engagement surface of the lower portion.

2. The intervertebral implant of claim 1, wherein;

the inner core is received between the upper portion and the lower portion, and

movement of the inner core causes one of the first sloped engagement surfaces to ride along the engagement surface of the upper portion and cause the upper portion to deflect away from the lower portion, and one of the second sloped engagement surfaces to ride along the engagement surface of the lower portion and cause the lower portion to deflect away from the upper portion, thereby moving the implant to an expanded position.

3. The intervertebral implant of claim 1, wherein the upper portion defines a first opening, and the lower portion defines a second opening.

4. The intervertebral implant of claim 1, wherein the actuation member is configured to move the inner core longitudinally with respect to the upper and lower portions so as to expand the implant along a direction that separates the upwardly-facing vertebral engagement surface and the downwardly-facing vertebral engagement surface to a fully expanded position, whereby when the implant is in the fully expanded position each of the pair of first sloped engagement surfaces remain engaged with the respective engagement surface of the upper portion, and each of the pair of second sloped engagement surfaces remain engaged with the respective engagement surface of the lower portion.

5. An intervertebral implant comprising:

an upper portion having an upwardly-facing vertebral engagement surface and an opposed inner surface;

a lower portion having a downwardly-facing vertebral engagement surface and an opposed inner surface;

an inner core received between the upper portion and the lower portion, the inner core including a pair of first sloped engagement surfaces that are spaced from each other in their respective entireties along a longitudinal direction, one of the pair of first sloped engagement surfaces configured to engage an engagement surface of the upper portion and a pair of second sloped engagement surfaces that are spaced from each other in their respective entireties along the longitudinal direction, one of the pair of second sloped engagement surfaces configured to engage an engagement surface of the lower portion,

an actuation member that is engaged with the inner core and configured to apply a force to the inner core that moves the inner core along the longitudinal direction;

wherein movement of the inner core along the longitudinal direction causes one of the first sloped engagement surfaces to ride along the engagement surface of the upper portion and one of the second sloped engagement surfaces to ride along the engagement surface of the lower portion, thereby moving the implant to an expanded position whereby the upper portion and the lower portion deflect away from each other,

wherein the first sloped engagement surfaces are parallel to each other and parallel to the engagement surface of the upper portion, and the first sloped engagement surfaces are sloped in the same direction as each other and the engagement surface of the upper portion, and

wherein the implant is configured to remain in the expanded position under compressive forces while

     1) the one of the first sloped engagement surfaces engages the engagement surface of the upper portion, and

     2) the one of the second sloped engagement surfaces engages the engagement surface of the lower portion.

6. The intervertebral implant of claim 5, wherein each of the pair of first sloped engagement surfaces is configured to engage a respective engagement surface of the upper portion, and each of the pair of second sloped engagement surfaces is configured to engage a respective engagement surface of the lower portion.

7. The intervertebral implant of claim 6, wherein the first sloped engagement surfaces are connected to each other by a structure that extends along a longitudinal length of the inner core.

8. The intervertebral implant of claim 5, wherein the first sloped engagement surfaces are separated from each other by a structure that extends along a longitudinal length of the inner core.

9. The intervertebral implant of claim 5, wherein movement of the inner core causes one of the first sloped engagement surfaces to push against the engagement surface of the upper portion and one of the second sloped engagement surfaces to push against the engagement surface of the lower portion.

10. The intervertebral implant of claim 7, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

11. The intervertebral implant of claim 8, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

12. The intervertebral implant of claim 9, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

13. The intervertebral implant of claim 5, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

14. The intervertebral implant of claim 5, wherein the ones of the pairs of first and second sloped engagement surfaces remain engaged with the engagement surfaces of the upper and lower portions, respectively, when the implant is in a fully expanded position.

15. An intervertebral implant comprising:

an upper portion having a substantially flat upwardly-facing vertebral engagement surface and an opposed inner surface, wherein the upper portion defines a first groove and teeth that project out from the upwardly-facing vertebral engagement surface;

a lower portion having a substantially flat downwardly-facing vertebral engagement surface and an opposed inner surface, wherein the lower portion defines a second groove and teeth that project out from the upwardly-facing vertebral engagement surface;

an inner core including a first sloped engagement surface and a second sloped engagement surface configured to engage respectively a first engagement surface of the upper portion and a second engagement surface of the upper portion, the inner core further including a third sloped engagement surface and a fourth sloped engagement surface configured to engage respectively a third engagement surface of the lower portion and a fourth engagement surface of the lower portion, wherein movement of the inner core increases a distance between the upwardly-facing vertebral engagement surface and the downwardly-facing vertebral engagement surface so as to move the implant to an expanded position;

an actuation member that is engaged with the inner core and configured to apply a force to the inner core that causes the inner core to move along the longitudinal direction;

wherein the first and second sloped engagement surfaces are connected to each other by a structure that extends along a longitudinal length of the inner core;

wherein the first sloped engagement surface and the second sloped engagement surface are parallel to each other and sloped in the same direction, and the first sloped engagement surface and the second sloped engagement surface are spaced from each other in their respective entireties along the longitudinal direction, and

wherein the implant is configured to remain in the expanded position under compressive forces while

     1) the first and second sloped engagement surfaces of the inner core are engaged with the first and second engagement surfaces of the upper portion, respectively, and

     2) the third and fourth sloped engagement surfaces of the inner core are engaged with the third and fourth engagement surfaces of the lower portion.

16. The intervertebral implant of claim 15, wherein the upper portion defines first and second upper portions that define the first groove therebetween, and the lower portion defines first and second lower portions that define the second groove therebetween.

17. The intervertebral implant of claim 16, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

18. The intervertebral implant of claim 15, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

19. The intervertebral implant of claim 15, wherein

i. the movement of the inner core along the longitudinal direction causes the implant to expand to an expanded position,

ii. when the implant is in a fully expanded position, the first and second sloped engagement surfaces of the inner core remain engaged with the first and second engagement surfaces of the upper portion, respectively, and

iii. when the implant is in the fully expanded position, the third and fourth sloped engagement surfaces of the inner core remain engaged with the third and fourth engagement surfaces of the lower portion, respectively.

20. An intervertebral implant comprising:

an upper portion having an upwardly-facing vertebral engagement surface and an opposed inner surface;

a lower portion having a downwardly-facing vertebral engagement surface and an opposed inner surface, wherein a width of at least one of the upwardly-facing vertebral engagement surface and the downwardly-facing vertebral engagement surface defines a width of the intervertebral implant;

an inner core including a pair of first sloped engagement surfaces longitudinally spaced from each other in their respective entireties, one of the pair of first sloped engagement surfaces configured to engage an engagement surface of the upper portion and a pair of second sloped engagement surfaces longitudinally spaced from each other in their respective entireties, one of the pair of second sloped engagement surfaces configured to engage an engagement surface of the lower portion,

an actuation member that is engaged with the inner core and configured to move the inner core longitudinally so as to cause the ones of the pairs of first and second sloped engagement surfaces to ride along the engagement surfaces of the upper and lower portion, respectively, thereby moving the intervertebral implant to an expanded position whereby a distance between the upwardly-facing vertebral engagement surface and the downwardly-facing vertebral engagement surfaces is increased;

wherein the first sloped engagement surfaces are separated from each other by a structure that extends along a longitudinal length of the inner core;

wherein the first sloped engagement surfaces are parallel to each other and sloped in the same direction, and

wherein the implant is configured to remain in the expanded position under compressive forces while the ones of the pairs of first and second sloped engagement surfaces are engaged with the engagement surfaces of the upper and lower portion.

21. The intervertebral implant of claim 20, wherein movement of the inner core causes one of the pair of first sloped engagement surfaces to ride along the engagement surface of the upper portion and one of the pair of second sloped engagement surfaces to ride along the engagement surface of the lower portion, thereby causing the implant to move to the expanded position whereby the upper portion and the lower portion deflect away from each other.

22. The intervertebral implant of claim 21, wherein the inner core is received between the upper portion and the lower portion.

23. The intervertebral implant of claim 22, wherein movement of the inner core causes the one of the pair of first sloped engagement surfaces to push against the engagement surface of the upper portion, and the one of the pair of second sloped engagement surfaces to push against the engagement surface of the lower portion.

24. The intervertebral implant of claim 22, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

25. The intervertebral implant of claim 24, wherein movement of the biasing member causes translational movement of the inner core.

26. The intervertebral implant of claim 22, wherein each of the pair of first sloped engagement surfaces is configured to engage a respective engagement surface of the upper portion, and each of the pair of second sloped engagement surfaces is configured to engage a respective engagement surface of the lower portion.

27. The intervertebral implant of claim 26, wherein the inner core comprises:

a plurality of first sloped engagement surfaces, each of the plurality of first sloped engagement surfaces configured to engage an engagement surface of the upper portion; and

a plurality of second sloped engagement surfaces, each of the plurality of second sloped engagement surfaces configured to engage an engagement surface of the lower portion.

28. The intervertebral implant of claim 20, wherein the upper portion defines a first groove, and the lower portion defines a second groove.

29. The intervertebral implant of claim 28, wherein the upper portion defines first and second upper portions that define the first groove therebetween, and the lower portion defines first and second lower portions that define the second groove therebetween.

30. The intervertebral implant of claim 29, wherein,

one of the pair of first sloped engagement surfaces is configured to engage the engagement surface of the upper portion,

another of the pair of first sloped engagement surfaces is configured to engage a second engagement surface of the upper portion,

one of the pair of second sloped engagement surfaces is configured to engage the engagement surface of the lower portion, and

another of the pair of second sloped engagement surfaces is configured to engage a second engagement surface of the lower portion.

31. The intervertebral implant of claim 30, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

32. The intervertebral implant of claim 28, wherein,

one of the pair of first sloped engagement surfaces is configured to engage the engagement surface of the upper portion,

another of the pair of first sloped engagement surfaces is configured to engage a second engagement surface of the upper portion,

one of the pair of second sloped engagement surfaces is configured to engage the engagement surface of the lower portion, and

another of the pair of second sloped engagement surfaces is configured to engage a second engagement surface of the lower portion.

33. The intervertebral implant of claim 32, wherein the actuation member comprises a biasing member that is in abutment with the inner core.

34. The intervertebral implant of claim 20, wherein the ones of the pairs of first and second sloped engagement surfaces remain engaged with the engagement surfaces of the upper and lower portions, respectively, when the implant is in a fully expanded position.