Expandable intervertebral implant and associated instrumentation

• US 20060247770A1
• Filed: 04/29/2005
• Published: 11/02/2006
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Peterman, Marc M.
• Granted Patent: US 7,749,270 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• 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 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• 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 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30828 parallel
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30892 parallel
• 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 2002/4627 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 2002/4629 connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2310/00017 Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures

Abstract

An expandable intervertebral implant including an implant body transitionable between an initial configuration and an expanded configuration, and having first and second axial walls spaced apart along a transverse axis with at least one of the walls defining a recessed region when the implant body is in the initial configuration. An expansion member co-acts with the axial wall to transition the implant body to the expanded configuration wherein the recessed region is outwardly expanded generally along the transverse axis. In another embodiment, the expansion member includes a first portion that is displaced along an axially extending slot formed in one of the walls, and a second portion that is displaced between the walls to transition the implant body to the expanded configuration. In a further embodiment, the first portion of the expansion member defines a passage extending therethrough having an inner transverse dimension sized larger than an outer transverse dimension of the second portion.

Claims

1. An expandable intervertebral implant, comprising:

an implant body having a longitudinal axis and being transitionable between an initial configuration and an expanded configuration, said implant body including first and second axial walls spaced apart along a transverse axis, at least one of said axial walls defining a recessed region when said implant body is in said initial configuration; and

an expansion member co-acting with said at least one of said axial walls to transition said implant body from said initial configuration to said expanded configuration wherein said recessed region is outwardly expanded generally along said transverse axis.

2. The implant of claim 1, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall.

3. The implant of claim 2, wherein said recessed region comprises a concave curvature extending inwardly along said transverse axis.

4. The implant of claim 3, wherein said concave curvature extends along substantially an entire length of said at least one of said axial walls between said pair of opposite end portions.

5. The implant of claim 2, wherein said implant body has a first outer transverse dimension adjacent one of said end walls, said implant body having a second outer transverse dimension adjacent said recessed region when said implant body is in said initial configuration;

and

wherein said second outer transverse dimension is less than said first outer transverse dimension.

6. The implant of claim 2, wherein said at least one of said axial walls includes a number of surface protrusions projecting outwardly from said recessed region.

7. The implant of claim 6, wherein said opposite end portions of said at least one of said axial walls are positioned along a plane, said surface protrusions at least partially positioned inward of said plane when said implant body is in said initial configuration.

8. The implant of claim 7, wherein said surface protrusions comprise teeth adapted for engagement with vertebral bone.

9. The implant of claim 7, wherein said surface protrusions are positioned entirely inward of said plane when said implant body is in said initial configuration.

10. The implant of claim 6, wherein said surface protrusions are confined to a central portion of said implant body.

11. The implant of claim 1, wherein said recessed region is defined along substantially an entire length of said implant body.

12. The implant of claim 1, wherein said recessed region comprises a concave curvature extending inwardly along said transverse axis and along substantially an entire length of said implant body.

13. The implant of claim 12, wherein said at least one of said axial walls has a posterior end portion and an anterior end portion, said recessed region comprises a concave curvature extending inwardly along said transverse axis between said posterior and anterior end portions.

14. The implant of claim 1, wherein said at least one of said axial walls has opposite first and second end portions arranged along said longitudinal axis, said at least one of said axial walls including a number of surface protrusions projecting outwardly from said recessed region;

and

wherein said opposite first and second end portions of said at least one of said axial walls are positioned along a plane, said surface protrusions at least partially positioned inward of said plane when said implant body is in said initial configuration.

15. The implant of claim 14, wherein said surface protrusions are positioned entirely inward of said plane when said implant body is in said initial configuration.

16. The implant of claim 1, wherein said recessed region of said at least one of said axial walls defines a convex curvature extending outwardly along said transverse axis when said implant body is transitioned to said expanded configuration.

17. The implant of claim 1, wherein each of said first and second axial walls defines a recessed region when said implant body is in said initial configuration, said expansion member co-acting with said first and second axial walls to transition said implant body from said initial configuration to said expanded configuration wherein each of said recessed regions are outwardly expanded generally along said transverse axis.

18. The implant of claim 17, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall, said recessed regions positioned between said opposite end portions of said first and second axial walls.

19. The implant of claim 17, wherein said each of said recessed regions comprises a concave curvature extending inwardly along said transverse axis and along substantially an entire length of said implant body.

20. The implant of claim 1, wherein said at least one of said axial walls is flexibly deformed during transitioning of said implant body to said expanded configuration to outwardly expand said recessed region generally along said transverse axis.

21. The implant of claim 1, wherein said implant body defines an inner chamber sized to receive said expansion member therein;

and

wherein axial movement of said expansion member within said inner chamber transitions said implant body to said expanded configuration.

22. The implant of claim 21, wherein said first and second axial walls have inner surfaces facing said inner chamber, at least one of said inner surfaces defining an inward taper along said longitudinal axis, said expansion member slidably engaging said inward taper during said axial movement to transition said implant body toward said expanded configuration.

23. The implant of claim 1, wherein said implant body defines an inner fusion chamber, each of said first and second axial walls defining at least one bone in-growth opening extending therethrough and communicating with said inner fusion chamber;

and

further comprising a bone growth promoting substance positioned within said inner chamber to facilitate fusion with adjacent vertebral bodies.

24. The implant of claim 23, wherein said bone growth promoting substance comprises a bone morphogenic protein.

25. An expandable intervertebral implant, comprising:

an implant body having a longitudinal axis and being transitionable between an initial configuration and an expanded configuration, said implant body including first and second axial walls spaced apart along a transverse axis, at least one of said axial walls defining a slot having a length extending generally along said longitudinal axis; and

an expansion member including a first portion positioned within said slot and a second portion positioned between said axial walls such that axial movement of said expansion member generally along said longitudinal axis displaces said first portion along said length of said slot and displaces said second portion between said axial walls to transition said implant body from said initial configuration to said expanded configuration wherein at least one of said axial walls is outwardly expanded generally along said transverse axis.

26. The implant of claim 25, wherein said expansion member includes a pair of said second portions extending in generally opposite directions relative to said first portion, each of said second portions at least partially positioned between said axial walls such that axial movement of said expansion member generally along said longitudinal axis displaces said second portions between said axial walls to transition said implant body from said initial configuration to said expanded configuration.

27. The implant of claim 25, wherein said first portion of said expansion member is sized for sliding engagement along opposing side surfaces of said slot to guide said expansion member generally along said longitudinal axis during said axial movement.

28. The implant of claim 25, wherein each of said first and second axial walls defines a slot having a length extending generally along said longitudinal axis, said first portion of said expansion member including a first segment positioned within said slot in said first axial wall and a second segment positioned within said slot in said second axial wall.

29. The implant of claim 28, wherein said first and second segments of said first portion of said expansion member are sized in relatively close tolerance with said slots in said first and second axial walls.

30. The implant of claim 25, wherein said first portion of said expansion member defines a passage extending therethrough having an inner transverse dimension sized larger than an outer transverse dimension of said second portion.

31. The implant of claim 25, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall.

32. The implant of claim 25, wherein said first and second axial walls include opposing inner surfaces, at least one of said inner surfaces defining an inward taper along said longitudinal axis, said second portion of said expansion member being displaced between said inner surfaces and slidably engaged along said inward taper during said axial movement of said expansion member to transition said implant body toward said expanded configuration.

33. The implant of claim 25, wherein said implant body defines an inner fusion chamber, each of said first and second axial walls defining at least one bone in-growth opening extending therethrough and communicating with said inner fusion chamber;

and

further comprising a bone growth promoting substance positioned within said inner chamber to facilitate fusion with adjacent vertebral bodies.

34. The implant of claim 33, wherein said expansion member is positioned within a central portion of said inner chamber to transition said implant body to said expanded configuration, said bone growth promoting substance positioned within first and second end portions of said inner chamber on opposite sides of said expansion member, said expansion member defining a passage extending therethrough, said bone growth promoting substance conveyed through said passage and into one of said first and second end portions of said inner chamber.

35. The implant of claim 34, wherein said passage extending through said expansion member has an inner transverse dimension sized larger than an outer transverse dimension of said second portion of said expansion member.

36. The implant of claim 25, wherein at least one of said axial walls defines a recessed region when said implant body is in said initial configuration;

and

wherein said recessed region is outwardly expanded generally along said transverse axis as said implant body is transitioned to said expanded configuration.

37. The implant of claim 36, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall, said recessed region extending along substantially an entire length of said at least one of said axial walls between said pair of opposite end portions.

38. The implant of claim 37, wherein said recessed region comprises a concave curvature extending along substantially an entire length of said at least one of said axial walls between said pair of opposite end portions.

39. The implant of claim 38, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall, said at least one of said axial walls including a number of surface protrusions projecting outwardly from said recessed region, said opposite end portions of said at least one of said axial walls positioned along a plane, said surface protrusions at least partially positioned inward of said plane when said implant body is in said initial configuration.

40. An expandable intervertebral implant, comprising:

an implant body having a longitudinal axis and being transitionable between an initial configuration and an expanded configuration, said implant body including first and second axial walls spaced apart along a transverse axis; and

an expansion member including a body portion and at least one side portion, said at least one side portion at least partially positioned between said axial walls such that movement of said expansion member generally along said longitudinal axis displaces said side portion between said axial walls to transition said implant body from said initial configuration to said expanded configuration wherein at least one of said axial walls is outwardly expanded generally along said transverse axis, said body portion defining a passage extending therethrough having an inner transverse dimension sized larger than an outer transverse dimension of said at least one side portion.

41. The implant of claim 40, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall.

42. The implant of claim 40, wherein said first and second axial walls include opposing inner surfaces, at least one of said inner surfaces defining an inward taper along said longitudinal axis, said at least one side portion of said expansion member being displaced between said inner surfaces and slidably engaged along said inward taper during said axial movement of said expansion member to transition said implant body toward said expanded configuration.

43. The implant of claim 40, wherein said implant body defines an inner fusion chamber, each of said first and second axial walls defining at least one bone in-growth opening extending therethrough and communicating with said inner fusion chamber;

and

further comprising a bone growth promoting substance positioned within said inner chamber to facilitate fusion with adjacent vertebral bodies.

44. The implant of claim 43, wherein said expansion member is positioned within a central portion of said inner chamber to transition said implant body to said expanded configuration, said bone growth promoting substance positioned within first and second end portions of said inner chamber on opposite sides of said expansion member, said body portion of said expansion member defining a passage extending therethrough, said bone growth promoting substance conveyed through said passage and into one of said first and second end portions of said inner chamber.

45. The implant of claim 40, wherein said passage has a generally circular shape defining a first diameter, said at least one side portion of said expansion member having a generally circular outer cross section defining a second diameter, said first diameter of said passage sized larger than said second diameter of said at least one side portion of said expansion member.

46. The implant of claim 40, wherein said expansion member includes a pair of said side portions extending in generally opposite directions relative to said body portion, each of said side portions at least partially positioned between said axial walls such that axial movement of said expansion member generally along said longitudinal axis displaces said side portions between said axial walls to transition said implant body from said initial configuration to said expanded configuration.

47. The implant of claim 40, wherein at least one of said axial walls defines a slot having a length extending generally along said longitudinal axis, said body portion of said expansion member including a segment positioned within said slot such that said axial movement of said expansion member displaces said segment along said length of said slot.

48. The implant of claim 47, wherein said segment of said body portion is sized for sliding engagement along opposing side surfaces of said slot to guide said expansion member generally along said longitudinal axis during said axial movement.

49. The implant of claim 40, wherein each of said first and second axial walls defines a slot having a length extending generally along said longitudinal axis, said body portion of said expansion member including a first segment positioned within said slot in said first axial wall and a second segment positioned within said slot in said second axial wall, each of said first and second segments of said body portion sized in relatively close tolerance with said slots in said first and second axial walls.

50. The implant of claim 40, wherein at least one of said axial walls defines a recessed region when said implant body is in said initial configuration;

and

wherein said recessed region is outwardly expanded generally along said transverse axis as said implant body is transitioned to said expanded configuration.

51. The implant of claim 50, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall, said recessed region extending along substantially an entire length of said at least one of said axial walls between said pair of opposite end portions.

52. The implant of claim 50, wherein said implant body includes first and second transverse end walls interconnecting opposite end portions of said first axial wall with opposite end portions of said second axial wall, said at least one of said axial walls including a number of surface protrusions projecting outwardly from said recessed region, said opposite end portions of said at least one of said axial walls positioned along a plane, said surface protrusions at least partially positioned inward of said plane when said implant body is in said initial configuration.