Expandable intervertebral implant

• US 7,753,958 B2
• Filed: 02/03/2005
• Issued: 07/13/2010
• Est. Priority Date: 08/05/2003
• Status: Expired due to Fees

• Current Assignee: Flexuspine
• Original Assignee: Flexuspine
• Inventors: Gordon, Charles R., Hanson, Heather S., Harbold, Corey T.
• Primary Examiner(s): McDermott; Corrine M
• Assistant Examiner(s): Prone; Christopher D
• Application Number:
  US11/050,632
• Publication Number:
  US 20050209698A1
• Time in Patent Office: 1,986 Days
• Field of Search: 623/17.15
• US Class Current: 623/17.15
• CPC Class Codes: A61B 17/7005 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit in the screw or hook heads
• CPC Class Codes: A61B 17/7007 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• CPC Class Codes: A61B 17/7008 with parts of, or attached to, the longitudinal elements, bearing against an outside of the screw or hook heads, e.g. nuts on threaded rods A61B17/7007 takes precedence
• CPC Class Codes: A61B 17/701 Longitudinal elements with a non-circular, e.g. rectangular, cross-section A61B17/7005, A61B17/7007 take precedence
• CPC Class Codes: A61B 17/7023 with a pivot joint
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7037 wherein pivoting is blocked when the rod is clamped
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• 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 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• CPC Class Codes: A61F 2002/3023 : wedge-shaped cylinders
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30331 : made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30365 : with additional means for limiting said rotation
• CPC Class Codes: A61F 2002/30369 : Limited lateral translation of the protrusion within a larger recess
• CPC Class Codes: A61F 2002/30383 : made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• 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 2002/30476 : locked by an additional locking mechanism
• CPC Class Codes: A61F 2002/30492 : using a locking pin
• CPC Class Codes: A61F 2002/305 : Snap connection
• CPC Class Codes: A61F 2002/30505 : spring biased
• CPC Class Codes: A61F 2002/30507 : using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30515 : using a locking wedge or block
• CPC Class Codes: A61F 2002/3052 : unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30538 : for adjusting angular orientation
• CPC Class Codes: A61F 2002/3055 : for adjusting length
• CPC Class Codes: A61F 2002/30556 : for adjusting thickness
• CPC Class Codes: A61F 2002/30563 : having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30565 : having spring elements
• CPC Class Codes: A61F 2002/30578 : having apertures, e.g. for receiving fixation screws
• 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 2002/30624 : Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/30649 : Ball-and-socket joints
• CPC Class Codes: A61F 2002/30662 : with rotation-limiting means
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/4622 : having the shape of a forceps or a clamp
• 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 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• 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 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

An expandable intervertebral implant for insertion between vertebrae of a human spine is described. The intervertebral implant includes an upper body that engages a first vertebra of the human spine, a lower body that engages a second vertebra of the human spine, an insert, and an advancing element. The advancing element may engage the insert such that advancement of the advancing element causes the insert to at least partially rotate between the upper body and the lower body. Rotation of the insert may cause the insert to interact with at least a portion of the upper body or at least a portion of the lower body to increase a separation distance between the upper body and the lower body, thereby increasing a height of the intervertebral implant after insertion of the implant between the first vertebra and the second vertebra of the human spine.

Claims

1. An intervertebral implant for a human spine, comprising:

an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;

a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;

an insert configured to be positioned between the inferior surface of the upper body and the superior surface of the lower body, wherein the insert is configured to rotate about an axis of rotation, wherein the insert comprises one or more projections comprising a substantially planar surface that is substantially parallel to the axis of rotation and wherein the substantially planar surface extends from an exterior surface of the insert in a radial direction with respect to the axis of rotation of the insert; and

an advancing element configured such that advancement of the advancing element causes at least a portion of the advancing element to engage the substantially flat planar surface of at least one of the one or more projections to at least partially rotate the insert to increase a separation distance between the upper body and the lower body, thereby increasing a height of the intervertebral implant after insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine.

2. The intervertebral implant of claim 1, wherein the insert engages at least a portion of the upper body or at least a portion of the lower body to increase the separation distance between the upper body and the lower body.

3. The intervertebral implant of claim 1, wherein the advancing element is further configured to engage the insert after insertion of the implant between the first vertebra and the second vertebra of the human spine.

4. The intervertebral implant of claim 1, wherein the advancing element is configured to rotate about a longitudinal axis of the advancing element that is substantially perpendicular to and offset from the axis of rotation.

5. The intervertebral implant of claim 1, wherein at least a portion of the upper body is configured to contact at least a portion of the lower body before advancement of the advancing element.

6. The intervertebral implant of claim 1, wherein the advancing element comprises a tapered portion, and wherein the tapered portion of the advancing element is configured to engage the insert.

7. The intervertebral implant of claim 1, wherein the insert comprises a cylindrical portion, and wherein at least one of the one or more projections comprises an arm that extends radially from a circumference of the cylindrical portion.

8. The intervertebral implant of claim 1, wherein a portion of the upper body or the lower body that interacts with the insert comprises one or more cam ramps, wherein rotation of the insert by the advancing element causes at least one of the projections of the insert to travel along at least a portion of at least one of the cam ramps, thereby increasing a separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

9. The intervertebral implant of claim 1, wherein a portion of the upper body or the lower body that interacts with the insert comprises one or more cam ramps, and wherein rotation of the insert by the advancing element causes at least one of the projections of the insert to travel along at least a portion of at least one of the cam ramps, wherein the insert is configured to be rotated until an inferior surface of at least one of the cam ramps or a superior surface of at least one of the cam ramps rests on a superior surface of at least one of the projections of the insert or an inferior surface of at least one of the projections of the insert, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

10. The intervertebral implant of claim 1, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more extensions, wherein the insert comprises at least one cam ramp, wherein the advancing element is configured such that advancing the advancing element rotates the insert about an axis substantially perpendicular to the direction of advancement of the advancing element, causing at least one of the cam ramps to travel along at least a portion of at least one of the extensions, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

11. The intervertebral implant of claim 1, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more extensions, wherein the insert comprises at least one cam ramp, wherein the advancing element is configured such that advancing the advancing element rotates the insert about an axis substantially perpendicular to the direction of advancement of the advancing element, causing at least one of the cam ramps to travel along at least a portion of at least one of the extensions, wherein the advancing element is configured to be rotated until an inferior surface of at least one of the cam ramps or a superior surface of at least one of the cam ramps rests on a superior surface of at least one of the extensions or an inferior surface of at least one of the extensions, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

12. The intervertebral implant of claim 1, wherein the upper body or the lower body comprises one or more stabilizers configured to limit the separation distance between the upper body and the lower body.

13. The intervertebral implant of claim 1, further comprising a spacer, wherein the spacer is configured to be positioned between the upper body and the lower body to maintain the increased height of the intervertebral implant.

14. The intervertebral implant of claim 1, wherein the axis of rotation comprises a longitudinal axis of the insert.

15. An intervertebral implant for a human spine, comprising:

an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;

a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine; and

an insert configured to be positioned between the inferior surface of the upper body and the superior surface of the lower body, wherein the insert is configured to rotate about a rotational axis that passes through at least a portion of the insert, wherein the insert comprises one or more projections extending radially relative to the rotational axis, and wherein at least one of the projections comprises a substantially planar surface substantially parallel to the rotational axis; and

an advancing element comprising a longitudinal axis offset from the rotational axis of the insert, wherein linear advancement of the advancing element along the longitudinal axis is configured to cause at least a portion of the advancing element to engage the substantially flat-planar surface of at least one of the projections of the insert such that linear advancement of the advancing element at least partially rotates the insert between the upper body and the lower body such that at least one of the projections of the insert interacts with at least a portion of the upper body or at least a portion of the lower body to increase a height of the intervertebral implant after insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine.

16. The intervertebral implant of claim 15, wherein the insert engages at least a portion of the upper body or at least a portion of the lower body to increase the separation distance between the upper body and the lower body.

17. The intervertebral implant of claim 15, wherein the advancing element is further configured to engage the insert after insertion of the implant between the first vertebra and the second vertebra of the human spine.

18. The intervertebral implant of claim 15, wherein the advancing element is configured to rotate about the longitudinal axis, wherein the longitudinal axis is substantially perpendicular to the rotational axis about which the insert is configured to rotate.

19. The intervertebral implant of claim 15, wherein at least a portion of the upper body is configured to contact at least a portion of the lower body before advancement of the advancing element.

20. The intervertebral implant of claim 15, wherein the advancing element comprises a tapered portion, and wherein the tapered portion of the advancing element is configured to engage the insert.

21. The intervertebral implant of claim 15, wherein the insert further comprises a cylindrical portion, and wherein at least one of the projections comprises an arm that extends radially from the cylindrical portion.

22. The intervertebral implant of claim 15, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more cam ramps, wherein rotation of the insert by the advancing element causes at least one of the projections of the insert to travel along at least a portion of at least one of the cam ramps, thereby increasing a separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

23. The intervertebral implant of claim 15, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more cam ramps, and wherein rotation of the insert by the advancing element causes at least one of the projections of the insert to travel along at least a portion of at least one of the cam ramps, wherein the insert is configured to be rotated until an inferior surface of at least one of the cam ramps or a superior surface of at least one of the cam ramps rests on a superior surface of at least one of the projections of the insert or an inferior surface of at least one of the projections of the insert, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

24. The intervertebral implant of claim 15, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more extensions, wherein the insert comprises at least one cam ramp, wherein the advancing element is configured such that advancing the advancing element rotates the insert about an axis substantially perpendicular to the direction of advancement of the advancing element, causing at least one of the cam ramps to travel along at least a portion of at least one of the extensions, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

25. The intervertebral implant of claim 15, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more extensions, wherein the insert comprises at least one cam ramp, wherein the advancing element is configured such that advancing the advancing element rotates the insert about an axis substantially perpendicular to the direction of advancement of the advancing element, causing at least one of the cam ramps to travel along at least a portion of at least one of the extensions, wherein the advancing element is configured to be rotated until an inferior surface of at least one of the cam ramps or a superior surface of at least one of the cam ramps rests on a superior surface of at least one of the extensions or an inferior surface of at least one of the extensions, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

26. The intervertebral implant of claim 15, wherein the upper body or the lower body comprises one or more stabilizers configured to limit the separation distance between the upper body and the lower body.

27. The intervertebral implant of claim 15, further comprising a spacer, wherein the spacer is configured to be positioned between the upper body and the lower body to maintain the increased height of the intervertebral implant.

28. The intervertebral implant of claim 15, wherein the advancing element is positioned in an opening in a short end of the intervertebral implant.

29. The intervertebral implant of claim 15, wherein the advancing element is positioned in an opening in the anterior side or the posterior side of the implant.

30. The intervertebral implant of claim 15, wherein the rotational axis comprises a longitudinal axis of the insert.

31. An intervertebral implant for a human spine, comprising:

an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;

a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine; and

an insert configured to be positioned between the inferior surface of the upper body and the superior surface of the lower body, wherein the insert is configured to rotate about a rotational axis of the insert, wherein the insert comprises one or more projections comprising a substantially planar surface parallel to the rotational axis; and

an advancing element configured to engage the substantially flat planar surface of the insert such that advancement of the advancing element in a first linear direction along an advancement axis offset from and substantially perpendicular to the rotational axis of the insert at least partially rotates the insert between the upper body and the lower body about the rotational axis of the insert such that the insert interacts with at least a portion of the upper body or at least a portion of the lower body to increase a height of the intervertebral implant after insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine.

32. The intervertebral implant of claim 31, wherein the first linear direction is substantially perpendicular to the rotational axis of the insert.

33. The intervertebral implant of claim 31, wherein the insert engages at least a portion of the upper body or at least a portion of the lower body to increase the separation distance between the upper body and the lower body.

34. The intervertebral implant of claim 31, wherein the advancing element is further configured to engage the insert after insertion of the implant between the first vertebra and the second vertebra of the human spine.

35. The intervertebral implant of claim 31, wherein rotation of the advancing element about the advancement axis is configured to advance the advancing element in the first linear direction along the advancement axis.

36. The intervertebral implant of claim 31, wherein at least a portion of the upper body is configured to contact at least a portion of the lower body before advancement of the advancing element.

37. The intervertebral implant of claim 31, wherein the advancing element comprises a tapered portion, and wherein the tapered portion of the advancing element is configured to engage the insert.

38. The intervertebral implant of claim 31, wherein the insert comprises a cylindrical portion, and wherein at least one of the one or more projections comprises an arm that extends radially from a circumference of the cylindrical portion.

39. The intervertebral implant of claim 31, wherein the insert comprises one or more projections, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more cam ramps, wherein rotation of the insert by the advancing element causes at least one of the projections of the insert to travel along at least a portion of at least one of the cam ramps, thereby increasing a separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

40. The intervertebral implant of claim 31, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more cam ramps, and wherein rotation of the insert by the advancing element causes at least one of the projections of the insert to travel along at least a portion of at least one of the cam ramps, wherein the insert is configured to be rotated until an inferior surface of at least one of the cam ramps or a superior surface of at least one of the cam ramps rests on a superior surface of at least one of the projections of the insert or an inferior surface of at least one of the projections of the insert, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

41. The intervertebral implant of claim 31, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more extensions, wherein the insert comprises at least one cam ramp, wherein the advancing element is configured such that advancing the advancing element rotates the insert about an axis substantially perpendicular to the direction of advancement of the advancing element, causing at least one of the cam ramps to travel along at least a portion of at least one of the extensions, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

42. The intervertebral implant of claim 31, wherein the portion of the upper body or the lower body that interacts with the insert comprises one or more extensions, wherein the insert comprises at least one cam ramp, wherein the advancing element is configured such that advancing the advancing element rotates the insert about an axis substantially perpendicular to the direction of advancement of the advancing element, causing at least one of the cam ramps to travel along at least a portion of at least one of the extensions, wherein the advancing element is configured to be rotated until an inferior surface of at least one of the cam ramps or a superior surface of at least one of the cam ramps rests on a superior surface of at least one of the extensions or an inferior surface of at least one of the extensions, thereby increasing the separation distance between the insert and the lower body or the insert and the upper body, and wherein increasing the separation distance between the insert and the lower body or the insert and the upper body increases the height of the intervertebral implant.

43. The intervertebral implant of claim 31, wherein the upper body or the lower body comprises one or more stabilizers configured to limit the separation distance between the upper body and the lower body.

44. The intervertebral implant of claim 31, further comprising a spacer, wherein the spacer is configured to be positioned between the upper body and the lower body to maintain the increased height of the intervertebral implant.

46. The intervertebral implant of claim 31, wherein the rotational axis comprises a longitudinal axis of the insert.

45. An intervertebral implant for a human spine, comprising:

an upper body comprising a substantially planar shape having an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;

a lower body comprising a substantially planar shape having a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;

an insert disposed between the inferior surface of the upper body and the superior surface of the lower body, wherein the insert comprises a longitudinal axis that extends between and through the upper body and the lower body, wherein the insert comprises a radial projection having a substantially planar surface extending substantially parallel to the longitudinal axis, and wherein the insert is configured to rotate about the longitudinal axis; and

an advancing element configured to be advanced linearly to engage the substantially planar surface of the radial projection of the insert to rotate the insert about the longitudinal axis, wherein rotation of the insert about the longitudinal axis is configured to cause the insert to engage the upper body and/or the lower body to increase a separation distance between the upper body and the lower body, thereby increasing a height of the intervertebral implant after insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine.