Expandable intervertebral implant with wedged expansion member

• US 8,123,810 B2
• Filed: 05/20/2005
• Issued: 02/28/2012
• Est. Priority Date: 08/05/2003
• Status: Active Grant

• Current Assignee: Flexuspine Incorporated
• Original Assignee: Flexuspine Incorporated
• Inventors: Gordon, Charles R., Harbold, Corey T., Hanson, Heather S.
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): Prone, Christopher D
• Application Number:
  US11/134,069
• Publication Number:
  US 20050278026A1
• Time in Patent Office: 2,475 Days
• Field of Search: None
• US Class Current: 623/17.16
• 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 is described for insertion between vertebrae of a human spine. 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 expansion member. The expansion member may include a first angled portion and a second angled portion. The expansion member may be advanced such that a first angled portion of the expansion member engages an angled portion of the insert to increase a separation distance between the upper body and the lower body of the intervertebral implant. An advancing element may engage a second angled portion of the expansion member such that a direction of advancement of the advancing element is different than the direction of advancement of the expansion member.

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 comprising a superior surface and an inferior surface, wherein the insert is configured to be positioned between the superior surface of the lower body and the inferior surface of the upper body before insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine, and wherein the insert comprises an angled portion;

an expansion member comprising a first angled portion and a second angled portion, wherein the expansion member is configured such that the first angled portion engages the angled portion of the insert to increase a separation distance between the upper body and the lower body after insertion of the intervertebral implant between the first vertebra and the second vertebra; and

an advancing element configured to engage the second angled portion of the expansion member such that the expansion member advances toward the insert in a direction oblique to the direction of advancement of the advancing element.

2. The intervertebral implant of claim 1, wherein engaging the insert comprises elevating the insert.

3. The intervertebral implant of claim 1, wherein the superior surface and the inferior surface of the insert are substantially flat.

4. The intervertebral implant of claim 1, wherein the first angled portion and the second angled portion of the expansion member comprise wedge portions.

5. The intervertebral implant of claim 1, further comprising an advancing element, wherein the advancing element is configured to be advanced in an anteroposterior direction or a posteroanterior direction to engage the second angled portion of the expansion member such that the expansion member advances in a mediolateral direction, allowing the first angled portion of the expansion member to engage the angled portion of the insert.

6. The intervertebral implant of claim 1, wherein the expansion member is configured to be advanced between the superior surface of the lower body and the inferior surface of the insert to increase a separation distance between the lower body and the insert, thereby elevating the insert.

7. The intervertebral implant of claim 1, wherein increasing the separation distance between the upper body and the lower body increases a height of the intervertebral implant.

8. The intervertebral implant of claim 1, wherein the upper body contacts the lower body before expansion of the intervertebral implant.

9. 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 comprising a superior surface and an inferior surface, wherein the insert is configured to be positioned between the superior surface of the lower body and the inferior surface of the upper body before insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine, and wherein the insert comprises an angled portion;

an expansion member comprising a substantially flat inferior surface, a substantially flat superior surface, a first angled portion configured to engage the angled portion of the insert, and a second angled portion; and

an advancing element comprising an angled portion, wherein the advancing elements is configured to be advanced linearly in a first direction such that the angled portion of the advancing element engages the second angled portion of the expansion member, thereby advancing the expansion member linearly in a second direction oblique to the first direction such that the first angled portion of the expansion member engages the angled portion of the insert, thereby increasing a separation distance between the upper body and the lower body of the intervertebral implant.

10. The intervertebral implant of claim 9, wherein the superior surface and the inferior surface of the insert are substantially flat.

11. The intervertebral implant of claim 9, wherein the first angled portion and the second angled portion of the expansion member comprise wedge portions.

12. The intervertebral implant of claim 9, wherein the advancing element is configured to be advanced in a direction substantially perpendicular to the direction of the advancement of the expansion member.

13. The intervertebral implant of claim 9, wherein the advancing element is configured to be advanced in an anteroposterior direction or a posteroanterior direction to engage the second angled portion of the expansion member such that the expansion member advances in a mediolateral direction to engage the angled portion of the insert with the first angled portion of the expansion member.

14. The intervertebral implant of claim 9, wherein increasing the separation distance between the upper body and the lower body increases a height of the intervertebral implant.

15. The intervertebral implant of claim 9, wherein the upper body contacts the lower body before the separation distance between the upper body and the lower body is increased.

16. The intervertebral implant of claim 9, wherein the advancing element is a portion of a tool.

17. 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 expansion member comprising an elongated body having a substantially flat inferior surface, a substantially flat superior surface, and a first angled portion at an insertion end of the elongated body, wherein the expansion member is configured to be positioned between the upper body and the lower body such that applying a force to a trailing end of the elongated body opposite the insertion end of the elongated body is configured to advance the first angled portion and the substantially flat superior and inferior surfaces of the expansion member in a substantially linear direction between and at least partially oblique to at least a portion of the inferior surface of the upper body and at least a portion of the superior surface of the lower body after insertion of the upper and lower body in the spine to increase a separation distance between the superior surface of the upper body and the inferior surface of the lower body.

18. The intervertebral implant of claim 17, wherein applying a force to a face of the trailing end of the expansion member comprising advancing an advancing element into contact with a face of the trailing end of the elongated body of the expansion member, wherein the advancing element advances toward the expansion member in a direction at least partially oblique to the direction of advancement of the expansion member.

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

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

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

an insert comprising an angled portion, wherein the insert is configured to be positioned between the superior surface of the second body and the inferior surface of the first body;

an expansion member comprising a first angled portion and a second angled portion; and

an advancing element configured to move in a first linear direction to engage the second angled portion of the expansion member to move the expansion member in a second linear direction such that the first angled portion of the expansion member engages the angled portion of the insert to increase a separation distance between the first body and the second body to expand the implant after insertion of the intervertebral implant between the first vertebra and the second vertebra, wherein the first linear direction is oblique to the second linear direction.