Expandable non-threaded spinal fusion device

• US 6,582,431 B1
• Filed: 11/05/1999
• Issued: 06/24/2003
• Est. Priority Date: 02/06/1997
• Status: Expired due to Term

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Ray, Charles Dean
• Primary Examiner(s): REIP, DAVID OWEN
• Application Number:
  US09/436,955
• Time in Patent Office: 1,327 Days
• Field of Search: 606/60, 606/61, 606/71, 606/72, 606/73, 606/75, 623/17.11, 623/17.15, 623/17.16
• US Class Current: 606/86.00A
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/2804 with two or more pivotal connections A61B17/29 takes precedence
• CPC Class Codes: A61B 17/282 Jaws
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• 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 2/4455 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 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• 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 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30237 partial tubes
• CPC Class Codes: A61F 2002/30487 Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• 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 2002/30594 slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30672 : temporary
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30975 : made of two halves
• 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 2002/4622 : having the shape of a forceps or a clamp
• 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 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0069 : cylindrical
• 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 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite

Abstract

An apparatus for facilitating the fusion of adjacent bone structures includes implant members configured for insertion within a space defined between adjacent bone structures. The device provides a series of resilient supporting arches which serve to act as spacers between two adjacent bone structures. The implant members include a longitudinal portion separated by a plurality of ribs and a lateral chamber used to accommodate various sized spacer rods.

Claims

1. A fusion implant system for promoting fusion of adjacent bone structures wherein the fusion implant system contains a bone fusion inducing substance packed therein, the fusion implant system comprising:

a fusion implant having at least two separable sections, each section including arches and at least two lateral stabilizers having a longitudinal axis transverse to the arches.

2. The fusion implant system according to claim 1, wherein the lateral stabilizers include channels along the longitudinal axis and the arches include slots.

3. The fusion implant system according to claim 2, further including at least one spacer to be matingly received within the channels of each lateral stabilizer.

4. The fusion implant system according to claim 3, wherein the at least one spacer includes a set of various sized spacers for varying a distance between the at least two sections.

5. The fusion system according to 3, wherein the at least one spacer further includes engagement apparatus along its transverse outer periphery.

6. The fusion implant system according to claim 5, wherein the channels further include engagement apparatus along their transverse inner periphery.

7. The fusion implant system according to claim 6, wherein the engagement apparatus of both the channels and the spacers engage each other when the fusion implant system is implemented.

8. The fusion implant system according to claim 1, wherein the system is made at least partially from a bio-absorbable material.

9. The fusion implant system according to claim 1, wherein the fusion implant is adapted to be placed within a bore drilled between the two adjacent bone structures and wherein the fusion implant is adapted to be pressed against surrounding walls of the bore so that the arches are pressed into the surrounding walls of the bore.

10. The fusion implant system according to claim 9, wherein the at least one spacer is interposed within the channels of the lateral stabilizers, wherein the spacers are chosen to correspond to a particular height between the fusion implant pressed against the walls of the bore.

11. A method for fusion of adjacent vertebrae having a disk space therebetween, the method comprising the steps of:

accessing the disk space and forming a bore therein;

implanting a fusion implant device within the bore, the fusion implant device including at least two sections, each section including arches and at least two lateral stabilizers having a longitudinal axis transverse to the arches, each lateral stabilizer having a channel along the longitudinal axis;

positioning the at least two sections of the fusion implant within the bore so that the arches penetrate the bone material of the adjacent vertebrae and defining a core area therebetween; and

inserting a spacer along the channel of each lateral stabilizer.

12. The method according to claim 11 wherein the step of positioning includes:

inserting an insertion tool within the bore, the insertion tool including a handle and a tip structure, the tip structure being received within the bore; and

expanding the tip structure within the bore against the at least two sections of the fusion implant thereby forcing the arches into adjacent bone material.

13. The method according to 11, further comprising the step of packing the core area with fusion promoting material.

14. The method according to 11, wherein the channels of the lateral stabilizers and the spacers include mating apparatus to thereby enhance engagement of the lateral stabilizers and the spacers during the inserting step.

15. The method according to 11, wherein the spacer further includes a set of various sized spacers for varying a distance between the at least two sections.

16. A nonthreaded fusion implant system to be implanted in and promote fusion within one or more bone structures, wherein the fusion implant system contains a bone fusion inducing substance packed therein, the fusion implant system comprising:

a fusion implant comprising two halves, each half including arches having an outside portion and an inside portion, wherein the outside portion and the inside portion meet at a confluent edge;

lateral stabilizers positioned along a longitudinal axis of each fusion implant half, the lateral stabilizers having notches or threads along an internal periphery along the longitudinal axis;

slotted spacers positioned along the longitudinal axis of the lateral stabilizers; and

wherein the confluent edges of the arches include a slope between 30 and 45 degrees relative to the longitudinal axis of the fusion implant halves.

17. The nonthreaded fusion implant system according to claim 16, wherein the halves of the fusion implant are positioned within a bore within the bone structures and wherein the halves are forced apart so that the arches are pressed into soft surrounding bone of the bone structures.

18. The nonthreaded fusion implant system according to claim 17, further comprising notches or threads along a portion of the outer periphery of the slotted spacers, and wherein the slotted spacers are positioned within the lateral stabilizers to maintain a desired distracted and axial position between the fusion implant halves.

19. The nonthreaded fusion implant system according to claim 18, further comprising a protective cavity formed between the fusion implant halves once in the distracted and axial positions, wherein the bone fusion growth inducing substance is placed within the protective cavity.

20. The nonthreaded fusion implant system according to claim 18, further comprising an insertion tool having a tip section which is capable of the forcing apart of the fusion implant halves so that slotted spacers may be positioned within the lateral stabilizers.

21. The nonthreaded fusion implant system according to claim 20, wherein the tip of the insertion tool further includes notches to engage the fusion implant halves between the arches to thereby prevent the fusion implant halves from being displaced with respect to the insertion tool during the positioning of the fusion implant halves within the bore.

22. The nonthreaded fusion implant system according to claim 20, wherein the tip section of the insertion tool further includes dual tips separated along a longitudinal axis of the insertion tool, wherein each tip can be axially displaced relative to each other along the longitudinal axis of the insertion tool.

23. The nonthreaded fusion implant system according to claim 20, wherein the tip section of the insertion tool further includes separate blade sections to be inserted along the longitudinal axis of each lateral stabilizer, the separate blade sections forming a bow section therebetween capable of allowing the bone fusion growth inducing substance to be inserted through the bow section.

24. The nonthreaded fusion implant system according to claim 16, wherein the bone fusion growth inducing substance is a force bearing porous preformed core insert.

25. A fusion implant system for promoting fusion of adjacent bone structures wherein the fusion implant system contains a bone fusion inducing substance packed therein, the fusion implant system comprising:

a fusion implant having at least two sections, each section including arches, and

at least two lateral stabilizers having a longitudinal axis transverse to the arches, wherein the lateral stabilizers include channels along the longitudinal axis and the arches include slots.

26. The fusion implant system according to claim 25, further including at least one spacer to be matingly received within the channels of each lateral stabilizer.

27. The fusion implant system according to claim 26, wherein the at least one spacer includes a set of various sized spacers for varying a distance between the at least two sections.

28. The fusion implant system according to claim 26, wherein the at least one spacer further includes engagement apparatus along its transverse outer periphery.

29. The fusion implant system according to claim 28, wherein the channels further include engagement apparatus along their transverse inner periphery.

30. The fusion implant system according to claim 29, wherein the engagement apparatus of both the channels and the spacers engage each other when the fusion implant system is implemented.

31. The fusion implant system according to claim 25, wherein the system is made at least partially from a bio-absorbable material.

32. The fusion implant system according to claim 25, wherein the fusion implant is adapted to be placed within a bore drilled between the two adjacent bone structures and wherein the fusion implant is adapted to be pressed against surrounding walls of the bore so that the arches are pressed into the surrounding walls of the bore.

33. The fusion implant according to claim 32, wherein the at least one spacer is interposed within the channels of the lateral stabilizers, wherein the spacers are chosen to correspond to a particular height between the fusion implant pressed against the walls of the bore.