INTERVERTEBRAL IMPLANT

• US 20080140207A1
• Filed: 12/07/2007
• Published: 06/12/2008
• Est. Priority Date: 12/07/2006
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Interventional Spine, Inc (Johnson & Johnson)
• Inventors: Olmos, Fausto, Flower, Bob, Culbert, Brad
• Granted Patent: US 8,105,382 B2
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A01H 5/12 Leaves
• CPC Class Codes: A24B 13/00 Tobacco for pipes, for cigars, e.g. cigar inserts, or for cigarettes; Chewing tobacco; Snuff reconstituted tobacco products A24B3/14
• CPC Class Codes: A24B 15/18 Treatment of tobacco products or tobacco substitutes
• CPC Class Codes: A24D 1/00 Cigars; Cigarettes
• CPC Class Codes: A24F 47/00 Smokers' requisites not otherwise provided for
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/46 Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30522 releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/30523 by means of meshing gear teeth
• 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 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30677 : Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30785 : parallel
• 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 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2002/4659 : for measuring a diameter
• CPC Class Codes: A61F 2002/4661 : for measuring thickness
• CPC Class Codes: A61F 2002/4667 : for measuring torque
• 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 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: Y02E 50/10 : Biofuels, e.g. bio-diesel

Abstract

An adjustable spinal fusion intervertebral implant is provided that can comprise upper and lower body portions that can each have proximal and distal wedge surfaces disposed at proximal and distal ends thereof. An actuator shaft disposed intermediate the upper and lower body portions can be actuated to cause proximal and distal protrusions to converge towards each other and contact the respective ones of the proximal and distal wedge surfaces. Such contact can thereby transfer the longitudinal movement of the proximal and distal protrusions against the proximal and distal wedge surfaces to cause the separation of the upper and lower body portions, thereby expanding the intervertebral implant.

Claims

1. An adjustable spinal fusion intervertebral implant comprising:

upper and lower body portions each having proximal and distal surfaces at proximal and distal ends thereof, the proximal and distal surfaces of the upper and lower body portions generally facing each other;

an actuator shaft received between the upper and lower body portions, the actuator shaft comprising an inner member and an outer sleeve member moveable relative to the inner member, the inner member having distal and proximal ends and at least one retention structure disposed therebetween, the outer sleeve member having a proximal end and at least one complementary retention structure to engage the retention structure of the inner member to facilitate selective relative movement of the proximal end of the outer sleeve member toward the distal end of the inner member without rotation;

a proximal wedge member disposed at the proximal end of the outer sleeve member configured to contact the proximal surfaces of the upper and lower body portions upon selective relative movement of the proximal end of the outer sleeve member toward the distal end of the inner member; and

a distal wedge member disposed at the distal end of the inner member, the and configured to contact the distal surfaces of the upper and lower body portions upon selective relative movement of the distal end of the inner member toward the proximal end of the outer sleeve member;

wherein the longitudinal movement of the distal wedge member against the distal surfaces and the longitudinal movement of the proximal wedge member against the proximal surfaces causes separation of the upper and lower body portions.

2. The implant of claim 1 wherein the proximal wedge member is formed integrally with the outer sleeve member of the pin.

3. The implant of claim 1 wherein the proximal member as an axially tapering distal facing surface.

4. The implant of claim 1 wherein the proximal wedge member includes an engagement surface and the proximal surfaces of the upper and lower body portions include a complimentary engagement surface configured to engage the engagement surface of the proximal protrusion to permit one-way longitudinal movement of the proximal protrusion relative to the wedged elements for maintaining the upper and lower body portions at a given separation distance.

5. The implant of claim 1 wherein the distal wedge member is formed integrally with the inner member of the pin.

6. The implant of claim 1 wherein the distal wedge member has tapering proximally facing surface.

7. The implant of claim 1 wherein the distal wedge member includes an engagement surface and the distal surfaces of the upper and lower body portions include a complimentary engagement surface configured to engage the engagement surface of the proximal protrusion to permit one-way longitudinal movement of the proximal protrusion relative to the wedged elements for maintaining the upper and lower body portions at a given separation distance.

8. The implant of claim 1 further including an alignment guide extending at least partially through the upper and lower body portions.

9. The implant of claim 8, wherein the separation of the upper and lower body portions occurs in a direction substantially orthogonal to an axis of the pin.

10. The implant of claim 8 further wherein the alignment guide includes at least one guide rod being disposed through the upper and lower body portions for orienting the upper body portion substantially orthogonally with respect to an axis of the actuator shaft and with respect to the lower body portion, the guide rod facilitating separation of the upper and lower body portions in a direction substantially orthogonal to the axis.

11. The implant of claim 8 wherein the alignment guide includes a first pair of side rails extending from the upper body portion toward the lower body portion for aligning the upper body portion with the lower body portion to facilitate separation of the upper and lower body portions in a direction substantially orthogonal to an axis of the pin.

12. The implant of claim 11 wherein the alignment guide further includes a second pair of side rails extending from the lower body portion toward the upper body portion for cooperating with the first pair of side rails in aligning the upper body portion with the lower body portion to facilitate separation of the upper and lower body portions in a direction substantially orthogonal to the axis of the pin

13. The implant of claim 1 wherein the retention structures of the inner member and the outer sleeve member permit proximal movement of the inner member with respect to the outer sleeve member but resist distal movement of the inner member with respect to the outer sleeve member.

14. The implant of claim 1 wherein the retention structure of the inner member and the complementary retention structure of the outer sleeve member comprise a series of ridges and grooves.

15. The implant of claim 1 wherein the upper and lower body portions are substantially configured as parallel plates.

16. The implant of claim 1 wherein the inner member of the actuator shaft comprises first and second sections, the first section being attached to the second section during relative movement of the outer sleeve member with respect to the inner member to facilitate expansion of the implant, the first section being removable from the second section after expansion of the implant.

17. An adjustable spinal fusion intervertebral implant comprising:

upper and lower body portions each having proximal and distal surfaces at proximal and distal ends thereof, the proximal and distal surfaces of the upper and lower body portions generally facing each other;

an actuator shaft received between the upper and lower body portions, the actuator shaft comprising an inner member and an outer sleeve member selectively moveable relative to the inner member;

a distal wedge member disposed at a distal end of the inner member, the distal wedge member having an engagement surface configured to provide ratchet-type engagement with the distal surfaces of the upper and lower body portions upon selective relative movement of the distal end of the inner member toward the proximal end of the outer sleeve member; and

a proximal wedge member disposed at a proximal end of the outer sleeve member, the proximal wedge member having an engagement surface configured to provide ratchet-type engagement with the proximal surfaces of the upper and lower body portions upon selective relative movement of the proximal end of the outer sleeve member toward the distal end of the inner member;

wherein longitudinal movement of the distal wedge member against the distal surfaces and the longitudinal movement of the proximal wedge member against the proximal surfaces causes separation of the upper and lower body portions, and wherein the ratchet-type engagement between the distal and proximal wedge members and the respective ones of the proximal and distal surfaces of the upper and lower body portions maintains separation of the upper and lower body portions.

18. The implant of claim 17 wherein the inner member of the actuator shaft includes at least one retention structure disposed thereon and the outer sleeve member includes at least one complementary retention structure configured to engage the retention structure of the inner member to provide one-way ratchet-type engagement therebetween as the upon relative movement of the proximal end of the outer sleeve member toward the distal end of the inner member without rotation.

19. A method of implanting an expandable intervertebral implant comprising:

positioning the implant between two vertebral bodies;

moving an inner member of an actuator shaft of the implant in an proximal direction relative to an outer sleeve member disposed about the inner sleeve member to force a wedge member against a surface of upper and lower body portions of the implant to separate the upper and lower body portions to cause the implant to expand.

20. A method of implanting an expandable intervertebral implant comprising:

positioning the implant between two vertebral bodies;

rotating a screw mechanism of the implant to cause proximal and distal wedge members to converge toward each other and engage respective ones of proximal and distal surfaces of upper and lower body portions of the implant to separate the upper and lower body portions to cause the implant to expand.

21. An adjustable spinal fusion intervertebral implant comprising:

upper and lower body portions each having proximal and distal surfaces at proximal and distal ends thereof, the proximal and distal surfaces of the upper and lower body portions generally facing each other, the proximal surfaces of the respective ones of the upper and lower body portions each defining a proximal slot therein, and distal surfaces of the respective ones of the upper and lower body portions each defining a distal slot therein;

a proximal wedge member disposed at the proximal ends of the respective ones of the upper and lower body portions, the proximal wedge member comprising upper and lower guide members extending at least partially into the respective ones of the proximal slots of the upper and lower body portions with at least a portion of the proximal wedge member contacting the proximal surfaces of the upper and lower body portions;

a distal wedge member disposed at the distal ends of the respective ones of the upper and lower body portions, the distal wedge member comprising upper and lower guide members extending at least partially into the respective ones of the distal slots of the upper and lower body portions with at least a portion of the distal wedge member contacting the distal surfaces of the upper and lower body portions; and

an actuator shaft received between the upper and lower body portions, the actuator shaft extending intermediate the distal and proximal wedge members, wherein rotation of the actuator shaft causes the distal and proximal wedge members to be drawn together such that longitudinal movement of the distal wedge member against the distal surfaces and the longitudinal movement of the proximal wedge member against the proximal surfaces causes separation of the upper and lower body portions.

22. The implant of claim 21, wherein the upper body portion further comprises a pair of downwardly extending side members and the lower body portion further comprises a pair of upwardly extending side members, the side members of the upper body portion engaging the side members of the lower body portion to facilitate linear translational movement of the upper body portion relative to the lower body portion.

23. The implant of claim 22, wherein the side members of the upper body portion each comprise a slot and the side members of the lower body portion each comprise a guide member, the guide members of the side members of the lower body portion each being received into the slots of the side members of the upper body portion.

24. The implant of claim 21, wherein the proximal and distal surfaces of the upper and lower body portions are sloped.

25. The implant of claim 24, wherein the slots of the proximal and distal surfaces of the upper and lower body portions are sloped.

26. The implant of claim 25, wherein the slots of the proximal and distal surfaces of the upper and lower body portions are generally parallel to the respective proximal and distal surfaces of the upper and lower body portions.

27. The implant of claim 21, wherein the slots of the proximal and distal surfaces of the upper and lower body portions are generally dove-tailed.

28. The implant of claim 27, wherein the guide members of the proximal and distal wedge members are generally dovetailed.

29. The implant of claim 21, wherein the upper and lower body portions comprise generally arcuate respective upper and lower exterior engagement surfaces.

30. The implant of claim 21, wherein the proximal wedge member comprises an anti-rotational element, the anti-rotational engagement being configured to be engaged by an implant tool for preventing rotation of the implant when the actuator shaft is rotated relative to the implant.

31. The implant of claim 30, wherein the anti-rotational element comprises a pair of apertures extending into the proximal wedge member.

32. An implantation tool for implanting an expandable intervertebral implant, the tool comprising:

a handle section comprising a fixed section and first and second rotatable members;

a distal engagement section comprising a fixed portion and first and second rotatable portions being operatively coupled to the respective ones of the first and second rotatable members, the first rotatable portion comprising a distal attachment element, the distal engagement element being operative to be removably attached to a distal end of at least a portion of the implant, the second rotatable portion comprising a distal engagement member being configured to engage a proximal end of an actuator shaft of the implant for rotating the actuator shaft to thereby and expanding the implant from an unexpanded state to and expanded state; and

an anti-rotational engagement member for engaging an anti-rotational element of the implant.

33. The tool of claim 32, wherein the first and second rotatable members are coaxially aligned.

34. The tool of claim 32, wherein the first and second rotatable portions are coaxially aligned.

35. The tool of claim 34, wherein the first and second rotatable portions are tubular, the first rotatable portion being disposed internally to the second rotatable portion.

36. The tool of claim 35, wherein the fixed portion of the distal engagement section is tubular and the first and second rotatable portions are disposed internally to the fixed portion.