Interbody spinal fusion implants with end cap for locking vertebral body penetrating members

• US 7,033,394 B2
• Filed: 05/23/2003
• Issued: 04/25/2006
• Est. Priority Date: 05/05/1999
• Status: Expired due to Term

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary K.
• Primary Examiner(s): Willse, David H.
• Application Number:
  US10/444,216
• Publication Number:
  US 20030199983A1
• Time in Patent Office: 1,068 Days
• Field of Search: 623 1711- 1713, 623/17.16, 623/FOR.17
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/686 Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/8038 the additional component being inserted in the screw head
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: A61B 17/8057 the interlocking form comprising a thread
• CPC Class Codes: A61B 17/861 specially shaped for gripping driver
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches
• CPC Class Codes: A61B 17/8894 holding the implant into or through which the screw is to be inserted A61B17/7082, A61B17/7091 take precedence
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• 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 2/4637 for connecting or disconnecting two parts of a prosthesis
• 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 2002/30131 : horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30143 : hexagonal
• CPC Class Codes: A61F 2002/30153 : rectangular
• CPC Class Codes: A61F 2002/30158 : trapezoidal
• CPC Class Codes: A61F 2002/30187 : D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2002/3021 : frustoconical
• CPC Class Codes: A61F 2002/30217 : hollow cones, e.g. tubular-like cones
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30237 : partial tubes
• CPC Class Codes: A61F 2002/30266 : wedge-shaped parallelepipeds
• CPC Class Codes: A61F 2002/30405 : made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30858 : Threads interrupted by grooves or sidewalls, e.g. flat sidewalls
• CPC Class Codes: A61F 2002/30861 : having threads of increasing or decreasing height
• CPC Class Codes: A61F 2002/30871 : Trapezoidal threads
• CPC Class Codes: A61F 2002/30878 : with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• 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 2002/4638 : Tools for performing screwing, e.g. nut or screwdrivers, or particular adaptations therefor
• 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 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0034 : D-shaped
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• 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 2310/00131 : Tantalum or Ta-based 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
• CPC Class Codes: A61F 2310/00359 : Bone or bony tissue
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: A61F 2310/00976 : Coating or prosthesis-covering structure made of proteins or of polypeptides, e.g. of bone morphogenic proteins BMP or of transforming growth factors TGF

Abstract

An apparatus including an interbody spinal fusion implant having a leading end, a trailing end, and a length therebetween, and opposed upper and lower portions adapted to contact each of the adjacent vertebral bodies. Each of the upper and lower portions having at least one opening adapted to communicate with one each of the adjacent vertebral bodies and to communicate with one another to permit for the growth of bone from vertebral body to adjacent vertebral body through the implant. Each of the upper and lower portions has at least one screw hole passing therethrough proximate the trailing end. The apparatus further includes bone screws adapted for placement through the screw holes of the upper and lower portions and into each of the adjacent vertebral bodies adjacent the disc space to be fused and into which the implant is adapted to be positioned. At least one lock may be used to prevent the bone screws from backing out of the vertebral bodies and implant.

Claims

1. An apparatus comprising:

an interbody spinal fusion implant for surgical implantation at least in part within a disc space between two adjacent vertebral bodies in a segment of a human spine, said implant comprising an interior, a leading end for entry into the spine, a trailing end opposite said leading end, and a length therebetween, and upper and lower portions for contacting each of the adjacent vertebral bodies when positioned therein, said upper and lower portions having a maximum height therebetween, each of said upper and lower portions having at least one opening adapted to communicate with one of the adjacent vertebral bodies, said openings in said upper and lower portions being in communication with one another and adapted to permit for the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant, said trailing end having an interior and an outermost exterior surface opposite said leading end, said implant including at least two vertebral body penetrating member receiving holes passing through said interior of said trailing end, through said interior of said implant, and through each of said upper and lower portions proximate said trailing end, said trailing end having at least one aperture in communication with at least one of said vertebral body penetrating member receiving holes in said upper and lower portions;

vertebral body penetrating members adapted for placement through said at least one aperture in said trailing end, through at least a portion of said interior of said trailing end, and through said holes in said upper and lower portions and into each of the adjacent vertebral bodies adjacent the disc space to be fused and into which said implant is adapted to be positioned; and

a cap adapted to be coupled to said trailing end of said implant to prevent movement of said vertebral body penetrating members in a direction opposite to the direction of insertion of said vertebral body penetrating members into said aperture in said trailing end of said implant, said cap having a maximum dimension being less than the maximum height between said upper and lower portions of said implant.

2. The apparatus of claim 1, wherein said implant further comprises a hollow interior for holding bone growth promoting material, said hollow interior being in communication with said at least one opening in each of said upper and lower portions.

3. The apparatus of claim 1, wherein said vertebral body penetrating member receiving holes are opposed and divergently angled to one another.

4. The apparatus of claim 1, wherein said implant has a mid-longitudinal axis, said vertebral body penetrating member receiving holes being angled between 25 and 75 degrees from said mid-longitudinal axis of said implant.

5. The apparatus of claim 1 wherein said vertebral body penetrating member receiving holes are opposed and divergently angled and extend from said trailing end and through said upper and lower portions.

6. The apparatus of claim 5, wherein said vertebral body penetrating member receiving holes extending from said trailing end are configured so as to be adapted to be oriented towards the adjacent vertebral bodies in half rotation increments of said implant.

7. The apparatus of claim 1, wherein at least a portion of said vertebral body penetrating members is adapted to pass from said interior of said implant through said vertebral body penetrating member receiving holes and into the adjacent vertebral body to anchor said implant to the adjacent vertebral body.

8. The apparatus of claim 1, wherein said vertebral body penetrating members have a sharp distal end.

9. The apparatus of claim 1, wherein said vertebral body penetrating members have a distal end and a head opposite said distal end, said head being adapted to engage a driving instrument.

10. The apparatus of claim 1, wherein said vertebral body penetrating members are at least in part made of a resorbable material.

11. The apparatus of claim 1, wherein said vertebral body penetrating members comprise a metal suitable for human implantation.

12. The apparatus of claim 1, wherein said trailing end of said implant is configured to cooperatively engage an implant driver.

13. The apparatus of claim 1, wherein said cap has a bearing surface for bearing against a portion of at least one of said vertebral body penetrating members.

14. The apparatus of claim 1, wherein said cap comprises a threaded member.

15. The apparatus of claim 1, wherein said cap covers at least a portion of at least one of said at least one apertures in said trailing end of said implant and said vertebral body penetrating member receiving holes.

16. The apparatus of claim 1, wherein said upper and lower portions are parallel to one another.

17. The apparatus of claim 1, wherein said upper and lower portions are convergent to one another.

18. The apparatus of claim 1, wherein said upper and lower portions are generally planar surfaces.

19. The apparatus of claim 1, wherein said upper and lower portions are opposed arcuate portions.

20. The apparatus of claim 19, wherein said opposed arcuate portions form at least a portion of a cylinder along the length of said implant.

21. The apparatus of claim 1, wherein each of said tipper and lower portions have at least one bone engaging projection thereon.

22. The apparatus of claim 21, wherein said projection is at least one of a fin, a ridge, and a thread.

23. The apparatus of claim 2, wherein at least one of said leading and trailing ends is open to allow access to said hollow interior.

24. The apparatus of claim 1, wherein said implant comprises an artificial material other than bone.

25. The apparatus of claim 1, wherein said implant is made of an artificial material that is stronger than bone.

26. The apparatus of claim 1, wherein said implant is made of an artificial material that is harder than bone.

27. The apparatus of claim 1, wherein said implant comprises bone.

28. The apparatus of claim 1, wherein said implant comprises bone growth promoting material.

29. The apparatus of claim 28, wherein said bone promoting material is compressive loaded into said implant.

30. The apparatus of claim 28, wherein said bone growth promoting material is selected from one of bone morphogenetic protein, hydroxyapatite, and genes coding for the production of bone.

31. The apparatus of claim 1, wherein said implant is treated with a bone growth promoting substance.

32. The apparatus of claim 1, wherein said implant is a source of osteogenesis.

33. The apparatus of claim 1, wherein said implant is at least in part bioabsorbable.

34. The apparatus of claim 1, wherein said implant comprises a plastic material.

35. The apparatus of claim 1, wherein said implant comprises a ceramic material.

36. The apparatus of claim 1, wherein said implant is formed of a porous material.

37. The apparatus of claim 1, wherein said implant is formed of a material that intrinsically participates in the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant.

38. The apparatus of claim 1, in combination with a chemical substance to inhibit scar formation.

39. The apparatus of claim 1, in combination with a fusion promoting substance.

40. The apparatus of claim 39, wherein said fusion promoting substance includes at least one of bone, bone morphogenetic protein, hydroxyapatite, and genetic materials coding for the production of bone.

41. The apparatus of claim 1, in combination with an orthopedic device for use in spinal surgery.

42. The apparatus of claim 41, wherein said orthopedic device is a bone removal device for preparing a space between and at least in part into the adjacent vertebral bodies.

43. The apparatus of claim 42, wherein said bone removal device is one of a drill and a mill.

44. The apparatus of claim 41, wherein said orthopedic device is an implant driver for inserting said spinal implant.

45. The apparatus of claim 41, wherein said orthopedic device is a distractor for distracting the disc space between the adjacent vertebral bodies.

46. The apparatus of claim 41, wherein said orthopedic device is a sleeve for providing protected access to the disc space between the adjacent vertebral bodies.

47. The apparatus of claim 1, wherein said cap has a central longitudinal axis, a maximum dimension transverse to the central longitudinal axis, and an outer perimeter defined by the maximum transverse dimension, said outer perimeter being threaded.

48. The apparatus of claim 1, wherein said cap is threaded, said cap having a central longitudinal axis and a thread diameter transverse to the central longitudinal axis, each of said vertebral body penetrating members having a longitudinal axis and a thread diameter transverse to the longitudinal axis, the thread diameter of said cap being greater than the thread diameter of at least one of said vertebral body penetrating members.

49. The apparatus of claim 1, further comprising at least a second cap adapted to be coupled to said trailing end of said implant to prevent movement of at least one of said vertebral body penetrating members in a direction opposite to the direction of insertion of said at least one of said at least one of said vertebral body penetrating members into said aperture in said trailing end of said implant.