Spinal fusion implant with bone screws

• US 7,935,149 B2
• Filed: 06/02/2009
• Issued: 05/03/2011
• Est. Priority Date: 04/02/2001
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary K.
• Primary Examiner(s): Philogene; Pedro
• Application Number:
  US12/455,415
• Publication Number:
  US 20090270991A1
• Time in Patent Office: 700 Days
• Field of Search: 623 1711- 1716
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30749 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2002/2817 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 2002/30116 partial circles, i.e. circular segments
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30192 J-shaped
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30517 using a locking plate
• 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 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/30779 : arcuate
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30836 : knurled
• 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 2002/448 : 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 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 2230/0041 : J-shaped
• 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 2310/00029 : 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: Y10S 606/907 : Composed of particular material or coated
• CPC Class Codes: Y10S 606/908 : Bioabsorbable material

Abstract

An interbody spinal fusion implant made of a material other than bone adapted for placement across an intervertebral space formed across the height of a disc space between two adjacent vertebral bodies. The implant has a leading end that is curved to form a portion of a circle from side to side, sides that are at least in part straight, and a trailing end with a bone screw receiving hole for receiving at least one bone screw to engage the vertebral bodies.

Claims

1. An interbody spinal fusion implant for insertion at least in part into an implantation space formed across the height of a disc space between adjacent vertebral bodies of a human spine, the vertebral bodies having a depth and a width, said implant comprising:

a leading end for insertion first into the disc space and a trailing end opposite said leading end, said implant having a length from said leading end to said trailing end and a mid-longitudinal axis along the length;

opposed upper and lower portions between said leading and trailing ends adapted to be placed at least in part within and across the height of the disc space to contact and support the adjacent vertebral bodies, said upper and lower portions defining a height of said implant, said upper and lower portions of said implant including at least one opening in communication with one another for permitting for the growth of bone from vertebral body to vertebral body through said implant;

opposite sides between said upper portion and said lower portion, and between said leading and trailing ends, said opposite sides defining a width of said implant, each of said opposite sides being at least in part straight in a direction from said leading end to said trailing end along at least a portion of the length of said implant, said leading end being curved across the mid-longitudinal axis to form a portion of a circle from one of said opposite sides to another one of said opposite sides, said trailing end being curved from one of said opposite sides to another one of said opposite sides;

a hollow interior between said upper and lower portions, at least one of said opposite sides including at least one opening in communication with said hollow interior;

said trailing end having at least one bone screw receiving hole passing through said trailing end and extending through one of said upper and lower portions of said implant; and

at least one bone screw configured to be inserted into said bone screw receiving hole and extending through one of said upper and lower portions of said implant to engage one of the vertebral bodies;

said implant being manufactured from a material other than bone.

2. The implant of claim 1, further comprising a second bone screw receiving hole passing through said trailing end and extending through one of said upper and lower portions of said implant.

3. The implant of claim 1, further comprising a lock for locking said at least one bone screw to said implant.

4. The implant of claim 3, wherein said lock cooperatively engages said trailing end of said implant.

5. The implant of claim 3, wherein said lock is configured to cover at least a portion of said bone screw receiving hole.

6. The implant of claim 3, wherein said trailing end of said implant includes a recess for receiving said lock.

7. The implant of claim 1, wherein said lock is at least in part threaded.

8. The implant of claim 1, wherein said implant has a maximum width between said opposite sides that is less than one-half of the width of the adjacent vertebral bodies into which said implant is adapted to be inserted.

9. The implant of claim 8, wherein said implant is adapted to be inserted side by side with a second implant into the disc space between the adjacent vertebral bodies, said second implant having a leading end configured in the shape of approximately one quarter of a circle from side to side, the circle having a radius generally equal to the width of said second implant.

10. The implant of claim 1, wherein at least a portion of said leading end has a reduced height to facilitate insertion of said implant between the two adjacent vertebral bodies.

11. The implant of claim 1, wherein the radius of curvature of said trailing end is greater than the radius of curvature of the leading end of said implant.

12. The implant of claim 1, wherein at least one of said opposite sides is at least in part oriented generally parallel to the mid-longitudinal axis of said implant.

13. The implant of claim 1, wherein said opposite sides are at least in part generally parallel one another.

14. The implant of claim 1, wherein at least a portion of said upper and lower portions are in an angular relationship to each other from trailing end to leading end for allowing angulation of the adjacent vertebral bodies relative to each other.

15. The implant of claim 1, further comprising a bone engaging surface formed on the exterior of at least said upper and lower portions for engaging the adjacent vertebral bodies, said bone engaging surface including at least one of a protrusion, a ratchet, a spike, a spline, surface roughenings, and knurling.

16. The implant of claim 1, in combination with a bone growth promoting material.

17. The implant of claim 16, wherein said bone growth promoting material is selected from one of bone, bone derived products, demineralized bone matrix, mineralizing proteins, ossifying proteins, bone morphogenetic protein, hydroxyapatite, and genes coding for the production of bone.

18. The implant of claim 1, wherein at least one of said implant, said lock, and said bone screw is at least in part resorbable.

19. The implant of claim 1, in combination with a chemical substance adapted to inhibit scar formation.

20. The implant of claim 3, wherein said lock includes a recess configured to receive at least a portion of a tool adapted to insert the implant into the implantation space.

21. The implant of claim 3, wherein said lock includes a top and a body, the top having a maximum diameter greater than a maximum diameter of said body.

22. The implant of claim 21, wherein the maximum diameter of said top is greater than a maximum diameter of said at least one bone screw receiving hole.