System and method for spinal fusion

• US 20060058876A1
• Filed: 09/14/2004
• Published: 03/16/2006
• Est. Priority Date: 09/14/2004
• Status: Active Grant

• Current Assignee: Aeolin, LLC
• Original Assignee: Aeolin, LLC
• Inventors: McKinley, Laurence M.
• Granted Patent: US 7,799,081 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• 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 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/30522 releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• 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 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30879 Ribs
• 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 2002/4627 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 2002/4629 connected to the endoprosthesis or implant via a threaded connection
• 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 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• 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

Abstract

The current invention is directed to a system and method for fusing two adjacent vertebrae. In one embodiment, the vertebrae are fused by inserting a self-broaching interbody apparatus into a disc space without the need for separately drilling and broaching. The self-broaching interbody apparatus may include cutting flutes or other broaching means capable of cutting through the cartilaginous endplates of the vertebrae. In another embodiment, an interbody apparatus with an expanding means capable of distracting the disc space between the adjacent vertebrae is inserted into the disc space. Another embodiment includes a sleeve that fits around an interbody apparatus that has at least one opening in its outer surface leading to a cavity filled with bone and/or ortho-biological materials.

Claims

1. An spinal fusion system for fusing two adjacent vertebrae, comprising a self-broaching interbody apparatus with an inside surface, an outside surface, an insertion end and a trailing end, the interbody apparatus configured to be inserted between said adjacent vertebrae.

2. The spinal fusion system of claim 1, wherein the insertion end includes cutting flutes, the cutting flutes projecting from the outside surface in a first direction and configured to cut through a cartilage layer on at least one of said adjacent vertebrae.

3. The spinal fusion system of claim 2, further comprising a keel projecting in substantially the first direction, fixed to the outside surface and aligned behind at least one of the cutting flutes.

4. The spinal fusion system of claim 1, wherein the trailing end includes an edge that projects at least partially outward, such that when the interbody apparatus sits between said adjacent vertebrae, the edge exerts force on said adjacent vertebrae.

5. The spinal fusion system of claim 1, wherein the interbody apparatus further comprises an upper surface, a lower surface and an expanding means,

wherein the expanding means is capable of moving the interbody apparatus from an unexpanded state, where the upper and lower surfaces are at a first distance from each other, to an expanded state, where the upper and lower surfaces are at a second and greater distance from each other.

6. An spinal fusion system for fusing a first and second adjacent vertebrae, comprising a sleeve with an insertion end, a trailing end, an inside surface and an outside surface, the inside surface sized to contain an interbody apparatus, the outside surface sized to be insertable into a surgical opening, and the insertion end and the trailing end having openings.

7. The spinal fusion system of claim 6, wherein a distance between the inside surface of the sleeve and an outer surface of the interbody apparatus is approximately 0.5 mm to 3 mm.

8. The spinal fusion system of claim 6, wherein a distance between the inside surface of the sleeve and an outer surface of the interbody apparatus is approximately 1 mm.

9. The spinal fusion system of claim 6, further comprising an interbody apparatus with an outside surface, the interbody apparatus configured to fit within the inside surface of the sleeve and able to slide through the insertion end opening of the sleeve.

10. The spinal fusion system of claim 9, further comprising a substantially rigid insertion rod sized to fit through the trailing end opening of the sleeve.

11. The spinal fusion system of claim 10, wherein the sleeve is approximately the same length as the insertion rod.

12. The spinal fusion system of claim 9, wherein the outer surface of the interbody apparatus comprises an opening into a body cavity that contains at least one of bone and ortho-biological materials capable of fusing with said adjacent vertebrae,

and wherein the inner surface of the sleeve fits around the outer surface of the interbody apparatus such that the openings are enclosed by the sleeve and the at least one of bone and ortho-biological materials are kept substantially within the cavity.

13. The spinal fusion system of claim 9, wherein the interbody apparatus is self-broaching.

14. The spinal fusion system of claim 6, wherein the sleeve comprises plastic.

15. The spinal fusion system of claim 6, wherein the sleeve comprises metal.

16. The spinal fusion system of claim 6, wherein the sleeve comprises bio-absorbable material.

17. The spinal fusion system of claim 6, wherein the sleeve is rigid.

18. The spinal fusion system of claim 17, wherein the outer surface of the sleeve at the insertion end is larger than a distance between said adjacent vertebrae.

19. The spinal fusion system of claim 6, wherein the sleeve is flexible.

20. An spinal fusion system for fusing two adjacent vertebrae, comprising:

an interbody apparatus with an upper surface, a lower surface, an insertion end and a trailing end; and

an expanding means capable of moving the interbody apparatus from an unexpanded state, where the upper and lower surfaces are at a first distance from each other, to an expanded state, where the upper and lower surfaces are at a second and greater distance from each other,

wherein in the unexpanded state, the interbody apparatus can be inserted between said adjacent vertebrae while a distance between the adjacent vertebrae is in an undistracted state, and

wherein in the expanded state, the interbody apparatus can force the distance between the adjacent vertebrae into a distracted state.

21. The spinal fusion system of claim 20, wherein the expanding means comprises:

upper internal threads fixed to the upper surface and projecting toward the lower surface, the length of the upper internal threads increasing toward the insertion end;

lower internal threads fixed to the lower surface and projecting toward the upper surface, the length of the lower internal threads increasing toward the insertion end; and

a disc having external threads mated with the upper and lower internal threads, such that when the disc is threaded toward the insertion end, the upper and lower surfaces are pushed apart.

22. The spinal fusion system of claim 21, wherein the expanding means further comprises:

rear upper internal threads fixed to the upper surface near the trailing end and projecting toward the lower surface, the length of the rear upper internal threads increasing toward the insertion end;

rear lower internal threads fixed to the lower surface near the trailing end and projecting toward the upper surface, the length of the rear lower internal threads increasing toward the insertion end; and

a back wall disc having external threads mated with the rear upper and rear lower internal threads, such that when the back wall disc is threaded toward the insertion end, the rear upper and rear lower surfaces are pushed apart.

23. The spinal fusion system of claim 21, wherein the expanding means further comprises:

an upper back wall fixed to the upper surface near the trailing end, the upper back wall projecting toward the lower surface and including upper ratchets; and

a lower back wall fixed to the lower surface near the trailing end, the lower back wall projecting toward the upper surface and including lower ratchets, the lower back wall overlapping with the upper back wall in an area of overlap,

wherein the upper ratchets and lower ratchets project toward each other and interlock, such that when the upper and lower surfaces are moved toward the expanded state, the upper ratchets and lower ratchets interlock with a decreasing area of overlap.

24. The spinal fusion system of claim 21, wherein the disc has an opening, the expanding means further comprising an insertion rod configured to fit within the opening such that when it is rotated, the disc rotates with it.

25. The spinal fusion system of claim 20, wherein the expanding means further comprises:

a first oblong cam having a first major radius, the first cam in a substantially perpendicular plane to the upper and lower surfaces inside of the interbody apparatus and rotatable within first grooves in the upper and lower surfaces,

wherein the first cam is shaped such that when it is rotated, the interbody apparatus moves between an expanded state, where the first major radius points toward the upper and lower surfaces and pushes them away from each other, to an unexpanded state, where the first major radius points away from the upper and lower surfaces.

26. The spinal fusion system of claim 25, wherein the expanding means further comprises:

a second oblong cam having a second major radius, the second cam in a substantially perpendicular plane to the upper and lower surfaces inside of the interbody apparatus and rotatable within grooves near the trailing end in the upper and lower surfaces,

wherein the second cam is shaped such that when it is rotated, the interbody apparatus moves between an expanded state, where the second major radius points toward the upper and lower surfaces and pushes them away from each other, to an unexpanded state, where the second major radius points away from the upper and lower surfaces.

27. The spinal fusion system of claim 25, wherein the expanding means further comprises:

an upper back wall fixed to the upper surface near the trailing end, the upper back wall projecting toward the lower surface and including upper ratchets; and

a lower back wall fixed to the lower surface near the trailing end, the lower back wall projecting toward the upper surface and including lower ratchets, the lower back wall overlapping with the upper back wall in an area of overlap,

wherein the upper ratchets and lower ratchets project toward each other and interlock, such that when the upper and lower surfaces are moved toward the expanded state, the upper ratchets and lower ratchets interlock with a decreasing area of overlap.

28. The spinal fusion system of claim 25, wherein the upper surface includes an upper slit and the lower surface includes a lower slit, the upper and lower slits located such that the first oblong cam projects at least partially through the upper and lower slits when the interbody apparatus is in the expanded state.

29. The spinal fusion system of claim 25, wherein the first cam has an opening, the expanding means further comprising an insertion rod configured to fit within the opening such that when it is rotated, the first cam rotates with it.

30. The spinal fusion system of claim 20, wherein the expanding means further comprises:

a first end wall projecting from the upper surface on one of the insertion end and the trailing end toward the lower surface and having a first opening with internal threads;

a second end wall projecting from the lower surface on the other of the insertion end and the trailing end toward the upper surface and having a second opening with internal threads;

first and second sidewalls having first and second projecting edges, the first and second sidewalls fixed to the upper surface and the first end wall, and increasing in size toward the first end wall;

third and fourth sidewalls having third and fourth projecting edges, the third and forth sidewalls fixed to the lower surface and the second end wall, and increasing in size toward the second sidewall;

a second end wall projecting from the lower surface on the other of the insertion end and the trailing end toward the upper surface, the second end wall coupled to the third and fourth sidewalls and having an opening with internal threads; and

a linking screw with external threads that mate with the internal threads of the first and second end walls such that the first and second end walls are pulled toward each other when the linking screw is rotated,

wherein the first and third projecting edges slide against each other and the second and fourth projecting edges slide against each other when the linking screw is rotated.

31. The spinal fusion system of claim 30, wherein the upper and lower surfaces are curved to mate with said adjacent vertebrae.

32. A method for fusing two adjacent vertebrae having respectively first and second facing cartilaginous endplates, the method comprising:

providing a self-broaching interbody apparatus configured to be inserted between said adjacent vertebrae; and

inserting the interbody apparatus between the adjacent vertebrae, such that the interbody apparatus broaches through at least one of said first and second cartilaginous endplates as it is being inserted.

33. A method for fusing two adjacent vertebrae having an undistracted state and a distracted state, comprising:

providing an interbody apparatus having an unexpanded state and an expanded state;

inserting the interbody apparatus in the unexpanded state between said adjacent vertebrae while said adjacent vertebrae are in an undistracted state; and

moving the interbody apparatus to the expanded state after inserting to move the adjacent vertebrae to a distracted state.

34. A method for fusing two adjacent vertebrae, comprising:

providing an interbody apparatus having at least one cavity therein that opens to an outer surface of the interbody apparatus, the cavity containing at least one of bone and ortho-biological material capable of producing a fusion between said adjacent vertebrae;

providing a sleeve configured to at least partially surround the interbody apparatus and hold the at least one of bone and ortho-biological material within the cavity;

positioning the sleeve at an opening between said adjacent vertebrae; and

moving the interbody apparatus completely through the sleeve and between said adjacent vertebrae.