Expandable Ring Intervertebral Fusion Device

• US 20110066192A1
• Filed: 09/15/2009
• Published: 03/17/2011
• Est. Priority Date: 09/15/2009
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Presbrey, Glen, Renganathan, Narendren, Hawkins, John Riley, Fisher, Michael A., Frasier, William
• Granted Patent: US 9,615,933 B2
• Time in Patent Office: Days
• US Class Current: 606/86.A
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• 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 2/4611 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 2002/30062 (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 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30289 helically-coiled
• CPC Class Codes: A61F 2002/30291 spirally-coiled, i.e. having a 2D spiral cross-section
• CPC Class Codes: A61F 2002/30476 locked by an additional locking mechanism
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30583 filled with hardenable fluid, e.g. curable in-situ
• 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 2002/30601 telescopic
• CPC Class Codes: A61F 2002/30672 temporary
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/4415 elements of the prosthesis being arranged in a chain like manner
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0085 : hardenable in situ, e.g. epoxy resins
• 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 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0059 : temporary

Abstract

An expandable tube having a substantially semicircular unexpanded shape is inserted into the disc space after the disc material has been removed therefrom. A plurality of expandable lockable rings are passed over this tube in their unexpanded states and positioned along the anterior edge of the endplates. The tube is then expanded, thereby forcing the rings to expand. The rings hold their final expanded configuration via a one-way locking mechanism. Once sufficient distraction is achieved and the rings locked, the tube is collapsed and removed, thereby leaving the expanded, locked rings behind to support the disc space.

Claims

1. An assembly for inserting an intervertebral fusion device, comprising:

a) a first flexible tube having an outer radius and a throughbore, a first unexpanded state and a second expanded state,

b) a plurality of rings having a first unexpanded state and a second expanded, locked state,

wherein each ring surrounds the outer radius of the tube,

wherein the plurality of rings are in their unexpanded states when the tube is initially in its unexpanded state, and

wherein the plurality of rings are in their locked expanded states once the tube has been placed in its expanded state.

2. The assembly of claim 1 wherein each ring in its expanded locked state has a diameter substantially corresponding to a height of a disc space.

3. The assembly of claim 1 wherein each ring in its expanded state has a first row of gripping teeth extending outwards for gripping a first vertebral endplate.

4. The assembly of claim 1 wherein each ring in its expanded state has a second row of gripping teeth extending outwards for gripping a second vertebral endplate.

5. The assembly of claim 1 further comprising:

c) a fluid provided in the throughbore of the first flexible tube.

6. The assembly of claim 1 wherein each ring has a first and second end, the first end having a first mating tooth, the second end having a second mating tooth, wherein the first and second mating teeth mate with each other in the expanded state to prevent movement of the ring to its unexpanded state.

7. The assembly of claim 1 further comprising:

c) a second flexible tube surrounding the first flexible tube and connecting the plurality of rings.

8. The assembly of claim 7 wherein the second flexible tube is adapted to promote vascularization and engraftment.

9. An intervertebral fusion device for supporting a disc space, comprising:

a) a substantially semicircular array of rings having a first unexpanded state and a second expanded, locked state,

wherein each ring in its expanded, locked state has a diameter corresponding substantially to a height of the disc space.

10. The device of claim 9 wherein each ring in its expanded, locked state has a first row of gripping teeth extending outwards for gripping a first vertebral endplate.

11. The device of claim 9 wherein each ring in its expanded, locked state has a second row of gripping teeth extending outwards for gripping a second vertebral endplate.

12. The device of claim 9 wherein each ring has a first and second end, the first end having a first mating tooth, the second end having a second mating tooth, wherein the first and second mating teeth mate with each other in the expanded state to prevent movement of the ring to its unexpanded state.

13. The device of claim 9 wherein the plurality of rings are present in the form of a plurality of spiral coils.

14. The device of claim 13 wherein the plurality of spiral coils are nested.

15. The device of claim 13 wherein the plurality of spiral coils are made of a memory metal.

16. The device of claim 9 wherein each ring comprises chain links forming a linked chain.

17. The device of claim 9 wherein at least one ring comprises a sliding keyway.

18. A method of distracting a disc space having opposing vertebral endplates, comprising the steps of:

a) inserting a tube having a throughbore into the disc space,

b) passing a plurality of rings having a one-way locking mechanism over the tube in a first unexpanded state,

c) positioning the plurality of rings along an anterior edge of the endplates,

d) expanding the tube to force the rings to a second expanded locked state,

e) collapsing the expanded tube to leave the locked rings behind to support the disc space, and

f) removing the tube.

19. The method of claim 18 wherein each ring in its expanded locked state has a diameter substantially corresponding to a height of the disc space.

20. The method of claim 18 wherein each ring in its expanded locked state has a first row of gripping teeth extending outwards for gripping a first vertebral endplate.

21. The method of claim 18 wherein each ring in its expanded locked state has a second row of gripping teeth extending outwards for gripping a second vertebral endplate.

22. The method of claim 18 wherein the expansion step comprises providing a fluid in the throughbore of the flexible tube.

23. The method of claim 18 wherein each ring has a first and second end, the first end having a first mating tooth, the second end having a second mating tooth, wherein the first and second mating teeth mate with each other in the expanded locked state to prevent return of the ring to its unexpanded state.

24. A method of distracting a disc space having opposed vertebral endplates, comprising the steps of:

a) inserting a tube into the disc space, the tube carrying a plurality of rings thereon, wherein the rings are in a first unexpanded state and have a one-way locking mechanism,

b) positioning the rings along an anterior edge of the endplates,

c) expanding the tube to force the rings to expand and lock,

d) collapsing the expanded tube to leave behind the rings to support the disc space, and

e) removing the tube.

25. A method of making an in-situ formed intervertebral fusion cage, comprising the steps of:

a) inserting an assembly into a disc space, the assembly comprising an expandable balloon having a plurality of expandable rings thereon,

b) expanding the expandable balloon to expand the expandable rings.

26. A method of making an in-situ formed intervertebral fusion cage, comprising the steps of:

a) inserting into a disc space a fusion ring in an unexpanded state,

b) expanding the ring to an expanded state.

27. A method of making an in-situ formed intervertebral fusion cage, comprising the steps of:

a) inserting into a disc space a spiral-shaped fusion ring having an inner end and a outer end, wherein the ends overlap,

b) expanding the ring so that the first end abuts the second end.

28. An assembly for inserting an intervertebral fusion device, comprising:

a) a first flexible tube having an outer radius and a throughbore, a first unexpanded state and a second expanded state,

b) a plurality of bladder rings having a first unexpanded state and a second expanded, locked state,

wherein each bladder ring surrounds the outer radius of the tube and is filled with a curable component,

wherein the plurality of rings are in their unexpanded states when the tube is initially in its unexpanded state, and

wherein the plurality of bladder rings are in their expanded states once the tube has been placed in its expanded state.

29. An intervertebral fusion device comprising an assembly for inserting an intervertebral fusion device, comprising:

a) a first flexible tube having an outer radius and a throughbore, a first unexpanded state and a second expanded state,

b) a plurality of expandable rings having a first unexpanded state and a second expanded, locked state, wherein each ring comprises;

i) upper and lower plates, each plate having an outer surface adapted for gripping a vertebral endplate and an inner surface adapted for bearing against the outer radius of the first flexible tube, and

ii) a pair of elongatable struts connecting the upper and lower plates, each strut adapted to resist recession,

wherein each expandable ring surrounds the outer radius of the tube,

wherein the plurality of rings are in their unexpanded states when the tube is initially in its unexpanded state, and

wherein the plurality of rings are in their expanded states once the tube has been placed in its expanded state.

30. An intervertebral fusion device comprising:

a) first U-shaped component having first and second legs and an intermediate curved region comprising a convex surface and a concave surface,

b) second U-shaped component having first and second legs and an intermediate curved region comprising a convex surface and a concave surface,

wherein the concave surfaces oppose each other, and the convex surfaces are adapted for gripping respective opposed vertebral endplates, and

wherein the first legs of each component are adapted to nest with each other to form a first keyway, and

wherein the second legs of each component are adapted to nest with each other to form a second keyway.

31. The device of claim 30 further comprising a securement pin, wherein the first legs of each component further comprise a throughhole, and wherein the securement pin passes through each throughhole.

32. The device of claim 30 wherein the first legs of each component further comprise ratchet teeth adapted for one way movement.