Composite vertebral spacers and instrument

• US 20080154377A1
• Filed: 12/22/2006
• Published: 06/26/2008
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Medos International Sarl (Johnson & Johnson)
• Original Assignee: Medos International Sarl (Johnson & Johnson)
• Inventors: Voellmicke, John C.
• Granted Patent: US 9,039,768 B2
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• 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 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30166 H-shaped or I-shaped
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30672 temporary
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/3082 Grooves
• 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 2002/4627 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/0091 : connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0028 : Shapes in the form of latin or greek characters
• CPC Class Codes: A61F 2250/0059 : temporary
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00359 : Bone or bony tissue

Abstract

An intervertebral fusion cage that is adapted to contain an inserter within its inner volume during insertion of the cage.

Claims

1. An intervertebral fusion cage, comprising:

a) a leading end having a right and left ends, a front surface and a back surface, the back surface being adapted for reception of a rod,

b) first and second support members extending backwards from the right and left ends and terminating in a respective back surface, each member having an upper and lower surface adapted for bearing against and gripping adjacent vertebral bodies,

c) an open trailing end formed by the back surfaces of the support members.

2. The cage of claim 1 wherein the upper and lower surfaces comprise a plurality of teeth adapted for gripping adjacent vertebral bodies.

3. The cage of claim 1 wherein each support members further comprises a side surface extending between the upper and lower surfaces, each side surface having at least one transverse hole therethrough.

4. The cage of claim 1 wherein the front surface of the leading end is tapered.

5. The cage of claim 1 wherein the back surface of the leading end forms a recess for reception of the rod.

6. The cage of claim 1 wherein the back surface of the leading end forms a threaded recess for reception of the rod.

7. The cage of claim 1 wherein the back surface of the leading end forms a concave recess for reception of the rod.

8. The cage of claim 1 wherein the back surfaces of the support members are adapted for bearing against an inserter.

9. The cage of claim 1 wherein the back surface of each support member has a concave recess.

10. The cage of claim 1 wherein the ends of the leading end and the support members are integrally connected.

11. An apparatus for inserting a fusion cage having a leading end and a trailing end, comprising:

a) a cannula having a bore therethrough, a distal end face and at least two extensions extending distally from the distal end face, each extensions having a distal end adapted for bearing against the trailing end of the cage,

b) a rod slidably received within the bore of the cannula, the rod having a distal end adapted for bearing against the leading end of the cage.

12. The apparatus of claim 11 wherein the rod has a height, and the cage has a height, and the height of the rod exceeds the height of the cage.

13. The apparatus of claim 11 wherein the distal end of each extension has a convex shape.

14. The apparatus of claim 11 wherein the distal end of the rod has a convex shape.

15. The apparatus of claim 11 wherein the bore has a substantially rectangular cross section.

16. An assembly comprising:

a) an intervertebral fusion cage having a leading end and a trailing end, and

b) an inserter comprising;

i) a cannula having a bore therethrough, a distal end face and at least two extensions extending distally from the distal end face, each extension having a distal end bearing against the trailing end of the cage, and

ii) a rod slidably received within the bore of the cannula, the rod having a distal end bearing against the leading end of the cage.

17. An assembly comprising:

a) an intervertebral fusion cage having an interior space, and

b) a rod adapted to insert the cage into an intervertebral space, the rod having a distal end and an intermediate portion,

wherein the distal end of the rod is connected to the cage and

wherein the intermediate portion of the rod is housed within the interior space of the cage.

18. The apparatus of claim 17 wherein the rod has a height defined by an upper and a lower surface, and the cage has a height and an open proximal end, and the height of the rod exceeds the height of the cage.

19. The apparatus of claim 18, wherein each of the upper and lower surfaces of the rod is smooth.

20. A method of inserting a fusion cage, comprising the steps of:

a) providing an intervertebral fusion cage having an interior space,

b) providing an inserter rod having a distal end and an intermediate portion,

c) coupling a distal end of a rod to the cage so that the intermediate portion of the cage occupies interior space of the cage,

d) inserting the cage into an intervertebral space,

e) withdrawing the rod from the cage, and

f) adding a flowable graft material to the interior space of the cage.

21. A method of inserting a fusion cage, comprising the steps of:

a) providing an intervertebral fusion cage having a leading end having a back surface and a trailing end,

b) coupling a distal end of an inserter having a slidable rod therein to the back surface of the leading end of the cage,

c) inserting the cage into an intervertebral space,

d) withdrawing the rod from the cage.

22. The method of claim 21, comprising the steps of:

e) adding a flowable graft material into the cage.

23. The method of claim 21 wherein the rod has a height, and the cage has a height, and the height of the rod exceeds the height of the cage.

24. The method of claim 23 wherein the rod has a smooth upper surface and a smooth lower surface.

25. The method of claim 23 wherein the cage has a toothed upper surface and a toothed lower surface.

26. The method of claim 21 wherein the cage has an open trailing end.

27. The method of claim 21, comprising the further step of:

e) adding a flowable graft material into the cage through the inserter.

28. The method of claim 21 wherein the leading end of the cage has a front surface that is tapered.

29. The method of claim 21 wherein the withdrawing step includes biasing an extension component of the inserter against the trailing end of the cage.

30. The method of claim 21 wherein the cage has a hinge.

31. An implant for promoting bone fusion between adjacent vertebral bodies, said implant having an exterior surface, a longitudinal axis and comprising an assembly of components, said components comprising:

a) a first strut having a first bone-engaging portion, an opposite second bone-engaging portion,

b) a second strut spaced from said first strut, said second strut having a third bone-engaging portion, an opposite fourth bone-engaging portion, said second strut in cooperation with said first strut defining an internal space,

wherein the first strut and the second strut each include an aperture opening into the internal space;

c) an elongate cross-member extending from the first strut to the second strut and including a first end engaged within the first aperture of the first strut and a second end engaged within the aperture of the second strut;

wherein the elongate cross-member is made of a metal.

32. The implant of claim 31 wherein the metal comprises titanium.

33. The implant of claim 31 wherein the metal comprises a titanium alloy.

34. The implant of claim 31 wherein the first and second struts comprise a polymer.

35. The implant of claim 31 wherein the first and second struts comprise a polymer-carbon fiber composite.

36. The implant of claim 31 wherein the polymer is a PAEK.

37. The implant of claim 31 wherein the carbon fiber is in the form of woven fiber.

38. The implant of claim 31 further comprising an osteogenic material interposed between the first and second strut.

39. The implant of claim 31 wherein each strut is in the form of a plank.

40. The implant of claim 31 wherein the first and second struts comprise a polymer-woven carbon fiber composite.

41. An intervertebral fusion cage comprising,

a) a leading end and a trailing end,

b) first and second longitudinal support members extending between each end, each member having an upper and lower surface adapted for bearing against and gripping adjacent vertebral bodies, each upper and lower surface having a longitudinal groove therein, and

c) a plurality of rails, each rail having a smooth outer surface and each rail received in a respective groove of the support member and extending out of the respective groove.

42. The cage of claim 41 wherein the rails are rigid.

43. The cage of claim 41 wherein the rails are flexible.

44. The cage of claim 43 wherein the cage is a banana cage.

45. The cage of claim 41 wherein each rail comprises an outer tube having a smooth outer surface and an inner rod.

46. The cage of claim 41 wherein each rail is molded onto the cage as a fast dissolving polymer.

47. The cage of claim 41 wherein an upper and lower rail comprise a single cable.

48. The cage of claim 47 wherein the cable is coated with a smoothing polymer in order to reduce friction.

49. An intervertebral fusion cage, comprising:

a) a leading portion having a first and second ends extending backwards, a front surface and a back surface, an upper surface and a lower surface, and a pivot hole provided in each of the ends which extends from the upper surface to the lower surface,

b) first and second support members, each support member having;

i. an upper and lower surface adapted for bearing against and gripping adjacent vertebral bodies,

ii. a back surface, the back surfaces forming an open trailing end therebetween,

iii. a front end having a pivot hole which extends from the upper surface of the support member to the lower surface of the support member, and

c) first and second pivot pins respectfully provided in the pivot holes to pivotally connect each end of the leading end and the front end of each support member.

50. The cage of claim 49 wherein the back surface of the leading portion has a recess therein adapted for reception of a rod.

51. The cage of claim 49 wherein each of the upper and lower surfaces of the C-shaped leading portion has a groove extending from the front surface to the back surface for reception of an insertion rail.

52. An intervertebral fusion cage, comprising:

a) a leading end having a right and left ends, a front surface and a back surface,

b) first and second support members extending backwards from the right and left ends and terminating in a respective back surface, each member having an upper and lower surface adapted for bearing against and gripping adjacent vertebral bodies,

c) an open trailing end formed by the back surfaces of the support members, and

d) a strut connecting the first and second support members, the strut being located between the leading end and the open trailing end of the cage, the strut having a back surface being adapted for reception of an inserter rod.

53. The cage of claim 52 wherein the strut has a threaded hole adapted for threaded reception of the rod.