Apparatus and methods of reducing bone compression fractures using wedges

• US 20050038517A1
• Filed: 08/13/2003
• Published: 02/17/2005
• Est. Priority Date: 08/13/2003
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Jansen, Lex P., Olson, Stanley W. Jr., Carrison, Harold F.
• Granted Patent: US 7,252,686 B2
• Time in Patent Office: Days
• US Class Current: 623/17.160
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 17/3472 for bones, e.g. intraosseus injections
• CPC Class Codes: A61B 17/8852 capable of being assembled or enlarged, or changing shape, inside the bone or disc
• CPC Class Codes: A61B 2017/00261 Discectomy

Abstract

Devices, kits, and methods are provided for treating a bone structure, e.g., a vertebra, with a compression fracture. Wedges can be introduced into the bone structure in a direction that is lateral to the compression fracture, and stacked on tope of each to apply forces to the bone structure to reduce the compression fracture. The wedges can be introduced into the bone structure using a cannula. The wedges can be introduced as wedge pairs, in which case, a subsequent wedge pair can be introduced between a previously introduced wedge pair in order to drive the previously introduced wedges apart to create the stacking arrangement. Optionally, the wedges can be provided with longitudinal bores, in which case, they can be introduced into the bone structure, over a guide member that is threaded through the bores.

Claims

1. A wedge-shaped device for reducing a bone fracture, comprising a biocompatible body having a leading side, a lagging side opposite and substantially parallel to the leading side, a tapered side between the leading and lagging sides, and a driven side between the leading and lagging sides and opposite the tapered side, the driven side being substantially perpendicular to the leading and lagging sides.

2. The wedge-shaped device of claim 1, wherein the tapered side and leading side form a point.

3. The wedge-shaped device of claim 1, wherein the lagging side is substantially flat in a lateral direction.

4. The wedge-shaped device of claim 1, wherein the lagging side is curved in a lateral direction.

5. The wedge-shaped device of claim 1, wherein the body has a notch formed between the leading and driven sides.

6. The wedge-shaped device of claim 1, wherein the body has a notch formed along the leading side, the notch having a shape that complements the lagging side.

7. The wedge-shaped device of claim 1, wherein the body is sized to fit within a vertebra.

8. The wedge-shaped device of claim 1, wherein the body is composed of polymethylmethacrylate.

9. The wedge-shaped device of claim 1, wherein the body is porous or fenestrated.

10. A kit for reducing a bone fracture, comprising:

a plurality of wedges, each having a first side, a lagging side opposite the leading side, and a tapered side between the leading and lagging sides;

a cannula having a lumen sized to fit a pair of the wedges when the leading sides of the wedge pair engage each other; and

a wedge driver configured for pushing the wedge pair through the cannula lumen.

11. The kit of claim 10, wherein the tapered side and leading side of each wedge form a point.

12. The kit of claim 10, wherein the leading and lagging sides of each wedge are substantially parallel to each other.

13. The kit of claim 12, wherein each wedge has a driven side between the leading and lagging sides and opposite the tapered side, the driven side being substantially perpendicular to the leading and lagging sides.

14. The kit of claim 13, wherein each wedge has a notch formed between the leading and driven sides, the notches of the wedge pair forming an indentation.

15. The kit of claim 14, wherein the wedge driver comprises a protuberance shaped to engage the indentation.

16. The kit of claim 13, wherein each wedge has a notch formed along the leading side, the notch having a shape that complements the lagging side.

17. The kit of claim 10, wherein the wedge pair is sized to fit within a vertebra.

18. The kit of claim 10, wherein each wedge is composed of a biocompatible material.

19. The kit of claim 10, wherein each wedge is composed of polymethylmethacrylate.

20. The kit of claim 10, further comprising another plurality of wedges, each having substantially parallel opposing sides, a blunted side between the opposing sides, and a driven side between the opposing sides and opposite the blunted side, the driven side being substantially perpendicular to the opposing sides.

21. The kit of claim 10, further comprising a plunger assembly configured to be introduced within the cannula lumen.

22. A method of treating a bone structure having opposing sides and a compression fracture therebetween, the method comprising introducing pairs of wedges into the bone structure in a direction lateral to the compression fracture, the wedges in each pair engaging each other in a side-by-side arrangement, wherein a subsequently introduced wedge pair is placed between an immediate previously introduced wedge pair, such that previously introduced pairs of wedges are displaced in opposite directions towards the respective opposing sides of the bone structure.

23. The method of claim 22, wherein the opposing sides of the bone structure are displaced in opposite directions as each subsequently introduced wedge pair is placed between an intermediate previously introduced wedge pair.

24. The method of claim 23, wherein the wedge pairs are introduced into the bone structure until the compression fracture has been completely reduced.

25. The method of claim 22, further comprising inserting a cannula into the bone structure, and introducing the wedge pairs through the cannula into the bone structure.

26. The method of claim 25, wherein the wedge pairs are introduced through the cannula by pushing the wedge pairs with a wedge driver.

27. The method of claim 22, wherein the bone structure is a vertebra.

28. The method of claim 22, wherein each wedge is composed of a biocompatible material.

29. The method of claim 28, wherein each wedge is composed of polymethylmethacrylate.

30. The method of claim 22, further comprising introducing treatment media into the bone structure after introduction of the wedge pairs.

31. A wedge-shaped device for reducing a bone fracture, comprising:

a biocompatible body having a leading side, a lagging side opposite the leading side, a tapered side between the leading and lagging sides;

a bore extending through the body.

32. The wedge-shaped device of claim 31, wherein the body has a driven side opposite the tapered side, and the bore extends through the driven side.

33. The wedge-shaped device of claim 32, wherein the bore extends through the tapered side.

34. The wedge-shaped device of claim 31, wherein the body has a neutral axis through which the bore extends.

35. The wedge-shaped device of claim 31, wherein the body is sized to fit within a vertebra.

36. The wedge-shaped device of claim 31, wherein the bore has a non-circular cross-sectional shape.

37. The wedge-shaped device of claim 31, wherein the body is porous or fenestrated.

38. A kit for reducing a bone fracture, comprising:

a plurality of biocompatible wedges, each of which comprises a bore extending therethrough; and

a guide member sized to fit through the bore.

39. The kit of claim 38, wherein each wedge is sized to fit within a vertebra.

40. The kit of claim 38, further comprising a wedge driver configured for pushing each wedge over the guide member.

41. The kit of claim 40, wherein the wedge driver comprises a bore, and the guide member is sized to fit through the bore of the wedge driver.

42. The kit of claim 38, wherein the guide member is laterally rigid.

43. The kit of claim 38, wherein the guide member is laterally flexible.

44. The kit of claim 38, wherein the bore has a non-circular cross-sectional shape.

45. The kit of claim 44, wherein the guide member has a non-circular cross-sectional shape that is geometrically similar to the cross-sectional shape of the bore.

46. A method of treating a bone structure having opposing sides and a compression fracture therebetween, the method comprising:

introducing a guide member into the bone structure;

introducing wedges over the guide member in a direction lateral to the compression fracture, wherein a subsequently introduced wedge is placed in contact with a previously introduced wedge, such that previously introduced wedges are displaced in a direction towards one or both of the opposing sides of the bone structure.

47. The method of claim 46, wherein the opposing sides of the bone structure are displaced in opposite directions as each subsequently introduced wedge is displaced.

48. The method of claim 46, wherein the wedges are introduced into the bone structure until the compression fracture has been completely reduced.

49. The method of claim 46, wherein the wedges are introduced over the guide member by pushing the wedges with a wedge driver.

50. The method of claim 49, wherein the wedge driver is introduced over the guide member.

51. The method of claim 46, wherein the bone structure is a vertebra.

52. The method of claim 46, wherein each wedge is composed of a biocompatible material.

53. The method of claim 46, further comprising introducing treatment media into the bone structure after introduction of the wedges.

54. The method of claim 46, wherein the guide member is laterally rigid.

55. The method of claim 46, wherein the guide member is laterally flexible, and guide member is bent within the bone structure.

56. The method of claim 46, wherein the wedges are introduced over the guide member as wedge pairs.