Biodegradable/bioactive nucleus pulposus implant and method for treating degenerated intervertebral discs

• US 7,156,877 B2
• Filed: 05/24/2002
• Issued: 01/02/2007
• Est. Priority Date: 06/29/2001
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Bradford, David S., Lotz, Jeffrey C., Colliou, Olivier K.
• Primary Examiner(s): Philogene; Pedro
• Application Number:
  US10/154,857
• Publication Number:
  US 20030033017A1
• Time in Patent Office: 1,684 Days
• Field of Search: 623/17.11, 623/17.12, 623/17.16, 623/17.15, 623/23.67, 623/23.68, 623/7, 623/8, 623/11.11, 623/23.34, 606/90, 606/195, 606/192
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• 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 2002/4635 using minimally invasive surgery
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0015 Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2310/00365 Proteins; Polypeptides; Degradation products thereof
• CPC Class Codes: A61F 2310/0097 Coating or prosthesis-covering structure made of pharmaceutical products, e.g. antibiotics
• CPC Class Codes: A61L 2430/38 for reconstruction of the spine, vertebrae or intervertebral discs
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/58 Materials at least partially resorbable by the body
• CPC Class Codes: B29C 41/14 Dipping a core B29C41/10 takes precedence
• CPC Class Codes: B29C 41/42 : Removing articles from moulds, cores or other substrates B29C33/444 and B29C37/0017 take precedence
• CPC Class Codes: C08L 71/02 : Polyalkylene oxides
• CPC Class Codes: C08L 75/04 : Polyurethanes

Abstract

A bioactive/biodegradable nucleus implant for repairing degenerated intervertebral discs that is inflated inside the nucleus space after the degenerated nucleus has been removed to re-pressurize the nuclear space within the intervertebral disc. The implant is inflated with a high molecular weight fluid, gel or combination of fluid and elastomer, preferably an under-hydrated HA hydrogel/growth factor mixture with or without host cells. The implant includes an internal, integral, self-sealing valve that allows one-way filling of the implant after it is placed within the disc, and is made from a material that allows fibrous in growth thereby stabilizing the implant. A variety of substances can be incorporated into the implant to promote healing, prevent infection, or arrest pain.

Claims

1. An implant for repairing an intervertebral disc, which disc comprises an annulus that substantially surrounds a nuclear space and is located between first and second adjacent vertebrae, said implant comprising:

an inflatable membrane;

said membrane having an internal chamber;

said membrane having an internal self-sealing fill valve located within the internal chamber;

said membrane being insertable in a collapsed configuration through a passageway formed across the annulus wall and into the nuclear space;

said membrane being adjustable within the nuclear space from the collapsed configuration to an inflated configuration with a geometry configured to substantially fill the nuclear space such that a first portion of the membrane is located adjacent the first vertebra, a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra;

wherein said internal self-sealing fill valve comprises internal opposing walls that are configured relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber; and

wherein said membrane in the inflated configuration within the nuclear space is configured to contribute substantial support to the disc under the compressive load between the adjacent vertebrae.

2. An implant as recited in claim 1, wherein said membrane comprises an elastomer.

3. An implant as recited in claim 2, wherein said elastomer is biodegradable.

4. An implant as recited in claim 2, wherein said elastomer comprises polyurethane.

5. An implant as recited in claim 4, wherein said polyurethane comprises aliphatic polycarbonate polyurethane.

6. An implant as recited in claim 1, wherein said chamber is filled with a hydrogel.

7. An implant as recited in claim 6, wherein said hydrogel comprises cross-linkable polyethylene glycol.

8. An implant as recited in claim 6, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

9. An implant as recited in claim 6, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

10. An implant as recited in claim 9, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

11. An implant for repairing an intervertebral disc, said disc having a nuclear space located between first and second adjacent vertebrae, comprising:

an inflatable membrane;

said membrane configured to be inserted in a nuclear space between the first and second adjacent vertebrae;

said membrane having an internal chamber;

said membrane being adjustable within the nuclear space from the collapsed configuration to an inflated configuration with a geometry configured to substantially fill the nuclear space such that a first portion of the membrane is located adjacent the first vertebra, a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

means for sealing a fill material within said chamber;

wherein said means for sealing a fill material is coupled to the internal chamber such that a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, seals said internal chamber.

12. An implant as recited in claim 11, wherein said means comprises an internal, self-sealing, fill-valve integral to said membrane.

13. An implant as recited in claim 11, wherein said membrane comprises an elastomer.

14. An implant as recited in claim 13, wherein said elastomer is biodegradable.

15. An implant as recited in claim 13, wherein said elastomer comprises polyurethane.

16. An implant as recited in claim 15, wherein said polyurethane comprises aliphatic polycarbonate polyurethane.

17. An implant as recited in claim 11, wherein said chamber is filled with a hydrogel.

18. An implant as recited in claim 17, wherein said hydrogel comprises cross-linkable polyethylene glycol.

19. An implant as recited in claim 17, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

20. An implant as recited in claim 17, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

21. An implant as recited in claim 20, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

22. An implant for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, elastic membrane;

said membrane being insertable into said disc in a collapsed configuration through a passageway formed in the disc and into a nuclear space between the first and second adjacent vertebrae;

said membrane having an internal chamber; and

said membrane having an internal self-sealing fill valve located within the internal chamber;

wherein said membrane is configured to be inflated within the nuclear space to substantially fill the nuclear space such that a first portion of the membrane is located adjacent the first vertebra, a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra;

wherein said internal self-sealing fill valve comprises internal opposing walls that are disposed relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber; and

wherein said membrane in the inflated configuration within the nuclear space is configured to contribute substantial support to the disc under the compressive load between the adjacent vertebrae.

23. An implant as recited in claim 22, wherein said membrane is biodegradable.

24. An implant as recited in claim 22, wherein said membrane comprises polyurethane.

25. An implant as recited in claim 24, wherein said polyurethane comprises aliphatic polycarbonate polyurethane.

26. An implant as recited in claim 22, wherein said chamber is filled with a hydrogel.

27. An implant as recited in claim 26, wherein said hydrogel comprises cross-linkable polyethylene glycol.

28. An implant as recited in claim 26, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

29. An implant as recited in claim 26, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

30. An implant as recited in claim 29, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

31. An implant for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, biodegradable, aliphatic polycarbonate polyurethane membrane;

said membrane configured to be installed between the adjacent vertebrae and inflated such that a first portion of the membrane contacts the first vertebrae, and a second portion of the membrane contacts a second vertebrae;

said membrane having an internal chamber; and

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

wherein said internal self-sealing fill valve comprises internal opposing walls in communication with said membrane such that the internal walls collapse as a result of a compressive load disposed on said internal chamber through the first and second adjacent vertebrae and resulting contact with said first and second membrane portions.

32. An implant as recited in claim 31, wherein said chamber is filled with a hydrogel.

33. An implant as recited in claim 32, wherein said hydrogel comprises cross-linkable polyethylene glycol.

34. An implant as recited in claim 32, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

35. An implant as recited in claim 32, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

36. An implant as recited in claim 35, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

37. An implant for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, biodegradable, aliphatic polycarbonate polyurethane membrane;

said membrane having an internal chamber filled with a hydrogel;

said membrane configured to be installed between the adjacent vertebrae and inflated so that a first portion of the membrane contacts the first vertebrae, and a second portion of the membrane contacts a second vertebrae; and

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

wherein said internal self-sealing fill valve comprises internal opposing walls in communication with said membrane such that the internal walls collapse as a result of a compressive load disposed on said internal chamber through the first and second adjacent vertebrae and resulting contact with said first and second membrane portions.

38. An implant as recited in claim 37, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

39. An implant as recited in claim 38, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

40. An implant for repairing an intervertebral disc, comprising:

an inflatable, biodegradable, aliphatic polycarbonate polyurethane membrane;

said membrane having an internal chamber filled with a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa) and a “

2-arm”

amine-specific electrophilic dimer;

said membrane having an integral, internal self-sealing fill valve.

41. An implant as recited in claim 40, wherein said material in said chamber is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

42. An implant system for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable membrane;

said membrane having an internal chamber;

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

said membrane configured for insertion into a nuclear space created by removing nucleus pulposus tissue in an intervertebral disc;

said nuclear space being bounded at least partially by said first and second adjacent vertebrae;

wherein said membrane is configured to be inflated within the nuclear space so that a first portion of the membrane is located adjacent the first vertebra, and a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

an annular buttress configured for placement in the annulus fibrosus of said intervertebral disc and retention of said membrane in said nuclear space;

wherein said internal self-sealing fill valve comprises internal opposing walls that are disposed relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber.

43. An implant system as recited in claim 42, wherein said buttress includes a plurality of pins configured for engaging said annulus fibrosus.

44. An implant system as recited in claim 42, wherein said membrane comprises an elastomer.

45. An implant system as recited in claim 44, wherein said elastomer is biodegradable.

46. An implant system as recited in claim 44, wherein said elastomer comprises polyurethane.

47. An implant system as recited in claim 46, wherein said polyurethane comprises aliphatic polycarbonate polyurethane.

48. An implant system as recited in claim 42, wherein said chamber is filled with a hydrogel.

49. An implant system as recited in claim 48, wherein said hydrogel comprises cross-linkable polyethylene glycol.

50. An implant system as recited in claim 48, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

51. An implant system as recited in claim 48, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

52. An implant system as recited in claim 51, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

53. An implant system for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable membrane;

said membrane having an internal chamber;

said membrane configured to cooperate with a means for sealing a fill material within said chamber;

said membrane configured for insertion into a nuclear space created by removing nucleus pulposus tissue in an intervertebral disc;

said nuclear space being bounded by adjacent vertebral endplates located on opposing ends of the intervertebral disc;

wherein said membrane is configured to be inflated within the nuclear space so that a first portion of the membrane is located adjacent the first vertebra, and a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

an annular buttress configured for placement in the annulus fibrosus of said intervertebral disc and retention of said membrane in said nuclear space

wherein said membrane and said means for sealing a fill material seal the internal chamber in response to a compressive load the first and second vertebrae, and thus between the first and second membrane portions.

54. An implant system as recited in claim 53, wherein said buttress includes a plurality of pins configured for engaging said annulus fibrosus.

55. An implant system as recited in claim 53, wherein said means comprises an internal, self-sealing, fill-valve integral to said membrane.

56. An implant system as recited in claim 53, wherein said membrane comprises an elastomer.

57. An implant system as recited in claim 56, wherein said elastomer is biodegradable.

58. An implant system as recited in claim 56, wherein said elastomer comprises polyurethane.

59. An implant system as recited in claim 58, wherein said polyurethane comprises aliphatic polycarbonate polyurethane.

60. An implant system as recited in claim 53, wherein said chamber is filled with a hydrogel.

61. An implant system as recited in claim 60, wherein said hydrogel comprises cross-linkable polyethylene glycol.

62. An implant system as recited in claim 60, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

63. An implant system as recited in claim 60, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

64. An implant system as recited in claim 63, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

65. An implant system for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, elastic membrane;

said membrane having an internal chamber;

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

said membrane configured for insertion into a nuclear space created by removing nucleus pulposus tissue in an intervertebral disc;

said nuclear space being bounded at least partially by said first and second adjacent vertebrae;

wherein said membrane is configured to be inflated within the nuclear space so that a first portion of the membrane is located adjacent the first vertebra, and a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

an annular buttress configured for placement in the annulus fibrosus of said intervertebral disc and retention of said membrane in said nuclear space;

wherein said internal self-sealing fill valve comprises internal opposing walls that are disposed relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber.

66. An implant system as recited in claim 65, wherein said buttress includes a plurality of pins configured for engaging said annulus fibrosus.

67. An implant system as recited in claim 65, wherein said membrane is biodegradable.

68. An implant system as recited in claim 65, wherein said membrane comprises polyurethane.

69. An implant system as recited in claim 68, wherein said polyurethane comprises aliphatic polycarbonate polyurethane.

70. An implant system as recited in claim 65, wherein said chamber is filled with a hydrogel.

71. An implant system as recited in claim 70, wherein said hydrogel comprises cross-linkable polyethylene glycol.

72. An implant system as recited in claim 70, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

73. An implant system as recited in claim 70, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

74. An implant system as recited in claim 73, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

75. An implant system for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, biodegradable, aliphatic polycarbonate polyurethane membrane;

said membrane having an internal chamber;

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

wherein said membrane and said internal self-sealing fill valve are a unitary piece of material;

said membrane configured for insertion into a nuclear space created by removing nucleus pulposus tissue in an intervertebral disc;

said nuclear space being bounded at least partially by said first and second adjacent vertebrae;

wherein said membrane is configured to be inflated within the nuclear space so that a first portion of the membrane is located adjacent the first vertebra, and a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

an annular buttress configured for placement in the annulus fibrosus of said intervertebral disc and retention of said membrane in said nuclear space;

wherein said internal self-sealing fill valve comprises internal opposing walls that are disposed relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber.

76. An implant system as recited in claim 75, wherein said buttress includes a plurality of pins configured for engaging said annulus fibrosus.

77. An implant system as recited in claim 75, wherein said chamber is filled with a hydrogel.

78. An implant system as recited in claim 77, wherein said hydrogel comprises cross-linkable polyethylene glycol.

79. An implant system as recited in claim 77, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

80. An implant system as recited in claim 77, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

81. An implant system as recited in claim 80, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

82. An implant system for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, biodegradable, aliphatic polycarbonate polyurethane membrane;

said membrane having an internal chamber filled with a hydrogel;

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

said membrane configured for insertion into a nuclear space created by removing nucleus pulposus tissue in an intervertebral disc;

said nuclear space being bounded at least partially by said first and second adjacent vertebrae;

wherein said membrane is configured to be inflated within the nuclear space so that a first portion of the membrane is located adjacent the first vertebra, and a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

an annular buttress configured for placement in the annulus fibrosus of said intervertebral disc and retention of said membrane in said nuclear space;

wherein said internal self-sealing fill valve comprises internal opposing walls that are disposed relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber.

83. An implant system as recited in claim 82, wherein said buttress includes a plurality of pins configured for engaging said annulus fibrosus.

84. An implant system as recited in claim 82, wherein said hydrogel comprises:

a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa); and

a “

2-arm”

amine-specific electrophilic dimer.

85. An implant system as recited in claim 84, wherein said hydrogel is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.

86. An implant system for repairing an intervertebral disc located between first and second adjacent vertebrae, comprising:

an inflatable, biodegradable, aliphatic polycarbonate polyurethane membrane;

said membrane having an internal chamber filled with a nucleophilic “

8-arm”

octomer (PEG-NH₂, MW 20 kDa) and a “

2-arm”

amine-specific electrophilic dimer;

said membrane having an integral, internal self-sealing fill valve located within the internal chamber;

wherein said membrane and said internal self-sealing fill valve are a unitary piece of material;

said membrane configured for insertion into a nuclear space created by removing nucleus pulposus tissue in an intervertebral disc;

said nuclear space being bounded at least partially by said first and second adjacent vertebrae;

wherein said membrane is configured to be inflated within the nuclear space so that a first portion of the membrane is located adjacent the first vertebra, and a second portion of the membrane located opposite the first portion is positioned adjacent the second vertebra; and

an annular buttress configured for placement in the annulus fibrosus of said intervertebral disc and retention of said membrane in said nuclear space;

wherein said internal self-sealing fill valve comprises internal opposing walls that are disposed relative to the membrane so as to collapse as a result of a compressive load between the first and second vertebrae, and thus between the first and second membrane portions, and thereby disposed on said internal chamber.

87. An implant system as recited in claim 86, wherein said buttress includes a plurality of pins configured for engaging said annulus fibrosus.

88. An implant system as recited in claim 86, wherein said material in said chamber is mixed with an additive selected from the group consisting essentially of chondroitin sulfate and hyaluronic acid.