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1. WO1996040014 - REINFORCED POROUS SPINAL IMPLANTS

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

WHAT IS CLAIMED:

1. A spinal implant for engagement between vertebrae, comprising:
a body having two opposite faces and an outer surface disposed between said two faces, said body including a porous, biocompatible material for permitting tissue ingrowth therethrough, said body being sized and configured for engagement between two vertebrae; and
a sleeve disposed around said outer surface of said body, said sleeve including a second material relatively stronger under compressive loads than said porous, biocompatible material .

2. The implant of claim 1 wherein said sleeve defines a plurality of apertures therethrough in communication with
said outer surface of said body for bone ingrowth.

3. The implant of claim 2 wherein said apertures are generally circular.

4. The implant of claim 2 wherein said apertures are generally oval.

o 5. The implant of claim 2 wherein said apertures are generally diamond-shaped.

6. The implant of claim 2 wherein said apertures are generally rectangular.

7. The implant of claim 1 wherein:
said sleeve includes an inner surface for contacting said outer surface of said body, said inner surface of said sleeve defining a chamber;
said sleeve being formed of a temperature responsive material such that said chamber has a first inner dimension that is slightly larger than an outer dimension of said body when said sleeve is in a heated state to slidably receive said body therein; and
said chamber has a second inner dimension that is
slightly smaller than said body when said sleeve is in a cooled state to thereby clamp said body therein.

8. The implant of claim 1 wherein said sleeve has a height less than a height of said outer surface to permit contact of said opposite faces with endplates of the
corresponding vertebrae when the implant is implanted between the vertebrae.

9. The implant of claim 1, wherein said sleeve includes: an inferior end and an opposite superior end; and
rigid teeth disposed at each of said inferior and
superior ends of said sleeve for engaging the implant to the vertebral bodies.

10. The implant of claim 1, wherein:
said sleeve includes an inferior end and an opposite superior end; and
each of said inferior and superior ends of said sleeve includes a roughened surface for engaging the implant to the vertebral bodies.

11. The implant of claim 1 wherein said body is
cylindrical and said sleeve is a hollow cylinder.

12. The implant of claim 1 wherein said opposite faces of said body each have a size and shape corresponding to the shape of a vertebral endplate.

13. The implant of claim 1 wherein said sleeve has an outer shape approximating the shape of a vertebral endplate.

14. The implant of claim 1 wherein said sleeve is composed of a metal material.

15. The implant of claim 14 wherein said metal material includes a metal selected from the group consisting of tantalum, niobium, hafnium, tungsten and alloys thereof.

16. The implant of claim 15 wherein said metal material is a tantalum foam.

17. The implant of claim 14 wherein said sleeve is composed of a metal material including a metal selected from the group consisting of titanium, titanium-vanadium-aluminum alloy, cobalt-chromium alloy, cobalt-chromium-molybdenum alloy, cobalt-nickle-chromium-molybdenum alloy and
biocompatible stainless steel.

18. The implant of claim 17 wherein said biocompatible stainless steel is 316 LVM stainless steel.

19. The implant of claim 17 wherein said metal sleeve includes titanium.

20. The implant of claim 1 wherein said biocompatible material is a ceramic material.

21. The implant of claim 20 wherein said ceramic is a bioactive osteoconductive ceramic.

22. The implant of claim 20 wherein said biocompatible material is a collagen-ceramic composite.

23. The implant of claim 20 wherein said biocompatible material is a ceramic-growth factor composite.

24. The implant of claim 23 wherein said biocompatible material is a ceramic-bone morphogenic protein composite.

25. The implant of claim 20 wherein said ceramic is a calcium phosphate ceramic.

26. The implant of claim 20 wherein said biocompatible material is a biphasic ceramic.

27. The implant of claim 20 wherein said ceramic
material is selected from the group consisting of
hydroxyapatite, tricalcium phosphate, tetracalcium phosphate, α calcium pyrophosphate, β calcium pyrophosphate and
mixtures thereof.

28. The implant of claim 27 wherein said ceramic is a biphasic calcium phosphate ceramic.

29. The implant of claim 28 wherein said ceramic is a hydroxyapatite/tricalcium phosphate ceramic.

30. The implant of claim 29 wherein said ceramic includes less than about 90% hydroxyapatite by weight.

31. The implant of claim 30 wherein said ceramic includes less than about 75% hydroxyapatite by weight.

32. The implant of claim 31 wherein said ceramic includes about 50% hydroxyapatite by weight.

33. The implant of claim 32 wherein said ceramic includes less than about 25% hydroxyapatite by weight.

34. The implant of claim 1 wherein said biocompatible material has a porosity of at least about 30%.

35. The implant of claim 34 wherein said biocompatible material has a porosity of at least about 50%.

36. The implant of claim 35 wherein said biocompatible material has a porosity of at least about 70%.

37. The implant of claim 32 wherein said ceramic has a porosity of at least about 40%.

38. The implant of claim 37 wherein said ceramic has a porosity of at least about 50%.

39. The implant of claim 20 wherein said ceramic has a mean pore size of about 200 to about 700 microns.

40. The implant of claim 20 wherein said ceramic has a mean pore size of about 300 to about 600 microns.

41. The implant of claim 38 wherein said ceramic has a mean pore size of about 400 microns.

42. The implant of claim 1 wherein said implant has an ASTM C-773 compressive strength of at least 7.1 MPa.

43. The implant of claim 41 wherein said implant has a compressive strength of at least 20 MPa.

44. The implant of claim 43 wherein said implant has a compressive strength of at least 40 MPa.

45. An interbody fusion device, comprising:
a body having an outer surface and a height approximating the height of a human disc space, said body including a porous, biocompatible material for permitting tissue ingrowth therethrough; and
a sleeve engaged to said outer surface of said body, said sleeve including a material relatively stronger under
compressive loads than said biocompatible material.

46. The device of claim 45, further comprising:
attaching means for attaching said sleeve to the
endplates of the adjacent vertebral bodies.

47. The device of claim 46 wherein:
said sleeve includes an inferior end and a superior end; and
said attaching means includes teeth disposed at said superior end and said inferior end of said sleeve.

48. The device of claim 46 wherein:
said sleeve includes an inferior end and a superior end; and
said attaching means includes roughened surfaces defined on said superior end and said inferior end of said sleeve.

49. The device of claim 45 wherein said sleeve defines a plurality of apertures therethrough in communication with said outer surface of said body for promoting bone ingrowth.

50. The implant of claim 45 wherein said sleeve is composed of a metal material.

51. The implant of claim 50 wherein said metal material includes a metal selected from the group consisting of
tantalum, niobium, hafnium, tungsten and alloys thereof.

52. The implant of claim 51 wherein said metal material is a tantalum foam.

53. The device of claim 50 wherein said metal material includes titanium.

54. The device of claim 45 wherein said body has a kidney-shaped cross-section to conform to the shape of
vertebral endplates.

55. The device of claim 45 wherein said height of said body is slightly larger than the height of a human disc space,

56. The device of claim 45 wherein said body is
configured to approximate a size and shape of a nucleus pulposus of a natural intervertebral disc

57. The implant of claim 45 wherein said biocompatible material is a ceramic material.

58. The implant of claim 57 wherein said biocompatible material is a biphasic calcium phosphate ceramic.

59. The implant of claim 58 wherein said biocompatible material is a hydroxyapatite/tricalcium phosphate ceramic.

60. The implant of claim 57 wherein said ceramic has a porosity of at least about 50%.

61. The implant of claim 60 wherein said ceramic has a porosity of at least about 70%.

62. The implant of claim 57 wherein said ceramic has a mean pore size of about 200 to about 700 microns.

63. The implant of claim 62 wherein said ceramic has a mean pore size of about 300 to about 600 microns.

64. The implant of claim 63 wherein said ceramic has a mean pore size of about 400 microns.

65. A vertebral body replacement device for use in restoring the space left by the removal of a defective spinal element located between adjoining healthy vertebral bodies, comprising:
a body having an outer surface and configured to be locatable within the space between the adjoining vertebral bodies, said body including a porous, biocompatible material; and
a sleeve disposed around said outer surface of said body, said sleeve composed of a material relatively stronger under compressive loads than said biocompatible material.

66. The device of claim 65, further comprising:
attaching means for attaching said metal sleeve to endplates of said adjoining vertebral bodies.

67. The device of claim 65 wherein:
said sleeve includes an inferior end and a superior end; and
said attaching means includes teeth disposed at said superior end and said inferior end of said metal sleeve.

68. The device of claim 65 wherein
said sleeve includes an inferior end and a superior end; and said attaching means includes roughened surfaces defined on said superior end and said inferior end of said sleeve.

69. The device of claim 64 wherein said sleeve defines a plurality of apertures therethrough in communication with said outer surface of said body for promoting bone ingrowth.

70. The implant of claim 65 wherein said sleeve is composed of a metal material.

71. The implant of claim 70 wherein said metal material includes a metal selected from the group consisting of tantalum, niobium, hafnium, tungsten and alloys thereof.

72. The implant of claim 71 wherein said metal material is a tantalum foam.

73. The device of claim 70 wherein said metal material includes titanium.

74. The device of claim 65 wherein said body is sized and shaped to fit snugly within a space defined by the endplates and annuli of the adjacent vertebral bodies.

75. The device of claim 65 wherein said biocompatible material is a ceramic material.

76. The device of claim 75 wherein said biocompatible material is a biphasic calcium phosphate ceramic.

77. The device of claim 76 wherein said biocompatible material is a hydroxyapatite/tricalcium phosphate ceramic.

78. The implant of claim 75 wherein said ceramic has a porosity of at least about 50%.

79. The implant of claim 78 wherein said ceramic has a porosity of at least about 70%.

80. The implant of claim 75 wherein said ceramic has a mean pore size of about 200 to about 700 microns.

81. The implant of claim 80 wherein said ceramic has a mean pore size of about 300 to about 600 microns.

82. The implant of claim 81 wherein said ceramic has a mean pore size of about 400 microns.

83. The implant of claim 45 wherein said body is configured to approximate the size and shape of an
intervertebral disc.

AMENDED CLAIMS
[received by the International Bureau on 4 November 1996 (04.11.96); original claims 1,8,18,45,56 and 65 amended; remaining claims
unchanged (8 pages)]

1. A spinal implant for engagement between
vertebrae, comprising:
a load bearing body having two opposite faces and an outer surface disposed between said two faces, said body including a porous, biocompatible, material for permitting tissue ingrowth therethrough, said body being sized and configured for engagement between two vertebrae; and
a sleeve disposed around said outer surface of said body, said sleeve including a second material relatively stronger under compressive loads than said porous,
biocompatible material.

2. The implant of claim 1 wherein said sleeve defines a plurality of apertures therethrough in
communication with said outer surface of said body for bone ingrowth.

3. The implant of claim 2 wherein said apertures are generally circular.

4. The implant of claim 2 wherein said apertures are generally oval.

5. The implant of claim 2 wherein said apertures are generally diamond-shaped.

6. The implant of claim 2 wherein said apertures are generally rectangular.

7. The implant of claim 1 wherein:
said sleeve includes an inner surface for contacting said outer surface of said body, said inner surface of said sleeve defining a chamber;
said sleeve being formed of a temperature responsive material such that said chamber has a first inner dimension that is slightly larger than an outer dimension of said body when said sleeve is in a heated state to slidably receive said body therein; and
said chamber has a second inner dimension that is
slightly smaller than said body when said sleeve is in a cooled state to thereby clamp said body therein.

8. A spinal implant for engagement between vertebrae, comprising :
a body having two opposite faces and an outer surface disposed between said two faces, said body including a
porous, biocompatible material for permitting tissue ingrowth therethrough, said body being sized and configured for
engagement between two vertebrae; and
a sleeve disposed around said outer surface of said body, said sleeve including a second material relatively stronger under compressive loads than said porous, biocompatible material, wherein said sleeve has a height less than a height of said outer surface to permit contact of said opposite faces with endplates of the corresponding vertebrae when the implant is implanted between the vertebrae.

9. The implant of claim 1, wherein said sleeve includes: an inferior end and an opposite superior end; and
rigid teeth disposed at each of said inferior and
superior ends of said sleeve for engaging the implant to the vertebral bodies.

10. The implant of claim 1, wherein:
said sleeve includes an inferior end and an opposite superior end; and
each of said inferior and superior ends of said sleeve includes a roughened surface for engaging the implant to the vertebral bodies.

11. The implant of claim 1 wherein said body is
cylindrical and said sleeve is a hollow cylinder.

12. The implant of claim 1 wherein said opposite faces of said body each have a size and shape corresponding to the shape of a vertebral endplate.

13. The implant of claim 1 wherein said sleeve has an outer shape approximating the shape of a vertebral endplate.

14. The implant of claim 1 wherein said sleeve is composed of a metal material.

15. The implant of claim 14 wherein said metal material includes a metal selected from the group consisting of tantalum, niobium, hafnium, tungsten and alloys thereof.

16. The implant of claim 15 wherein said metal material is a tantalum foam.

17. The implant of claim 14 wherein said sleeve is composed of a metal material including a metal selected from the group consisting of titanium, titanium-vanadium-aluminum alloy, cobalt-chromium alloy, cobalt-chromium-molybdenum alloy, cobalt-nickle-chromium-molybdenum alloy and
biocompatible stainless steel.

18. The implant of claim 17 wherein said metal is biocompatible stainless steel.

19. The implant of claim 17 wherein said metal sleeve includes titanium.

20. The implant of claim 1 wherein said biocompatible material is a ceramic material.

21. The implant of claim 20 wherein said ceramic is a bioactive osteoconductive ceramic.

22. The implant of claim 20 wherein said biocompatible material is a collagen-ceramic composite.

23. The implant of claim 20 wherein said biocompatible material is a ceramic-growth factor composite.

24. The implant of claim 23 wherein said biocompatible material is a ceramic-bone morphogenic protein composite.

25. The implant of claim 20 wherein said ceramic is a calcium phosphate ceramic.

26. The implant of claim 20 wherein said biocompatible material is a biphasic ceramic.

27. The implant of claim 20 wherein said ceramic
material is selected from the group consisting of
hydroxyapatite, tricalcium phosphate, tetracalcium phosphate, α calcium pyrophosphate, β calcium pyrophosphate and
mixtures thereof.

28. The implant of claim 27 wherein said ceramic is a biphasic calcium phosphate ceramic.

29. The implant of claim 28 wherein said ceramic is a hydroxyapatite/tricalcium phosphate ceramic.

30. The implant of claim 29 wherein said ceramic
includes less than about 90% hydroxyapatite by weight.

31. The implant of claim 30 wherein said ceramic
includes less than about 75% hydroxyapatite by weight.

32. The implant of claim 31 wherein said ceramic includes about 50% hydroxyapatite by weight.

33. The implant of claim 32 wherein said ceramic includes less than about 25% hydroxyapatite by weight.

34. The implant of claim 1 wherein said biocompatible material has a porosity of at least about 30%.

35. The implant of claim 34 wherein said biocompatible material has a porosity of at least about 50%.

36. The implant of claim 35 wherein said biocompatible material has a porosity of at least about 70%.

37. The implant of claim 32 wherein said ceramic has a porosity of at least about 40%.

38. The implant of claim 37 wherein said ceramic has a porosity of at least about 50%.

39. The implant of claim 20 wherein said ceramic has a mean pore size of about 200 to about 700 microns.

40. The implant of claim 20 wherein said ceramic has a mean pore size of about 300 to about 600 microns.

41. The implant of claim 38 wherein said ceramic has a mean pore size of about 400 microns.

42. The implant of claim 1 wherein said implant has an ASTM C-773 compressive strength of at least 7.1 MPa.

43. The implant of claim 41 wherein said implant has a compressive strength of at least 20 MPa.

44. The implant of claim 43 wherein said implant has a compressive strength of at least 40 MPa.

45. An interbody fusion device, comprising:
a load bearing body having an outer surface and a height approximating the height of a human disc space, said body including a porous, biocompatible material for permitting tissue ingrowth therethrough; and
a sleeve engaged to said outer surface of said body, said sleeve including a material relatively stronger under compressive loads than said biocompatible material.

46. The device of claim 45, further comprising:
attaching means for attaching said sleeve to the
endplates of the adjacent vertebral bodies.

47. The device of claim 46 wherein:
said sleeve includes an inferior end and a superior end; and
said attaching means includes teeth disposed at said superior end and said inferior end of said sleeve.

48. The device of claim 46 wherein:
said sleeve includes an inferior end and a superior end; and
said attaching means includes roughened surfaces defined on said superior end and said inferior end of said sleeve.

49. The device of claim 45 wherein said sleeve defines a plurality of apertures therethrough in communication with said outer surface of said body for promoting bone ingrowth.

50. The implant of claim 45 wherein said sleeve is composed of a metal material.

51. The implant of claim 50 wherein said metal material includes a metal selected from the group consisting of
tantalum, niobium, hafnium, tungsten and alloys thereof.

52. The implant of claim 51 wherein said metal material is a tantalum foam.

53. The device of claim 50 wherein said metal material includes titanium.

54. The device of claim 45 wherein said body has a kidney-shaped cross-section to conform to the shape of
vertebral endplates.

55. The device of claim 45 wherein said height of said body is slightly larger than the height of a human disc space.

56. The device of claim 45 wherein said body is
configured to approximate a size and shape of a nucleus pulposus of a natural intervertebral disc.

57. The implant of claim 45 wherein said biocompatible material is a ceramic material.

58. The implant of claim 57 wherein said biocompatible material is a biphasic calcium phosphate ceramic.

59. The implant of claim 58 wherein said biocompatible material is a hydroxyapatite/tricalcium phosphate ceramic.

60. The implant of claim 57 wherein said ceramic has a porosity of at least about 50%.

61. The implant of claim 60 wherein said ceramic has a porosity of at least about 70%.

62. The implant of claim 57 wherein said ceramic has a mean pore size of about 200 to about 700 microns.

63. The implant of claim 62 wherein said ceramic has a mean pore size of about 300 to about 600 microns.

64. The implant of claim 63 wherein said ceramic has a mean pore size of about 400 microns.

65. A vertebral body replacement device for use in restoring the space left by the removal of a defective spinal element located between adjoining healthy vertebral bodies, comprising:
a load bearing body having an outer surface and
configured to be locatable within the space between the adjoining vertebral bodies, said body including a porous, biocompatible material; and
a sleeve disposed around said outer surface of said body, said sleeve composed of a material relatively stronger under compressive loads than said biocompatible material.

66. The device of claim 65, further comprising:
attaching means for attaching said metal sleeve to endplates of said adjoining vertebral bodies.

67. The device of claim 65 wherein:
said sleeve includes an inferior end and a superior end; and
said attaching means includes teeth disposed at said superior end and said inferior end of said metal sleeve.

68. The device of claim 65 wherein
said sleeve includes an inferior end and a superior end; and