Bone strip implants and method of making same

• US 20040249463A1
• Filed: 06/05/2003
• Published: 12/09/2004
• Est. Priority Date: 06/05/2003
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: McKay, William F., Simonton, T. Andrew, Reeves, Cary R., Bindseil, James J., Ray, Eddie F.
• Granted Patent: US 7,537,617 B2
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/82 for bone cerclage apparatus for manipulating wires or straps A61B17/8861; wires, bands or straps other than cerclage A61B17/842
• CPC Class Codes: A61B 17/842 Flexible wires, bands or straps A61B17/72, A61B17/82, A61B17/86 take precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/2875 Skull or cranium A61F2/2803 and A61F2/3099 take precedence
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• 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 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 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30057 made from both cortical and cancellous adjacent parts
• CPC Class Codes: A61F 2002/30059 differing in bone mineralization, e.g. made from both mineralized and demineralized adjacent parts
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30293 Cylindrical body made by spirally rolling up a sheet or a strip around itself
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30449 the adhesive being cement
• CPC Class Codes: A61F 2002/30461 sutured, ligatured or stitched
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30492 : using a locking pin
• CPC Class Codes: A61F 2002/30622 : Implant for fusing a joint or bone material
• CPC Class Codes: A61F 2002/30914 : Details of the mesh structure, e.g. disposition of the woven warp and weft wires
• CPC Class Codes: A61F 2002/30915 : made of a stack of bonded perforated sheets, grids or wire meshes
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/4649 : Bone graft or bone dowel harvest sites
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0029 : differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0036 : differing in thickness
• CPC Class Codes: A61F 2310/00365 : Proteins; Polypeptides; Degradation products thereof
• CPC Class Codes: A61L 2430/02 : for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 27/3608 : Bone, e.g. demineralised bone matrix [DBM], bone powder
• CPC Class Codes: A61L 27/365 : Bones
• CPC Class Codes: A61L 27/3683 : subjected to a specific treatment prior to implantation, e.g. decellularising, demineralising, grinding, cellular disruption/non-collagenous protein removal, anti-calcification, crosslinking, supercritical fluid extraction, enzyme treatment

Abstract

The present invention provides an implant for use in fusing adjacent bony structures. The implant comprises a plurality of bone pieces formed into at least one load bearing layer.

Claims

1. An implant for use in fusing adjacent bony structures, the implant comprising a plurality of elongate bone pieces formed into at least one load bearing layer.

2. The implant of claim 1 wherein the elongate bone pieces are interconnected by at least one interconnection mechanism selected from the group consisting of weaving, pinning, suturing, pressing, incorporating a binding agent, and cross-linking exposed collagen fibers.

3. The implant of claim 1 wherein the elongate bone pieces are interconnected by a biocompatible adhesive.

4. The implant of claim 3 wherein the adhesive comprises at least one adhesive selected from the group consisting of fibrin glue, cyanoacrylate, epoxy, polymethylmethacrylate, and gelatin based adhesives.

5. The implant of claim 1 wherein the elongate bone pieces are interconnected by at least one binding agent selected from the group consisting of settable ceramics, calcium carbonate, calcium phosphate, apatite, hydroxyapatite, and plaster.

6. The implant of claim 1 wherein the elongate bone pieces further comprise exposed collagen and the exposed collagen of adjacent pieces is crosslinked to interconnect the elongate bone pieces.

7. The implant of claim 1 wherein at least some of the elongate bone pieces further comprise holes formed therethrough and a flexible, elongate, biocompatible connecter, the connector being threaded through the holes to interconnect the pieces.

8. The implant of claim 7 wherein the connector comprises at least one connector selected from the group consisting of elongate pieces of body tissue and sutures.

9. The implant of claim 7 wherein the connector comprises at least one material selected from the group consisting of pericardium, demineralized bone, fascia, cartilage, tendon, ligament, skin, collagen, elastin, reticulum, intestinal submucosa, metal, resorbable polymer, and nonresorbable polymer.

10. The implant of claim 1 wherein the elongate bone pieces are woven together.

11. The implant of claim 10 wherein at least some of the elongate bone pieces are at least partially demineralized to increase their flexibility.

12. The implant of claim 11 wherein the elongate bone pieces are woven with a portion of the pieces being oriented in a first direction and a portion of the pieces being oriented in a second direction angled relative to the first direction, the pieces lying in the first direction being at least partially demineralized to increase their flexibility.

13. The implant of claim 12 wherein the elongate bone pieces lying in the second direction comprise fully mineralized bone.

14. The implant of claim 10 wherein at least some of the elongate bone pieces are individually at least partly demineralized at one or more spaced apart discrete portions such that each individual piece comprises a plurality of mineralized segments separated by relatively more flexible demineralized segments.

15. The implant of claim 1 wherein the individual pieces of bone have less than a predetermined minimum load bearing capacity and the combined pieces form an implant that achieves a predetermined load bearing capacity greater than the predetermined minimum load bearing capacity.

16. The implant of claim 1 wherein the individual pieces of bone have a predetermined geometry outside of a predetermined standard associated with a unitary implant and the combined pieces form an assembled implant that achieves the predetermined geometry.

17. The implant of claim 1 wherein the individual elongate pieces of bone comprise an elongate cortical bone layer running along substantially the entire length of the piece.

18. The implant of claim 17 further comprising a predetermined cortical layer thickness less than a predetermined minimum thickness for an integral bone implant

19. The implant of claim 17 wherein the individual elongate pieces of bone further comprise a cancellous bone layer adjacent to the cortical bone layer along at least a portion of the length of the piece.

20. The implant of claim 1 further comprising a layer axis substantially normal to the layer and a load bearing axis along which load is applied to the implant from the adjacent bony structures, the layer axis being substantially parallel to the load bearing axis.

21. The implant of claim 1 further comprising a layer axis substantially normal to the layer and a load bearing axis along which load is applied to the implant from the adjacent bony structures, the layer axis being substantially perpendicular to the load bearing axis.

22. The implant of claim 1 wherein each of the plurality of elongate bone pieces has a longitudinal axis and the plurality of elongate bone pieces are arranged in the layer with their longitudinal axes being substantially parallel.

23. The implant of claim 22 further comprising a load bearing axis along which load is applied to the implant from the adjacent bony structures, the longitudinal axes of the plurality of bone pieces being substantially perpendicular to the load bearing axis.

24. The implant of claim 22 further comprising a load bearing axis along which load is applied to the implant from the adjacent bony structures, the longitudinal axes of the plurality of bone pieces being substantially parallel to the load bearing axis.

25. The implant of claim 1 comprising a plurality of layers, each layer comprising a plurality of elongate bone pieces.

26. The implant of claim 25 wherein the plurality of layers comprises a plurality of radial layers formed by rolling a single layer into a substantially cylindrical shape.

27. The implant of claim 26 wherein each layer comprises a plurality of elongate bone pieces woven together, the implant being formed by first weaving the elongate bone pieces to form a single layer and then rolling the single layer into a substantially cylindrical shape.

28. The implant of claim 25 wherein the plurality of layers comprises a single layer folded back on itself at least once to form the plurality of layers.

29. The implant of claim 28 wherein each layer comprises a plurality of elongate bone pieces woven together, the implant being formed by first weaving the elongate bone pieces to form a single layer and then folding the layer back on itself one or more time.

30. The implant of claim 25 wherein the plurality of layers comprises a stack of individual discrete layers.

31. The implant of claim 30 wherein each layer comprises a plurality of elongate bone pieces woven together.

32. The implant of claim 25 further comprising one or more interconnection mechanisms securing the layers together.

33. The implant of claim 32 further comprising at least one interconnection mechanism selected from the group consisting of weaving, pinning, suturing, pressing, incorporating a binding agent, and cross-linking exposed collagen fibers.

34. The implant of claim 32 wherein the layers are interconnected by a biocompatible adhesive binding agent.

35. The implant of claim 34 wherein the adhesive comprises at least one adhesive selected from the group consisting of fibrin glue, cyanoacrylate, epoxy, polymethylmethacrylate, and gelatin based adhesives.

36. The implant of claim 32 wherein the layers are interconnected by at least one binding agent selected from the group consisting of settable ceramics, calcium carbonate, calcium phosphate, apatite, hydroxyapatite, and plaster.

37. The implant of claim 32 wherein the layers further comprise exposed collagen and the exposed collagen of adjacent layers is crosslinked to interconnect the layers.

38. The implant of claim 32 further comprising an elongate biocompatible connecter, the connector being threaded through the layers to interconnect the layers.

39. The implant of claim 38 wherein the connector comprises at least one connector selected from the group consisting of elongate pieces of body tissue and sutures.

40. The implant of claim 38 wherein the connector comprises at least one material selected from the group consisting of pericardium, demineralized bone, fascia, cartilage, tendon, ligament, skin, collagen, elastin, reticulum, intestinal submucosa, metal, resorbable polymer, and nonresorbable polymer.

41. The implant of claim 25 further comprising one or more openings through the implant to facilitate the fusion of the adjacent bony structures.

42. The implant of claim 41 further comprising a bone growth promoting material within the one or more openings.

43. The implant of claim 42 wherein the bone growth promoting material comprises at least one material selected from the group comprising bone derived growth factors, osteogenic proteins, bone morphogenic proteins, human recombinant bone morphogenic proteins, LIM mineralization proteins, bone paste, bone chips, demineralized bone, hydroxyapatite, hormones, and platelet derived growth factor.

44. The implant of claim 25 wherein the plurality of layers overlie one another along a layer axis normal to the layers, the implant further comprising a load bearing axis along which load is applied to the implant from the adjacent bony structures, the layer axis being substantially parallel to the load bearing axis.

45. The implant of claim 44 wherein the layers overlie one another radially in a wound spiral construct.

46. The implant of claim 44 wherein the layers comprise a single layer folded back on itself one or more times.

47. The implant of claim 44 wherein the layers comprise a stack of individual discrete layers.

48. The implant of claim 25 wherein the plurality of layers overlie one another along a layer axis substantially normal to the layers, the implant further comprising a load bearing axis along which load is applied to the implant from the adjacent bony structures, the layer axis being substantially perpendicular to the load bearing axis.

49. The implant of claim 48 wherein the layers overlie one another radially in a wound spiral construct.

50. The implant of claim 48 wherein the layers comprise a single layer folded back on itself one or more times.

51. The implant of claim 48 wherein the layers comprise a stack of individual discrete layers.

52. The implant of claim 1 further comprising a fixation device attached to said adjacent bony structures to limit relative motion therebetween.

53. An implant for use in fusing adjacent bony structures, the implant comprising a plurality of layers, each layer comprising a plurality of elongate bone pieces.

54. The implant of claim 53 wherein the layers overlie one another radially in a wound spiral construct.

55. The implant of claim 53 wherein the layers comprise a single layer folded back on itself one or more times.

56. The implant of claim 53 wherein the layers comprise a stack of individual discrete layers.

57. The implant of claim 53 further comprising at least one interconnection mechanism selected from the group consisting of weaving, pinning, suturing, pressing, incorporating a binding agent, and cross-linking exposed collagen fibers.

58. The implant of claim 53 further comprising a fixation device attached to said adjacent bony structures to limit relative motion therebetween.

59. A method for use in fusing adjacent bony structures, the method comprising the steps of:

combining a plurality of layers to form a layered implant, each layer comprising a plurality of elongate bone pieces; and

positioning the implant between adjacent bony structures in load bearing relationship.

60. The method of claim 59 wherein the step of combining further comprises the step of interconnecting the plurality of elongate bone pieces in the individual layers.

61. The method of claim 59 wherein the plurality of layers overlie one another along a layer axis substantially normal to the layers, and the step of positioning the implant comprises positioning the implant with the layer axis substantially parallel to a load bearing axis along which load is applied to the implant from the adjacent bony structures.

62. The method of claim 59 wherein the plurality of layers overlie one another along a layer axis substantially normal to the layers, and the step of positioning the implant comprises positioning the implant with the layer axis substantially perpendicular to a load bearing axis along which load is applied to the implant from the adjacent bony structures.

63. The method of claim 59 further comprising the step of attaching a fixation device to said adjacent bony structures to limit relative motion therebetween.

64. An implant for use in fusing adjacent bony structures, the implant comprising:

a plurality of elongate bone pieces formed into at least one load bearing layer, at least some of the elongate bone pieces further comprising holes formed therethrough; and

a flexible, elongate, biocompatible connecter, the connector being threaded through the holes to interconnect the pieces.

65. The implant of claim 64 wherein the connector comprises at least one connector selected from the group consisting of elongate pieces of body tissue and sutures.

66. The implant of claim 64 wherein the connector comprises at least one material selected from the group consisting of pericardium, demineralized bone, fascia, cartilage, tendon, ligament, skin, collagen, elastin, reticulum, intestinal submucosa, metal, resorbable polymer, and nonresorbable polymer.

67. The implant of claim 64 further comprising a fixation device attached to said adjacent bony structures to limit relative motion therebetween.

68. An implant for use in fusing adjacent bony structures, the implant comprising a plurality of elongate bone pieces formed into at least one load bearing layer, the elongate bone pieces being woven together.

69. The implant of claim 68 wherein at least some of the elongate bone pieces are at least partially demineralized to increase their flexibility.

70. The implant of claim 69 wherein the elongate bone pieces are woven with a portion of the pieces being oriented in a first direction and a portion of the pieces being oriented in a second direction angled relative to the first direction, the pieces lying in the first direction being at least partially demineralized to increase their flexibility.

71. The implant of claim 70 wherein the elongate bone pieces lying in the second direction comprise fully mineralized bone.

72. The implant of claim 68 wherein at least some of the elongate bone pieces are individually at least partly demineralized at one or more spaced apart discrete portions such that the piece comprises a plurality of mineralized segments separated by relatively more flexible demineralized segments.

73. The implant of claim 68 further comprising a fixation device attached to said adjacent bony structures to limit relative motion therebetween.