Shaped osteochondral grafts and methods of using same

• US 20060247790A1
• Filed: 04/30/2005
• Published: 11/02/2006
• Est. Priority Date: 04/30/2005
• Status: Abandoned Application

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: McKay, William F.
• Application Number:
  US11/120,136
• Publication Number:
  US 20060247790A1
• Time in Patent Office: Days
• US Class Current: 623/23.440
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2002/30004 the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/3013 figure-"8"- or hourglass-shaped
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30171 rosette- or star-shaped
• CPC Class Codes: A61F 2002/30179 X-shaped
• CPC Class Codes: A61F 2002/30228 Cylinders of elliptical or oval basis
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30759 Mosaicplasty, i.e. using a plurality of individual cartilage plugs for filling a substantial cartilage defect
• CPC Class Codes: A61F 2002/30764 Cartilage harvest sites
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0004 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/001 : Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0028 : Shapes in the form of latin or greek characters
• CPC Class Codes: A61F 2230/005 : Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2250/0014 : having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

Described are plug grafts and in particular embodiments osteochondral plug grafts and grafting methods which utilize unique plug geometries and cooperative graft/host tissue interfaces to improve stability of grafted plugs within host tissue. Embodiments of the invention include harvested osteochondral or synthetic plug grafts having bore geometries other than circular cylinders and which are implantable in correspondingly prepared host sites to resist rotation and improve stability.

Claims

1. A method for repairing articular cartilage in a patient, comprising:

implanting at least one osteochondral plug graft at an articular cartilage site in the patient;

said plug graft comprising a cartilage layer attached to an underlying body of bone;

said body of bone, as implanted, comprising a bone sidewall positioned adjacent to a bone surface;

said bone sidewall and said bone surface together configured to provide a mechanical interlock to resist rotation of the implanted osteochondral plug graft.

2. The method of claim 1, wherein the bone surface is a surface of an adjacent osteochondral plug graft.

3. The method of claim 1, wherein the bone surface is a surface of bone of the patient.

4. The method of claim 1, wherein the body of bone has at least a portion having a polygonal cross-section.

5. The method of claim 4, wherein the articular cartilage site includes a hole having a polygonal cross-section corresponding to that of the body of bone, and wherein the body of bone is received in said hole.

6. The method of claim 5, wherein the polygonal cross-section is a rectangle.

7. The method of claim 6, wherein the polygonal cross section is a square.

8. The method of claim 1, wherein the body of bone has at least a portion having a multi-lobed cross section.

12. The method of claim 8, wherein the cross section includes from 2 to 6 circular arcs.

13. The method of claim 12, also comprising preparing the articular cartilage site for receipt of the osteochondral graft by creating a void in subchondral bone of the site, the void having a periphery defined by multiple overlapping right circular cylinders.

16. The method of claim 1, wherein the body of bone includes at least a portion having an oval-shaped cross section.

17. The method of claim 16, wherein the articular cartilage site is prepared to have an oval-shaped opening corresponding to the oval-shaped cross section of the body of bone, and wherein the at least a portion of the body of bone having an oval-shaped cross section is received in said oval-shaped opening.

18. The method of claim 1, wherein said sidewall and said bone surface further provide an interference fit against one another.

23. The method of claim 1, also comprising administering an osteogenic protein to the articular cartilage site.

24. The method of claim 23, wherein the osteogenic protein is a bone morphogenic protein (BMP).

25. The method of claim 24, wherein the BMP comprises recombinant human BMP-2.

9. (canceled)

10. (canceled)

11. (canceled)

14. (canceled)

15. (canceled)

19. (canceled)

20. (canceled)

21. (canceled)

22. (canceled)

26. (canceled)

27. (canceled)

28. A method for repairing an articular cartilage site in a patient, comprising:

implanting at least one plug body at an articular cartilage site in the patient;

said plug body, as implanted, comprising a sidewall positioned adjacent to a contact surface, said contact surface provided by subchondral bone of the patient and/or a surface of an adjacent plug body;

said sidewall and contact surface together configured to provide a mechanical interlock to resist rotation of the implanted plug body.

29. An osteochondral graft configured for stable implantation within a prepared surgical opening in subchondral bone of a patient at an articular cartilage site, the surgical opening having a three-dimensional contour other than a circular cylinder, the osteochondral graft comprising:

an osteochondral graft plug having a cartilage cap and a body of bone attached to the cartilage cap;

said body of bone including a stabilizing portion for receipt within the surgical opening;

said stabilizing portion of said body of bone presenting a three-dimensional contour other than a circular cylinder and configured for mated receipt within the surgical opening to provide a mechanical interlock against rotation.

30. The osteochondral graft of claim 29, wherein the surgical opening and the stabilizing portion have corresponding polygonal cross sections.

31. The osteochondral graft of claim 30, wherein the polygonal cross-sections are rectangular.

33. The osteochondral graft of claim 29, wherein the surgical opening and the stabilizing portion have corresponding multi-lobed cross sections.

34. The osteochondral graft of claim 33, wherein the cross sections are defined by multiple intersecting circular arcs.

39. The osteochondral graft of claim 29, wherein the surgical opening and stabilizing portion have corresponding ovate cross sections.

40. The osteochondral graft of claim 29, wherein said stabilizing portion is further sized and configured to provide an interference fit when received in said surgical opening.

41. The osteochondral graft of claim 29 wherein the patient is a human, and wherein the osteochondral graft is effectively configured to withstand biomechanical loads experienced by a human knee.

45. The osteochondral graft of claim 29, also comprising an osteogenic protein carried by said body of bone.

46. The osteochondral graft of claim 45, wherein the osteogenic protein is a bone morphogenic protein (BMP).

47. The osteochondral graft of claim 46, wherein the BMP comprises recombinant human BMP-2.

32. (canceled)

35. (canceled)

36. (canceled)

37. (canceled)

38. (canceled)

42. (canceled)

43. (canceled)

44. (canceled)

48. A medical implant configured for stable implantation within a prepared surgical opening in subchondral bone of a patient at an articular cartilage site, the surgical opening having a three-dimensional contour other than a circular cylinder, the implant comprising:

a plug body with a stabilizing portion for receipt within the surgical opening;

said stabilizing portion of said plug body presenting a three-dimensional contour other than a circular cylinder and configured for mated receipt within the surgical opening to provide a mechanical interlock against rotation.

49. A method for repairing articular cartilage in a patient, comprising:

implanting a first osteochondral plug graft at an articular cartilage site in the patient, the first osteochondral graft having a first body of bone and a first cartilage layer attached to the first body of bone;

implanting a second osteochondral plug graft adjacent to the first osteochondral plug graft at the articular cartilage site, the second osteochondral graft having a second body of bone and a second cartilage layer attached to the second body of bone; and

wherein first and second bodies of bone, as implanted, are in a nested relationship with one another.

50. The method of claim 49, wherein said nested relationship further provides a mechanical lock against lateral separation of the first and second osteochondral plug grafts.

56. The method of claim 49, wherein said nesting relationship provides a mechanical interlock that provides resistance to rotation of at least one of said first graft and said second graft.

58. The method of claim 49 wherein the patient is human and the osteochondral plug graft is an allograft.

61. The method of claim 49, also comprising administering an osteogenic protein to the articular cartilage site.

62. The method of claim 61, wherein the osteogenic protein comprises a bone morphogenic protein (BMP).

63. The method of claim 62, wherein the BMP comprises recombinant human BMP-2.

51. (canceled)

52. (canceled)

53. (canceled)

54. (canceled)

55. (canceled)

57. (canceled)

59. (canceled)

60. (canceled)

64. (canceled)

65. A method for repairing articular cartilage in a patient, comprising:

implanting a first plug body at an articular cartilage site in the patient;

implanting a second plug body adjacent to the first plug body at the articular cartilage site; and

wherein first and second plug bodies, as implanted, are in a nested relationship with one another.

66. An implant for receipt within an opening in subchondral bone at an articular cartilage site of a patient, the implant comprising:

a plug body configured for receipt within said opening in subchondral bone, wherein said plug body has at least a portion having sidewalls presenting a cross sectional profile selected from

a) a non-circular profile that includes at least one circular arc;

b) a polygonal profile;

c) an ovate profile; and

d) a multi-lobed profile having two to four lobes.

67. The implant of claim 66, wherein the implant is an osteochondral graft including a bone plug having an upper surface, sidewalls depending from said upper surface, and a lower surface, and a layer of cartilage attached to the upper surface of the bone plug, and wherein said sidewalls present said cross sectional profile.

68. The implant of claim 67, wherein said cross sectional profile is a non-circular profile that includes at least one circular arc.

69. The implant of claim 68, wherein said cross sectional profile is defined by multiple intersecting circular arcs.

70. The implant of claim 66, wherein said cross sectional profile is a polygonal profile.

77. The implant of claim 66, wherein said cross sectional profile is multi-lobed having two to four lobes.

78. The implant of claim 77, wherein said lobes each include a circular arc.

71. (canceled)

72. (canceled)

73. (canceled)

74. (canceled)

75. (canceled)

76. (canceled)

79. An implant system for receipt within an opening in subchondral bone at an articular cartilage site in patient, comprising a first plug body and a second plug body, wherein said first and second plug bodies are configured to cooperate with one another to nest, to mechanically lock at least one of the bodies against rotation, and/or to mechanically lock the bodies against lateral separation, when implanted in the opening.

80. The implant system of claim 79, wherein the first and second plug bodies are osteochondral plug grafts.

81-93. -93. (canceled)

94. A method for repairing an articular cartilage site in a patient, comprising:

providing a prepared surgical opening in subchondral bone of a patient at an articular cartilage site; and

inserting a plurality of plug bodies into said surgical opening, said plurality of plug bodies together providing a plug assembly substantially filling said opening.

95. The method of claim 94, wherein said plug assembly has from two to four plug bodies.

96. The method of claim 94, wherein said plug assembly provides an interference fit in said opening.

97. The method of claim 95, wherein said plug bodies are osteochondral grafts.

98. The method of claim 94, wherein said plug grafts each include a body comprised of a synthetic polymer.

99. An implant system configured for stable implantation within a prepared surgical opening in subchondral bone of a patient at an articular cartilage site, comprising a plurality of plug bodies together providing a plug assembly configured to substantially fill the surgical opening.

100. The implant system of claim 99, wherein said plug bodies have graft wall portions configured to mate with one another.

101. The implant system of claim 100, wherein said plug body wall portions are substantially straight walls.

102. The implant system of claim 101, wherein said plug bodies have rectangular cross-sectional profiles.

103. The implant system of claim 99, wherein the plug bodies are osteochondral plug grafts.