Self Fixing Assembled Bone-Tendon-Bone Graft

• US 20060271192A1
• Filed: 06/30/2006
• Published: 11/30/2006
• Est. Priority Date: 03/04/2005
• Status: Active Grant

• Current Assignee: RTI Surgical Incorporated
• Original Assignee: RTI Biologics, Inc. (Surgalign Holdings, Inc.)
• Inventors: Bianchi, John R., Sanders, Ben R., Carr, Angela, Kutsavage, Joe, Urbaniak, Daniel J., Lewis, Wesley I., Olsen, Raymond E.
• Granted Patent: US 7,727,278 B2
• Time in Patent Office: Days
• US Class Current: 623/13.140
• CPC Class Codes: A61F 2/0805 Implements for inserting tendons or ligaments
• CPC Class Codes: A61F 2/0811 Fixation devices for tendons or ligaments
• CPC Class Codes: A61F 2002/0829 without deformation of anchor parts, e.g. fixation screws on bone surface, extending barbs, cams, butterflies, spring-loaded pins
• CPC Class Codes: A61F 2002/0841 Longitudinal channel for insertion tool running through the whole tendon anchor, e.g. for accommodating bone drill, guidewire
• CPC Class Codes: A61F 2002/0864 Fixation of tendon or ligament between anchor elements, e.g. by additional screws in the anchor, anchor crimped around tendon
• CPC Class Codes: A61F 2002/0882 Anchor in or on top of a bone tunnel, i.e. a hole running through the entire bone

Abstract

The present invention has multiple aspects relating to assembled self fixing bone-tendon-bone (BTB) grafts and BTB implants. A preferred application in which self fixing assembled bone-tendon-bone (BTB) grafts and implants of the present technology can be used is for ACL repairs in a human patient. In one embodiment, a self fixing BTB graft is characterized by the presence of threads along at least a portion of the exterior surface of one or both bone blocks. In another embodiment, a self fixing assembled bone-tendon-bone implant comprises a removable tendon tensioner which imparts a predetermined tension on the tendon of the BTB graft. In this embodiment, the tensioner can be narrower than the diameter of the bone blocks or can be threaded such that the threads are continuous with the threads of at least one of the bone blocks. The threads facilitate the simultaneous implantation of the leading and trailing bone blocks of the BTB graft in tapped (threaded) holes in the tibia and the femur of a recipient patient. The tensioner maintains the tension on the tendon and the spacing between the bone blocks until the leading bone block is fixed (threaded) in the tapped hole in the femur and the trailing bone block is fixed (threaded) into the tapped tibial bone tunnel. Once the bone blocks are substantially in their fixed positions, the tensioner is removed arthroscopically in the joint space between the tibia and the femur.

Claims

1. A self fixing bone-tendon-bone (BTB) graft, said BTB graft comprising a length of tendon or ligament (collectively “

tendon”

) having two opposing ends, a first opposing end and a second opposing end, wherein a first bone block is attached to said first opposing end of said tendon and a second bone block is attached to said second opposing end of said tendon, and wherein at least one of said first bone block or said second bone block has an exterior surface having threads along at least a portion thereof.

2. The self fixing BTB graft of claim 1, wherein each of said first bone block and said second bone block has an exterior surface having threads along at least a portion thereof, and wherein the threads of said first bone block and said second bone block run in the same direction so that each bone block is implantable in a respective hole in opposing bones of a joint on a patient when the BTB is rotated as a whole in the threaded direction.

3. The self fixing BTB graft of claim 2, wherein the threads on the first bone block have a smaller outer diameter than the threads on the second bone block.

4. The self fixing BTB graft of claim 2, wherein the threads on the first bone block have a diameter which varies along the length of the first bone block.

5. The self fixing BTB graft of claim 1, wherein the first bone block has an exterior surface having threads along at least a portion thereof, and the second bone block has an exterior surface that is substantially cylindrical, stepped, or tapered.

6. The self fixing BTB graft of claim 1 further comprising a tensioner spanning the length of the tendon to exert a predetermined tension on the spanned tendon.

7. The self fixing BTB of claim 6, wherein the tensioner is configured to exert a predetermined tension on the spanned tendon during implantation.

8. The self fixing BTB graft of claim 6, wherein said tensioner is integrated with an inserter.

9. The self fixing BTB graft of claim 8, wherein said inserter is not integrated with said tensioner.

10. The self fixing BTB graft of claim 6, wherein said tensioner is configured to bend, flex, or break away after implantation.

11. The self fixing BTB graft of claim 6, wherein said tensioner comprises a pair of spacers positioned on opposing sides of said tendon.

12. The self fixing BTB graft of claim 6, wherein said tensioner comprises a single spacer having a slot along its length for encasing said tendon.

13. The self fixing BTB graft of claim 6, wherein said first bone block, said second bone block and said tensioner each comprise at least one hole, slot, or groove in alignment for mounting on an insertion tool.

14. The self fixing BTB graft of claim 13, wherein said first bone block, said second bone block and said tensioner each comprise from 2 to 5 holes, slots, or grooves in alignment.

15. The self fixing BTB graft of claim 13, wherein said at least one hole, slot, or groove in alignment comprises a circular cross sectional profile.

16. The self fixing BTB graft of claim 13, wherein said at least one hole, slot, or groove in alignment comprises a non-circular cross sectional profile.

17. The self fixing BTB of graft claim 6, wherein the outside surface of said tensioner is threaded with threads running in the same direction as the threads on said first bone block or on said second bone block.

18. The self fixing BTB graft of claim 17, wherein the threads on the surface of said tensioner are contiguous with the threads on said first bone block or on said second bone block.

19. The self fixing BTB graft of claim 1, wherein said first bone block is an assembled bone block sandwiching the first opposing end of said tendon.

20. The self fixing BTB graft of claim 6, wherein said first bone block is an assembled bone block sandwiching the first opposing end of said tendon.

21. The self fixing BTB graft of claim 1 wherein said first bone block and said second bone block comprise the same or different materials and said materials are selected from the group consisting of cortical bone, cortico-cancellous bone, cancellous bone, calcium phosphate ceramic, hydroxy apatite, synthetic bone, and combinations thereof.

22. The self fixing BTB graft of claim 20, wherein said first bone block and said second bone block comprise cortical bone.

23. The self fixing BTB graft of claim 22, wherein said first bone block comprises a first bone segment comprising cortical bone and a second bone segment comprising cortical bone that sandwich the first end of said tendon;

and said second bone block comprises a third bone segment comprising cortical bone and a fourth bone segment comprising cortical bone that sandwich the second end of said tendon.

24. The self fixing BTB graft of claim 23, wherein said first bone segment comprising cortical bone and said second bone segment comprising cortical bone each have a tendon engaging surface that is textured for gripping the end of said tendon.

25. The self fixing BTB graft of claim 24, wherein the tendon engaging surface of said first bone segment comprising cortical bone comprises compression surfaces and one to ten cavities.

26. The self fixing BTB graft of claim 25, wherein said one to ten cavities comprise one to ten channels.

27. The self fixing BTB graft of claim 26, wherein at least one of said channels comprise a cross-sectional profile selected from the group consisting of rectangular, square, semi-circular, semi-ovular, triangular, trapezoidal, sinusoidal, curvilinear, dovetail, omega-shaped and a combination thereof.

28. The self fixing BTB graft of claim 27, wherein at least one of said channels has an omega-shaped cross-sectional profile.

29. The self fixing BTB graft of claim 23, wherein said tendon engaging surface of said second bone segment comprising cortical bone comprises rows of ridges that angle opposite the direction of pull of said tendon.

30. The self fixing BTB graft of claim 1, wherein said implant is perfused or coated with an osteoinductive substance.

31. A self fixing bone-tendon-bone (BTB) graft for implantation through a tibial tunnel, said BTB graft comprising a length of tendon or ligament (collectively “

tendon”

) having two opposing ends, a first opposing end and a second opposing end, said first opposing end having a leading bone block attached thereto, said second opposing end having a trailing bone block attached thereto, said leading bone block and said trailing bone block each having an exterior surface that is threaded so that the threads run in the same direction, whereby the leading bone block and the trailing bone block are suited for simultaneous threading into tapped holes in a patient'"'"'s femur and tibia, respectively.

32. The self fixing BTB graft of claim 31, wherein the threaded surface is aligned between the leading bone block and the trailing bone block.

33. The self fixing BTB graft of claim 32, wherein the leading bone block has a smaller diameter than the trailing bone block.

34. The self fixing BTB graft of claim 32, wherein said leading bone block is an assembled bone block.

35. The self fixing BTB graft of claim 34, wherein said length of tendon is a bundle of one to ten tendons having a first end and a second end.

36. The self fixing BTB graft of claim 32, wherein said trailing bone block is an assembled bone block.

37. The self fixing BTB graft of claim 32, wherein said leading bone block, said length of tendon, and said trailing bone block are allograft, xenograft or a combination thereof.

38. The self fixing BTB graft of claim 37, wherein said leading bone block, said length of tendon, and said trailing bone block are allograft.

39. The self fixing BTB graft of claim 37, wherein said leading bone block, said length of tendon, and said trailing bone block are xenograft.

40. The self fixing BTB graft of claim 37, wherein said leading bone block, said length of tendon, and said trailing bone block are a combination of allograft and xenograft.

41. The self fixing BTB graft of claim 32 further comprising a tensioner positioned between said leading bone block and said trailing bone block.

42. An assembled self fixing bone-tendon-bone (BTB) graft, the BTB graft comprising a length of tendon or ligament (collectively “

tendon”

) having two opposing ends, a first opposing end and a second opposing end, the first opposing end having a leading bone block assembly attached thereto, the second opposing end having a trailing bone block assembly attached thereto, the leading bone block assembly and the trailing bone block assembly each comprising a substantially cylindrical cross-section and an exterior surface that is threaded so that the threads run in the same direction, whereby the leading bone block assembly and the trailing bone block assembly are suited for simultaneous threading into tapped holes in a patient'"'"'s femur and tibia, respectively;

the leading bone block assembly comprises a first bone segment and a second bone segment sandwiching the first opposing end of said tendon therebetween, the first bone segment and the second bone segment each having a tendon engaging surface that is textured to grip the first opposing end of the tendon therebetween, and an exterior surface that is threaded such that in joined combination the first bone segment and the second bone segment form the threaded leading bone block assembly.

43. The assembled self fixing BTB graft of claim 42, wherein one of said tendon engaging surfaces has an undercut channel for gripping the first opposing end of said tendon.

44. The assembled self fixing BTB graft of claim 43, wherein said undercut channel has an omega-shaped cross-section.

45. The assembled self fixing BTB graft of claim 42, wherein said leading bone block assembly and said trailing bone block assembly each have 2 to 5 holes therethrough, and weherein said 2-5 holes in the leading bone bloack assembly are aligned with said 2-5 holes in the trailing bone block assembly for accommodating prongs of an insertion device.

46. The assembled self fixing BTB graft of claim 42 further comprising a tendon tensioner or spacer positioned between said leading bone block assembly and said trailing bone block assembly.

47. The assembled self fixing bone-tendon-bone (BTB) graft of claim 46, wherein the tensioner is also configured to maintain tension in the tendon during processing of the graft.

48. The assembled self fixing BTB graft of claim 42, wherein said graft is cleaned or perfused by treatment with a pressure cycling process.

49. The assembled self fixing BTB graft of claim 42 further comprising an insertion tool adapted to rotate each of said tensioner, said leading bone block, and said trailing bone block together in the same direction.

50. An assembled self fixing bone-tendon-bone (BTB) graft for implantation through a tibial tunnel, the BTB graft comprising a length of tendon or ligament (collectively “

tendon”

) having two opposing ends, a first opposing end and a second opposing end, the first opposing end having a leading bone block assembly attached thereto, the second opposing end having a trailing bone block assembly attached thereto, the leading bone block assembly and the trailing bone block assembly each comprising a substantially cylindrical cross-section, and a tensioner disposed between the leading bone block assembly and the trailing bone block assembly;

the tensioner configured to maintain tension in the tendon between the two bone block assemblies during implantation.