KNOTLESS SUTURE ANCHOR FOR SOFT TISSUE REPAIR AND METHOD OF USE

• US 20100063542A1
• Filed: 09/08/2008
• Published: 03/11/2010
• Est. Priority Date: 09/08/2008
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Cheng, Christopher T., Feezor, Christopher, van der Burg, Erik, Cohen, Nathaniel
• Granted Patent: US 8,777,990 B2
• Time in Patent Office: Days
• US Class Current: 606/232
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 2017/0404 Buttons
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening lateral eyelet for attaching suture to needle A61B2017/06019
• CPC Class Codes: A61B 2017/0438 slotted, i.e. having a longitudinal slot for enhancing their elasticity
• CPC Class Codes: A61B 2017/045 snug fit within the anchor
• CPC Class Codes: A61B 2017/0451 Cams or wedges holding the suture by friction
• CPC Class Codes: A61B 2017/0453 threaded elements, e.g. set screws
• CPC Class Codes: A61B 2017/0464 for soft tissue
• CPC Class Codes: A61B 2050/3015 transparent
• CPC Class Codes: Y10T 24/2164 Midline

Abstract

A knotless suture anchor provides a method for securing soft tissue to a rigid structure such as bone. The anchor has an inner member that receives suture thread and rotates within an outer tubular member. As the inner member rotates, the suture thread is wrapped onto the inner member thereby increasing contact with the outer tubular member which applies pressure to the wrapped suture thread to retain it in position on the inner member while simultaneously and adjustably tensioning the suture thread. A ratchet prevents undesirable counter-rotation, although the ratchet can be released to permit loosening of the suture thread. Also described is a suture bridge and suture platform for providing further stabilization of a tendon. A method for repairing rotator cuff tears is also described.

Claims

1. A knotless suture anchor for implanting in bone, comprising:

an outer tubular member having a distal end, a proximal end, and an outer wall, the outer wall having an outer dimension selected so that the outer tubular member will fit and be retained within the bone, the outer tubular member having an inner wall;

an inner member being rotatably disposed within the outer tubular member, the inner member having an outer diameter; and

the inner member and the outer tubular member each having an aperture for receiving a suture thread;

wherein the outer diameter of the inner member is selected to be large enough such that as the inner member having a suture thread received by its aperture is rotated, the suture thread is drawn through the aperture of the outer tubular member and wraps onto the inner member thereby increasing the effective diameter of the inner member with the wrapped suture thread coming into contact with the inner wall of the outer tubular member, such contact exerting an inward force on the wrapped suture thread to maintain it in position on the inner member.

2. The knotless suture anchor of claim 1, wherein the outer dimension of the outer tubular member is selected to that it has a friction fit with the bone.

3. The knotless suture anchor of claim 1, wherein the outer surface of the outer tubular member includes engagement features formed thereon that engage the bone in which the anchor is positioned.

4. The knotless suture anchor of claim 1, further comprising a ratcheting mechanism mounted to the inner member and outer tubular member configured to permit rotation of the inner member in a first direction in relation to the outer tubular member while preventing rotation of the inner member in a second direction, the ratcheting mechanism comprising a pawl and a plurality of teeth.

5. The knotless suture anchor of claim 4, wherein the inner member comprises a pawl of the ratcheting mechanism and the outer tubular member comprises teeth of the ratcheting mechanism, the inner member and outer tubular member being disposed in relation to each other so that the pawl engages the teeth to permit rotation of the inner member in the first direction while preventing rotation in the second direction.

6. The knotless suture anchor of claim 5, wherein:

the outer tubular member comprises a plurality of ratchet apertures that function as ratchet teeth; and

the inner member has a plurality of flexible pawls biased outwardly and at an angle to engage the ratchet apertures of the outer tubular member permitting relative rotation of the inner member within the outer tubular member in a first direction while preventing relative rotation in the second direction.

7. The knotless suture anchor of claim 6, wherein the flexible pawls comprise an angle at their top surfaces permitting axial movement of the inner member in relation to the outer tubular member such that the flexible pawls may be withdrawn from the ratchet apertures of the outer tubular member so that rotation in the second direction is permitted.

8. The knotless suture anchor of claim 6, further comprising a spring disposed in contact with the inner member and the outer tubular member configured to bias the flexible pawls into position in the ratchet apertures of the outer tubular member.

9. The knotless suture anchor of claim 8, wherein the spring is disposed such that the inner member may be moved an axially controlled amount such that the ratchet mechanism is temporarily disengaged to permit counter-rotation of the inner member to loosen the suture.

10. The knotless suture anchor of claim 4, wherein the inner member comprises teeth of the ratcheting mechanism and the outer tubular member comprises a pawl of the ratcheting mechanism, the inner member and outer tubular member being disposed in relation to each other so that the pawl engages the teeth to permit rotation of the inner member in the first direction while preventing rotation in the second direction.

11. The knotless suture anchor of claim 1, further comprising a spring disposed in contact with the inner member to bias the inner member into a predetermined position in relation to the outer tubular member at which the ratchet mechanism is engaged to prevent rotation in the second direction.

12. The knotless suture anchor of claim 11, wherein the spring is disposed such that the inner member may be moved by a predetermined amount against the spring such that the ratchet mechanism is temporarily disengaged to permit rotation of the inner member in the second direction.

13. The knotless suture anchor of claim 1, further comprising a tension indicator located at the outer tubular member in contact with the suture, wherein the tension indicator is adapted to visually indicate an amount of tension on the suture.

14. The knotless suture anchor of claim 1, wherein the outer tubular member comprises first and second suture thread guides disposed at the outer wall of the outer tubular member between the distal and proximal ends, the first and second suture thread guides being angularly separated from each other about the outer wall of the outer tubular member and each having a hole with a size that is large enough to receive a suture thread, the guide holes having a longitudinal axis that is substantially parallel to a longitudinal axis of the inner member, wherein the thread guides do not extend beyond either the distal or proximal ends of the outer tubular member.

15. The knotless suture anchor of claim 14, wherein the first and second suture thread guides are disposed one hundred and eighty degrees (180°

) apart on the outer wall of the outer tubular member.

16. The knotless suture anchor of claim 14, further comprising first and second suture thread guide channels, each of which is disposed in alignment with a respective suture thread guide between the suture thread guide and an aperture in the outer surface of the outer tubular member, each guide channel comprising a relieved portion of the outer surface of the outer tubular member having a depth selected so as to receive a suture thread, whereby a suture thread disposed in the knotless suture anchor is guided by the thread guides and guide channels to positions that are away from contact with surrounding bone.

17. The knotless suture anchor of claim 14, further comprising a tension indicator located at a suture thread guide in contact with the suture, wherein the tension indicator is adapted to visually indicate an amount of tension on the suture.

18. The knotless suture anchor of claim 1, wherein the apertures of the inner member and the outer tubular member for receiving a suture thread are formed with a diametrical orientation in relation to the inner member and outer tubular member.

19. The knotless suture anchor of claim 1, wherein:

the outer wall of the outer tubular member comprises a retaining portion that is deformable outwardly into contact with the bone to retain the anchor in place in the bone;

wherein as the suture thread is wrapped onto the inner member, the suture thread comes into contact with the retaining portion which thereby applies pressure to the wrapped suture thread to hold it in place on the inner member and the retaining portion also deforms outwardly into engagement with the bone to provide further anchor force of the suture anchor in the bone.

20. The knotless suture anchor of claim 19, wherein the retaining portion of the outer tubular member comprises a buckling element.

21. The knotless suture anchor of claim 19, wherein the retaining portion of the outer tubular member comprises a cantilevered element.

22. The knotless suture anchor of claim 21, wherein the cantilevered element forms a barb extending radially outwardly and toward a proximal end of the outer tubular member.

23. The knotless suture anchor of claim 22, wherein as the suture thread wraps onto the inner member, it comes into contact with the cantilevered element thereby forcing the cantilevered element outwardly into locking engagement with bone.

24. A knotless suture anchor, comprising:

a rotatable shaft having a diametrical aperture for receiving an end of a suture thread;

a shell disposed about the rotatable shaft, the shell having a diametrical aperture through which an end of a suture thread may be passed into engagement with the rotatable shaft;

a ratchet mechanism disposed in contact with the rotatable shaft and shell and configured to permit the rotatable shaft to rotate in a first direction in relation to the shell but prevent the shaft from rotating in a second direction;

wherein the outer diameter of the shaft and the inner diameter of the shell are selected such that as the shaft is rotated, the suture thread is drawn through the aperture of the shell and wraps onto the shaft thereby increasing the diameter on the shaft as the shaft is rotated, the wrapped suture thread coming into contact with the shell which applies force to the wrapped suture thread to retain it in position on the shaft.

25. The knotless suture anchor of claim 24, wherein the shaft comprises a device acting as a ratchet pawl and the shell comprises features acting as teeth with which the pawl engages to form the ratchet mechanism.

26. The knotless suture anchor of claim 24, further comprising a spring disposed in contact with the shaft and the shell to bias the two together into a predetermined position at which the ratchet mechanism will prevent rotation in the second direction.

27. The knotless suture anchor of claim 26, wherein the spring is disposed such that the shaft may be moved by a predetermined amount against the spring such that the ratchet mechanism is temporarily disengaged to permit rotation of the shaft in the second direction to loosen the suture thread.

28. The knotless suture anchor of claim 24, further comprising a tension indicator located at the shell in contact with the suture thread, wherein the tension indicator is adapted to visually indicate an amount of tension on the suture thread.

29. The knotless suture anchor of claim 24, wherein the outer tubular member comprises first and second suture thread guides disposed at the outer wall of the outer tubular member between the distal and proximal ends, the first and second suture thread guides being angularly separated from each other about the outer wall of the outer tubular member and each having a hole with a size that is large enough to receive a suture thread, the guide holes having a longitudinal axis that is substantially parallel to a longitudinal axis of the inner member, wherein the thread guides do not extend beyond either the distal or proximal ends of the outer tubular member.

30. The knotless suture anchor of claim 29, wherein the first and second suture thread guides are disposed one hundred and eighty degrees (180°

) apart on the outer wall of the outer tubular member.

31. The knotless suture anchor of claim 29, further comprising a tension indicator located at a suture thread guide in contact with the suture, wherein the tension indicator is adapted to visually indicate an amount of tension on the suture.

32. The knotless suture anchor of claim 29, further comprising first and second suture thread guide channels, each of which is disposed in alignment with a respective suture thread guide between the suture thread guide and an aperture in the outer surface of the outer tubular member, each guide channel comprising a relieved portion of the outer surface of the outer tubular member having a depth selected so as to receive a suture thread, whereby a suture thread disposed in the knotless suture anchor is guided by the thread guides and guide channels to positions that are away from contact with surrounding bone.

33. A method for holding soft tissue in apposition with a bone using a suture, comprising

implanting a rotatable shaft in the bone;

engaging the soft tissue with an engaging portion of a suture thread;

engaging an end of the suture thread with the rotatable shaft implanted in the bone;

rotating the shaft in a first direction to wrap the engaged suture thread onto the shaft thereby increasing tension on the suture and on the soft tissue; and

preventing the rotatable member from counter-rotation with a pawl and a plurality of teeth of a ratchet mechanism.

34. The method of claim 33, further comprising applying force against the wrapped suture thread to prevent slippage of the wrapped suture thread on the rotatable shaft.

35. The method of claim 33, further comprising disengaging the ratcheting mechanism temporarily to permit rotation of the shaft in the second direction to loosen the suture.

36. The method of claim 33, further comprising:

guiding the suture thread that engages the rotatable shaft away from the bone about the hole so that ability of the suture thread to come into contact with the bone and cut the bone is restricted.

37. The method of claim 33, further comprising the step of indicating the amount of tension on the suture.

38. The method of claim 37, wherein the step of indication comprises the step of visually indicating the amount of tension on the suture by deformation of a device in contact with the suture near the rotatable shaft.