WO2003077728A2

WO2003077728A2 - Adjustable suture anchor

Info

Publication number: WO2003077728A2
Application number: PCT/US2003/007558
Authority: WO
Inventors: John H. Morriss; Daniel Jacobs; Robert J. Elson
Original assignee: Coapt Systems, Inc.
Priority date: 2002-03-12
Filing date: 2003-03-12
Publication date: 2003-09-25
Also published as: AU2003220197A8; WO2003077728A3; AU2003220197A1

Abstract

A suture retaining plug (46) comprising two halves (32) and a vertex-retaining hole (42). The plug is designed to hold a suture within the hole. The plug comprises as a proximal section (32) and a distal section (36). The proximal section serves as the head for the plug. The distal section is an anchoring section. The distal section is an anchoring section. The distal section can comprise a plurality of protrusions (44).

Description

ADJUSTABLE SUTURE ANCHOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application

Serial No. 60/365,023 filed March 12, 2002.

FIELD OF THE INVENTION [0002] The present invention relates generally to suturing methods and apparatus.

More particularly, the present invention relates to suturing devices for adjustably anchoring sutures.

BACKGROUND OF THE INVENTION

[0003] Suture anchors are commonly used to retain sutures within a region of tissue and/or bone. Conventional suture anchors are typically made of biocompatible materials and are used to bind openings or tears in the soft tissue of the body. These wounds are approximated and held by sutures which are typically tied together by knotting. This relatively simple task, however, requires much concentration and the use of both hands by the physician or practitioner in ensuring a good tight seal.

[0004] However, tensioning adjustments may need to be made to a suture during or after the suturing procedure to add or remove slack in the suture either due to the movement of tissue and/or bone or to enhance the efficacy of the soft tissue coaption. Moreover, because of patient movement, whether voluntary or involuntary, there is a danger of wounds being pulled apart or widening. This may require completely resuturing an area of tissue and possibly re-anchoring a new suture anchor to accommodate the new sutures. Finally, a physician may prefer to use the suture as a method of anchoring a region of soft tissue to the bone wherein the bone anchor location is at a remote location to the point of soft tissue fixation.

[0005] Some conventional suture anchors are described in the following references, which are incorporated herein by reference in their entirety.

[0006] U.S. Pat. No. 6,309,405 (Bonutti) describes anchors formed from body tissue.

A suture is inserted into a passage within the anchor which is then positioned in a patient's body. The suture extends into the passage within the anchor. However, once the suture is implanted within the anchor and placed within the body, subsequent adjustments to the suture are made difficult because of the suture and anchor placement within the bone. [0007] U.S. Pat. No. 6,270,518 (Pedlick et al.) describes a wedge shaped suture anchor and a method of implantation. The anchor is fabricated by angular cuts and defines bore holes through which sutures may be passed. Both the anchor and the suture are seated within the body and bite into the walls of the bone to provide the anchoring force. However, this device is also difficult to adjust for suture tensioning and still requires two-handed operation.

[0008] U.S. Pat. No. 6,241,749 (Rayhanabad) describes an adjustable tension device for sutures which comprises a body through which sutures may be knotted at the top of the body. The body has a plurality of flexible legs extending outwardly and downwardly to rest on the body of the patient.

[0009] U.S. Pat. No. 6,015,428 (Pagedas) describes an integrally formed suture and suture lock which comprises a self-adjusting suture lock and a thread retaining opening. The suture lock, in part, comprises tongues having a conical section shape which lock onto a suture passed therethrough. The springiness and engagement of each tongue against the suture prevents the suture from being withdrawn. This adjustability, however, allows only for the tensioning of a suture and not complete adjustability.

SUMMARY OF THE INVENTION [0010] A implantable suture anchor is described below which is capable of accommodating various suture sizes and which allows for the repeated adjustment of suture lengths without the need for the tying of knots. One variation of the suture anchor comprises a shaft portion having a first diameter and a head portion having a second diameter which is preferably larger than the first diameter. The shaft preferably defines a chamfered distal end to facilitate positioning and placement within bone and the shaft also preferably defines radially extending tabs along the outer surface of the shaft. Any number of tabs may be defined and are used to provide an enlarged local diameter to aid in preventing the anchor from being pulled out of the bone or rotating within the bone.

[0011] Another variation of the suture anchor may comprise a shaft portion having a first diameter, a post portion having a second diameter, and a head portion having a third diameter. The post portion, around which the suture may be wrapped, may have the smallest cross section relative to the other portions and it may assume, e.g., a circular, oval, or oblong shape. The distal end of the post portion may include one or several additional posts or pegs that may protrude distally for insertion into additional holes bored into the bone. These additional posts or pegs may key the anchor within the bone hole to aid in preventing rotation of the anchor within the hole when implanted. Furthermore, an optional channel may be circumferentially defined along a portion of the the post to further define a region within which the suture may be securely wrapped about.

[0012] The head may have a through hole defined to extend perpendicularly through the anchor relative to a longitudinal axis defined by the head and shaft. Furthermore, the head also defines an aperture which preferably extends at least partially into the head towards the longitudinal axis defined by the anchor. This aperture may be in the form of a notch or other forms that allow for suture positioning and stability within the device. The notch may be located anywhere along the head. The notch may further define an edge which is angled through the thickness of the head to help facilitate retention of a suture. [0013] The suture anchor may be fabricated as a singular, integral device preferably formed from biocompatible materials such as metals, e.g., stainless steels, nickel alloys, titanium alloys, etc., from polymeric materials such as polyglycolide, polylactide, etc., which may optionally be bioabsorbable as well, or from natural materials such as bone. Furthermore, the suture anchor may alternatively be fabricated as two separate halves or as two joined halves assembled as a single piece. Such a separable anchor may be completely separable or it may be partially connected via a connecting bridge. In either case, the separable anchor preferably forms a similar configuration when fully assembled as the integral anchor. When assembled, each half of the separable anchor assembly may be brought together pivotally about the connecting bridge such that each adjoining surface comes into contact with one another. When each half is brought together, the assembly may be held together by a variety of mechanical fastening mechanisms, e.g., locking posts, interfitting tabs, adhesives, etc.

[0014] Prior to use, a suture may be pre-loaded within the through hole either by threading it through or by placing it in the through hole halves, if the separable anchor is used, prior to anchor assembly. This preliminary step eliminates the need for separately threading the suture through a small hole. When a selected region of tissue is to be sutured to a region of bone, a hole may initially be drilled at a desired location for the anchor. Alternatively, the anchor may be placed within an anchoring hole which has been drilled or bored into the anchoring region, e.g., bone, and the suture may be subsequently fed through the through hole.

[0015] When the anchor is positioned within the bored hole, the shaft is preferably press fit or friction fitted into the hole. This requires that the hole have a diameter which is slightly smaller than or the same as the diameter of the shaft or tabs. Although not necessary, the anchor may be positioned within the hole such that through hole is aligned along the direction of the tensile load created by the tissue pulling on the suture. Also, the notch may be positioned to face away from the direction of the tensile load. Moreover, the anchor is also preferably positioned such that the longitudinal axis defined by the anchor is positioned perpendicularly relative to the bone surface.

[0016] In use, after the anchor has been desirably positioned, the free end of the suture, which may be attached to a suturing needle, may be passed through the tissue to be approximated or held and the free end may then be brought back to the anchor. The tension on the suture may be adjusted as necessary by pulling the free end of the suture to adjust accordingly. When the desired length and tension has been achieved, the suture free end may be wrapped about the shaft or post in or between the head and the bone surface. The suture free end may be wrapped about the shaft a number of times ranging anywhere from 45° to more than 360° relative to the longitudinal axis and the through hole and then the free end may be secured within the notch. To readjust the suture, the suture free end may be pulled up and out of the notch, unwrapped from the shaft, and the tension may be readjusted as necessary. Afterwards, the suture free end may be resecured in the manner described above. [0017] Alternatively, the suture may be affixed within the body of the anchor by various fastening methods prior to positioning. Once the suture has been fixed within the anchor, the suturing, tensioning, and retensioning of the tissue may be accomplished in the same manner as described above.

[0018] In yet another alternative, the suture may be attached to the tissue and the free end of the suture may be loaded within the through hole and simply wrapped about the anchor to hold the tissue in place. Again, the free end may simply be unwrapped and adjusted accordingly and then rewrapped as necessary. Other variations on methods of anchoring and the suturing anchors themselves which are obvious variations are intended to be within the scope of this application.

[0019] The present methods and anchor variations obviate the need for tying knots in the sutures or the use of other conventional methods to obtain a secure fit; moreover, suturing is simplified since the physician or practitioner can use a single hand for adjustments and readjustments as necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figs. 1 A to ID show various perspectives on a variation of the adjustable suture anchoring apparatus.

[0021] Figs. 2A to 2D show various perspectives on another variation of the adjustable suture anchoring apparatus which is capable of being split.

[0022] Figs. 3 A to 3D show various perspectives of the disassembled apparatus of

Figs. 2A to 2D.

[0023] Figs. 4A to 4C show a top view of a suturing assembly to illustrate one method of suturing using the device of Figs. 2A to 2D.

[0024] Fig. 4D shows a side view from Fig. 4B of a suturing anchor positioned in bone.

[0025] Figs. 5 A to 5D show various perspectives of another variation of the adjustable suture anchoring apparatus.

[0026] Figs. 6 A to 6D show various perspectives of yet another variation of the adjustable suture anchoring apparatus.

DETAILED DESCRIPTION OF THE INVENTION

[0027] Suture anchors are typically used to anchor select regions of the body to one another. A suture anchor which is implantable within bone is described herein which accommodates various suture sizes and which allows for the repeated adjustment of suture lengths to adjust for tensioning differences without the need for the tying of any knots. Side and top views of one variation of a suture anchor which is desirably adjustable are seen in Figs. 1A and IB. This variation of suture anchor 10 is comprised of head 12 having a thickness, e.g., 1.50 mm (about 0.060 in.), and a first diameter, e.g., 6.00 mm (about 0.240 in.). Shaft 14 preferably extends from one side of head 12 and may optionally define a distal chamfered end 16. The distal end may be chamfered 16 at an angle, α, which may be about 30°, as shown in Fig. 1C to facilitate placement of anchor 10 into the bone. Shaft 14 is shown having a second diameter, e.g., 3.85 mm (about 0.150 in.), which is smaller than the first diameter of head 12; however, shaft 14 may alternatively have a larger diameter or the same diameter of head 12. Between head 12 and shaft 14, a through hole 18 may be defined to extend perpendicularly through anchor 10 relative to longitudinal axis 22 defined by head 12 and shaft 14. Although through hole 18 is shown to extend perpendicularly through anchor 10, it may be defined through a range of angles and is not limited to being perpendicular.

[0028] Another variation of the suture anchor may comprise shaft portion 14 having a first diameter, a post portion having a second diameter, and head portion 12 having a third diameter. The post portion, around which the suture may be wrapped, may have the smallest cross section relative to the other portions 12, 14 and it may assume, e.g., a circular, oval, or oblong shape.

[0029] An aperture is defined as extending at least partially into head 12 towards the longitudinal axis 22 defined by anchor 10. This aperture may be in the form of a notch 20 extending into head 12 but it may also take various other forms. The width and angle of notch 20 may be varied accordingly to suit the size of the suture being used. Fig. IC shows a cross-sectioned view taken from Fig. IB and illustrates the location of through hole 18. As shown, through hole 18 preferably extends entirely through shaft 14 and head 12 with a diameter large enough to accommodate various suture sizes. For example, through hole 18 may have a diameter of 0.50 mm (about 0.020 in.).

[0030] Although notch 20 may be located anywhere along head 12, notch 20 may be aligned with through hole 18, as shown in Figs. 1 A and IC. Additionally, notch 20 preferably defines a vertex pointing to longitudinal axis 22 and may further define an edge which is angled through the thickness of head 12 to facilitate retention of a suture, as described in detail below. This angled edge is defined by the angle, β, which may be about 20° relative to longitudinal axis 22. Fig. ID shows an isometric view of anchor 10 and illustrates the relative sizes and possible positioning of notch 20 in the device. [0031] The suture anchor 10 may be fabricated as a singular, integral device, as seen in Figs. 1 A to ID, preferably from biocompatible materials such as metals, e.g., stainless steels, nickel alloys, titanium alloys, etc., from polymeric materials such as polyglycolide, polylactide, etc., which may optionally be bioabsorbable as well, or from natural materials such as bone. A suture anchoring device may alternatively be fabricated as two separate halves or as two joined halves assembled as a single piece. Figs. 2 A to 2D show another variation on the device which may be formed by two separate halves. [0032] Figs. 2A to 2C show side, top, and another side view, respectively, of anchor variation 30. Fig. 2A shows anchor 30 having a bisected head 32 and shaft 34. Similar to anchor 10 from Figs. 1 A to ID, anchor 30 may have an optional chamfer 36 at a distal end which connects the two halves via a connecting bridge 38. Each half, when assembled, may define through hole 40 which preferably extends through anchor 30 similarly to anchor 10. Moreover, the two halves may also define notch 42 when assembled, as above. Tabs 44 may be located along the surface of shaft 34 and preferably extend radially to locally increase the shaft 44 diameter. Tabs 44 may be integrally formed in shaft 34 or they may be separately attached to shaft 34. In either case, they are preferably utilized to aid in keeping shaft 34 anchored in the bone. Although two tabs 44 are shown in the figures, any number of tabs may be used as practicable. Tabs 44 may also be formed on suture anchor 10 shown in Figs. 1 A to ID. Fig. 2D shows an isometric view of anchor 30 and also shows dividing plane 46 along which anchor 30 may be joined.

[0033] Figs. 3 A to 3 C show side, bottom, and end views, respectively of anchor 30 in its disassembled form. Anchor assembly 30' may be seen as being formed of two halves joined by connecting bridge 38. Each half of through hole walls 40' and notch walls 42' may be seen prior to forming anchor 30 from each half. When assembled, each half of assembly 30' may be brought together pivotally about connecting bridge 38 such that each adjoining surface 46' comes into contact with one another. Fig. 3D shows an isometric view of assembly 30'. When each half is brought together, the assembly 30' may be made to retain its shape initially via locking posts 50. Posts 50 are configured to fit into corresponding receiving holes 52 on the complementary half of assembly 30' via an interference friction fit or other conventional fastening mechanisms, e.g., interfitting tabs, adhesives, etc. Two posts 50 are shown in the figure but any number of posts may be utilized as practicable. [0034] In use, one method of utilizing the suture anchor, e.g., anchor 30, is shown in suture assembly 60 shown in Figs. 4 A to 4D which illustrates top views of a suturing method. When a selected region of tissue is to be sutured to a region of bone, a hole may initially be drilled at a desired location for the anchor 30. Suture 62 may be fed within through hole 40 prior to installing anchor 30 into the anchoring hole 66 bored into the bone. If an integral anchor, such as anchor 10 is used, suture 62 is preferably loaded within the through hole prior to placement of the anchor into the bone. If an anchor assembly such as anchor 30 is used, suture 62 may be loaded within the through hole 40 after anchor 30 has been assembled; alternatively, suture 62 may be placed within through hole halves 40' while anchor 30' is disassembled and anchor 30 may be formed while maintaining the suture 62 within the formed through hole 40. This option eliminates the need to feed the suture 62 within the through hole 40.

[0035] Alternatively, anchor 30 may be placed within anchoring hole 66 and suture

62 may be subsequently fed through the through hole 40. When anchor 30 is positioned within anchoring hole 66, shaft 34 is preferably press fit or friction fit into hole 66. This requires that hole 66 be bored with a diameter which is slightly smaller than or the same as the diameter of shaft 34. Optionally utilized tabs 44 on shaft 34 may be used to aid in creating the press fit, as seen in Fig. 4D. Although not necessary, anchor 30 may be positioned within hole 66 such that through hole 40 is aligned along the direction of the tensile load T on suture 62 and notch 42 is facing away from the direction of tensile load T, as shown in Fig. 4A. Moreover, anchor 30 is also preferably positioned such that the longitudinal axis defined by anchor 30 is perpendicular relative to bone surface 64, as seen in Fig. 4D.

[0036] After anchor 30 has been desirably positioned within the anchoring hole 66, as seen in Fig. 4 A, the free end 62' of the suture, which may be attached to a suturing needle (not shown), may be passed back through the tissue to be approximated or held and the free end 62' may then be brought back to anchor 30. Suture 62 may already be attached to a region of tissue to be sutured. At this point, the tension T on suture 62 may be adjusted as needed by pulling the free end 62' of the suture to adjust accordingly. When the desired length and tension T has been achieved, suture free end 62' may be wrapped about shaft 34 inbetween head 32 and bone surface 64, as shown in Figs. 4B and 4D. Suture free end 62' may be wrapped about shaft 34 any number of times ranging from 45° to more than 360° and then secured within notch 42, as shown in Fig. 4C. If readjustment of tension T is required, suture free end 62' may be pulled up and out of notch 42, unwrapped from shaft 34, and tension T may be readjusted as necessary. Afterwards, suture free end 62' may be resecured in a manner described above.

[0037] Fig. 4C shows each half of head 32 slightly separated at adjoining surface 46 when suture free end 62' has been wedged within notch 42. Forming anchor 30 from two halves adds a redundant securing mechanism in that suture free end 62' may still be secured by pulling it past the notch 42 such that it may be held between adjoining surface 46, even when notch 42 may have dulled during use or if each half of head 32 has separated slightly during insertion. This method and anchor obviates the need for tying knots in the sutures to obtain a secure fit; moreover, suturing is simplified such that the physician or practitioner can use a single hand for adjustments and readjustments as necessary.

[0038] In an alternative method, suture 62 may be fixedly attached within the body of anchor 30 prior to positioning anchor 30 within anchoring hole 66. This may be accomplished via a variety of methods such as adhesives or mechanically fastening the suture to a fixed point within anchor 30 prior to assembling the anchor. Once suture 62 has been fixed within anchor 30, the suturing, tensioning, and retensioning of the tissue may be accomplished in the same manner as described above.

[0039] In yet another alternative, suture 62 may be attached to the tissue to be approximated to provide the tensile loading T. The free end 62' may then be brought within through hole 40 and simply wrapped about anchor 30 to hold the tissue in place. Again, free end 62' may simply be unwrapped and adjusted accordingly and then rewrapped as necessary.

[0040] Figs. 5 A to 5C show side, top, and another side view, respectively, of yet another anchor variation 70. These views show half of the anchor variation 70 for the sake of simplicity and is only intended to be illustrative of this variation. This variation 70 may be formed in a half configuration, as illustrated, and joined together with a complementary half along dividing plane 78. These halves may be optionally formed separately, or they may be joined via a connecting bridge or hinging region, as described above. Alternatively, the variation 70 may be formed as a single integral device with both halves. [0041] Fig. 5A shows anchor 70 having head 72 and shaft 74. Similar to anchor variations above, anchor 70 may have an optional chamfer 76 at a distal end. If anchor 70 were formed in a half configuration, it may optionally define a through hole within which the suture may be secured, as described above. Optional tabs or protrusions 80 may be formed along a portion of shaft 74, as shown, extending radially beyond the surface of shaft 74 to increase the diameter locally. Protrusion 80 may be formed as discrete members or it may be formed circumferentially about shaft 74. Protrusion 80 may be integrally formed with shaft 74 or it may be separately attached to shaft 74. In either case, protrusion 80 may be optionally utilized to aid in keeping anchor 70 secured in the bone. [0042] An optional channel or groove 82 may be defined circumferentially about a portion of shaft 74. Channel 82 may be defined adjacent to head 72, or it may be defined along a distal portion of shaft 74. A suture may be wrapped one or several times about anchor 70 within channel 82. Anchor 70 may thus be positioned within the bone such that channel 82 is just above the surface of the bone. Alternatively, once the suture is desirably wrapped and/or tied within or about channel 82, anchor 70 may be urged into the bone such channel 82 is located at some point below the bone surface. Fig. 5D shows an isometric view of anchor 70 and also shows dividing plane 78 along which anchor 70 may be joined. [0043] Figs. 6A to 6D show yet another variation of the anchor 70' with the addition of posts or pegs which may be formed at or along the distal end of the anchor 70'. As above, these views show half of the anchor variation 70' for the sake of simplicity and is only intended to be illustrative. Pegs or posts 90, 92 may protrude from the distal end of the anchor 70' for placement into additional bone holes bored for the protrusions. These posts 90, 92 may extend from the distal end to aid in preventing rotation of the anchor 70' about its own longitudinal axis once implanted within the bone and placed under a loading condition, e.g., by a suture secured to anchor 70'. Although two posts 90, 92 are shown in the figures, any number of posts may be utilized as practicable. Moreover, posts 90, 92 may include an optional radial protrusion or detent 94, as shown on post 90, to further facilitate secure placement of the post within the bone hole. Only post 90 is shown in this example as having a detent 94; however, both, either, or neither post 90, 92 may include a detent 94. Other variations on methods of anchoring and the suturing anchors themselves which are obvious variations are intended to be within the scope of this application and of the claims. [0044] The applications of the suturing assembly and methods of use discussed above are not limited to the suturing and approximation of soft tissue types but may include any number of further treatment applications. Other treatment sites may include various areas or regions of the body and other types of procedures such as scalp fixation, tendon-to-bone fixation, ligament reconstruction, intra-pelvic suspension procedures, laryngeal suspension, facial suspension, etc. Modification of the above-described assemblies and methods for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the art are intended to be within the scope of the claims.

Claims

CLAIMSWe claim:

1. An implantable device for adjustably anchoring a suture, comprising: a post which is adapted for secure placement within bone; and a proximal portion formed proximally on the post, the proximal portion defining an aperture adapted to adjustably secure a portion of the suture therein.

2. The implantable device of claim 1 wherein the post has a cross sectional shape selected from the group consisting of circles and ovals.

3. The implantable device of claim 1 wherein the post has a first diameter and the proximal portion has a second diameter greater than the first diameter.

4. The implantable device of claim 1 wherein the post has a diameter equal to a diameter of the proximal portion.

5. The implantable device of claim 1 wherein the post defines a chamfered distal end.

6. The implantable device of claim 1 wherein the proximal portion has a cross sectional shape selected from the group consisting of circles and ovals.

7. The implantable device of claim 1 wherein the proximal portion is perpendicularly positioned relative to a longitudinal axis of the post.

8. The implantable device of claim 1 wherein the aperture comprises a notch extending at least partially into the proximal portion.

9. The implantable device of claim 8 wherein the notch defines a vertex which points to a longitudinal axis of the post.

10. The implantable device of claim 1 wherein the post defines a channel circumferentially about the post.

11. The implantable device of claim 10 wherein the channel is defined adjacent to the proximal portion.

12. The implantable device of claim 1 further comprising at least one protrusion extending from the post.

13. The implantable device of claim 12 wherein the at least one protrusion comprises a circumferentially shaped protrusion extending radially from the post.

14. The implantable device of claim 1 wherein the device defines a through hole extending perpendicularly relative to a longitudinal axis defined by the post.

15. The implantable device of claim 1 wherein the device is comprised of at least two complementary halves, each half adapted to be fitted to one another.

16. The implantable device of claim 1 further comprising at least one protrusion extending from a distal end of the post.

17. The implantable device of claim 16 further comprising a plurality of additional protrusions extending from the distal end.

18. The implantable device of claim 16 wherein the protrusion further comprises a detent.

19. A method for adjustably anchoring a suture to bone, comprising: anchoring an implantable device within the bone relative to a region to be sutured; wrapping a portion of the suture about the implantable device adjacent to a surface of the bone; and wedging a length of the suture within an aperture defined along the implantable device such that the suture resists a tensile force.

20. The method of claim 19 wherein anchoring the implantable device comprises anchoring a post within the bone.

21. The method of claim 20 further comprising anchoring the post within the bone such that the aperture extends in a direction away from the suture.

22. The method of claim 19 wherein wrapping the portion of the suture comprises wrapping the suture at least once about a post of the implantable device.

23. The method of claim 22 further comprising wrapping the suture at least once within a channel defined circumferentially about the post.

24. The method of claim 22 further comprising threading the suture within a through hole defined within the implantable device prior to wedging the length of the suture.

25. The method of claim 19 wherein wedging the length of the suture comprises wedging the length within a notch extending at least partially into a proximal portion of the implantable device.

26. The method of claim 19 further comprising readjusting the portion of the suture about the implantable device.