Method and apparatus for forming a self-locking adjustable suture loop

[0001] The present disclosure relates to method of implanting a prosthetic and, more particularly, to a method of implanting an ACL within a femoral tunnel.

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] It is commonplace in arthroscopic procedures to employ sutures and anchors to secure soft tissues to bone. Despite their widespread use, several improvements in the use of sutures and suture anchors can be made. For example, the procedure of tying knots can be very time consuming, thereby increasing the cost of the procedure and limiting the capacity of the surgeon. Furthermore, the strength of the repair may be limited by the strength of the knot. This latter drawback may be of particular significance if the knot is tied improperly as the strength of the knot in such situations can be significantly lower than the tensile strength of the suture material.

[0004] To overcome this problem, sutures having a single preformed loop have been provided. FIG. 1 represents a prior art suture construction. As shown, one end of the suture is passed through a passage defined in the suture itself. The application of tension to the ends of the suture pulls a portion of the suture through the passage, causing a loop formed in the suture to close. Unfortunately, relaxation of the system can allow a portion of the suture to translate back through the passage, thus relieving the desired tension.

[0005] It is an object of the present teachings to provide an alternative device for anchoring sutures to bone and soft tissue. The device, which is relatively simple in design and structure, is highly effective for its intended purpose.

[0006] To overcome the aforementioned deficiencies, a method for configuring a braided tubular suture and a suture configuration are disclosed. The method includes passing a first end of the suture through a first aperture into a passage defined by the suture and out a second aperture defined by the suture so as to place the first end outside of the passage. A second end of the suture is passed through the second aperture into the passage and out the first aperture so as to place the second end outside of the passage.

[0007] A method of surgically implanting a suture construction in a femoral tunnel is disclosed. A suture construction is formed by passing the suture through a bore defined by a locking member. A first end of the suture is passed through a first aperture within the suture into a passage defined by the suture and out a second aperture defined by the suture so as to place the first end outside of the passage and define a first loop. A second end of the suture is then passed through the second aperture into the passage and out the first aperture so as to place the second end outside of the passage, and define a second loop. The first and second ends and the first and second loops are then passed through the femoral tunnel. Soft tissue is then passed through the first and second loops. Tension is applied onto the first and second ends to constrict the first and second loops about the soft tissue.

[0008] In another embodiment, a method of surgically implanting a suture is disclosed. The suture is passed through a bore defined by a first fastener. A suture construction is formed by passing the suture through a bore defined by a locking member. A first end of the suture is passed through a first aperture within the suture into a passage defined by the suture and out a second aperture defined by the suture so as to place the first end outside of the passage and define a first loop. A second end of the suture is then passed through the second aperture into the passage and out the first aperture so as to place the second end outside of the passage, and define a second loop. A second fastener is coupled to at least one of the first and second loops. After the fastener is coupled to the patient, tension is applied onto the first and second ends to constrict at least one of the first and second loops.

[0009] In another embodiment a method of surgically implanting a soft tissue replacement for attaching two bone members is disclosed. A first and second tunnels are formed in first and second bones. A locking member having a first profile which allows insertion of the locking member through the tunnel and a second profile which allows engagement with the positive locking surface upon rotation of the locking member is provided. The suture construction described above is coupled to the locking member. The first and second ends and the first and second loops of the construction and the locking member are threaded through the first and second tunnels. Soft tissue is threaded through the first and second loops so as to engage bearing surfaces on the first and second loops. The locking member is then engaged.

[0010] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0021] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0022] FIG. 2A represents a suture construction 20 according to the present teachings. Shown is a suture 22 having a first end 24 and a second end 26. The suture 22 is formed of a braided body 28 that defines a longitudinally formed hollow passage 30 therein. First and second apertures 32 and 34 are defined in the braided body 28 at first and second locations of the longitudinally formed passage 30.

[0023] Briefly referring to FIG. 3, a first end 24 of the suture 22 is passed through the first aperture 32 and through longitudinal passage 30 formed by a passage portion and out the second aperture 34. The second end 26 is passed through the second aperture 34, through the passage 30 and out the first aperture 32. This forms two loops 46 and 46′. As seen in FIG. 2B, the relationship of the first and second apertures 32 and 34 with respect to the first and second ends 24 and 26 can be modified so as to allow a bow-tie suture construction 36. As described below, the longitudinal and parallel placement of first and second suture portions 38 and 40 of the suture 22 within the longitudinal passage 30 resists the reverse relative movement of the first and second portions 38 and 40 of the suture once it is tightened.

[0024] The first and second apertures are formed during the braiding process as loose portions between pairs of fibers defining the suture. As further described below, the first and second ends 24 and 26 can be passed through the longitudinal passage 30 multiple times. It is envisioned that either a single or multiple apertures can be formed at the ends of the longitudinally formed passage.

[0025] As best seen in FIGS. 4A and 4B, a portion of the braided body 28 of the suture defining the longitudinal passage 30 can be braided so as to have a diameter larger than the diameter of the first and second ends 24 and 26. Additionally shown are first through fourth apertures 32, 34, 42, and 44. These apertures can be formed in the braiding process or can be formed during the construction process. In this regard, the apertures 32, 34, 42, and 44 are defined between adjacent fibers in the braided body 28. As shown in FIG. 4B, and described below, it is envisioned the sutures can be passed through other biomedically compatible structures.

[0026] FIGS. 5-7 represent alternate constructions wherein a plurality of loops 46a-d are formed by passing the first and second ends 24 and 26 through the longitudinal passage 30 multiple times. The first and second ends 24 and 26 can be passed through multiple or single apertures defined at the ends of the longitudinal passage 30. The tensioning of the ends 24 and 26 cause relative translation of the sides of the suture with respect to each other.

[0027] Upon applying tension to the first and second ends 24 and 26 of the suture 22, the size of the loops 46a-d is reduced to a desired size or load. At this point, additional tension causes the body of the suture defining the longitudinal passage 30 to constrict about the parallel portions of the suture within the longitudinal passage 30. This constriction reduces the diameter of the longitudinal passage 30, thus forming a mechanical interface between the exterior surfaces of the first and second parallel portions as well as the interior surface of the longitudinal passage 30.

[0028] As seen in FIGS. 8-11, the suture construction can be coupled to various biocompatible hardware. In this regard, the suture construction 20 can be coupled to an aperture 52 of the bone engaging fastener 54. Additionally, it is envisioned that soft tissue or bone engaging members 56 can be fastened to one or two loops 46. After fixing the bone engaging fastener 54, the members 56 can be used to repair, for instance, a meniscal tear. The first and second ends 24, 26 are then pulled, setting the tension on the loops 46, thus pulling the meniscus into place. Additionally, upon application of tension, the longitudinal passage 30 is constricted, thus preventing the relaxation of the tension caused by relative movement of the first and second parallel portions 38, 40, within the longitudinal passage 30.

[0029] As seen in FIGS. 9-11B, the loops 46 can be used to fasten the suture construction 20 to multiple types of prosthetic devices. As described further below, the suture 22 can further be used to repair and couple soft tissues in an anatomically desired position. Further, retraction of the first and second ends allows a physician to adjust the tension on the loops between the prosthetic devices.

[0030] FIG. 11b represents the coupling of the suture construction according to FIG. 2B with a bone fastening member. Coupled to a pair of loops 46 and 46′ are tissue fastening members 56. The application of tension to either the first or second end 24 or 26 will tighten the loops 46 or 46′ separately.

[0031] FIGS. 12A-12E represent potential uses of the suture constructions 20 in FIGS. 2A-7 in an ACL repair. As can be seen in FIG. 12A, the longitudinal passage portion 30 of suture construction 20 can be first coupled to a fixation member 60. The member 60 can have a first profile which allows insertion of the member 60 through the tunnel and a second profile which allows engagement with a positive locking surface upon rotation. The longitudinal passage portion 30 of the suture construction 20, member 60, loops 46 and ends 24, 26 can then be passed through a femoral and tibial tunnel 62. The fixation member 60 is positioned or coupled to the femur. At this point, a natural or artificial ACL 64 can be passed through a loop or loops 46 formed in the suture construction 20. Tensioning of the first and second ends 24 and 26 applies tension to the loops 46, thus pulling the ACL 64 into the tunnel. In this regard, the first and second ends are pulled through the femoral and tibial tunnel, thus constricting the loops 46 about the ACL 64 (see FIG. 12B).

[0032] As shown, the suture construction 20 allows for the application of force along an axis 61 defining the femoral tunnel. Specifically, the orientation of the suture construction 20 and, more specifically, the orientation of the longitudinal passage portion 30, the loops 46, and ends 24, 26 allow for tension to be applied to the construction 20 without applying non-seating forces to the fixation member 60. As an example, should the loops 24, 26 be positioned at the member 60, application of forces to the ends 24, 26 may reduce the seating force applied by the member 60 onto the bone.

[0033] As best seen in FIG. 12C, the body portion 28 and parallel portions 38, 40 of the suture construction 20 remain disposed within to the fixation member 60. Further tension of the first ends draws the ACL 64 up through the tibial component into the femoral component. In this way, suture ends can be used to apply appropriate tension onto the ACL 64 component. The ACL 64 would be fixed to the tibial component using a plug or screw as is known.

[0034] After feeding the ACL 64 through the loops 46, tensioning of the ends allows engagement of the ACL with bearing surfaces defined on the loops. The tensioning pulls the ACL 64 through a femoral and tibial tunnel. The ACL 64 could be further coupled to the femur using a transverse pin or plug. As shown in FIG. 12E, once the ACL is fastened to the tibia, further tensioning can be applied to the first and second ends 24, 26 placing a desired predetermined load on the ACL. This tension can be measured using a force gauge. This load is maintained by the suture configuration. It is equally envisioned that the fixation member 60 can be placed on the tibial component 66 and the ACL pulled into the tunnel through the femur. Further, it is envisioned that bone cement or biological materials may be inserted into the tunnel 62.

[0035] FIGS. 13A-13D represent a close-up of a portion of the suture 20. As can be seen, the portion of the suture defining the longitudinal passage 30 has a diameter d₁ which is larger than the diameter d₂ of the ends 24 and 26. The first aperture 32 is formed between a pair of fiber members. As can be seen, the apertures 32, 34 can be formed between two adjacent fiber pairs 68, 70. Further, various shapes can be braided onto a surface of the longitudinal passage 30.

[0036] The sutures are typically braided of from 8 to 16 fibers. These fibers are made of nylon or other biocompatible material. It is envisioned that the suture 22 can be formed of multiple type of biocompatible fibers having multiple coefficients of friction or size. Further, the braiding can be accomplished so that different portions of the exterior surface of the suture can have different coefficients of friction or mechanical properties. The placement of a carrier fiber having a particular surface property can be modified along the length of the suture so as to place it at varying locations within the braided constructions.

[0037] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. For example, any of the above mentioned surgical procedures is applicable to repair of other body portions. For example, the procedures can be equally applied to the repair of wrists, elbows, ankles, and meniscal repair. The suture loops can be passed through bores formed in soft or hard tissue. It is equally envisioned that the loops can be passed through or formed around an aperture or apertures formed in prosthetic devices e.g. humeral, femoral or tibial stems. Such variations are not to be regarded as a departure from the spirit and scope of the invention.