Abstract:
A readily implantable knotless suture anchor that de-couples the angle of insertion of the anchor from the tissue passage step and other steps of conventional procedures. An anchor provides an internal locking mechanism configured such that: suture knots do not have to be tied; suture and tissue tension can be easily adjusted intraoperatively; and suture passage and tensioning can be done at a variety of positions and angles. A method includes: passing a first suture through a patient&#39;s tissue and then through a loop of a shuttle suture; pulling the free end of the shuttle suture until the first suture passes through an internal suture locking mechanism; applying tension in the first suture until adequate tension is achieved with respect to the tissue; automatically engaging an internal locking member; and securing the first suture against further relative movement with respect to the anchor.

Description:
[0001]    This application claims benefit of U.S. Provisional Application Ser. No. 61/605,962, filed Mar. 2, 2012, and Patent Cooperation Application No. PCT/US2013/028701 filed Mar. 1, 2013, and the entirety of such applications are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    In arthroscopic orthopaedic surgery, it is often necessary to reattach soft tissue to a boney structure. This occurs frequently in the shoulder and other tissues. In these situations where soft tissue is being reattached to bone, it is useful to use a suture anchor device to make the necessary repair. A suture anchor is typically placed into the bone and will not ordinarily pull out. Such suture anchor typically has sutures of its own that can be used to effectively reattach and tie down soft tissue to the bone. This reattachment allows the soft tissue to eventually heal to the bone, and during the process of healing, the suture anchor holds the tissue stationary on the bone. 
         [0003]    A suture anchor preferably resists gapping at the tissue bone interface and also resists cyclic loosening of the suture and the tissue from the bone. Anchors can be made of metal, plastic, or absorbable plastics, and designs vary with respect to the number of sutures provided and with respect to whether or not such sutures are allowed to slide within the anchor. 
         [0004]    In the normal use of suture anchors, the sutures are passed through the tissue and then knots are tied which allow the anchor to be held into place. A disadvantage can be that suture anchors are normally used for an arthroscopic situation where the anchor is being implanted into a joint where access is limited, and also, where fiber optic arthroscopic cameras are required for visualization by the surgeon. Tying knots in such circumstances can be laborious and time-consuming. 
         [0005]    Knotless anchors have been introduced in the surgical device market. However, such anchors may have certain technical pitfalls which the present invention seeks to remedy. 
         [0006]    The knotless anchors that have been produced to this point typically involve arthroscopically drilling a hole in a bone, removing the guide from that area, passing sutures through soft tissue. The surgeon must then re-find the hole and insert some sort of push-in anchor or screw-in anchor. As the anchor is screwed or pushed in, it varies as to how much tension is actually developed in the soft tissue. Certain joint geometries and locations make using these types of anchors difficult and/or less effective than desired. The process of drilling the hole and then having to re-find it after removing a specific guide (once the sutures have been passed through the tissue) is a technical difficulty for certain repair locations that have limited access. Additionally, using these types of anchors in certain locations can cause damage to adjacent tissue, which is undesirable. 
         [0007]    Accordingly, an anchor design which eliminates the need to tie knots and which provides internal cinching mechanisms would be desirable. 
       SUMMARY 
       [0008]    Generally, the present invention includes, in one embodiment, an easily implantable suture anchor that is knotless, and that de-couples the angle of insertion of the anchor from the tissue passage step and also other steps of the conventional procedure. The present invention anchor provides an internal locking mechanism configured such that: suture knots do not have to be tied; suture and tissue tension can be easily adjusted intraoperatively; and suture passage and tensioning can be done at a variety of positions and angles. 
         [0009]    In one exemplary use of the present invention, a surgeon would pass a first suture through the patient&#39;s tissue and then through a loop of a shuttle suture. The free end of a shuttle suture would then be pulled until the first suture passes through an internal suture locking mechanism constructed in accordance with the present invention. Tension would be applied in the first suture until adequate tension is achieved with respect to the tissue, and then the internal locking member automatically engages and secures the first suture against further relative movement with respect to the anchor. 
         [0010]    In another embodiment of an internal locking mechanism constructed in accordance with the present invention, the desired tension is applied in the first suture with respect to the tissue, and then the other end of a line or suture, i.e., a “locking limb,” is pulled in the opposite direction until the internal locking mechanism locks the first suture in place. 
         [0011]    In either case, excess suture extending outwardly from the tissue is then cut and removed. 
         [0012]    In another exemplary implementation of the present invention, an anchor for implantation in tissue and for use in cooperation with a suture is provided and includes a body member and a cleat connected to the body member that moves between a locking position and an unlocking position. The cleat engages the suture upon being in the locking position and generally fixes movement of the suture with respect to the body member. The cleat substantially permits relative movement between the suture and the body member upon being in the unlocking position, and the cleat automatically moves from the unlocking position to the locking position upon the suture being drawn in a predetermined direction, wherein the anchor is secured to the tissue. 
         [0013]    In another implementation, the apparatus further comprises a plurality of teeth being provided on the cleat for engaging the suture upon the cleat being in the locking position. 
         [0014]    A further exemplary implementation includes an anchor for implantation in tissue and for use in cooperation with a suture, comprising a body member and a snap lock mechanism connected to the body member that moves between a locking position and an unlocking position. The snap lock mechanism engages the suture upon being in the locking position and generally fixes movement of the suture with respect to the body member. Additionally, the snap lock mechanism substantially permits relative movement between the suture and the body member upon being in the unlocking position, and a line is connected to the snap lock mechanism that moves the snap lock mechanism from the unlocking position to the locking position upon the line being drawn in a predetermined direction, wherein the anchor is secured to the tissue. 
         [0015]    In another implementation of the present invention the snap lock device is conically shaped. 
         [0016]    The present invention also includes in an exemplary implementation a method for implantation of a suture anchor in tissue, comprising: providing a first suture; providing a shuttle suture; providing an internal suture locking mechanism having a suture lock; passing the first suture through the tissue and then through a loop of the shuttle suture; pulling the free end of a shuttle suture until the first suture passes through the internal suture locking mechanism; applying tension in the first suture until desired tension is achieved with respect to the tissue; and allowing the suture lock to automatically engage and secure the first suture against relative movement with respect to the anchor. 
         [0017]    Further, a method of the present invention may further comprise applying tension in the first suture with respect to the tissue from one end of the first suture, and through use of the other end of the first suture, pulling in the opposite direction until the suture lock locks the first suture against relative movement with respect to the anchor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The drawings referenced herein form a part of the specification. Features shown in the drawings are meant as illustrative of some, but not all, embodiments of the invention, unless otherwise explicitly indicated, and implications to the contrary are otherwise not to be made. Although in the drawings like reference numerals correspond to similar, though not necessarily identical, components and/or features, for the sake of brevity, reference numerals or features having a previously described function may not necessarily be described in connection with other drawings in which such components and/or features appear. 
           [0019]      FIG. 1  is a perspective view, with parts cut away, of a knotless suture anchor with an internal suture locking mechanism constructed in accordance with the present invention; 
           [0020]      FIG. 2  is a perspective view, with parts cut away, of an alternate embodiment of a knotless suture anchor with an internal suture locking mechanism constructed in accordance with the present invention; 
           [0021]      FIG. 3  is a plan view of a knotless suture anchor with an internal suture locking mechanism constructed in accordance with the present invention; and 
           [0022]      FIG. 4  is a sectional view of an alternate embodiment of a knotless suture anchor with an internal suture locking mechanism constructed in accordance with the present invention. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0023]    The accompanying drawings and the description which follows set forth this invention in several of its preferred embodiments. However, it is contemplated that persons generally familiar with surgical devices will be able to apply the novel characteristics of the structures illustrated and described herein in other contexts by modification of certain details. Accordingly, the drawings and description are not to be taken as restrictive on the scope of this invention, but are to be understood as broad and general teachings. 
         [0024]    Referring now to the drawings in detail, wherein like reference characters represent like elements or features throughout the various views, the knotless suture anchor with an internal suture locking mechanism (also referred to herein as “suture anchor” and as simply “anchor”) of the present invention is indicated generally in the figures by reference character  10 . 
         [0025]    As shown in  FIGS. 1-3 , suture anchor  10  includes a shell, generally  12 , which may be similar to conventional suture anchors. Shell  12  may include, in one preferred embodiment, a screw-in portion  14  having threaded portions  16  and/or a tap-in configuration (not shown) with either barbs or threads, based on whether anchor  10  is to be tapped in or screwed into the bone, generally B. 
         [0026]    Body member, or shell,  12  may be constructed of a non-absorbable plastic polymer, bioabsorbable plastic polymer, metal, or some other suitable and implantable material. An internal mechanism, generally  20 , of anchor  10  may include one or more high-strength braided nylon sutures, generally  22 , with one end of such suture  22  being fixed in the body, generally  24 , of anchor  10 . Such fixation of suture  22  to body  24  can be done in various ways. One way includes actually fusing suture  22  to a polymer portion of body  24 . Other ways may include using some sort of post, such as post  28 , about which suture  22  can be securely looped around and tied within anchor  10 . 
         [0027]    As shown in  FIG. 3 , in addition to suture  22 , anchor  10  may also include, in one preferred embodiment, a heavy monofilament nylon shuttle suture, generally  30 , placed in anchor  10 . Shuttle suture  30  has two free ends, one having a suture loop  32  which provides a shuttle through anchor  10 , once the loop  32  has been passed through tissue (not shown). Once loop  32  is passed through anchor  10  via a passage  33  defined by guide  34 , internal locking mechanism  20  then allows both the suture shuttle and the braided nylon suture  22  (which passes through loop  32  of shuttle suture  30 ) to be pulled through anchor  10  in a uni-directional fashion, with internal locking mechanism  20  cinching suture  22  by acting as an internal locking cleat  23 , wherein suture  22  can pass one way but not the other. Accordingly, as the free end of shuttle suture  30  is gradually pulled, it initially passes through internal locking mechanism  20 , but eventually, with continued pulling of shuttle suture  30 , suture  22  passes through internal locking mechanism  20  to ultimately cinch the tissue down (the tension may be adjusted in the tissue tension “rolling” tissue in either direction), such that the tissue is pulled down to the bone B in and/or near the suture anchor  10 . This allows re-approximation of the attachment of the tissue to the bone and allows adjustment of the tension both within suture  22 , and thus also the tissue to attach itself to bone B. 
         [0028]    Internal locking mechanism  20  can be of various configurations, and the present invention is not to be limited to the mechanisms disclosed and/or shown herein. Multiple other internal locking mechanisms could be used in anchor  10 , and the internal locking mechanisms disclosed and/or shown herein are for illustrative purposes and are not intended to limit the scope of the internal mechanisms that could be used in connection with anchor  10 . 
         [0029]    One variation of internal locking mechanism  20  could be a series of opposing resilient, directional barbs, or teeth,  20   a  which allow suture  22  to be pulled in between teeth  20   a  in only one, i.e., a “first” direction. An attempt to pull suture  22  in the other (“second”) direction would cause the teeth  20   a  to engage and hold suture  22  against further movement in the second direction. However, in the event suture  22  is again pulled in the first direction, teeth  20   a  would release suture  22  to allow suture  22  to again be pulled in the first direction. Internal locking mechanism  20  thus allows passage of sutures  30 ,  22  in one direction, but not in the opposite direction. 
         [0030]    Another variation of internal locking mechanism  20  could be an internal pre-tied locking knot, such as a hangman&#39;s noose knot  36 , as shown in  FIG. 2 . 
         [0031]    Still another variation (not shown) could be a woven suture inside a suture which once again allows uni-directional passage of the braided nylon suture. This could be a configuration similar to a Chinese finger trap type of device, which tightens against the suture moving in a predetermined direction. 
         [0032]    Other variations could include, but are not limited to, a conical locking mechanism, generally  40 , as shown in anchor  10 ′ in  FIG. 4 . Conical snap locking mechanism, generally  41 , includes a generally conical member  42  which is biased by weight and/or spring force towards a seat  44 . Although not shown, a strap, cable, line, or the like could be used to prevent member  42  from falling out of anchor  10 ′. Suture  22  may pass in a first direction whereby member  42  is caused to be lifted slightly above seat  44 , to thereby form a passage for suture  22 . If suture  22  is pulled in the other (“second”) direction, however, member  42  automatically moves downwardly, with neck portion  46  ultimately seating in a snap-fit, interference-fit arrangement with respect to seat  44  and engages suture  22  and fixes it against movement in the second direction. Similarly, as discussed above with respect to other versions of internal locking mechanism  20 , in use, the surgeon would pass suture  22  through the patient&#39;s tissue and then load suture  22  in and through loop  32 . The free end of shuttle suture  30  would then be pulled until suture  22  (moving in the first direction) passes through anchor  10 . Tension would be applied in suture  22  until adequate tension is achieved, and then the other free end of a second, line or suture,  50 , the “locking limb,” which has its other end connected to member  42 , is pulled in the second direction until the conical snap locking mechanism  41  locks suture  22  in place. Excess suture extending outwardly from the tissue is then cut and removed. 
         [0033]    Further, a cam mechanism (not shown) could be provides that flips back to lock upon itself in the event suture is pulled in reverse fashion. 
         [0034]    It is to be understood that the above various internal locking mechanism configurations could be used either singularly or in combination with one another in a given anchor  10 , if desired. 
         [0035]    Conventional anchor knotless anchor designs generally marry the angle of insertion of the anchor to a portal, since the anchor has to be placed through the portal, and then suture passage through tissue must be achieved. At this point, the anchor position must be re-found through the same portal. Then, the tissue is cinched down. However, for certain positions, in the shoulder in particular, this creates a technical problem, because frequently it is in an inappropriate location to place a portal. For example, in repairing a superior labrum or SLAP lesion, anchors are frequently placed percutaneously through the rotator cuff. It is advantageous in this situation to make these perforations through the rotator cuff as small as possible. However, normally a 6-8 mm diameter cannula is required to be inserted through this tissue in order to position conventional cinching knotless suture anchor designs. 
         [0036]    With anchor  10  of the present invention, anchor  10  could be placed percutaneously through a 3 or 4 mm hole, and then the surgeon would have the freedom to pass the suture through tissue in a variety of other angles within the shoulder. This would likely minimize damage to the adjacent tissue, particularly with respect to the rotator cuff noted in the example above. Labral repair is but one application of the present invention. Anchor  10  could also be used in other repairs, such as rotator cuff repair in the shoulder, biceps tenodesis, and a myriad of other procedures in the shoulder and elsewhere. Anchor  10  could be used in any other joint in the body in which suture anchor placement is required for soft tissue fixation to bone. 
         [0037]    In short, anchor  10  provides a versatile device which could be used in the shoulder, in particular, and for numerous other applications in the musculoskeletal system to facilitate soft tissue fixation to bone, with minimal suture damage. The present invention may find particular applications in procedures involving the: shoulder (labrum, rotator cuff, biceps tenodesis, etc.); knee (backup hamstring fixation, MCL/LCL reconstruction, ligament avulsions, etc.); elbow (UCL/LUCL reconstruction, biceps, etc.); foot and ankle; and wrist. The present invention also provides a lower profile by eliminating prominent knots on articulating surfaces. 
         [0038]    Aspects of the present invention may include a braided nylon suture with one end fixed to an anchor, a heavy monofilament nylon suture shuttle, internal locking mechanisms with multiple variations, and a simplified methodology of how a knotless suture anchor with an internal suture locking mechanism may bye constructed in accordance with the present invention might be inserted and used. Also disclosed is a simplified technique for insertion and use of an anchor of the present invention. For example, in methods disclosed herein, suture  22  can be single or double loaded as applicable. 
         [0039]    Anchors  10 ,  10 ′ can be produced in various diameters, including without limitation, diameters between approximately 2 and 6 millimeters. 
         [0040]    The present invention thus provides, among other things, the potential of decreased surgical time, increased surgical accuracy, a decreased dependence on knot-tying and loosening, lower profile by eliminating prominent knots on articulating surfaces. 
         [0041]    Specifically, the knotless anchor of the present invention may be inserted through drilling cannula (which reduces the likelihood of losing the hole), and a “normal” suture passage may be used. Also, tissue tension may be adjusted by “rolling” tissue in either direction. This can thus address problems which may occur with current anchor designs, such as losing the hole in the methodology where a hole is drilled, and the devise is removed. Then, the hole must be relocated. This can pose particular difficulty in relation to the lower glenoid quadrants. Additionally, the angle of insertion of such a conventional anchor may be married to a working portal. Moreover, with such designs, it may be difficult to manipulate tissue and a suture is tensioned. 
         [0042]    In one exemplary implementation, anchor  10  may include a standard tap-in or screw-in insertion that permits drilling and insertion through the same cannula, which may be 3.0 to 4.5 mm cannula, and as noted above, the anchor may be single or double loaded. Anchor  10  may include suture  22  being a wire fixed on one end in the anchor and with a free end. A heavy nylon suture shuttle may be preloaded, and an internal locking mechanism may include a cleat, a locking knot, and a Chinese finger trap type device. Other variations of the present invention could include a Chinese finger trap type device including a suture-in suture with unidirectional tensioning, an internal cam, and a second suture to lock a know when adequate tension has been obtained. 
         [0043]    While preferred embodiments of the invention have been described using specific terms, such description is for present illustrative purposes only, and it is to be understood that changes and variations to such embodiments, including but not limited to the substitution of equivalent features or parts, and the reversal of various features thereof, may be practiced by those of ordinary skill in the art without departing from the spirit or scope of the present disclosure.