Abstract:
Embodiments of the invention include methods and devices for securing a suture, graft, or other material to tissue with an anchor. The anchor of some embodiments includes an eyelet through which the suture, graft, or other material may be passed and mechanisms for selectively engaging the suture, graft, or other material through the eyelet. The mechanisms of some embodiments may also reinforce the anchor to provide a strengthened anchor to withstand actions such as impacting the anchor during insertion or applying bending stress to the anchor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of pending U.S. application Ser. No. 62/100,108, filed Jan. 6, 2015, the disclosure of which is incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of tissue anchors, and more particularly relates to knotless suture anchors or tissue anchors along with their implantation instruments and related methods. Some embodiments include an anchor and an implantation instrument with a portion of the instrument that both strengthens the anchor during implantation and selectively impinges on a suture or tissue graft to be attached with the anchor. 
       BACKGROUND 
       [0003]    Anchors used to secure sutures, tissue grafts, or other components are ideally as small as possible while providing sufficient strength for their designed task. Smaller size may be advantageous to one or both decrease surgical trauma and to enable implantation in smaller anatomical structures. In some circumstances, such as but not limited to when an anchor is used in a knotless anchoring system where no guide instrument is provided, high stresses may be created in an anchor during implantation. Impacting, positioning, or repositioning of anchors may also create high stresses in an anchor. A specific non-limiting example of creating relatively high stresses in an anchor is when the anchor is used as a pivot point to lever a humeral head to gain an effective trajectory for implantation. In such a circumstance, an anchor that would be strong enough to meet load requirements of the anchor in a completed construct may not be of adequate strength to withstand the loads generated when being used as a pivot point. One way of addressing the need for a stronger anchor during implantation is to just use a larger diameter anchor. However, use of a larger diameter anchor may create additional surgical trauma and may not fit a patient&#39;s available anatomic implantation site in some circumstances. 
         [0004]    It would be advantageous to provide an anchor that is of a relatively small size that may be strengthened or reinforced during implantation. Particular instrumentation and methods may also be required to implant such an anchor. It may be further advantageous to provide a portion of an implantation instrument that is capable of both strengthening or reinforcing an anchor and selectively engaging and disengaging suture or tissue that the anchor is used to attach. 
       SUMMARY 
       [0005]    An embodiment of the invention is an anchor system that includes an anchor with an opening through its proximal end and an eyelet through the anchor that is transverse with and intersects the opening. The anchor system may also include an inserter that includes an outer shaft configured to contact the anchor and to be used to push the anchor into tissue, and a rod configured to fit within the outer shaft and move within the outer shaft and to move within the anchor when the outer shaft is in position to push the anchor into tissue. The rod may be configured to go through the opening in the proximal end of the anchor and to occlude the eyelet when advanced distally within the anchor. The rod may also support and improve the strength of the anchor system when advanced distally within the anchor. 
         [0006]    Another embodiment of the invention is a method of anchoring to tissue. The method may include providing an anchor with an opening through its proximal end and an eyelet through the anchor that is transverse with and intersects the opening, and providing an inserter that includes a rod configured to fit within the anchor. The method may also include passing a suture through the eyelet, advancing the rod distally through the opening in the anchor far enough to occlude the eyelet, pushing the anchor into tissue at least as far as the proximal end of the anchor after the rod has been advanced distally through the opening in the anchor far enough to occlude the eyelet, and removing the rod proximally through the opening in the anchor. 
         [0007]    Still another embodiment of the invention is a method of securing a suture to a bone that includes passing a suture through an eyelet in an anchor and engaging an inserter with the anchor and the suture to positively hold the suture relative to the anchor. The method embodiment may also include pushing the anchor into the bone with the inserter such that the suture is wedged between the anchor and the bone, thereby substantially preventing movement of the suture relative to the anchor, and removing the inserter from the anchor, leaving the anchor and the suture secured in the bone. 
         [0008]    Yet another embodiment of the invention is a method of securing a suture to a bone that includes coupling the suture to an anchor system. The anchor system may include an anchor with an opening through its proximal end and an eyelet through the anchor that is transverse with and intersects the opening, and an inserter comprising an outer shaft configured to contact the anchor and to be used to push the anchor into tissue, and a rod housed within the outer shaft and the anchor, the rod extending through the opening in the proximal end of the anchor and configured to occlude the eyelet when advanced distally within the anchor. The method embodiment may further include pushing the anchor into the bone with the inserter such that the suture is wedged between the anchor and the bone, thereby substantially preventing movement of the suture relative to the anchor, and removing the inserter from the anchor, leaving the anchor and the suture secured in the bone. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of an anchor through which sutures have been passed where the anchor is coupled to an inserter. 
           [0010]      FIG. 2  is a side elevation view of the anchor and sutures of  FIG. 1  and a distal end of the inserter of  FIG. 1 . 
           [0011]      FIG. 3  is a cross-sectional view of the anchor, sutures, and distal end of the inserter of  FIG. 1  with components in the relative positions illustrated in  FIG. 2 . 
           [0012]      FIG. 4  is a cross-sectional view of the anchor of  FIG. 1 . 
           [0013]      FIG. 5  is a cross-sectional view of the anchor and distal end of the inserter of  FIG. 1 . 
           [0014]      FIG. 6A  is a cross-sectional view of the anchor, sutures, and distal end of the inserter of  FIG. 1  being prepared to be implanted in tissue by advancing a portion of the inserter distally within the anchor. 
           [0015]      FIG. 6B  is a cross-sectional view of the anchor, sutures, and distal end of the inserter of  FIG. 1  being prepared further to be implanted in tissue by advancing a portion of the inserter further distally within the anchor. 
           [0016]      FIG. 6C  is a cross-sectional view of the anchor, sutures, and distal end of the inserter of  FIG. 1  having been implanted in tissue by pushing the anchor, sutures, and inserter into tissue. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    An embodiment of an anchor system  100  and its component parts and methods of implementation are illustrated in  FIGS. 1-6C . As depicted in  FIG. 1 , the anchor system  100  includes an anchor  10 , an inserter  20 , and sutures  30 ,  31 . An embodiment of the anchor  10  is shown in  FIGS. 1-6C . As most clearly seen in  FIG. 4 , the anchor  10  includes an opening  11  through its proximal end  12  and an eyelet  13  through the anchor  10  that is transverse with and intersects the opening  11 . The opening  11  shown is cylindrical and includes a thread  17  around a proximal, interior portion of the opening  11 . Openings of other embodiments may be of any other effective shape, and in addition to or instead of threads may include any other effective coupling mechanism, such as without limitation, a ball and detent, a clamp, or a snap ring. The opening  11  depicted is a partial cannulation that does not exit a distal end of the anchor. In other embodiments, an opening could include a full cannulation of the anchor or a cannulation that varies in shape or length from the shape and length of the opening  11 . The anchor  10  shown includes protrusions  16  positioned around the exterior of the anchor  10  that are configured to create resistance to pull-out of the anchor  10  from tissue. As used herein, the term “tissue” may include any portion of the human body, including but not limited to bones, tendons, ligaments, cartilage, and periosteal components. The protrusions  16  shown are of a raked tooth shape. However, any effective shape may be used in other embodiments. For example and without limitation, protrusions may be triangular, square, pyramid shaped, shark&#39;s tooth shaped, and raked to a greater or lesser degree. The anchor  10  shown includes a basin  15 . The basin  15  illustrated extends distally beyond a most distal portion of the eyelet  13 . 
         [0018]    As shown in  FIG. 5 , the basin  15  is configured to receive a rod  24  that is part of the inserter  20 . The rod  24  may pinch the suture  30 ,  31  relative to the anchor  10  within the basin  15 . The rod  24  may also, or in the alternative reinforce, strengthen, and support the anchor  10  by providing support for the anchor  10  within the opening  11 , within the basin  15 , and throughout the partial cannulation of the anchor  10 . In the position shown in  FIG. 5  where the rod  24  is advanced distally within the anchor  10  beyond a most distal portion of the eyelet  13  within the basin  15 , the rod  24  supports and improves the bending strength of the anchor  10 . Embodiments of a rod of the anchor system may be more generally described as supporting and improving the strength of the anchor system, whether in bending or otherwise, when the rod is position within or advanced distally within the anchor. 
         [0019]    The inserter  20  includes an outer shaft  22  configured to contact the anchor  10  and to be used to push the anchor  10  into tissue. The contact between the outer shaft  22  and the anchor  10  may be an abutment, as shown in  FIGS. 1-3 and 5-6C , or the contact may be a coupling capable of transmitting one or more of tensile, compressive, torsional, and lateral forces. The contact may be selectively attachable and detachable in some embodiments by any effective mechanism. In some embodiments, the anchor system  100  may include a stay suture (not shown) that connects between the inserter  20  and the anchor  10 . The stay suture may be tensioned to urge the anchor  10  toward the inserter  20  during insertion and then released when the inserter  20  is removed from the anchor  10 . A stay suture may be removed from the anchor  10  by pulling one end of the stay suture entirely through the anchor  10 , by severing the stay suture, or by any effective mechanism of removal. An extension shaft  21  is depicted in  FIG. 3  proximal of and partially surrounding the outer shaft  22  and the rod  24 . The inserter  20  illustrated also includes the rod  24  configured to fit within the outer shaft  22  and move within the outer shaft  22  ( FIGS. 3 and 5-6C ). The rod  24  is also configured to move within the anchor  10  when the outer shaft  22  is in position to push the anchor  10  into tissue. The rod  24  may be made from any functional material, but in some embodiments is made at least in part from a metal with a greater bending strength than the material from which the anchor is made. In other embodiments, a rod may be made from a material that is of the same or a lesser bending strength than an anchor. In such a case, the additional material of the rod may give the combined construct enough additional strength to meet design requirements that the anchor would not meet alone. 
         [0020]    Embodiments of the rod  24  are configured to go through the opening  11  in the proximal end  12  ( FIG. 4 ) and to occlude the eyelet  13  when advanced distally within the anchor  10 . The rod  24  is shown at various stages of advancement distally within the anchor  10  in  FIGS. 5-6C . Specifically, the rod  24  is shown partially occluding the eyelet  13  in  FIG. 6A . In  FIGS. 5, 6B, and 6C , the rod  24  has been advanced further distally within the anchor  10  and is fully occluding the eyelet  13 . The rod  24  and the anchor  10  are configured to removably couple to one another. In particular, the exterior of the rod  24  illustrated in  FIG. 5  includes a thread  27  and the interior of the anchor  10  includes the thread  17 , which matches the thread  27  such that rotating the rod  24  within the anchor  10  moves the rod  24  within the anchor and exercises a removable coupling between the rod  24  and the anchor  10 . As used herein, the term “removably couple” or “removable coupling” means that the components are more positively and controllably attach together than components that merely abut or slide relative to one another. The illustrated embodiment depicts movement of the rod  24  relative to the anchor  10  by rotation of the rod  24 . The rod  24  may be rotated by a knob or other mechanism that is a part of the inserter  20  and connects to the rod  24 . Other embodiments may enable relative movement between a rod and an anchor or similar components by any effective mechanism, whether it be manual or powered by any operative source. 
         [0021]    As shown in  FIGS. 1-3 and 5-6C , the anchor system includes sutures  30 ,  31  configured to pass through the eyelet  13 . In various embodiments, one or any number of sutures may be passed through an eyelet to achieve surgical objectives, as limited only by the sizes of the sutures and eyelet. The sutures  30 ,  31  are shown as two separate sutures, but in some embodiments may be a single suture doubled over and passed through an eyelet. A suture of the anchor system may be any suture, for example and without limitation, the suture may be a monofilament, multistrand, or woven construct. In some embodiments, the anchor system may be used to attach a tissue graft to another tissue element. For example and without limitation, the anchor system may be used to attach a ligament graft to a bone. In this example, the ligament graft or multiple grafts may be passed through an eyelet of an anchor, coupled with the assistance of a rod, and pushed into a bone in an essentially similar manner to the illustrated suture. 
         [0022]    An embodiment of the invention is a method of anchoring tissue. The embodiment may include providing an anchor with an opening through its proximal end and an eyelet through the anchor that is transverse with and intersects the opening. For example, the anchor  10  with opening  11  and eyelet  13  may be used in conducting the method. The embodiment may also include providing an inserter that includes a rod configured to fit within the anchor. The inserter  20  with rod  24  and outer shaft  22  as described herein is an example of an inserter device that may be used. The method embodiment may include passing a suture, such as the sutures  30 ,  31  through the eyelet  13 , as depicted in  FIGS. 1-3 . In this illustration, multiple sutures  30 ,  31  have been passed through the eyelet, but in other embodiments a single suture or one or more tissue grafts may be passed through the eyelet  13 , or a similar eyelet. A suture may be passed through an anchor while the anchor is outside of a patient&#39;s body, or in some cases may be passed when the anchor is in whole or in part within a joint or other subcutaneous portion of a patient&#39;s body. 
         [0023]    Method embodiments may further include advancing a rod, such as the rod  24 , distally relative to the anchor  10 . In particular in the example shown in  FIGS. 5 and 6B , the rod  24  has been advanced distally through the opening  11  in the anchor  10  far enough to occlude the eyelet  13 . In some embodiments, prior to the act of advancing the rod  24  distally through the opening  11  in the anchor  10  far enough to occlude the eyelet  13 , the rod  24  is advanced toward a distal end of the eyelet  13 , but not far enough to impinge on the suture. An example of this act is illustrated in  FIG. 6A . In this state, the suture  30 ,  31  may remain free to move relative to the anchor  10  while the anchor is positioned in vivo. As shown in  FIG. 6A , the anchor  10  has been place adjacent to tissue  200 , which has a pre-drilled hole  201  into which the anchor may be pushed. The tissue  200  may be, for example and without limitation, a bone with an outer cortical layer covering a cancellous core. In the example anchoring system  100  shown in  FIGS. 1-4 and 5-6C , the act of advancing the rod  24  distally through the opening  11  in the anchor  10  includes turning the rod  24  relative to the outer shaft  22  and the anchor  10 , as described in more detail herein. As shown in  FIGS. 5, 6B, and 6C , the rod  24  may also be advanced into the basin  15  formed in the anchor  10  distal of the eyelet  13 . This act may secure the sutures  30 ,  31  relative to the anchor  10  by pinching the sutures between the eyelet  13  and the rod  24 . This act may also or in the alternative increase the strength of the anchor system compared with the anchor  10  alone. 
         [0024]    Another act of the method embodiment described here may include pushing an anchor, such as the anchor  10 , into tissue, such as the tissue  200 , at least as far as the proximal end  12  ( FIG. 4 ) of the anchor  10  after the rod  24  has been advanced distally through the opening  11  in the anchor  10  far enough to occlude the eyelet  13 . The result of this act is illustrated in  FIG. 6C . The act of pushing the anchor  10  into the tissue  200  may also result in the suture being wedged between the anchor  10  and the tissue  200 . As shown in  FIGS. 6A-6C , method embodiments may also include the act of pre-drilling a hole  201  in the tissue  200  into which the anchor  10  may be pushed. In other embodiments, an anchor may be a push-in device that has a sharpened distal end or a tapping or drilling configuration that enables the anchor to be push into tissue without a hole being pre-drilled into the tissue. Such an anchor device may in some embodiments be made from metal or have a metal tip that may be sharpened or otherwise formed to promote its push-in functionality. 
         [0025]    The rod  24 , or a similar rod in other embodiments, may be removed proximally through the opening  11  in the anchor  10 . In the illustrated embodiment, the rod  24  may be removed from the anchor  10  by rotating the rod  24  in a counterclockwise direction relative to the anchor  10  and then pulling the rod  24  and outer shaft  22  proximally away from the anchor  10 . Once the anchor system  100  is in place as illustrated in  FIG. 6C , the frictional resistance of the anchor  10  in the hole  201  in the embodiment shown is sufficient to allow the rod  24  to be rotated counterclockwise to move the rod  24  proximally away from the anchor  10 , and subsequently to pull the rod  24  and outer shaft  22  away from the anchor  10 . In other embodiments (not shown) a rotational constraint may be provided between an anchor and an inserter to positively lock movement between the anchor and the inserter while a rod is rotated or otherwise disengaged from the anchor. These acts will leave the anchor  10 , along with the sutures  30 ,  31 , implanted in the tissue  200 . The sutures  30 ,  31  may then be carried forward to another anchor or to tissue to be surgically manipulated, may be cut, or may be knotted in some circumstances. 
         [0026]    Another method embodiment is a method of securing a suture to a bone that also includes passing a suture through an eyelet in an anchor. The suture passing variations and example sutures, grafts, and anchor configurations are essentially similar to those describe in the method embodiment above. The method may also include engaging an inserter, such as the inserter  20 , with an anchor, such as the anchor  10 , and a suture to positively hold the suture relative to the anchor  10 . The term “to positively hold” as used herein means to secure with a consistent force as applied by a clamp or threaded member and not merely to press on a suture with an unsecured and variable force as may be applied with an inserter held in a user&#39;s hand. As described with regard to the rod  24  and the anchor  10  herein, the act of engaging an inserter with the anchor  10  and the sutures  30 ,  31  to positively hold the sutures  30 ,  31  relative to the anchor  10  may include advancing a portion of the inserter  20 , such as the rod  24 , by turning the rod  24  relative to the outer shaft  22  and the anchor  10 . The act of engaging an inserter with the anchor  10  may further include advancing a portion of the inserter  20 , such as the rod  24 , into the basin  15 , as shown in  FIGS. 5, 6B, and 6C , and as described in more detail in association with the method embodiment above. Descriptions and variations of this method are essentially similar to those describe with the method embodiment above with regard to wedging of the suture between an anchor and a bone, and with regard to acts associated with pre-drilling of holes into which an anchor may be pushed. 
         [0027]    Method embodiments may include but are not limited to securing a suture to bone in performing a rotator cuff repair consistent with the acts described herein. In particular, the anchor system  100  may be used to secure a suture, such as the sutures  30 ,  31  to a humerus where one or both of the sutures  30 ,  31  have been attached to soft tissues of the rotator cuff. In the particular example of a double-row rotator cuff repair, an anchor  10  of the anchor system  100  may be used to secure one or more sutures to a humerus underneath soft tissues of the rotator cuff. The anchor  10  may also be used to secure one or more sutures into a humerus distal of the soft tissues of the rotator cuff. A common suture may be passed between and coupled to two or more anchors of such a construct or multiple sutures may be combined by tying or by coupling to two or more anchors. 
         [0028]    Other method embodiments may include use of devices disclosed herein to perform a labral repair. For example and without limitation, one or more anchors  10  may be inserted into a glenoid bone. Sutures  30 ,  31  attached to the anchors may then be used to re-attach the labrum to the bone. A typical labral repair may require  1 ,  2 ,  3 , or more anchors, depending on the location and size of the tear being repaired. After the one or more anchors  10  are placed, the sutures  30 ,  31  may be run through the labrum and then pulled tight to re-attach the labrum to the glenoid. A common suture may be passed between and coupled to two or more anchors of such a construct or multiple sutures may be combined by tying or by coupling to two or more anchors. 
         [0029]    Various embodiments of a system wholly or its components individually may be made from any biocompatible material. Instruments that will not be implanted and remain in a patient may not necessarily be biocompatible. For example and without limitation, materials may include in whole or in part: non-reinforced polymers, reinforced polymers, metals, ceramics, adhesives, reinforced adhesives, and combinations of these materials. Reinforcing of polymers may be accomplished with carbon, metal, or glass or any other effective material. Examples of biocompatible polymer materials include polyamide base resins, polyethylene, Ultra High Molecular Weight (UHMW) polyethylene, low density polyethylene, polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), a polymeric hydroxyethylmethacrylate (PHEMA), and polyurethane, any of which may be reinforced. Example biocompatible metals include stainless steel and other steel alloys, cobalt chrome alloys, zirconium, oxidized zirconium, tantalum, titanium, titanium alloys, titanium-nickel alloys such as Nitinol and other superelastic or shape-memory metal alloys. Sutures or other similar components of the invention may be single strand, woven, braided, or any combination thereof from any of these or other biocompatible materials. The sutures or other similar components may be any effective natural or synthetic material and may be a use or combination of materials well-known in the art. Sutures or other similar components of various embodiments may be resorbable or not resorbable. 
         [0030]    Terms such as proximal, distal, far, underneath, and the like have been used relatively herein. However, such terms are not limited to specific coordinate orientations, distances, or sizes, but are used to describe relative positions referencing particular embodiments. Such terms are not generally limiting to the scope of the claims made herein. Any embodiment or feature of any section, portion, or any other component shown or particularly described in relation to various embodiments of similar sections, portions, or components herein may be interchangeably applied to any other similar embodiment or feature shown or described herein. 
         [0031]    While embodiments of the invention have been illustrated and described in detail in the disclosure, the disclosure is to be considered as illustrative and not restrictive in character. All changes and modifications that come within the spirit of the invention are to be considered within the scope of the disclosure.