Abstract:
A deformable or flexible suture anchor having apertures secures a suture to a skeletal structure via holes drilled through the skeletal structure, and passing the suture therethrough. A deformable structure permits the anchor to resiliently deform or bend for passing through an aperture, and resume a size larger than the passed aperture for securement on an opposed side of the aperture.

Description:
RELATED APPLICATIONS 
       [0001]    This patent application claims the benefit under 35 U.S.C.§119(e) of U.S. Provisional Patent Application Nos. 61/769,400, filed Feb. 26, 2013, entitled “SUTURE BASED HEADED TACK,” and 61/861,530, filed Aug. 2, 2013, entitled “KNOTLESS SUTURE ANCHOR,” both incorporated herein by reference in entirety. 
     
    
     BACKGROUND 
       [0002]    Endoscopic surgical techniques frequently involve physical attachment to human skeletal joint structures. Sutures are often employed for securing reconstructive appliances to the skeletal structures. Sutures may also be employed to replace or supplement flexible connective tissue, such as tendons and ligaments. It is therefore desirable to securely attach the sutures to the skeletal structures such that the sutured attachment can withstand movement of the skeletal structures. Attachment mechanisms may vary based on the rigidity of the skeletal structure, since a hard bone surface withstands more force than a softer connective tissue, which is more prone to tearing or pulling through a suture attachment. 
       SUMMARY 
       [0003]    Reconstructive surgery often employs surgical attachment techniques using a suture secured to a rigid skeletal member such as a bone or cartilage structure. Often soft tissue structures are adjacent and may need to be drilled, evacuated or otherwise accommodated. A deformable or flexible suture anchor having a plurality of apertures secures a suture to a skeletal structure via holes drilled through the skeletal structure, and passing the suture therethrough. A deformable structure permits the anchor to resiliently deform or bend for passing through an aperture, and resume a size larger than the passed aperture for securement on an opposed side of the aperture. 
         [0004]    In a particular configuration, the suture anchor has a crossmember between the plurality of apertures (typically two) such that a continuous suture passes through both apertures and around the crossmember forming a loop, and through the holes in the skeletal structure. The suture anchor may be disposed through the skeletal hole with an insertion device for inserting the anchor along a smaller dimension (i.e. along its width) for transverse orientation following insertion. Since the transverse or rotated suture anchor is larger than the holes in the skeletal structure (i.e. bone), the suture anchor is drawn and engaged to the skeletal structure when the suture is contracted or pulled through the hole(s). The suture anchor binds the suture to the bone as the loop is pulled tight around the crossmember and forms a “T” with the suture as the length of the anchor is drawn against the surface of the skeletal member and perpendicular to the suture. The contoured anchor shape of the proposed approach facilitates mating with a skeletal structure and reinforcing areas of greatest strain, i.e. having a wider structure around the suture holes. Distal ends of the suture passed through the holes are then secured by any suitable means to maintain the suture taut and the suture anchor engaged by the suture looped around the crossmember. 
         [0005]    In other contexts, it would be beneficial to provide a surgical anchor that can be inserted with a single insertion motion from a corresponding appliance, and which employs a knotless design cinchable by tension on a single suture strand. Unfortunately, conventional approaches suffer from the shortcoming that suture anchors are either all suture (anchor constructed itself of suture material) or knotless, but not both. The disclosed approach merges these approaches to define an all suture knotless anchor, capable of being delivered trans tissue. Features of the disclosed approach include the following: knotless design, radio lucent, all suture material construction, and provides a low profile suture pledget having a larger contact area under the pledget compared to standard anchors. 
         [0006]    In another configuration, a knotless suture anchor as disclosed herein includes a cannulated suture forming a loop, in which the cannulated suture has a tubular wall defining an opening at an end of the suture, and the opening provides communication with a cannulated interior. The loop is defined by segment of the suture passed through the opening and into the cannulated interior a short distance and then passed out through a void in the tubular wall. A woven or mesh construction of the tubular wall permits passage to complete the looping in a so-called “finger trap” manner. The suture anchor is integrated with the cannulated suture, via a woven or mesh integration, such that the suture anchor is adapted for fixation at a surgical site. The pledget takes the form of a fixation member having an engagement surface, such as a substantially flat or planer surface facing the suture anchor and a plurality of apertures through which the suture loop passes, in which the loop engaging the apertures for drawing the engagement surface toward the suture anchor via tightening of the loop. Depending on the construction of the suture anchor, the engagement surface may be irregular or resilient, as in the case of a suture material anchor. In this manner, the surgical attachment is provided for tissue disposed between the engagement surface and the anchor. 
         [0007]    In another configuration, a method of surgical attachment includes disposing a suture anchor through a surgical aperture, such that the suture anchor is compressibly deformable for permitting passage through the surgical aperture, and securing the suture anchor against the surgical aperture by restraining the suture anchor against the surgical aperture. The suture anchor deformability prevents subsequent passage through the surgical aperture. The suture anchor may be secured by drawing a suture strand through the surgical aperture and tightly against surgical tissue. Alternatively, securing may involve passing a distal end of a cannulated suture through a plurality of apertures in a fixation member, in which the fixation member has an engagement surface, and the cannulated suture has a tubular wall defining an opening at distal and proximate ends of the suture and an interior void defined by the cannulated interior. The method includes integrating a suture anchor into the tubular wall of the suture, the suture anchor adapted for fixation at a surgical site, and forming a loop in the cannulated suture, the opening providing communication with a cannulated interior, the loop defined by passing the suture passed through the opening into the cannulated interior and passed through a void in the tubular wall. A surgeon passes the distal end of the suture through at least one of the apertures in the fixation member and adjacent to the loop, and draws the engagement surface toward the suture anchor via tightening of the loop, the surgical attachment provided for tissue disposed between the engagement surface and the anchor. 
         [0008]    The above configurations of deformable anchors may be employed individually or together, for example combining the knotless anchor with the deformable anchor as the pledget. Alternatively, the knotless anchor may be employed with a more rigid structure, also referred to as an ENDOBUTTON®, marketed commercially by Smith and Nephew, of Memphis, Tenn. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
           [0010]      FIG. 1  shows a top view of the deformable suture anchor; 
           [0011]      FIG. 2  shows a side view of the suture anchor of claim  1  engaged by a suture; 
           [0012]      FIG. 3A  shows the deformable suture anchor deployed in a recess; and 
           [0013]      FIG. 3B  shows the deformable suture anchor deployed through a bone tunnel. 
           [0014]      FIG. 4  shows a side view of the knotless suture anchor assembly as disclosed herein; 
           [0015]      FIG. 5  shows a cutaway view of a knotless suture and anchor assembly following surgical insertion; and 
           [0016]      FIG. 6  shows the integration of the cannulated suture and the suture anchor; 
           [0017]      FIGS. 7A and 7B  show respective undeformed and deformed (compressed) suture anchors of the configuration of  FIG. 1-3B ; and 
           [0018]      FIG. 8A-8B  show respective undeformed and deformed (compressed) configurations of  FIGS. 4-6 . 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Depicted below are various configurations of the proposed approach. The deformable anchor may be of any suitable deformable and/or resilient material, such as textile, plastic or rubber.  FIG. 1  shows a top view of the deformable suture anchor  100 . 
         [0020]    The suture anchor body  102  has a plurality of apertures  111 - 1 ,  111 - 2  ( 111  generally) suitable for suture passage. The suture anchor therefore includes a body  102  having a plurality of apertures  111 - 1 ,  111 - 2  extending therethrough, such that the apertures are adapted for passing suture. The body  102  includes at least one crossmember  119 , defined by the region between the apertures  111 , such that the crossmember  119  is adapted for engagement with a suture loop  142  from a suture passed through at least two of the apertures  111 , discussed further below with respect to  FIG. 2 . The body  102  may have an irregular and/or non-linear edges, due to construction of a resilient material such as textile, suture, or other flexible and/or deformable material, discussed further below. 
         [0021]    The body  102  includes a flexible portion  125 , adapted to deform along dotted line  132 , for deforming the anchor  100  for insertion in a skeletal aperture, such that the flexible portion  125  is configured to return to an undeformed shape subsequent to insertion, in which the undeformed shape is unsuitable for passage through the skeletal aperture through which the deformed anchor  100  was passed. The flexible portion  125  may be part of the crossmember  119 , and the body  102  may have a cutaway or more flexible portion at the dotted line  132  for facilitating a fold or other deformation in the anchor  100 . Alternatively, the body  102  may be passed substantially undeformed in a lengthwise manner such that upon emerging, rotates 90 degrees for engaging a longitudinal side against the skeletal aperture. The undeformed anchor  100  is shown elongated and the deformed anchor folds substantially at a midsection defined by the dotted line  132 . Once deployed, the anchor unfolds or undeforms, discussed below in  FIG. 3 . 
         [0022]      FIG. 2  shows a side view of the suture anchor  100  of claim  1  engaged by a suture  121 . The suture  121  passes through and emerges back to a common side  103  of the suture  121 , thus defining a suture loop  142  on an opposed side  104 . The suture loop  142  engages the crossmember  119  between the apertures  111 - 1 ,  111 - 2  for securing the suture on the opposed side  104 . The suture  121  is knotted, secured in an anchor, or fixed by other suitable means from the common side  103 . 
         [0023]      FIG. 3A  shows the deformable suture anchor deployed in a recess  150 , such as a drilled hole. Referring to  FIGS. 1-3B , in a particular arrangement, the body  102  is pulled against a surgical surface  144  or bone such that compression builds in the suture  121  due to the resilient nature of the body  102 . A further resilient layer  146  may be provided between the body  102  and the surgical surface  144  for providing optimal compression forces and/or dispersion against the surgical surface  144 . Suture ends  141 - 1 ,  141 - 2  ( 141  generally) are secured in a conventional anchor  152  for maintaining the compression force through tension in the suture  121 . The deformable anchor  100  may be of any suitable deformable and/or resilient material, such as textile, plastic or rubber. The anchor  150  is disposed in a sufficiently firm material (i.e. bone) so as to adequately resist the tension from the suture  121 . The surgical surface  144  may be a similar or less rigid surface such as tendons, ligaments or other connective or soft tissue. 
         [0024]      FIG. 3B  shows the deformable suture anchor deployed through a surgical aperture such as a bone tunnel  160 . Following deformation for passage through a drilled hole or attachment to a recess, the body  102  returns to the undeformed shape disposing the elongated side of the anchor normal (lengthwise) to an axis  162  of the surgical aperture. The deformed body  102  is passed through the bone tunnel  160  by any suitable means, and undeforms (returns to undeformed state) upon emerging on the surgical surface  144 . The suture  121  remains fixed by engagement with the crossmember  120  and the tension on the suture ends  141 - 1 ,  141 - 2 , which are secured by any suitable means, such as knotting or anchoring, at a distal end of the bone tunnel away from the anchor  100 . The undeformed anchor  100  thus has a length greater than a diameter of the surgical aperture defined by the bone tunnel  160 , and therefore remains fixed, forming a “T” engagement with the suture  121  against the surgical surface  144 . 
         [0025]    Depicted below are various configurations of an alternate configuration of the proposed approach for a non-rigid knotless suture anchor.  FIG. 4  shows a side view of a knotless suture and anchor assembly  101  as disclosed herein. The knotless suture anchor assembly  101  includes a cannulated suture  110  forming a loop  120 , such that the cannulated suture  110  has a tubular wall defining an opening  112  at an end of the cannulated suture  110 , in which the opening  112  provides communication with a cannulated interior, and the loop  120  is defined by a segment  114  of the suture passed through the opening  112  into the cannulated interior and passed through a void  116  in the tubular wall in a finger trap arrangement, similar to a noose construction. It should be noted that there is no knot, but like a noose, the suture  110  is allowed to slide thought the cannulation of section  114 , such that the a distal end  138  passes through an opening  112  at the opposed (proximal) end, thus allowing the loop  120  diameter to be reduced. 
         [0026]    A suture anchor  130  is integrated with the cannulated suture  110 , via weaving or mesh construction to interleave, or “zig zag” around the suture  110  and is responsive to compress upon tightening of the loop  120 , shown further in  FIG. 3  below. The suture anchor  130  is adapted for fixation at a surgical site, and includes “all suture” construction, meaning that the suture anchor  130  itself is formed of resilient suture material. 
         [0027]    A fixation member  140  takes the form of a pledget or Endobutton® having a planer engagement surface  142  and a plurality of apertures  144 , such that the loop  120  engages the apertures  144  by passing the suture  110  therethrough for drawing the engagement surface  142  toward the suture anchor  130  via tightening of the loop  120 , as shown by arrows  132 , such that surgical attachment is provided for tissue disposed or compressed between the engagement surface  142  and the anchor  130 . The fixation member  140  may be a deformable anchor  100  as in  FIG. 1 , or may exhibit a more rigid construction. The distal end  138  of the cannulated suture is passed between the interior void and an exterior region outside the cannulated suture  110  for passing through the apertures  144  to form a cinch end  138 ′. 
         [0028]      FIG. 5  shows a cutaway view of a knotless suture and anchor assembly  101  following surgical insertion. Referring to  FIGS. 4 and 5 , in the configuration shown, the knotless suture anchor  101  is such that the tubular wall includes a tubular woven outer surface  118  around the cannulated interior defining an interior void. The suture anchor  130  is a non-rigid elongated member having alternate folds  134  and which is adapted to deform along the folds  134  for increasing a diameter of the elongated member for frictional engagement with a bone tunnel  150 . In a particular configuration, the elongated member (suture anchor  130 ) is woven into the tubular wall of the suture  110 , and is responsive to tightening of the cannulated suture  110  via the cinch end  138 ′ for drawing the alternate folds  134  together. The suture anchor  130  may be an all suture anchor comprising suture material, such that the suture anchor  130  and the cannulated suture  110  are comprised of the same material. The suture anchor  130  may also be any suitable resilient or textile material. 
         [0029]    The disclosed non-rigid knotless suture anchor assembly  101  is employed in a method of securing tissue  160  to other skeletal or connective members such as bone  162 . The distal end  138  of a cannulated suture  110  is passed through the plurality of apertures  144  in the fixation member  140 , such that the fixation member  140  has a planer surface  142 , and the cannulated suture  110  has a tubular wall defining an opening at distal and proximate ends of the suture  110  and an interior void defined by the cannulated interior of the suture  110 . The suture anchor  130  is integrated into the tubular wall  118  of the suture, such that the suture anchor  130  is adapted for fixation at a surgical site  170 . The distal end  138  forms a loop  120  in the cannulated suture  110 , via the opening  112  that provides communication with the cannulated interior, in which the loop  120  is defined by passing the suture  110  through the opening  112  into the cannulated interior and passed through a void  116  in the tubular wall  118 . The distal end  138  of the suture is passed through at least one of the apertures  144  in the fixation member  140  and adjacent to the suture  110  passing through the same aperture  144 . Insertion of the surgical anchor  130  causes it to compress via the alternate folds  134  upon pulling on the distal end  138  acting as a cinch for drawing the engagement surface  142  toward the suture anchor  130  via tightening of the loop  120 , such that surgical attachment is provided for the tissue  160  disposed between the engagement surface  142  and the bone  162 . 
         [0030]      FIG. 6  shows the integration of the cannulated suture and the suture anchor. Referring to  FIGS. 4-6 , the suture anchor  130  may engage the cannulated suture in a variety of ways for expanding the suture anchor  130  upon tightening of the loop  120  via the distal end  138 . In the example of  FIG. 3 , the cannulated suture  110  passes through apertures  131  in the suture anchor  130 . Upon tightening of the loop  120 , drawing the cannulated suture  110  closed, the suture anchor  130  is drawn along the folds  134  for expanding in a bone tunnel  150  or other installation void. 
         [0031]    In the configurations above, a deformable section (shown by the flexible section  125  and the folds  134  in the suture anchor  130 ) effectively provides a suture anchor with varying dimensions of length and width such that they may be passed through a suture aperture such as a bone tunnel for insertion, and achieve an alternate dimension for fixation. Depending on the “undeformed” or “at rest” state of the deformable suture anchor, the state of deformation may provide for insertion or fixation. Generally, the insertion state is a temporary compression or expansion which allows passage through an aperture, followed by fixation which causes the suture anchor to achieve a dimension preventing passage through the aperture. In colloquial terms, the suture anchor may be “squeezed” or “squished” through a hole, or inserted through and then “squished” or “squeezed” to enlarge the anchor against passage. 
         [0032]      FIGS. 7A and 7B  show respective undeformed and deformed (compressed) suture anchors of the configuration of  FIG. 1-3B . Referring to  FIGS. 1-3 ,  7 A and  7 B, the body  102  of the suture anchor  101  defines a first dimension  701 - 1  in an unfolded, or uncompressed state. In  FIG. 7B , the anchor  101  is folded along the deformable section  125  at the fold line  132 . The folded anchor has a second dimension  701 - 2 , which allows the anchor  101  to pass through a bone tunnel  150  or other surgical aperture. Following insertion, the anchor  101  is allowed to resume an undeformed state  701 - 1 , which prevents passage back though the aperture due to a “T” formation with the suture  121 . 
         [0033]    The suture anchor of  FIGS. 7A and 7B  therefore includes a deformable section  125 , the deformable section  125  varying a dimension  701 - 1 ,  701 - 2  of the suture anchor  101  for restraining the suture anchor  101  against a surgical aperture such as a bone tunnel  160 . The surgical anchor  101  includes at least one aperture  111 , or suture passage ( 2  shown), such that the suture passage  111  permits passage of the  121  suture through the anchor and into the surgical aperture. The suture anchor  100  has a first dimension allowing passage through the surgical aperture, and a second dimension restricting passage through the surgical aperture, the first  701 - 1  and second  701 - 2  dimensions based on the deformable section  125  (either the first or second dimension may be the smaller of the two for permitting passage). 
         [0034]    The deformable section  125  is responsive to external forces for modifying a cross section width, such as from an insertion tool or pulling on the suture  121  via the crossmember  120 , in which the deformation permits passage through the surgical aperture and subsequent expansion for preventing passage through the surgical aperture. In the example of  FIGS. 1-3 ,  7 A and  7 B, the deformable section  125  defines a fold  132  along a length or width of the suture anchor, such that the deformable suture anchor  101  is adapted for passage through the surgical aperture when folded as in  FIG. 7B . The deformable section  125  is therefore adapted to unfold following passage through the surgical aperture, such that the unfolded deformable section  125  defines an elongated suture anchor  100  having body  102  for restraining the suture anchor against the surgical aperture. 
         [0035]    The suture anchor  100  therefore includes at least one crossmember  120  between the surgical apertures  110 , such that the crossmember is adapted for engagement with a suture loop  142  from a suture  121  passed through at least two of the apertures  100 . The undeformed anchor  100 , having body  102 , is elongated and the deformed anchor folds substantially at a midsection or fold  132  ( FIG. 7B ), and returns to an undeformed shape ( FIG. 7A ) disposing the elongated side of the anchor normal to an axis of the skeletal aperture or bone tunnel  160 . 
         [0036]      FIGS. 8A-8B  show respective undeformed and deformed (compressed) configurations of  FIGS. 4-6 . Referring to  FIGS. 4-6 ,  8 A and  8 B, a knotless anchor  101  is shown that forms a suture loop  123  by passing the suture back through a mesh-constructed cannulated interior of itself and back out through a gap or aperture in the mesh. An elongated anchor structure  130  alternates folds  134  around the suture loop  123 , such that the suture  118  passes through holes  131  or apertures in the anchor  130 , which may also be a mesh construction. Upon tightening of the loop  123 , the folds  134  are pulled together, causing the anchor to contract from a first dimension (length)  801 - 1  to a second dimension  801 - 2 , and at the same time expand in width as the suture loop is closed, or tightened by drawing the suture  110  in the direction of arrow  802 . The mesh section  114  may also expand, contributing to the holding force of the deformed, or compressed anchor  130 . 
         [0037]    In the examples shown, the knotless suture anchor  101  is a non-rigid elongated member having alternate folds  134  and adapted to deform along the folds  134  for increasing a diameter of the elongated member (such as anchor  130 ) for frictional engagement with a bone tunnel  160 , securing the suture loop and thereby preventing passage of the suture via pulling through the bone tunnel  160 . In the example shown, the deformable section may be a mesh section defining a portion of the cannulated suture, such that passing through the gap in the cannulated suture forms the loop  123  responsive to closing from tightening the cannulated suture (arrow  802 ) for closing the loop  123  and compressing the mesh for deforming the suture anchor  130 , shown as compressed dimension  801 - 2 . The suture anchor is adapted for engagement with a fixation member  140  having an engagement surface  142  and a plurality of apertures  144 , in which the loop  123  engages the apertures for drawing the engagement surface  142  toward the suture anchor  130  via tightening  802  of the loop  123  and providing surgical attachment for tissue disposed between the engagement surface  142  and the suture anchor. The fixation member may be a resilient or textile fixation member  100  as disclosed above, or may be a rigid construction. 
         [0038]    While the disclosed configurations have been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention, but that various configurations will include all embodiments falling within the scope of the appended claims.