Abstract:
A suture system has a plurality of barbed sutures each with a plurality of barbs and a body connector that connects said plurality of barbed sutures. The sutures can move relative to the body connector. The body connector can retain tissue.

Description:
CLAIM TO PRIORITY 
     This application is a continuation of U.S. application Ser. No. 12/119,749, filed May 13, 2008, now pending; which is a divisional of U.S. application Ser. No. 10/914,755, filed Aug. 9, 2004, now U.S. Pat. No. 7,371,253, issued May 13, 2008; which is a divisional of U.S. application Ser. No. 10/216,516, filed Aug. 9, 2002, now U.S. Pat. No. 6,773,450, issued Aug. 10, 2004. All of the above claimed priority applications are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to a device and method for anchoring tissue within a body and, more particularly, to a suture anchor for use in surgical procedures requiring attachment of tissue, such as ligaments, tendons and the like, to other, preferably harder or more fibrous, tissue, such as a bone surface. 
     Suture anchors are used in surgical procedures wherein it is necessary for a surgeon to attach tissue to the surface of bone, for example, during joint reconstruction and ligament repair or replacement. Suture anchors generally comprise an anchor portion for fixed attachment to the bone, and a suture portion extending from the anchor portion used to connect the tissue to the bone. The anchor portion is often a generally cylindrical body having a sharp pointed end. An impact tool is typically used for driving the pointed end of the anchor into the bone. The outer surface of the anchor portion may be barbed or serrated to prevent the suture anchor from being withdrawn from the bone. The outer surface of the anchor portion could also be threaded and a driver, turned by a conventional drill, used to seat the threaded anchor portion into the bone. The anchor portion may also be fitted into a hole formed in the bone. 
     With the anchor portion securely in the bone, the suture portion is used for securing the tissue to the bone. The procedure typically involves passing a needle with the suture attached through the tissue. The tissue is advanced along the suture and tension is applied to the suture to draw the tissue tightly against the bone. The needle is removed and the tissue is secured against the bone by knotting the ends of the suture extending from the tissue. The knot is brought down to the surface of the tissue and tightened sufficiently to secure the tissue and bone in close approximation to promote reattachment and healing. A sliding retainer is sometimes used with the suture to pin the tissue against the bone. 
     There are other conventional suture anchors for attaching tissue to bone. For example, the anchor portion could take other forms including a staple which is driven into the bone surface with the suture positioned between the staple legs and the staple web fixing the suture to the bone surface. Also, a pair of closely-spaced holes can be drilled in the bone for passing the suture into one hole and out the other. However, these procedures are often difficult to perform, particularly in areas with limited access, such as deep wounds. 
     Further, conventional methods for approximating tissue to bone using a suture are difficult and inefficient because the procedure requires manipulation of the suture for securing the tissue in place. This is a time-consuming part of most surgical procedures, particularly in microsurgery and endoscopic surgery where there is insufficient space to properly manipulate the suture. 
     For the foregoing reasons, there is a need for an improved suture anchor for use in surgical procedures. The new suture anchor should eliminate the need for tying the suture to hold the tissue against the bone or other tissue surface. The method for using the suture anchor in surgical applications should allow a surgeon to approximate tissue to the bone or tissue surface in an efficient manner. A particularly useful new suture anchor would be used in surgical applications where space is limited such as microsurgery, endoscopic surgery or arthroscopic surgery. 
     SUMMARY OF THE INVENTION 
     According to the present invention, a suture anchor is provided for approximating tissue to bone or other tissue. The suture comprises an anchor member adapted to fixedly engage the bone for securing the anchor member relative to the bone. A plurality of sutures are mounted to the proximal end of the anchor member so that the sutures extend outwardly from the anchor member. Each suture has a sharp pointed distal end for penetrating the tissue and a plurality of barbs extending from the periphery of the body. The barbs permit movement of the sutures through the tissue in a direction of movement of the pointed end and prevent movement of the sutures relative to the tissue in a direction opposite the direction of movement of the pointed end. 
     Also according to the present invention, a method is provided for approximating tissue to a bone or other tissue to allow reapproximation and healing of the tissue and bone in vivo. The method uses a suture anchor including an anchor member adapted to be fixedly mounted to the bone and a plurality of sutures extending from the anchor member. The method comprises the steps of providing on each suture a sharp pointed distal end for penetrating the tissue and a plurality of barbs extending from the periphery of the body. The barbs permit movement of the sutures through the tissue in a direction of movement of the pointed end and prevent movement of the sutures relative to the tissue in a direction opposite the direction of movement of the pointed end. The anchor member is secured in the bone such that the sutures extend from the bone surface and a pointed end of a first suture is inserted into the tissue. The end of the first suture is pushed through the tissue along a curvilinear path in a direction away from the bone until the point at the end of the first suture extends out of the tissue at an exit point in the periphery of the tissue longitudinally spaced from the point of insertion. The pointed end of the first suture is gripped and pulled out of the tissue for drawing the first suture through the tissue while approximating the tissue adjacent the bone along the suture and leaving a length of the first suture in the tissue. The pointed end of the first suture is then inserted into the periphery of the tissue adjacent the exit point and pushed through the tissue along a curvilinear path in the direction away from the bone until the pointed end of the first suture extends out of the tissue at an exit point in the periphery of the tissue longitudinally spaced from the previous insertion point. The pointed end of the first suture is gripped and pulled out of the tissue for drawing the first suture through the tissue leaving a length of the first portion of the suture in the tissue. These steps are repeated with the first suture for advancing longitudinally along the tissue in the direction away from the bone. A second suture is then introduced into the tissue and the previous steps repeated so that the exit and entry points of the second suture are adjacent the corresponding exit and entry points of the first suture and the path of the second suture substantially mirrors the path of the first suture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, reference should now be had to the embodiments shown in the accompanying drawings and described below. In the drawings: 
         FIG. 1  is a perspective view of an embodiment of a suture anchor according to the present invention; 
         FIG. 2  is a perspective view of another embodiment of a suture anchor including a plurality of barbed sutures according to the present invention; 
         FIG. 3  is a side elevation view of an ankle with a portion of the outer layer of tissue cut-away to schematically show a torn Achilles tendon; 
         FIGS. 4-6  are schematic views of an embodiment of a method according to the present invention for reattaching the Achilles tendon to bone; 
         FIGS. 7-10  are perspective views of a method for joining two ends of a severed tendon according to the present invention; 
         FIGS. 11-13  are perspective, side and top plan views, respectively, of the suture pattern generated by the method shown in  FIGS. 7-10 ; 
         FIGS. 14-17  are perspective views of another method for joining two ends of a severed tendon according to the present invention; 
         FIGS. 18 and 19  are perspective and side elevation views, respectively, of the suture pattern generated by the method shown in  FIGS. 14-17 ; and 
         FIGS. 20 and 21  are side and rear elevation views, respectively, of the ankle shown in  FIG. 3  with the torn Achilles tendon reattached to the bone using the suture anchor and method shown in  FIGS. 7-13  according to the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As used herein, the term “tissue” includes tendons, ligaments, cartilage, muscle, skin, organs, and other soft tissue. The term “bone” includes bone, cartilage, tendon, ligament, fascia, and other connective or fibrous tissue suitable for anchor for a suture. 
     Certain other terminology is used herein for convenience only and is not to be taken as a limitation on the invention. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” merely describe the configuration shown in the FIGs. It is understood that the components may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise. 
     Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout the several views, there is shown in  FIG. 1  a suture anchor for use according to the present invention and generally designated at  30 . The suture anchor  30  includes an anchor portion  32  and a suture portion  34 . The anchor portion  32  comprises an elongated body  36  having a distal pointed tip  38  which serves as a leading end of the suture anchor  30  when the suture anchor is inserted into bone. A blind bore  40 , or opening, is formed at the proximal end  41  of the anchor portion  32 . A crossbar  42  integral with the anchor body  36  spans the opening  40  for threadably receiving the suture portion  34  at the proximal end of the anchor portion  32 . 
     The anchor portion  32  is shown as having a circular cross-section, although other cross-sectional shapes could be utilized without departing from the present invention. As shown in  FIG. 1 , ridges  44 , or barbs, may be formed on the outer surface of the anchor portion  32  which allow movement of the anchor portion  32  through bone in one direction but which resist the withdrawal of the anchor portion  32  after the anchor portion has been implanted in the bone. 
     As described above, the anchor portion  32  is driven into the bone surface, pointed tip  38  first, by impact against the proximal end  41 , or by turning as when the anchor portion  32  is threaded (not shown). The anchor portion  32  can also be disposed into a hole bored in the bone, in which case insertion can be accomplished with direct pressure or gentle tapping on the proximal end  41  of the anchor portion  32 . The ridges  44  on the surface of the anchor body  36  grasp the bone rendering the anchor portion  32  substantially irremovable from the bone. Tension on the suture portion  34  enhances this effect. 
     The suture portion  34  of the suture anchor  30  has an elongated body  46  and a plurality of barbs  48  disposed along the length of the body  46 . First and second ends  50 ,  52  of the suture body  46  terminate in points  54 ,  56  for penetrating tissue. The body  46  of the suture portion  34  is, in one embodiment, circular in cross section. Suitable diameters for the body  46  range from about 0.001 mm to about 5.0 mm. The body  46  of the suture portion  34  could also have a non-circular cross-sectional shape which would increase the surface area of the body  46  and facilitate the formation of multiple barbs  48 . The length of the suture portion  34  can vary depending on several factors, including the desired surgical application, the type of tissue to be approximated to the bone, the location of the bone, and the like. A suture portion  34  of proper length is selected for achieving suitable results in a particular application. 
     The plurality of barbs  48  is axially-spaced along the body  46  of the suture portion  34 . The barbs  48  are oriented in one direction facing toward the first end  50  of the suture body  46  for a first portion  58  of the length of the suture portion  34  and in an opposite direction facing the second end  52  of the suture body  46  for a second portion  60  of the suture portion  34 . The point on the suture body  46  where the barbs  48  change direction is preferably positioned adjacent the crossbar  42  at the proximal end of the anchor body  36 . The barbs  48  are yieldable toward the body  46 . The barbs  48  on each portion  58 ,  60  of the suture body  46  are oriented so as to allow movement of the suture portion  34  through the tissue in one direction along with the corresponding end  50 ,  52  of the suture portion  34 . The barbs  48  are generally rigid in an opposite direction to prevent the suture body  46  from moving in the tissue in the opposite direction. 
     The barbs  48  can be arranged in any suitable pattern, for example, in a helical pattern as shown in  FIG. 1 . The number, configuration, spacing and surface area of the barbs  48  can vary depending upon the tissue in which the suture portion  34  is used, and depending on the composition and geometry of the suture body  46 . The proportions of the barbs  48  may remain relatively constant while the overall length and spacing of the barbs  48  are determined by the tissue being approximated to the bone. For example, if the suture portion  34  is intended to be used in tendon, the barbs  48  can be made relatively short and more rigid to facilitate entry into this rather firm, fibrous tissue. If the suture portion  34  is intended for use in soft tissue, such as fat, the barbs  48  can be made longer and spaced farther apart to increase the holding ability in the soft tissue. Moreover, the ratio of the number of barbs  48  on the first portion  58  of the suture body  46  to the number of barbs  48  on the second portion  60 , and the lengths of each portion  58 ,  60 , can vary depending on the surgical application and needs. 
     The surface area of the barbs  48  can also vary. For example, fuller-tipped barbs  48  can be made of varying sizes designed for specific surgical applications. For joining fat and relatively soft tissues, larger barbs  48  are desired, whereas smaller barbs  48  are more suited for collagen-dense tissues. There are also situations where a combination of large and small barbs  48  within the same structure will be beneficial such as when the suture portion  34  is used in the repair of tissue with differing layered structures. Use of the combination of large and small barbs  48  with the same suture portion  34  wherein barb  48  sizes are customized for each tissue layer will ensure maximum anchoring properties. 
     The barbs  48  may be formed on the surface of the suture body  46  according to any suitable method, including cutting, molding, and the like. The preferred method is cutting with acute angular cuts directly into the suture body  46  with the cut portions pushed outwardly and separated from the body  46 . The depth of the barbs  48  formed in the suture body  46  depends on the diameter of the suture material and the depth of cut. Embodiments of a suitable cutting device for cutting a plurality of axially spaced barbs  48  on the exterior of suture filaments are shown and described in U.S. patent application Ser. No. 09/943,733, entitled “Method Of Forming Barbs On A Suture And Apparatus For Performing Same”, which was filed on Aug. 31, 2001, the contents of which are hereby incorporated by reference. This cutting device utilizes a cutting bed, a cutting bed vise, a cutting template, and a blade assembly to perform the cutting. When operated, the cutting device has the ability to produce a plurality of axially spaced barbs  48  in the same or random configuration and at different angles in relation to each other. Various other suitable methods of cutting the barbs  48  have been proposed including the use of a laser. The barbs  48  could also be cut manually. However, manually cutting the barbs  48  is labor intensive, decreases consistency, and is not cost effective. The suture portion  34  could also be formed by injection molding, extrusion, stamping and the like. 
     Barbed sutures suitable for use according to the methods of the present invention are described in U.S. Pat. No. 5,342,376, entitled “Inserting Device for a Barbed Tissue Connector”, U.S. Pat. No. 6,241,747, entitled “Barbed Bodily Tissue Connector”, and U.S. Pat. No. 5,931,855. The contents of U.S. Pat. No. 5,342,376, U.S. Pat. No. 5,931,855 and U.S. Pat. No. 6,241,747 are hereby incorporated by reference. 
     The suture portion  34  is attached to the proximal end of the anchor portion  32 . As seen in  FIG. 1 , the suture portion  34  is threaded around the crossbar  42  on the anchor body  36 . It is understood that the suture portion  34  may be attached to the anchor portion  32  in a number of ways, including inserting the end of the suture body  46  into the bore  40  formed in the proximal end of the anchor body  36  and securing the suture body  46  in place with a set screw, rivet, or the like, or, wherein the material of the anchor portion  32  is metal, by swaging or crimping. The anchor portion  32  and suture portion  34  could also be formed in one piece in the manufacturing process. However, the preferred attachment of the suture portion  34  is as shown in  FIG. 1  since this arrangement allows a simple, secure threading of a double-ended suture portion  34  during manufacture or prior to use. Moreover, as seen in  FIG. 2 , the user may selectively attach several suture portions  34  to the anchor portion  32  depending upon the surgical application. 
     Suitable material for the body  46  of the suture portion  34  is available in a wide variety of monofilament suture material. The particular suture material chosen depends on strength and flexibility requirements. In one embodiment, the material for the suture body  46  is flexible and substantially nonresilient so that the shape of an inserted suture portion  34  will be determined by the path of insertion and the surrounding tissue. In some applications, however, it may be desirable for at least a portion of the suture body  46  to have sufficient dimensional stability to assume a substantially rigid configuration during use and sufficient resiliency to return to a predetermined position after deflection therefrom. The portions of the ends  50 ,  52  of the suture body  46  adjacent the points  54 ,  56  may be formed of a material sufficiently stiff to enable the points  54 ,  56  to penetrate tissue in which the suture portion  34  is used when a substantially axial force is applied to the body  46 . Variations in surface texture of the suture body  46  can impart different interaction characteristics with the tissue. 
     The ends  50 ,  52  of the suture portion  34  may be straight ( FIG. 1 ) or curved ( FIG. 2 ). In one embodiment, the ends  50 ,  52  of the suture portion  34  may be surgical needles secured at each end of the suture portion  34  so that the body  46  extends between the shank ends of the two needles. The needles are preferably constructed of stainless steel or other surgical-grade metal alloy. The needles may be secured to the suture body  46  by means of adhesives, crimping, swaging, or the like, or the joint may be formed by heat shrinkable tubing. A detachable connection may also be employed such that the needles may be removed from the suture body  46  by a sharp tug or pull or by cutting. The length of the needles is selected to serve the type of tissue being repaired so that the needles can be completely removed leaving the suture body  46  in the desired position within the tissue. 
     The suture anchor  30  of the present invention can be formed of a bioabsorbable material which allows the suture anchor  30  to be absorbed by the body over time. Bioabsorbable material is particularly useful in arthroscopic surgery and procedures. Many compositions useful as bioabsorbable materials can be used to make the suture anchor  30 . Generally, bioabsorbable materials are thermoplastic polymers. Selection of the particular material is determined by the desired absorption or degradation time period which depends upon the anticipated healing time for the subject of the procedure. Biodegradable polymers and co-polymers range in degradation time from about one month to over twenty-four months. They include, but are not limited to, polydioxanone, polylactide, polyglycolide, polycaprolactone, and copolymers thereof. Other copolymers with trimethylene carbonate can also be used. Examples are PDS II (polydioxanone), Maxon (copolymer of 67% glycolide and 33% trimethylene carbonate), and Monocryl (copolymer of 75% glycolide and 25% caprolactone). Germicides can also be incorporated into the suture anchor  30  to provide long lasting germicidal properties. 
     Alternatively, either the anchor portion  32  or the suture portion  34  of the suture anchor  30  can be formed from non-absorbable material such as, for example, nylon, polyethylene terephthalate (polyester), polypropylene, and expanded polytetrafluoroethylene (ePTFE). The suture body  46  can also be formed of metal (e.g. steel), metal alloys, or the like. Titanium is a preferred material when the anchor portion  32  is to remain permanently in the bone. A suitable anchor portion  32  for use according to the present invention is available from Mitek Products of Norwood, Mass. Alternatively, the anchor portion  32  can also be a rigid barbed structure made from thick monofilament suture material with barbs suitable for anchoring in bone. 
     In use in an orthopedic surgical procedure, the anchor portion  32  of the suture anchor  30  of the present invention is inserted into bone. Once the anchor portion  32  is fixed in place, the suture portion  34  extends outwardly from the anchor portion  32  and the bone for surgical suturing to tissue to be approximated to the bone. The tissue is brought into position over the suture anchor  30  site. The point  54  at one end  50  of the suture portion  34  is inserted into the tissue such that the point  54  pierces the tissue and the barbs  48  on the portion  58  of the suture body  46  corresponding to the one end  50  yield toward the body  46  to facilitate movement of the suture body as it is drawn through the tissue in the direction of insertion. The point  56  at the other end  52  of the suture portion  34  is also inserted into the tissue and advanced through the tissue in like manner. The tissue is then advanced along the suture portions  58 ,  60  within the tissue to close the gap between the tissue and the bone. The barbs  48  of the suture body  46  grasp the surrounding tissue and maintain the tissue in position adjacent to the bone during healing. The leading ends  50 ,  52  of the suture body  46  protruding from the tissue are then cut and discarded. 
     According to the present invention, a surgical procedure using the suture anchor  30  is provided for approximating a torn Achilles tendon to bone for reattachment and healing. It is understood that the applicants do not intend to limit the suture anchor  30  and method of the present invention to only the reattachment of the Achilles tendon. 
     Referring to  FIG. 3 , a human foot  70  is shown with a portion of the outer layer  72  of skin and tissue cutaway to schematically show the Achilles tendon  74  torn away from the heel bone  76 . In this embodiment of the present invention, the user, such as a surgeon, selects a suture anchor  30  ( FIG. 4 ) having a suture portion  34  of sufficient length and having curved ends  50 ,  52  which, in one embodiment, as noted above may be surgical needles. As seen in  FIG. 4 , the surgeon begins by inserting the suture anchor  30  into the heel bone  76 . The first and second portions  58 ,  60  of the elongated suture portion  34  extend from the anchor portion  32 . Next the surgeon inserts the first end  50  ( FIG. 5 ), or surgical needle, into the free end of the Achilles tendon  74  and pushes the needle  50  through the tendon  74  along a selected curvilinear path until the point  54  at the first end of the needle  50  extends from an exit point  78  at the periphery of the tendon  74  longitudinally spaced from the end of the tendon. The surgeon grips the needle  50  and pulls the needle out of the tendon  74  for drawing the first portion  58  of the suture body  46  through the tendon  74  leaving a length of the first portion  58  of the suture body  46  in the tendon  74  between the end of the tendon and the exit point  78 , as seen in  FIG. 6 . These steps are repeated with the second portion  60  of the suture body  46  beginning with insertion into the end of the tendon  74 . 
     Methods according to the present invention useful in binding together partially or completely severed tendons, or other internal tissue repairs requiring considerable tensile strength, are suitable for use in attaching tissue to bone. One such method for joining two ends  82 ,  84  of a tendon  80  is shown in  FIGS. 7-10 . Referring to  FIG. 7 , the surgeon begins by inserting a first end  92  of a two-way barbed suture  90 , which may comprise a straight or curved surgical needle, into one end  82  of the tendon  80  and pushing the needle  92  through the tendon  80  along a selected curvilinear path until the point  94  of the needle  92  extends from an exit point  96  in the periphery of the tendon  80  longitudinally spaced from the one end  82  of the tendon  80 . The first needle  92  is gripped and pulled out of the tendon  80  for drawing a first portion  98  of the suture  90  through the tendon  80  leaving a length of the first portion  98  of the suture  90  in the tendon end  82  between the end of the tendon  80  and the exit point  96 . As seen in  FIG. 7 , these steps are repeated with a second portion  100  of the suture  90  at the other end  84  of the tendon  80 , wherein a second end  93  of the suture  90  is inserted into the tendon end  84  and advanced along a selected curvilinear path to an exit point  97  longitudinally spaced from the end  84  of the tendon  80 . The second end  93  of the suture  90  projecting from the exit point  97  is gripped and pulled out of the tendon  80  for drawing the second portion  100  of the suture  90  through the tendon  80  and leaving a length of the second portion  100  of the suture  90  in the tendon end  84  ( FIG. 8 ). 
     Referring now to  FIG. 8 , a second suture  90   a  is introduced into the ends  82 ,  84  of the tendon  80 . The first needle  92   a  of the second suture  90   a  is inserted into the one end  82  of the tendon  80  and pushed through the tendon along a selected curvilinear path until the needle  92   a  extends from an exit point  96   a  in the periphery of the tendon  82  substantially co-located with the first exit point  96  of the first portion  98  of the first suture  90 . These steps are repeated with the second portion  100   a  of the second suture  90   a  at the other end  84  of the tendon  80  such that the exit point  97   a  in the periphery of the end of the tendon  84  is substantially co-located with the first exit point  97  of the second portion  100  of the first suture  90 . The needles  92   a ,  93   a  of the second suture  90   a  are pulled out of the tendon  80  for drawing the first and second portions  98   a ,  100   a , respectively, of the second suture  90   a  through the tendon  80  leaving a length of the second suture  90   a  in the tendon  80  between the exit points  96   a ,  97   a.    
     As shown in  FIG. 9 , the surgeon reinserts the first needle  92  of the first suture  90  into the periphery of the one end  82  of the tendon  80  at an entry point  102  immediately adjacent the exit point  96  and pushes the needle  92  along a selected curvilinear path until the point  94  of the needle  92  exits the same side of the tendon  82  at an exit point  104  that is longitudinally spaced from the entry point  102 . It is understood that the surgeon could use the exit point  96  as the entry point  102  for the needle  92  if desired. The surgeon pulls the needle  92  out of the tendon  82  for drawing the first portion  98  of the suture  90  through the tendon  82 . The surgeon may then reinsert the needle  92  into the tendon  82  at an entry point (not shown) immediately adjacent the exit point  104  and push the needle  92  along a selected curvilinear path and out of the same side of the tendon  82  at an exit point (not shown) longitudinally spaced from the previous entry point. It is understood that the surgeon makes as many passes as deemed necessary in a “wave-like” pattern for holding the end  82  of the tendon, or as the length or thickness of the tendon  82  allows, and removes the remaining length of the first portion  98  of the suture  90 . 
     The surgeon repeats the steps described above with the first portion  98   a  of the second suture  90   a  ( FIG. 10 ) by reinserting the needle  92   a  into the tendon  82  at an entry point  102   a  adjacent the exit point  96   a , crossing over the first portion  98  of the first suture  90 , and pushing the needle  92   a  along a selected curvilinear path until the needle  92   a  emerges from an exit point  104   a  in the periphery of the tendon  82  substantially co-located with the second exit point  104  of the first portion  98  of the first suture  90 . In this manner, the surgeon advances longitudinally along the end  82  of the tendon  80  with the first portion  98   a  of the second suture  90   a  in a “wave-like” pattern which generally mirrors that of the first portion  98  of the first suture  90 . 
     The previous steps are repeated at the other end  84  of the tendon  80  with the second portions  100 ,  100   a  of the first suture  90  and second suture  90   a . The pattern of the second portions  100 ,  100   a  of the sutures  90 ,  90   a  in the second end  84  of the tendon  80  generally mirrors that of the first portions  98 ,  98   a  of the sutures in the first end  82  of the tendon  80 . Thus, the exit points and entry points of the first and second sutures  90 ,  90   a  are substantially co-located. 
     The ends  82 ,  84  of the tendon  80  are brought together by pushing the tendon ends along the sutures while maintaining tension on the free ends  92 ,  92   a ,  93 ,  93   a  of the sutures  90 ,  90   a . The barbs  48  maintain the sutures  90 ,  90   a  in place and resist movement of the tendon ends  82 ,  84  away from this position. The needles along with remaining lengths of the suture portions  98 ,  98   a ,  100 ,  100   a  are cut and discarded. 
       FIGS. 11-13  show the suture pattern resulting from use of the above-described method of the present invention. It is understood that we do not intend to limit ourselves to the depth or length of the suture paths shown in the FIGs. as the amount of tissue grasped by each pass, which is related to the depth of the suture path into the tissue and the length of the pass from entry point to exit point, may be determined by the surgeon based on a number of factors including the tissue to be joined. 
     Another method according to the present invention for joining two ends  82 ,  84  of a tendon  80  which is suitable for use in attaching tissue to bone is shown in  FIGS. 14-17 . Referring to  FIG. 14 , the surgeon begins by inserting the first end  92  of a two-way barbed suture  90 , which may comprise a straight or curved surgical needle, into one end  82  of the tendon  80  and pushing the needle  92  through the tendon  82  along a selected curvilinear path until the point  94  of the needle  92  extends from an exit point  96  in the periphery of the tendon  82  longitudinally spaced from the one end  82  of the tendon. The first needle  92  is gripped and pulled out of the tendon  82  for drawing the first portion  98  of the suture  90  through the tendon  80  leaving a length of the first portion  98  of the suture in the tendon  80  between the tendon end  82  and the exit point  96 . As seen in  FIG. 14 , these steps are repeated with the second portion  100  of the suture  90  at the other end  84  of the tendon  80 . That is, a second end  93  of the suture  90  is inserted into the tendon end  84  and advanced along a selected curvilinear path to an exit point  97  longitudinally spaced from the end  84  of the tendon  80 . The exit point  97  of the second needle  93  is on the opposite side of the tendon  80  from the first exit point  96  of the first portion  98  of the suture  90 . The second end  93  of the suture  90  projecting from the exit point  97  is gripped and pulled out of the tendon  80  for drawing the second portion  100  of the suture  90  through the tendon  80  and leaving a length of the second portion  100  of the suture  90  in the tendon end  84  ( FIG. 15 ). 
     Referring now to  FIG. 15 , a second suture  90   a  is introduced into the ends  82 ,  84  of the tendon  80 . The first needle  92   a  of the second suture  90   a  is inserted into the end  82  of the tendon  80  and pushed through the tendon along a selected curvilinear path until the needle  92   a  extends from an exit point  96   a  in the periphery of the tendon  82  substantially co-located with the first exit point  96  of the first portion  98  of the first suture  90 . These steps are repeated with the second portion  100   a  of the second suture  90   a  at the other end  84  of the tendon  80  such that the exit point  97   a  in the periphery of the end of the tendon  84  is substantially co-located with the first exit point  97  of the second portion  100  of the first suture  90 . The needles  92   a ,  93   a  of the second suture  90   a  are pulled out of the tendon  80  for drawing the first portion  98   a  and second portion  100   a  of the second suture  90   a  through the tendon  80  leaving a length of the second suture  90   a  in the tendon  80  between the exit points  96   a ,  97   a.    
     As shown in  FIG. 16 , the surgeon reinserts the second needle  92   a  into the periphery of the one end  82  of the tendon  80  at an entry point  102   a  immediately adjacent the exit point  96   a  and pushes the needle  92   a  along a selected curvilinear path until the point  94   a  of the needle  92   a  exits the opposite side of the tendon  82  at an exit point  104   a  that is longitudinally spaced from the entry point  102   a . It is understood that the surgeon could use the first exit point  96   a  as the entry point  102   a  for the needle  92   a  if desired. The surgeon pulls the needle  92   a  out of the tendon  82  for drawing the first portion  98   a  of the suture  90   a  through the tendon  82 . The surgeon may then reinsert the needle  92   a  into the tendon  82  at an entry point (not shown) immediately adjacent the exit point  104   a  and push the needle  92   a  along a selected curvilinear path and out of the opposite side of the tendon  82  at an exit point (not shown) longitudinally spaced from the previous entry point. It is understood that the surgeon makes as many passes in a “side-to-side” pattern as deemed necessary for holding the end  82  of the tendon  80 , or as the length or thickness of the tendon end  82  allows, and removes the remaining length of the first portion  98   a  of the second suture  90   a . With each pass, the longitudinal distance between the entry point and exit point decreases. The surgeon repeats these steps with the second portion  100   a  of the second suture  90   a  at the other  84  of the tendon  80 . The second end  93   a  of the suture  90   a  is inserted into the other end  84  of the tendon  80  at an entry point  106   a  immediately adjacent the first exit point  97   a  and advanced along a selected curvilinear path to an exit point  108   a  opposite and longitudinally spaced from the entry point  106   a . The second portion  100   a  of the second suture  90   a  is drawn through the tendon  80  leaving a length of the second portion  100   a  of the suture  90   a  in the tendon ( FIG. 17 ). 
     The surgeon repeats the steps described above with the first portion  98  and second portion  100  of the first suture  90  at the ends  82 ,  84  of the tendon  80 . As seen in  FIG. 17 , the needle  92  at the end of the first portion  98  is inserted into the tendon end  82  at an entry point  102  adjacent the exit point  96  and pushed along a selected curvilinear path until the needle  92  emerges from an exit point  104  in the periphery of the tendon  82  substantially co-located with the second exit point  104   a  of the first portion  98   a  of the second suture  90   a . In this manner, the surgeon advances longitudinally along the end  82  of the tendon  80  with the first portion  98  of the first suture  90  in a “side-to-side” pattern which generally mirrors that of the first portion  98   a  of the second suture  90   a . Similar steps are taken with the second portion  100  of the first suture  90  in the other end  84  of the tendon  80 . The pattern of the first suture  90  and second suture  90   a , as well as the respective first portions  98 ,  98   a  and second portions  100 ,  100   a  of the sutures  90 ,  90   a , generally mirror one another. The exit points and entry points of the sutures are substantially co-located. The ends  82 ,  84  of the tendon  80  are brought together by pushing the tendon ends along the sutures while maintaining tension on the free ends of the sutures  90 ,  90   a . The barbs  48  maintain the sutures  90 ,  90   a  in place and resist movement of the tendon ends  82 ,  84  away from this position. The needles, along with remaining lengths of the sutures, are cut and discarded.  FIGS. 18 and 19  show the suture pattern using the above-described method of the present invention. 
     It is understood that more sutures may be used in any of the methods of the present invention. The number of sutures used depends on the size, caliber, and length of the tendon to be repaired. Large tendons will require more than two sutures whereas one may suffice for very small tendons. Tendon repair with two sutures according to the present invention exhibits equivalent or better holding power than conventional techniques. Moreover, tendons repaired according to the methods of the present invention maintain their original configuration, profile, contour, and form better when subject to stretching forces. Other methods of tendon repair suitable for use according to the present invention are shown and described in U.S. patent application Ser. No. 09/896,455, entitled “Suture Method”, which was filed on Jun. 29, 2001, the contents of which are hereby incorporated by reference. 
       FIGS. 20 and 21  are two views of the Achilles tendon  74  reattached to the heel bone  76  to promote healing according to the present invention using the suture method shown in  FIGS. 7-13 . The tendon  74  and bone  76  will, over time, grow together. 
     The present invention provides a compact and easy to use suture anchor and method for reattaching tissue, such as tendons and ligaments, to bone or other connective tissue. The curvilinear placement paths of the suture portion, as contrasted with linear insertion, provide substantially increased biomechanical strength for approximating tissue and bone, or the ends of tendon. The barbed suture portion permits tissue to be approximated and held snug during suturing with less slippage of the suture in the wound. The barbs spread out the holding forces evenly thereby significantly reducing tissue distortion. The suture anchor is useful in endoscopic and arthroscopic procedures and microsurgery. Since knots do not have to be tied, arthroscopic knot tying instruments are unnecessary. If there is an accidental breakage of the barbed suture, the wound is minimally disturbed whereas, with conventional sutures, dehiscence would occur. 
     Although the present invention has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, it should be understood by those skilled in the art that we do not intend to limit the invention to the embodiments since various modifications, omissions and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. For example, the methods of the present invention can be used with a suture anchor alone as a two-way barbed suture. Accordingly, we intend to cover all such modifications, omissions, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims.