Abstract:
Apparatuses and methods are provided for arthroscopic rotator cuff repair incorporating a transhumeral bone tunnel. The apparatus comprises a number of components that can also be considered a repair system to include a drill guide, a marking hook, and a drill with a removable tip that serves as a bone anchor. In another aspect, the invention provides a suture especially adapted for securing both soft tissue and bone anchors that reduces forces transmitted to the anchors by secondary anchoring of the suture within the bone tunnel based on the geometry of the anchor. In additional aspects of the invention, the components of the drill guide assembly comprise a cannulated marking hook and a drill guide with multiple bores. In additional aspects of the invention, an implantable bone anchor is provided that is especially adapted for placement through a bone tunnel, and wherein the implantable anchor is collapsible to increase the effective size of the anchor for securing the anchor to the far side opening of the bone tunnel through which the anchor was placed. Methods of the invention include a method of arthroscopic repair of a rotator cuff, and methods of activating an implantable anchor.

Description:
FIELD OF THE INVENTION 
     The present invention relates to surgical devices and methods for repair of torn tissue, and more particularly, to an apparatus and method for repair of a damaged rotator cuff by transhumeral suture anchoring in an arthroscopic procedure. 
     BACKGROUND OF THE INVENTION 
     Rotator cuff injuries are a very common injury suffered by patents of all ages. A torn rotator cuff typically requires a surgical procedure to reattach the torn tendons to the bone of the humeral head. Rotator cuff injuries are particularly bothersome in that the torn tendons must be highly stabilized in order for healing to occur. 
     In recent years, the preferred solution to ensure proper healing of a rotator cuff is to increase the number of anchors used to secure the torn tissue to the bone. Although increasing the number of anchors used in the procedure can result in improved healing, there are also a number of drawbacks associated with the increased use of anchors, most notably, the cost of the procedure. 
     One known prior art surgical technique for repair of a rotator cuff is the use of a plurality of suture anchor screws that are placed in the head of the humerus bone. The sutures are then threaded through the anchor screws and are passed through the rotator cuff tissue and overlying musculature, resulting in a web of suture strands that are tied to one another thereby reattaching the rotator cuff to the humerus head. One particular disadvantage with this known type of rotator cuff repair is that the plurality of screws is secured within the cancellous bone mass beneath the near cortex of the head of the humerus. This bone mass in the humerus head is particularly susceptible to osteopenic degradation in which the bone density can significantly diminish, particularly in older patents. Accordingly, anchors placed in this degraded cancellous bone mass do not remain stationary, and some degree of pullout or loosening will occur, thereby preventing proper healing of the tendon tissue to the bone. 
     Two references that disclose apparatuses and methods of rotator cuff repair that do not locate the anchors within the cancellous bone mass of the humeral head are the U.S. Pat. Nos. 6,013,083 and 6,206,886 to Bennett. These references disclose a method wherein a bone tunnel is formed completely through the humeral head extending to the far cortex. An anchor is located at the far cortex within the bone tunnel and sutures are attached to the anchor and extend through the bone tunnel. More specifically, these references disclose an apparatus and method wherein a cannula is inserted through the skin substantially to the torn tissue. A drill guide is inserted in the cannula, a drill bit is inserted in the drill guide, and a hole is then drilled through the torn tissue and completely through the humeral head. The drill bit is removed and an inner cannula is passed through the drill guide until its distal end is engaged in the torn tissue or alternatively passed through the hole until its distal end is at the far end of the drilled hole. A soft tissue anchor having expandable wings at its distal end and sutures secured to an eyelet at its proximal end is releasably connected to the distal end of a tubular deployment tool with the free ends of the sutures extending through the deployment tool. The deployment tool is passed through the inner cannula and drilled hole until the expandable wings clear the far end of the hole a sufficient distance to allow the wings to expand to a diameter larger than the diameter of the drilled hole. The deployment tool, inner cannula, drill guide, and cannula are removed and tension is applied to the sutures to engage the expanded wings of the anchor on the exterior surface of the bone surrounding the drilled hole. A button is run down the sutures through the cannula and secured on the torn tissue by the sutures such that the torn tissue is secured to the bone and the sutures are anchored to the hard exterior surface of the bone by the expanded anchor. 
     It is also known within arthroscopic procedures to provide a drill guide in order to selectively drill a tunnel through bone in a precise, directed manner such that the bone tunnel can be used to pass sutures to an anchor located on the far end of the tunnel. Two known references that disclose drill guides for drilling tunnels in the tibia for replacement or repair of knee tendons include the U.S. Pat. Nos. 5,112,337 and 5,350,383. 
     Although the drill guides of these prior art references are well known for arthroscopic repair of knee tendons, these drill guides have been limited to use with the knee joint, and have not been used as drill guides for other joints. 
     With respect to repair of a torn rotator cuff, there is still a need to provide an apparatus and method in which the procedure conducted is minimally invasive, minimizes the amount of required hardware, yet is a reliable, repeatable procedure. There is also a need to provide such a procedure in which anchoring of the sutures is achieved by bypassing the cancellous bone mass on the humeral head, and taking advantage of the far cortex of the bone that has a higher density therefore providing a better means to anchor the sutures. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an apparatus and method for repair of torn rotator cuff tissue wherein sutures are anchored along the far cortex of the bone thereby bypassing the cancellous bone mass. 
     It is yet another object of the present invention to provide an apparatus and method in which the procedure can be conducted in a minimally invasive manner by minimizing the number of suture passes through the soft tissue, yet ensuring that the sutures are suitably anchored in both a far bone anchor point, as well as a near anchor point in the soft tissue surrounding the rotator cuff. 
     It is yet another object of the present invention to provide an apparatus and method in which a drill guide can be used to precisely locate bone tunnels to be drilled, and the drill guide is easily adaptable for use with patients of differing sizes. 
     It is yet another object of the present invention to generally simplify the surgical procedure of a repairing a torn rotator cuff repair in which not only is the amount of implanted hardware reduced, but also the procedure is simplified by minimizing the surgical tools required to conduct the procedure. 
     It is yet another object of the present invention to provide various suture constructions and suture anchor constructions that facilitate the apparatus and method of the invention. 
     The above objects and other objects of the invention not specifically articulated are accomplished by the present invention that includes an apparatus and method for repair of torn rotator cuffs. 
     In accordance with the apparatus of the present invention, a drill guide and drill are provided that are especially adapted for repair of a torn rotator cuff. The drill guide includes a marking hook that is especially adapted for the shape of the humeral head such that a bone/transosseous tunnel can be drilled completely through the humeral head. The drill of the present invention includes a drill bit tip that is used to drill a tunnel through the bone mass, and then serves as the suture anchor. The drill bit tip includes a transverse aperture that can be held by the marking hook, and the drill shaft is then removed from the drill bit tip. The drill bit tip is rotated to extend transversely across the opening formed on the far side of the bone tunnel, and then sutures are passed through the bone tunnel and are secured to the drill bit tip through the aperture of the drill bit tip. The surgeon may then choose the type of soft tissue anchor to be placed on the rotator cuff and musculature surroundings of the rotator cuff. The marking hook can be cannulated as by incorporation of an orifice extending through the marking hook, to thereby allow passage of sutures within the marking hook. After drilling across the humerus, sutures can be passed through the orifice of the marking hook. The suture can then either be passed into the opening of the drill tip or can be grasped by a device placed across the bone/transosseous tunnel. 
     Also in accordance with the present invention, the method of the present invention contemplates a cortical bone bridge in which two or more bone tunnels can be drilled through the humeral head, and then the sutures can be passed through the bone tunnels in the desired pattern for securing the torn rotator cuff tissue. 
     In yet another aspect of the present invention, a particularly advantageous self-anchoring suture is provided. This self-anchoring suture incorporates a dispersed pattern of protuberances or beads that can be passed in a specified direction through the bone tunnel but prevent pullout by force applied in the opposite direction. 
     An additional suture configuration provided to accommodate the transosseous aiming apparatus of the present invention is a suture construction having a mesh-like structure mounted to a conventional suture. The mesh structure is initially rolled tightly around the suture, and then unfurled after the suture ends have been deployed across the humerus and tied along the medial far cortex. The mesh could be a scaffold of any synthetic material or biologic material. The mesh construct could be rolled tightly around the conventional suture, contained in a sleeve, or rolled into place along the body of the conventional suture. The mesh can be provided in various lengths and widths, and would provide “canopy” coverage of the cuff tear. The interface of the canopy and the cuff tendon underneath could be imbued with biologic growth factors or other substances to promote healing. 
     Another far-cortical anchoring device that can be used with the aiming apparatus of the present invention is a compression fixation anchor that is formed as a cylinder with sutures placed through small holes formed near the distal end of the cylinder. The anchor body has longitudinally extending cuts or slits, and the anchor body is scored circumferentially to allow folding or collapsing of the device at its mid-portion. As the anchor collapses, it becomes much large in circumference. One method of advancing the anchor is to place a nitinol wire through the transosseous tunnel, and then advance the anchor down the nitinol wire in a cannulated fashion while retaining the suture ends. Once the anchor is in the glenohumeral space, tension is applied on the sutures, causing deployment of the wider mid-portion of the anchor. Another method of advancing the anchor is to employ an inserting device through the tunnel in which the anchor is mounted to a distal end of the inserting device. For activation of the anchor, the inserting device can remain engaged with the anchor, the sutures are tensioned, and the anchor deploys as it collapses. 
     These and other features of the present invention will become more apparent from a review of the following detailed description taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a drill guide assembly of the present invention; 
         FIG. 2  is a greatly enlarged fragmentary perspective view of a portion of the drill guide assembly including a bone drill used with the assembly; 
         FIG. 3  is an enlarged fragmentary exploded perspective view of the bone drill; 
         FIG. 4  is a perspective view of the drill guide assembly positioned for use in a surgical procedure for repair of a torn rotator cuff; 
         FIG. 5  is a perspective view of the patient&#39;s shoulder area shown also in  FIG. 4 , illustrating a bone tunnel as drilled by the drill guide assembly, and the drill bit tip being used as an anchor for sutures; 
         FIG. 6A  is a greatly enlarged portion of  FIG. 5  illustrating the drill bit tip used as the anchor; 
         FIG. 6  B is another greatly enlarged portion illustrating an alternate suture arrangement for emplacement of the drill bit tip as an anchor; 
         FIG. 7  is a greatly enlarged perspective view of a suture especially adapted for use in the apparatus and method of the present invention; 
         FIG. 8  is another greatly enlarged fragmentary perspective view of a patient&#39;s shoulder area illustrating a pair of bone tunnels, and pairs of accompanying hardware to include corresponding bone anchors and soft tissue anchors; 
         FIG. 9  is a plan view of a drill guide assembly and a cross sectional view of a cannulated marking hook of the assembly in another embodiment of the present invention; 
         FIG. 10  is a plan view of an alternate embodiment for a drill guide of the drill guide assembly wherein the drill guide includes a pair of offset bores; 
         FIG. 11  is a cross sectional view of another embodiment of a cannulated marking hook of the drill guide assembly; 
         FIG. 12  is a greatly enlarged perspective view of an implantable anchor in another aspect of the present invention; 
         FIG. 13  is another perspective view of the implantable anchor of  FIG. 12 , illustrating sutures attached to the implantable anchor; 
         FIG. 14  is a perspective view of an emplacement tool and the implantable anchor; 
         FIG. 15  is a perspective view of the implantable tool mounted on the emplacement tool; 
         FIG. 16  is a perspective view of the drill guide assembly and the implantable anchor and emplacement tool prior to insertion within the drill guide; 
         FIG. 17  is an enlarged view of the shoulder area illustrating a bone tunnel, and the implantable anchor passed through the bone tunnel and positioned for attachment to the bare area on the humeral head; 
         FIG. 18A  illustrates the implantable anchor mounted over the tool prior to expansion of the anchor; 
         FIG. 18B  illustrates the implantable anchor as it is deployed; 
         FIG. 18C  is another illustration of the implantable anchor as fully deployed; 
         FIG. 19  illustrates the implantable anchor as fully deployed; 
         FIG. 20  is an enlarged perspective view of a suture and mesh usable in the apparatus and method of the present invention; 
         FIG. 21  is another perspective view of the suture and mesh with the mesh being partially deployed; 
         FIG. 22  illustrates the suture and mesh combination of  FIGS. 20 and 21  as fully deployed, along with additional sutures used through tunnels to secure the mesh; and 
         FIG. 23  is a perspective view of the suture and mesh combination as installed for repair of a rotator cuff injury. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , the drill guide assembly  10  of the present invention is illustrated. The drill guide assembly includes a marking hook  12 , a drill guide  14 , and an angle setting arm  18 . The angle setting arm  18  is secured to one lateral side of a drill guide mount  16 . The drill guide  14  is received longitudinally through the drill guide mount  16  and is secured through an open slot in the drill guide mount as by a plurality of set screws  40 . The marking hook  12  is secured to the angle setting arm  18  by a marking hook mount  20  which is received at a selected slidable location along the angle setting arm  18 . A fastener, such as a wing nut or screw  22  tightens the marking hook mount  20  to a selected angular location along the angle setting arm  18 . A plurality of angular gradations  24  are marked along the angle setting arm  18  that assists a practitioner in setting the correct location for the marking hook  12 . More specifically, a practitioner must determine the length L of the bone tunnel to be drilled through the humeral head. This length L is defined as the gap between the hook point  30  of the marking hook  12  and the distal end of the drill guide  14 . The practitioner also selectively locates the position of the drill guide  14  in terms of how far the distal end of the drill guide extends from the drill guide mount  16 . 
     The marking hook  12  is further characterized by a base  34  that comprises a straight shaft extending from the marking hook mount  20 . The distal end of the base transitions into an arcuate extension  32  that is especially adapted to accommodate the curvature of the humeral head. The arcuate extension  32  is especially shaped to accommodate the shape of the humeral head. The radius of curvature of the humeral head ranges from 20 mm to 30 mm. As shown, the extension  32  has a radius R that can be sized in the 20-30 mm range that allows the surgeon to pass the marking hook arthroscopically around the humeral head and onto the bare area of the far cortical bone. The shape of the extension  32  can be defined as an arc or semi-circle that traverses approximately 180 degrees. This uniquely shaped extension is designed specifically for the humeral head which has a shape that is very different from the other joints in the human body. The marking  12  can also have different shapes for right versus left shoulders, thus allowing for passage of the marking hook into the glenohumeral joint along the anterior capsule.  FIG. 1  shows the shape of the marking hook  12  as best suited for a right side joint. The hook point  30  extends from the distal tip of the arcuate extension  32  and as shown, the hook point  30  extends in a general direction towards the distal end  44  of the drill guide  14 . 
     Referring also to  FIG. 2 , the drill guide  14  is characterized as having a shaft  48  with a central bore  80  extending therethrough. The proximal end of the drill guide includes an enlarged portion  46  having an increased internal diameter opening for receiving a bone drill  60 . 
     In accordance with the bone drill  60  of the present invention, it includes a drill shaft  62  and a removable drill bit tip  66 . The drill bit tip  66  may have a slightly larger diameter than the drill shaft  62  such that only the drill bit tip  66  cuts through the bone while the drill shaft  62  remains slightly spaced from the bone. The distal end of the drill shaft  62  includes a threaded extension  64  that is inserted within a threaded well  68  of the drill bit tip  66 . When the drill bit tip  66  is secured to the drill shaft  62 , planar surface  70  of the drill bit tip  66  abuts the facing planar surface  72  of the drill shaft  62 . 
     The particular shape of the drill bit tip  66  is characterized by a plurality of flutes  76  that are formed with a helical pattern on the exterior surface of the drill bit tip  66 . The distal tip of the bit tapers to form a generally transverse extending cutting edge  78 . The drill bit tip  66  also includes a transverse aperture or opening  74  that extends completely through the tip  66 . One acceptable size for the drill bit tip  66  is one that has a diameter of approximately 2.5 mm and is approximately 5.0 mm in length. 
     Referring to  FIG. 4 , the drill guide of the present invention is illustrated as it is positioned for use in a rotator cuff repair. To conduct the repair, first the rotator cuff is held in position, such as by a conventional tissue grasping tool (not shown) that has been inserted through the skin and deltoid muscle of the patient to reach the rotator cuff. Once the rotator cuff is in place, then the drill guide of the present invention can be positioned. The practitioner may first locate the marking hook  12  to the desired position on the far cortex of the humeral head by inserting the marking hook through the tissue in the patient and placing the tip  30  on the desired exit point on the far cortex. The practitioner may then position the distal end  44  of the drill guide  14  on the selected location where the practitioner desires to drill the tunnel. The distal end  44  of the drill guide is then passed through the skin, deltoid muscle, and rotator cuff to contact with the humeral head. 
     The practitioner drills a first bone tunnel by inserting the drill  60  through the bore  80  to drill the bone tunnel. The drill bit tip  66  exits the far end of the cortex and is placed directly adjacent the hook point  30 . The marking hook  12  is then manipulated to insert the hook point  30  through the aperture  74  in the drill bit tip  66 . The drill shaft  62  is then unscrewed from the drill bit tip  66  thereby leaving the drill bit tip  66  in place as attached to the hook point  30 . The use of a cannulated marking hook and drill guide for passing of a relay material can facilitate the passing of sutures. A cannulation running down the length of the marking hook allows the surgeon to pass the relay material to the exit site of the drill. This method and physical guide would allow the surgeon to pass suture to the new tunnel placement and allow for a grasper to be used down the bone tunnel (and possibly the drill guide) to retrieve the suture in sequential steps. The drill guide can have multiple drilling bores to accommodate different spacing for adjacent bone tunnels and can still incorporate the use of the same marking hook. 
     Referring to  FIG. 5 , the first bone tunnel  86  is illustrated extending through the humeral head. At this point, the practitioner may pass one or more sutures  88  through the bone tunnel  86 . Referring also to  FIG. 6A , the sutures  88  are passed through the bone tunnel, through the aperture  74  in the drill bit tip, and then are secured to the drill bit tip  66  as by a knot  89  that is tied. As shown in  FIG. 6A , the drill bit tip  66  is located on the bare area  110  on the humeral head  102  and extends transversely across the opening in the bone tunnel to prevent the tip  66  from being pulled back through the tunnel. Accordingly, the length of the tip  66  is preferably longer than the diameter of the tip so the tip can be used as the transversely placed anchor. By this procedure, the drill bit tip serves the dual purpose of drilling the bone tunnel and as the anchor. The opposite ends of the sutures can be attached to the soft tissue around the rotator cuff, such as by soft tissue anchors  84 . 
       FIG. 6B  illustrates a modified drill bit tip  66  having a pair of apertures  74 . In another method of repair as shown in this Figure, the sutures are passed through the tunnel, through one aperture  74 , back through the other aperture  74 , and then back through the tunnel so that the free ends of the sutures are all tied along the superior aspect of the greater tuberosity. Thus, there are no knots located at the tip/anchor  66  that further simplifies the procedure by only requiring suture knots/arrangements at the more easily viewed position along the superior aspect of the greater tuberosity. 
     Referring to  FIG. 7 , in accordance with another aspect of the present invention, a suture  120  is provided that is especially adapted for use in securing sutures in place thereby minimizing staples and other hardware. As shown in  FIG. 7 , the suture  120  comprises a plurality of fibers woven together to form unexpanded portions  122  interspersed with a plurality of expanded portions  124 . The expanded portions are characterized by a head or protuberance  126 , a gradual sloping front edge, and a more sharply narrowing back edge  128 . The expanded portions are formed by separating or pulling the strands of material apart from the more tightly woven group of fibers in the unexpanded portions  122 . The head or protuberance  126  is tapered with respect to the longitudinal axis of the suture  120 . 
     As shown with the directional arrows, the suture can be passed through the bone tunnel or tissue in the direction from right to left as shown in  FIG. 7 ; however, the suture incorporates a grasping feature which prevents pullout in the direction from left to right. This grasping feature is achieved by the geometry of the suture in which the heads  126  engage the interior surface of the bone tunnel to prevent movement of the suture from within the bone tunnel. This pullout or anchoring feature therefore allows a practitioner to incorporate the suture through the bone tunnel and increase frictional resistance of the suture in the bone tunnel that therefore minimizes the forces transmitted to both the anchor  66 , as well as the hardware used to secure the sutures over the deltoid muscle after the procedure has taken place. The diameter of the suture can be chosen to match the bone tunnel to be drilled so that optimal frictional resistance is achieved between the suture and the bone tunnel. 
     Referring to  FIG. 8 , a rotator cuff repair is illustrated with reference to a pair of bone tunnels  86 , and a corresponding pair of suture groups, drill bit anchors  66 , and soft tissue anchors  84 . It shall be understood that the practitioner has the option of creating the requisite number of bone tunnels and suture configurations in order to repair the particular rotator cuff injury. 
     In accordance with another method of the present invention, the sutures can be passed through one or more bone tunnels after being secured along the far cortical bone, then passed through the cuff, tied over the cuff tendon, and then passed through one or more additional bone tunnels along the lateral aspect of the greater tuberosity back to the far cortical bone. 
     One particularly challenging type of rotator cuff repair is the repair of a partial thickness cuff tear. An in situ repair can be accomplished with the drill guide of the present invention by placing the drill guide  14  on top of the tear, passing the drill bit through the tendon, passing the sutures through the transosseous tunnels and tying knots on top of the tendon. As understood by the skilled surgeon, it is very difficult to pass an anchor across the partially intact cuff since the landmarks are hidden from arthroscopic view. The emplacement of the marking hook on the tear therefore obviates the need to see the tuberosity and provides a precise aiming point for the drill without further imaging and without further incisions made to view the landmarks. 
       FIG. 9  illustrates a modification to the drill guide assembly  10 , which includes a cannulated marking hook  12  characterized by a continuous orifice that extends through the marking hook  12 . The marking hook  12  as shown also includes a suture  142  that passes through the orifice  140 , such that one end of the suture  142  extends through an opening  144  that communicates with the orifice  140 .  FIG. 9  also illustrates a grasping tool  146  having a handle  148  allowing the practitioner to grasp one end of the tool and insert it through the opening in the drill guide  14 . Grasping tines  150  located at the distal tip of the tool  146  can then grasp the protruding end of the suture  142 , so that it may be passed through the bone tunnel for purposes of suturing the tissue to be repaired in the surgical procedure. 
     Also in reference to  FIG. 9 , the cannulated marking hook  12  allows for any other type of relay material to be passed adjacent the exit point of the drill, such as PDS or nitinol wire. The close proximity of the exit point of the drill therefore allows for a blind retrieval of the relay material and subsequent suture passing, with a minimized need for visualizing the area. In other words, because the drill tip will intersect the marking hook tip, use of a tool like the illustrated grasping tool  146  allows a practitioner to easily retrieve relay material in somewhat of a blind fashion which thereby greatly eases in the commencement of the suture passing. 
       FIG. 10  illustrates a modified drill guide  14  including a pair of bores  160 . This dual set of bores within the drill guide  14  allow the practitioner additional options in setting offset distances to accommodate different drill positions to address different rotator cuff tear patterns. 
     Referring to  FIG. 11 , another modification is shown to the marking hook  12 . This modification includes two separate orifices  140  that extend completely through the marking hook  12 . One of the orifices  140  terminates at intermediate opening  176 . The other orifice terminates at distal opening  174 . As also shown in the figure, two sets of sutures  172  extend through the orifices  140 . A marking hook having multiple offset ending points at the openings  174  and  176  allows for convenient relay retrieval at different designated offset aiming points. For example, there may be multiple bone tunnels formed through the humeral head, and it may be necessary to relay sutures through each of the bone tunnels. The openings  174  and  176  may be centered over the bone tunnels previously drilled, which therefore allows for convenient relay retrieval without having to reposition the marking hook numerous times. 
     Referring to  FIGS. 12 and 13 , in another aspect of the invention, an implantable anchor is provided that can be used to anchor sutures, such as those that extend through a bone tunnel. The implantable anchor  180  includes a cylindrical shaped body/cage  182 , and a plurality of circumferentially spaced and longitudinally extending slits or openings  186 . Approximately midway between the distal end  188  and the proximal end  190  of the anchor is a weakened area forming a score line  192 . Adjacent the distal end  188  of the anchor are a plurality of openings  184  that receive one or more sutures  194 , as shown in  FIG. 13 . 
     Referring to  FIG. 14 , an inserting tool  200  is shown that is used to emplace the anchor  180 . The inserting tool  200  includes a proximal body  202 , a distal tip  206  having a diameter which is less than the body  202 , as defined by the shoulder  204  which delineates the distal end of the body  202  and the proximal end of the tip  206 . 
     Referring also to  FIG. 165 , the anchor  180  is positioned over the tip  206 , and the sutures  194  extend proximally as shown. 
     Referring to  FIG. 16 , the anchor  180  is shown in its mounted position over the tool  200 , and the tool  200  is then inserted through the drill guide  14 . The tool  200  has a length which accommodates the combined length of the drill guide  14  and bone tunnel  86 , so that the anchor  180  can be placed completely through the bone tunnel and beyond the far side of the joint, as shown in  FIG. 17 . Once the anchor  180  has cleared the bone tunnel, the anchor can be activated to secure the sutures. One method of employment of the anchor is to keep the anchor  180  mounted over the tool  200  as explained below with respect to  FIGS. 180A through 18C . Another method of employment is to release the tool  200  from engagement with the anchor  180  after the anchor  180  has passed through the bone tunnel, as also explained below. 
     In order to deploy the anchor  180 , the practitioner will pull proximally on the sutures  194  thereby placing them in tension, and causing the anchor  180  to collapse along the score line  192 . As shown in  FIG. 18A , the sutures are initially without tension, and then tension is placed upon them as shown in  FIG. 18B  causing the collapse of the anchor. Referring to  FIG. 18C , tension is continually applied to fully collapse the anchor along the score line  192 . As the anchor collapses, it increases in overall diameter, thereby preventing the anchor  180  from being pulled back through the bone tunnel. Preferably, the diameter of the anchor  180  is just slightly smaller than the diameter of the bone tunnel, such that minimal collapse of the anchor will prevent it from being pulled back through the bone tunnel. The length of the anchor  180  can be approximately 10 mm in length, which will accomplish the necessary anchoring capability for most bone tunnels. 
     As shown in  FIG. 19 , the anchor  180  has been deployed to its fully collapsed position. The sutures  194  can then be tied/secured at the opposite end of the bone tunnel. 
     Although only two pairs of sutures  194  are illustrated, additional sutures may be secured through the openings  184  in the anchor  180 , depending upon the manner in which the sutures are used for the specific surgical procedure. It is clear from the figures that it is only necessary for one suture  194  for activation/deployment of the anchor  180 . It is noted in  FIG. 17  that the tool  200  is not illustrated, it being understood that the tool  200  would extend completely through the bone tunnel, and would remain in engagement with the anchor  180  until the anchor was expanded in a diameter to prevent pull back through the bone tunnel  86 . 
     Referring to  FIG. 20 , in another aspect of the invention, a suture construction is provided in the form of a mesh canopy  222  that can be initially retained on a conventional suture  220 . 
     As shown in  FIG. 21 , the mesh canopy  222  can be unfurled from a rolled position about the supporting suture  220 . The mesh canopy  222  can then be appropriately positioned over the damaged tissue in order to provide a much larger area for support, as compared to a conventional suture arrangement. 
     As shown in  FIG. 22 , once the mesh canopy  222  has been deployed, it may extend away from the supporting suture  220  in a fashion to provide greater coverage over a targeted area. A plurality of openings  224  may be formed around the edge of the mesh canopy  222 , and these openings  224  may receive a desired set of sutures  226  that may pass through bone tunnels formed in the joint, as shown in  FIG. 23 . 
     In the example of  FIG. 23 , there are four bone tunnels that have been provided through the bone structure, and the pairs of sutures  226  extend in a looped fashion through adjacent pairs of the bone tunnels. The sutures  226  can then be secured over the mesh  222  as by use of securing knots  228 . Optionally, the supporting suture  220  may also be secured to the tissue as by tissue anchors  84 . 
     It is clear from the present invention that an effective repair of a rotator cuff injury can be achieved that minimizes traditional bone anchors, and rather incorporates a minimal amount of hardware and simplifies suture arrangements. 
     Thus, in accordance with the present invention, a rotator cuff repair can be achieved where anchoring of the sutures avoids the cancellous bone mass located beneath the near cortex of the bone in favor of anchoring the sutures at the far cortex of the bone that has a higher bone density. By the use of an especially adapted marking hook, the bone tunnels can be very precisely determined enabling more than one bone tunnel to be created through the bone mass in order to handle the particular rotator cuff injury at hand. Separate bone anchors are replaced in favor of anchoring sutures by the drill bit tip  66  on the far cortex. 
     Also in accordance with the present invention, unique suture constructions are provided that provide a practitioner with many options for stabilizing torn tissue to include minimizing the stresses produced on bone and soft tissue anchors. A unique anchor is also provided that can be deployed without the use of further instruments, and which is introduced directly through the bone tunnels. 
     Furthermore, the method of the present invention can be achieved with a minimum of instruments thereby making the procedure of the present invention more susceptible to repeatability and reliability. 
     While the present invention has been described with respect to preferred embodiments in accordance with the apparatus and method of the present invention, various other changes may be made within the scope of the claims appended hereto.