Patent Publication Number: US-2012041484-A1

Title: Medical device and procedure for attaching tissue to bone

Description:
RELATED APPLICATIONS 
     This application is a non-provisional of U.S. provisional patent application No. 61/382,170 filed Sep. 13, 2010, U.S. provisional patent application No. 61/414,686 filed Nov. 17, 2010, U.S. provisional patent application No. 61/431,570 filed Jan. 11, 2011, and U.S. provisional patent application No. 61/443,023 filed Feb. 15, 2011, all of which are incorporated herein fully by reference and to which the present application claims priority. This application also is a continuation-in-part of U.S. patent application Ser. No. 12/729,769 filed Mar. 23, 2010, which also is incorporated herein fully by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to medical devices and procedures for attaching tissue to bone. 
     The invention relates particularly to medical devices and to medical procedures incorporating the use of the medical devices, that can be used in the repair of tendon tears and the like, where repair requires the reattachment of soft tissue to skeletal structures, i.e. bones. 
     BACKGROUND OF THE INVENTION 
     Rotator cuff tears often require reattachment of soft tissue to skeletal structures and the explanation of the invention as hereinafter set out refers particularly to the repair of rotator cuff injuries, although it must be understood that the invention can be employed also in association with other like injuries where similar repair techniques are ordinarily employed or considered. The rotator cuff is the anatomical term given to a group of muscles and their tendons that act to move and stabilize the shoulder. These muscles extend from the scapula, i.e. the shoulder blade bone, and connect to the humerus, i.e. the upper arm, via their tendons, forming a cuff at the shoulder joint, thus serving to control different arm movements. A rotator cuff tear can result from a trauma to a shoulder or through wear and tear and be associated with one or more tendons becoming torn, leading to pain, shoulder instability and/or restricted arm movement. 
     Rotator cuff repair involves a surgeon reattaching each damaged tendon to the humerus. The conventional surgical process typically includes the steps of gaining access to the injured rotator cuff by making an incision in the shoulder and splitting the deltoid muscle and then removing scar tissue that has built up on each torn tendon. The surgeon then creates a trough at the top of the humerus and drills small holes through the bone, whereafter he sews the tendon to the bone with sutures passing through the holes. Other steps also may be associated with the process in order to deal with specific repair requirements. Following the process, the arm is incapacitated and healing is allowed to occur, which involves the reattachment of the tendons to the bone and which is generally a slow process. 
     Instead of passing sutures through holes drilled in the humerus for securing the tendon to the humerus, it is also known to use permanent anchors with sutures attached, inserted in the humerus, for this purpose. 
     More recently, arthroscopic surgery is being employed for rotator cuff repair. The surgery is performed through one or more small incisions. The surgeon observes the area of interest via a display screen which displays live images from a camera that is placed in a tube (cannula) passing through a small incision into the joint space. The instruments used are thin and are contained in separate cannulas that are inserted into the shoulder via separate small incisions. This arthroscopic surgery process includes placing anchor devices to which sutures are engaged for securing tendons to the humerus. In some techniques a pilot hole is required prior to placement of an anchor device. Each suture is passed through the tendon with a suture passing instrument. In most cases, all of the sutures are passed before tying. The sutures are then tied to anchor devices by the technique of arthroscopic knot tying. Various difficulties are associated with arthroscopic surgery as above envisaged. 
     The location of and the angle of a pilot hole for an anchor device is difficult to appreciate arthroscopically, rendering the location of anchor devices in their holes difficult. 
     The tying of sutures arthroscopically is very challenging. 
     Insofar as suture management is concerned, present techniques often require multiple sutures to be placed in position first and then to be tied to their anchor devices, often creating a “spider web” with entanglement of sutures and resulting in accidental pull-out of sutures and failure to recognize appropriate suture strands to be tied. Placing of sutures also presents difficulties insofar as multiple passes through the tendon are often required and snaring of suture portions by the soft tissue forming a tendon also can occur, resulting in difficulty in retrieving sutures into the portal of the equipment used. 
     SUMMARY OF THE INVENTION 
     The invention pertains to methods and apparatus for attaching tissue to bone. Particularly, the invention relates to bone anchors for receiving (or being pre-loaded with) sutures for connecting to soft tissue that is to be attached to bone. The invention further includes tools for implanting the bone anchors and facilitating the attachment of soft tissue to bone via the bone anchors and procedures for using the same. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features of the various aspects of the invention are described hereinafter with reference to the accompanying diagrammatic drawings. In the drawings: 
         FIG. 1  shows a side view of an anchor main body forming a part of a first embodiment of a bone anchor device for anchoring a suture engaged with soft tissue to a bone in accordance with the invention; 
         FIG. 2  shows a top view of the anchor main body of  FIG. 1 ; 
         FIG. 3  shows a cross-sectional side view of the anchor main body of  FIG. 1 , along line III-III of  FIG. 2 ; 
         FIG. 4  shows a side view of an eyelet pin forming a further part of the first embodiment of the bone anchor device of which the anchor main body of  FIG. 1  forms a part, the eyelet pin being configured to cooperate with the anchor main body of  FIG. 1 ; 
         FIG. 5  shows a perspective view of a tissue fastener device for use in a medical procedure associated with the use of a medical device including the anchor main body of  FIG. 1  and the eyelet pin of  FIG. 4 ; 
         FIG. 6  shows a top view of the tissue fastener medical device of  FIG. 5 ; 
         FIG. 7  shows a side view of the tissue fastener medical device of  FIG. 5 ; 
         FIGS. 8 to 12  schematically illustrate steps associated with a first medical procedure for attaching soft tissue to bone and which includes the use of the bone anchor device  FIGS. 1-4  and the tissue fastener device of  FIGS. 5-7 ; 
         FIGS. 13 to 15  schematically illustrate steps associated with a second medical procedure for attaching soft tissue to bone and which includes the use of the bone anchor device of  FIGS. 1-4  and the tissue fastener device of  FIGS. 5-7 ; 
         FIG. 16  illustrates schematically a third procedure for attaching soft tissue to bone and which includes the use of the tissue fastener device of  FIG. 5 ; 
         FIGS. 17 and 18  illustrate schematically the steps associated with a fourth procedure for attaching soft tissue to bone and which includes the use of the tissue fastener device of  FIG. 5 , a suture, and a conventional bone anchor; 
         FIG. 19  shows a cross-sectional side view of an anchor main body forming a part of a second embodiment of a bone anchor device for anchoring a suture engaged with soft tissue to a bone in accordance with the invention; 
         FIG. 20  shows a side view of an eyelet pin forming a part of the second embodiment of the bone anchor device for anchoring a suture engaged with soft tissue to a bone of which the anchor main body of  FIG. 19  forms a part, the eyelet pin being configured to cooperate with the anchor main body of  FIG. 19 ; 
         FIG. 21  shows a side view of an anchor main body forming a part of a third embodiment of a bone anchor device for anchoring a suture engaged with soft tissue to a bone in accordance with the invention; 
         FIG. 22  shows a top view of the anchor main body of  FIG. 21 ; 
         FIG. 23  shows a cross-sectional side view of the anchor main body of  FIG. 21 , along VII-VII of  FIG. 22 ; 
         FIG. 24  shows a side view of an eyelet pin forming a part of the third embodiment of the bone anchor device for anchoring a suture engaged with soft tissue to a bone of which the anchor main body of  FIG. 21  forms a part, the eyelet pin being configured to cooperate with the anchor main body of  FIG. 21 ; 
         FIG. 25  shows the bone anchor device of  FIGS. 19-24  in the closed state; 
         FIG. 26  shows a cross-sectional side view of an anchor main body and eyelet pin of the third set of embodiments of a medical device for anchoring a suture engaged with soft tissue to a bone in accordance with the invention, the pin being located in its closed configuration within a receiving formation defined by the anchor main body; 
         FIGS. 27 and 28  illustrate schematically a fifth procedure for attaching soft tissue to a bone and which includes the use of the second embodiment of the bone anchor device as illustrated in  FIGS. 19 and 20 ; 
         FIGS. 29 and 30  illustrate schematically a sixth procedure for attaching soft tissue to a bone and which includes the use of both the second embodiment of the medical device as illustrated in  FIGS. 19 and 20  and the third embodiment of the medical device as illustrated in  FIGS. 21 to 24 ; 
         FIGS. 31 and 32  illustrate a variation of the procedure illustrated in  FIGS. 29 and 30  in accordance with the invention; 
         FIGS. 32 to 35  illustrate three further procedures for attaching soft tissue to a bone and which include the use of bone anchor device in accordance with the invention; 
         FIG. 36  shows a cross-sectional side view of a bone anchor device in the open state in accordance with a fourth embodiment of the invention for anchoring a suture engaged with the soft tissue to a bone; 
         FIG. 37  shows a cross-sectional side view of the bone anchor device of  FIG. 36  in the closed state; 
         FIG. 38  shows a perspective view of the anchor main body portion of the bone anchor device of  FIG. 36 ; 
         FIG. 39  shows a side view of the eyelet pin of the bone anchor device of  FIG. 36 ; 
         FIG. 40  shows a perspective view of a C-ring that can be employed as the locking ring of the bone anchor device of  FIG. 36 ; 
         FIG. 41  shows a perspective view of the retainer of the bone anchor device of  FIG. 36 ; 
         FIG. 42  shows a cross-sectional side view of a bone anchor device in the open state in accordance with a fifth embodiment of the invention; 
         FIG. 43  is a cross-sectional side view of the bone anchor device of  FIG. 42  in the closed state; 
         FIG. 44A  shows a close-up view of the eyelet of the eyelet pin in accordance with a first alternate embodiment of the bone anchor device of  FIG. 36  in the open state (sixth set of embodiments); 
         FIG. 44B  shows a close-up view of the eyelet of the eyelet pin in accordance with the first alternate embodiment of the bone anchor device of  FIG. 36  in the closed state; 
         FIG. 44C  shows a close-up view of the eyelet of the eyelet pin in accordance with a second alternate embodiment of the bone anchored device of  FIG. 36  in the open state; 
         FIG. 44D  shows a close-up view of the eyelet of the eyelet pin of the bone anchor device in accordance with the second alternate embodiment of  FIG. 36  in the closed state; 
         FIG. 44E  shows a perspective view of the cylinder of the second alternative embodiment of  FIGS. 44C and 44D  separate from the overall device; 
         FIG. 44F  shows a further embodiment of the eyelet pin of the bone anchor device in cross-section in the closed state; 
         FIG. 45  is a semi-transparent perspective view of a driver for driving a bone anchor device into bone in accordance with an embodiment of the present invention; 
         FIG. 46  is a semi-transparent side view of an impactor tool for driving the center pin of a bone anchor device of the present invention from the open position to the closed condition in the anchor main body of the bone anchor device; 
         FIG. 47  is a close-up, semi-transparent view of the proximal end of the impactor tool of  FIG. 46 ; 
         FIG. 48  is a close-up, semi-transparent view of the distal end of the impactor tool of  FIG. 46 ; 
         FIG. 49  shows a perspective view of an alternate locking ring to that illustrated in  FIG. 40 ; 
         FIG. 50  shows a cross-sectional side view of a bone anchor device in the open state in accordance with a seventh embodiment of the invention; 
         FIG. 51  shows a cross-sectional side view of a bone anchor device in the closed state in accordance with the seventh embodiment of the invention shown; 
         FIG. 52A  shows a perspective view of an eyelet pin in accordance with an eighth set of embodiments of the invention; 
         FIG. 52B  shows a top plan view of the eyelet pin in accordance with the eight set of embodiments of the invention; 
         FIG. 53  shows a cross-sectional side view of the anchor main body in accordance with the eighth set of embodiments of the invention; 
         FIG. 54A  shows a perspective view of a bone anchor device and corresponding implantation device in accordance with the eighth set of embodiments of the invention; 
         FIG. 54B  shows a cross-sectional side view of the bone anchor device and corresponding implantation device in accordance with the eighth set of embodiments of the invention; 
         FIG. 55A  shows a cross-sectional side view of the proximal end of the implantation device in accordance with the eighth set of embodiments of the invention; 
         FIG. 55B  is an exploded view of the proximal end of the implantation device in accordance with the eighth set of embodiments of the invention; 
         FIG. 56A  is an exploded view of the distal end of the implantation device with the implantable bone anchor in accordance with the eighth set of embodiments of the invention; 
         FIG. 56B  shows a cross-sectional side view of the distal end of the implantation device and the implantable bone anchor taken through section B-B in  FIG. 55A ; 
         FIG. 56C  shows a cross-sectional side view of the distal end of the implantation device and the proximal portion of the implantable bone anchor taken through section C-C in  FIG. 55A ; 
         FIG. 57A  is a perspective view of an implantation device including the implantable device and a suture shuttle in accordance with a ninth set of embodiments; 
         FIG. 57B  is a perspective view of a suture shuttle in accordance with the ninth set of embodiments; 
         FIG. 57C  is a close up view showing the ends of alternative suture shuttles in accordance two alternate embodiments of a suture shuttle; 
         FIG. 57D  is a close up perspective view of the proximal end of the implantation tool handle in accordance with the ninth set of embodiments showing an alternative aperture arrangement; 
         FIG. 57E  shows the tool of  FIG. 57A  during a first stage in which sutures are being loaded into the suture shuttle; 
         FIG. 57F  shows the tool of  FIG. 57A  during a second stage in which sutures are being loaded into the suture shuttle; 
         FIG. 57G  shows the tool of  FIG. 57A  during a third stage in which sutures are being loaded into the suture shuttle; 
         FIG. 57H  shows the tool of  FIG. 57A  during a fourth stage in which sutures are being loaded into the suture shuttle; 
         FIG. 57I  shows the tool of  FIG. 57A  during a fifth stage in which sutures are being loaded into the suture shuttle; 
         FIG. 57J  shows the tool of  FIG. 57A  during a sixth stage in which sutures are being loaded into the suture shuttle; 
         FIG. 57K  is a cross-sectional side view of the handle of the implantation tool in accordance with the ninth set of embodiments illustrating an alternate embodiment including a cap; 
         FIG. 58  is a close up view of the suture shuttle in accordance with the ninth set of embodiments passing through the eyelet of the eyelet pin; 
         FIG. 59  is a perspective view of the implantation tool in accordance with the ninth set of embodiments bearing a protective sheath; 
         FIGS. 60A-60C  illustrate an alternate embodiment of the proximal portion of an implantation tool at various stages of use in accordance with the ninth set of embodiments; 
         FIGS. 61A and 61B  illustrate yet another alternate embodiment of the proximal portion of an implantation tool in accordance with the principles of the ninth set of embodiments; 
         FIG. 61C  illustrates one more alternate embodiment of the proximal portion of an implantation tool in accordance with the ninth set of embodiments; 
         FIG. 62  is a top plan view of an exemplary bone anchor in accordance with a tenth set of embodiments; 
         FIG. 63  is a side cross-sectional view of another exemplary bone anchor in accordance with the tenth set of embodiments; 
         FIG. 64A  is a perspective view of an exemplary adjustment/redeployment tool that may be used to adjust or redeploy a bone anchor in accordance with the principles of the present invention; 
         FIG. 64B  is another perspective view of the tool of  FIG. 64A  with the handles removed; and 
         FIG. 65  is a cross-sectional side view of a bone anchor device in accordance with an eleventh set of embodiments of the invention; 
         FIG. 66A  is a perspective view of another embodiment of an implantation tool in an assembled condition; 
         FIG. 66B  is another perspective view of the implantation tool of  FIG. 66A  showing the combined suture cleat and thumb rest in exploded view; 
         FIG. 66C  is a side view of the suture cleat/thumb-rest of the implantation tool of  FIGS. 66A and 66B ; 
         FIG. 67  is a perspective view of a threader that may be employed in the use of the implantation tool; 
         FIG. 68A  shows an alternate embodiment of the tool of  FIG. 57A  being used in connection with the threader of  FIG. 67  during a first stage in which sutures are being loaded into the suture shuttle; 
         FIG. 68B  shows the alternate embodiment of the tool of  FIG. 57A  being used in connection with the threader of  FIG. 67  during a second stage in which sutures are being loaded into the suture shuttle; 
         FIG. 68C  shows the alternate embodiment of the tool of  FIG. 57A  being used in connection with the threader of  FIG. 67  during a third stage, in which sutures are being loaded into the suture shuttle; 
         FIG. 69A  is a perspective view of an alternate embodiment of the implantation tool having suture loading near the distal end of the handle; 
         FIG. 69B  is a perspective view of the threader member of the tool of  FIG. 69A ; 
         FIG. 69C  is a perspective view of the aperture member of the tool of  FIG. 69A ; 
         FIG. 69D  is a perspective view of the threader member assembled to the aperture member as it would be when the tool is assembled in its pre-surgical condition; 
         FIG. 69E  is a close up view of the distal portion of the handle of the tool of  FIG. 69A  in a fully assembled, pre-surgical state; 
         FIG. 69F  is a cross-sectional view through section B-B in  FIG. 69E ; 
         FIG. 69G  is a perspective view of the handle after the threader member has been withdrawn; 
         FIG. 69H  is a perspective view of the distal portion of the handle after the aperture member has been withdrawn; 
         FIG. 69I  is a side view of an alternate embodiment of a threader member; 
         FIG. 70A  is a cross-sectional view similar to that of  FIG. 70A  of yet another alternate embodiment of an implantation tool having suture loading near the distal end of the handle in a first condition; and 
         FIG. 70B  is another cross-sectional view of the embodiment of  FIG. 70A , but in a second condition. 
         FIG. 71A  is a cross-sectional side view of a bone anchor device in the open state in accordance with an alternative mechanism for retaining the eyelet pin and central pin within the anchor main body. 
         FIG. 71B  is a cross-sectional side view of a bone anchor device in the closed state in accordance with an alternative mechanism for retaining the eyelet pin and central pin within the anchor main body. 
         FIG. 71C  is an exploded view of an eyelet pin, central pin, and anchor main body in accordance with yet another embodiment of the invention. 
         FIGS. 71D through 71F  are cross-sectional views of the eyelet pin, central pin, and anchor main body of  FIG. 71C  assembled and in three different stages of engagement. 
         FIG. 72A  is a perspective view of the central pin and eyelet pin of the embodiment of  FIGS. 71A and 71B  shown disembodied from the anchor main body in accordance with a first sub-embodiment thereof. 
         FIG. 72B  is a perspective view of the central pin and eyelet pin of the embodiment of  FIGS. 71A and 71B  shown disembodied from the anchor main body in accordance with a second sub-embodiment thereof. 
         FIG. 73A  is a perspective view of an alternate tool shaft end piece adapted for use with the anchor design of the embodiments of  FIGS. 71A-72B . 
         FIG. 73B  is a perspective view of main body portion of the tool shaft end piece of  FIG. 73A . 
         FIG. 73C  is a perspective view of the anchor retention element and main body of the tool shaft end piece of  FIG. 73A  shown in exploded view. 
         FIG. 74  is a perspective view of an anchor main body in accordance with the embodiments of  FIGS. 72A-73B . 
         FIG. 75  shows the assembly of the tool shaft end piece of the embodiment of  FIGS. 72A-74  assembled to the anchor body disembodied from the rest of the tool for clarity. 
         FIG. 76A  is a cross-sectional side view of the tool shaft end piece of  FIG. 73A  attached to an anchor with the eyelet pin in the open position. 
         FIG. 76B  is a cross-sectional side view of the tool shaft end piece of  FIG. 73A  attached to an anchor with the eyelet pin in the closed position. 
         FIG. 76C  is a cross-sectional side view of the tool shaft end piece of  FIG. 73A  attached to an anchor with the eyelet pin in the closed position and the shaft end piece withdrawn proximally to prepare the anchor for release from the tool. 
         FIG. 76D  is a cross-sectional side view of the tool shaft end piece of  FIG. 73A  attached to an anchor with the eyelet pin in the closed position, the shaft end piece withdrawn proximally to prepare the anchor for release from the tool, and the tool released from the anchor main body and ready to be withdrawn. 
         FIGS. 77A-77C  illustrate an alternate embodiment of the implantation tool in accordance with the principles of the present invention. 
         FIGS. 78A and 78B  are cross-sectional views of proximal and distal sections, respectively, of the implantation tool of  FIGS. 77A-77C  during a first stage of anchor deployment. 
         FIGS. 79A and 79B  are cross-sectional views of proximal and distal sections, respectively, of the implantation tool of  FIGS. 77A-77C  during a second stage of anchor deployment. 
         FIGS. 80A and 80B  are cross-sectional views of proximal and distal sections, respectively, of the implantation tool of  FIGS. 77A-77C  during a third stage of anchor deployment. 
         FIGS. 81A and 81B  are cross-sectional views of proximal and distal sections, respectively, of the implantation tool of  FIGS. 77A-77C  during a fourth stage of anchor deployment. 
     
    
    
     DETAILED DESCRIPTION 
     First Set of Exemplary Embodiments 
     A medical system in accordance with a first embodiment of the present invention comprises two primary components, namely, a bone anchor device  1  as shown in  FIGS. 1-4  and a tissue fastener device  2  as shown in  FIGS. 5-7 . 
     Referring initially to  FIGS. 1-4 , a bone anchor device  1  in accordance with the invention is shown for anchoring a suture that is engaged with soft tissue to a bone. It includes a substantially cylindrical body  10  and an eyelet pin  12 . Both the anchor main body  10  and the eyelet pin  12  may be formed of a biocompatible material, such as of a type already commonly used within the body of a person, e.g., a metal or metal alloy such as titanium, stainless steel or cobalt-chrome alloys; a suitable polymeric material that is nonabsorbable, such as polyethylene, poly-ether-ether-ketone (PEEK), poly-ether-aryl-ketone (PEAK); a resorbable polymer selected from homopolymers, copolymers and blends of polylactide, polyglycolide, polyparadioxanone, polytrimethylene carbonate or polycaprolactone; or composites of the aforementioned with biocompatible inorganic substances such as carbon, hydroxyapatite, beta tricalcium phosphate, other calcium phosphate ceramics or calcium sulfate. 
     The anchor main body  10  defines a leading end  14  and a trailing end  16  and an external formation such as a thread  18  extending externally along the length thereof from its leading end towards its trailing end to help secure the body  10  to bone. At its trailing end  16 , the body  10  defines a head formation  20 , the head formation  20  being geometrically profiled to permit engagement with a screw driver-type tool, for screwing the body into a bone. The body  10  also defines a receiving formation therein that is in the form of a cylindrical blind bore  22 , the receiving formation  22  being particularly configured to frictionally receive the eyelet pin  12  therein. 
     The eyelet pin  12  could be formed of the same material as the anchor main body  10 , the pin comprising a substantially cylindrical pin that defines a passage  24  therethrough near a proximal end thereof and a longitudinal slot  26  that extends therein from the distal end toward the proximal end near which the passage  24  is defined. The pin thus defines two legs  28  on opposite sides of the slot  26 . The pin  12  is particularly configured to be securely locatable within the receiving formation  22  defined by the anchor main body  10  by a friction fit, inherent resilient deformability of the material forming the pin and the configuration of the slot serving to enhance required location of the pin within the receiving formation  22  defined by the body  10 . The exact configurations of the anchor main body and of the pin are greatly variable. 
       FIGS. 5-7  illustrate a tissue fastener device  2  for use in conjunction with the bone anchor device  1  in a medical process. The tissue fastener device  2  comprises a body  30  that defines a shank portion  32  and a hook formation  34 , the shank portion  32  having a hole  36  defined therein near the free end thereof. Generally, the configuration of the hook formation is greatly variable, the hook formation  34  in this case being defined by two spaced apart prongs  38 , the free ends of the prongs extending substantially parallel to the shank portion  32 . The hole  36  permits a fastener such as a length of suture or a screw to be attached to the body  30 , whereas the free end of the shank portion  32 , possibly in conjunction with the location of the hole  36 , is configured to be engageable with an applicator tool whereby the body can be manipulated for engaging soft tissue via the hook formation  34 , within a medical procedure, as is explained in more detail hereafter. 
     Insofar as the tissue fastener  2  is configured for use in an arthroscopic procedure, the end region of the shank portion  32  of the body  30  where the hole  36  is defined is configured to engage an engagement formation of an applicator tool, the applicator tool providing for manipulation of the tissue fastener device  2  for engaging soft tissue, particularly via a cannula located in an incision in a body of a person in a location where it provides access to the location where the tissue fastener device  2  must be engaged with soft tissue. Although not essential, it is envisaged that such an applicator tool can be cannulated to provide for a suture to pass through the cannula, thus to provide for the free end of a suture tied to the tissue fastener device  2  to remain conveniently accessible externally of the body of a person following engagement of the device with soft tissue, as is described in more detail hereafter. 
     It must be understood that a specific arthroscopic applicator tool will be provided for use with the tissue fastener device  2  and/or that the tissue fastener device  2 , as described, may require modification for cooperating with a particular tool, in order to facilitate its use as hereafter described. 
     The tissue fastener device  2  may be formed of a metal material of a type already used for medical devices used within the body of a person, e.g., a metal or metal alloy such as titanium, stainless steel and cobalt-chrome alloys; a suitable polymeric material that is nonabsorbable, such as polyethylene, poly-ether-ether-ketone (PEEK), poly-ether-aryl-ketone (PEAK); a resorbable polymer selected from homopolymers, copolymers and blends of polylactide, polyglycolide, polyparadioxanone, polytrimethylene carbonate or polycaprolactone; or composites of the aforementioned with biocompatible inorganic substances such as carbon, hydroxyapatite, beta tricalcium phosphate, other calcium phosphate ceramics or calcium sulfate. 
     First Set of Exemplary Surgical Procedures 
     The bone anchor device  1  and the tissue fastener device  2  are configured particularly for use in a medical procedure for anchoring sutures engaged with soft tissue to a bone, thereby attaching the soft tissue to the bone. Sutures engaged with soft tissue to be anchored to a bone within the procedure may be engaged with the soft tissue by any known method, although for the first procedure described hereafter with reference to  FIGS. 8 to 12 , the sutures are separately tied to the tissue fastener devices  2  of  FIGS. 5 to 7  that are engaged with soft tissue through the engagement of the hook formations  34  of the devices  2  with the soft tissue. 
     The procedure as above envisaged is typically applied in association with rotator cuff repair and is hereinafter described in association with such a repair procedure, although it must be appreciated that the medical devices  1  and  2  as above described also can be used in association with other procedures that require soft tissue to be attached to or re-attached to skeletal structures, i.e., to bone. 
     Rotator cuff repair is required where a tendon that acts to stabilize the shoulder has torn and thus is to be reattached to the humerus, i.e. the upper arm bone, thereby to re-establish normal arm movement. As envisaged above, such repair ordinarily involves a surgeon gaining access to the tendon and the humerus through incision, engaging sutures to the tendon in a conventional manner, and then sewing the sutures to the humerus via holes formed therein for anchoring to the humerus. Anchoring to the humerus by tying the sutures to anchor devices located in the humerus also is known. The same principles apply also to the procedure that is explained hereafter with particular reference to  FIGS. 8 to 12  and that is associated with the use of the medical devices  1  and  2  described above. 
     Referring now to  FIGS. 8 to 12  of the drawings, the rotator cuff repair procedure illustrated particularly is an arthroscopic procedure which includes, as a first step, providing access to the damaged tendon  40  and the humerus  42  by forming one or more incisions in the shoulder region and inserting a cannula  44  in each incision. 
     The general procedure in association with the location of cannulas  44 , which can provide access to required locations to permit the repair procedure to be carried out, is already well known and is thus not described further herein. Each cannula located in an incision provides access to locations where the procedure must be performed, particularly also for arthroscopic tools or instruments that can serve to suitably manipulate the medical devices above described, within the procedure. The configuration of such arthroscopic tools or instruments are generally well known, but insofar as existing tools or instruments may not be specifically configured to accommodate manipulation of the medical devices described, existing tools or implements may be suitably adapted or new tools or instruments may be designed, using known principles, in order to facilitate the procedure. 
     With reference to  FIG. 8 , the first step in the arthroscopic procedure for performing a rotator cuff repair following the location of a cannula that provides access to the humerus  42  provides for the anchor main body  10  of the bone anchor device  1  to be screwed into the humerus  42  in a desired anchoring location. An arthroscopic screw driver engaging the head formation  16  of the anchor main body  10  is used for this purpose, the typical location of the anchor main body being shown in  FIG. 8  of the drawings, which also illustrates the head formation  16  of the body that remains exposed externally of the humerus  42 . For a medical device having an anchor main body without a head formation, this exposure may not occur. It must be understood in relation to this procedure that a further cannula accommodates an instrument carrying a camera, enabling a surgeon to observe the area of interest, particularly via live images displayed on a display screen. Additional anchor main bodies  10  that can form anchors for sutures will be similarly screwed into the humerus  42  before proceeding with the next step in the procedure. 
     With reference to  FIG. 9 , the next step in the procedure provides for tying of individual sutures  46  to the respective bodies  30  of the tissue fastener devices  2 . Alternately, the sutures can be pre-tied to the fastener, or simply looped through hole  36 . Next, the hook formation  34  defined by each body is fastened to, under arthroscopic visualization, the tendon  40  being repaired, particularly again via a suitably located cannula  44  and with the aid of a suitable instrument that permits manipulation of the body  30  to provide for engagement of the hook formation  34  with the tendon. The suture  46  tied to each body  30  optionally may extend centrally through the applicator tool utilized, the free end of the suture thus remaining accessible externally of the person&#39;s body. A suture  46  extending from a body  30  and via a cannula to a location externally of the body is illustrated. The number of sutures engaged with the tendon  40  for its repair clearly is determined by the extent of damage to the tendon. 
     The procedure thus requires anchoring of the sutures  46  to anchor main bodies  10  via eyelet pins  12 , and in this regard it must be understood that each anchor main body and its associated eyelet pin may serve to anchor either a single suture or two or more sutures with respect thereto. With reference to  FIG. 10 , this anchoring procedure includes, for each suture  46 , threading the suture through the passage  24  defined in an eyelet pin  12 , which can be done externally of the body, following which through manipulation of the eyelet pin by means of a suitable arthroscopic applicator tool such as the impactor tool shown in  FIGS. 46-48  and described later, the eyelet pin is inserted through an appropriate cannula and partially inserted into the receiving formation  22  of an anchor main body  10  and the free end of the suture is pulled up through the cannula adjacent the bone anchor device  1 , thus providing the configuration shown in  FIG. 11 . Thereafter, with reference to  FIG. 12 , by applying tension to the suture  46 , the tendon  40  is pulled toward and against the humerus  42  from which it has been torn, thus to effectively place the tendon in abutment with the humerus in a configuration in which re-attachment with the humerus is permitted. While retaining the tension in the suture  46 , the eyelet pin is further displaced into the receiving formation  22  of the anchor main body  10 , particularly to the extent that the entire eyelet pin is located in the receiving formation  22 . This can be achieved by impacting under arthroscopic visualization of the eyelet pin with a suitable impactor tool, such as that shown in  FIGS. 46-48  and described later herein, extending through the cannula  44  and a mallet, the suture  46  being effectively anchored to the anchor main body by being clamped between the anchor main body and the pin. The free end segment of each suture can then be suitably cut-off. Normal finishing procedures associated with arthroscopic surgery can then be performed in order to finally complete the procedure. 
     Second Set of Exemplary Surgical Procedures 
     Referring now to  FIGS. 13 to 15  of the drawings, a variation of the rotator cuff repair procedure as described with reference to  FIGS. 8 to 12  of the drawings, is illustrated. In these Figures, like parts are designated by the same reference numerals as before. The procedure is again an arthroscopic procedure which includes, as a first step, providing access to the damaged tendon  40  and the humerus  42  by forming one or more incisions in the shoulder region and, usually, inserting a cannula in each incision. The same considerations in relation to the location of cannulas apply. 
     In this case, a bone anchor device  1  (including an anchor main body  10  and an eyelet pin  12 ) is provided in combination with at least one suture  46 , threaded through the passage defined at one end of the eyelet pin  12 , and a tissue fastener device  2 , tied to the suture. The eyelet pin  12  is partially inserted in the receiving formation defined therefore in the anchor main body  10 , free displacement of the suture  46  still being permitted. 
     With a cannula  44  being located that provides access to the humerus  42 , the anchor main body  10  of the medical device is again screwed into the humerus in a desired anchoring location. This is achieved in the same way as before and provides the configuration shown in  FIG. 13 , in which the eyelet pin  12 , suture  46 , and body  30  are located as shown. 
     With reference to  FIG. 14 , the next step in the procedure provides for the suture  46  to be attached to the tendon  40  by engagement of the hook formation defined by the tissue fastener device  2  with the tendon, particularly with the aid of a suitable arthroscopic tool operated via the cannula  44 . 1 . Instead of attachment of a suture to a tendon  40  with the aid of a tissue fastener device  2 , the suture alternately can be “tied” to the tendon with the aid of a suitable suture passing instrument (not shown). Insofar as this form of attachment of a suture to a tendon is conventional and well known, it is not described or illustrated in more detail herein. 
     With reference to  FIG. 15 , with the suture  46  attached to the tendon  40 , tension can be applied to the suture for displacing the tendon into its required “repair position” with respect to the humerus  42 , following which the eyelet pin  12  is displaced into its fully inserted (or closed) position in its receiving formation  22  defined by the anchor main body  10 , thus providing for anchoring of the suture  46  to the humerus. Following completion, the excess suture is cut-off. 
     It will be understood that both the above described procedures can be altered in various different respects. For example, for the procedure described with reference to  FIGS. 8 to 12 , it is envisaged that an eyelet pin can be partially inserted (in the open state) in an anchor main body without a suture threaded therethrough, whereafter the suture can be attached to the tendon to be repaired before being threaded through the passage  24  in the eyelet pin  12  and being anchored in position by the full insertion of the eyelet pin in its receiving formation. It must be understood in this regard that the exact procedure followed will be determined by individual procedure requirements and also the nature of the procedure which requires anchoring of sutures to bone with the aid of a medical device. 
     Some of the benefits associated with the use of a tissue fastener device in accordance with the invention within a medical procedure are explained hereafter particularly in relation to a rotator cuff procedure as above described, although it must be understood that some or all of these benefits may be associated also with other procedures as will be clearly apparent. 
     The known state-of-the-art procedures usually require placement of all sutures through the rotator cuff prior to securing of the sutures to the bone. This is necessary because the sutures are deployed into the rotator cuff tissue by a device that penetrates the full thickness of the cuff tissue; however, placement of a suture through the full thickness of the cuff tissue after a previous suture has already been secured to the bone, will potentially weaken or even disrupt the previous suture fixation. This problem cannot be resolved by moving the point of suture penetration further away from the preceding suture penetration point, as this will result in less secure fixation. One of the principle goals of rotator cuff repair is to recreate the anatomical footprint of the tendon&#39;s attachment via secure fixation and, for the reasons explained, this goal will be compromised by a “tie-as-you-go” method. It will be understood by those skilled in the art that the smaller the tear within the tendon, the less room there will be for safely placing a following suture through the torn tissue of the tendon without disrupting or weakening the prior-located suture(s). 
     As such, by facilitating a “tie/secure-as-you-go” procedure, the above problem of suture management is largely resolved and this is in fact achieved with the use of the tissue fastener devices of the invention, which permit “tie/secure-as-you-go” procedures. Also because the state-of-the-art procedures for the reasons explained, require multiple sutures to be engaged with rotator cuff tissue before anchoring thereof to bone, suture management of untied multiple suture strands is a major technical challenge in state-of-the-art arthroscopic rotator cuff repair. The problems intensify as the number of sutures are placed in position, a maze of sutures often leading to inadvertent tying of incorrect suture pairs, failure to find sutures in the procedure field, inadvertent release of sutures from their anchors and tangling of sutures around instruments and among other sutures and soft tissues. This suture management within the rotator cuff procedure above described and with the aid of the medical devices of the invention is greatly facilitated. 
     Still further, upon completion of a rotator cuff repair as envisaged, there are occasionally areas where the tendon is not adequately tensioned and not adequately laying on bone. For the reasons mentioned above, a surgeon cannot use a state-of-the-art suture passing instrument to augment the repair. However, with the use of the tissue fastener device  2  of the invention, a surgeon will have a simple option of augmenting and thereby to fine tune a repair without risking the existing repair sutures. 
     It is also known for suture passing devices to be used for deploying sutures into the rotator cuff. With the use of these devices there are several steps involved in the process, with each step being exposed to technical difficulties. These steps particularly involve the loading of sutures outside the portal defined by a cannula, grabbing the tendon in the jaws of the suture passing device arthroscopically, deploying the sutures arthroscopically, withdrawing the suture-passing device, and then retrieving the sutures into a portal. Alternately, cannulated suture shuttling and penetrating devices also are commonly used that involve several complex steps. Specifically, first the rotator cuff is pierced with the device. This is technically difficult, and to facilitate the procedure, devices that have various curves and or twists have been designed. Then, typically, a suture or wire (pull through stitch) is advanced through the cannulated shuttling device. This wire or suture is then retrieved into a separate cannula. Then, the suture to be used in the rotator cuff repair is placed through a loop or penetrating device in the pull-through stitch and pulled (shuttled) through the tendon. These complex processes are eliminated with the use of the tissue fastener device  2  of the invention, which affords a surgeon a simple method of attachment of suture to the tendon. 
     Third Set of Exemplary Surgical Procedures 
       FIG. 16  illustrates an alternative surgical procedure utilizing a tissue fastener such as tissue fastener  2  in accordance with the present invention that completely eliminates the use of sutures in any form. In this embodiment, a tissue fastener device has essentially the same basic components of the tissue fastener device  2  shown in  FIGS. 5-7 , including a shank portion  32 , a hook formation  34 , and a hole  36 ′. Instead of threading a suture through the hole  36 ′, a bone anchor  100  is passed through the hole and screwed or otherwise inserted into the bone. The bone anchor  100  may be a simple bone screw with a threaded shaft  101  smaller in diameter than the diameter of the hole  36 ′ in the tissue fastener device  2  and a head  102  with a diameter greater than that of the hole  36 ′. 
     The hole  36 ′ may be counterbored (not shown) so that the head  102  of the screw  100  will be substantially flush with the surface of the shank portion  34  of the tissue fastener device  2 . The screw may be polyaxial. For instance, the hole in the tissue fastener device may be spherical and the screw may have a mating spherical head so that the screw can pivot about the interface between the spherical head and the spherical seat in the hole through a defined cone of freedom. In one embodiment, the spherical head and/or the spherical seat in the hole may have ridges or other formations for interlocking with each other to generate a stronger grip between the screw head and the hole. The ridges may be plastically deformable when the screw is forced down into the seat to provide even stronger gripping there between. 
     In order to even further increase rigidity and help prevent backout of the bone screw  100 , a mechanism to directly fixedly attach the screw  100  to the hole  36  in the tissue fastener device  2  (rather than just trapping the shank  32  of the tissue fastener device  2  between the head  102  of the screw  100  and the bone surface) may be additionally provided. For instance, hole  36 ′ may be internally threaded so that, when screw  100  is screwed into the bone, it also threadedly engages and becomes directly fixed to the tissue fastener device  2 , not only the bone  42 . In a preferred embodiment of this feature, the threads  104  on the screw  100  for engaging the hole  36 ′ are different than the threads  103  on the screw  100  for engaging the bone (since thread formations most suitable for threading into bone are different than thread formations most suitable for mating contact in a pre-threaded hole). In such an embodiment, the proximal portion of the shank of the screw  100  would bear threads  104  adapted for engaging the threads in the hole  36 ′ and the distal portion of the shank of the bone screw  100  would bear threads adapted for engaging bone. 
     The tissue fastener device  2  may be engaged with the soft tissue  40  in the usual fashion as discussed above in connection with  FIG. 9 . 
     Thereafter, a suitable surgical tool can be inserted through a cannula that can guide the tissue fastener to a position such that the hole  36  is positioned above the desired location on the bone for the screw  100  to be inserted. The bone screw  100  is then inserted through a cannula (not shown) into the hole  36  and screwed into the bone using a suitable driver (not shown) in order to attached the tissue fastener  2  directly to the bone without the use of sutures. 
     In an alternate embodiment of the tissue fastener device, the shank may include more than one hole so that the tissue fastener device can attached to the bone using multiple screws, pegs, tacks, or other bone fastening devices. 
     Fourth Set of Exemplary Surgical Procedures 
       FIGS. 17 and 18  illustrate a further arthroscopic procedure for engaging a suture with soft tissue using the tissue fastener device  2  in conjunction with a conventional bone anchor  39 . 
     Insofar as the procedure hereafter described is an arthroscopic procedure, the repair procedure is initiated by locating cannulas  44  (only one shown) in incisions that are positioned so that access is provided to the tendon  40  and the humerus  42  to which the tendon is to be attached, this access particularly accommodating the use of arthroscopic tools. The location of cannulas  44  and normal preparation in relation to a repair is conventional and, as such, is not described further herein. 
     Particularly, within an arthroscopic procedure as envisaged, the first step in the procedure typically involves the formation of a pilot hole  37  in the humerus  42  in a location where sutures must be anchored to the humerus. The pilot hole  37  is formed arthroscopically with the aid of a suitable tool that facilitates this. The pilot hole  37  particularly is formed to receive an anchoring device  39  therein, particularly a device to which sutures can be tied or otherwise secured for effective anchoring of the sutures to the humerus. The mode of location of an anchoring device is variable and is determined by the type of anchoring device involved, it being possible, for example, to locate an anchoring device without the requirement of first forming a drill hole. 
     Each suture  46  (there may be one or more) to be engaged with the tendon  40  and anchored to the anchoring device  39  to be located in the pilot hole  37  is then tied to a separate tissue fastener device  2 , particularly via the hole  36  defined in the body  30  thereof. Thereafter, each body  2  is operatively engaged with an applicator tool that is configured to permit engagement of the tendon  40  by the tissue fastener device  2  via its hook formation  34 , in the configuration as shown in  FIG. 17 . It will be understood that, when so engaged, the suture  46  tied to the device  2  will extend from the person&#39;s body via the cannula  44  through which access to the tendon is provided, the free end of the suture thus being easily “controllable”. 
     With each suture  46  (only one shown) engaged with the tendon  40 , each suture is tied under tension to an anchoring device  39  that is then located in the pilot hole  37  provided therefore. Insofar as this anchoring procedure is already known and insofar as it does not form a part of the present invention, this is not described further herein. The above procedure is performed for each further anchoring device to be used and the sutures to be anchored thereto. 
     Second Set of Exemplary Embodiments 
     A second embodiment of the bone anchor device is shown in  FIGS. 19 and 20 . This bone anchor device is largely similar to the first embodiment shown in  FIGS. 1-4 , except for the manner and mechanism by which the eyelet pin engages the anchor body. Particularly, as in the above noted embodiments, both the anchor main body  210  and the eyelet pin  212  are formed of a metal material of a type already commonly used within the body of a person, e.g., a metal or metal alloy such as titanium, stainless steel and cobaltchrome alloys; a suitable polymeric material that is nonabsorbable such as polyethylene, poly-ether-ether-ketone (PEEK), poly-ether-aryl-ketone (PEAK); a resorbable polymer selected from homopolymers, copolymers and blends of polylactide, polyglycolide, polyparadioxanone, polytrimethylene carbonate or polycaprolactone; or composites of the aforementioned with biocompatible inorganic substances such as carbon, hydroxyapatite, beta tricalcium phosphate, other calcium phosphate ceramics or calcium sulfate. 
     The anchor main body  210  defines an operative leading end  214  and an operative trailing end  216  and a self-tapping thread  218  extending externally along the length thereof from its operative leading end towards its operative trailing end. At its trailing end  216  the body defines a head formation  220 , the head formation being geometrically profiled to permit engagement with a screwdriver-type tool for screwing the body into a bone. The body  210  also defines a receiving formation  222  therein that is in the form of a cylindrical blind bore, the receiving formation  222  being particularly configured to securely receive an eyelet pin  212  therein. 
     The eyelet pin  212  defines a passage  224  therethrough near its proximal end and a longitudinal slot  226  that extends therein from the distal end. The pin thus defines two legs  228  on opposite sides of the slot  226 . The pin  212  is configured to be securely locatable within the receiving formation  222  defined by the anchor main body  210 , at least partially due to an effective friction fit, as in the first embodiment described above in connection with  FIGS. 1-4 . The inherent deformability of the material forming the pin  212  and the configuration of the slot  226  both serve to enhance the required location of the pin within the receiving formation  222  defined by the body  210 . In order to further enhance the location of the pin  212  within the receiving formation  222  defined by the anchor main body  210 , the pin  212  defines a peripheral groove  230  within which an elastic band, preferably an O-ring element  232 , is received. The O-ring may, for instance, be made of silicone. The anchor main body  210  also defines a groove  234  within the receiving formation  222 , the positioning of the grooves  230  and  234  being such that, with the pin inserted into its required operative configuration within the receiving formation  222  of the body  210 , the grooves  230  and  234  will oppose one another, providing for the location of the O-ring element  232  therein, thus serving to further enhance the locking between the body and the pin when the pin is deployed downwardly into its closed position (hereinafter the “closed” position). It will be understood that the resilient elasticity of the O-ring element  232  and the slotted configuration of the pin  212  will permit the insertion of the pin  212  into the receiving formation  222  with the O-ring element effectively assembled into the groove  230 , the O-ring element  232  again expanding when the grooves  230  and  234  oppose one another, as described above. 
     As in the first embodiment of  FIGS. 1-4 , with a suture  46  passing through the passage  224  and by the location of the pin  212  within the receiving formation  222  defined by the body  210 , the segments of the suture extending from the section passing through the passage  224  are effectively gripped between the outer surface of the pin  212  and the inner surface of the passage  222  in the body  210 , thus providing for effective anchoring of the suture, as will be explained in more detail hereafter. In order to prevent suture damage during the location of the pin  212  into the receiving formation  222  of the body  210 , the end of the receiving formation  222  may be flared as shown at  223 . The opposite ends of the passage  224  may be similarly flared. The formation of an effective cutting edge between the pin  212  and the body  210  is thus avoided, when the pin is inserted into the receiving formation  222  with a suture passing through the passage  224 . 
     Third Set of Exemplary Embodiments 
     Referring now to  FIGS. 21 to 25  of the drawings, a third embodiment of a bone anchor device  300  for anchoring a suture engaged with soft tissue to a bone in accordance with the invention includes a substantially cylindrical body  340  (shown in  FIGS. 21-23 ) and an eyelet pin  342  (shown in  FIG. 24 ). Both the anchor main body  340  and the eyelet pin  342  can be formed of materials equivalent to those referred to above. The anchor main body  340  again defines an operative leading (or distal) end  344  and an operative trailing (or proximal) end  346  and a self-tapping thread  348 . At its trailing end  346 , the body defines a geometrically profiled formation  50  that permits engagement with a screwdriver-type tool for screwing the body into a bone. For the purpose described hereafter, the effective diameter of the formation  350  is equal to or smaller than the diameter of the remainder of the anchor main body  340 . The body  340  again defines a receiving formation  352  that is in the form of a cylindrical blind bore, the receiving formation  352 , in this case, defining an enlarged trailing end segment  354 , as illustrated. The receiving formation  352  provides for the secure location therein of the eyelet pin  342 . 
     The eyelet pin  342  again defines a passage  356  therethrough near the proximal end thereof and a longitudinal slot  358  that extends therein from the distal end. The pin thus again defines two legs  360 . The two legs, in this case, have bands  362  of a resiliently deformable material located thereon which, upon the location of the pin  342  in the receiving formation  352 , enhance the secure location of the pin within the receiving formation. 
     With a suture  46  passing through the passage  356  defined by the eyelet pin  342  and with the pin  342  fully inserted in the receiving formation  352  of the anchor main body  340 , it will be appreciated that the suture  46  will take a tortuous path in the bone anchor device, as shown at  335  in  FIG. 25 , which shows the pin  342  disposed in the anchor body  342  in the closed position, particularly, insofar as the passage  356  will be located within the enlarged region  354  of the receiving formation  352 . 
     In relation to the bone anchor devices described above, it must be appreciated that their design may vary in different respects. By way of example and with reference to  FIG. 26  of the drawings, an eyelet pin  363  of a bone anchor device  300 ′ may define surrounding ridges  364  that are operatively located in complementary grooves  365  defined in the receiving formation  366  of the anchor main body  367  of the device, for the location of the pin in the receiving formation. This may be accommodated by the inherent resilient deformability of the material forming the pin  363 . Clearly, the ridges may, alternatively, be defined within the receiving formation of the anchor main body  367  and complementary grooves may be defined within the eyelet pin  363 . Any number of complementary formations may be defined for this purpose, whereas the exact configurations of these formations also are variable. Many other locating arrangements for this purpose also can be envisaged. 
     Fifth Set of Exemplary Surgical Procedures 
     The bone anchor devices  1 ,  200 ,  300 ,  300 ′, described hereinabove may be used in connection with various different procedures that involve the anchoring of soft tissue to bone, which is required in relation to the repair of various different injuries, as described hereafter. This includes any of the surgical procedures described hereinabove such as those described in connection with  FIGS. 8-12  and  13 - 15 . 
     It will be understood that, in relation to the anchor main body  210 , the head formation  220  in the second embodiment of  FIGS. 19 and 20  will protrude from the bone with the anchor main body screwed into a bone, whereas, in relation to the anchor main body  340  in the third embodiment of  FIGS. 21-25 , the entire anchor main body can be screwed into a bone to become effectively embedded within the bone. 
       FIGS. 27 and 28  illustrate a fifth procedure or procedure step envisaged for performing a rotator cuff repair in accordance with the present invention and using the bone anchors of the present invention.  FIGS. 27 and 28  illustrate this procedure utilizing the bone anchor  200  of the second embodiment illustrated in  FIGS. 19 and 20  and provides for the anchor main body  210  to be screwed into the humerus  70  in a desired anchoring location. Prior to being screwed into the humerus, the anchor main body  210  has an eyelet pin  212  partially located therein, the eyelet pin  212  carrying a suture  72  as shown. It must be appreciated in this regard that the eyelet pin and suture also can be so placed immediately after the location of the anchor main body  210 . 
     Following the location of the anchor main body  210  as shown and in order to provide for the required location of a damaged tendon  74  with respect to the humerus  70  with the aid of a suitable arthroscopic passing instrument, one end of the suture is passed through the tendon  74  and then again passed through the passage in the eyelet pin  212 , thus in effect forming a closed loop  76 , whereby the tendon is engaged. By thereafter applying tension to the two end segments of the suture  72 , the tendon  74  is pulled towards the bone anchor device  200  into a required location with respect to the humerus  70  where re-attachment with the humerus is desired, following which the eyelet pin  212  is displaced into its closed configuration in which it is fully inserted into its receiving formation  222  defined by the anchor main body  210  to thereby effectively anchor the suture with respect to the bone anchor device  200 . This position of the tendon  74  with respect to the humerus  70  is illustrated in  FIG. 28 , which also illustrates the loop  76  formed by the suture  72  which permits the tendon to be pulled into its required location as described. With the two ends of the suture  72  effectively gripped between the eyelet pin  212  and the anchor main body  210 , required anchoring of the suture is achieved and the end segments of the suture  72  can then be cut off to provide the configuration shown in  FIG. 28 . It will be understood that, in relation to a particular tendon, two or more bone anchor devices  200  can be utilized, each bone anchor device being associated with the use of a suture as described. It must also be understood that, in relation to each bone anchor device used, two or more sutures may be passed through the passage of the eyelet pin thereof, wherein each suture can be passed through the associated tendon in the manner described. 
     It will be understood that essentially similar procedures can be performed except using the tissue fastener illustrated in  FIGS. 5-7  to attach the suture to the tendon  74 , rather than stitching through the tissue of the tendon. 
     Sixth Set of Exemplary Surgical Procedures 
     With reference to  FIGS. 29 and 30  of the drawings, a sixth procedure or procedure step that is envisaged for performing a rotator cuff repair provides for an anchor main body  210  of a first bone anchor device  200  in accordance with the second embodiment as described in connection with  FIGS. 19 and 20  and an anchor main body  340  of a second bone anchor device  300  in accordance with the third embodiment as described in  FIGS. 21 to 24  to be screwed into the humerus  80  in locations as shown. The anchor main body  210  has an eyelet pin  212  partially located therein in the open position, the eyelet pin  212  having two separate sutures  82  passing through the passage defined by the eyelet pin  212 , the sutures  82  defining loop formations  84  at one of their ends and serving as shuttling sutures as described hereafter. 
     The other anchor main body  340  has an eyelet pin  342  fully inserted therein, the eyelet pin  342  having a suture  86  passing through its passage. The suture  86  thus defines suture segments,  86 . 1  and  86 . 2  respectively that extend from the eyelet pin  342 . 
     With the anchor main bodies  210  and  340  being located as shown, with the aid of a suitable passing instrument, each suture segment  86 . 1  and  86 . 2  is passed through the tendon  88  and then through a loop formation  84  in one of the shuttling sutures  82 . Thereafter, by pulling on the ends of the shuttling sutures  82  remote from the loop formations  84 , the shuttling sutures together with the suture segments  86 . 1  and  86 . 2 , are pulled through the passage in the eyelet pin  212  of bone anchor  200 , thus providing for each suture segment to form a loop that extends from the eyelet pin  342  of bone anchor  300  through the tendon  88  and back to the eyelet pin  212  of the bone anchor  200 . Thereafter, by pulling on the suture segments  86 . 1  and  86 . 2 , the tendon  88  is pulled towards its desired location with respect to the humerus  80  in which it should attach itself to the humerus  80 , following which the eyelet pin  212  is displaced into its closed position, fully inserted in the receiving formation of the anchor main body  210 . Thereby, the suture segments  86 . 1  and  86 . 2  are effectively anchored with respect to the bone anchor device  200 .  FIG. 30  particularly illustrates the operative configuration of the suture  86  with respect to the two bone anchor devices  200  and  300  used and a tendon  88  to be attached to the humerus  80 . It must again be appreciated that further pairs of bone anchor devices  200 ,  300  can be utilized in a similar manner for the attachment of a tendon to a humerus, thus providing a more effective attachment footprint that will ensure the effective attachment of a tendon to a humerus. 
     In alternate embodiments, this surgical technique can be practiced with medial bone anchors of other designs, including conventional designs, than the bone anchor  300  of the present invention. 
     Seventh Set of Exemplary Surgical Procedures 
     As a variation of the above sixth procedure, and as illustrated in  FIGS. 31 and 32 , for the location of the anchor main body  340  in the humerus, it is first displaced through the tendon  88  and then screwed into the humerus  80  in the location shown. By doing so the two segments  86 . 1  and  86 . 2  of the suture  86  are effectively passed through the tendon  88 , as illustrated in  FIG. 31 . The remainder of the procedure is effectively the same as before, thus providing the anchored suture configuration as shown in  FIG. 32 . 
     Eighth Set of Exemplary Surgical Procedures 
       FIGS. 33 to 35  illustrate still further repair procedures in relation to the use of bone anchor devices as above described,  FIG. 33  illustrating a procedure similar to that illustrated in  FIGS. 29 and 30  except insofar as two pairs of bone anchor devices are used and one suture segment of the respective sutures crosses over as illustrated, in order to again create a more effective attachment footprint to provide for the secure attachment of a tendon to a humerus. 
       FIG. 34  also illustrates a cross-over procedure as above envisaged, but in relation to the procedure as illustrated in  FIGS. 27 and 28 , whereas  FIG. 35  illustrates a procedure that involves a combination of the procedures described in  FIGS. 27 and 28  and in  FIGS. 29 and 30 , as is clearly apparent.  FIG. 35  illustrates a dual row fixation method, it being submitted that, in association with the repair of rotator cuff injuries, depending on the nature of individual injuries, particularly suitable repair procedures can be utilized in order to enhance and render most effective the repair of injuries. It will be appreciated that many further variations within the above procedures can be envisaged, a major benefit of the use of the procedures being that the need for suture knotting is completely eliminated, which will, in turn, significantly facilitate general suture management. 
     Fourth Set of Exemplary Embodiments 
       FIG. 36  is a cross-sectional side view of a bone anchor device  400  in the open state in accordance with a fourth embodiment of the present invention.  FIG. 37  is a similar cross-sectional view, except showing the device  400  in the closed state.  FIGS. 38-42  show some of the components of the overall bone anchor device  400  individually (i.e., disembodied from the overall device  400 ) for greater clarity. 
     Bone anchor device  400  in accordance with the fourth embodiment comprises a threaded anchor main body  401  (shown disembodied from the device in  FIG. 38 ) in the nature of a screw or awl bearing threads  425 , which can be screwed into a bone in a desired location as previously described. The anchor main body  401  comprises a central longitudinal bore  418  that is open at the proximal end and closed at the distal (or tip) end. The bore  418  comprises three segments, i.e.,  418   a  at the proximal end,  418   b  in the intermediate portion, and  418   c  at the distal end. Segment  418   a  has the largest internal diameter, section  418   b  has an intermediate diameter, and segment  418   c  has the smallest diameter. The interface between segments  418   a  and  418   b  defines a first shoulder  421  and the interface between segments  418   b  and  418   c  defines a second shoulder  422 . A shaped head  423  is provided at the proximal end of anchor main body  401  for engagement by a driving device such as a screwdriver or other geometrical driver, such as a Torx arrangement. 
     In other embodiments of this (or any of the other anchor main bodies described herein), the threads  425  on the anchor main body may be eliminated or reduced in size or replaced with ridges, striations, or other external formations and the bone anchor can be inserted into the bone by pounding (as in the nature of a nail), instead of screwing. In such embodiments, a hole may be pre-drilled into which the anchor main body  401  is inserted. 
     A central pin  402  extends longitudinally in bore  418 . The central pin  402  has a diameter slightly smaller than the diameter of distal bore segment  418   c  of anchor main body  401  such that it fits within segment  418   c  snugly but freely slidably therein in the longitudinal direction and freely rotatable about its longitudinal axis. In a preferred embodiment of the invention, the bore  418  and the pin  402  are cylindrical so that the pin  402  can rotate about its longitudinal axis relative to the anchor main body, which is a useful feature in many applications, as will be discussed in more detail below. However, in other embodiments, they may have non-cylindrical profiles since it is not required that the elements be rotatable relative to each other. 
     The proximal end  408  of the central pin  402  may be textured as shown to help grip sutures as will be discussed in more detail herein below. The texturing may take any number of forms. In one embodiment as illustrated, it comprises a series of peaks and valleys in the nature of an egg carton type shape. However, in other embodiments, the texturing may comprise parallel ridges, corrugations, serrations, divots, or general roughening of the surface. In yet another embodiment, a bore as shown in phantom at  408   a  in  FIG. 36  may be formed in the central pin  402   a.    
     Next, an eyelet pin  403  (shown separately in  FIG. 39 ) is disposed in the longitudinal bore  418  of the anchor main body  401  over the central pin  402 . Particularly, eyelet pin  403  includes a transverse eyelet  409  intermediate its proximal and distal ends. One or more sutures will pass through the eyelet  409  and be locked in the device during the surgical procedure, as will be described in more detail herein below. Eyelet pin  403  includes a proximal bore  415  proximal of the eyelet  409  and a distal bore  417  distal of the eyelet  409 . In the particular embodiment illustrated in  FIGS. 36 ,  37 , and  39 , the proximal bore is blind to the eyelet  409 , i.e., eyelet  409  and proximal bore  415  are not in communication with each other. However, as will be discussed below, in alternate embodiments, proximal bore  415  may extend completely through to and into communication with eyelet  409 , e.g., as illustrated in  FIG. 44F , discussed further below. The proximal longitudinal bore  415  is for the purpose of accepting a longitudinal member of an impactor tool as will be described in further detail herein below. 
     Distal bore  417  is open to and in communication with the eyelet  409 . The diameter of distal bore  417  is equal to or slightly smaller than the diameter of central pin  402  so as to form an interference fit with the central pin, as will be described in more detail herein below. Thus, when assembled (in either the open position shown in  FIG. 36  and the closed position shown in  FIG. 37 ), the eyelet pin  403  and central pin  402  are not rotatable relative to each other, but the assembly of the eyelet pin and central pin collectively is freely rotatable relative to the anchor body because the central pin is freely rotatable in bore  418 . 
     The distal portion of eyelet pin  403  includes two ramp formations  406  (near the distal end) and  407  (intermediate the distal end and the eyelet  409 ). 
     The proximal portion of the eyelet pin is a breakaway portion that will be removed from the body prior to the end of the surgery. The breakaway portion  410  is defined by a weakened section that can be broken relatively easily. This may be provided by a thinning of the material of the eyelet pin, such as by fabricating a radial notch or V-groove in the material, as illustrated at  413  in  FIGS. 36 and 37 . 
     The eyelet extension portion  410  serves several important functions. For instance, essentially the rest of the bone anchor device  400  other than extension  410  is embedded in and below the bone surface after installation of the bone anchor device in bone and, thus, is extremely difficult for the surgeon to see once installed, particularly in an arthroscopic procedure. However, the breakaway portion  410  of eyelet pin  403  protrudes substantially from the bone and is, therefore, easy to visualize. In one embodiment, at least the extension portion  410  of the eyelet pin  403  is brightly colored to even further enhance its visibility. 
     A locking ring helps retain the eyelet pin  403  in the anchor main body. In the embodiment shown in  FIGS. 36 and 37 , the locking ring  404  is a C-shaped ring (also shown separately in  FIG. 40 ). 
     Locking ring  404  is made of a strong resilient material such as a metal or polymer so that, upon application of sufficient force in the radial direction, it can be spread radially outwardly, or squeezed radially inwardly, to change its diameter and return elastically when the force in the radial direction is removed. The inner and outer surfaces  404   c ,  404   d  of locking ring  404  are conical rather than cylindrical is shape. That is, inner and outer surfaces  404   c ,  404   d  are not parallel to the longitudinal axis  405  of locking ring  404  (i.e., up-down in  FIGS. 26 and 37 ). Thus, a force applied to either surface  404   c  or  404   d  in the longitudinal direction (such as by ramp formations  406  or  407  on eyelet pin  403  hitting the inner surface  404   c  of locking ring  404  as eyelet pin  403  travels longitudinally in bore  418  of anchor main body  401 ) will be converted partially to force in the radial direction. Thus, if either ramp formation  406  or  407  meets the inner surface  404   c  of locking ring  404  with sufficient force, it can cause locking ring to radially expand outwardly, permitting that ramp formation to pass through the locking ring  404 . When the force is removed, locking ring  404  returns elastically to its stress free (or unbiased) state. 
     Locking ring  404  is designed such that the required amount of force to make that happen is greater than could normally be applied accidentally, but that will permit ramp formations  406  and  407  to pass through locking ring by a moderate strike with a mallet on the proximal end of eyelet pin  404  during assembly or during surgery such, as will be described in further detail herein below. 
     An insert  405  is disposed in the proximal segment  418   a  of axial bore  418  in the anchor main body  401 , as seen in  FIGS. 36 and 37 . The insert  405  also is shown separately in  FIG. 41 . Insert  405  is essentially a hollow cylinder having a constant outer diameter equal to or slightly larger than the inner diameter of proximal segment  418   a  or bore  418  in anchor main body  401 , but comprising two sections  431  and  433  of different internal diameter. The distal section  431  has a narrower inner diameter than the proximal segment  433 , thereby forming a shoulder  435  there between. Accordingly, insert  405  forms an interference fit within bore segment  418   a  essentially permanently fixing it in bore segment  418   a  in the position shown in  FIGS. 36 and 37 . 
     The inner diameter of the distal segment  431  of insert  405  is smaller than the largest external diameter of locking ring  404 . The inner diameter of intermediate segment  418   b  of bore  418  in anchor main body  401  is smaller than the smallest outer diameter of locking ring  404 . Accordingly, locking ring  404  is captured in segment  418   a  of bore  418  of anchor main body  401  between shoulder  421  between bore segments  418   a  and  418   b  and the distal end  405   b  of insert  405 . The longitudinal length of insert  405  is selected so that, when insert  405  is fully inserted in bore  418  with its proximal end  405   a  essentially flush with the proximal end of anchor main body  401 , the distance between the distal end  405   b  of insert  405  and shoulder  421  in axial bore  418  is slightly greater than the height of locking ring  404 , thus essentially capturing locking ring  404  in the position as shown in  FIGS. 36 and 37 . 
     The bone anchor device  400  is assembled by first inserting the central pin  402  into bore  418  in the anchor main body  401 . Particularly, it is inserted into the distal bore segment  418   c  of the anchor main body  401 , as previously mentioned. Next, locking ring  404  is inserted into bore  418  where it will sit on shoulder  421 . Next, insert  405  is press fit into proximal section  418   a  of bore  418 , as previously described to capture locking ring  404  between insert  405  and shoulder  421 . 
     Then, eyelet pin  403  is inserted into bore  418 . Specifically, eyelet pin  403  falls readily through proximal bore segment  418   a  until it reaches central pin  402 . whereupon it must be forced further downward over central pin  402  into an interference fit between the central pin  402  and the distal bore  415  of the eyelet pin  403 , In addition, sometime after central pin  402  is in distal bore  415 , ramp formation  406  comes into contact with the inner surface  404   c  of locking ring  404 . Particularly, the largest diameter of ramp formation  406  is larger than the smallest diameter of the inner surface  404   c  of locking ring  404  when locking ring  404  is in its unbiased condition. Only upon application of significant downward force applied to ramp  406  on locking ring  404  will locking ring  403  be forced to expand radially sufficiently to permit ramp  406  to pass through. 
     Accordingly, sufficient force is applied downwardly on eyelet pin  403  to permit ramp formation  406  to pass through locking ring  404  (while simultaneously overcoming the continuing resistance to longitudinal movement of the eyelet pin  403  relative to the central pin  402  due to the aforementioned interference fit between the central pin  402  and the distal bore  415  of the eyelet pin  403 . Once ramp  406  is through, the force is relieved and locking ring  404  returns to its stress-free state. At this point, the eyelet pin is now constrained in anchor main body  401  in the open position by virtue of first ramp formation  406  preventing the, now joined, eyelet pin  403  and central pin  402  from being pulled out proximally and the interference fit between central pin  402  and eyelet pin  403  preventing the joined eyelet pin  403  and central pin  402  from being pushed further into the bore  418  than the point at which the distal end of center pin  402  bottoms out in bore portion  418   c . Accordingly, eyelet pin is axially trapped in anchor main body  401  with no or a very limited range of axial movement. 
     Only when sufficient downward force is again applied to eyelet pin  403  to (1) overcome the resistance to relative axial movement between the center pin  402  and the eyelet pin  403  resulting from the interference fit and (2) cause ramp formation  407  to expand locking ring sufficiently for ramp  407  to pass through locking ring  404  can eyelet pin  403  be disposed into the closed position as shown in  FIG. 37 . 
     The locking ring  404  illustrated in the Figures is exemplary. Other devices, particularly, other elastically deformable rings, can be substituted for the locking ring, such as an elastically deformable closed ring or a split ring (neither shown in the Figures).  FIG. 49 , for example, illustrates another ring structure  700  comprising four crescent elements  701  having grooves within which an O-ring  703  can be inserted into in a radial constraining arrangement. This arrangement  700  will operate essentially in the same manner as the above-described locking ring. 
       FIGS. 71A ,  71 B,  72 A, and  72 B illustrate an alternative embodiment of the anchor device employing a different mechanism for retaining the eyelet pin and central pin within the anchor main body. 
       FIG. 71A  is a cross-sectional side view of the anchor assembly in accordance with this embodiment. In this embodiment, the anchor main body  401 ′ includes a central longitudinal bore  418 ′. This central bore comprises two primary portions, a proximal portion  418   a ′ and a distal portion  418   b ′ separated by a tapered shoulder  421 ′. Bore portion  418   b ′ has a narrowest portion near its proximal end having a diameter d 3  just distal of the shoulder  421 ′ and flares outwardly therefrom in the distal direction to a widest diameter d 5 . Central pin  402 ′ has a uniform diameter d 1  over approximately its proximal half, but the distal half of central pin  402 ′ is tapered outwardly in the distal direction similarly to the taper in the longitudinal bore portion  418   b ′ of the anchor main body  401 ′ to a diameter d 2 , greater than d 1 . The widest diameter of the central pin, d 2  is smaller than the diameter d 3  of the narrowest portion of the longitudinal bore  418 ′ so that the central pin may be inserted into the bore portion  418   b ′ during assembly. 
     The eyelet pin  403 ′ may be largely similar to the previously described eyelet pin  403 , including a transverse eyelet  409 ′, a distal longitudinal bore  417 ′ and a proximal longitudinal bore  415 ′. The diameter d 4  of the distal portion of the eyelet pin is slightly less than the narrowest diameter portion d 3  of the longitudinal bore  418 ′ so that it can fit freely through that narrowest portion of the bore. As in the embodiment of  FIGS. 36-41 , the inner diameter of the distal bore  417 ′ is about equal to or slightly smaller than the diameter of the proximal portion of the central pin  402 ′ so as to form an interference fit therewith so that the central pin and eyelet pin are essentially locked together, just as in the embodiment of  FIGS. 36-41 . 
     However, to deploy the eyelet pin over the flared distal portion of the central pin  402 ′ requires the distal bore  417 ′ of the eyelet pin  403 ′ to deform to fit over the wider, flared distal portion of the eyelet pin. In one embodiment illustrated in  FIG. 72A , which shows the eyelet pin and central pin disembodied from the anchor main body for clarity, the distal portion of the eyelet pin  403 ′ may be formed as a solid hollow cylinder, much like the pin  403  described above in connection with the embodiment of  FIGS. 36-41 . Alternately, as illustrated in  FIG. 72B , the distal portion of the eyelet pin  403 ″ may be formed as a plurality of longitudinal fingers  424 ′ separated by slits  426 ′ so as to more readily allow the distal portion of the eyelet pin to deform around the flared portion of the central pin. Also, the distal portion of the central pin may have a shape other than a straight conical shape (i.e., a circular cross-section). Other options include a diamond-shaped cross-section, a hexagonal cross-section, a Torx-shaped cross-section, etc. Furthermore, at least the distal portion of the eyelet pin also may be formed in different shapes, including mating shapes to the shape of the central pin. Yet further, the eyelet pin may be formed of a material particularly adapted for deforming as needed to fit over the flared portion of the central pin. Such materials include various deformable polymers and memory PEEK materials that allow the distal end of the eyelet pin to open to a predetermined shape. 
       FIG. 71B  shows the eyelet pin after it has been deployed into the closed position. As can be seen, the distal bore  417 ′ of the eyelet pin  403 ′ has deformed to fit around the flared distal portion of the central pin  402 ′. The eyelet pin and the central pin are still in an interference fit, although perhaps an even stronger interference fit than when the eyelet pin is in the open position before it has been substantially deformed. Furthermore, with the eyelet pin in the closed position so that the distal portion of the eyelet pin is flared radially outwardly around the distal portion of the central pin, the combination of the eyelet pin and central pin can no longer be withdrawn from the flared distal segment  418   b ′ of the longitudinal bore  418 ′ of the main anchor body  401 ′. More particularly, the distal portion of the eyelet pin is now wider than the narrowest diameter d 3  of the longitudinal bore  418 ′ and thus can no longer fit back through it. 
     At this point, the central pin and the eyelet pin are now trapped in the longitudinal bore  418 ′ of the main anchor body with the eyelet pin in the closed position. 
       FIGS. 71C-71F  illustrate another embodiment of the central and eyelet pins. Referring first to  FIG. 71C , which shows an exploded view of the eyelet pin  403 ′″, central pin  402 ″, and anchor body  401 ″, in this embodiment, the eyelet pin  403 ′″ has fingers  425 ″ similarly to the embodiment of  FIG. 72B . However, in addition, the distal ends of the fingers  425 ″ include radially outwardly extending ramped catches  437 . Furthermore, the fingers  425 ″ are flexible so that they can bend radially inwardly in the proximal to distal direction. The central pin  402 ″ is flared similarly to central pin  402 ′ of  FIGS. 72A and 72B , except that only a much shorter, distal-most portion  438  of the central pin  402 ″ is flared. The middle  440  of the length of the central pin has a diameter that is substantially constant and is smaller than the inner diameter of the fingers  425 ″ so that the fingers  425 ″ may flex inwardly when they are longitudinally coextensive with the middle  440  of the central pin  402 ″. Features  442  are provided near the proximal end of the central pin to engage the inner wall of the distal bore of the eyelet pin  403 ′″ so that the central pin and the eyelet pin are frictionally engaged. Features  442  are a set of flats around the diameter of the central pin, the edges of which define a circle slightly larger than the inner diameter of the distal bore of the eyelet pin. The edges provide sufficient friction to hold the central pin and eyelet pin longitudinally fixed relative to each other under light forces, but allow the eyelet pin to be pushed distally over the central pin from the open position to the closed position as previously described. The flare  438  at the end of the central pin  402 ′ has a diameter substantially equal to the inner diameter of the fingers  425 ″ in the unbiased state. Thus, until the eyelet pin  402 ″ is pushed down sufficiently for the distal ends of the fingers  425 ″ to become longitudinally coextensive with the flare  438 , the fingers  425 ″ can bend radially inwardly. However, when the fingers  425 ″ become longitudinally coextensive with the flare  438  of the central pin  402 ″, the fingers can no longer bend radially inwardly because the flare  438  is backing the fingers and preventing them from being bent inwardly. 
       FIGS. 71D ,  71 E, and  71 F show the assembled anchor main body  401 ″, central pin  402 ″, and eyelet pin  403 ′″ in three stages of relative position, respectively, to illustrate operation of this embodiment. The three stages are (1) during assembly ( FIG. 71D ), (2) in the open position ( FIGS. 71E ), and (3) in the closed/suture-locking position ( FIG. 71F ). 
     As shown, the anchor main body  401 ″ includes two shoulders  439   a  and  439   b  that are narrower than the outer diameter defined by the catches  437  at the ends of the fingers  425 ″ of the eyelet pin  403 ′″. The fingers  425 ″ will bend inwardly as needed to allow the frustoconical distal surfaces  437   a  of the catches  437  to ramp through the shoulders  439   a ,  439   b  in the distal direction, the engagement of the frustoconical surfaces  437   a  with the shoulders  439   a  or  439   b  converting longitudinal movement of the eyelet pin relative to the shoulders partially into radially inward force on the fingers. However, once the catches  437  pass through a shoulder  439   a  or  439   b , they cannot pass back through in the distal direction very easily. Specifically, even if the fingers  425 ″ are not yet backed up by the flare so that the fingers are capable of flexing inwardly under force, the proximal surface  437   b  of catches  437  is shaped to catch on the shoulders  439   a ,  439   b  to resist the eyelet pin  403 ′″ being backed out proximally of the anchor main body  401 ″ past where the catches  437  engage either shoulder  439   a ,  439   b.    
     Thus, during assembly as shown in  FIG. 71D , the eyelet pin starts out with the catches  437  proximal of the first shoulder  439   a . However, once the eyelet pin  403 ′″ is pushed down so that the catches  437  pass the first shoulder  439   a , as illustrated in  FIG. 71E , the eyelet pin  403 ′″ can no longer be easily withdrawn from the anchor main body  401 ″ (at least under the relatively minimal forces to which it might be subject during assembly and delivery to the surgeon). The position shown in  FIG. 71E  is the open position in which the device is delivered to the surgical site. The eyelet pin  403 ′″ is in the open position so that the eyelet is free and sutures may be passed through it. However, the eyelet pin cannot be removed from the anchor main body  401 ″ without the application of significant force to overcome the engagement of the proximal faces  437   b  of the catches  437  against the distal face of the shoulder  439   a.    
     Next, to deploy the eyelet pin  403 ′″ into the closed position, in which the sutures in the eyelet are trapped as previously described, the eyelet pin  403 ′″ is pushed down until the catches  437  pass the second shoulder  439   b . When the eyelet pin  403 ′″ bottoms out on the bottom of the aperture in the anchor main body  401 ″, the ends of the fingers  425 ″ bearing the catches  437  are coextensive with the flare  438  of the central pin  402 ″. The fingers  425 ″ can no longer bend radially inwardly under virtually any circumstances because they now are backed up by the flared portion  438  of the central pin  402 ″. Thus, the eyelet pin  403 ′″ is now very difficult to pull out of the closed position, even under the large forces that it might be subject to from the sutures locked in the eyelet during patient recovery. The central pin and eyelet pin, as a unit, can move distally slightly from the position shown in  FIG. 71F  (by whatever vertical tolerance is provided between the second ramp  439   b  and the catches  437 ). Note, however, that the large forces that might be applied on the eyelet pin from the sutures locked in it are forces acting between the eyelet pin and central pin as a unit, on the one hand, against the anchor main body, on the other hand. There is essentially no force exerted between the eyelet pin and the central pin that could cause the eyelet pin to slide relative to the central pin, and certainly no force that can overcome the aforementioned frictional engagement between features  442  on the central pin and the inner wall of the distal bore of the eyelet pin. Thus, there is essentially no possibility of the eyelet pin moving relative to the central pin (e.g., no possibility that the fingers  425 ″ sliding off of the flare  438  and no longer being backed up by the flare). 
     These embodiments of  FIGS. 71A-71F  are simpler than the embodiments of  FIGS. 36-41  in some ways. Particularly, the ramps  406  and  407  on the eyelet pin, the C ring  404 , and the insert  405  are eliminated. In the embodiments of  FIGS. 71A and 71B , for instance, in the open position, the central pin and eyelet pin are not trapped within the anchor main body and can be freely removed prior to deployment into the closed position. Alternately, the central and eyelet pins can be retained in the anchor main body by any reasonable additional mechanism. One mechanism for doing so that utilizes portions of an implantation tool supplied with the anchor assembly is discussed in detail below in connection with  FIGS. 73A-76D  below. 
     Exemplary Embodiments of a Driving Tool 
       FIG. 45  shows a perspective view of an exemplary bone anchor driver tool  500 . It comprises a cannula  503  defining an internal bore  507  and a handle  501  coupled to the proximal end of the cannula, with the proximal end  507   a  of the bore  507  being open to and in communication with the hollow interior of the handle  501 . 
     As will be described in further detail immediately below, the ends of a suture shuttling mechanism, such as a wire or suture loop  411  or a long suture with a loop at each end threaded through the eyelet of the eyelet pin of a bone anchor device of the present invention, may run up the cannula  503  of the driver tool and extend into the hollow handle. The ends of the suture shuttling wire (or suture) may be wrapped around two pins  506  inside of the handle  503  for stowage and safe keeping prior to and during surgery. The handle can include a cap  509  to close off the handle if desired for better containment of sutures or suture shuttling mechanism  411 , as will be described in detail further below. The bore is also open at recess  507   b  to the distal end of the cannula  507 . The recess  507   b  at the distal end of the cannula is matingly shaped to engage the shaped head  423  of the anchor main body  401  of the bone anchor device so as to impart rotation to the anchor main body  401 . As shown, when the driver  500  is engaged with the head of the anchor main body  401  of the assembled bone anchor device  400 , the proximal end of the eyelet pin  403  extends within the cannula  507  of the driver  500 . Preferably, the recess  507   b  is fashioned with gripping means, such as a slight interference fit over part of the mating surfaces of head  423  and recess  507   b , so as to temporarily grip the head  423  of the anchor main body and hold it firmly so that the bone anchor device will not fall out of the driver unintentionally, but which can be released with moderate force once bone anchor  400  has been surgically located. 
     Ninth Set of Exemplary Surgical Procedures 
     The bone anchor device of  FIGS. 36-41  can be used in surgical procedures for attaching soft tissue to bone such as those described herein above in connection with  FIGS. 8-12 ,  13 - 15 , and  16 . 
     In fact, the various bone anchor and tissue fastener devices disclosed herein may be used in any number of surgical procedures, including those specifically described herein. In some such procedures, it may be desirable to provide a suture shuttle mechanism directly associated with the bone anchor device for shuttling sutures from the tissue fastener device or tissue (if no tissue fastener device is used) to the bone anchor device and, particularly, through the eyelet  409 . In accordance with such embodiments, a shuttling mechanism comprising a flexible elongated member such as aforementioned wire loop  411  may be provided as shown in  FIG. 36  passing through the eyelet  409 . Wire loop  411  may be considered to comprise three segments, namely, opposing curved ends  411   a  and  411   b , which are joined by linear segment  411   c . Sutures may be inserted through one end of the loop, such as end  411   b  by a suitable instrument. The other end of the loop  411   a  may be pulled on to draw the loop  411 , along with the shuttled sutures, through the eyelet  409 . For instance, in one particular embodiment, the bone anchor device  400  is delivered to the surgeon already mounted on the driver tool  500 . The loop  411  is long enough so that, with the center of the loop passing through the eyelet  409  of the eyelet pin  403  of the bone anchor device, both ends of the loop can extend up the entire length of the cannula  507  of the driver tool  500  and extending from the proximal end  507   a  of the cannula  507  into the handle  501 , as shown in  FIG. 45  illustrating the exemplary driver tool  500 . Initially, the ends of the loop  411  may be wrapped around the two pins  506  for safe keeping within the interior of the handle. At the appropriate point in the surgical procedure, the wire ends can be unwrapped from the pins  506  so that both ends can be removed from inside the handle  503  of the tool  500  and may be manipulated manually by the surgeon externally of the patient. Having both ends of the loop extending from the driver tool provides several advantages. First, it can be used to shuttle sutures through the eyelet in either direction. Second, it helps prevent accidental deployment of one or both ends of the loop out of the instrument  500  and into the deployed position illustrated in  FIG. 36 . Particularly, if one or both ends of the loop  411  are disposed near the bottom of the tool  500 , then a slight withdrawal of the tool from the bone anchor could release the end of the loop from the cannula. With both ends of the loop extending from the proximal end of the tool  500 , this is much less likely. In addition, the surgeon can manually hold on to both ends,  411   a  and  411   b , of the loop  411  in order to prevent one or both ends from being pulled through accidentally. 
     In any event, in an exemplary procedure, the surgeon would pull on one end of the loop, e.g., end  411   a , until the other end  411   b  is released from the distal recess  507   b  of the cannula  507  of the tool  500  and into the deployed state. Then, the surgeon would thread the suture(s)-to-be-shuttled through the eyelet  409  of the bone anchor device through the deployed end  411   b . After the sutures have been threaded through end  411   b , the surgeon would merely need to grasp end  411   a  with his hand and pull so as to pull end  411   b  through the eyelet  409  and up through the cannula  507  until the end  411   b  of the loop  411  comes completely through the cannula  507 , carrying the suture(s) with it. The surgeon can then disengage the suture(s) from the loop and manipulate the suture(s) directly, e.g., so as to pull the required tension on them before locking the eyelet in the closed position and cutting the free ends of the sutures. 
     The shuttling mechanism  411  may be made of thin, flexible wire. However, in alternate embodiments, it may be fabricated of any string or filament and, in fact, may be formed of suture itself. In an even further embodiment of the invention, the suture shuttle  411  need not be a closed loop. For example, the shuttling mechanism might be comprised of a length of suture folded in half, wherein the fold at the midpoint of the suture comprises the distal end  411   b  of the shuttling mechanism  411  and the two ends of the suture comprise the proximal end of the suture shuttle. To assist with shuttling, small loops may be formed in the ends of the suture (or other filament), such as illustrated by the suture shuttle shown in  FIG. 45 . 
     The bone anchor device  400 , including the anchor main body  401 , the central pin  402 , the eyelet pin  403 , the locking ring  404 , and the insert  405 , is delivered to the surgeon in the assembled, open state as shown in  FIG. 36 . During surgery, the surgeon will install the device  400  in bone by screwing it into a bone using a suitable driving device engaged with the head  423 , such as driver tool  500  described herein above in connection with  FIG. 45 . Note that one of the beneficial features of the present invention is that, since the eyelet pin/central pin assembly is freely rotatable inside the anchor main body, there is relatively less need to worry about the rotational alignment of the anchor main body  401  when it is being screwed into the bone as compared to conventional suture anchors where the eyelet orientation is fixed. It can be screwed in to any rotational position because the eyelet pin  403  is freely rotatable therein to align the eyelet  409  to face in the desired direction (i.e., in the direction from which the sutures will enter the device  400 ). 
     Once installed, the surgeon will shuttle sutures through the eyelet of  409  in the eyelet pin  403  either using a shuttling mechanism such as the wire shuttling device  411  or another device so that one or more sutures pass through eyelet  409 . Then, the surgeon will place an impactor tool into the proximal bore  415  in the extension portion  410  of eyelet pin  403 . In an arthroscopic procedure, this would be done through a cannula. Then, while the surgeon is tensioning sutures acting on the tissue to locate the tissue in an appropriate anatomical position, sufficient force would be applied to the proximal end of the impactor tool, such as by hitting it with a mallet or using it in conjunction with a spring-loaded or pneumatic impacting device to pound the eyelet pin  403  with sufficient force to cause the second ramp formation  407  to spread apart locking ring  404  allowing it to pass through so that the eyelet pin  403  slides down over the central pin  402  into the closed position as shown in  FIG. 37 . Particularly, after ramp  407  passes locking ring  404 , the interference fit between eyelet pin  403  and central pin  402  lock the two pieces  402 ,  403  together in the closed position. 
     As the eyelet pin  403  is driven down into the closed position, the suture(s)  46  passing through the eyelet at  409  gets trapped in at least one of three locations. First, as seen in  FIG. 37 , suture(s) may be crushed between the roof  414  of the eyelet  409  and the proximal end  408  of the central pin  402 . Surgical sutures are highly compressible and deformable without breakage and the design of the interface between proximal end  408  of central pin  402  and roof  414  of the eyelet  409  accommodates varying suture diameters and numbers of sutures. Therefore, the length of central pin  402  should be selected relative to eyelet pin  403  so that the spacing between the roof  414  of eyelet  409  and the proximal end  408  of central pin  402 , when in the closed position, is between zero and a full suture diameter, and preferably between about ⅛ and ¼ of a suture diameter wherein the locked, closed position. The features (e.g., roughening, peaks and valleys, serrations) at the proximal end  408  of the central pin  402  help better grip the sutures. 
     In addition, depending on the diameter of the central pin  402  relative to the cross section of the eyelet pin (i.e., the area in the direction transverse to the direction of the passage through the eyelet between its ends  409   a  and  409   b ), it is possible for sutures to become trapped between the radial circumferential surface of the central pin  402  and the side walls of the eyelet. These locations for trapping sutures  46  can be seen, for instance, in  FIG. 44B , which will be discussed further below. Particularly, if the diameter of the central pin is smaller than the cross section of the eyelet  409  by less than the thickness of two sutures (and is centrally located in the eyelet in the direction transverse the passage and perpendicular to the longitudinal axis, i.e., in and out of the page in  FIG. 37  or left and right in  FIG. 44B ), any sutures that do not become trapped between the proximal end  408  of the central pin  402  and the roof  414  of the eyelet  409  will be compressed and therefore, securely held between the side of the central pin and the side walls of the eyelet. 
     In addition, the suture(s) take on a tortuous shape, such as the W shaped illustrated in  FIG. 37 , thus providing even greater resistance to being pulled free of the bone anchor device  400 . 
     In one embodiment of the invention, the features are small enough and deep enough so that they individually bore into the suture and split the fibers of the suture to provide an even stronger grip. 
     In addition, the suture is crushed between the surface  416  of eyelet pin  403  and the surface of the inner surface of the distal segment  433  of insert  405  at the transverse ends  409   a ,  409   b  of the eyelet  409 . Specifically, the outer surface  416  of the eyelet pin  403  just above the eyelet  409  has a diameter relative to the inner diameter of the proximal segment  433  of insert  405  such that the clearance between the two surfaces is less than the width of the suture. The clearance preferably also may be somewhere between zero and ½ of the diameter of the suture, and more preferably somewhere between ⅛ and ¼ the diameter of the suture. 
     Note that the eyelet  409  need not even be completely within the receiving formation for there to be significant capturing of the suture. Specifically, even if the eyelet is only partially within the receiving formation in the longitudinal direction when in the closed position, the suture will be compressed between the roof  414  of the eyelet pin and the proximal end of the main anchor body as long as the distance (or clearance) between the roof  414  of the eyelet pin and the proximal end of the main anchor body in the longitudinal direction is less than a width of a suture (and those two surfaces are not too far from each other in the radial (or transverse) direction. 
     In alternate embodiments, the central pin  402  need not compress the suture against the roof of the eyelet at all, there being sufficient crushing and fixing of the suture in the other two locations in the lateral space between the inner diameter of the proximal portion  433  of the insert  405  and the surface  416  of eyelet pin  403 . 
     In yet other embodiments, the roof  414  of the eyelet pin  403  may also be configured to help grip the suture. For instance, it may be provided with mating features to the features on the proximal end  408  of the central pin  402 . Alternately, the roof  414  may have different features, such as roughening, serrations, corrugations, ridges, etc. In even further embodiments, the proximal end  408  of the central pin  402  and the roof  414  of the eyelet pin  402  may simply have mating shapes such as a V-shaped groove and a V-shaped protrusion or a ball and socket. 
     In yet other embodiments, a plug or insert may be affixed to the roof of the eyelet  409  to provide better gripping. Such a plug or insert may have some of the aforementioned features. In other embodiments, the insert may comprise a high friction material, such as silicone having a high frictional coefficient or any combinations of any of the above-noted features. It may also be fabricated from a dissimilar metal from the remainder of the eyelet pin  403 . In yet other embodiments, it may comprise a rubber bumper or a leaf spring. 
     In a preferred embodiment of the invention, the proximal end of insert  405  is rounded over or flared, as shown by reference  428  so as to eliminate any sharp edges from contacting the suture and possibly causing it to tear or break. 
     Exemplary Embodiments of Impactor Tool 
       FIGS. 46-48  show an exemplary impactor tool  600  that can be used in connection with the bone anchor device  400  in the procedure described above.  FIG. 46  shows the entire tool.  FIG. 47  shows a close up view of the proximal portion of the tool.  FIG. 48  shows a close up view of the distal portion of the tool. Tool  600  comprises an elongated tube  605  having an internal through bore  606 . The opening  629  at the distal end of the tube (best seen in  FIG. 48 ) is sized to snugly accept the eyelet pin  403  therein, but not the anchor main body  401 , as shown. A handle  603  having a bore  613  coaxial with the bore  606  of tube  605  is mounted to the proximal end of tube  605 . Disposed inside the handle and tube is a rod  619  that is spring loaded by a spring  611  constrained in handle  603 . The spring has light force so as to keep the proximal end  607  of the rod  619  extending completely through the handle  603  so that the proximal end  607  of is exposed such that it can be hit with a mallet or other impacting device. A block  615  is fixedly attached to the rod  619  near the proximal end  607 , but trapped within the handle  603 . Block  615  provides a stop for the spring  611 , which is trapped between the block  615  and the distal end  617  of the handle  603 . The spring  611  and block  615 , when unbiased, maintain rod  619  in the shown position. Thus, striking end  607  of rod  619  drives the rod  619  down through the handle  603  and tube  605 . Although not shown, an enlarged, more stable striking surface for the mallet may be provided either integral with proximal end  607  of rod  619  or as a separate piece that slidably fits over proximal end  607  of rod  619 . The enlarged striking surface may be metal, plastic, or any other suitable material. 
     The distal end of the rod  619 , as best seen in  FIG. 48 , includes a narrowed diameter portion  621  and an even smaller diameter portion (or pin)  623  at the distal end. Portions  623  and  621  are designed so that pin  623  will slidably but snugly fit within the proximal bore  415  of the eyelet pin  403  and the shoulder  624  between pin  623  and narrowed portion  621  will butt up against the proximal end of the eyelet pin  403  when spring  611  is sufficiently compressed. However, in the unbiased condition, as shown in  FIGS. 46-48 , pin  623  is not engaged in proximal bore  410  of eyelet pin  403 , but is coaxial with but slightly spaced from bore  410 . The aforementioned spring  611  maintains the rod in this spaced position from the bone anchor device. A bumper (or ring)  631 , comprised, for instance, of silicone, is attached to the distal end of tube  605  having a hole  632  aligned coaxially with hole  629  in the end of tube  605 . However, in other embodiments, pin  623  may be disposed in bore  410  with the shoulder  624  resting against the proximal end of the eyelet pin  403 . 
     In operation, when it is time to drive the eyelet pin  403  from the open position illustrated in  FIG. 36  to the closed position illustrated in  FIG. 37 , impactor tool  600  is slipped over the bone anchor device  400  as shown in  FIG. 48 . Particularly, bumper  631  is slid over the extension portion  410  of the eyelet pin  403  until it butts up against the head  423  of the anchor main body  401  of the bone anchor device  400 . Any sutures (not shown in  FIG. 48 ) passing through eyelet  409  in eyelet pin  403  would be temporarily held between the head  403  of the anchor main body  400  and the bottom of the bumper  631 . Since the bumper is soft, the sutures would be able to slide, upon being pulled by the surgeon between the head  423  and the bumper  631 . 
     In use, after positioning the impactor tool over the eyelet pin extension portion  410  as shown in  FIG. 48 , the surgeon will grab the end of the suture or sutures through another cannula and pull to the desired tension, drawing the tissue into the desired position relative to the bone. The surgeon can then push the impactor tool  600  down on the top of the anchor main body  401  with some additional force, to hold the sutures in this tensioned state between the bottom of the bumper  631  and the top of the anchor main body  401 . The surgeon can then let go of the sutures and the interaction between the bumper and the top of the anchor main body  403  will hold the sutures in this tensioned position, without damaging the sutures, until the surgeon can strike the impactor tool  600 , causing the eyelet pin  403  to be driven downwardly into the closed position in which the sutures will be locked in the bone anchor device  400 . 
     Specifically, when the surgeon strikes the proximal end  607  of the impactor tool  600 , pin  623  descends into bore  415  and drives eyelet pin  403  down into anchor main body  401  to the closed position shown in  FIG. 37 . Particularly, the force of the impact being sufficient to force the second ramp formation  407  through locking ring  404  and to overcome the interference fit between central pin  402  and eyelet pin and distal bore  418  of eyelet pin  403 ). When ramp formation  407  passes distal surface  404   a  of locking ring  404 , locking ring  404  returns elastically to its stress-free state against shaft  419  of eyelet pin  403 . 
     Preferably, the diameter of the pin  623  is slightly larger than the diameter of the proximal bore  415  of the eyelet pin such that the pin  623  forms an interference fit inside the bore  415  at this time. Preferably, the interference fit is relatively weak so that the eyelet pin  403  can be removed from the impactor tool  600  at a later time. 
     When the eyelet pin  403  is in the open position, the V-groove  413  defining the breakaway portion  410  of the eyelet pin is preferably proximal to the bumper  631 , as shown in  FIG. 48 . Accordingly, the soft bumper  631  and distal tip of cannula  605  helps unload the force of the impact from the V-groove  413  so as to help prevent it from accidentally breaking prematurely before or during impact. 
     After the eyelet pin  403  is driven down into the closed position, the impactor tool  600  is then used to break off the breakaway portion  410  of the eyelet pin  403 . This is achieved by rocking the impactor tool (and the cannula within which it is inserted in an arthroscopic procedure) back and forth so that it pivots about the bumper  631  engaged with the top of the anchor main body  401 . Particularly, when eyelet pin  403  is in the closed position, the V-groove  413  in the eyelet pin  403  is essentially even with the top of the anchor main body  401 , and thus with the bottom of the bumper  631 . The bumper permits the impactor tool  600  to be rocked back and forth so that the V-groove can be broken without metal to metal contact between the impactor tool  600  and the anchor main body  400 . Once broken, the breakaway portion of the eyelet pin will stay inside the impactor tool because of the weak interference fit between the pin  623  at the end of the rod  619  of the impactor tool  600  and the proximal bore  415  of the eyelet pin. Alternately or additionally, the hole  632  defined by the ring-shaped bumper may be designed to be slightly smaller than the diameter of the extension portion  410  of the eyelet pin so that the bumper must slightly deform radially outwardly when it is slipped over the extension  410  providing a tight, but still slidable fit with the extension  410 . This would provide an alternative or additional means of retaining the breakaway portion  410  of eyelet pin  403  inside the impactor tool  600 . The impactor tool  600  can then be removed with the breakaway portion  410  contained therein. 
     In other envisioned embodiments of the invention, a tool that is capable of delivering a precisely controlled striking force may be used instead of a simple mallet. The tool would be adapted to fit over the proximal end  607  of the rod  619  and to deliver a blow along the longitudinal axis of the rod  619 . For instance, Applicants envision a spring-loaded tool, wherein the spring loading is released by a small tap of a mallet, the spring selected and pre-loaded to deliver the exact amount of force desired over the exact travel distance desired. This force should be sufficient to push ramp formation  406  or  407  through locking ring  404  as previously described, but not so much as to injure the bone. In other embodiments, the spring may be released by a trigger mechanism instead of a mallet. 
     Fifth Set of Exemplary Embodiments 
       FIGS. 42 and 43  are cross-sectional views illustrating an alternative embodiment  400 ′ to the bone anchor device  400  shown in  FIGS. 36-41 .  FIG. 42  shows the bone anchor device  400 ′ in the open position, while  FIG. 43  shows it in the closed position. The device  400 ′ is largely similar to device  400  shown in  FIGS. 36-41 . However, it includes two O-rings  443  and  441  that assist with suture management. Particularly, in this embodiment, the insert  405 ′ is slightly modified from the insert  405  of  FIGS. 36 ,  37  and  41 . Particularly, it includes a groove  444  near its proximal end  405 ′ within which a silicone or other resilient material O-ring  443  sits. In a similar manner, eyelet pin  403 ′ also is adapted to have another groove  446  for accepting another O-ring  441  positioned just above the eyelet  409 . As can be seen in  FIG. 43 , when in the closed position, O-rings  441  and  443  meet and press against each other near the top of the anchor main body  401 , precisely where the suture  46  passes through the bone anchor device  400   a . The soft material of the O-rings  441  and  443  grips the suture tightly and also prevents the suture from contacting metal at this juncture, thereby helping assure that the sutures are not damaged or broken during or after the eyelet pin is driven into the closed position. The O-rings may be formed of high friction silicone or any other reasonably resilient material. 
     In yet other embodiments of the invention, other features similar in shape and position to the O-rings  441  and  443  may be provided. Those features may be formed of materials other than the material of the eyelet pin  403  and/or insert  405 . Alternately, the features may be formed directly into the eyelet pin  403 ′ and/or insert  405 ′. The features should have rounded non-sharp shapes that help grip the suture without damaging it. 
     Sixth Set of Exemplary Embodiments 
       FIGS. 44A-44F  illustrate further embodiments of the invention. For sake of clarity, only the eyelet pin  403  and the central pin  402  are shown in each of  FIGS. 44A-44E . However, it should be understood that these components are disposed in the anchor main body  401  with the other elements, such as locking ring  404  and insert  405 , but they are not shown in these Figures in order not to obfuscate the features being particularly illustrated in these Figures. The angle of view in  FIGS. 44A-44D  is rotated 90° from the angle of view in  FIGS. 36 and 37 . 
       FIGS. 44A and 44B  illustrate a first alternate embodiment of the bone anchor device  400  in which a hollow cylinder  901  is disposed in the eyelet  409 . The hollow cylinder  901  is formed of a thin-walled deformable material, such as metal. In one embodiment, the material is plastically deformable. However, if it also could be elastically deformable. In the illustrated embodiment, the hollow cylinder  901  is circular and the eyelet  409  is square with the hollow cylinder  901  sized to have a diameter equal to the transverse cross-section of the eyelet  409 . Therefore, the hollow cylinder  901  contacts the sides of the eyelet at two locations spaced 180° around the hollow cylinder  901 . However, in other embodiments, the eyelet could be square so as to contact the eyelet at four locations spaced at 90° intervals around the hollow cylinder. According to even further embodiments, the hollow cylinder could be oval (and may or may not contact the eyelet at four locations spaced at 90° intervals around the hollow cylinder). 
     The sutures  46  that pass through the eyelet  409  pass through the middle of the hollow cylinder  901 . 
     Referring now to  FIG. 44B , which shows the condition of the components when in the closed position, when the eyelet pin  403  is driven down so that central pin  402  enters the eyelet  409  as previously described, it impinges upon the hollow cylinder  901 , deforming it into the shape shown in  FIG. 44B . As can be seen, the eyelet  409 , hollow cylinder  901 , and central pin  402  are sized relative to each other such that the sutures  46  are crushed by the hollow cylinder  901 . In other words, the clearance between the central pin  402  and the sides of the eyelet  409  is less than the diameter of the suture such that the suture gets fixedly trapped or compressed. One or more sutures also may get fixedly trapped in between the proximal end  408  of the central pin  402  and the roof  414  of the eyelet  409 . 
     This configuration may provide stronger gripping of the sutures. 
       FIGS. 44C ,  44 D, and  44 E illustrate another alternate embodiment involving a modified cylinder  909 .  FIG. 44C  shows this configuration in the open state and  FIG. 44D  shows it in the closed state.  FIG. 44E  shows a perspective view of the cylinder  909  disembodied from the device for sake of clarity. These Figures illustrate two alternate features relative to the device shown in  FIGS. 44A and 44B  that can be incorporated individually or in combination into the device. 
     First, ring  909  has a hole  911  and optionally a second hole  912  formed therein coaxial with each other, and the ring  909  is inserted into the eyelet with the holes coaxially aligned with the distal bore  417  of the eyelet pin  403 . Second, an opening  419  through which the central pin  402  can pass may exist in the roof or top wall  414  of the eyelet  409 . Alternately, the proximal bore  415  may simply extend all the way to and in communication with the eyelet, thereby providing the opening in the top wall  414  of the eyelet. The holes  911 ,  912  are smaller than the central pin  402  such that the central pin cannot pass through eyelet without also deforming the holes  911 ,  912  as well as the ring  909  itself. 
     As shown in  FIG. 44D , in this embodiment, when the central pin  402  is driven through the eyelet  409 , it punches through the bottom hole  911 , thereby deforming the cylinder  909  as shown and capturing the sutures inside the crushed ring  909 . In addition, if an opening  419  is provided in the top wall  414  of the eyelet and/or a second hole  912  is provided in the ring  909 , the central pin may punch through the top hole  912  and/or the opening  419 . As in the embodiment of  FIGS. 44A and 44B , the sutures become fixedly trapped above the proximal end  408  of the central pin in the ring  909  and/or in opening  419 . In the embodiment of  FIGS. 44C and 44D , at least those sutures that are located in opening  419  of the eyelet pin  403  take on an even more tortuous path, thereby providing even greater gripping of the sutures in the bone anchor device. 
       FIG. 44F  shows an even further embodiment of the invention in which the proximal bore  415 ′ of the eyelet pin  403 ″ extends completely through and is in communication with the eyelet  409  such that there is a bore running continuously through the eyelet pin from the distal end, through the eyelet, and to the proximal end of the eyelet pin  403 ″. In this embodiment, there is no surface in the roof of the eyelet  409  that the proximal end  408  of the central pin  402  can crush sutures up against. Nevertheless, sutures that do end up above the central pin  402 , rather than on the sides thereof, take on a particularly tortuous path, and therefore are still tightly gripped in the bone anchor device. 
     The various different hollow cylinders  901 ,  909  and the various different configurations of the bore  415  and  417  in the eyelet pin  403  can be combined with each other in various permutations. For example the hollow cylinder  901  need not be a continuous ring and may have a circumferential gap (e.g., a split hollow cylinder) such as a rolled piece of thin metal or a roll pin. 
     In other embodiments, as already noted, the hollow cylinder need not be perfectly cylindrical, but can have an oblong or oval cross-section. In such embodiments, the eyelet can be rectangular so as to match the dimensions of an oval hollow cylinder (i.e., contacting it at four locations spaced 90° from each other around the circumference of the hollow cylinder) or it can have a square profile such that the hollow cylinder only contacts the eyelet at two location spaced 180° from each other around the circumference of the hollow cylinder. 
     In any of the embodiments discussed hereinabove in connection with the use of a hollow cylinder in the eyelet, it may be preferable to round out the proximal end of central pin  402  so as to avoid any sharp edges. This would help avoid the possibility of the central pain punching a hole through the hollow cylinder without substantially deforming it. 
     Seventh Set of Exemplary Embodiments 
       FIGS. 50 and 51  are cross-sectional views illustrating another alternative embodiment  400 ″ to the bone anchor device  400  shown in  FIGS. 36-41 .  FIG. 50  shows the bone anchor device  400 ″ in the open position, while  FIG. 51  shows it in the closed position. The device  400 ″ is largely similar to device  400  shown in  FIGS. 36-41 . However, the eyelet pin  403 ″, insert  405 ′, and central pin  402 ′ are modified, providing a different mechanism for fixing a suture  46  in the bone anchor device  400 ″. Particularly, the significant modifications are as follows. First, central pin  402 ′ includes its own eyelet  481  near its proximal end, which aligns with eyelet  409  in the eyelet pin  403 ″ when in the open position, as shown in  FIG. 50 . Second, the proximal bore  415 ″ in the eyelet pin  403 ″ is slightly larger in diameter than the distal bore  417  and the central pin  402 ′. However, it should be noted that this is not necessarily a modification since the diameter of the proximal bore  415  relative to the distal bore  417  in the embodiment of  FIGS. 36-41  was not specified. Also, the proximal bore  415 ″ extends to and is in communication with eyelet  409  in the eyelet pin  403  (similarly to the embodiment of  FIG. 44F ). Insert  405  also is modified such that the shoulder  435 ′ between the larger internal diameter of the proximal segment  433 ′ and the smaller internal diameter of the distal segment  431 ′ is lower. Although, again, this is not necessarily a modification since the position of shoulder  435  between the larger internal diameter of the proximal segment  433  and the smaller internal diameter of the distal segment  431  of the insert  405  in the embodiment of  FIGS. 36-41  was not specified. 
     In this embodiment, the suture becomes locked in the device  400 ″ by means of the two eyelets  409  and  481  shifting in longitudinal position relative to each other. Particularly, in the open position, the eyelet  481  in the central pin in longitudinally aligned (and also rotationally aligned about the longitudinal axis) with the eyelet  409  in the eyelet pin so that one or more sutures may pass through the eyelets  409 ,  481  essentially as described in connection with the embodiment of  FIGS. 36-41 . Then, when the eyelet pin is driven downwardly, the central pin moves downwardly until it bottoms out in the bottom of distal segment  418   c  of bore  418  in anchor main body  401 , whereupon the force imparted to eyelet pin  403 ″ overcomes the force of the interference fit between the central pin  402 ′ and the distal bore  417  of eyelet pin  403 ″ as well as forces ramp formation  407  past locking ring  404  and into the closed position. This causes the eyelet  409  in the eyelet pin  403 ″ to move downwardly relative to the eyelet  481  in the central pin  402 ′. It can be seen in  FIG. 51  that, in the closed position, the resulting longitudinal misalignment of the two eyelets  481  and  409  causes any suture(s) passing through the eyelets to take on a tortuous path and to become compressed and locked to the bone anchor device  400 ″ at four separate locations. The first two are two of the same locations as in the embodiment of  FIGS. 36-41 , namely, at opposite ends  409   a  and  409   b  of the eyelet  409  between the outer surface  416  of the eyelet pin and the proximal section  433 ′ of the insert  405 ′. The other two are between the surface of the central pin  402 ′ and the proximal bore  415 ″ of the eyelet pin  402 ″, as indicated at  463  in  FIG. 51 . 
     It now should be apparent that the reason the proximal bore  415 ″ is preferably slightly larger than the distal bore  417  proximal bore and the central pin  402 ′ is to provide clearance for the sutures between the two. It also should now be apparent that the reason the shoulder  435 ′ in the insert preferably is lower than in the embodiment of  FIGS. 36-41  also is to provide sufficient clearance for the suture(s) between the insert inner bore and the surface  416  of the eyelet pin  416 . More particularly, in this embodiment, because there must be room in the portion of the eyelet pin  403 ″ above the eyelet  409  to accommodate both the eyelet  481  of the central pin  402 ′ and a portion of the pin  402 ′ above the eyelet  481  while still preferably maintaining the breakaway V-groove  413  essentially flush with the top of the anchor main body  401  in the closed position, the eyelet  409  in the eyelet pin  403 ″ preferably is positioned lower into the anchor main body  401  when in the closed position than in the embodiment of  FIGS. 36-41 . Of course, these particular modifications are merely exemplary insofar as different sets of modifications may be implemented to achieve similar goals. 
     This embodiment provides secure fixing of the suture(s) in the bone anchor device 
     In these types of embodiments, the bone anchor device could even possibly be delivered to the surgeon already in the closed state with or without one or more sutures already disposed in and passing through the eyelet. 
     Eighth Set of Exemplary Embodiments 
       FIGS. 52A-56C  illustrate another set of embodiments of a bone anchor in accordance with the present invention as well as a tool for implanting the bone anchor. Some of the benefits of these embodiments include that the bone anchor may be implanted using a single tool, the bone anchor and tool can be delivered to the surgeon as a single inseparable unit until implantation so that no parts can be lost and there is no possibility of incorrect assembly. It also facilitates ease of use. 
     The bone anchor in this embodiment is similar in many respects to the bone anchor embodiments disclosed in  FIGS. 36-41 . Accordingly, the following discussion will focus primarily on the differences of this embodiment relative to the embodiments of  FIGS. 36-41 . 
     An example of an eyelet pin in accordance with this set of embodiments is shown in perspective view in  FIG. 52A  and in plan view in  FIG. 52B . A cross-sectional side view of an example of an anchor main body in accordance with this set of embodiments is shown in  FIG. 53 . In this embodiment, the eyelet pin  521  is modified in several respects. First, the cylindrical radial surface of the eyelet pin  410  of  FIGS. 36-41  is modified in the present embodiment to have two flattened portions  525   a ,  525   b  near its proximal end adjacent the opposite ends of the eyelet  523 , as best seen in  FIG. 52B . This feature provides several significant benefits. First, it allows the clearance between the outer radial wall  527  of the eyelet pin  521  and the inner radial wall  550  of the anchor main body  580  (see  FIG. 53 ) to be much smaller in all places except at the flattened portions  525   a ,  525   b . More particularly, as previously noted, a clearance must be provided between the eyelet pin outer radial wall and the main anchor body inner radial wall for the sutures that will pass through the eyelet  523  and out of the anchor main body  580 . However, this clearance is necessary only at the opposite ends of the eyelet  523  and nowhere else. Thus, by flattening the radial side wall  527  of the eyelet pin  521  adjacent the opposite ends of the eyelet  523 , the eyelet pin diameter (in the portions of the eyelet pin that are still cylindrical) can be made larger so as to minimize the clearance between the eyelet pin  521  and the anchor main body  580  at the proximal end  521   a  of the eyelet pin  521 . This allows the eyelet pin to be made sturdier because it is thicker (except in the portions where it is flattened). 
     The flattened portions  525   a ,  525   b  also provide a benefit with respect to the fabrication of the eyelet pin  521 . Particularly, the flattened portions  525   a ,  525   b  make it easier to form bevels  529  at the opposite ends of the eyelet  523  and to eliminate sharp edges where the sutures will enter the eyelet. Sharp edges at the opposite ends of the eyelet could obstruct effortless passage of sutures through the eyelet. The beveled edges provide a funnel-like entry to the eyelet, thus gathering the suture bundle prior to entering the eyelet. If the outer radial surface of the eyelet pin were curved at the opposite ends of the eyelet, it would be more difficult to machine or otherwise form the bevels  529  without also forming sharp edges in the bevels themselves. 
     Also in this embodiment and with reference to  FIGS. 56A-56C , which are an exploded view and two orthogonal side cross-sectional assembled view, respectively, of the bone anchor and associated implantation tool, the central pin  531  has a shelf  533  formed therein. The distal surface  533   b  of the shelf serves as a stop for the central pin  531  from having its distal end bottom out on the distal extent  559  of the longitudinal bore  560  of the main anchor body  580 , while the proximal surface  533   a  defines a stop for the eyelet pin  521  relative to the central pin  531 . Particularly, as will be discussed in more detail below, the distal end  521   b  of the eyelet pin  521  will hit and be stopped by the upper surface  533   a  of the shelf  533  as the eyelet pin  521  is being driven down over the central pin  531  from the open condition to the closed condition. 
     In this embodiment, the breakaway portion  410  of the eyelet pin  401  of  FIGS. 36-41  is eliminated. Since, as will be discussed in more detail below, the anchor and tool are attached to each other until near the end of the implantation procedure, there is no need for an eyelet pin extension to help with finding the bone anchor after it is implanted. 
     With reference to  FIG. 53 , the anchor main body  580  in this embodiment also differs slightly from the anchor main body  401  in the embodiments of  FIGS. 36-41 . As in the embodiments of  FIGS. 36-41 , the anchor main body  580  has an internal bore  560  having three different sections  560   a ,  560   b ,  560   c  of decreasing diameter from proximal end  580   a  to distal end  580   b . As best seen in  FIG. 56A , the bore  560  accepts the central pin  531 , eyelet pin  521 , C-ring  551 , and retaining ring  541  as in the embodiments of  FIGS. 36-41 . However, in the embodiments of  FIGS. 36-41 , the proximal end of the anchor main body  401  has an external formation  423  for mating with a torquing tool having mating internal formations for screwing it into bone. In this embodiment, on the other hand, the proximal end  560   a  of the longitudinal internal bore  560  of the anchor main body  580  bears a formation  584  for mating with external formations on a torquing tool (not shown) to permit the torquing tool to rotate the bone anchor for purposes of screwing the bone anchor into bone. 
     Finally, with reference to  FIGS. 56A-56C , the retaining ring  541  that holds the C-ring  551  (or other locking ring or mechanism for maintaining the eyelet pin in the anchor) differs from the insert  405  shown in the embodiments of  FIGS. 36-41 . In accordance with the present embodiment, the retaining ring  541  per se may be virtually physically identical to the insert  405  discussed above in connection with the embodiments of  FIGS. 36-41 , except that the retaining ring  541  is integral with the implantation tool in the pre-surgical condition. The retaining ring  541  becomes separated from the implantation tool only towards the end of the implantation process, as will be described in more detail below. 
     More particularly, referring now to  FIGS. 54A ,  54 B,  55 A,  55 B,  56 A,  56 B, and  56 C, the implantation tool  561  is shown in perspective view in  FIG. 54A  and in cross sectional side view in  FIG. 54B .  FIGS. 55A and 55B  are a close up cross-sectional side view and an exploded view, respectively, of the proximal portion of the tool,  FIGS. 56A ,  56 B, and  56 C are an exploded perspective view and two orthogonal cross-sectional side views, respectively, of the distal portion of the tool with a bone anchor mounted thereon. The tool  561  can be considered to comprise four main parts. They are a shaft  563  with a through bore, a handle  564  attached to the proximal end of the shaft  563 , a rod  565  extending through the bore of the shaft  563 , and a nut  566  positioned inside a longitudinal bore  567  in the handle  564  and threaded onto the proximal end  563   a  of the shaft  563 . The handle  564  is fixedly attached to the shaft  563 . In the illustrated embodiment, for instance, two pins  575   a ,  575   b  pass through lateral holes  578   a ,  578   b  in the handle and occupy mating depressions  577   a ,  577   b  in the shaft  563  so that the shaft  563  cannot rotate or move longitudinally relative to the handle  564 . The two pins  575   a ,  575   b  form an interference fit with their respective holes  578   a ,  578   b  and, therefore, are essentially fixed to the handle  564 . 
     The handle may include two cleats  576   a ,  576   b  that can be used for temporarily securing the tensioned ends of sutures after passing through the eyelet of the eyelet pin, thus freeing one of the hands of the surgeon during implantation, as will be described in further detail below. 
     Referring to the cross-sectional and exploded views of  FIGS. 55A and 55B  of the proximal end  561   a  of the implantation tool  561 , the proximal end  563   a  of the shaft  563  bears external threads  568  designed to accept mating internal threads  569  in a longitudinal distal blind bore  570  in the nut  566 . The proximal bore  571  is configured in cross-section to accept the head of a torquing tool, e.g., a screwdriver or nut driver (not shown) that will be used to rotate the nut  566  relative to the shaft  563  within the handle. The cross-section of the proximal longitudinal bore of the nut may, for instance, be hexagonal so as to accept the head of a hexagonal driver. The rod  565  inside the shaft  563  extends past the proximal end  563   a  of the hollow shaft and into the distal bore  570  of the nut  566 . An optional bushing  573  may be placed on the proximal end of the rod that provides an interface between the nut and the rod so that the rod  565  will not rotate when the nut  566  is rotated. 
     With this configuration, when the nut  566  is rotated, the mating threads  568 ,  569  of the distal bore  570  of the nut  566  and the proximal end  563   a  of the shaft  563  will cause the nut  566  to travel longitudinally relative to the shaft  563 . Assuming the use of standard right handed threads, clockwise rotation of the nut  566  (as viewed from above the nut) will cause the nut to walk down the shaft  563 , thus pushing the rod  565  distally out of the distal end  563   b  of the hollow shaft  565 . Counterclockwise rotation of the nut will cause the nut  566  to walk proximally up the shaft  563 . However, counterclockwise rotation of the nut  566  will not necessarily draw the rod  565  proximally because the rod is not mechanically attached to the nut, it only abuts it. 
     Referring to the cross-sectional side and exploded views of  FIGS. 56A ,  56 B, and  56 C of the distal portion of the implantation tool  561 , the tool  561  preferably is delivered to the surgeon with the anchor  581  fixedly mounted on it. As will become clear from the following discussion, the distal end  563   b  of the shaft  563  is fixedly coupled to the anchor main body  580  of the anchor  581  via the retaining ring  541 . Specifically, the retaining ring  541  is fixed both to the anchor main body  580  (by virtue of being in an interference fit within the longitudinal bore  560  of the anchor main body  580 ) and also to the tool  561  (by virtue of the retaining ring  541  being integrally formed as a frangible part of the distal end  563   b  of the shaft  563  of the tool  561  in the pre-surgical condition). 
     The entire shaft  563  of the tool may be a single, monolithic piece. However, in this particular embodiment, as can be seen in  FIGS. 56A ,  56 B, and  56 C, the distal-most portion of the shaft  563  comprises a separate, titanium end piece  591  that may be fixed to the main portion of the shaft  563  by any reasonable means. The distal portion  563   b  of the shaft  563  is a separate piece  591  in this particular embodiment because a portion of it (namely, the retaining ring  541 ) is an implantable piece and, therefore, needs to meet the requirements for human implantation. The rest of the shaft, however, is not implantable, and therefore can be made of a different material. Of course, in other embodiments, the entire shaft  563  can be made of implantable-grade material and thus be monolithic. 
     Also, in the pre-surgical condition, the distal end  565   b  of the rod  565  abuts the proximal end  521   a  of the eyelet pin  521  in the anchor  580 . Although not included in the illustrated embodiment, a nub may be provided at the distal end  565   b  of the rod for engaging the bore  574  in the proximal end  521   a  of the eyelet pin  521  for alignment purposes. Thus, when the rod  565  is pushed distally relative to the shaft  563  by clockwise rotation of the nut  566 , the rod  565  pushes the eyelet pin  521  distally relative to the shaft  563 , the anchor main body  581 , and the central pin  531 , all of which are essentially longitudinally fixed relative to each other by means of the retaining ring  541 . On the other hand, if the rod  565  moves proximally relative to the shaft  563 , the central pin  531  is unaffected (because the abutting nature of the interface between the distal end  565   b  of the rod  565  and the proximal end  521   a  of the eyelet pin  521  allows only for pushing of the eyelet pin  521  in the distal direction, and not pulling in the proximal direction by the rod  565 ). 
     The outer radial surface  563   c  at the distal end  563   b  of the shaft  563  is formed with a pattern to mate with a pattern  584  in the largest and most proximal portion  560   c  of the internal bore  560  of the anchor main body so that the twisting of the handle  564  and shaft  563  also twists the anchor main body  580  when the tool  561  is mounted to the anchor  581 . Thus, the bone anchor  581  may be screwed into bone by twisting the tool  501  (at the handle  564 ). 
     The retaining ring  541  is frangibly attached to the distal end  563   b  of the shaft  563  by one or more breakaway portions. In this particular embodiment, the breakaway portions comprise two breakaway portions  590   a ,  590   b  positioned 180° radially from each other around the circumference of the shaft  563 . The thickness, shape, and length of the breakaway portions  590   a ,  590   b  are designed to cause the retaining ring  541  to break off from the shaft  563  when a longitudinal force greater than a predetermined force, that is less than the interference force between the retaining ring  541  and the anchor body  580 , is applied to the shaft  563 , as will be described in greater detail below. Optionally, another, friction ring  552  may be positioned over the eyelet pin  521  over the frangible portions  590   a ,  590   b  just proximal of the retaining ring  541  to absorb any force loading that might otherwise load the frangible portions  590   a ,  590   b  prematurely. For instance, during assembly, lateral loading may occur that might break the frangible portions  590   a ,  590   b . With the friction ring  552  in place, the friction ring  552  will take those loads rather than the frangible portions. If used, the inner radial surface of friction ring  552  is frictionally engaged with the outer radial surface of the eyelet pin  521  to hold it in place. As best seen in  FIG. 56C , the proximal end of the retaining ring  541  may include an inner radial groove  553  for accepting the distal end of the friction ring  552  in the groove and trapped between the outer radial surface of the eyelet pin  521  and the side wall of the groove  553 . The friction ring  552  may be made of a compressible material and have a wall thickness (at least at its distal end) slightly larger than the width of the groove between the side wall of the groove and the outer radial surface of the eyelet pin so as to form a compression fit in the groove  553 . 
     The eyelet pin may be formed to have an overhang (or widened portion)  524  at its proximal end to help retain the retaining ring  541  and/or friction ring  552  within the anchor body. Further, as will be discussed further below, the bone anchors of the present invention are redeployable and intra-operatively adjustable and the widened portion  524  can also serve as a guide for an adjustment and/or redeployment tool that must be inserted into the implanted anchor to adjust or remove it. 
     The distal portion  563   b  of the shaft  563  has a discontinuous radial surface. Particularly, it includes slots  593   a ,  593   b  disposed 180° radially from each other around the circumference of the shaft  563 . The slots  593   a ,  593   b  should be aligned radially with the eyelet openings in the eyelet pin  521  when the anchor  581  is mounted on the tool  561 . Accordingly, any sutures and a suture shuttle may pass through the eyelet  523  in the eyelet pin  521  without interference from the tool  561  during any of the implantation and tissue attachment processes as described hereinabove or hereinbelow. Furthermore, the outer surface of the shaft  563  includes two flats  594   a ,  594   b  (they could also be grooves) running longitudinally along the length of the shaft and positioned 180° radially from each other around the perimeter of the shaft and aligned with the aforementioned slots  593   a ,  593   b . Each of these grooves  594   a ,  594   b  provides a defined channel within which a suture or suture shuttle may run up to the handle  564  and be tensioned onto the cleats  576   a ,  576   b  of the handle. Accordingly, the cleats  576   a ,  576   b , the longitudinal grooves  594   a ,  594   b , the slots  593   a ,  593   b , and the opposing ends of the eyelet  523  of the eyelet pin  521  are all radially aligned with each other. 
       FIGS. 56A ,  56 B, and  56 C also show an exemplary optional suture shuttle  601  not shown in  FIGS. 54A-55B . The suture shuttle is in the form of a ribbon (to be described in greater detail hereinbelow) passing through the slots  593   a ,  593   b , and eyelet in the eyelet pin  521 , and up along the grooves  594   a ,  594   b  on the shaft  563 . As best seen in  FIGS. 56A and 56C , the proximal edges  593   a - 1 ,  593   b - 1  of the slots  593   a ,  593   b  are beveled or angled to allow the suture shuttle  601  to bend gradually and less tortuously as it passes through the tool and eyelet. In accordance with another option shown in  FIGS. 56A and 56C , a pair of rails  595   a - l ,  595   a - r  may be provided on opposing sides of flat portion  594   a  and another pair of rails  594   b - l ,  594   b - r  may be provided on opposite sides of flat portion  594   b  at tool  561  to further protect the suture shuttle  601  and any sutures from binding as they are shuttled through the tool and eyelet. Particularly, if the bone anchor is implanted below the surface of the bone, the slots  593   a ,  593   b  may be beneath or very close to the bone such that the suture shuttle  601  or sutures could be squeezed between the bone and the side of the tool and, therefore, difficult to pull through the tool and eyelet. The rails on each side of the suture shuttle  601  will assure a sufficient channel for the suture shuttle and sutures to slide freely. 
     An exemplary use of the anchor and implantation tool in accordance with this embodiment will now be described. As previously noted, the apparatus is preferably delivered to the surgeon in the pre-surgical condition with the anchor  581  affixed to the implantation tool  561 . Particularly, as previously noted, the retaining ring  541  is frangibly attached to the distal end of the hollow shaft  563  of the implantation tool  561  (e.g., via the breakaway portions  590   a ,  590   b ) and also is affixed to the anchor main body  580  by virtue of being in an interference fit within the anchor main body&#39;s longitudinal bore portion  560   a.    
     Once the surgical site is prepared and the bone exposed, the surgeon screws the anchor  581  into the bone with the tool by grasping the handle  564  of the implantation tool  561  and twisting it to screw the bone anchor main body  580  into the bone. The screwing of the anchor  580  into the bone does not load the breakaway portions  590   a ,  590   b  because the entire load is borne by the mating internal formation  584  on the anchor main body  580  and external formation  563   c  on the outer surface of the distal end  503   b  of the shaft  563 . Next, with the tool  561  still attached to the now implanted anchor  581 , sutures are attached to tissue and passed through the eyelet  523  of eyelet pin  521  of the anchor such as described in connection with the various surgical procedures discussed above in this specification. 
     When the surgeon has pulled the sutures through the eyelet  523  and tensioned them to the desired tension with the tissue in the desired position, the surgeon can temporarily secure the tensioned sutures to the cleats  576   a ,  576   b  in the handle  564  ( FIG. 54A ), thus freeing a hand. Now, the eyelet pin  521  is ready to be driven distally into the anchor main body  580  and over the central pin  531  into the closed position, thereby locking the sutures in the eyelet  523 . This is accomplished as follows. First, the surgeon slips a torquing tool into the proximal bore  571  of the nut  566 . While holding the handle  564  of the implantation tool  561  steady, the surgeon turns the torquing tool clockwise to cause the nut  566  to walk down the threads  568  at the proximal end  563   a  of the shaft  563 . This forces the rod  565  to move distally relative to the shaft  563  since its proximal end  565   a  is abutting the distal end of the distal bore  570  of the nut  566 . Since the distal end  565   b  of the rod is abutting the proximal end  521   a  of the eyelet pin  521  and the shaft  563  is fixed to the anchor  581 , as long as the breakaway portions  590   a ,  590   b  are still intact, this drives the eyelet pin  521  down over the central pin  531  into the anchor main body  580  and into the closed position. As previously described in connection with the embodiments of  FIGS. 36-41 , the eyelet pin  521  is substantially fixed to the central pin  531  by virtue of an interference fit between the distal bore  522  of the eyelet pin  521  and the outer peripheral surface of the central pin  531 . This fixation is overcome by the significant longitudinal force applied to the eyelet pin  521  via the torquing tool through the substantial leverage provided by the mating threads  568 ,  569 , which convert a relatively small torque force into a substantial longitudinal force. As the eyelet pin  521  is pushed down over the central pin  531 , the second ramp formation  524  of the eyelet pin  521  eventually passes through the C-ring  551 , which causes the C-ring to expand to allow the ramp formation  524  to pass through and then snap shut once the second ramp formation  524  completely clears the C-ring  551 . At this point, the eyelet pin  521  is now trapped in the closed position with the one or more sutures trapped in the eyelet  523  because the suture(s) are captured between the central pin  531  and an internal surface of the eyelet  523  as previously described in connection with the embodiments of  FIGS. 36-41 . 
     In any event, the eyelet pin  521  will eventually bottom out in the anchor, i.e., the distal end of the eyelet pin  521  will eventually hit the upper surface  533   a  of the shelf  533  of the central pin  531  and, therefore, be unable to move distally any farther relative to the central pin  531 . At that point, continued clockwise turning of the nut  566  will attempt to move the nut  566 , rod  565 , and eyelet pin  521  relative to the shaft  563 . However, since the eyelet pin  521  can no longer travel distally relative to the central pin  531  and anchor main body  580  once it has bottomed out on top surface  533   a  of the shelf  533 , the continued clockwise twisting of the nut  566  will instead attempt to cause the shaft  563  to start moving proximally relative to rod  565  and eyelet pin  521 . As the system now has no mobility, any clockwise rotation of nut  566  will load the system longitudinally due to the significant mechanical advantage of the screw threads acting upon the rod  565 . The weakest structural portions in the assembly are the breakaway portions  590   a  and  590   b , which are being loaded in longitudinal tension. This will cause the breakaway portions  590   a ,  590   b  to fail, thereby detaching the retaining ring  541  from the shaft  563 . 
     The breakaway portions  590   a ,  590   b  are designed to break in response to a longitudinal force that is less that the longitudinal force needed to pull the retaining ring  541  out of its interference fit within the longitudinal bore  560  of the anchor main body  580 . In one embodiment, the breakaway portions  576   a ,  576   b  are designed to fail at a force of about 150 pounds through manual, relatively low torsional force being applied to the nut  566 . 
     At this point, the tool  561  is now detached from the anchor  580  and can be removed. The surgery can now be completed in the usual fashion. 
     The sutures may now be released from the cleats and the excess suture may be cut. 
     In accordance with the above description, it should be clear that yet another advantage of this particular embodiment is that the eyelet pin  521  is driven down over the central pin  531  slowly and atraumatically, rather than being hit with a mallet or other traumatic striking tool as was described earlier. 
       FIGS. 73A through 76  illustrate an alternative embodiment of a tool/anchor combination for use with the particular anchor device of the embodiment of  FIGS. 71A through 72B  (the embodiment with the flared central pin). This embodiment provides a different mechanism for retaining the anchor device to the tool and for releasing the anchor device from the tool after implantation and the eyelet pin is deployed into the closed position. 
     First, with reference to  FIGS. 73A-73C , the distal-most end piece of the shaft  591  of the tool embodiment just discussed is replaced with an alternate end piece  591 ′.  FIG. 73A  is a perspective view of the end piece  591 ′. It comprises two primary portions, namely, a main body portion  2511 , illustrated separately in  FIG. 73B , and an anchor retention element  2501  illustrated separately in exploded view relative to the main body portion  2511  in  FIG. 73C . 
     Particularly, end piece  591 ′ is similar to piece  591 , with the most significant differences being the elimination of the retaining ring  541  and frangible elements  590   a  and  590   b . Rather, an anchor retention element  2501  (see  FIGS. 73C ) is employed to retain the tool to the anchor until the anchor is implanted and the eyelet pin is deployed into the closed position. With reference to  FIG. 73C , the anchor retention element  2501  is a hollow cylinder with longitudinal slits  2502  in its distal portion. Accordingly, the distal portion of anchor retention element  2501  comprises a plurality of longitudinally extending fingers  2503  (in this example, 4). Disposed on the outer surface of the distal end of each finger  2503  is a latch  2504 , as perhaps best seen in  FIGS. 76A-76D , which are discussed in detail below. To assemble the end piece  591 ′, the fingers  2503  of the anchor retention element  2501  are slid into the internal bore  2512  of the main body  2511  from the proximal direction with the fingers  2503  sliding into and through openings  2513  into recesses  2514  of end piece main body  2511  until the latches are in the position shown in  FIG. 73A . The anchor retention element  2501  can slide freely longitudinally within the main body within a limited longitudinal range. Particularly, the shoulders  2506  at the proximal ends of the fingers will limit movement of the anchor retention element in the distal direction at the point where those shoulders  2506  meet the edges of the openings  2513  in the main body  2511  and the latches  2504  will limit movement of the anchor retention element in the proximal direction at the point where those latches  2504  meet the edges of the openings  2513 . The length of the fingers is selected so that the latches can extend distally beyond the position illustrated in  FIG. 73A  for reasons that will become clear below. 
       FIG. 74  is a perspective view of an anchor main body  580 ′ in accordance with this embodiment. It may be substantially similar to any of bone anchors  580 ,  581 , or  401  previously discussed herein, except for the addition of lateral through holes  2520  at its proximal end for receiving latches  2514 , as will be described in more detail below. 
     The anchor may now be attached to the tool by sliding the end piece  591 ′ onto the tool as shown in  FIG. 75 .  FIG. 75  shows the assembly of the end piece  591 ′ of the shaft&#39;, comprising pieces  2501  and  2511  assembled to the anchor body  580 ′, but disembodied from the rest of the tool for clarity. The fingers  2503  of the anchor retention element  2501  are flexible. They are essentially leaf springs suspended at their proximal ends. Accordingly, the tool can be assembled to the anchor main body as shown in  FIG. 75  by sliding the anchor retention element to its distal-most position within the main body  2511  so that the latches extend beyond the distal end of the main body  2511 . This will allow the fingers to flex inwardly when the end piece  591 ′ of the tool is inserted into the anchor main body to clear the substance of the anchor main body until the latches  2504  meet the holes  2520 , at which point the fingers  2503  will resiliently snap back outwardly, thereby locking the tool to the anchor main body  580 ′ via the engagement of the latches  2514  on the anchor retention element  2501  within the holes  2520  of the anchor main body  580 ′. If the anchor retention element is not slid all the way distally so that the latches extent beyond the distal end of the recesses  2514  of the main body  2511 , then the recesses will block the fingers  2503  from flexing inwardly. After the latches have engaged the holes, the main body  2511  can be slid distally relative to the anchor retention element  2501  back to the position shown in  FIGS. 73A and 75 . With element  2511  in this position, the fingers  2503  will be unable to flex inwardly. This will prevent the latches  2504  from inadvertently disengaging from the holes  2520  until the main body  2511  is again moved proximally relative to the anchor retention element  2501 . 
       FIGS. 76A-76D  illustrate operation of the tool/anchor assembly of this embodiment, showing the assembly at different, progressive stages of use.  FIG. 74A  shows the tool/anchor assembly in cross-section with the eyelet pin in the open, undeployed position prior to implantation, i.e., the same position illustrated in  FIG. 75 . Note that, in this position, the proximal portion of the eyelet pin  403 ′ provides even further support to the recesses  2414  of the end piece main body  2511  for preventing the fingers  2504  of the anchor retention element  2501  from inadvertently flexing inwardly and releasing from the holes  2520  in the anchor main body  580 ′. 
     At this point, the tool and anchor are ready for implantation. Specifically, rotation of the tool will be imparted to the anchor for purposes of screwing the anchor into bone due to the fact that the engagement of the latches  2514  in the holes  2520  rigidly attaches the tool to the anchor main body  580 ′. 
     Then, after the anchor is implanted, the eyelet pin  403 ′ can be deployed into the closed position as illustrated in  FIG. 76B  and as substantially described in connection with the previous embodiment, i.e., by driving a rod down the central bore  2531  of the tool that pushes the eyelet pin down over the central pin while the outer shaft of the tool (comprising end piece  591 ′) remains stationary, thereby holding the anchor main body  580 ′ (and central pin  402 ′) from moving while the eyelet pin  403 ′ is being driven down into the closed position. 
     At this point, with reference to  FIG. 76C , the shaft of the tool, including the end piece main body  2511 , is pulled proximally. Only the end piece main body  2511  moves proximally with the rest of the shaft, while the anchor retention element  2501  remains in its original position since the latches still are engaged within the holes  2520 . Thus, the end piece main body  25111  can be withdrawn proximally relative to the anchor retention element  2501  only until the shoulders  2505  at the proximal ends of the fingers  2503  hit the proximal ends of the channels  2514  adjacent the opening  2513  of the main body  2511 . At that point, the end piece main body  2511  cannot be withdrawn proximally any further until the latches  2504  are released from the holes  2520 . 
     Thus, as seen in  FIG. 76C , with the end piece main body withdrawn in the proximal direction, the fingers  2503  are now free once again to flex inwardly in order to permit the tool to be released from the anchor. Thus, referring to  FIG. 76D , the fingers may be flexed inwardly to release the latches  2514  from the holes  2520  so that the tool can be completely withdrawn. 
     Obviously, the diameter of the proximal portion of the eyelet pin  403 ′ relative to the diameter of the proximal portion  418   a ′ of the longitudinal bore  418 ′ in anchor main body  580 ′ is selected so as to provide enough clearance for the latches  2504  to escape from the holes  2520  without being blocked by the eyelet pin. As this point, the tool can be withdrawn completely. 
       FIGS. 77A through 77C  show some features that may be incorporated into the proximal portion of the implantation tool to accompany and work with the distal features discussed above in connection with  FIGS. 73A to 76D .  FIG. 77A  shows a modified nut  566 ′. The nut  566 ′ also is seen in cross section in  FIGS. 78A ,  79 A,  80 A, and  81 A. Nut  566 ′ is substantially similar to nut  566  of  FIGS. 55A and 55B , except for the addition of a breakable cross pin  771  that passes transversely through distal bore  570 ′ of nut  566 ′ and against which abuts the proximal end of the rod  565 ′ that drives the eyelet pin down into the closed position (as best seen in  FIG. 78A ). The breakable pin  711  is designed to break when the pressure exerted by the rod on it reaches a certain force. The purpose of the breakable cross pin  771 , as will be described in more detail below, is to break after the eyelet pin is bottomed out in the bore of the anchor main body in the closed position. This serves two goals. First, it providing a tactile (and/or audible) snap signifying to the surgeon that the eyelet pin has reached the closed position. Second, as will become clear from the discussion below, after the pin breaks, no further downward force can be exerted on the eyelet pin. Hence, the deployment of the eyelet pin into the closed position is ceased at and dictated by a predetermined force, rather than a predetermined distance. This provides a more repeatable and accurate design since the force is dictated by a single structural element, i.e., the breakable cross pin  771 , as opposed to eyelet pin deployment being dictated by a distance, which could be quite variable when the tolerances of all of the elements that must move relative to each other to deploy the eyelet pin into the closed position are stacked upon each other. 
     In addition to the nut  566 ′ and breakable cross pin  771 ,  FIG. 77A  also shows a slightly modified rod  565 ′ and a slightly modified shaft  563 ′ for this embodiment as well as two new elements, namely, gate  772  and cam member  773 . These elements are shown disembodied from the rest of the handle hardware for purposes of clarity. However, cam member  773  is within a longitudinal bore within the handle, the bore being sufficiently long that the cam member has room to longitudinally translate within the handle, as seen in  FIG. 78A  and as will be described in detail below. Gate  772 , on the other hand, is longitudinally fixed within the handle by virtue of being within a transverse slot (see  781  in  FIG. 78A , for instance) in the handle. The gate  772  is U-shaped with two arms  778 ,  779  extending substantially parallel to each other from a common based  781 . Although the gate  772  is trapped longitudinally within the slot  781  in the handle, the slot does provide room for the arms  778 ,  779  of the gate  772  to spread apart from each other as will be described in detail below. 
       FIG. 77B  shows essentially the same view as in  FIG. 77A , except with the shaft  563 ′ omitted so that the proximal ends of the rod  565 ′ and anchor retention element  2501  that are inside the shaft can be seen. Rod  565 ′ and shaft  563 ′ may be essentially identical to rod  565  and shaft  563  of the embodiments of  FIGS. 54A to 55B  (see also  FIGS. 71A-76D ), except that the shaft has a skive  777  to receive the arms  778 ,  779  of the gate  772 .  FIG. 77C  is a close up view of the shaft  563 ′ showing the skive  777  in detail. The proximal end of anchor retention element  2501  (see  FIG. 73C  for distal end of anchor retention element  2501 ) includes a similar skive for receiving the arms of the gate  772 . 
     The cam member  773  comprises an annulus  775  at its proximal end that surrounds the shaft  563 ″ and a wedge  774  at its distal end that extends between the two arms  778 ,  779  of the gate  772 . 
     As best seen in  FIG. 77A , the arms of the gate  772  sit within the skive  777  of the shaft  563 ′. As best seen in  FIG. 77B , the arms of the gate  772  also sit within a similar skive  782  in the anchor retention element  2501  and prevent the anchor retention element  2501  from moving relative to the handle (because the gate  772  is actually longitudinally immovable within a slot  781  in the handle  564 ′, as seen, for instance, in  FIG. 78A ) until the arms  778 ,  779  of the gate  772  are spread apart and out of the skive  780  by the wedge  774  of cam member  773 , as will be discussed in more detail below. Briefly, however, as the nut  556 ′ is turned to force it distally relative to the shaft  563 ′ to which it is threadedly engaged (as previously described in connection with nut  566  of  FIGS. 54A to 56B ), the nut  556 ′ eventually contacts the annulus  775  at the proximal end of cam member  773  and starts to push cam member  773  distally. This causes the wedge  774  at the distal end of the cam member  773  to slide between the arms  778 ,  779  of the gate  772  and force the gate&#39;s arms  778 ,  779  away from each other and out of engagement within the skive  780 , at which point the anchor retention element  2501  can translate longitudinally relative to the handle  564 ′ and the shaft  563 ′. Note that the removal of the gate  772  from engagement with skive  777  in the shaft  563 ′ will have no effect on the shaft because the shaft  563 ′ is permanently fixed to the handle by other means. 
       FIGS. 78A ,  78 B,  79 A,  79 B,  80 A,  80 B,  81 A, and  81 B illustrate operation in accordance with this aspect of the invention. More specifically,  FIGS. 78A ,  79 A,  80 A, and  81 A are cross sectional views of the proximal end of the implantation tool in accordance with the embodiment of  FIGS. 77A-77C  and the anchor of  FIGS. 71C-71F  at four different stages of deployment of the eyelet pin.  FIGS. 78B ,  79 B,  80 B, and  81 B show the positions of the various components at the distal end of the tool for the same stages. Specifically, (1)  FIG. 78A  shows the condition of the various components at the proximal portion of the tool when the eyelet pin is in the open position before any deployment toward the closed position, while  FIG. 78B  shows the condition of the various components at the distal portion of the tool at the same stage; (2)  FIG. 79A  shows the condition of the various components at the proximal portion of the tool when the eyelet pin first bottoms out in the bore of the anchor main body, while  FIG. 79B  shows the corresponding condition of the various components at the distal portion of the tool at the same stage; (3)  FIG. 80A  shows the condition of the various components at the proximal portion of the tool after the breakable pin has broken, while  FIG. 80B  shows the condition of the various components at the distal portion of the tool at the same stage; and (4)  FIG. 81A  shows the condition of the various components at the proximal portion of the tool after the gate has released the shaft for movement, while  FIG. 81B  shows the corresponding condition of the various components at the distal portion of the tool at the same stage. Note that the operation at the distal end of the tool as shown in  FIGS. 78B ,  79 B,  80 B, and  81 B is essentially the same as already described above in connection with  FIGS. 76A-76D , the main difference being that it is being used with the anchor of  FIGS. 71C-71F , rather than the anchor of  FIGS. 72A , but is shown here as a frame of reference for the operation at the proximal portion of the tool. Also note that only the annulus  775  of the cam member  773  can be seen in  FIGS. 78A ,  79 A,  80 A, and  81 A because the wedge  774  is behind the shaft  563 ′ and rod  565 ′ in these views. 
     Referring first to  FIGS. 78A and 78B , the anchor main body  401 ″ and implantation tool are shown in the condition in which it is delivered to the surgeon. As seen in  FIG. 78B , the eyelet pin  403 ′″ is in the anchor main body  401 ″ in the open position trapped between the first and second shoulders  439   a  and  439   b . As can be seen in  FIG. 78A , the gate  772  is within the skives  777  and  782  and thus prevents the anchor retention element  2501 ′ from moving longitudinally relative to the handle  564 ′. Also, the breakable cross pin  771  is intact. 
     Referring next to  FIGS. 79A and 79B , as the nut  566 ′ is turned, it advances distally within the handle  564 ′ because it is threadedly engaged to the shaft  563 ′, which is longitudinally fixed to the handle  564 ′. Thus, as the nut  566 ′ is advanced distally relative to the handle  564 ′ and shaft  563 ′, the proximal end of the rod  565 ′ abuts the breakable pin  772  so that the rod is pushed distally by the breakable pin  771  in the nut  566 ′ relative to the shaft  563 ′. Since the distal end of the rod  565 ′ abuts the proximal end of the eyelet pin  403 ′″ and the distal end of the shaft  563 ′ is fixedly attached to the anchor main body  401 ″ (via the buttons  2504  at the ends of the fingers  2503  at the distal end of the anchor retention element  2501  being engaged in the holes  2520  of the anchor main body  403 ), the eyelet pin  403 ′″ is pushed down into the closed position until it bottoms out in the bore of the anchor main body  401 ″ as seen in  FIG. 79B . 
     At this point, the eyelet pin  403 ′″ and, therefore, the rod  565 ″ cannot travel distally any farther relative to the handle  564 ′, shaft  563 ′, anchor retention element  2501 , anchor main body  401 ″, and central pin  402 ″, all of which are fixedly coupled together at this time. For instance, the anchor main body is affixed to the tool at this point by the buttons  2504  of anchor retention element  2501  that are engaged in the holes  2520  of the anchor main body  402 ′. 
     Referring now to  FIGS. 80A and 80B , since the eyelet pin  403 ′″ cannot move distally any farther, further turning of the nut  566 ′ to advance the nut  566 ′ distally along the shaft  563 ′, causes increasing force against the breakable cross pin  771  until the pin breaks, as seen in  FIG. 80A . Once the breakable pin  771  is broken, the nut  566 ′ can continue to advance distally along the shaft  563 ′ because the proximal end of the rod  565 ′ can now travel further into the distal bore of the nut past the now broken pin  771 . Referring to  FIG. 80B , note that the eyelet pin  403 ′″ is in the same position as in  FIG. 79B  since there is no place for it to go any farther. The only things that changed between  FIG. 79B  and  FIG. 80B  were the pin  771  broke and the nut  566 ′, moved distally and now contacts the annulus  775  of the cam member  773 . 
     Next, referring to  FIGS. 81A and 81B , as the nut  566 ′ continues to be turned, it continues to advance distally relative to the shaft  563 ′ now pushing the cam member  773  distally along with it. As the cam member  773  moves distally, the wedge  774  at the distal end of the cam member  773  spreads apart the arms  778  and  779  of the gate  772 , causing it to disengage from the skives  777  and  782  of the shaft and anchor retention element and expand into the slot  781  of the handle  564 ′. After the gate  772  is disengaged from the anchor retention element  2501 , the anchor retention element  2501  is finally free to translate longitudinally relative to the rest of shaft  563 ′ and the handle  564 ′. Thus, at this point, if the surgeon pulls proximally on the handle  564 ′, the handle and shaft  563 ′ will move proximally away from the anchor main body, but the anchor retention element  2501  will not move yet because its buttons  2504  are still trapped in the holes  2520  of the anchor main body  401 ″. Hence, as seen in  FIG. 80A , the anchor retention element  2501  starts to slide distally relative to the shaft  563 ′. (Of course, in actuality, it is the shaft  563 ′ and its end piece main body  2511  that are moving proximally, and not the anchor retention element  2501  that is moving distally). Referring to  FIG. 81B , once the shaft  563 ′ has been moved proximally enough that the fingers  2503  of the anchor retention element are free of the recesses  2514  in the shaft end piece main body  2511  (perhaps best seen in  FIG. 73B ), the fingers  2503  are no longer prevented from returning to their unbiased condition (i.e., with fingers  2503  bent slightly radially inwardly). Hence, the buttons  2504  disengage from the holes  2520  in the anchor main body  401 ″. Once the button  2504  are disengaged from the holes  2520 , nothing remains holding the tool to the anchor and the tool can be withdrawn. Note that, although many things are occurring in a specific sequence to release the tool from the anchor as described above in connection with  FIGS. 81A and 81B , as far as the surgeon is concerned, once he has screwed nut  566 ′ sufficiently to cause the cam member  773  to release the gate  772  from skive  782  in the anchor retention element  2501 , the anchor is free of the tool and the surgeon merely need pull the tool out. 
     Ninth Set of Exemplary Embodiments 
       FIGS. 57A-57K  illustrate another alternate set of embodiments in accordance with the present invention and including an embodiment of a suture shuttle such as the one briefly mentioned above in connection with  FIGS. 56A-56C . 
     With reference first to  FIG. 57A , an implantation tool  661  is shown bearing a bone anchor  681 . The bone anchor  681  may be substantially the same as bone anchor  581  of the embodiments discussed in connection with  FIGS. 52A-56C . The tool  661  can be considered to comprise four main parts. They are: a shaft  663  with a through bore, a handle  664  fixedly attached to the proximal end of the shaft  663 , a rod  665  extending through and slidable within the bore of the shaft  663 , and a nut  666  positioned inside a longitudinal bore  667  in the handle  664  and threaded onto the proximal end  663   a  of the shaft  663 . The distal end of the tool  661  may be substantially similar to the distal end of the tool  561  disclosed in connection with the embodiments of  FIGS. 52A-56C . The primary differences between the bone anchor and implantation tool in this embodiment relative to the embodiments of  FIGS. 52A-56C  pertain to the suture shuttle  601 . 
     In this embodiment, the shaft  663  of the tool  661  has two flat portions  694  running longitudinally along the length of the shaft and positioned 180° radially from each other around the perimeter of the shaft (only one flat portion is actually visible in  FIG. 57A ) aligned with slots  693  in the distal portion of the shaft  663  that, in turn, align with the eyelet  625  in the eyelet pin when the anchor  681  is mounted on the tool  661  similarly to the embodiments of  FIGS. 52A-56C . This configuration allows any suture or suture shuttles to pass through the eyelet in the eyelet pin without interference from the tool  661 . 
     In the illustrated embodiment, the handle  664  does not include cleats, as was the case in the embodiment of  FIGS. 52A-56C . However, the handle may include such cleats. Some surgeons may prefer cleats for temporarily securing sutures and others may not, preferring to wrap the sutures around their index fingers and pull up to tension the sutures while actuating the device to lock the sutures in the eyelet pin. In the illustrated embodiment, rather than cleats, the handle includes two large thumb rests  683 . These thumb rests provide a substantial surface on which the surgeon may place his or her thumbs to provide a purchase against which to apply the pressure to pull up on the sutures with his or her index fingers. 
     The handle  664  includes two grooves  682  aligned with the flats  694  in the shaft, which grooves may be used for retaining a suture shuttle as will be described further herein below. Two apertures  611  are positioned on each side of the handle near the handle&#39;s proximal end aligned with grooves  682 , respectively. As will become clear from the ensuing discussion, the apertures define an inner opening through the wall of the handle through which a suture may be passed and an outer surface onto which a slit in a suture shuttle may be mounted. Thus, for instance, the aperture may be as simple as a tube extending through a hole in the wall of the handle with the bore of the tube comprising the inner opening and the outer wall of the tube comprising the outer mounting surface for the suture shuttle. 
       FIG. 57B  shows an exemplary suture shuttle  601  in accordance with one embodiment. The suture shuttle may comprise a ribbon of flexible material, such as metal, particularly an alloy of nickel and titanium, Nitinol™, spring tempered steel, polymer, a woven fabric or plastic material, or any flexible member capable of performing as described. The ribbon has a first end  601   a  and a second end  601   b . A slit, hole, or other form of opening  602  (hereinafter “slit” or “opening”) is positioned in the suture shuttle  601  close to each end  601   a ,  601   b . As will become clear from the ensuing discussion, the slits  602  at each end of the suture shuttle  601  will permit sutures to be attached to one of the slits  602  in the shuttle  601 , which shuttle will be used to pass sutures through the eyelet in the eyelet pin in either direction. However, in other embodiments, a slit  602  may be provided near only one end of the shuttle. Each slit  602  is designed to have one or more of the sutures-to-be-shuttled pass there through for purposes of being shuttled through the eyelet. The entire opening may comprise a simple slit  606 , smaller in width than the diameter of a suture, such as a laser cut slit of nominal width (e.g., 0.003 in.). Particularly, as will become clear in the following discussion of the use of the implantation tool of this embodiment, one or more sutures-to-be-shuttled may be inserted through the slit while the slit  602  is held open. The slit is held open by displacing the portions  607   a ,  607   b  of the suture shuttle ribbon that are on either side of the slit  602  in a direction perpendicular to the major surface  612  of the ribbon so that they are not coplanar with each other, thus opening the slit to allow sutures to pass through (see  FIG. 57A ). 
     In at least one alternate embodiment of the slit in the suture shuttle  601  as illustrated in the top half of  FIG. 57C , the slits  602 - 1  may comprise three portions. The middle portion  603  may be an opening, such as a generally circular opening, large enough to freely accept at least one, and preferably, multiple sutures. At each end of the middle portion  603  is a narrowed portion  604 ,  605 , the width of which is less than the thickness of each suture that is to be shuttled using the suture shuttle  601 . As will be described in more detail below, sutures may be caused to enter the slit  602 - 1  relatively easily through the middle portion  603  and then tugged on to force them into the narrowed portion  604  or  605 , whereupon they will become securely longitudinally captured in the opening  602  by the edges of the slits. The sutures may be released by tugging them back down into the middle portion  603  of the slit  602 - 1 . As will become clear in the following discussion, narrowed portions  604 ,  605  also facilitate a certain type of bending or deformation of the slits for purposes of mounting the suture shuttle to the implantation tool  661  via the slits  602 - 1 . 
     In accordance with another possible alternative embodiment as illustrated in the bottom half of  FIG. 57C , the slits  602 - 2  may comprises three portions  6011 ,  6012 , and  6013 . Specifically, the middle portion  6012  may be a narrow slit portion, with slightly wider slit portions  6011  and  6013  towards either end of the slit  602 - 2 . All three portions, however, are narrower than the sutures that will be placed through the slit  60 - 2 - 2 . Preferably, the slit portions  6011  and  6013  have a length equal to or slightly less than the diameter of two sutures (e.g., sutures  991   a  and  991   b ) to better hold the sutures in the slits. Particularly, the edges of the slit bearing against the sutures helps keep the sutures from sliding out of the slit. Such a length maximizes the surface area of the sutures that it in contact with the edge of the slit. This embodiment also may decrease the possibility of the slit accidentally being ripped and also may better facilitate the bending or deformation of the slits for purposes of mounting the suture shuttle to the implantation tool  661  via the slits, as will be discussed in more detail below. 
     Different portions of the suture shuttle may be made of different materials to impart different stiffnesses as may be desirable for different applications. For instance, it may be desirable for the material properties of the suture shuttle to differ in the region of the slits as compared to the elsewhere because the inherent resilience of the slits is relied upon to secure sutures therein, whereas the rest of the suture shuttle does not need to serve such a function. Accordingly, the ends of the suture shuttle near the slits may be reinforced or made of different material than the remainder of the suture shuttle, 
     The apertures  611  positioned on each side of the handle  664  near the handle&#39;s proximal end aligned with grooves  682 , respectively, are shown in the illustrated embodiment as comprising small holes  608  in the handle near the proximal end of the handle with short tubes  609  extending there through. A diamond shaped indent  610  is formed in the handle surrounding each aperture. In other embodiments, the aperture may be entirely integral with the handle. The aperture may be round, oval, diamond shaped or otherwise. However, an aperture having an oblong shape, such as a diamond or an oval, closely emulate the shape that the openings  602  on the suture shuttle  601  will take when mounted on the aperture, as will become clear from the discussion below. Accordingly, such oblong shapes may place less stress on the material of the suture shuttle when mounted on the tool. 
     Referring again to  FIG. 57A , in the pre-surgical state, the entire implantation tool  661 , anchor  681 , and suture shuttle  601  are delivered to the surgeon preassembled. Particularly, the anchor  681  is attached to the implantation tool  661  essentially as described above in connection with the embodiments of  FIGS. 52A-56C . The suture shuttle  601  is of a length such that it may have one of its slits  601  mounted over an aperture  611  on the handle and extend from that aperture  611 , down through one groove  682  on a first side of the handle, pass over the flat portion  694  on that side of the shaft  663 , into the slot  693  on that side of the distal end of the shaft  663 , through the eyelet  625  in the eyelet pin  621  of the anchor  681  and back up through the other slot  693 , over the flat portion of  694  on the second side of the shaft  663 , through the groove  682  in the handle on the second side of the tool  600 , and up to the other aperture  611  of the tool with the other slit  602  of the suture shuttle mounted over the other aperture  611 . 
     The ends of the suture shuttle  601  adjacent the slits  602  are deformed to bend the portions  607   a ,  607   b  of the ribbon on opposite sides of the openings  602  away from each other in a direction perpendicular to the major surface  612  of the ribbon  601  so that portions  607   a ,  607   b  are not coplanar and the openings  602  are mounted on the apertures  611  in the handle. The last few millimeters of the suture shuttle  601  adjacent the ends  601   a ,  601   b  will likely twist about 90° to accommodate this deformation and mounting on the aperture  611 . 
     In the alternate embodiment of the slit  602  illustrated in  FIG. 57C  (comprising round opening portion  603  and narrow portions  604  and  605 ), if the round opening portion is designed to be only slightly smaller than the outer diameter of the tubes  609 , then the ribbon may not twist to accommodate mounting on the apertures  611 . Rather, the edges of round opening portion  603  may simply flare outwardly from the plane of the major surface  612  of the ribbon. The narrowed portion  604 ,  605  of the slit  602  help permit the flaring without damaging or permanently deforming the ribbon. 
     Since the material of the ribbon is resilient, the slits  602  want to close (i.e., return to their unstressed shape) in which the portions  607   a ,  607   b  of the ribbon on either side of the slit  602  return to the coplanar position and minimize the slit opening size. Due to this tendency, segments  607   a ,  607   b  of the suture shuttle essentially squeeze the apertures  611 , thereby relatively tightly holding the suture shuttle  601  on the apertures  611 . 
     Mounting the slits  602  over another structure, such as the tubes  609 , also prevents the edges of the slits  602  from contacting the sutures-to-be-shuttled as they are being pulled through the opening. Particularly, the edges of the slits may be sharp and could damage a suture as it is pulled through. 
     In order to facilitate the loading of sutures-to-be-shuttled through the slits  602  in the suture shuttle  601  so that such sutures may be shuttled through the eyelet of the bone anchor using the suture shuttle, one or more wire loops  620  may be disposed through the apertures  611  in the handle (and thus through the openings  602  in a suture shuttle  601  that is mounted on the apertures  611  as described above). The wire loops  620  may be closed loops (e.g., a circle of wire) as shown in the Figures or open loops (e.g., a length of suture folded over on itself). The term “wire” in the context of the wire loops use for loading sutures into a suture shuttle is being used generically. The loops  620  may be formed of any flexible material, including metal wire, suture, nylon string, etc. 
     As will be described in more detail below, any sutures  699  that are to be shuttled by the suture shuttle  601  through the eyelet  625  in the eyelet pin  621  of the anchor  681 , first must be loaded through a slit  602  in the suture shuttle. Such sutures can be passed through the portion  620   a  of a wire loop  620  extending from the outer side of the aperture  611 , as shown in  FIG. 57E . Then, while holding on to the free end  699   a  of the suture-to-be-shuttled (so that the sutures do not slide out of the wire loop  620 ), the portion  620   b  of the wire loop  620  extending from the inner side of the aperture  611  may be pulled on (see  FIG. 57F ) until the wire loop  620  is pulled completely through and out of the aperture  611  on the inner side, bringing the sutures-to-be-shuttled through the aperture  611  along with it (see  FIG. 57G ). At this point, a looped portion of each suture-to-be-shuttled  699  passes through the aperture  611  and slit  602  in the suture shuttle  601  with the free ends  699   a  of the sutures still on the outer side of the aperture  611  and slit  602 . The surgeon may now release the free ends  699   a  of the sutures-to-be-shuttled  699  and pull on the loops  699   b  of suture to bring the free ends  699   a  of the sutures-to-be-shuttled through the opening  602  as shown in  FIG. 57H . Having served its purpose, the wire loop  620  may be freed from the sutures-to-be-shuttled,  699 , and discarded. 
     In an alternate embodiment and with reference to  FIG. 67 , a threader  1301  may be employed instead of the wire loop  620 . Threader  1301  essentially comprises a rigid or semi-rigid tube or shaft  1303  with a flexible loop  1305  extending from one end. If flexible, the shaft  1303  may be formed of any flexible material such as a plastic or titanium. Likewise, loop  1305  may be formed of the same material but of thinner gauge. 
     The diameter of the shaft  1303  should be smaller than the inner diameter of the aperture  611  so that it can be passed readily through the aperture  611 . However, the loop  1305  generally should be larger than the inner diameter of the aperture  611  since its purpose is to be larger than the inner diameter of the aperture to make it easier for the surgeon to thread the sutures through loop  1305  as opposed to threading the sutures directly through the aperture  611 . The loop, being flexible, however, will collapse in on itself as it is pulled through the aperture  611 , allowing it to pass through the inner diameter of the aperture  611  while the sutures are within it. 
     In practice, the surgeon may advance the suture or sutures through the inside of the loop  1305  as illustrated in  FIG. 68A . Then, while holding onto the free ends  699   a  of the suture(s) (so that the sutures do not slide out of the loop  1305 ), the surgeon can insert the proximal end  1303   a  of the shaft  1303  into and through the aperture  611  from the outer side to the inner side as shown in  FIG. 68B  and then pull on the proximal end  1303   a  of shaft  1303  from the inner side of aperture  611  to pull the entire threader  1301  through the aperture  611  until the entire threader  1301  passes completely through the aperture  611  and out of the aperture on the inner side thereof as shown in  FIG. 68C , bringing the sutures-to-be-shuttled  699  through the aperture  611  along with it. It may be desirable for the shaft  1303  to be flexible so that it can bend if necessary to fit completely through the aperture without being blocked by another part of the tool handle. 
     The use of threader  1301  may simplify the maneuvering of the sutures by the surgeon as compared, for instance, to the embodiment illustrated in  FIGS. 57E-57G  since threader  1301  is free and separate from the tool, thereby allowing the surgeon to thread the sutures through the loop  1305  at any convenient location independently of the tool. 
     In any event, at this point and with reference to  FIG. 57I , the sutures are fully threaded through the slit  602  in the suture shuttle (and the corresponding aperture  611 ). Next, the surgeon can remove the end  601   a  or  601   b  of the suture shuttle  601  from the aperture  611  with his or her finger. The opening  602  in the suture shuttle  601  will return to its original, undeformed shape and the sutures-to-be-shuttled will be captured in the slit  602  in the suture shuttle. (In the slit embodiment of  FIG. 57B , the sutures-to-be-shuttled might not be automatically captured in the slit and might need to be pulled longitudinally into one of narrow portions  604 ,  605  to become longitudinally captured.) The free ends of the sutures-to-be-shuttled, having been attached to suture shuttle  601 , can now be pulled completely back through the aperture  611  to completely free them from the handle  664 , as shown in  FIG. 57J . 
       FIG. 57K  is a cross-sectional side view of an alternative embodiment of the proximal end of the tool  661  having a cap  622  that can be used to even further facilitate the loading of sutures-to-be-shuttled into the slits  602  of the suture shuttle  601 . This cap  621  may be silicone, rubber, or another material that can be fitted over the proximal end of the handle  664  of the implantation tool  661 . The cap  622  should be sized so as to require a minimal amount of stretching to fit over the end of the handle so that it will stay on the end of the handle by the force of friction between the outer surface of the handle and the inner surface of the cap, but be relatively easily removable by hand by a surgeon or nurse. The cap  621  has one or more wire loops  626  disposed in it that will be used similarly to the wire loops  620  in the  FIG. 57A  embodiment to facilitate the insertion of sutures into the openings  602  in the suture shuttle. In the particular embodiment illustrated in  FIG. 57D , the wire loop comprises one long closed loop of suture  626 . 
     In the illustrated embodiment, the single closed loop of suture  626  can be used to shuttle sutures through either of the two slits  602  in the suture shuttle. Particularly, loop  626  passes through one of the apertures  611  in the handle (and the associated slit  602  in the suture shuttle that is mounted on that aperture as well as through a slot  630  in the side of the cap  621  to accommodate the aperture  611 ). From there, the wire loop extends into the inside of the cap  621  up through a first hole  631  in the top of the cap, then back down through a second hole  632  in the cap, and through the other aperture  611  in the handle (including the other slit  602  in the suture shuttle that is mounted on that aperture and another slot  633  in the side of the cap  621  that accommodates that aperture  611 ). Accordingly, in appearance, the cap has two loop segments  626   a ,  626   b  extending from the cap as shown in  FIG. 57K . The pictured embodiment is merely exemplary. There may be two separate wire loops instead of one. Also, there may be one hole in the top of the cap that the loop  626  passes out of and back into. In fact, the loop need not exit the cap at the top at all. This is merely one convenient way to provide some friction between the cap  621  and the loop  626  so that the loop is relatively fixedly attach the cap and will not accidentally be pulled out of the cap when loading sutures into the apertures as described in the next paragraph. 
     Now, if suture(s)-to-be-shuttled are passed through either loop segment  626   a  or  626   b  extending from the side of the cap, then, when the cap  622  is pulled off of the top of the tool handle, the suture(s)-to-be-shuttled that are passing through one of the segments  626   a  or  626   b  of loop  626 , will be drawn through the aperture  611  in the handle (and thus through the corresponding slit  602  in the suture shuttle  601 ) essentially as described above in connection with the embodiment of  FIGS. 57A-57K . 
     Alternately, the cap may be externally or internally threaded to the top of the handle. Unscrewing the cap also will cause the suture loop to be pulled through the apertures  611 , bringing the suture(s)-to-be-shuttled through the aperture also, as previously described. 
     In operation, the suture shuttle  601  and any of the aforedescribed wire loop systems for loading sutures-to-be-shuttled into the slits  602  in the suture shuttle  601  facilitates ease of use of the implantation system. Particularly, in an exemplary arthroscopic procedure, the bone anchor  681  and implantation tool  661  may be inserted into the patient through a cannula and an incision in the patient&#39;s body. The anchor is fixed to bone as previously described in connection with any of the embodiments in this application. Then, through techniques well known in the art and/or disclosed in this application, sutures are brought up through the same cannula in which the implantation tool is inserted. The sutures may, for instance, be coupled to tissue (either directly or via one of the tissue fastener devices  2  disclosed in this specification), such as a rotator cuff that needs to be re-attached to the humerus bone via the bone anchor  681 . In any event, the sutures are brought up through the cannula and inserted through one of the openings  602  in the suture shuttle  601 , such as in any one of the manners described hereinabove using wire loop  620  or  626  and/or the cap  621 . The sutures are longitudinally captured in place in the opening  602  (again such as in any of the ways previously described hereinabove). 
     Next, the end (e.g.,  601   a ) of the suture shuttle  601  bearing the suture(s)-to-be-shuttled is removed from the aperture  611 . The opposite end (e.g.,  601   b ) of the suture shuttle also is removed from of its aperture  611 . The suture shuttle  601  is now ready for deployment to draw the suture(s)-to-be-shuttled through the eyelet in the eyelet pin of the bone anchor  681 . Particularly, the surgeon now pulls proximally on the end  601   b  of the suture shuttle opposite the end  601   a  in which the suture(s)-to-be-shuttled have been inserted. This, of course, draws the end  601   a  of the suture shuttle within which the sutures-to-be-shuttled are fixed down along the length of the tool handle  664  and tool shaft  663 , through the eyelet in the eyelet pin, and back up along the diametrically opposite side of the tool shaft  663  and handle  664 , carrying the suture(s)-to-be-shuttled with it. (Note that the suture shuttle also may be use to shuttle sutures from outside the body through the eyelet of the anchor in essentially the same manner for different procedures.) In fact, the suture shuttles described herein may be used for generally any type of suture shuttling or suture passing and is not limited to use with the tools described herein. Furthermore, it is not limited to uses involving the shuttling of sutures. It may be used to grasp and/or shuttle tendons, ligaments or any other generally longitudinal anatomical members. Because the suture shuttle can be made of a resilient material with some stiffness, such as Nitinol™, the suture shuttle, including the slits, may be fabricated to have an unbiased shape of any configuration that may be desirable for its particular purpose. Thus, in one alternate embodiment, the suture shuttle may be fabricated such that the slit or slits are normally open rather than closed when unbiased and can be biased closed as needed. For instance, such a suture shuttle may be provided within a tube, such as a catheter. When the shuttle needs to accept a suture through the slit, the end of the shuttle bearing the slit is extended from the end of the catheter so that the slit may rebound to its unbiased open position. After the suture is passed through the open slit, the shuttle may be retracted into the catheter, the lumen of the catheter shaped so that, when the slit is retracted within the catheter, the inner wall of the catheter lumen biases the slit closed, trapping the suture in the slit. 
     Furthermore, according to another alternate embodiment, it has been found that fabricating a slight curvature into the longitudinal ends of the suture shuttle (the radius of the curve being perpendicular to the major surface  612 ) while leaving the majority of the shuttle between the two ends straight facilitates the ease of pulling the suture shuttle through the eyelet. In one exemplary implementation, the entire suture shuttle is 572 mm long, the slits are 9 mm long and start 2 mm from the ends of the shuttle and the last 1.8 mm of each end of the shuttle is imparted with a curvature of radius 2 mm. Accordingly, in this embodiment, almost the entire length of the shuttle, including the slits, is flat and only the very ends (laterally outwardly of the slits) is curved. 
     In yet other embodiments, multiple suture shuttles may be mounted to the tool simultaneously to permit multiple sets of sutures to be shuttled through the eyelet at different times or locations. In fact, a plurality of eyelets may be provided in an eyelet pin and a plurality of suture shuttles may be mounted on the tool passing through the plurality of different eyelets. 
     Additionally, because the suture shuttle is in the form of a ribbon (i.e., has major surface  612  and a much thinner depth perpendicular to the major surface as well as has a stiffness), the suture shuttle as well as the sutures trapped in it will travel down the one side of the instrument, through the eyelet and back up the other side without any twisting about the longitudinal axis of the shuttle. Thus, the suture shuttle tracks smoothly and easily through the eyelet and the sutures do not twist around each other. A problem with some conventional suture shuttles made of braided filaments is that they tend to twist as they pass through a restricted passageway, such as the eyelet. The smaller the pitch of the braid, the more it tends to twist. This causes the sutures being shuttled to also twist around themselves, which can cause the sutures shuttled to bunch up where they are trapped in the slit of the suture shuttle so as to increase the cross section of the suture material that must pass through the eyelet, impeding smooth passage of the sutures and suture shuttle through the eyelet. 
     The aspect ratio of the width of the shuttle (e.g., left to right in  FIGS. 57B and 57C ) being much greater than its thickness or depth (e.g., into and out of the page in  FIGS. 57A and 57B ) is important to the performance of the shuttle. Particularly, the shuttle is resilient but relatively flexible parallel to its thickness, relatively stiff parallel to its width, and relatively resistant to twisting about its longitudinal axis (although, as mentioned above, it must be twisted about 90° to mount the slits over the apertures of the handle). The relative high flexibility parallel to its thickness is what allows it to bend and track easily down one side of the tool, through the eyelet, and up the other side. Its relative stiffness parallel to its major surface  612  keeps the shuttle in line with the tool. Finally, the resistance to twisting about its longitudinal axis keeps the shuttled sutures from twisting around themselves and/or the shuttle and bunching up as they are being shuttled. 
     In one embodiment, the suture shuttle is formed of NiTinol™ and is 0.25 mm thick and 1.5 mm wide, giving it an aspect ratio of about 6:1, which has been found to be quite suitable for this particular application. Preferably, the edges of the shuttle are rounded to prevent the person handling the suture shuttle from cutting his or her gloves or hands on any sharp edges. 
     With reference to  FIG. 57J , it should be apparent that, in the illustrated configuration, when the suture shuttle is pulled to shuttle the sutures  699  through the eyelet, the distal ends  699   a  of the sutures will pass through the eyelet above the suture shuttle and the loop portion of the sutures will be below the ribbon. Some surgeons prefer to have the distal (free) ends of the sutures pass through the eyelet below the sutures shuttle and the attached ends above the suture shuttle. It is believed that this results in lower shuttling force, thereby facilitating the ease with which the sutures pass through the eyelet. The distal ends of the sutures can be made to pass through the eyelet above or below the sutures shuttle by virtue of selecting how the slit of the suture shuttle is mounted over the aperture  611 . Particularly, as previously described, the suture shuttle must undergo a 90° twist near end of the shuttle adjacent the slit in order to allow the slit to be mounted over the aperture. Looking down from above on the end of the shuttle, this twist may be clockwise or counterclockwise. Likewise, after the twisting, when spreading open the slit to mount it over the aperture, there are two ways to spread open the slit. Particularly, looking down the barrel of the aperture from outside the tool, the portion of the shuttle on either side of the slit  607   a  or  607  ( FIG. 57B ) that is closer to the handle of the tool (i.e., the radially inward portion  6007   a  or  607   b ) may be spread to the right (while the radially outward portion  607   b  or  607   a ) is spread to the left or vice versa. 
     Hence there are four permutations of how the each slit may be mounted over the corresponding aperture, namely, (1) clockwise-twisted/inner portion  607  to the right, (2) clockwise-twisted/inner portion  607  to the left, (3) counterclockwise-twisted, inner portion  607  to the right, and (4) counterclockwise-twisted, inner portion  607  to the left. Of course, when the suture shuttle is released from the aperture, the shuttle and slit will return to their unbiased configurations with no twist and with the both portions  607   a  and  607   b  coplanar and with the distal ends of the sutures trapped in the slits either facing outwardly of the handle or inwardly of the handle. It should be apparent that, when the distal ends  699   a  of the sutures  699  face outwardly, they will pass through the eyelet below the shuttle and, when they face inwardly, they will pass through the eyelet above the shuttle. Two of these mounting options will result in the sutures passing through the eyelet with their distal ends  699   a  below the shuttle and two will result in the sutures passing through the eyelet with their distal ends  699   a  above the shuttle. More particularly, clockwise-twisted/inner-portion-right and counterclockwise-twisted/inner-portion-left will result in the distal ends  699   a  of the sutures facing outwardly from the handle and hence passing through the eyelet below the suture shuttle. 
     Those sutures are now through the eyelet in the bone anchor  681  and extending out of the patient&#39;s body. The surgeon can now release the sutures from the slit  602  in the suture shuttle  601 . The manner in which the surgeon releases the sutures from the slit  602  in the suture shuttle may vary depending on the surgeon and/or the particular embodiment of the suture shuttle. For instance, in the exemplary embodiment of  FIG. 57B , in which the suture shuttle opening comprises a middle section  603  that is larger than the diameter of the suture, the surgeon can merely push or pull on the sutures to force them out of the narrow slit  604  or  605  of the slit  602  and into the larger middle portion  603  of the slit and then pull them through until they are free of the slit  602 . Alternately and particularly in the embodiment of  FIG. 57A , in which the slit  602  is just a laser etched slit, the surgeon can simply cut the suture(s) and discard the suture shuttle  601  along with the end(s) of the suture(s) that are still trapped in the slit  602 . 
     In any event, now the surgeon may pull the desired tension on the sutures to draw the soft tissue onto the bone surface adjacent the bone anchor  681 , and then deploy the eyelet pin  621  to the closed position as previously described to lock the sutures in the bone anchor. 
       FIG. 58  is a close-up view of the slit  602  of the suture shuttle  601  passing through the eyelet  625  in the eyelet pin  621  during suture shuttling carrying two sutures  685  and  686 . The eyelet  625  has a widened, ribbon-guiding portion  625   a  adapted to accept the suture shuttle ribbon  601  in a certain orientation. With reference to  FIG. 58 , an advantage of this embodiment is that the use of a flat ribbon as the suture shuttle  601  and an appropriately sized and shaped eyelet  625  relative to the width of the ribbon  601  guarantees that the ribbon  601  will pass through the eyelet  625  in a certain orientation and position (as shown in  FIG. 58 , e.g., with its width dimension, w, oriented horizontally relative to the bone anchor). The advantage of this is that the sutures  685 ,  686  that are fixed in the slit  602  are therefore guaranteed to pass through the eyelet  625  in the orientation shown in  FIG. 58 , namely, with the plurality of suture segments neatly stacked in the vertical dimension, V. It should be remembered that each suture captured in the slit  602  of the suture shuttle will be folded over on itself about the suture shuttle  601  as it passes through the eyelet. Thus, each individual suture actually passes through the eyelet  625  with one segment  685   a ,  686   a  of the suture above the ribbon  601  and one segment  685   b ,  686   b  below the ribbon  601 . Thus, for instance, if two sutures are being shuttled, as shown, the eyelet  625  must accommodate four suture diameters in the vertical dimension, v. This configuration helps keep the sutures-to-be-shuttled  685 ,  686  from getting caught or binding as they pass through the eyelet  625 . 
     As illustrated in  FIG. 59 , the shaft  663  of the insertion tool  661  may be pre-surgically encased in a plastic sheath  696  in order to protect the tool shaft and other components and keep them organized during the surgical procedure. The sheath  696  may run from the proximal end of the anchor  681  all the way up to the distal end of the handle  664 . The sheath can remain in place until the suture shuttle is ready to be deployed. The use of the sheath is advantageous as these procedures are usually performed arthroscopically through surgical ports. One can readily imagine that, if the sheath was not in place, while driving the anchor, the ribbon  601  may get caught up in either the surgical port or the tissue of the patient. 
     The sheath  693  may be formed to make it easily tearable for removal during the procedure. For instance, in one exemplary embodiment, the sheath  693  has two weakened strips  697   a ,  697   b  (of which only one is visible in the figure) running longitudinally along the sheath and diametrically opposed from each other. The weakened portion, for instance, may comprise portions of the sheath that are thinner than the remainder of the sheath. The sheath  696  also may include tabs  695   a ,  695   b  at the proximal end to permit easy grasping of the two sides of the sheath for tearing. By grasping the tabs  695   a ,  695   b  and pulling them away from each other in the direction transverse to the longitudinal axis of the tool  661 , the sheath can be caused to tear away longitudinally at the two weakened sections  697   a ,  697   b . If the surgeon either pulls upwardly as he is tearing or keeps his hand stationary in the longitudinal direction of the tool, then the sheath will simple slide upwardly along the shaft as it is torn. 
     It may be useful to permit slack in the suture shuttle for purposes of loading the suture shuttle  601  onto the apertures  611  in the handle  664 . Particularly, if the suture shuttle is under tension, then it is more difficult to open the slits  602  for mounting on the apertures  611 . However, after the suture shuttle is mounted on the apertures, slack is undesirable because it would cause the suture shuttle to bow outwardly from the tool shaft  663 . Accordingly, providing the apertures on a spring-biased carriage in the handle would allow the carriage to be forced distally against the spring bias during assembly so that the openings on the suture shuttle can be mounted on the apertures  611  while there is slack in the suture shuttle  601 . Then, when the force on the carriage is released, the spring will bias the carriage proximally along the handle  664 , thus taking up any slack in the suture shuttle  601 . 
     In accordance with one embodiment (not shown), one or more portions of the handle bearing the aperture  611  may be slidably mounted on a spring-loaded carriage relative to the rest of the handle. For instance, the carriage(s) may be mounted on rails in a slot in the handle and biased proximally by a spring. However, it can be forced distally within the slot. 
       FIGS. 60A-60C  illustrate an alternate embodiment of the proximal portion of an implantation tool  661   b  that provides both (1) an alternate suture loading mechanism that can provide slack in the suture shuttle  601  for purposes of loading the suture shuttle onto the apertures  711  and then taking up that slack after mounting and (2) a simple mechanism for releasing the suture shuttle from the apertures. This embodiment may include a cap such as cap  622 , and/or one or more wire loop such as wire loops  620  or  626 , for loading suture(s)-to-be-shuttled through the aperture  711  of this embodiment. However, these components are not shown in order not to obfuscate the features of interest on this embodiment.  FIG. 60A  is a perspective view of the handle  764  with the handle shown in see-through so as to permit viewing of the components inside the handle. The components inside the handle may be essentially identical to the components in the embodiments of  FIGS. 57A-57K . In this embodiment, the apertures comprise part of a clip  742  mounted on the proximal end of the handle  764 . Particularly, the clip includes two tubes  711  which serve as the apertures upon which the slits  602  of the suture shuttle are mounted. The clip may further include a lever portion  743  comprising two legs  743   a ,  743   b  and a gripping portion  744 . In the particular embodiment illustrated in these figures, the apertures  711  are integral with the lever portion  743  and grasping portion  744  to form the overall clip  742 . In fact, the entire assembly may comprise one wire form. The wire form is resilient in that the opposing ends of the wire form where the apertures  711  are may be squeezed inwardly towards each other in the direction of arrows j. The apertures  711  are mounted within vertically oriented slots  750  at the proximal end of the tool handle  764 . Accordingly, the clip  742  can translate vertically relative to the tool handle with the apertures  711  sliding within the slots  750  in the handle. 
     The top of the handle (i.e., its proximal end) is shaped so as to provide cam surfaces  751 ,  752  for the legs  743   a ,  743   b  of the clip  742 . The cam surfaces  751 ,  752  essentially comprise the edges of a generally U or V-shaped notch  753  in the sidewall  754  of the handle adjacent and open to the proximal end of the handle. In this particular embodiment, a generally rectangular opening  755  also is provided in the side surface of the handle opposite the U or V-shaped notch  753  open to the proximal end of the handle in order to provide clearance for the two legs  743   a ,  743   b  of the clip (without squeezing them together). The cam surfaces  751 ,  752  will force legs  743   a ,  743   b  inwardly toward each other if the clip is rotated about the axis k defined by the apertures  711  to cause the legs to ride on the cam surfaces  751 ,  752 . Sutures-to-be-shuttled may be passed through the slit  602  in the suture shuttle and the aperture  711  on the handle using wire loops in the manner previously described in connection with the embodiments of  FIGS. 56A-56K . 
     This design provides a mechanism for permitting slack in the suture shuttle  601  during loading of the suture shuttle on the apertures  711  and then taking up that slack. Particularly, as previously described in connection with the various embodiments of  FIGS. 52A-58 , nut  566  in  FIGS. 54A ,  54 B,  55 A, and  55 B can be caused to travel longitudinally relative to the shaft  563  and handle  664  by the action of the mating screw threads on the shaft  563  and nut  566 , respectively, as the nut is rotated. During loading of the suture shuttle  601  onto the apertures  711 , the nut  566  may be positioned in the lowest (i.e., distal-most) position possible without driving the eyelet pin into the anchor main body and over the central pin. With reference to  FIGS. 54A ,  54 B,  55 A, and  55 B, this, for instance, would be the position where the distal bore  570  of the nut is abutting the proximal end  565   a  of the rod  565  and the distal end  565   b  of the rod  565  is abutting the proximal end of the eyelet pin  521  but there is no force applied on the eyelet pin by the rod  565 . The relative length of the tool and the suture shuttle  601  can be selected so that, when the apertures  711  are in this position, there is sufficient slack in the suture shuttle  601  to allow easy mounting of the suture shuttle  601  on the apertures  711 . 
     Then, after the suture shuttle is mounted on the apertures, the nut  566  can be rotated counterclockwise (assuming right handed threads) to move the nut proximally. The proximal end of the nut  566  will push the apertures  711  proximally in their slots  750 . The nut  566  can be moved longitudinally a distance to take up all of the unnecessary slack in the suture shuttle  601 . Thereafter, the nut can be left in that position so that the apertures  711  cannot move back down distally. The tension in the suture shuttle itself will keep the apertures  711  from moving further proximally. This is the position shown in  FIG. 60A . 
     Referring now to  FIG. 60B , suture(s)-to-be-shuttled  776  may be loaded through the slot  602  in the suture shuttle  601  and the apertures in any of the manners described in connection with any of the previously described embodiments. When it is time to release the suture shuttle  601  from the handle  764  (i.e., after the shuttle has been loaded with one or more sutures-to-be-shuttled  776 ), the surgeon may grasp the gripping portion  744  of the clip  742  and rotate the clip about its pivot axis K defined by the longitudinal axes of the apertures  711 . Eventually, the legs  743   a ,  743   b  will reach the cam surfaces  751 ,  752  and start riding against them as shown in  FIG. 60B . 
     Referring now to  FIG. 60C , as the legs  743   a ,  743   b  of the lever portion  743  ride against the cam surfaces  751 ,  752 , they will be forced toward each other, causing the apertures  711  to approximate each other and eventually become free of the slot  750  (this is the position shown in  FIG. 60C ) so that the clip  742  is released from the handle  764  and can be removed. Thus, in this particular embodiment, rather than removing the slits  602  in the suture shuttle  601  from the apertures  711  in order to release the suture shuttle from the handle, instead, the apertures  711  are removed from the slits  602 , thereby releasing the suture shuttle  601  from the handle  764 . 
     Once the clip  742  is separated from the handle  764  (by removing the apertures  711  from the slots 750 ), the free ends of the suture(s)-to-be-shuttled  776  are pulled back through the pass-through  711  and slot  750 , thus releasing them from the pass-through. 
       FIGS. 61A and 61B  illustrate another alternate embodiment of the proximal portion of the implantation tool that offers another way to release the suture shuttle from the apertures. This embodiment is substantially similar to the embodiment described above in connection with  FIGS. 60A-60C . In this embodiment, slack can be provided in the suture shuttle or purposes of loading it on the apertures and then that slack can be taken up by rotation of the nut essentially in the same way as described in connection with the embodiment of  FIGS. 60A-60C . However, the clip bearing the apertures has been replaced with a single tube as described in detail below. 
       FIG. 61A  shows the tool in its pre-surgical condition and  FIG. 61B  shows the tool in the condition it would appear when the suture shuttle  601  is in the process of being dismounted from the apertures. Most of the components of the tool may remain that same as in the embodiments of  FIGS. 57A-57K  and/or  60 A- 60 C and such components have been labeled with the same reference numerals in  FIGS. 61A and 61B . 
     With reference first to  FIG. 61A , in this embodiment, a hollow tube  870  that runs between the two opposed windows  750  in the handle  764  of the tool serves as both apertures. 
     The tube comprises a passageway  871  running the entire length of the tube from opening  872  at one end  870   a  to opening  873  at the other end  870   b . Intermediate the two ends of the tube is at least one lateral opening in the side wall of the tube. In the illustrated embodiment the opening comprises a single opening  847  approximately half way between the two ends of the tube. However, this is merely exemplary. In other embodiments, the opening may, for instance, comprise two openings, a first opening near the first end  870   a  and positioned so that it is inside of the body of the handle  764  and a second opening near the second end  870   b  of the tube  870  and positioned so that it also is inside of the body of the handle  764  when the tube  870  is mounted on the handle of the tool. 
     In any event, the lateral opening  847  serves several functions. First, two wire loops  876   a ,  876   b  that will be used to pull suture(s)-to-be-shuttled through the apertures are pre-surgically positioned in the tube  870  as shown in  FIG. 60A . Specifically, each wire loop extends between the lateral opening  847  and one of the openings  872  or  873  in the ends of the tube. Thus, in essence, the portion  870   c  of the tube  870  between lateral opening  847  and end  870   a  may be considered to be one of the apertures and the portion  870   d  of the tube  870  between lateral opening  847  and end opening  873  may be considered to be the other of the apertures. In the pre-surgical condition ( FIG. 60A ), the wire loops  876  extend beyond the openings  872 ,  873  in the ends of the tube  870  so that suture(s)-to-be-shuttled may be passed through them for purposes of loading the sutures into the slits  602  of the suture shuttle  601  and apertures  870   c ,  870   d  in the same manner as described in connection with the embodiment of  FIGS. 60A-60C , for instance. 
     The lateral opening  847  also serves the function of providing a weakened section  890  of the tube  870  about which the tube can fold or bend upon application of sufficient force so that the tube  870  may be removed from tool handle  764  thereby releasing the suture shuttle  601  from the apertures  870   c ,  870   d , as will be described in more detail below. In this embodiment, a sufficient portion of the side wall of the tube is removed to from the lateral opening  847  so that the tube  870  will bend upon an application of a predetermined lateral force of about 2 pounds. This predetermined bending force may be designed into the tube by appropriate selection of wall thickness of the tube, amount of material removed to form the opening  847 , and/or thinning the wall of the remaining portion or the tube adjacent the opening  847  (such as by etching a groove therein). 
     It should be apparent that, pre-surgically, the tube  870  is trapped in the handle  764  by virtue of the tube being longer than the distance between the two windows  750  in the handle. It also should be apparent that the tube  870  can be acted upon by the nut  566  to push the tube proximally within the windows  750  to take up slack in the suture shuttle  601  essentially exactly as described above with respect to the apertures  711  in the embodiment of  FIGS. 60A-60C . 
     In one embodiment, the wire loops  872  and  873  are attached to another wire  880  that is disposed in the tube  870  in the pre-surgical condition. In this embodiment, the wire loops  872 ,  873  are attached to the wire  880  about half way between the two ends  881 ,  882  of the wire  880 . The proximal end  881  of the wire  880  extends out of the lateral opening  847  in the tube so that a surgeon can grasp it and pull on it to draw the wire loops  872 ,  873  through the aperture portions  870   c  and  870   d  of the tube and out of the lateral opening  847  carrying the suture(s)-to-be-shuttled with them, thereby loading the suture(s)-to-be-shuttled onto a slit  602  in the suture shuttle  601  essentially as previously described in connection with various above-discussed embodiments. A ball  888  or other device may be attached to the proximal end  881  of the wire  880  to facilitate grasping by the surgeon. 
     The distal end  882  of the wire  880  is designed so that the distal end of the wire  880  is attached to the tube  870  and cannot be being removed from the tube  870 . This attachment may take a variety of forms. In one embodiment, the distal and  882  of the wire  880  may be welded, adhered, or otherwise attached to the tube  870 . In the illustrated embodiment, however, the distal end  882  of the wire  880  actually passes through a hole  885  in the tube  870  that is positioned substantially opposite to the lateral opening  847  and has a blocking member  884 , such as a ball or pin attached to distal end  882  that cannot pass through the hole  885 . 
       FIG. 61B  shows the tool handle after two sutures-to-be-shuttled  891 ,  892  have been loaded through the aperture  870   c  and slit  602 . Thus, after the wire loops and suture(s)-to-be-shuttled have been loaded through the aperture portion  870   c  or  870   d  and out of the lateral opening  847 , the surgeon continues to pull on the proximal end  881  of the wire  880  with enough force to bring the wire  880  to tension (because the distal end  882  of the wire  880  is attached to the tube  870 ) and bend the tube  870  at the weakened section  890  adjacent lateral opening  847 . When the tube  870  bends at section  888 , the two ends  870   a ,  870   b  of the tube move laterally toward each other, thereby pulling the ends  870   a ,  870   b  free of the windows  750  in the tool handle  764  (and, hence, also free of the slits  602  in the suture shuttle  601 ). Hence, the suture shuttle  601  is released from the tool handle  764  and, simultaneously, the tube  870  is removed from the tool handle  764 . 
     Although not illustrated in the Figures, as the tube  870  is further removed from the handle  764 , the suture(s)-to-be-shuttled  891 ,  892  continue to simply slide through the tube  870   a  or  870   b  and become free of the tube  870  (while remaining loaded in the slit  602  of the suture shuttle  601 , which closes once the tube  870  is pulled free of the slit  602 ). 
     The wire loops  876   a ,  876   b  should be attached to the wire  880  at a point  889  along the wire  880  so that there is enough of wire  880  distal of the attachment point  889  to allow the wire loops  876   a ,  876   b  attached to the wire  880  at point  889  to be pulled completely through and out of lateral opening  847  before the wire  880  is fully extended under tension. This is because the wire loops  876   a ,  876   b  and suture(s)-to-be-shuttled  891 ,  892  should be completely loaded through the aperture  870   c  or  870   d  before the tube is bent to release the shuttle  601  from the aperture. 
       FIG. 61C  shows yet another embodiment of the proximal portion of the implantation tool that offers another way to release the suture shuttle from the apertures. In this embodiment, two slots  951  open to the proximal end of the tool are positioned diametrically opposite to each other with an insert  952  running laterally between and in a friction fit with the slots  951 . The insert  952  has a channel structure  953  extending laterally from each side through the slots  951  in the handle (only one channel structure  953  can be seen in the view of  FIG. 61C ). The channel structure has a side opening  954  at its top, thus defining an open channel  955  in the tube (rather than a radially closed bore). The outer surface of the channel structures  953  are used to hold the slits  602  in the suture shuttle  601  open as substantially described above in connection with the embodiments of  FIGS. 57A-61B . With this embodiment, the surgeon will manually insert the sutures into the channels  955  and, thus, through the open slit  602  of the suture shuttle  601 . Next the suture shuttle can be released from the channel structure  953  by simply pulling up and/or radially outward of the tool on the suture ends. This will cause the sutures to move through the opening  954  in cylinder  953  of insert  952  and bear on the edge of opening  602  in suture shuttle  601  and pull the suture shuttle  601  off of the channel structure  953 . The other side of the suture shuttle may be released essentially as described previously in connection with the embodiment of  FIGS. 57A-57J . Finally, the surgeon can pull the insert  952  out of the handle through the open ends of the slots  951 , such as by grasping it with a hemostat or the like and pulling upward to provide access to the nut inside the handle. 
     Also, note another feature of this embodiment is a variation of the thumb rests  966  (as compared to the embodiment of  FIGS. 57A-57K , for instance). Thumb rests  966  are larger and present a larger, more laterally oriented top surface with gripping ridges  967  in order to offer the surgeon an enhanced surface for resting his or her thumbs when tensioning the suture just prior to locking the sutures in the anchor, as previously described. 
       FIGS. 69A-69H  illustrate an alternate embodiment of the implantation tool in which the suture shuttle is reduced in length so that the longitudinal ends of the suture shuttle and the shuttle-mounting apertures are located at the distal end of the handle of the tool, rather than at the proximal end. There are several advantages to this embodiment. First, it keeps the suture shuttle away from the majority of the handle, where the surgeon or other surgical staff will be holding the tool and could accidentally knock the shuttle off of its aperture mounts. More significantly, the process of knotting the sutures to the tissue before shuttling the sutures through the eyelet of the bone anchor and locking them in place is a rather tedious procedure which often ends up with the various suture ends that pass through the eyelet being of significantly different lengths. The shortest suture end, for instance, may be a foot shorter than the longest suture end protruding from the arthroscopic cannula through with the surgery is being performed. The surgeon is at the mercy of the shortest suture after the knotting procedure in terms of threading the suture ends through the slits in the suture shuttle. Occasionally, it is found that the shortest suture is not long enough to reach the proximal end of the handle. Accordingly, it is advantageous to move the longitudinal ends of the suture shuttle where the slits that must receive the suture ends are positioned as distally as possible on the handle. 
       FIG. 69A  is a perspective view of an embodiment of the tool  1310  having suture loading near the distal end of the handle  1312 , rather than near the proximal end of the handle.  FIG. 69B  is a perspective view of the threader member  1316  of the tool of  FIG. 69A .  FIG. 69C  is a perspective view of the aperture member  1314  of the tool of  FIG. 69A .  FIG. 69D  is a perspective view of the threader member  1316  assembled to the aperture member  1314  as it would be when the tool is assembled in its pre-surgical condition (but disembodied from the tool  1310 ).  FIG. 69E  is a close up view of the distal portion of the handle  1312  of the tool  1310  in the fully assembled, pre-surgical state.  FIG. 69F  is a cross-sectional view through section F-F in  FIG. 69E .  FIG. 69G  is a perspective view of the handle  1312  after the threader member  1316  has been withdrawn.  FIG. 69H  is a perspective view of the distal portion of the handle  1312  after the aperture member  1314  has been withdrawn. 
     The basic structure and operation of this embodiment of the implantation tool is similar to the ones previously described in that apertures  1320  on the aperture member  1314  hold open the slits  1333  in the suture shuttle  1321  and the sutures to be shuttled are passed through one of the loops  1322  of threader member  1316 , which loops are then pulled through the apertures  1320  in order to carry the sutures through the apertures. Then, as previously described, the suture shuttle  1321  will be removed from the apertures  1320 , allowing the slits  1333  to close, thereby firmly holding the sutures in them and releasing the suture shuttle from the handle. 
     More specifically, the loops  1322  are provided on a threader member  1316  (see  FIG. 69B ), which is separable from an aperture member  1314  (see  FIG. 69C ), which itself is separable from the handle  1312 . 
     With reference to  FIG. 69B , the threader member  1316  comprises two tubes or shafts  1330 , each with a semi-rigid wire loop  1322  extending from its distal end, very similarly to the threader illustrated in  FIG. 67 . The proximal ends of the shafts  1330  are attached to a handle portion  1332 , including a finger grip  1325 . 
     The aperture member  1314  is shown in  FIG. 69C . It comprises a transverse member  1319  with two lever members  1326  connected by the transverse member  1324 . It further comprises two tubes  1320 . The two tubes  1320  of the aperture member  1314  are the apertures that hold the slits  1333  of the suture shuttle  1321  open (see, e.g.,  FIGS. 69E and 69F ) as previously described in connection with earlier embodiments. Two legs  1318  extend from transverse member  1319  in the opposite direction of lever members  1326 . Also, a hinge  1324  is disposed in the middle of the transverse member  1324  between the two legs  1318 , which hinge  1324  permits the transverse member to be flexed thereabout responsive to the two lever members  1326  being squeezed toward each other under finger pressure. This flexing about hinge  1324 , consequently, causes the distal ends of legs  1318 , which bear dogs  1321 , to spread apart to release the operative member  1314  from the handle  1312 , as will be described in more detail below. 
       FIG. 69D  shows how the threader member  1316  and the aperture member  1314  are assembled to each other in the fully assembled condition (but disembodied from the tool handle for clarity), while  FIG. 69E  is a close up of the assembled threader member  1316  and aperture member  1314  as they are assembled to the handle  1312 . Particularly, it can be seen that the threader member  1316  is assembled to the aperture member  1314  with the shafts  1330  of the threader member  1316  passing through the tubes  1320  of the aperture member  1314  such that the loops  1322  of the threader member  1316  extend from one side of the tubes  1320  of the aperture member  1314  and the handle portion  1324  of the threader member  1314  extends from the other ends of the tubes  1320  of the aperture member  1314 . With the threader member  1316  assembled to the aperture member  1314  as shown in  FIGS. 69D and 69E , the inner surfaces  1333  of the lever members  1326  of the aperture member  1314  rest against the edges  1332  of the threader member  1316  such that the finger rests  1326  cannot be squeezed towards each other because they are blocked by the edges  1332  of the threader member  1316 . 
     As can be best seen in  FIG. 69F , when the instrument  1310  is fully assembled and the lever members  1326  are in the unbiased position, the dogs  1321  at the ends of legs  1318  of the aperture member  1314  rest against shoulders  1317  on the handle  1312  such that the aperture member  1314  cannot be pulled out laterally from the handle  1312  unless the lever members  1326  are squeezed towards each other, causing the dogs  1321  to spread away from each other and thus become clear of the shoulders  1353  of the handle  1312 . 
     Thus, in operation, the surgeon advances the sutures to be shuttled through one of the loops  1322  of the threader member  1316 . In an alternate embodiment, the two loops  1322  may be offset from each other in the longitudinal direction of the tool  1310 , such as illustrated in  FIG. 69I . Because the loops are not laterally aligned with each other in this configuration, it reduces the likelihood of inadvertently loading the sutures through both loops  1322  simultaneously. 
     Then, the surgeon may hold the free ends of the sutures as described in connection with previously described embodiments, while grasping the finger grip  1325  of the threader member  1316  and pulling on it so as to pull the loops  1322  on the threader member  1316  through the apertures  1320  of the aperture member  1314 , thereby carrying the sutures through the tube  1320  similarly to the way described in connection with previous embodiments. The semi-rigid loops  1322  will collapse in on themselves to squeeze through the tubes  1320 . 
     Alternately, wire loops  1322  include suture lock  1326  at their far ends that the surgeon may slide the sutures into so that he/she does not have to hold on to the free ends of the sutures when pulling the threader member  1316  through the aperture member  1314 . More particularly, the main part of the wire loop  1322  forms a large passage so that the surgeon can easily thread the sutures into and through the loops  1322  as previously discussed. But the loops  1322  also include small suture locks  1326  in the form of a slit so that, after the sutures are through the loop  1322 , they may be slid laterally into the suture lock  1326 , which will hold the sutures in the loop  1322  thus freeing up one of the surgeon&#39;s hands from having to hold onto the free ends of the sutures in order to assure that the sutures do not fall out of the loop when the loop is pulled through the tube  1320  of the aperture member  1314 . After the loops  1322  have been pulled through the tubes  1320 , the surgeon simply slides the sutures laterally back out into the main portion of the wire loop  1322  for removal from the threader member  1316 . 
     In one embodiment the slits of the locks  1326  are smaller than the diameters of the sutures in the unstressed condition so that the resilience of the wire loop material will snag and hold the sutures within the suture lock. However, the slit may actually be slightly larger than the combined diameters of the two sutures that it will hold. Particularly, it has been determined that, as long as the slit is approximately the same size as the sutures within it, the sutures will not slip out of the suture lock  1326  during passage through the tubes  1320 . Further, in this embodiment, the sutures do not need to be slid laterally out of the suture lock back into the main portion of the wire loops  1322  after the sutures have been transported through the tubes  1320 , but can be pulled longitudinally directly out of the suture lock without damaging the sutures. 
     After the threader member  1316  has been withdrawn as shown in  FIG. 69G , the surgeon can then squeeze the lever members  1326  toward each other thereby spreading the dogs  1321  at the ends of legs  1318  apart from each other and free of the shoulders  1353  of the handle  1312  (see  FIG. 69F ) so that the aperture member  1314  can now also be withdrawn from the handle  1312  to release the suture shuttle  1323  from the tubes  1320 , as shown in  FIG. 69H . More particularly, this will cause the slits  1333  to slide off of the tubes  1320 , thereby allowing the slits  1333  to close and firmly grasp the sutures that had been passed through one of the tubes  1320  in the closed slit. 
     At this point, the suture shuttle  1323  can then be used to shuttle the sutures through the eyelet pin as described in connection with previously embodiments. 
     In yet another embodiment (not illustrated), largely similar to the embodiment of  FIGS. 69A-69H , the dogs  1321   a  at the ends of legs  1318  on aperture member  1314  still rest against shoulders  1353  on the handle  1312  to hold the aperture member  1314   a  to the handle  1312   a . However, in this embodiment, there is no need to squeeze any lever members to release the dogs  1321  from the shoulders  1352 . Rather, legs  1318  are flexible so that, upon application of sufficient pulling force on aperture member  1314 , the legs themselves will flex outwardly such that the aperture member  1314  can be pulled out (after the threader member  1316  has been withdrawn) by simply pulling with enough force to spread legs  1318  apart so that the dogs  1351  on the aperture member  1314  clear the shoulders  1353  on the handle  1312 . The minimum amount of force necessary for that to occur should be greater than the maximum amount of force necessary to withdraw the threader member  1316  through the tubes  1320  of the aperture member  1314  in order to avoid the possibility of inadvertently pulling out the aperture member  1314  along with the threader member  1316  when the threader member is withdrawn. 
       FIG. 70A  is a cross sectional view similar to that of  FIG. 69F  illustrating yet another embodiment of an aperture member  1314   b . In this embodiment, there are no lever members  1325  that must be squeezed together or legs  1318 . Rather, each tube  1320   a  of the aperture member  1314   a  is formed with a small hole  1360  radially opposite a small tab  1362 . The hole  1360  and tab  1362  may be laser cut, for instance. In the cross sectional view, only half of the each hole  1360  and half of each tab  1360  is shown, but it should be clear that the holes  1360  are circular holes and the tabs  1362  are formed by making a U-shaped cut in the tube  1320   a  directly radially opposite the hole  1360 . During assembly, the aperture member  1314   b  is slid laterally into the handle  1312   a  to the position shown in  FIG. 70A . Then a small pin (not shown) is inserted into each tube  1320   a  through the small hole  1360  and used to bend the tab  1362  outwardly from the tube  1320   a  so that it extends into the cavity  1364  in the handle  1312   a  as shown in  FIG. 70B . At this point, the aperture member  1314   a  cannot be pulled out from the handle  1312   a  unless the tab  1362  is bent back inwardly because the tab will hit up against the edge of the cavity  1364 . Accordingly, this is another mechanism for holding the aperture member  1314   a  to the handle  1312   a  unless and until the aperture member  1314   a  is pulled laterally away from the handle  1312   a  with enough force to cause the tabs  1362  to bend back inwardly and become clear of the edges of the cavities  1364 . 
     Again, the minimum pulling force required for this to happen should be set to a force greater than the maximum force required to pull the threader member (not shown) free of the aperture member  1314   a  so that, when the surgeon first pulls the threader member out to thread the sutures through the tubes  1320   b  of the aperture member  1314   a , he or she does not inadvertently also pull out the aperture member  1314   a  from the handle  1312   a.    
     Note that, in the embodiments of  FIGS. 69A-069H  and  70 A- 70 B, the tubes  1320  that hold the slits  1333  of the suture shuttle open  1323  are oriented orthogonal to the tubes in the embodiments of  FIGS. 56A through 61C . Accordingly, the ribbon of the suture shuttle does not need to twist in order to be mounted on the tubes. Rather, the ribbon of the suture shuttle can remain perfectly flat over its entire length up until the slits are spread apart for mounting over the tubes. These embodiments therefore also reduce the possibility of kinking, binding, or unduly stressing the ribbon of the suture shuttle. 
     Tenth Set of Exemplary Embodiments 
     In surgery, it is possible that the surgeon may find that the sutures have been locked in the eyelet with less tension on the tissue than desired. For example, it is often the case in a double-row repair such as described above in connection with  FIGS. 34 and 35 , that the surgeon locks the sutures in a first anchor and then subsequently locks the sutures in a second anchor with more tension than the sutures were locked in the first anchor, causing the sutures locked in the first anchor to become less tensioned. 
     The tension on the sutures may be increased by screwing the anchor further down into the bone, such as by using the tool described hereinbelow in connection with  FIGS. 64A and 64B . However, other mechanisms also may be provided for enhancing the ability to tension after implantation. 
       FIG. 62  illustrates an embodiment of the bone anchor with a ratchet and pawl mechanism between the eyelet pin and the anchor main body that provides a mechanism by which sutures already locked in the eyelet of the eyelet pin may be tightened even further. Particularly,  FIG. 62  is a top plan view of a bone anchor that will permit the surgeon to twist the eyelet pin around its longitudinal axis after the eyelet pin has been pushed down into the closed position locking the sutures in the eyelet. The twisting will wrap the sutures around the eyelet pin in order to take up slack or increase tension on the sutures. 
     The bone anchor  970  illustrated in  FIG. 62  is essentially identical to the bone anchor described above in connection with  FIGS. 52 to 56C , except for the addition of the ratchet and pawl system as described below. However, this is merely exemplary insofar as this concept of a locking, rotatable eyelet pin can be applied to any of the anchors described in this specification and, in fact, to other anchors. Particularly, a series of ratchet cogs  977  may be disposed on the outer radial wall of the eyelet pin  978  of the bone anchor main body  971 . Further, a pawl in the form of pin  973  may be included in the radial wall  972  of the internal bore of the anchor main body  971 . The mechanism will allow the eyelet pin  978  to be rotated in one direction and prevent it from rotating in the opposite direction. The ratchet pawl may rely on the inherent resilience of their specific design and/or material from which they are made to permit the cogs  977  to clear the pin  973  (in one direction). Alternately, the pin may be spring loaded to allow the pawl to clear the ratchet cogs (in one direction). 
     With such a mechanism, the proximal bore  975  of the eyelet pin  978  may be contoured to mate with the head of a torquing tool that may be inserted into the proximal bore  975  of the eyelet pin  978  in order to turn it so as to wrap the sutures around the eyelet pin to increase the tension on the sutures. As mentioned above, this may be done with the eyelet pin  1104  in the closed position. However, it also may be performed with the eyelet pin still in the open position to set the desired tension before locking. For instance, with the surgeon manually holding tension on the sutures, he or she may twist the eyelet pin  978  in order to wrap the sutures around the eyelet pin and increase the tension on the sutures, and then, subsequently, drive the eyelet pin into the closed position, locking the sutures in the eyelet. 
       FIG. 63  illustrates (in perspective cross-section) yet another possible embodiment providing a means by which suture tension may be increased after locking. This embodiment provides a mechanism by which the eyelet pin  983  can be driven further down into the anchor body  981  even after the eyelet pin has been deployed into the closed position. For instance, as illustrated in  FIG. 63 , the second ramp  407  on the body of the eyelet pin of  FIGS. 36-41  may instead be replaced with a vertically oriented ratchet  982  (essentially a plurality of mini ramps) Particularly, as discussed above in connection with the embodiment of  FIGS. 36-41 , the first ramp  983  ( 406  in the embodiment of  FIGS. 36-41 ) acts in conjunction with the C ring  984  ( 404  in the embodiment of  FIGS. 36-41 ) to keep the eyelet pin from falling out of the anchor body when in the open position. In the embodiment of  FIGS. 36-41 , the second ramp  407  acts in conjunction with the C ring to hold the eyelet pin in the closed position after deployment. 
     In this embodiment, the ratchet  982  essentially is a plurality of mini ramps to permit the eyelet pin to be driven into a plurality of different closed positions, each one successively deeper in the anchor main body  981 . Thus, the surgeon can lock the sutures in the eyelet by driving the eyelet pin  983  down so that only the lowest mini ramp ratchets past the C ring  984 . Then, if it is later desired to increase the tension on the suture locked in the eyelet, the surgeon can return to the anchor and drive the eyelet pin further down over the central pin. Any reasonable impactor-type tool, such as the impactor tool described hereinabove in connection with  FIGS. 46-48 , may be used to drive the eyelet pin further down as described so that further ones of the mini ramps pass the C ring. 
     Exemplary Embodiment of a Redeployment/Adjustment Tool 
     As previously mentioned, the bone anchor of the present invention is adjustable or redeployable after implantation, if necessary.  FIG. 64A  is a perspective view of an exemplary redeployment/adjustment tool  1000  for such purposes and  FIG. 64B  is a cross-sectional side view of the distal end of the tool. This tool  1000  is particularly adapted to work with the bone anchor  581  illustrated in  FIGS. 56A-56C . However, other designs adapted to work with the same or different anchors are possible. This particular exemplary tool comprises a removable handle  1001 , a shaft  1002  extending from the handle  1001 , and a shaped head  1003  at the distal end of the shaft. 
     The handle  1001 , shaft  1002 , and associated head  1003  can be used to adjust or remove an implanted bone anchor. Particularly, if a bone anchor needs to be adjusted or removed after implantation, the tool  1000  may be inserted to engage the bone anchor  581  with the head  1003  of the tool. More particularly, the head  1003  of the tool  1000  may be shaped essentially identical to the shaped head  563   c  of the shaft  563  of the implantation tool  561  described above in connection with  FIGS. 54A-56C . That is, it has a head shaped to match the pattern  584  of the proximal end of the internal bore  560  of the main body  580  of the anchor  581 . Preferably, the head  1003  is shaped and sized to form a friction fit between the wall of the inner-bore  560  of the bone anchor main body  580  and the outer radial wall of the eyelet pin  521  and/or friction ring  552 . If the eyelet pin has an overhang such as the overhang  524  of the eyelet pin  521  of the embodiment of  FIG. 56A , the tool head  1003  would need to accommodate such overhang. The friction fit should be strong enough to permit the bone anchor to be lifted out of the bone after it has been unscrewed from bone (in the case of redeployment), yet weak enough that, if the bone screw  581  remains implanted in the bone, pulling up on the tool  1000  will cause the head  1003  to slip out of the interference fit without causing the bone screw to tear out of the bone or otherwise disturb the bone in which it is implanted. Hence, using the redeployment/adjustment tool  1000 , the surgeon can (1) screw the bone screw further into bone, (2) screw it partially out of the bone, or (3) screw it entirely out of the bone and redeploy it in another location or remove it from the patient&#39;s body, as needed. 
     Since, as previously described, the central pin and eyelet pin combination is freely rotatable within the anchor body, the anchor may be further screwed into the bone even after sutures are positioned in the eyelet without problem. While the suture may become wrapped around the adjustment tool during screwing, once the adjustment tool is removed, the central pin and eyelet pin combination will simply rotate within the anchor body back to a rotational orientation in which the eyelet passage aligns with the direction from which the sutures emanate. 
     The tool  1000  also may be designed to serve double duty as the tool for turning the eyelet pin in the above-described embodiment of  FIG. 62 . For instance, a bore  1004  may be provided through the handle  1001 , shaft  1002 , and head  1003  of the tool with a rod  1005  disposed in the bore  1004  that is rotatable and translatable therein. This internal rod  1005  bears a second head  1006  shaped to engage the proximal bore  975  in the eyelet pin  978  of  FIG. 62  (which has a mating pattern to allow the eyelet pin to be twisted by turning the rod  1005  of the tool  1000 ). There is any number of designs that would allow a surgeon to manipulate rod  1005  inside of bore  1004  from the proximal end of the tool  1000 .  FIGS. 64A and 64B  illustrate one such embodiment. In this embodiment, internal rod  1005  runs completely through rod  1002  and first handle  1001  and extends from the proximal end of tool  1000  so that a second handle  1007  can be placed on the proximal end of rod  1005 . The second handle  1007  is engagable with the proximal end of rod  1005  so that the second handle  1007  can be manipulated to both (1) advance the internal rod  1005  distally relative to external shaft  1002  (and head  1003 ) so that it can engage the proximal bore  975  of the eyelet pin  978  (without also causing the external head  1003  to engage the pattern  584  in the proximal end of the internal bore  560  of the main body  580  of the anchor  581 ) and (2) twist the internal rod  1005  and its head  1006  independently of the shaft  1002  and its head  1003  to allow the surgeon to rotate the eyelet pin  978  to cause the suture to wrap around it as previously described. 
     When the tool  1000  is used in situations where it is not necessary, possible, or desired to wrap the sutures around the eyelet pin, the entire inner structure (rod  1005 , head  1006 , and handle  1008 ) can be omitted from the tool structure (or at least removed from the tool prior to use). 
     On the other hand, a head such as head  1006  for engaging a proximal bore in the eyelet pin may be useful even during redeployment, namely, as a guide for guiding the primary tool head  1003  into engagement with the anchor during redeployment/adjustment. Thus, the head  1006  may be spring-loaded on the rod  1005  to help in guiding the primary head into the anchor body. Alternately, in embodiments of the tool  1000  not adapted to twist the eyelet pin, a spring-loaded tip may be provided extending from the end of the shaft  1002  inside of and through head  1003 . 
     Eleventh Set of Exemplary Embodiments 
       FIG. 65  illustrates another alternative embodiment of the present invention. In this embodiment, the entire implant comprises merely a central pin  901  and an eyelet pin  903 . There is no separate anchor body or related accoutrements (such as the C-ring or retaining ring). The central pin and eyelet pin similar to the central pin and eyelet pin of the embodiment of  FIGS. 52A-56C , but this is merely exemplary. Specific implementations in accordance with this embodiment of the invention also may be made using the central pin and eyelet pin of  FIGS. 36-41  (or other configurations). 
     In any event, in this embodiment, the distal end  901   b  of the central pin  901  itself bears threads  905 . Therefore eliminating any need for a separate anchor main body for purposes of attaching the anchor  900  to bone. The outer periphery of the shelf  902  in the central pin  901  may bear formations  904  to mate with a torquing tool having mating internal formations so that the anchor  900  may be screwed into bone. In fact, a tool for implanting this particular device may be quite similar to the tool  561  discussed above in connection with the embodiments of  FIGS. 52A-57K . Particularly, in one embodiment, the tool may be frangibly connected to the shelf  902  of the central pin  901  much in the same way that the tool  561  was frangibly attached to the retaining ring  541  in the embodiments of  FIGS. 52A-57K  so that the tool and central pin  901  can be rotated about their longitudinal axes to screw the anchor  900  into bone without loading the frangible portions. Also similarly, the eyelet pin  903  can be driven down over the central pin  901  until the distal end  903   b  of the eyelet pin hits the top surface  902   a  of the shelf  902  using essentially the same structure for achieving this as is found in the tool  561  of the embodiments of  FIGS. 52A-57K . Specifically, just as in that embodiment, as the rod in the tool pushes against the top  903   b  of the eyelet pin  903 , the eyelet pin  903  is forced down over the central pin  901  until it hits the shelf  902 . Thereafter, continued pushing of the rod will force the hollow shaft of the tool upward relative to the rod and eyelet pin  903 , thereby breaking the frangible portions and releasing the tool from the anchor  900 . 
     Not only may the central pin and eyelet pin concept of the present invention be used (1) with anchor main bodies, as described in connection with  FIGS. 36-57K  or (2) independently of any separate anchor body, as described hereinabove connection with  FIG. 65 , but it also may be incorporated into many other implants or bodies. 
     Furthermore, the anchors described hereinabove have been discussed primarily in connection with use in connection tissue to bone by attaching sutures to the tissue and then attaching those sutures to the anchors. However, in other applications, the anchors may be used to attach any elongate member, including elongate tissue, directly to bone by passing the tissue itself directly through the eyelets. Ligaments and tendons, for instance, can be passed directly through the eyelet of one of the aforedescribed bone anchors instead of a suture attached to the ligament or tendon. 
     Twelfth Set of Exemplary Embodiments 
       FIGS. 66A-66C  show an alternative embodiment of an implantation tool  1200 , and particularly the suture cleat and thumb rest features thereof.  FIG. 66A  is an assembled perspective view,  FIG. 66B  is an exploded perspective view, and  FIG. 66C  is a cross-sectional side view of the implantation tool. 
     The thumb rest and suture cleat features, as will be described in detail herein below, may be incorporated into any of the previously described implantation tools. In fact, these features may be incorporated into other implantation tools. 
     In the illustrated embodiment, the handle  1202  of the tool  1200  includes a lateral through opening, in this embodiment, a slot  1204 , through which a lateral member  1206  extends for supporting combination thumb-rest and suture-cleat bodies  1208  on the handle. Both thumb rests and suture cleats have been discussed hereinabove (see, for example,  FIGS. 54A ,  55 B,  57 A, and  61 C and the related discussions) and their functions in the present embodiment are essentially the same as in those earlier-described embodiments. The lateral member  1206  extends completely through the lateral slot  1204  and extends from both sides of the handle  1202 . Two bodies  1208  are attached to the opposing longitudinal ends  1206   a ,  1206   b  of the lateral member  1206  by any reasonable means, such as by adhesive, a compression fit inside of slots, a rivet, a flared stern. In the illustrated embodiment, the thumb-rests/suture-cleat bodies  1208  are held to the lateral member  1206  by screws  1209  (with washers  1211 ) that pass through holes  1213  in bodies  1208  and into threaded bores  1215  in the lateral member  1206 . 
     The lateral member  1206  is not affixed in the slot, and the thumb-rest/suture-cleat bodies  1208  are spaced a distance, d, from each other on the lateral member  1206  that is slightly longer than the width of the handle  1202  at the slot  1204  such that the assembly of the bodies  1208  and lateral member  1206  can slide a short distance within the slot  1204  in the longitudinal direction of the lateral member  1206 , for example, about 2 mm. The distance that the lateral member  1206  can slide in slot  1204  may be selected depending on the thickness of the sutures that are intended to be locked in the cleat, as will be discussed in more detail below. Additionally, the cross-section of the lateral member  1206  may be made slightly smaller than the cross-section of the slot  1204  so that the lateral member  1206  is monoaxial or polyaxial over a small angular range, i.e., it can roll, pitch, and/or yaw slightly, e.g., about 8°. 
     The radially inner surface  1214  of the thumb-rest/suture-cleat bodies  1208  may be contoured in such a manner so that the space  1216  between the bodies  1208  and the handle  1202  (best seen in the cross-sectional view of  FIG. 66C ) is tapered, thereby allowing sutures to be easily cleated or wedged between the handle  1202  and the surface  1214 . More particularly, the radially inner surfaces  1214  of the thumb-rest/suture-cleat bodies  1208  are convex, with an apex adjacent the lateral member  1206 . One set of exemplary dimensions are shown in  FIG. 66C . Specifically, approximately the radially inner half (i.e., radially toward the lateral member  1206 ) of the surface  1214  is flat and the radially outer half is sloped away from the handle at about 5°. Alternately or additionally, the handle body  1202  can be convex. Preferably, the surface  1214  is smoothly contoured so that it cannot cut or nick cleated sutures. Alternately, the entire surface  1214  may be sloped. In yet other embodiments, the entire surface  1214  may be flat as long as the width, w 1 , of the space between two surfaces  1214  of the bodies  1208  as mounted on the lateral member  1206  is greater than the width, w 2 , of the handle  1202  at the slot  1204  by an amount less than the diameter of a suture so that a suture must be compressed in order to fit in space  1216 . 
     As previously noted, after the surgeon has run the suture(s) through the tissue that is to be reattached to the bone and through the open eyelet in the bone anchor that is attached to the bone, the surgeon pulls on the suture(s) to apply the desired amount of tension to pull the tissue against the bone. The surgeon may rest his or her thumbs on the thumb rest bodies for leverage while holding the suture(s) in other fingers. Also as previously mentioned, in many cases, the surgeon may wish to temporarily cleat the sutures to the handle under this tension before the eyelet pin is deployed into the closed position (thereby locking the suture(s) in the eyelet pin under tension) in order to free his hands for other tasks. 
     Thus, the surgeon can, if desired, use the thumb rests to pull tension on the sutures and then wrap the suture around the lateral member within the space  1216  between the bodies  1208  and the handle  1202 . The dimensions of the lateral member  1206  and the thumb-rest/suture-cleat bodies  1208  as well as the convex shape of the surface  1214  of the bodies are all selected relative to each other and the handle  1202  so as to fixedly wedge one or two sutures between the surface  1214  of the body  1208  and the handle  1202 , but also allow the suture(s) to be readily released form the wedge by unwrapping. 
     The surgeon can wrap one or more sutures around the lateral member  1206  in this space  1216 , the wrapping motion with tension causing the suture(s) to become lodged tightly between the surface  1216  of the body  1208  and the outer surface of the handle body  1202 . Since, in this embodiment, the suture is wedged essentially behind the body  1208 , the surgeon often may be able to at least partially wrap the suture around the lateral member  1206  while still resting his or her thumbs against the thumb rests, thus facilitating the surgeon&#39;s ability to maintain the desired tension on the suture when wrapping. The surgeon generally will want to wrap the suture(s) at least one full revolution around the lateral member  1206 . 
     Generally, when using the implantation tool to implant a bone anchor and reattach tissue to bone, there will be one or two suture strands at any given time that the surgeon may wish to hold under tension using this feature. Accordingly, the dimensions of the pieces can be selected so as to optimize the gripping power of the design for one or two sutures. Also, depending on the procedure, the surgeon may wish to wrap two sutures around the lateral member on one side of the handle or one suture on each side of the handle. 
     The manner in which the sutures are squeezed or gripped so as to be held under tension between the thumb-rest/suture-cleat body  1208  and the handle  1202  is the result of one or more of several factors depending on the specific design and dimensions. First, at least the portion of the space  1216  closer in to the center preferably is less wide than the diameter or thickness of the sutures that will be cleated within the space  1214 . The sutures are resilient and compressible and therefore will themselves be compressed and become wedged in the space  1216  as they are forced into the space  1214 , thereby providing the expansive force to cause them to be gripped between the body  1208  and the handle  1202 . 
     The invention is particularly useful when used with high strength UHMW polyethylene sutures. Polyethylene sutures have become the premium standard for orthopaedic soft tissue (tendon and ligaments) repair. The cross-section of a typical polyethylene suture will reshape from round to flat under tension and may compress up to 75% of its original diameter. However, polyethylene sutures are elusive and difficult to hold; hence making the present cleating feature particularly useful in connection with such sutures. 
     Also, if the lateral member  1206  is slightly smaller than the slot  1204  so that the lateral member  1206  is polyaxial (or even monoaxial) over a small angular range within slot  1204 , this may help the suture become wedged and/or unwedged from the space. Additionally, the handle and/or thumb rests can be made of a tacky and/or resilient material such that the tackiness and/or resilience helps grab the suture(s). Finally, the thumb-rest/suture-cleat bodies  1208  may include a cam feature (not illustrated) or screw feature (also not illustrated) to assist in quickly locking or unlocking retained sutures. For instance, the thumb-rest/suture-cleat bodies  1208  may be mounted to the lateral member  1206  such that they are translatable along the longitudinal axis of the lateral member  1206 , and a cam mechanism may be disposed on the outer end of the body  1208  that can be rotated to force the body  1208  in toward the handle to reduce the width of the gap  1216  to lock a suture therein. 
     CONCLUSION 
     As mentioned earlier, the exact configurations of the bone anchor devices are greatly variable, particularly within the parameters hereinabove described. Individual devices thus can be associated with particular predetermined features that will render them most effective for performing specific procedures. Also it should be noted that many of the features described in connection with individual embodiments of the present invention may be substituted into one or more of the other embodiments described herein, there being no limitation other than logic and physical limitations as to how the various features can be mixed and matched in a single device. The same is true for the surgical procedures disclosed herein, i.e., certain aspects of certain of the described surgical procedure embodiments may be used in other described surgical procedure embodiments described herein and/or may be performed in connection with other embodiments of the bone anchor devices and/or time fastener devices than those used in the exemplary embodiments described herein. 
     The procedures and medical devices as described can be altered in various further ways while still accomplishing the same results and the invention also covers such variations in the procedure. 
     It is submitted that, with the use of the present invention, the arthroscopic rotator cuff repair procedure is significantly facilitated by the use of the bone anchor device and/or the tissue fastener device of the present invention. 
     It must be understood in the above regard that one of the biggest challenges in arthroscopic surgery is knot tying. It is technically challenging and, insofar as the use of the bone anchor devices and/or the tissue fastening devices of the invention facilitate knotless suture fixation, the challenges associated with knot tying are largely overcome. 
     It must also be understood in the above regard that another challenge in arthroscopic surgery is suture management. It is technically challenging and, insofar as the use of the medical device of the invention facilitates effective suture management and loading of the suture anchor, the challenges associated with suture management are largely overcome. 
     Although other knotless fixation devices are already known, some of these require an anchor body to which a suture must be anchored to be located in a pilot hole. It is technically challenging to place an anchor body into the pilot hole, particularly because the hole often bleeds, obscuring the hole and, even if the hole does not bleed, recreating the exact angle that was used during the creation of the pilot hole is sometimes difficult. Placement of cannulas directly over a pilot hole also may create a suction effect dragging soft tissue over the hole, further obscuring it. It is thus often time-consuming and frustrating to locate the hole and correctly locate the bone anchor device in the hole. Incorrect angular location of an anchor device in a hole may occur from the precise angle of insertion necessary for good bone purchase and this may result in failure of some of the known knotless fixation devices. The procedures associated with the self drilling and self tapping bone anchor devices of the present invention as above described alleviate the problem of finding a pilot hole for a bone anchor device. Insofar as the use of other known knotless fixation devices and generally anchor devices may be associated also with various other problems and difficulties, either generally or specifically in relation to specific devices, the use of the medical device of the invention may serve also to at least alleviate these problems and difficulties. 
     It is also known that all presently available anchor designs are “buried” below the bone. This is done to prevent impingement of the head of the device with surrounding anatomy. Although the medical device of the invention may use a body with either no head or a lower profile head that allows the body to be buried below the bone, there are distinct advantages to using an anchor main body having a head that remains accessible externally of the humerus. As such, the anchor main body can be easily unscrewed from the humerus. With respect to some embodiments described herein, it is also possible to pull the eyelet pin from its anchor main body. The above may be necessary where a repair has failed and/or is not satisfactory and needs to be removed, where inadvertent suture dislodgement from the anchor device has occurred where irreversible tanglement of sutures has occurred, and/or where a suture knot comes loose. It is envisaged in this regard that bone anchor devices in accordance with the invention may be provided with anchor main bodies of larger diameter for placement in original holes formed by removed anchor main bodies to provide for optimal purchase strength of the device to bone. The use of the bone anchor device of the invention, therefore, reduces or eliminates the need, in the circumstances described above, for placing additional anchors within the limited space available for a repair, additional bone anchors may induce the risks of confluence of anchor holes, bone fracture and/or anchor pull-out. It must also be understood in relation to the use of known anchor devices, that at times the devices can be removed only by coring techniques that are cumbersome and time consuming and that often lead to significant bone loss that requires bone grafting. Bone grafting in itself may be associated with problems, thus rendering the use of the medical device of the invention significantly more appropriate in relation to many different procedures, when compared with the use of known anchoring techniques and anchoring devices, even known knotless fixation devices. 
     It is thus submitted that the known problems associated with the tying of sutures, the management of sutures and also the anchoring of sutures to the humerus, are largely alleviated, the same applying also in relation to other procedures with which the medical device of the invention can be conveniently used, either arthroscopically, or otherwise. 
     Having thus described a few particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements as are made obvious by this disclosure are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto.