Abstract:
A surgical tool includes a shaft for receiving implants. The shaft defines a non-linear track. The tool includes a deployment member movable along the track to deploy the implants. An implant includes a body, and a plurality of alternating threads and flutes helically arranged about the body such that the body rotates under a linear applied force. Alternatively, an implant includes a body having a distal end for pound-in advancement into tissue. The body includes a plurality of cone-shaped, stacked barbs. A surgical tool includes two implants. The first implant has forward threads and the second implant has reverse threads. The first implant has threads for rotary advancement into tissue and the second implant is configured for pound-in advancement into tissue. The first and second implants are configured for pound-in advancement into tissue.

Description:
BACKGROUND  
         [0001]    Soft tissue such as ligaments and tendons, after they have torn away from bone, can be reattached using suture. A surgeon inserts an anchor with an attached suture into the bone and ties the suture about the soft tissue to secure the soft tissue to the bone. It is known to use pound-in and screw-in type anchors. Tools for inserting pound-in type anchors generally include an outer tube in which the anchor is located, and an inner pusher tube for expelling the anchor from the tool. Tools for inserting screw-in type anchors generally have a tube that is somehow keyed to the anchor, typically by including a hexagonal-shaped end on the anchor and a hexagonal-shaped opening in the tube for receiving the end of the anchor, such that rotation of the tool acts to screw in the anchor.  
         SUMMARY  
         [0002]    According to one aspect of the invention, a surgical tool includes a shaft for receiving implants. The shaft defines a non-linear track. The tool includes a deployment member movable along the track to deploy the implants.  
           [0003]    Embodiments of this aspect of the invention may include one or more of the following features.  
           [0004]    The track includes longitudinal and lateral sections. The deployment member includes a nub received in the track. The deployment member includes a handle and the nub extends from an inner surface of the handle. The deployment member includes a pusher for engaging the implants. The shaft defines a lumen for receiving the pusher.  
           [0005]    The track defines a formation for releasably locking the deployment member. The formation is a concavity, and the deployment member includes a nub releasably received in the concavity.  
           [0006]    The shaft is a cylindrical member and defines a lumen for receiving the implants.  
           [0007]    The shaft includes an adapter defining the track and a longitudinally extending member for receiving the implants. The surgical tool includes a second shaft coupled to the adapter and positioned alongside the longitudinally extending member. The surgical tool includes a hole forming member received by the second shaft and a lever coupled to the hole forming member for distally advancing the hole forming member relative to the second shaft. The adapter defines a second track for receiving the lever. Alternatively, a nub is received in the first track for advancing the hole forming member relative to the second shaft.  
           [0008]    According to another aspect of the invention, a surgical tool includes implants and a shaft for receiving the implants. The shaft defines a non-linear track. The surgical tool includes a deployment member movable along the track to selectively deploy the implants.  
           [0009]    Embodiments of this aspect of the invention may include a spacer disposed between two implants.  
           [0010]    According to another aspect of the invention, a method includes advancing a shaft to a surgical site, the shaft housing implants, and moving a deployment member along a non-linear track defined by the shaft to deploy the implants into tissue at the surgical site.  
           [0011]    According to another aspect of the invention, an implant includes a body, and a plurality of alternating threads and flutes helically arranged about the body such that the body rotates under a linear applied force. Each thread includes multiple barbs.  
           [0012]    Embodiments of this aspect of the invention may include that the body defines a longitudinal passage.  
           [0013]    According to another aspect of the invention, an implant includes a body having a distal end for pound-in advancement into tissue. The body includes a plurality of cone-shaped, stacked barbs, and a diameter of an outermost region of the barbs increases proximally.  
           [0014]    Embodiments of this aspect of the invention may include a proximal break-away hub.  
           [0015]    According to another aspect of the invention, a surgical tool includes a first member, a first implant coupled to the first member, a second member coupled to the first member, and a second implant coupled to the second member. The first implant has forward threads and the second implant has reverse threads.  
           [0016]    Embodiments of this aspect of the invention may include one or more of the following features.  
           [0017]    The surgical tool includes a suture joining the first and second implants. The first member defines a lumen and the second member is received within the lumen. The surgical tool includes a deployment element for advancing the second member relative to the first member.  
           [0018]    According to another aspect of the invention, a surgical tool includes a first member, a first implant coupled to the first member, a second member coupled to the first member, and a second implant coupled to the second member. The first implant has threads for rotary advancement into tissue and the second implant is configured for pound-in advancement into tissue.  
           [0019]    Embodiments of this aspect of the invention may include one or more of the following features.  
           [0020]    The surgical tool includes a suture joining the first and second implants. The first member defines a lumen and the second member is received within the lumen. The surgical tool includes a deployment element for advancing the second member relative to the first member.  
           [0021]    According to another aspect of the invention, a surgical tool includes a first member, a first implant coupled to the first member, a second member coupled to the first member, and a second implant coupled to the second member. The first and second implants are configured for pound-in advancement into tissue.  
           [0022]    Embodiments of this aspect of the invention may include one or more of the following features.  
           [0023]    The surgical tool includes a suture joining the first and second implants. The first member defines a lumen and the second member is received within the lumen. The surgical tool includes a deployment element for advancing the second member relative to the first member.  
           [0024]    The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
       
    
    
     DESCRIPTION OF DRAWINGS  
       [0025]    [0025]FIG. 1 is a perspective view of a suture anchor insertion tool;  
         [0026]    [0026]FIG. 2A is a perspective view of a handle of the suture anchor insertion tool of FIG. 1;  
         [0027]    [0027]FIG. 2B is a perspective view of an adaptor of the suture anchor insertion tool of FIG. 1;  
         [0028]    [0028]FIG. 2C is a perspective view of a member of the suture anchor insertion tool of FIG. 1;  
         [0029]    [0029]FIG. 3 is a hidden line view of a distal portion of the suture anchor insertion tool of FIG. 1;  
         [0030]    [0030]FIG. 4 is a perspective view of a suture anchor assembly;  
         [0031]    FIGS.  5 A- 5 C are diagrammatic illustrations of the insertion tool of FIG. 1 shown at various stages during deployment of suture anchors;  
         [0032]    [0032]FIG. 6A is a perspective view of an alternative embodiment of a suture anchor insertion tool;  
         [0033]    [0033]FIG. 6B is a perspective view of an adaptor of the insertion tool of FIG. 6A;  
         [0034]    [0034]FIG. 6C is another perspective view of the adaptor of the insertion tool of FIG. 6A;  
         [0035]    [0035]FIG. 7 is a hidden line view of a distal portion of the suture anchor insertion tool of FIG. 6A;  
         [0036]    [0036]FIG. 8A- 8 CF are diagrammatic illustrations of the insertion tool of FIG. 6A shown at various stages during deployment of suture anchors;  
         [0037]    [0037]FIG. 9A is a perspective view of another alternative embodiment of a suture anchor insertion tool;  
         [0038]    [0038]FIG. 9B is a perspective view of an adaptor of the insertion tool of FIG. 8A;  
         [0039]    [0039]FIG. 9C is another perspective view of the adaptor of the insertion tool of FIG. 8A;  
         [0040]    [0040]FIG. 9D is a perspective view of a member of the suture anchor insertion tool of FIG. 9A;  
         [0041]    [0041]FIG. 9E is a perspective view of a handle of the suture anchor insertion tool of FIG. 9A;  
         [0042]    [0042]FIG. 10A- 10 E are diagrammatic illustrations of the insertion tool of FIG. 8A shown at various stages during deployment of suture anchors;  
         [0043]    [0043]FIG. 11 is a perspective view of another alternative embodiment of a suture anchor insertion tool;  
         [0044]    [0044]FIG. 12 is a perspective view of another alternative embodiment of a suture anchor insertion tool;  
         [0045]    [0045]FIG. 13A is a cross-sectional view taken along lines  13 A- 13 A of FIG. 12;  
         [0046]    [0046]FIG. 13B is a cross-sectional view taken along lines  13 B- 13 B of FIG. 12;  
         [0047]    [0047]FIG. 14A is a perspective view of a suture anchor;  
         [0048]    [0048]FIG. 14B is an end on view of the suture anchor of FIG. 14A;  
         [0049]    [0049]FIG. 14C is a cross-sectional view taken along lines  14 C- 14 C of the suture anchor of FIG. 14A;  
         [0050]    [0050]FIG. 15A is a perspective view of another suture anchor;  
         [0051]    [0051]FIG. 15B is another perspective view of the suture anchor of FIG. 15A;  
         [0052]    [0052]FIG. 15C is a cross-sectional view taken along lines  15 C- 15 C of the suture anchor of FIG. 15A;  
         [0053]    [0053]FIG. 16A is a perspective view of another suture anchor;  
         [0054]    [0054]FIG. 16B is cross-sectional view taken along lines  16 B- 16 B of the suture anchor of FIG. 16A;  
         [0055]    FIGS.  17 A- 17 F are perspective views of links between suture anchors and sutures;  
         [0056]    [0056]FIG. 18 is another embodiment of an insertion tool with suture anchors;  
         [0057]    [0057]FIG. 19A is a side view of the suture anchors of FIG. 18;  
         [0058]    [0058]FIG. 19B is a top view of the suture anchors of FIG. 18 shown with a suture coupled to the anchors; and  
         [0059]    [0059]FIG. 20 shows the suture anchors of FIG. 18 deployed in tissue. 
     
    
     DETAILED DESCRIPTION  
       [0060]    Referring to FIG. 1, an insertion tool  100  permitting arthroscopic insertion of two anchors coupled by a suture to, e.g., attach soft tissue to bone, includes an outer tubular member  110  for housing the two anchors, an adaptor  130  enabling controlled deployment of the anchors from outer tubular member  110 , and an actuating handle  120  for deploying the anchors. Referring also to FIG. 2A, handle  120  has a nub  126  and adaptor  130  defines a guide track  140  that receives nub  126  such that movement of nub  126  along track  140  guides the deployment of the two anchors from outer tubular member  110 .  
         [0061]    Referring to FIGS. 1 and 2C, outer tubular member  110  has a proximal region  113  and a distal region  111 . Distal region  111  has an anchor receiver  118  for receiving the anchors. Adaptor  130  has a distal face  131  defining a through bore  132  for receiving proximal region  113  of outer tubular member  110 . Outer tubular member  110  has a wall  112  defining a pair of substantially parallel longitudinal slots  114 A,  114 B extending through wall  112  in distal region  111 , for purposes described below.  
         [0062]    Referring to FIGS. 2A and 2B, handle  120  includes a hand grip  120   a  and a plunger member  128 . Hand grip  120   a  has a distal end  121  with a distal wall  124 . Wall  124  defines a circular opening  122  into a conical chamber  123  bounded by an interior wall  125 . Nub  126  extends radially inward from interior wall  125 . Opening  122  and chamber  123  are dimensioned to receive a proximal end  133  of adaptor  130  such that nub  126  is located in track  140  to attain guided relative motion between handle  120  and adaptor  130 . Plunger member  128  is received within adapter through bore  132  and within outer tubular member  110 . Plunger member  128  has a distal region  127  terminating in a contact face  129  for engaging an anchor located within outer tubular member  110 .  
         [0063]    Referring particularly to FIG. 2B, guide track  140  extends from proximal end  133  along part of the length of adaptor  130 . Guide track  140  is formed by a first longitudinal extent  154 , a first lateral extent  150 , a second longitudinal extent  148 , a second lateral extent  144 , and a third longitudinal extent  142 . First longitudinal extent  154  opens at a hole  157  in proximal end  133  to allow nub  126  to enter track  140 . First longitudinal extent  154  extends distally from hole  157  to a first junction  155  with first lateral extent  150 . First lateral extent  150  includes a stop  151  that is dimensioned to releasably receive nub  126  to hinder relative movement of nub  126  along track  140 . Stop  151  is a concave depression in the proximal wall  150 P of lateral extent  150  with a radius of curvature slightly larger than the radius of nub  126 . First lateral extent  150  extends laterally along the outer circumference of adaptor  130  from first junction  155  with first longitudinal extent  154  to a second junction  149  with second longitudinal extent  148 . Second longitudinal extent  148  extends distally from second junction  149  to a third junction  147  with second lateral extent  144 , and has a length of about 1 inch (normalized with respect to a received suture anchor). Second lateral extent  144  includes a stop  145  that is similar to stop  151 , and extends laterally along the outer circumference of adaptor  130  from third junction  147  to a fourth junction  143  with third longitudinal extent  142 . Third longitudinal extent  142  extends distally from fourth junction  143  to an end  141 , and has a length of about 1 inch (normalized with respect to a received suture anchor). The lengths of second longitudinal extent  148  and third longitudinal extent  142  determine the insertion depth of the two anchors housed in member  110 , as discussed further below.  
         [0064]    Referring to FIG. 3, anchor receiver  118  of outer tubular member  110  receives two anchors  80 ,  90 , e.g., pound-in anchors, arranged in a row. Anchors  80 ,  90  each include a distal end  81 ,  91  capped by a tip  82 ,  92  and a proximal end  83 ,  93  with a suture eyelet  84 ,  94  (FIG. 4), respectively. Tips  82 ,  92  are sufficiently robust to penetrate tissue, e.g., bone. Eyelets  84 ,  94  are dimensioned to pass at least one strand of suture for connecting the suture to anchors  80 ,  90 , as discussed below in regard to FIG. 17. Anchors  80 ,  90  are lined by a series of barb threads  85 ,  95  for retaining anchor  80 ,  90  in the penetrated tissue, as discussed below in regard to FIGS.  14 A- 16 .  
         [0065]    Anchors  80 ,  90  are separated by a spacer  60  that is also inside outer tubular member  110 . Spacer  60  has a distal end  61  with a contact face  62  and a proximal end  63  that defines a tip dock  64 . Within tube wall  112 , contact face  62  abuts proximal end  83  of anchor  80 , and tip dock  64  receives tip  92  of anchor  90 . Tip dock  64  is generally conical in shape to increase the contact area with tip  92  and prevent tip  92  from penetrating tip dock  64 . Anchors  80 ,  90  and spacer  60  thus form a mechanical linkage capable of transmitting an expulsion force from anchor  90  to anchor  80  to insert anchor  80  into tissue, e.g., bone.  
         [0066]    Referring also to FIG. 4, an anchor assembly  40  is formed by anchors  80 ,  90  and spacer  60  joined by a suture  50 . Suture  50  is retained in anchor receiver  118  inside outer tubular member  110  along with anchors  80 ,  90  and spacer  60 . Suture  50  has a first knotted loop  51  that passes through eyelet  94  for joining suture  50  to anchor  90 , and a first suture portion  52  that extends from eyelet  94  through eyelet  84 . Suture  50  has a second portion  53  that exits eyelet  84  and is tied in a slip knot  54  with first suture portion  52 . Suture  50  also includes a third suture portion  56  that exits slip knot  54  and extends to an end  57  joined to spacer  60 . With the anchors loaded as shown in FIG. 3, suture runs along either side of anchor  90  with slip knot  54  positioned proximal of anchor  90 . When a surgeon or other operator pulls on spacer  60 , the length of first suture portion  52  is shortened. Slip knot  54  is a one-way knot in that the slip knot permits shortening of suture portion  52 , but limits any tendency of suture portion  52  to lengthen.  
         [0067]    In use, an operator positions insertion tool  100  with anchor receiver  118  oriented toward a selected surgical site  31  in a bone  30 . Surgical site  31  is, e.g., a site where a soft tissue  34  is to be reattached to bone  30 . Insertion tool  100  is preloaded with anchors  80 ,  90 , spacer  60 , and suture  50  with slip knot  54 . Prior to use, nub  126  has been advanced through hole  157  along first longitudinal extent  154  and a portion of first lateral extent  150  of track  140  to stop  151  (FIG. 2B).  
         [0068]    Referring to FIGS. 2B and 5A, the operator then advances anchor receiver  118  to contact surgical site  31  and presses handle  120  distally to release nub  126  from stop  151 . The operator rotates handle  120  in the direction of arrow RI to move nub  126  further along first lateral extent  150  to junction  149 , where nub  126  enters longitudinal extent  148 .  
         [0069]    Referring also to FIG. 5B, the operator then applies an axial force Fl to handle  120 , moving nub  126  distally along second longitudinal extent  148  and advancing plunger member  128  such that contact face  129  of plunger member  128  engages proximal end  93  of anchor  90  pushing anchor  90  distally. Tip  92  of anchor  90  in turn presses against tip dock  64  of spacer  60  which in turn presses against proximal end  83  of anchor  80  to push anchor  80  distally out of tubular member  110 , causing tip  82  of anchor  80  to penetrate into bone  30  at site  31 .  
         [0070]    When nub  126  reaches the end of second longitudinal extent  148  at junction  147 , the penetration of anchor  80  into bone  30  is completed. The operator then rotates handle  120  in the direction of arrow R 2 , moving nub  126  along a portion of second lateral extent  144  of track  140  to stop  145 . The operator then releases the distally-directed pressure on handle  120  so that stop  145  receives nub  126  to hinder further relative movement between handle  120  and adaptor  130 .  
         [0071]    The operator then withdraws-tool  100  from site  31 , drawing suture  50  through slot  114  and spacer  60  and slip knot  54  out of anchor receiver  118 . The operator then aligns anchor receiver  118  with a second surgical site  32 , and presses handle  120  distally to release nub  126  from stop  145 . The operator then rotates handle  120  in the direction of arrow R 2  to move nub  126  further along second lateral extent  144  to junction  143 , where nub  126  enters third longitudinal extent  142 .  
         [0072]    Referring to FIG. 5C, the operator applies a force F2 to handle  120  moving nub  126  distally along third longitudinal extent  142  such that contact face  129  of plunger member  128  pushes against proximal end  93  of anchor  90  pushing anchor tip  92  into bone  30  at site  32 . Penetration proceeds until nub  126  reaches end  141 , at which time anchor assembly  40  is fully deployed from insertion tool  100 . The operator then removes insertion tool  100  from surgical site  32 , pulls on spacer  60  to shorten suture portion  62  and thus hold soft tissue  34  to bone  30 . Slip knot  54  acts to limit loosening of the suture.  
         [0073]    Further embodiments are within the scope of the following claims.  
         [0074]    For example, referring to FIG. 6A, a suture anchor insertion tool  300  permitting arthroscopic insertion of two anchors coupled by a suture to, e.g., attach soft tissue to bone includes an outer tubular member  310  for housing the two anchors, an actuating handle  320  for deploying the anchors, a second tubular member  315  mounted side-to-side with member  310  housing a retractable awl  390  for punching a hole in bone, an actuating lever  337  for controlling awl  390 , and an adaptor  330  enabling controlled deployment of the anchors from member  310  and the awl from member  315 . Referring also to FIGS. 6C and 6D, adaptor  330  defines a first guide track  340  and a second guide track  360 . Guide track  340  guides the deployment of the two anchors from member  310  in the same manner as described above with reference to guide track  140 . Guide track  360  guides the extension and retraction of awl  390  by lever  337 . Lever  337  is coupled to awl  390 , e.g., by a press fit, welding or soldering.  
         [0075]    Outer tubular member  310  has a proximal end  313  and a distal end  311  with an anchor receiver  318  for receiving the suture anchors. Tubular member  310  has a wall  312  with a pair of substantially parallel longitudinal slots  314 A,  314 B extending therethrough at distal end  311 . Referring also to FIG. 7, anchor receiver  318  of member  310  receives anchors  80 ,  90  in the same manner as described above with reference to anchor receiver  118 .  
         [0076]    Member  315  has a wall  316  defining a lumen  316   a  for receiving retractable awl  390 . Member  315  has a proximal end  317  and a distal end  319 . Distal end  317  has an inner radial lip  382  defining a hole  380 . Awl  390  has an extensible portion  394  dimensioned to pass through hole  380 , and a body portion  396 . Extensible portion  394  ends in an awl tip  391 . Body portion  396  is dimensioned to catch on inner radial lip  382  such that body portion  396  cannot extend through hole  380 . Member  315  also includes a compression spring  384  that acts between a distal end  395  of body portion  396  and radial lip  382  to retract extensible portion  394  into lumen  316   a  when lever  337  is moved proximally, as discussed further below.  
         [0077]    Referring to FIGS. 6A and 6B, handle  320  includes a hand grip  320   a  and a plunger member  328 . Hand grip  320   a  has a distal end  321  with a distal wall  324 . Wall  324  defines a circular opening  322  into a conical chamber  323  bounded by an interior wall  325 . Nub  326  extends radially inward from interior wall  325 . Opening  322  and chamber  323  are dimensioned to receive proximal end  333  of adaptor  330  and maintain nub  326  in track  340  to attain guided relative motion between handle  320  and adaptor  330  for deploying two anchors from member  310 . Distal end  321  also defines a longitudinal slit  328   a  that extends proximally from a distal opening  327   a  at wall  324 . Longitudinal slit  328   a  is angularly positioned relative to nub  326  such that, when nub  326  is received in longitudinal extent  342  of adapter  330 , slit  328  is radially aligned with second guide track  360 . Plunger member  328  is dimensioned to slidably fit within member  310 . Plunger member  328  has a distal region  327  terminating in a contact face  329  for engaging an anchor located within outer tubular member  310 .  
         [0078]    Referring to FIGS. 6A, 6C, and  6 D, adaptor  330  has a proximal end  333  and a distal face  331  defining a pair of through bores  332 ,  334 . Plunger member  128  is received within adapter through bore  332 . Proximal end  313  of tubular member  310  is received within through bore  332 , and a proximal end  317  of tubular member  315  is received within through bore  334 . Guide tracks  340 ,  360  extend along opposite sides of adaptor  330 .  
         [0079]    Guide track  340  is formed by a first longitudinal extent  354 , a first lateral extent  350 , a second longitudinal extent  348 , a second lateral extent  344 , and a third longitudinal extent  342 . First longitudinal extent  354  opens at a hole  357  in proximal end  333  to allow nub  326  to enter track  340 . First longitudinal extent  354  extends distally from hole  357  to a first junction  355  with first lateral extent  350 . First lateral extent  350  includes a stop  351  that is dimensioned to releasably receive nub  326  to hinder relative movement of nub  326  along track  340 . Stop  351  is a concave depression in the proximal wall  350 P of lateral extent  350  with a radius of curvature slightly larger than the radius of nub  326 . First lateral extent  350  extends laterally along the outer circumference of adaptor  330  from first junction  355  with first longitudinal extent  354  to a second junction  349  with second longitudinal extent  348 . Second longitudinal extent  348  extends distally from second junction  349  to a third junction  347  with second lateral extent  344 , and has a length of about 1 inch (normalized with respect to a received suture anchor). Second lateral extent  344  includes a stop  345  that is similar to stop  351 , and extends laterally along the outer circumference of adaptor  330  from third junction  347  to a fourth junction  343  with third longitudinal extent  342 . Third longitudinal extent  342  extends distally from fourth junction  343  to an end  341 , and has a length of about 1 inch (normalized with respect to a received suture anchor). The lengths of second longitudinal extent  348  and third longitudinal extent  342  determine the insertion depth of the two anchors housed in member  310 , as discussed further below.  
         [0080]    Guide track  360  is formed by a longitudinal extent  362  and a lateral extent  364 . Longitudinal extent  362  extends distally from a proximal side  361  to a junction  363  with lateral extent  364 . Lateral extent  364  extends laterally along the outer circumference of adaptor  330  from junction  363  to a stop  365 . Stop  365  is dimensioned to releasably receive lever  337  to hinder relative movement of lever  337  along track  360  and maintain extensible portion  394  of awl  390  extended through hole  380 . Stop  363  is a concave depression in the proximal wall  364 P of lateral extent  364  with a radius of curvature slightly larger than the radius of lever  337  in track  360 .  
         [0081]    Referring to FIG. 8A, in use, an operator positions insertion tool  300  with members  310 ,  315  oriented toward a selected surgical site  31  in a bone  30 . Surgical site  31  is, e.g., a site where a soft tissue  34  is to be reattached to bone  30 . Insertion tool  300  is preloaded with anchors  80 ,  90 , spacer  60 , and suture  50  with a slip knot. Nub  326  has been advanced through hole  357  along first longitudinal extent  354  and a portion of first lateral extent  350  of track  340  to stop  351  of FIG. 6C. Awl lever  337  is positioned proximally in track  360  such that the awl is retracted.  
         [0082]    Referring to FIG. 8B, the operator advances lever  337  distally along longitudinal extent  362  of track  360 , advancing the awl out of member  315 . When lever  337  reaches junction  363 , the operator moves lever  337  laterally along lateral portion  364  into stop  365  which receives lever  337  and maintains the awl in the extended position. The operator uses the awl to make a hole  31 H through the soft tissue into bone  30  at surgical site  31 .  
         [0083]    After hole  31 H is formed, the operator moves lever  337  laterally along lateral portion  364  out of stop  365  toward junction  363 . At junction  363 , the operator releases lever  337  and spring  384  (FIG. 7) pushes lever  337  proximally to retract extensible portion  394  of the awl into member  315 .  
         [0084]    Referring to FIG. 8C, the operator then aligns anchor receiver  318  with hole  31 H and presses handle  320  distally to release nub  326  from stop  351 . The operator rotates handle  320  in the direction of arrow R 1  to move nub  326  further along first lateral extent  350  to junction  349 , where nub  326  enters longitudinal extent  348 . The operator applies a force F1 to handle  320 , moving nub  326  distally along second longitudinal extent  348  and advancing contact face  329  of plunger member  328  (shown in FIG. 6B) against proximal end  93  of anchor  90  to deploy anchor  80  as described above. The operator then rotates handle  320  in the direction of arrow R 2 , moving nub  326  along a portion of second lateral extent  344  of track  340  to stop  345  (shown in FIG. 6C). The operator then releases the distally-directed pressure on handle  320  so that stop  345  receives nub  326  to hinder further relative movement between handle  320  and adaptor  330 . Lever  337  has been moved distally in track  360  by the action of handle  320 , though the awl is still fully located within member  315 . referring to FIG. 8D, the operator then withdraws tool  300  from hole  31 H, drawing suture  50  through one of slots  314 A,  314 B and spacer  60  out of anchor receiver  318 . The operator then orients members  310 ,  315  toward a second selected surgical site  32 .  
         [0085]    Referring to FIG. 8E, the operator advances lever  337  distally along longitudinal extent  362  of track  360 , advancing the awl out of member  315 . When lever  337  reaches junction  363 , the operator moves lever  337  laterally along lateral portion  364  into stop  365  which receives lever  337  and maintains the awl in the extended position. The operator uses the awl to make a hole  32 H through the soft tissue into bone  30  at surgical site  32 .  
         [0086]    After hole  32 H is formed, the operator moves lever  337  laterally along lateral portion  364  out of stop  365  toward junction  363 . At junction  363 , the operator releases lever  337  and spring  384  (FIG. 7) pushes lever  337  proximally to retract extensible portion  394  of the awl into member  315 .  
         [0087]    Referring to FIG. 8F, the operator then aligns anchor receiver  318  with hole  32 H and presses handle  320  distally to release nub  326  from stop  345 . The operator rotates handle  320  in the direction of arrow R 3  to move nub  326  further along second lateral extent  344  to junction  343 , where nub  326  enters third longitudinal extent  342 . The operator applies a force F2 to handle  320 , moving nub  326  distally along third longitudinal extent  342  and advancing contact face  329  against proximal end  93  of anchor  90  to deploy anchor  90 , as described above. During the advancement of handle  320 , lever  337  enters track  342  of handle  320 . The operator then moves insertion tool  300  away from hole  32 H, and grasps spacer  60  to tighten suture portion  62  and hold a soft tissue  34  to bone  30 .  
         [0088]    Referring to FIG. 9A, another suture anchor insertion tool  500  permits arthroscopic insertion of two anchors coupled by a suture to, e.g., attach soft tissue to bone. Insertion tool  500  includes an outer tubular member  510  that receives the two anchors and a retractable awl  590 . Awl  590  has a tip  591  for forming a hole in bone. Tool  500  includes an actuating handle  520  for deploying the anchors and extending awl  590 , and an adaptor  530  having a guide track  560  enabling controlled deployment of the anchors and awl  590  from member  510 .  
         [0089]    Referring to FIGS. 9A and 9D, member  510  has a proximal end  513  and a distal end  511  with an anchor receiver  518  for receiving the suture anchors. Member  510  has an outer circumferential wall  512  and an inner wall  516  that divides the interior of member  510  into a plunger channel  515  and an awl channel  517 . Anchor receiver  518  is part of plunger channel  515 . Wall  512  defines a pair of substantially parallel longitudinal slots  514 A,  514 B that extend into anchor receiver  518 . Anchor receiver  518  receives anchors  80 ,  90  as described above. Awl  590  is spring loaded as shown in FIG. 7.  
         [0090]    Referring to FIGS. 9A and 9E, handle  520  includes a hand grip  520   a  and a plunger member  528 . Handle  520  has a distal end  521  bounded by a distal wall  524 . Wall  524  defines a circular opening  522  into a conical chamber  523  bounded by an interior wall  525 . Opening  522  and chamber  523  are dimensioned to receive proximal end  533  of adaptor  530  to attain guided relative motion between handle  520  and adaptor  530 . A pair of nubs  526 ,  527  extend radially inward from interior wall  525 . Nubs  526 ,  527  are relatively positioned to be received by track  560  to enable controlled deployment of the anchors and awl  590  from member  510 . Plunger member  528  is dimensioned to slidably fit within plunger channel  515  of member  510 . Plunger member  528  terminates in a contact face  529 .  
         [0091]    Referring to FIGS. 9A, 9B, and  9 C, adaptor  530  defines a single guide track  560  that guides the deployment of two anchors and extension and retraction of awl  590  from member  510 . Adaptor  530  has a proximal end  533  and a distal face  531  and defines a through bore hole  532  that receives proximal end  513  of tubular member  510  and plunger  528 . Guide tracks  560  wraps around the outer circumference of adaptor  530 .  
         [0092]    Guide track  540  is formed by a first longitudinal extent  582 , a first lateral extent  578 , a second longitudinal extent  576 , a second lateral extent  372 , a third longitudinal extent  568 , a third lateral extent  564 , and a fourth longitudinal extent  562 . First longitudinal extent  582  opens at a hole  583  in proximal end  533  to allow nubs  926 ,  927  to enter track  560 , as discussed further below. First longitudinal extent  354  extends distally from hole  583  to a first junction  581  with first lateral extent  578 . First lateral extent  578  includes a stop  579  that is dimensioned to releasably receive nubs  926 ,  927  to hinder relative movement of nubs  926 ,  927  along track  560 . Stop  579  is a concave depression with a radius of curvature slightly larger than the radius of nub  326 . First lateral extent  578  extends laterally along the outer circumference of adaptor  530  from first junction  581  with first longitudinal extent  582  to a second junction  577  with second longitudinal extent  576 . Second longitudinal extent  576  extends distally from second junction  577  to a third junction  575  with second lateral extent  572 . Second longitudinal extent  576  has a length of about 1 inch (normalized with respect to a received suture anchor). Second lateral extent  572  includes a stop  573  that is similar to stop  579 . Second lateral extent  572  extends laterally along the outer circumference of adaptor  530  from third junction  575  to a fourth junction  569  with third longitudinal extent  568 . Third longitudinal extent  568  extends distally from fourth junction  569  to a fifth junction  567  with third lateral extent  564 . Third longitudinal extent  568  has a length of about 1 inch (normalized with respect to a received suture anchor). Third lateral extent  564  includes a stop  565  that is similar to stop  579 . Third lateral extent  564  extends laterally along the outer circumference of adaptor  530  from fifth junction  567  to a sixth junction  563  with fourth longitudinal extent  562 . Fourth longitudinal extent  562  extends distally from sixth junction  563  to an end  561 , and has a length of about 1 inch (normalized with respect to a received suture anchor).  
         [0093]    Referring to FIG. 10A, in use, an operator positions insertion tool  500  with awl  590  oriented toward a selected surgical site  31  in a bone  30 . Surgical site  31  is, e.g., a site where a soft tissue  34  is to be reattached to bone  30 . Insertion tool  500  is preloaded with anchors  80 ,  90 , spacer  60 , and suture  50  with a slip knot. Nub  526  has been advanced through hole  583  along first longitudinal extent  582  and a portion of first lateral extent  578  of track  560  to stop  579  of FIG. 9B. Nub  526  contacts a proximal end  593  of awl  590  to extend and maintain awl  590  out of awl channel  517 . The operator uses awl  590  to form a hole  311 H in bone  30  and soft tissue  36 .  
         [0094]    Referring to FIG. 10B, after forming hole  31 H, the operator rotates handle  520  in the direction of arrow R 10  to move nub  526  out of stop  579  and into longitudinal extent  576 . This moves nub  526  out of contact with a proximal end  593  of awl  590  to allow a spring (not shown) to retract awl  590  into awl channel  517 , as described above. The operator then positions anchor receiver  518  at hole  31 H in preparation for insertion of anchor  90 .  
         [0095]    Referring to FIG. 10C, the operator applies a force F10 to handle  520  moving nub  526  distally along longitudinal extent  576  and advancing plunger member  528  to deploy anchor  80 . The operator then rotates handle  520  in the direction of arrow R 11 , moving nub  526  along a portion of second lateral extent  572  of track  560  to stop  573  (shown in FIGS. 9B and 9C). The operator then releases the distally-directed pressure on handle  520  so that stop  573  receives nub  526  to hinder further relative movement between handle  520  and adaptor  530 .  
         [0096]    Referring to FIG. 10D, the operator then withdraws tool  500  from hole  311 H, drawing suture  50  through one of slots  514 A,  514 B. The operator then rotates handle  520  in the direction of arrow R 12  to move nub  526  out of stop  573  and to junction  569  of lateral extent  572  and longitudinal extent  568 . The rotation of handle  520  in the direction of arrow R 12  also brings nub  527  into contact with the distal end  593  of awl  590 . The operator then pushes distally on handle  520  to advance nub  526  distally along longitudinal extent  568  and to advance nub  527  into longitudinal extent  582 . The advancement of nub  526  along longitudinal extent  568  pushes spacer  60  out of anchor receiver  518 . The advancement of nub  527  into longitudinal extent  582  extends awl  590  out of awl channel  515 . Once nub  526  reaches junction  567  and nub  527  reaches junction  581 , the operator then rotates handle  520  in the direction of arrow R 13  to move nub  527  into stop  565  in lateral extent  564  and nub  526  into stop  579  in lateral extent  578 . The operator then uses awl  590  to form a hole  32 H in the bone at surgical site  32 .  
         [0097]    Referring to FIG. 10E, after forming hole  32 H, the operator rotates handle  520  in the direction of arrow R 14 . This rotation moves nub  527  out of stop  579  and into longitudinal extent  576 , and moves nub  526  out of stop  565  and into longitudinal extent  562 . This moves nub  526  out of contact with a proximal end  593  of awl  590  to allow the spring to retract awl  590  into awl channel  517 . The operator then positions anchor receiver  518  at hole  31 H in preparation for insertion of anchor  90 . The operator then applies a force F12 to handle  520  moving nub  526  distally along longitudinal extent  562  and nub  527  distally along longitudinal extent  576 , and advancing plunger member  528  to deploy anchor  90 . The operator then moves insertion tool  500  away from hole  32 H, and grasps spacer  60  to tighten suture portion  62  and hold a soft tissue  34  to bone  30 .  
         [0098]    Referring to FIG. 11, another suture anchor insertion tool  800  permits arthroscopic insertion of two anchors coupled by a suture to, e.g., attach soft tissue to bone. Insertion tool  800  includes a handle  810 , an outer tubular member  820  for housing the two anchors, and a plunger member  830  for inserting one of the two anchors, as discussed below.  
         [0099]    Handle  810  has a distal end  811  and a proximal end  813  and defines an interior channel  814  extending therebetween that receives plunger member  830 . Distal end  811  of handle  810  defines a cutout portion  812  for receiving a proximal end  823  of member  820  in, e.g., a compression fit.  
         [0100]    Member  820  has a distal end  821  and proximal end  823 , and has a wall  827  defining an axial channel  824  extending from proximal end  823  to distal end  821 . When proximal end  823  of member  820  is received in cutout portion  812  of handle  810 , axial channel  824  of member  820  communicates with interior channel  814  of handle  810  to form a passage for plunger member  830 . Distal end  821  of member  820  includes a suture anchor receiver  828  for non-rotatably mating with a first suture anchor  880 . Channel  824  is, e.g., hex-shaped in the region of anchor receiver  828 , and anchor  880  includes a mating portion  882  that is, e.g., a male hex head to couple suture anchor  880  to suture anchor receiver  828  for combined rotation. Anchor  880  is held in the channel by, e.g., a friction fit or an interference fit. Suture anchor  880  also includes a thread  884  for facilitating torsional insertion of suture anchor  880  into bone.  
         [0101]    Plunger member  830  includes an elongate rod portion  834  with a distal end  831  defining a contact face  832  and a proximal end  833  terminating in a knob  836 . Rod portion  834  is dimensioned to slide within axial channel  824  of member  820  and axial channel  814  of handle  810 .  
         [0102]    A second suture anchor  890  is received in axial channel  824  of member  820  and is dimensioned to slide therein. Suture anchor  890  is designed for pound-in insertion into bone as discussed in, e.g., FIGS.  14 A- 16 B. Suture anchors  880 ,  890  are, e.g., joined by a suture with a slip knot and separated by a spacer as illustrated in FIG. 4.  
         [0103]    In use, an operator inserts suture anchor  880  into a first surgical site by contacting suture anchor  880  to the site and applying a rotational torque R15 to handle  810 . The operator then contacts suture anchor  890  to a second surgical site and applies an axial force F15 to knob  836  to drive plunger member  830  distally and deploy suture anchor  890  distally out of channel  824  and into the second surgical site.  
         [0104]    Referring to FIGS. 12, 13A, and  13 B, another suture anchor insertion tool  900  permits arthroscopic insertion of two anchors coupled by a suture to, e.g., attach soft tissue to bone. Insertion tool  900  includes a handle  910  defining a guide slot  940 , an outer tubular member  920  having a first anchor receiver  921  for receiving the first suture anchor  980 , and a plunger member  930  having a second anchor receiver  931  for receiving the second suture anchor  990 . Plunger member  930  is slidably received inside member  920  and is guided by guide slot  940  for inserting second suture anchor  990  into bone.  
         [0105]    Handle  910  has a distal end  911  and a proximal end  913  and defines an interior channel  914  for receiving plunger member  930 . Distal end  911  of handle  910  defines a cutout portion  912  for receiving a proximal end  923  of member  920  in, e.g., a compression fit.  
         [0106]    Guide slot  940  extends through handle  910  to communicate with channel  914 . Guide slot  940  includes a distal lateral extent  942  and a proximally extending longitudinal extent  944 . Lateral extent  942  extends laterally from an end  941  to a junction  943  with longitudinal extent  944 . Lateral extent  942  includes a stop  946  defined in a proximal wall  942 P of slot  942 . Longitudinal extent  944  extends longitudinally along handle  910  from junction  943  to a proximal stop  945 .  
         [0107]    Member  920  has a distal end  921  and a proximal end  923 , and a wall  927  defining an axial channel  924  extending from proximal end  823  to distal end  921 . When proximal end  923  of member  920  is received in cutout portion  912  of handle  910 , axial channel  924  of member  920  communicates with interior channel  914  of handle  910  to form a passage for plunger member  930 . Distal end  921  of member  920  includes suture anchor receiver  928  for non-rotatably mating with first suture anchor  980  having a mating portion  982 , as described above with reference to FIG. 11. Suture anchor  980  also includes a thread  984  for facilitating torsional insertion of suture anchor  980  into bone.  
         [0108]    Plunger member  930  has a distal end  931  and a proximal end  933 , and a wall  937  defining an axial channel  934  extending from proximal end  933  to distal end  931 . Plunger member  930  is dimensioned to slide within axial channel  924  of member  920  and interior channel  914  of handle  910 . Distal end  921  of plunger member  930  includes a suture anchor receiver  938  for non-rotatably mating with second suture anchor  990  having a mating portion  992 , such as with hex couplings as described above. Suture anchor  990  also includes a thread  994  for facilitating torsional insertion of suture anchor  990  into bone. Anchors  980  and  990  are oppositely threaded, for example, thread  984  facilitates torsional insertion of suture anchor  980  into bone when handle  910  is rotated in the direction of arrow R 16 , whereas thread  994  facilitates torsional insertion of suture anchor  990  into bone when handle  910  is rotated in the direction of arrow R 17 .  
         [0109]    Proximal end  933  of plunger member  930  is joined to an actuating button  950  by, e.g., epoxy. Button  950  is slidable within guide slot  940  to extend distal end  931  of plunger member  930  out of channel  924  in member  920 .  
         [0110]    In use, an operator advances tool  800  to a first surgical site and inserts suture anchor  980  into the bone by rotating handle  910  in the direction of arrow R 16 . The operator then withdraws insertion tool  900  away from the first surgical site, releasing anchor  980 , and advances button  950  distally along longitudinal extent  944  to advance plunger member  930  extending suture anchor  990  distally beyond distal end  921  of member  920 . When button  950  reaches junction  943 , the operator advances button  950  laterally within lateral extent  942  and into stop  946  to maintain suture anchor  990  beyond distal end  921  of member  920 . The operator then deploys suture anchor  990  at second surgical site by rotating handle  910  in the direction of arrow R 17 . The opposite rotation used to deploy suture anchor  990  removes windup of the suture that may have occurred during insertion of the first anchor  980 .  
         [0111]    Referring to FIGS.  14 A- 14 C, a pound-in suture anchor  1480  that rotates during insertion into tissue is generally rod-shaped and includes a distal end  1481  capped by a tip  1482  and a proximal end  1483  with a lateral suture eyelet  1484 . Tip  1482  is sufficiently robust to penetrate tissue, e.g., bone. Eyelet  1484  is recessed from the outer circumference of suture anchor  1480  by a pair of recesses  1486  and is dimensioned to pass at least one strand of suture.  
         [0112]    The outer circumference of anchor  1480  has four helical rows  1481   a - 1481   d  of barbed threads  1485 . Each helical row has the same pitch of, e.g., about 2 mm, and is separated from neighboring helical rows by smooth helical flutes  1488 . The helical rows  1481   a - 1481   d  act to cause anchor  1480  to rotate when an axial pound-in force is applied to the anchor to aid in insertion and retention of the anchor in bone. Barbed threads  1485  have distal tapers  1486  and proximal ledges  1487 . Tapers  1486  aid in insertion of the anchor in bone, and ledges  1487  aid in retaining the anchor in bone. Anchor  1480  can be used as the pound-in type anchor of any of the embodiments described above.  
         [0113]    Referring to FIGS.  15 A- 15 C, another embodiment of a pound-in type suture anchor  1580  that rotates during insertion into tissue includes a distal end  1581  capped by a tip  1582  and a proximal end  1583  capped by a proximal protrusion  1500  with a lateral suture eyelet  1584 . Eyelet  1584  is recessed from the outer circumference of tip  1582  by a pair of recesses  1586  and is dimensioned to pass at least one strand of suture. As discussed above with reference to FIG. 14A, anchor  1580  has three helical rows of barbed threads  1585  separated by smooth helical flutes  1588 .  
         [0114]    Referring to FIGS. 16A and 16B, another embodiment of a pound-in type suture anchor  1680  that rotates during insertion into tissue includes a distal end  1681  capped by a blunt tip  1682  and a proximal end  1683  capped by a proximal tubular protrusion  1620 . Protrusion  1620  is banded by a circumferential annular depression  1622  for tying a suture to suture anchor  1680 , as discussed below with reference to FIG. 17A. Tip  1682  is blunt and is suitable for insertion, e.g., into a predrilled hole in bone or other tissue. Anchor  1680  has an annular wall  1610  defining an interior longitudinal channel  1600  that extends from distal end  1681  to proximal end  1683 . Longitudinal channel  1600  receives a guidewire or other orienting member to aid in guiding anchor  1680  to the bone hole. As discussed above with reference to FIG. 14A, the outer circumference of anchor  1680  has four helical rows of barbed threads  1685  separated by smooth helical flutes  1688 .  
         [0115]    FIGS.  17 A- 17 F illustrate various ways of coupling suture to a suture anchor. Referring to FIG. 17A, to couple suture  50  to suture anchor  1680  of FIG. 16A, one end of a length of suture  50   a  is looped around suture anchor  1680  within depression  1622 , and secured by a knot  59 , e.g., a heat sealed Chinese knot. The other end of suture  50   a  is formed into a loop  58  and secured by a knot  59   a , e.g., a heat sealed Chinese knot. Loop  58  advantageously provides a good pulley surface for coupling suture  50  to anchor  1680 .  
         [0116]    Referring to FIG. 17B, a suture anchor  1781  includes a proximal tubular protrusion  1720  banded by a circumferential annular depression  1722  for receiving suture  50 . Tubular protrusion  1720  defines a pair of longitudinal channels  1725  that extend from a proximal face  1724  of the anchor to circumferential annular depression  1722  for receiving suture  50 . Suture  50  passes from proximal face  1724  through longitudinal channel  1725 , loops around annular depression  1722 , and then returns past proximal face  1724  through longitudinal channel  1725 .  
         [0117]    Referring to FIG. 17C, a suture anchor  1782  includes a proximal protrusion  1720  banded by a circumferential annular depression  1722 , and defines a pair of longitudinal holes  1725  that extend from a proximal face  1724  of the anchor to circumferential annular depression  1722 . Holes  1725  are located at opposite edges of protrusion  1720 . A length of suture  50   b  has a pair of ends  555  that each pass through one longitudinal channel  1725  and terminate in a retaining knot  556  located in annular depression  1722  to form a pulley.  
         [0118]    Referring to FIG. 17D, a suture anchor  1783  defines a channel  1727  through which suture  50   c  is threaded. One end of the suture can be fixed to the other suture, e.g., with a Chinese knot  59  (FIG. 17A) to form a loop with the other end of the suture extending from the knot, or the two ends of suture can be knotted together to form a pulley. Likewise, referring to FIG. 17E, a suture anchor  1784  defines a channel  1727   a  through which suture  50   d  is threaded and tied to form a loop or pulley.  
         [0119]    Referring to FIG. 17F, a suture anchor  1785  includes a suture portion  557  that is encased, e.g., during molding of suture anchor  1785 , in proximal end  1731  of the anchor to couple suture  50  to suture anchor  1784 . The coupling methods of FIGS. 17B, 17C,  17 D and  17 F all have the advantage that no suture extends beyond the diameter of the anchor.  
         [0120]    Referring to FIG. 18, an anchor insertion assembly  1810  includes an outer tubular member  1812  defining a lumen  1814 , and an inner member  1816  received within lumen  1814 . Assembly  1810  includes first and second suture anchors  1818 ,  1820 . Anchor  1818  has a proximal break-off hub  1822  received within lumen  1814 , and anchor  1820  is received within lumen  1814  proximal of anchor  1818 . Anchors  1818 ,  1820  are of the pound-in type. Application of an axial force, f 1 , to outer tubular member  1812  is used to implant anchor  1818  into tissue, and application of an axial force, f 2 , to inner member  1816  advances inner member  1816  relative to outer member  1812  to deploy anchor  1820 .  
         [0121]    Referring to FIGS. 19A and 19B, anchor  1818  has a distal end  1830  that tapers to a sharp point  1832 , and a series of stacked, truncated cone shaped elements  1834 . Each element  1834  tapers proximally to a larger outer diameter, with the base outer diameter, OD b , of each element  1834  being larger than the element  1834  immediately distal thereof. Hub  1822  is coupled to proximal element  1834   a  by a thin section  1836  that allows hub  1822  to be broken off from element  1834   a  by application of lateral or tortional (e.g., twisting) force applied by outer member  1812  (FIG. 18). Hub  1822  has a smaller outer diameter than the base outer diameter of section  1834   a  such that a ledge  1838  is defined by section  1834   a  against which the axial force of outer tubular member  1812  can be applied to anchor  1818 .  
         [0122]    Anchor  1818  defines two through holes  1840 ,  1842  and a channel  1844  extending axially between each pair of through holes for receiving suture  1846 . Each element  1834  defines two grooves  1850  that resist any tendency of anchor  1818  to twist during advancement into tissue. (Alternatively, grooves  1850  may be replaced by raised ribs for added strength.) Hub  1822  has a proximal opening  1852  that receives a distal end  1854  of anchor  1820 . Anchor  1820  is identical in design to anchor  1818 , with the exception of having a smaller outer diameter. The smaller outer diameter permits anchor  1820  to fit within outer tubular member lumen  1814 . While anchor  1820  is shown in the figure as smaller than anchor  1818 , it need not be smaller (e.g. anchors  1818  and  1820  may be the same length and/or diameter). Inner member  1816  (FIG. 18) is a solid cylindrical member with a distal notch  1816   a  for receiving break-off hub  1822   a  of anchor  1820 . Inner member  1816  acts against a ledge  1838   a  of anchor  1820  to advance anchor  1820  into tissue.  
         [0123]    Referring particularly to FIG. 19B, from a first suture end  1846   a , suture  1846  extends through hole  1842   a  in anchor  1820 , then through hole  1840   a  in anchor  1820  to form a loop  1848  secured by a Chinese knot  1850 . From knot  1850 , suture  1846  extends distally to anchor  1818  and through hole  1840  to form a loop  1852  secured by a slip knot  1854 . From knot  1854 , suture  1846  extends to hole  1842 , within which a second end  1846   b  of suture  1846  is fixed. While not shown in FIG. 19B, suture  1846  resides within channels  1844  between holes  1842  and  1844 , and between holes  1842   a  and  1844   a , such that in use, the suture located within the tissue remains within the outer diameter of the anchors.  
         [0124]    Referring to FIG. 20, in use, the operator pounds anchor  1818  into bone  1860 . (Alternatively, a hole may be preformed for the anchor, e.g., by drilling.) The engagement of the distal end of outer tube  1812  against the proximal end of anchor  1818  transmits the driving forces to anchor  1818 . Alternatively, if anchor  1818  were reduced in diameter to, e.g., that of anchor  1820 , the driving forces may be transmitted by the engagement of one or more protrusions (e.g., punch  1819 , shown in phantom in FIG. 18) against a proximal end of hub  1822 . Punch  1819  must permit anchor  1820  and inner member  1816  to pass, of course.  
         [0125]    Due to the break-off nature of hub  4822 , outer tubular member  1812  does not need advance as far into bone  1860  to implant anchor  1818  as compared to an anchor having a hub that would need to be advanced into the bone. This has the advantage of limiting possible tissue damage that can occur when the end of an anchor delivery device is advanced into the bone to advance the hub into the bone. By applying a lateral or tortional force to outer tubular member  1812 , the operator breaks off hub  1822  from the remainder of anchor  1818 . Grooves  1850  resist anchor  1818  rotating in the bone as the break-off force is applied. This is particularly useful if the operator employs tortional force due to, e.g., limited space at the surgical site. Hub  1822  remains attached to suture end  1846   b  such that hub  1822  does not become a loose body.  
         [0126]    The operator then advances inner member  1816  relative to outer member  1812  to deploy anchor  1820  at a second location in bone  1860 . (Alternatively, a hole may be preformed for the anchor, e.g., by drilling.) The operator then applies a lateral or tortional force to inner member  1816  to break off hub  1822   a . By then pulling on hub  1822  of anchor  1818 , slip knot  1854  is moved along suture  1846  to tighten suture  1846 , thus, e.g., functioning to securely reattach soft tissue to bone  1860 . The operator then trims suture  1846  near slip knot  1854  and removes hub  1822 . Hub  1822   a  is attached to inner member  1816  (e.g. with adhesive or by a press fit) so that it does not fall out of outer tubular member  1812  into the surgical site.  
         [0127]    A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, surgical site  31  may be a predrilled hole in bone  30 . The various embodiments of pound-in anchors can include a break-off hub. Accordingly, other embodiments are within the scope of the following claims.