Abstract:
Apparatus for attaching a first object to a second object, said apparatus comprising:
       a distal anchor comprising a generally cylindrical body, a distal end and a proximal end, wherein said distal end comprises an inclined distal end surface, and a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body;   a proximal anchor comprising a generally cylindrical body, a distal end and a proximal end, a top surface and a bottom surface, a first vertical bore extending through said generally cylindrical body from said top surface to said bottom surface, perpendicular to the longitudinal axis of the generally cylindrical body, a second vertical bore spaced distally from said first vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore, a third vertical bore spaced distally from said second vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore, and a fourth vertical bore spaced distally from said third vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore; and   a suture having a proximal end and a distal end, with an enlargement formed at said distal end, wherein said suture extends through said vertical bore of said distal anchor, through said fourth vertical bore of said proximal anchor, through said third vertical bore of said proximal anchor, through said second vertical bore of said proximal anchor and through said first vertical bore of said proximal anchor.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATIONS 
       [0001]    This patent application claims benefit of: 
         [0002]    (i) pending prior U.S. Provisional Patent Application Ser. No. 61/866,955, filed Aug. 16, 2013 by Suture Concepts Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR CLOSING A FISSURE IN THE ANNULUS OF AN INTERVERTEBRAL DISC, AND/OR FOR EFFECTING OTHER ANATOMICAL REPAIRS AND/OR FIXATIONS (Attorney&#39;s Docket No. SUTURECONCEPTS-1 PROV); 
         [0003]    (ii) pending prior U.S. Provisional Patent Application Ser. No. 61/915,433, filed Dec. 12, 2013 by Suture Concepts Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR CLOSING A FISSURE IN THE ANNULUS OF AN INTERVERTEBRAL DISC, AND/OR FOR EFFECTING OTHER ANATOMICAL REPAIRS AND/OR FIXATIONS (Attorney&#39;s Docket No. SUTURECONCEPTS-2 PROV); and 
         [0004]    (iii) pending prior U.S. Provisional Patent Application Ser. No. 61/984,431, filed Apr. 25, 2014 by Suture Concepts Inc. and Peter Sorensen et al. for METHOD AND APPARATUS FOR CLOSING A FISSURE IN THE ANNULUS OF AN INTERVERTEBRAL DISC, AND/OR FOR EFFECTING OTHER ANATOMICAL REPAIRS AND/OR FIXATIONS (Attorney&#39;s Docket No. SUTURECONCEPTS-3 PROV). 
         [0005]    The three (3) above-identified patent applications are hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0006]    This invention relates to the treatment of degenerative disc disease in general, and more particularly to methods and apparatus for closing fissures in the annulus of an intervertebral disc. This invention also relates to methods and apparatus for effecting other anatomical repairs and/or fixations. 
       BACKGROUND OF THE INVENTION 
       [0007]    The human spine is a column of articulating vertebrae separated by intervertebral discs. It provides support for the torso, and houses and protects the spinal cord in its spinal canal. 
         [0008]    The human intervertebral disc is an oval-shaped to kidney-shaped structure of variable size depending on its location in the spine. The outer portion of the disc is known as the annulus fibrosus (or anulus fibrosus, annulus fibrosis, anulus fibrosis) or simply “the annulus”. The inner portion of the disc is known as the nucleus pulposis or simply “the nucleus”. 
         [0009]    The annulus is made up of ten to twenty collagen fiber lamellae. The collagen fibers within a given lamella extend parallel to one another. Successive lamellae have their collagen fibers oriented in alternating directions. About 48 percent of the lamellae are incomplete, but this percentage varies with location and it increases with age. On average, the collagen fibers of a given lamella lie at an angle of about sixty degrees to the vertebral axis line, but this too varies with location. The orientations of the lamellae serve to control vertebral motion (i.e., one half of the lamellae tighten to check motion when the vertebra above or below the disc are turned in either direction). 
         [0010]    The annulus contains the nucleus. The nucleus has a consistency generally similar to that of crabmeat. The nucleus serves to transmit and dampen axial loads. A high water content (approximately 70-80 percent) assists the nucleus in this function. The water content has a diurnal variation. The nucleus absorbs water while a person lies recumbent. Activity generates increased axial loads which squeeze water from the disc. The nucleus comprises roughly 50 percent of the entire disc. The nucleus contains cells (chondrocytes and fibrocytes) and proteoglycans (chondroitin sulfate and keratin sulfate). The cell density in the nucleus is on the order of 4,000 cells per microliter. 
         [0011]    The intervertebral disc changes, or “degenerates”, with age. As a person ages, the water content of the disc falls from approximately 85 percent at birth to approximately 70 percent in the elderly. The ratio of chondroitin sulfate to keratin sulfate decreases with age, while the ratio of chondroitin 6 sulfate to chondroitin 4 sulfate increases with age. The distinction between the annulus and the nucleus decreases with age. Generally, disc degeneration is painless. 
         [0012]    Premature or accelerated disc degeneration is known as degenerative disc disease. A large portion of patients suffering from chronic lower back pain are thought to have this condition. As the disc degenerates, the nucleus and annulus functions are compromised. The nucleus becomes thinner and less able to handle compressive loads. The annulus fibers become redundant as the nucleus shrinks. The redundant annular fibers are less effective in controlling vertebral motion. This disc pathology can result in (i) tears of the annulus (both “full-thickness” tears and “partial-thickness” tears) as abnormal loads are transmitted to the annulus and the annulus is subjected to excessive motion between vertebrae, and (ii) disc herniation (i.e., extrusion of the nucleus) through complete (i.e., full-thickness) annular tears. Degenerative disc disease is frequently the cause of substantial pain for a patient. 
         [0013]    Current surgical treatments for disc degeneration are generally “destructive”, in the sense that they generally involve the removal or destruction of disc tissue. 
         [0014]    One group of procedures, which includes microlumbar discectomy, removes the nucleus or a portion of the nucleus. 
         [0015]    A second group of procedures destroys nuclear material. This group includes Chymopapin (an enzyme) injection, laser discectomy, and thermal therapy (i.e., heat treatment to denature proteins in the nucleus). 
         [0016]    The foregoing two groups of procedures compromise the nucleus of the treated disc, and may exacerbate fissures in the annulus while accessing the nucleus. 
         [0017]    A third group of procedures, which includes spinal fusion procedures, either removes the disc or effectively eliminates the disc&#39;s function by connecting together two or more vertebrae, e.g., by “fusing” the vertebrae together with bone. However, such spinal fusion procedures transmit additional stress to the adjacent discs, which typically results in premature degeneration of the adjacent discs over time. 
         [0018]    In general, the “destructive” nature of current surgical treatments for disc degeneration can provide substantial pain relief for the patient, but it can also lead to further disc degeneration over time, which can result in new pain for the patient. By way of example but not limitation, procedures to remove the nucleus or a portion of the nucleus, and procedures to destroy nuclear material, compromise nucleus function and may exacerbate fissures in the annulus while accessing the nucleus, thereby leading to further disc degeneration. By way of further example but not limitation, spinal fusion procedures can induce premature disc degeneration in adjacent intervertebral discs. 
         [0019]    Ideally, disc herniation (i.e., the extrusion of nucleus through full-thickness annular tears) should be treated by closing the fissures in the annulus. However, in practice, this is difficult to achieve. 
         [0020]    By way of example but not limitation, it is difficult to close fissures in the annulus by conventional suturing. For one thing, the annulus is tough and thick and does not lend itself to manual suturing, particularly given the limited access corridors often imposed on the surgeon. For another thing, the loads imposed on the nucleus are large, so that inadequate closure of the fissures can lead to subsequent recurrence of the fissures. Furthermore, the area surrounding the intervertebral disc is crowded with delicate structures (e.g., nerves), so that the use of knots to secure suture can be problematic. 
         [0021]    By way of further example but not limitation, it is difficult to close fissures in the annulus using conventional toggle anchors. More particularly, in U.S. Pat. No. 7,004,970, issued Feb. 28, 2006 to Cauthen III et al., there is disclosed a system for closing fissures in the annulus, wherein the system comprises first and second conventional toggle anchors connected together by filament, and wherein the filament comprises a cinch knot and a cinch line. See, for example, FIGS. 61A, 61B, 62A-62D and 63 of Cauthen III et al. With this system, the first conventional toggle anchor is passed through the annulus and into the nucleus on a first side of a fissure, the second conventional toggle anchor is passed through the annulus and into the nucleus on a second side of the fissure, and then the cinch line is pulled to draw together the two conventional toggle anchors and thereby close the fissure. However, this system suffers from significant drawbacks. First, it is difficult to reliably toggle conventional toggle anchors within the nucleus, which can result in poor setting of the conventional toggle anchors within the intervertebral disc and hence inadequate closure of the fissure. Second, it is difficult to set the cinch knot close to the surface of the annulus, particularly given the limited access corridors often imposed on the surgeon, which can result in inadequate closure of the fissure and interference with the delicate structures around the intervertebral disc, e.g., nerves, etc. Third, the cinch knot can easily slip, thereby undermining the closure of the fissure. For this reason, systems using conventional toggle anchors have achieved limited success in closing fissures within the annulus. 
         [0022]    In Cauthen III et al., there is also disclosed a knotless system for tensioning the filament between the two conventional toggle anchors, wherein enlargements are formed on the filament and are pulled through a narrow opening formed on one of the conventional toggle anchors so as to provide a knotless ratchet securement. However, this knotless ratchet securement is limited to preset tension levels (i.e., it is not continuously adjustable) and has limited holding power, among other things. 
         [0023]    Thus there is a need for a new and improved method and apparatus for closing fissures in the annulus of an intervertebral disc, whereby to treat degenerative disc disease. 
         [0024]    In addition to the foregoing, in many other situations it may be necessary and/or desirable to effect anatomical repairs and/or fixations. 
         [0025]    By way of example but not limitation, two pieces of soft tissue may need to be held in apposition to one another to effect a repair (e.g., so as to close an incision in the skin), or two pieces of cartilage may need to be held in apposition to one another to effect a repair (e.g., so as to close a tear in meniscal cartilage), or two pieces of bone may need to be held in apposition to one another so as to effect a repair (e.g., so as to fuse together bone). 
         [0026]    By way of further example but not limitation, a piece of soft tissue may need to be held in apposition to bone to effect a repair (e.g., so as to attach soft tissue to bone), or a piece of cartilage may need to be held in apposition to bone to effect a repair (e.g., so as to attach labrum to bone or to attach meniscal cartilage to bone). 
         [0027]    By way of further example but not limitation, a prosthesis may need to be held in apposition to soft tissue or bone, or soft tissue or bone may need to be held in apposition to a prosthesis, and/or any first object may need to be held in apposition to any second object. 
         [0028]    In these and other situations, it would also be advantageous to provide a new and improved method and apparatus for effecting anatomical repairs and/or fixations. 
       SUMMARY OF THE INVENTION 
       [0029]    The present invention provides a new and improved method and apparatus for closing fissures in the annulus of an intervertebral disc, whereby to treat degenerative disc disease. 
         [0030]    The present invention also provides a new and improved method and apparatus for effecting other anatomical repairs and/or fixations. 
         [0031]    More particularly, among other things, the present invention facilitates the reconstruction of the annulus by providing a novel method and apparatus for closing fissures in the annulus of an intervertebral disc. Among other things, such reconstruction prevents recurrent herniation following a microlumbar discectomy. The invention may also be used in the treatment of herniated discs, annular tears of the disc, and/or other disc degeneration, while enabling surgeons to preserve (or even augment or replace) the contained nucleus. The method and apparatus of the present invention may be used to treat discs throughout the spine, including the cervical, thoracic, and lumbar spines of humans and animals. 
         [0032]    Preferred embodiments of the present invention include a flexible longitudinal fixation component (e.g., a filament) extending across a soft tissue defect, such as a fissure in the annulus. A pair of transverse anchor components (e.g., bar anchors), selectively connected to the flexible longitudinal fixation component, are preferably placed behind an inner layer of the annulus on opposite sides of the fissure, so as to anchor the flexible longitudinal fixation component to the annulus, with the flexible longitudinal fixation component extending axially through the annulus and laterally across the fissure so as to hold the fissure closed, whereby to prevent nucleus material from passing out the fissure and pressing on the adjacent nerves, including the spinal cord. Significantly, with the present invention, the transverse anchor components can be passed through the annulus and into the nucleus of the intervertebral disc using a direct “needle plunge” action, which facilitates passage through the tough, thick annulus, and which is highly compatible with the limited access corridors often imposed on the surgeon. Furthermore, the present invention allows the tension of the flexible longitudinal fixation component to be adjusted as necessary so as to effect proper fissure closure, and then set in place without requiring the use of knots. 
         [0033]    And the flexible longitudinal fixation component (e.g., the filament) may be anchored to one of the upper and lower vertebral bodies adjacent to the intervertebral disc being treated. 
         [0034]    In one preferred form of the present invention, two novel transverse anchor components (e.g., bar anchors) are provided. One novel anchor component (sometimes hereinafter referred to as the distal anchor) is provided with an associated inserter and the two, in conjunction with the flexible longitudinal fixation component (e.g., filament) provide enhanced toggling of the anchor component within dense structures such as a vertebral body and/or an intervertebral disc. The second novel anchor component (sometimes hereinafter referred to as the proximal anchor) is provided with novel means for knotlessly securing the flexible longitudinal fixation component to that anchor component, whereby to allow the tension of the flexible longitudinal fixation component to be reliably set between the two anchor components without requiring the use of knots. 
         [0035]    The present invention may also be used to effect other anatomical repairs and/or fixations. 
         [0036]    By way of example but not limitation, the present invention may be used to hold two pieces of soft tissue in apposition to one another to effect a repair (e.g., so as to close an incision in the skin), or the present invention may be used to hold two pieces of cartilage in apposition to one another to effect a repair (e.g., so as to close a tear in meniscal cartilage), or the present invention may be used to hold two pieces of bone in apposition to one another so as to effect a repair (e.g., so as to fuse together bone). 
         [0037]    By way of further example but not limitation, the present invention may be used to hold a piece of soft tissue in apposition to bone to effect a repair (e.g., so as to attach soft tissue to bone), or the present invention may be used to hold a piece of cartilage in apposition to bone to effect a repair (e.g., so as to attach labrum to bone or to attach meniscal cartilage to bone). 
         [0038]    By way of further example but not limitation, the present invention may be used to hold a prosthesis in apposition to soft tissue or bone, or to hold soft tissue or bone in apposition to a prosthesis, and/or to hold any first object in apposition to any second object. 
         [0039]    In one preferred form of the present invention, there is provided apparatus for attaching a first object to a second object, said apparatus comprising: 
         [0040]    a distal anchor comprising a generally cylindrical body, a distal end and a proximal end, wherein said distal end comprises an inclined distal end surface, and a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body; 
         [0041]    a proximal anchor comprising a generally cylindrical body, a distal end and a proximal end, a top surface and a bottom surface, a first vertical bore extending through said generally cylindrical body from said top surface to said bottom surface, perpendicular to the longitudinal axis of the generally cylindrical body, a second vertical bore spaced distally from said first vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore, a third vertical bore spaced distally from said second vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore, and a fourth vertical bore spaced distally from said third vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore; and 
         [0042]    a suture having a proximal end and a distal end, with an enlargement formed at said distal end, wherein said suture extends through said vertical bore of said distal anchor, through said fourth vertical bore of said proximal anchor, through said third vertical bore of said proximal anchor, through said second vertical bore of said proximal anchor and through said first vertical bore of said proximal anchor. 
         [0043]    In another preferred form of the present invention, there is provided a method for connecting a first object to a second object, said method comprising: 
         [0044]    providing apparatus comprising:
       a distal anchor comprising a generally cylindrical body, a distal end and a proximal end, wherein said distal end comprises an inclined distal end surface, and a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body;   a proximal anchor comprising a generally cylindrical body, a distal end and a proximal end, a top surface and a bottom surface, a first vertical bore extending through said generally cylindrical body from said top surface to said bottom surface, perpendicular to the longitudinal axis of the generally cylindrical body, a second vertical bore spaced distally from said first vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore, a third vertical bore spaced distally from said second vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore, and a fourth vertical bore spaced distally from said third vertical bore and extending from said top surface to said bottom surface parallel to said first vertical bore; and   a suture having a proximal end and a distal end, with an enlargement formed at said distal end, wherein said suture extends through said vertical bore of said distal anchor, through said fourth vertical bore of said proximal anchor, through said third vertical bore of said proximal anchor, through said second vertical bore of said proximal anchor and through said first vertical bore of said proximal anchor;       
 
         [0048]    advancing said distal anchor into the first object, with said suture and said enlargement advancing with said distal anchor; 
         [0049]    while holding said suture and said enlargement in place, further advancing said distal anchor so that said inclined distal end surface of said distal anchor engages said enlargement and causes said distal anchor to turn relative to the first object; 
         [0050]    advancing said proximal anchor into the second object; 
         [0051]    pulling proximally on the portion of said suture extending between said second vertical bore of said proximal anchor and said third vertical bore of said proximal anchor so as to cause said proximal anchor to turn relative to the second object; 
         [0052]    passing said proximal end of said suture between (i) the portion of said suture extending between said second vertical bore of said proximal anchor and said third vertical bore of said proximal anchor and (ii) said proximal anchor, so as to form a half hitch in said suture; and 
         [0053]    pulling proximally on said proximal end of said suture so as to set said half hitch. 
         [0054]    In another preferred form of the present invention, there is provided apparatus for attaching a suture to an object, said apparatus comprising: 
         [0055]    an anchor comprising a generally cylindrical body, a distal end and a proximal end, wherein said distal end comprises an inclined distal end surface, and a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body; and 
         [0056]    a suture having a proximal end and a distal end, with an enlargement formed at said distal end, wherein said suture extends through said vertical bore of said anchor. 
         [0057]    In another preferred form of the present invention, there is provided a method for attaching a suture to an object, said method comprising: 
         [0058]    providing apparatus comprising:
       an anchor comprising a generally cylindrical body, a distal end and a proximal end, wherein said distal end comprises an inclined distal end surface, and a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body; and   a suture having a proximal end and a distal end, with an enlargement formed at said distal end, wherein said suture extends through said vertical bore of said anchor;       
 
         [0061]    advancing said anchor into said object, with said suture and said enlargement advancing with said anchor; 
         [0062]    while holding said suture and said enlargement in place, further advancing said anchor so that said inclined distal end surface of said anchor engages said enlargement and causes said anchor to turn relative to said object. 
         [0063]    In another preferred form of the present invention, there is provided apparatus for attaching a suture to an object, said apparatus comprising: 
         [0064]    an anchor comprising a generally cylindrical body, a distal end and a proximal end, a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body, a recess formed on one side of said generally cylindrical body and a U-shaped slot formed on the opposing side of said generally cylindrical body whereby to form a flexible finger extending distally within said generally cylindrical body, and further wherein said distal end of said finger is spaced from an opposing portion of said generally cylindrical body; and 
         [0065]    a suture extending through said vertical bore, said recess and said U-shaped slot. 
         [0066]    In another preferred form of the present invention, there is provided a method for attaching a suture to an object, said method comprising 
         [0067]    providing apparatus comprising:
       an anchor comprising a generally cylindrical body, a distal end and a proximal end, a vertical bore extending through said generally cylindrical body, perpendicular to the longitudinal axis of said generally cylindrical body, a recess formed on one side of said generally cylindrical body and a U-shaped slot formed on the opposing side of said generally cylindrical body whereby to form a flexible finger extending distally within said generally cylindrical body, and further wherein said distal end of said finger is spaced from an opposing portion of said generally cylindrical body; and   a suture extending through said vertical bore, said recess and said U-shaped slot;       
 
         [0070]    advancing said anchor into the object; and 
         [0071]    pulling on said proximal end of said suture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0072]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
           [0073]      FIGS. 1 and 2  are schematic views showing a novel system for closing a fissure in the annulus of an intervertebral disc, whereby to treat degenerative disc disease, and/or for effecting other anatomical repairs and/or fixations; 
           [0074]      FIG. 3  is a schematic view showing the anchor assembly of the novel system of  FIGS. 1 and 2 ; 
           [0075]      FIG. 4  is a schematic view showing the inserter of the novel system of  FIGS. 1 and 2 ; 
           [0076]      FIGS. 5-25  are schematic views showing further details of the anchor assembly of  FIG. 3 ; 
           [0077]      FIGS. 26, 27, 27A and 28-31  are schematic views showing further details of the inserter of  FIG. 4 ; 
           [0078]      FIGS. 32-38 and 38A-38G  are schematic views showing use of the novel system of  FIGS. 1 and 2  to close a fissure in the annulus of an intervertebral disc; 
           [0079]      FIGS. 39-41  are schematic views showing a tensioner which may be used in conjunction with the novel system of  FIGS. 1 and 2 ; 
           [0080]      FIGS. 41A and 41B  are schematic views showing another form of tensioner which may be used in conjunction with the novel system of  FIGS. 1 and 2 ; 
           [0081]      FIGS. 42-51  are schematic views showing examples of additional anatomical repairs and/or fixations which may be effected using the present invention; 
           [0082]      FIG. 52  is a schematic view showing a sensory nerve stimulator (SNS) lead positioned within a spine; 
           [0083]      FIGS. 53-62  are schematic views showing how the novel system may be used to hold an SNS lead in position within anatomy; 
           [0084]      FIGS. 63-70  are schematic views showing various ways in which the novel system may be used to secure an SNS lead adjacent to spinal structures; 
           [0085]      FIGS. 71 and 72  are schematic views showing a proximal anchor comprising a flexible finger; 
           [0086]      FIG. 73  is a schematic view showing a single anchor system formed in accordance with the present invention; 
           [0087]      FIGS. 74-85  are schematic views showing another single anchor system formed in accordance with the present invention, wherein the system comprises an anchor comprising a flexible finger; and 
           [0088]      FIG. 86  is a schematic view showing an alternative form of inserter with impulse driver. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0089]    The present invention comprises the provision and use of a novel system for closing a fissure in the annulus of an intervertebral disc, whereby to treat degenerative disc disease. 
         [0090]    The present invention also provides a new and improved method and apparatus for effecting other anatomical repairs and/or fixations. 
       Novel System for Closing a Fissure in the Annulus of an Intervertebral Disc and/or for Effecting Other Anatomical Repairs and/or Fixations 
       [0091]    More particularly, and looking first at  FIGS. 1 and 2 , there is shown a novel system  5  for, among other things, closing a fissure in the annulus of an intervertebral disc. System  5  generally comprises an anchor assembly  10  ( FIGS. 1-3 ) and an inserter  15  ( FIGS. 1, 2 and 4 ). 
       Novel Anchor Assembly 
       [0092]    Looking now at  FIGS. 3 and 5-8 , anchor assembly  10  generally comprises a distal anchor  20 , a proximal anchor  25 , and a suture  30  connecting distal anchor  20  and proximal anchor  25 . 
       Novel Distal Anchor 
       [0093]    As seen in  FIGS. 5, 6 and 9-16 , distal anchor  20  comprises a generally cylindrical body  35  having a distal end  40 , a proximal end  45  and a generally circular side wall  50 . Distal end  40  terminates in a flat distal surface  55  and an inclined distal surface  60 . Flat distal surface  55  is preferably sufficiently large to render distal end  40  of distal anchor  20  substantially blunt. Inclined distal surface  60  is pitched at an appropriate angle (e.g., 30 degrees, 45 degrees, etc.) so as to cause distal anchor  20  to turn during deployment, as will hereinafter be discussed. Proximal end  45  terminates in an inclined proximal surface  65 . Inclined proximal surface  65  is pitched at an appropriate angle (e.g., 70 degrees) so as to cause distal anchor  20  to set during deployment, as will hereinafter be discussed. A vertical bore  70  passes through distal anchor  20 . Vertical bore  70  is sized to slidably receive suture  30  therein. A horizontal slot  75  extends between inclined distal end surface  60  and vertical bore  70 . Horizontal slot  75  is preferably also sized to slidably receive suture  30  therein and helps keep distal anchor  20  and suture  30  from binding when they are disposed within inserter  15 . A pair of distal notches  80  are preferably formed in distal end  40  and intersect inclined distal surface  60 . A proximal notch  85  is preferably formed near to, but proximal to, proximal end surface  65 . Proximal notch  85  cooperates with inclined proximal surface  65  to form a pointed heel  87  which enhances setting of distal anchor  20 , as will hereinafter be discussed. In one preferred form of the invention, distal anchor  20  is formed out of PEEK or carbon-filled PEEK, has a length of about 0.20 inch and a width of about 0.063 inch. However, it should be appreciated that distal anchor  20  may also be formed out of other suitable materials and/or have other dimensions. 
       Novel Proximal Anchor 
       [0094]    As seen in  FIGS. 7, 8 and 17-25 , proximal anchor  25  comprises a generally cylindrical body  90  having a distal end  95 , a proximal end  100  and a generally circular side wall  105 . Distal end  95  terminates in a flat distal surface  110  and an inclined distal surface  115 . Flat distal surface  110  is preferably sufficiently large to render distal end  95  of proximal anchor  25  substantially blunt. Inclined distal surface  115  is pitched at an appropriate angle (e.g., 30 degrees, 45 degrees, etc.) so as to assist proximal anchor  25  in turning during deployment, as will hereinafter be discussed. Proximal end  100  terminates in an inclined proximal surface  120 . Inclined proximal surface  120  is pitched at an appropriate angle (e.g., 20 degrees from the vertical) so as to assist proximal anchor  25  in setting during deployment, as will hereinafter be discussed. Four vertical bores  125 ,  130 ,  135  and  140  pass through proximal anchor  25 . Vertical bores  125 ,  130 ,  135  and  140  are sized to slidably receive suture  30  therein. A top horizontal slot  145  extends between vertical bores  130  and  135 . Top horizontal slot  145  is preferably also sized to slidably receive suture  30  therein and helps keep proximal anchor  25  and suture  30  from binding when they are disposed within inserter  15 . A bottom horizontal slot  150  extends between vertical bores  125  and  130 . If desired, bottom horizontal slot  150  may be stepped, and may comprise a wider outer portion  155  and a narrower inner portion  160 . Wider outer portion  155  may be sized to slidingly receive suture  30  therein so as to help keep proximal anchor  25  and suture  30  from binding when they are disposed within inserter  15 , but narrower inner portion  160  may be sized to snugly receive suture  30  therein, whereby to provide a light hold on suture  30  when suture  30  is disposed therein. A bottom horizontal slot  165  extends between vertical bores  135  and  140 . If desired, bottom horizontal slot  165  may also be stepped, and may comprise a wider outer portion  170  and a narrower inner portion  175 . Wider outer portion  170  may be sized to slidingly receive suture  30  therein so as to help keep proximal anchor  25  and suture  30  from binding when they are disposed within inserter  15 , but narrower inner portion  175  may be sized to snugly receive suture  30  therein, whereby to provide a light hold on suture  30  when suture  30  is disposed therein. 
       The Suture 
       [0095]    As seen in  FIGS. 3 and 5-8 , suture  30  has a distal end  180  terminating in large ball (or knot)  185  and a proximal end  190 . As seen in  FIG. 6 , suture  30  is passed through distal anchor  20  so that the suture extends along horizontal slot  75  of distal anchor  20  and up vertical bore  70  of distal anchor  20 . Note that when suture  30  is passed through distal anchor  20  in this manner, distal anchor  20  may be slid along suture  30 . As seen in  FIG. 8 , suture  30  is also passed through proximal anchor  25  so that the suture extends down vertical bore  140 , along wider outer portion  170  of bottom horizontal slot  165 , up vertical bore  135 , forms a loop  320  above top horizontal slot  145 , down vertical bore  130 , along wider outer portion  155  of bottom horizontal slot  150 , and up vertical bore  125 . Note that when suture  30  is passed through proximal anchor  25  in this manner, proximal anchor  25  may be slid along suture  30 , albeit with some effort due to the serpentine path which suture  30  follows through proximal anchor  25 . Note also that, if bottom horizontal slot  165  comprises a narrower inner portion  175  and/or if bottom horizontal slot  150  comprises a narrower inner portion  160 , a small amount of additional impedance may be introduced into the system when suture  30  is drawn into narrower inner portion  175  of bottom horizontal slot  165  and/or suture  30  is drawn into narrower inner portion  160  of bottom horizontal slot  150 . In addition, it should be appreciated that while top horizontal slot  145  of proximal anchor  25  is sized to slidingly receive one strand of suture  30  therein, two or more overlapping strands of suture  30  will form a construct of greater diameter which may be snugly received within top horizontal slot  145 , which may also provide a light hold on the two or more overlapping strands of suture when the two or more overlapping strands of suture are disposed within top horizontal slot  145 . 
       The Inserter 
       [0096]    As seen in  FIGS. 4 and 26, 27 and 28 , inserter  15  generally comprises a shaft  195 , a handle  200  and a pushrod  205 . 
         [0097]    Shaft  195  generally comprises a hollow tube having a distal end  210 , a proximal end  215  and a lumen  220  extending therebetween. Distal end  210  of shaft  195  terminates in a sharp point  225 . A slot  227  is formed in distal end  210  of shaft  195  and may terminate in a shoulder  228 . Alternatively, and more preferably, slot  227  extends proximally along shaft  195  so that it is coextensive with a slot  229  formed in inserter  15  ( FIG. 26 ), whereby to allow suture  30  to separate from inserter  15  after distal anchor  20  and proximal anchor  25  have been set. Lumen  220  is sized to slidably receive distal anchor  20  ( FIG. 28 ) and proximal anchor  25  (as will hereinafter be discussed). A mount  230  is secured to proximal end  215  of shaft  195 . 
         [0098]    Handle  200  comprises a distal end  235 , a proximal end  240 , and a bore  245  extending therebetween. A first counterbore  250  is formed at the distal end of handle  200 , and a second counterbore  255  is formed just proximal to first counterbore  250 , with first counterbore  250  being sized to receive shaft  195  and second counterbore  255  being sized to receive mount  230 , whereby to secure shaft  195  to handle  200 . A third counterbore  260  is formed at the proximal end of handle  200 . A groove  265  is formed on the top side of handle  200  for receiving proximal anchor  25  ( FIG. 27 ). Groove  265  communicates with bore  245  via a passageway  270 , whereby to allow proximal anchor  25  to be advanced into bore  245 , as will hereinafter be discussed. Another groove  275  is formed on the top side of handle  200  for slidably receiving a suture sled  280 . Suture sled  280  is biased proximally by a spring  285 . Suture sled  280  includes a pair of suture cleats  290  for releasably securing loop  320  of suture  30  to suture sled  280 , as will hereinafter be discussed. 
         [0099]    Pushrod  205  comprises a pusher  295  which is sized to be slidably received within bore  245  of handle  200  and lumen  220  of shaft  195 . Pusher  295  comprises a distal end  300  ( FIG. 28 ) and a proximal end  305  ( FIG. 27 ). Distal end  300  of pusher  295  is preferably rounded so as to facilitate turning of distal anchor  20  and/or proximal anchor  25  when they are advanced out of shaft  195  of inserter  15 , as will hereinafter be discussed. A thumb button  310  is secured to proximal end  305  of pusher  295 , whereby to allow pusher  295  to be advanced distally by pressing on thumb button  310 . Alternatively, thumb button  310  may be used to retract pusher  295 , e.g., by gripping thumb button  310  between the thumb and forefinger of the user and pulling proximally, whereby to retract pusher  295  proximally. A removable stop  315  ( FIG. 27A ) may be fitted about thumb button  310 , proximal to handle  200 , so as to prevent distal movement of thumb button  310  and hence prevent distal movement of pusher  295 . 
         [0100]    Prior to use, anchor assembly  10  is mounted to inserter  15 . More particularly, distal anchor  20  is loaded into distal end  210  of shaft  195  so that suture  30  extends out slot  227  of shaft  195  ( FIG. 28 ). Proximal anchor  25  is loaded into groove  265  of handle  200 , suture  30  is drawn taut by pulling on loop  320 , and then loop  320  of suture  30  is secured to suture cleats  290 . Note that loop  320  is the portion of suture  30  which extends between where the suture exits vertical bore  135  of proximal anchor  25  and re-enters vertical bore  130  of proximal anchor  25 . Pushrod  205  is inserted into bore  245  of handle  200  and lumen  220  of shaft  195  until removable stop  315  engages the proximal end of handle  200 . At this point, distal end  300  of pusher  295  abuts distal anchor  20  ( FIG. 28 ). 
         [0101]    Preferably suture assembly  10  is mounted to inserter  15  at the time of manufacture and prior to packaging and sterilization, although suture assembly  10  may also be mounted to inserter  15  at the time of use if desired. 
       Exemplary Use of the Novel System to Close a Fissure in the Annulus of an Intervertebral Disc 
       [0102]    In use, in order to close a fissure in the annulus of an intervertebral disc, distal anchor  20  is intended to be positioned on one side of a fissure, proximal anchor  25  is intended to be positioned on another side of the fissure, and suture  30  is thereafter tensioned so as to close the fissure, whereby to treat degenerative disc disease. 
         [0103]    By way of example but not limitation, and looking now at  FIG. 32 , distal anchor  20  may be passed through the annulus of an intervertebral disc  325  at a location  330  on one side of a fissure  335 , and proximal anchor  25  may be passed through the annulus of the same intervertebral disc  325  at a location  340  on the opposite side of a fissure  335 , so that the suture  30  spans fissure  335  and holds it closed. 
         [0104]    By way of further example but not limitation, and looking now at  FIG. 33 , distal anchor  20  may be inserted into a vertebral body  345  adjacent to an intervertebral disc  325  having a fissure  335 , and proximal anchor  25  may be passed through the annulus of that intervertebral disc  325  at a location  340  on the opposite side of a fissure  335 , so that the suture  30  spans fissure  335  and holds it closed. Where distal anchor  320  is to be inserted into vertebral body  345 , a hole may be pre-formed in the vertebral body (e.g., by drilling, tapping, punching, etc.). 
         [0105]    For purposes of illustrating the present invention, an annulus reconstruction will now be discussed in the context of positioning distal anchor  20  in a vertebral body and proximal anchor  25  in the intervertebral disc. 
         [0106]    More particularly, and looking now at  FIGS. 34-38 , a hole  350  is formed (e.g., by drilling, tapping, punching, etc.) in a vertebral body  345  ( FIG. 34 ), the distal end of shaft  195  is inserted into hole  350  to an appropriate depth ( FIG. 35 ), and then removable stop  315  ( FIG. 29 ) is removed from thumb button  310 . Then thumb button  310  is advanced toward handle  200 , causing the distal end of pusher  295  to advance distal anchor  20  out of shaft  195  ( FIG. 36 ). Note that as distal anchor  20  is advanced out of shaft  195 , suture sled  280  moves distally along handle  200 , against the power of spring  285 , thereby allowing suture  30  (and hence ball  185  set at the distal end of suture  30 ) to also move distally with distal anchor  20 . As thumb button  310  continues to advance distally toward handle  200 , suture sled  280  reaches the end of its stroke in groove  275 , thereby preventing further distal movement of suture  30  (and hence preventing further distal movement of ball  185  set at the distal end of suture  30 ). See  FIG. 37 . Thereafter, continued advancement of thumb button  310  toward handle  200  causes distal anchor  20  to pivot on ball  185  as distal inclined surface  60  of distal anchor  20  rides upward on ball  185 , thereby causing distal anchor  20  to rotate within the bone ( FIG. 38 ). In essence, as pusher  295  forces distal anchor  20  against the now-stationary ball  185 , the camming engagement of inclined distal surface  60  of distal anchor  20  with ball  185  causes distal anchor  20  to turn within vertebral body  345 . Thus, the “throw” of suture sled  280  effectively sets the depth of distal anchor  20 , since it effectively sets the position of ball  185  within the vertebral body  345 . Inserter  15  is then moved proximally so as to apply a proximal force to distal anchor  20  via suture  30 , whereby to set distal anchor  20  into vertebral body  345 . Among other things, the pointed heel  87  formed by inclined proximal surface  65  and proximal notch  85  is set into the vertebral body, whereby to facilitate setting of distal anchor  20  as suture  30  is pulled proximally. This completes setting of distal anchor  20 . 
         [0107]    In this respect it should be appreciated that the provision of the novel apparatus of the present invention (i.e., distal anchor  20 , suture  30  and inserter  15 ) provides a significant advantage over conventional toggle anchors of the prior art, since the present invention permits the toggle-type distal anchor  20  to be reliably toggled and set in dense tissue such as an intervertebral body and/or an intervertebral disc. As noted above, conventional toggle-type anchors have had limited success when set within the interior of tissue in general, and particularly when set within the interior of dense tissue such as an intervertebral body and/or an intervertebral disc, since they provide inconsistent toggling and low pull-out strengths. By contrast, with the present invention, the unique camming engagement of inclined distal surface  60  of distal anchor  20  with the restrained ball  85  causes distal anchor  20  to turn even when it is within the interior of dense tissue such as an intervertebral body and/or an intervertebral disc. Furthermore, the pointed heel  87  of distal anchor  20  facilitates setting of the anchor when suture  30  is tensioned. 
         [0108]    Thereafter, loop  320  of suture  30  is released from suture cleats  290 , pushrod  205  is removed from shaft  195  and handle  200 , and inserter  15  is withdrawn from the bone (if it has not already been withdrawn from the bone). As this occurs, proximal anchor  25  is drawn distally through passageway  270  and into bore  245  in handle  200  (due to the fact that proximal anchor  25  encounters some impedance to sliding along suture  30  since suture  30  follows a serpentine path through proximal anchor  25 , and due to the fact that inserter  15  is being withdrawn proximally). 
         [0109]    Then removable stop  315  is replaced on thumb button  310 , and pushrod  205  is advanced into bore  245  of handle  200  and into lumen  220  of shaft  195 . This action advances proximal anchor  25  along lumen  220  of shaft  195 . Pushrod  205  is advanced until removable stop  315  engages the proximal end of handle  200 . At this point, proximal anchor  25  is disposed in the distal end of shaft  195 , but is prevented from being ejected out of the distal end of shaft  195  due to the engagement of removable stop  315  with the proximal end of handle  200 . 
         [0110]    Next, shaft  195  of inserter  15  is inserted through the annulus on the far side of the fissure, so that suture  30  spans the fissure. See  FIG. 38A . Then removable stop  315  is removed from thumb button  310 , and thumb button  310  is advanced distally so as to cause pusher  295  to eject proximal anchor  25  out of shaft  195  and into the nucleus of the intervertebral disc. As this occurs, the geometry of proximal anchor  25  and the tension on suture  30  causes proximal anchor  25  to begin turning within the nucleus of the intervertebral disc. See  FIG. 38B . Next, shaft  195  of inserter  15  is removed from the annulus, and then loop  320  of suture  30  is pulled proximally, causing suture  30  to be pulled taut, whereby to cause proximal anchor  25  to turn further within the nucleus. Where horizontal slot  165  includes a narrower inner portion  175 , pulling proximally on loop  320  of suture  30  also causes suture  30  to be drawn into narrower inner portion  175  of bottom horizontal slot  165 . This action can introduce additional impedance into the system, and this combined impedance (i.e., the combined impedance provided by (i) the serpentine path of suture  30  through proximal anchor  25 , and (ii) the light hold imposed on the suture by narrower inner portion  175  of bottom horizontal slot  165 ) is sufficient to temporarily hold suture  30  to proximal anchor  25 . See  FIG. 38C . Thereafter, the proximal end  190  of suture  30  is pulled lightly so as to close down loop  320  of suture  30  somewhat. See  FIG. 38D . Then proximal end  190  of suture  30  is passed through loop  320  of suture  30 , whereby to form a so-called “half-hitch” configuration. See  FIG. 38E . Next, proximal end  190  of suture  30  is pulled so as to draw loop  320  of suture  30  down into the nucleus of the intervertebral disc. See  FIG. 38F . Pulling continues until the half-hitch configuration of loop  320  and proximal end  190  of suture  30  are drawn into top horizontal slot  145  of proximal anchor  25 , i.e., so that the aforementioned half-hitch is disposed in top horizontal slot  145  of proximal anchor  25 , whereby to prevent the half-hitch from slipping through itself and hence securing suture  30  to proximal anchor  25 . As this occurs, suture  30  is also pulled into bottom horizontal slot  150  and, where bottom horizontal slot  150  includes narrower inner portion  160 , into the narrower inner portion  160  of bottom horizontal slot  150 , whereby to further hold suture  30  to proximal anchor  25 . See  FIG. 38G . 
         [0111]    The proximal end  190  of suture  30  may then be trimmed away, whereby to complete the repair. 
         [0112]    In this respect it should be appreciated that the unique construction of proximal anchor  25  provides a significant advantage over the conventional toggle anchors of the prior art, since it provides novel means for knotlessly securing suture  30  to proximal anchor  25 , whereby to allow the tension of suture  30  to be reliably set between distal anchor  20  and proximal anchor  25 . Significantly, the novel construction provided by proximal anchor  25  provides a unique solution to the problem of knotlessly securing suture to an anchor. More particularly, the knotless securement mechanism of proximal anchor  25  avoids the deficiencies of prior art toggle anchor systems using cinch knots (see Cauthen III et al. as discussed above) and/or filament enlargements/anchor narrowings (see Cauthen III et al. as discussed above). 
         [0113]    In addition, the knotless securement mechanism of proximal anchor  25  provides a significant improvement over the prior art serpentine suture securement mechanisms sometimes found in prior art bone anchors. More particularly, various prior art bone anchors (e.g., screw-type bone anchors) have previously attempted to use serpentine passageways through the bone anchor to knotlessly secure a suture to the bone anchor. However, such prior art serpentine suture securement mechanisms have traditionally required the designer to choose between low holding strength (but relative ease in pulling the suture through the serpentine passageways) or high holding strength (and significant difficulty in pulling the suture through the serpentine passageways). The present invention avoids this problem, providing both high holding strength and relative ease of pulling the suture through the serpentine passageways, by (i) allowing the suture to be accessed at a midpoint within the anchor&#39;s serpentine pathway (e.g., by pulling on loop  320 ), and (ii) providing additional holding means to supplement the holding power of the serpentine suture pathway (i.e., the aforementioned half-hitch and, to a significantly lesser extent, the friction fit of suture  30  within narrower inner portion  175  of bottom horizontal slot  165  and narrower inner portion  160  of bottom horizontal slot  150  (to the extent that bottom horizontal slot  165  comprises a narrower inner portion  175  and bottom horizontal slot  150  comprises a narrower inner portion  160 ). 
         [0114]    Thus, with the present invention, the distal anchor  20  is set into tissue on one side of the fissure, the proximal anchor is deployed into tissue on the other side of the fissure, and then the suture is appropriately tensioned and made fast to the proximal anchor, whereby to effect the repair with the degree of tension selected by the user. Furthermore, with the present invention, the distal anchor can be reliably turned and set within the interior of relatively dense tissue such as bone (as well as within the interior of other tissue) due to its unique construction and deployment mechanism. And with the present invention, the proximal anchor is capable of providing high holding strengths, e.g., on the order of 16 pounds of holding strength. In this respect it should be appreciated that proximal anchor  25  is held to suture  30  to a large extent by the impedance provided by the half-hitch construct (which is aided against slipping by virtue of its disposition in top horizontal slot  145 ), and to a lesser extent by the serpentine suture path through proximal anchor  25 , and to a much smaller extent by the light hold imposed on suture  30  by narrower inner portion  175  of bottom horizontal slot  165  and narrower inner portion  155  of bottom horizontal slot  150  (to the extent that bottom horizontal slot  165  comprises a narrower inner portion  175  and bottom horizontal slot  150  comprises a narrower inner portion  160 ). 
         [0115]    Note that where bottom horizontal slot  165  comprises a narrower inner portion  175 , the hold imposed on suture  30  by narrower inner portion  175  of bottom horizontal slot  165  may be relatively nominal, inasmuch as it provides a useful impedance on suture  30  only during the brief period of time that loop  320  is being reduced and the aforementioned half-hitch is being formed—after loop  320  has been reduced and the aforementioned half-hitch has been set, the significant holding power on suture  30  is provided by the half-hitch construct and the serpentine suture path extending through proximal anchor  25 . In this respect it should also be appreciated that, where bottom horizontal slot  165  comprises a narrower inner portion  175 , and during the brief period of time that narrower inner portion  175  is providing a useful impedance on suture  30 , the patient is lying stationary on the operating table and only a nominal load is imposed on the suture—unlike when the patient is upright and moving about, when a substantial load is imposed on the suture. 
         [0116]    By way of example but not limitation, in one form of the present invention, where bottom horizontal slot  165  comprises a narrower inner portion  175  and bottom horizontal slot  150  comprises a narrower inner portion  160 , the serpentine suture path through proximal anchor  25 , plus the light impedance imposed on suture  30  by narrower inner portion  175  of bottom horizontal slot  165  and narrower inner portion  155  of bottom horizontal slot  150 , collectively provide about 4-6 pounds of holding strength, and the half-hitch construct of proximal end  190  of suture  30  passing through loop  320 , with the half-hitch construct being drawn into top horizontal slot  145  of proximal anchor  25 , brings the total holding strength to about 16 pounds of holding strength. 
       Tensioner(s) which May be Used in Conjunction with the Novel System 
       [0117]    It will be appreciated that, due to the tortuous path of suture  30  through proximal anchor  25 , as well as the need to pull the half-hitch construct into top horizontal slot  145  and, where bottom horizontal slot  165  comprises a narrower inner portion  175  and bottom horizontal slot  150  comprises a narrower inner portion  160 , to pull suture  30  into the narrower inner portion  175  of bottom horizontal slot  165  and narrower inner portion  160  of bottom horizontal slot  150 , substantial force must be applied to the proximal end of suture  30  in order to pull the length of suture between the anchors  20 ,  25  taut and secure the suture in position. This level of force is significantly greater than the level of force required to set distal anchor  20 . Where the annulus of the vertebral disc is weak, the application of such a force to the proximal end of suture  30  presents the possibility of pulling proximal anchor  25  through the annulus. Therefore, in order to eliminate the possibility of this occurrence, it may be desirable to utilize a tensioner  375  ( FIGS. 39-41 ) to hold the annulus in place while applying proximal tension to suture  30 . 
         [0118]    More particularly, a suture retriever  380 , having a loop  385  at its distal end, is advanced through a lumen  390  of tensioner  375  ( FIG. 39 ). The proximal end of suture  30  is fed through loop  385 , which is then pulled proximally through the tensioner so as to draw suture  30  through the tensioner ( FIG. 40 ). The feet  395  of tensioner  375  are then placed against the annulus adjacent to where suture  30  exits the annulus, and suture  30  is then pulled proximally, whereby to tension the suture and set it in position. As this occurs, feet  395  of tensioner  375  prevent the annulus from bowing outward, which could enable proximal anchor  25  to pass through the annulus. 
         [0119]    Alternatively, and looking now at  FIGS. 41A and 41B , a tensioner  400  may be provided. Tensioner  400  generally comprises a shaft  405  having a distal end  410  and a proximal end  415 . Distal end  410  terminates in a foot  420 . A ramped suture pathway  425  extends through distal end  410  of shaft  405  and through foot  420 . Proximal end  415  of shaft  405  is mounted to a handle  430 . A cutter tube  435  is slidably mounted on shaft  405 . Cutter tube  435  has a sharpened distal rim  440 . 
         [0120]    In use, when suture  30  is to be tensioned, the proximal end  190  of suture  30  is fed through ramped suture pathway  425 , foot  420  is placed against the annulus adjacent to where suture  30  exits the annulus, and then suture  30  is tensioned, with foot  420  of the tensioner preventing the annulus from bowing outward. Thereafter, excess suture may be cut away by moving cutter tube  435  distally along shaft  405  until its sharpened distal rim  440  engages and trims away excess suture. 
       Further Applications of the Novel System 
       [0121]    In the foregoing description, system  5  is discussed in the context of closing a fissure in the annulus of an intervertebral disc. However, it should be appreciated that system  5  may also be used to effect other anatomical repairs and/or fixations. 
         [0122]    By way of example but not limitation, the present invention may be used to hold two pieces of soft tissue in apposition to one another to effect a repair (e.g., so as to close an incision in the skin). See, for example,  FIG. 42 , where distal anchor  20  is shown disposed within the interior of one piece of soft tissue and proximal anchor  25  is shown disposed within the interior of another piece of soft tissue; and  FIG. 43 , where distal anchor  20  is shown disposed against an outer surface of one piece of soft tissue and proximal anchor  25  is shown disposed against an outer surface of another piece of soft tissue. Or the present invention may be used to hold two pieces of cartilage in apposition to one another to effect a repair (e.g., so as to close a tear in meniscal cartilage). See, for example,  FIG. 44 , where distal anchor  20  is shown disposed within the interior of one section of meniscal cartilage and proximal anchor  25  is shown disposed within the interior of another section of the same meniscal cartilage; and  FIGS. 45 and 46 , where distal anchor  20  is shown disposed against an outer surface of one section of meniscal cartilage and proximal anchor  25  is shown disposed against an outer surface of another section of the same meniscal cartilage. Or the present invention may be used to hold two pieces of bone in apposition to one another so as to effect a repair (e.g., so as to fuse together bone). See  FIG. 47 . 
         [0123]    By way of further example but not limitation, the present invention may be used to hold a piece of soft tissue in apposition to bone to effect a repair (e.g., so as to attach soft tissue to bone). See, for example,  FIG. 48 . Or the present invention may be used to hold a piece of cartilage in apposition to bone to effect a repair (e.g., so as to attach labrum to bone or to attach meniscal cartilage to bone). See  FIG. 49 . 
         [0124]    By way of further example but not limitation, the present invention may be used to hold a prosthesis in apposition to soft tissue or bone, or to hold soft tissue or bone in apposition to a prosthesis, and/or to hold any first object in apposition to any second object. 
         [0125]    It is also possible to use just distal anchor  20  and suture  30  to effect anatomical repairs and/or fixations, with proximal anchor  25  being omitted altogether. See, for example,  FIG. 50 , where a knot is used to hold soft tissue to a bone receiving distal anchor  20 , and  FIG. 51 , where a knot is used to hold a labrum to an acetabular rim receiving distal anchor  20 . If desired, multiple suture strands may be attached to the large ball (or knot)  185  which is positioned distal to distal anchor  20 , which can facilitate repair and/or fixation procedures. 
         [0126]    It is also possible to use proximal anchor  25  and suture  30  with an anchor other than distal anchor  20  to effect anatomical repairs and/or fixations. By way of example but not limitation, proximal anchor  25  and suture  30  may be used in conjunction with a conventional bone anchor (e.g., a conventional screw-type bone anchor or by a conventional barb-type bone anchor), with the conventional bone anchor replacing the aforementioned distal anchor  20  of the present invention. 
         [0127]    The following is a list of just some of the indications in which the present invention may be used:
       Foot/Ankle
           Hallux Valgus Repair   Hallux Varus Repair   Lisframe Repair   Correction Of The Intermediate Tarsal Angle   Brostrum Repair   Achilles Tendon Repair/Reconstruction   Medial Capsuloraphy Hallus Valgus   Lateral Stabilization   Medial Stabilization   Great Toe Tendon Repair   Mid- And Forefoot Tendon Reconstruction   
           Hand/Wrist
           CMC—Thumb Instability   CMC—Ligament Reconstruction   Ulnar—Collateral Ligament Repair   Scaphonlunate Repair   TFCC   Flexor Tendon Repair   
           Plastics/Maxillofacial
           Brow Lift   Face/Forehead Lift   Breast Lift   Breast Reconstruction   Crows Feet Repair   Blepharoplasty   
           Hip
           Hip Labrum Repair   
           Shoulder
           Rotator Cuff Repair   Partial Rotator Cuff Repair   Instability Repair (SLAP, Bankhart)   Capsular Shift   Capsular Plication   Tendon Transfers For Arthroplasty   Reverse Shoulder Arthroplasty Soft Tissue   
           Management
           Acromio-Clavicular Separation   Deltoid Repair   Biceps Tenodesis   
           Knee
           Meniscus Repair   Medial Collateral Ligament Repair   Lateral Collateral Ligament Repair   
           Elbow
           Distal Biceps Repair   Medial And Lateral Repairs   Tennis Elbow Repair   
               
 
       Use in Anchoring Sensory Nerve Stimulator (SNS) Leads 
       [0176]    As noted above, novel system  5  may be used to close a fissure in the annulus of an intervertebral disc, and/or to effect other anatomical repairs and/or other anatomical fixations. 
         [0177]    In one preferred form of the invention, novel system  5  may be used in a novel approach to anchor sensory nerve stimulator (SNS) leads. More particularly, in sensory nerve stimulation therapy, electrical leads are positioned adjacent to nerves and used to deliver electrical stimulation to those nerves so as to provide pain relief to a patient. In one significant application of nerve stimulation therapy, sensory nerve stimulator (SNS) leads are disposed adjacent to nerves in the spinal column, whereby to deliver electrical stimulation to those nerves and provide pain relief to the patient. See, for example,  FIG. 52 , which shows an SNS lead disposed adjacent to a nerve in the spinal column. 
         [0178]    In practice, it has been found extremely difficult to reliably anchor an SNS lead adjacent to a nerve in the spinal column. This is due to, among other things, the highly complex and varying anatomy of the spinal column, the need to fabricate the SNS lead with an atraumatic configuration, and the need to ensure that the SNS lead is reliably fixed in position. These factors, and others, combine to make it extremely difficult to reliably anchor an SNS lead adjacent to a specific nerve in the spinal column. 
         [0179]    Novel system  5  provides a new and improved approach for stabilizing an SNS lead adjacent to a nerve in the spinal column, by anchoring the SNS lead to one mass of material using the distal anchor of system  5  and by anchoring the SNS lead to another mass of material using the proximal anchor of system  5 , with the intervening suture securing the SNS lead reliably in position. Among other things, novel system  5  comprises a distal anchor  20  which is deployable, using a minimally-invasive approach, against the exterior of a hard or soft object (e.g., a bone, soft tissue, a hard prosthesis, a soft prosthesis, etc.), or within the interior of a hard or soft object (e.g., a bone, soft tissue, a hard prosthesis, a soft prosthesis, etc.), thereby providing a wide range of objects to which the distal anchor may be secured. Novel system  5  also comprises a proximal anchor  25  which is deployable, using a minimally-invasive approach, against the exterior of a hard or soft object (e.g., a bone, soft tissue, a hard prosthesis, a soft prosthesis, etc.), or within the interior of a soft object (e.g., soft tissue, a soft prosthesis, etc.), thereby providing a wide range of objects to which the distal anchor may be secured. And novel system  5  comprises a connecting suture  30  which may be used to atraumatically, but reliably, secure an SNS lead in position. 
         [0180]    Note that for the purposes of the present invention, the term “bone” is intended to include any bone or bone-like structure including, but not limited to, a vertebral body, a pedicle, a transverse process, a facet structure, a lamina, a spinous process, etc. Note also that for the purposes of the present invention, the term “soft tissue” is intended to include any relatively “soft” structure including, but not limited to, an intervertebral disc, a muscle, a ligament, a tendon, etc. 
         [0181]    See, for example,  FIG. 53 , which shows an SNS lead L adjacent to one mass of material M 1  for receiving distal anchor  20  of system  5 , and adjacent to another mass of material M 2  for anchoring proximal anchor  25  of system  5 .  FIG. 54  shows distal anchor  20  deployed against the exterior of a hard or soft mass of material M 1  (e.g., a bone, soft tissue, a hard prosthesis, a soft prosthesis, etc).  FIG. 55  shows distal anchor  20  deployed within the interior of a hard or soft mass of material M 1  (e.g., a bone, soft tissue, a hard prosthesis, a soft prosthesis, etc.).  FIG. 56  shows proximal anchor  25  deployed against the exterior of a hard or soft mass of material M 2  (e.g., a bone, soft tissue, a hard prosthesis, a soft prosthesis, etc).  FIG. 57  shows proximal anchor  25  deployed within the interior of a soft mass of material M 2  (e.g., soft tissue, a soft prosthesis, etc.). 
         [0182]    Thus, with the present invention, distal anchor  20  may be deployed through, or deployed within, any appropriate anatomical or prosthetic structure, and proximal anchor  25  may be deployed through, or deployed within, any appropriate anatomical or prosthetic structure, whereby to enable suture  30  to secure SNS lead L in the desired position within the patient&#39;s anatomy. 
         [0183]    As seen in  FIG. 58 , suture  30  may simply extend over SNS lead L, holding the SNS lead against underlying tissue. Alternatively, as shown in  FIG. 59 , suture  30  may be wrapped around SNS lead L. Where suture  30  is wrapped around the SNS lead, it may be possible to support the SNS lead in position even in the absence of underlying tissue, since suture  30  can be used to suspend SNS lead L over a gap in the tissue. Furthermore, if desired, SNS lead L may include an associated mount, e.g., in the form of a web W extending laterally about the SNS lead, and distal anchor  20  and proximal anchor  25  may be advanced through web W prior to deployment through or into a mass of material (e.g., M 1  or M 2 ), in the manner shown in  FIGS. 61 and 62 . 
         [0184]      FIGS. 63-70  show a variety of ways in which system  5  may be used to secure SNS lead L to adjacent structures. 
       Proximal Anchor Comprising Flexible Finger 
       [0185]    As noted above, novel system  5  may be used to close a fissure in the annulus of an intervertebral disc, and/or to effect other anatomical repairs and/or other anatomical fixations, including anchoring sensory nerve stimulator (SNS) leads. 
         [0186]    In another preferred form of the present invention, novel system  5  utilizes the aforementioned distal anchor  20  and the aforementioned suture  30  (and also the aforementioned inserter  15 ), but substitutes an alternative proximal anchor  25 A ( FIGS. 71 and 72 ) for the aforementioned proximal anchor  25 . 
         [0187]    More particularly, in this form of the invention, proximal anchor  25 A comprises a generally cylindrical body  90 A having a distal end  95 A, a proximal end  100 A and a generally circular side wall  105 A. Distal end  95 A terminates in a distal surface  110 A. Proximal end  100 A terminates in a proximal surface  120 A. A vertical bore  126 A passes completely through proximal anchor  25 A. Vertical bore  126 A is sized to slidably receive suture  30  therein. A recess  131 A passes part way through proximal anchor  25 A. A U-shaped slot  136 A passes part way through proximal anchor  25 A. Recess  131 A and U-shaped slot  136 A together define a flexible finger  141 A. In this form of the invention, a gap  142 A is formed between the inner tip  143 A of flexible finger  141 A and the edge  144 A formed at the convergence of recess  131 A and U-shaped slot  136 A. Preferably gap  142 A is sized so as to be approximately 50% of the width of suture  30  when flexible finger  141 A is in its relaxed, unbiased condition (i.e., in the position shown in  FIGS. 71 and 72 ) and when suture  30  is in its normal, uncompressed condition. A bottom horizontal slot  151 A extends between vertical bore  126 A and recess  131 A. Bottom horizontal slot  151 A may be stepped, comprising a wider outer portion  156 A and a narrower inner portion  161 A. If desired, wider outer portion  156 A may be sized to slidably receive suture  30  therein so as to help keep proximal anchor  25 A and suture  30  from binding when they are disposed within the aforementioned inserter  15 , but narrower portion  161 A may be sized to snugly receive suture  30  therein whereby to provide a light hold on suture  30  when suture  30  is disposed therein. 
         [0188]    As seen in  FIGS. 71 and 72 , suture  30  is passed through proximal anchor  25 A so that suture  30  extends down vertical bore  126 A, through wider outer portion  156 A of bottom horizontal slot  151 A, up through recess  131 A and out U-shaped slot  136 A. Note that inasmuch as suture  30  has a diameter which is approximately twice the size of gap  142 A formed between inner tip  143 A of flexible finger  141 A and edge  144 A of proximal anchor  25 A, flexible finger  141 A will normally bear against the suture disposed in gap  142 A. In this condition, the presence of the “oversized” suture  30  in the “undersized” gap  142 A will cause flexible finger  141 A to be flexed upwardly (from the angle of view of  FIGS. 71 and 72 ) so as to accommodate suture  30 , with inner tip  143 A of flexible finger  141 A capturing the suture against edge  144 A of proximal anchor  25 A. Note that some compression of suture  30  may occur in this condition. 
         [0189]    In addition to the foregoing, it should be appreciated that suture  30  follows a non-linear path through proximal anchor  25 A, and this non-linear path creates impedance to the passage of suture  30  through proximal anchor  25 A. 
         [0190]    In use, after the aforementioned distal anchor  20  has been deployed at the surgical site (preferably using the aforementioned inserter  15 ), proximal anchor  25 A is also deployed at the surgical site (again, preferably using the aforementioned inserter  15 ), and then suture  30  is set by pulling proximally on suture  30 . As suture  30  is pulled proximally, flexible finger  141 A flexes away from the body of proximal anchor  25 A, thereby allowing suture  30  to slide through recess  131 A and U-shaped slot  136 A (as well as through vertical bore  126 A and wider outer portion  156 A of bottom horizontal slot  151 A). When the slack in suture  30  has been taken up, and suture  30  is thereafter tensioned further, where bottom horizontal slot  151 A comprises a narrower portion  161 A, suture  30  is pulled from wider outer portion  156 A of bottom horizontal slot  151 A into narrower portion  161 A of bottom horizontal slot  151 A so that suture  30  is snugly received therein, such that proximal anchor  25 A provides a light hold on suture  30 . When tension on the free end of suture  30  is thereafter relaxed, flexible finger  141 A flexes back toward the body of proximal anchor  25 A, whereby to lock suture  30  to proximal anchor  25 A (i.e., with inner tip  143 A of flexible finger  141 A capturing the suture against edge  144 A of proximal anchor  25 A). In addition, inasmuch as suture  30  follows a non-linear path through proximal anchor  25 A, the non-linear path creates impedance to the passage of suture  30  through proximal anchor  25 A. In this way, suture  30  is secured to proximal anchor  25 A. Thereafter, a half-hitch may be formed in suture  30  on the proximal side of proximal anchor  25 A so as to further secure suture  30  to proximal anchor  25 A. 
       Single Anchor Fixation 
       [0191]    In another preferred form of the present invention, and looking now at  FIG. 73 , a single anchor system  500  may be used to secure an object (e.g., a sensory nerve stimulator “SNS” lead  505 ) to tissue (e.g., fascia  510 ). In this form of the invention, single anchor system  500  comprises a novel anchor  515  and a suture  520 . Single anchor system  500  is preferably deployed using the aforementioned inserter  15  (or another appropriate inserter). 
         [0192]    More particularly, anchor  515  comprises a generally cylindrical body  535  having a distal end  540 , a proximal end  545  and a generally circular side wall  550 . Distal end  540  terminates in a flat or somewhat inclined distal end surface  555  and a more inclined distal end surface  560 . Flat or somewhat inclined distal end surface  555  is sufficiently large so as to render distal end  540  of anchor  515  substantially blunt (but, where distal end surface  555  is somewhat inclined, also having a tapered lead-in). Inclined distal end surface  560  is pitched at an appropriate angle (e.g., 30 degrees, 45 degrees, etc.) so as to cause anchor  515  to turn during deployment (in the same manner that the aforementioned distal anchor  20  comprises a corresponding inclined distal surface  60  for causing turning), as will hereinafter be discussed. Proximal end  545  terminates in an inclined proximal end surface  565 . 
         [0193]    A vertical bore  570  passes through anchor  515 . Vertical bore  570  is sized to slidably receive suture  520  therein. A horizontal slot  575  extends between inclined distal end surface  560  and vertical bore  570 . Horizontal slot  575  is preferably also sized to slidably receive suture  520  therein, and helps keep anchor  515  and suture  520  from binding when they are disposed within the aforementioned inserter  15 . A pair of vertical bores  581 ,  583  are also disposed in anchor  515 , proximal to vertical bore  570 . Vertical bores  581 ,  583  are also sized to slidably receive suture  520  therein. A bottom horizontal slot  586  extends between vertical bore  581  and vertical bore  583 . 
         [0194]    Significantly, suture  520  follows a non-linear path through anchor  515 , and this non-linear path creates impedance to the passage of suture  520  through anchor  515 . 
         [0195]    If desired, bottom horizontal slot  586  may be stepped, comprising a wider outer portion  587  and a narrower inner portion  588 . Wider outer portion  587  may be sized to slidably receive suture  520  therein so as to help keep anchor  515  and suture  520  from binding when they are disposed within the aforementioned inserter  15 , but narrower portion  588  may be sized to snugly receive suture  520  therein, whereby to provide a light hold on suture  520  when suture  520  is disposed therein. 
         [0196]    As seen in  FIG. 73 , suture  520  has a distal end  591  terminating in a large ball (or knot)  592 , and a proximal segment  593 . Suture  520  is passed through anchor  515  so that so that large ball (or knot)  592  is disposed against the more inclined distal end surface  560 , and the suture extends along horizontal slot  575  of anchor  515 , up vertical bore  570  of anchor  515 , around the object (e.g., a sensory nerve stimulator “SNS” lead  505 ) which is to be secured to tissue (e.g., fascia  510 ), down vertical bore  581 , through bottom horizontal slot  586  (i.e., through wider outer portion  587  of bottom horizontal slot  586  where bottom horizontal slot is stepped), and up vertical bore  583 . 
         [0197]    In use, anchor  515  is deployed at the surgical site with suture  520  under tension so that anchor  515  is turned as it is ejected from the aforementioned inserter  15  (in the same manner that the aforementioned distal anchor  20  is turned as it is ejected from the aforementioned inserter  15 ), then suture  520  is tensioned by pulling proximally on proximal end  593  of suture  520 . As suture  520  is tensioned, sensory nerve stimulator “SNS” lead  505  is secured against fascia  510  (i.e., by virtue of anchor  515  being set in fascia  510  and by virtue of lead  505  being captured to anchor  515  via suture  520 ). Note that suture  520  will be held against slippage relative to anchor  515  by virtue of the fact that suture  520  follows a non-linear path through anchor  515 , and this non-linear path creates impedance to the passage of suture  520  through anchor  515 . When suture  520  is thereafter tensioned further, and where bottom horizontal slot  586  comprises a narrower portion  588 , suture  520  will be pulled from wider outer portion  587  of bottom horizontal slot  586  into narrower portion  588  of bottom horizontal slot  586  so that suture  520  is snugly received therein. This can provide an additional hold on suture  520 . Thereafter, a half-hitch  594  is formed in suture  520  on the proximal side of anchor  520  so as to secure the fixation. In this form of the invention, half hitch  594  will provide the primary fixation of suture  520  to anchor  515 , and the impedance created by the non-linear path of suture  520  through anchor  515  will provide significant additional fixation of suture  520 . Where bottom horizontal slot  586  comprises a narrower portion  588 , movement of suture  520  into narrower portion  588  can also provide a small additional holding force. 
       Single Anchor Fixation Utilizing Anchor Comprising Flexible Finger 
       [0198]    In another preferred form of the present invention, and looking now at  FIGS. 74-85 , a single anchor system  600  may be used (e.g., with the aforementioned inserter  15 ) to secure an object (e.g., a sensory nerve stimulator SNS lead  605 ) to tissue (e.g., fascia  610 ). In this form of the invention, single anchor system  600  comprises a novel anchor  615  and a suture  620 . Single anchor system  600  is preferably deployed using the aforementioned inserter  15  (or another appropriate inserter). 
         [0199]    More particularly, anchor  615  comprises a generally cylindrical body  625  having a distal end  630 , a proximal end  635  and a generally circular side wall  640 . Distal end  630  terminates in a flat or somewhat inclined distal end surface  645  and a more inclined distal end surface  650 . Flat or somewhat inclined distal end surface  645  is sufficiently large so as to render distal end  630  of anchor  615  substantially blunt (but, where distal end surface  645  is somewhat inclined, also having a tapered lead-in). Inclined distal end surface  650  is pitched at an appropriate angle (e.g., 30 degrees, 45 degrees, etc.) so as to cause anchor  615  to turn during deployment (in the same manner that the aforementioned distal anchor  20  comprises a corresponding inclined distal surface  60  for causing turning), as will hereinafter be discussed. Proximal end  635  terminates in an inclined proximal end surface  655 . 
         [0200]    A vertical bore  660  passes completely through anchor  615 . Vertical bore  660  preferably intersects inclined distal end surface  650  and is sized to slidably receive suture  620  therein. A recess  665  passes part way through anchor  615 . A U-shaped slot  670  passes part way through anchor  615 . Recess  665  and U-shaped slot  670  together define a flexible finger  675 . In this form of the invention, a gap  680  is formed between the inner tip  685  of flexible finger  675  and the edge  690  formed at the convergence of recess  665  and U-shaped slot  670 . Preferably gap  680  is sized so as to be approximately 50% of the width of suture  620  when flexible finger  675  is in its relaxed, unbiased condition (i.e., in the position shown in  FIGS. 78 and 83 ) and when suture  620  is in its normal, uncompressed condition. A bottom horizontal slot  695  extends between vertical bore  660  and recess  665 . Bottom horizontal slot  695  may be stepped, comprising a wider outer portion  700  and a narrower inner portion  705 . If desired, wider outer portion  700  may be sized to slidably receive suture  620  therein so as to help keep anchor  615  and suture  620  from binding when they are disposed within the aforementioned inserter  15 , but narrower portion  705  may be sized to snugly receive suture  620  therein whereby to provide a light hold on suture  620  when suture  620  is disposed therein. Alternatively, bottom horizontal slot  695  may comprise a slot of uniform width with a chamfer lead-in. 
         [0201]    As seen in  FIG. 83 , suture  620  has a distal end  710  terminating in a large ball or knot  715 , a proximal segment  720 , and an intermediate loop  725  which may be releasably secured to suture sled  280  of inserter  15 . Suture  620  is passed through anchor  615  so that large ball or knot  715  is disposed against the more inclined distal end surface  650 , and the suture extends into vertical bore  660 , loops around to form loop  725  (which is preferably releasably secured to suture sled  280  of inserter  15 ) and extends back down vertical bore  660 , through wider outer portion  700  of bottom horizontal slot  695  (if bottom horizontal slot  695  is stepped), up through recess  665  and out U-shaped slot  670 . Note that inasmuch as suture  620  has a diameter which is approximately twice the size of gap  680  formed between inner tip  685  of flexible finger  675  and edge  690  of anchor  615 , flexible finger  675  will normally bear against the suture disposed in gap  680 . In this condition, the presence of the “oversized” suture  620  in the “undersized” gap  680  will cause flexible finger  675  to be flexed upwardly (from the angle of view of  FIG. 83 ) so as to accommodate suture  620 , with inner tip  685  of flexible finger  675  capturing the suture against edge  690  of anchor  615 . Note that some compression of suture  620  may occur in this condition. 
         [0202]    In addition to the foregoing, it should be appreciated that suture  620  follows a non-linear path through anchor  615 , and this non-linear path creates impedance to the passage of suture  620  through anchor  615 . 
         [0203]    In use, anchor  615  is deployed at the surgical site with suture  620  under tension so that anchor  615  is turned as it is ejected from the aforementioned inserter  15  (in the same manner that the aforementioned distal anchor  20  is turned as it is ejected from the aforementioned inserter  15 ). In one preferred form of the invention, this is accomplished by releasably mounting loop  725  of suture  620  to suture sled  280  of inserter  15  during insertion of anchor  615 . Then loop  725  of suture  620  is released from suture sled  280 , SNS lead  605  is passed through loop  725 , and then suture  620  is tensioned by pulling proximally on proximal end  720  of suture  620 . As suture  620  is tensioned, flexible finger  675  flexes away from the body of anchor  615 , thereby allowing suture  620  to slide through recess  680  and U-shaped slot  670  (as well as through vertical bore  660  and wider outer portion  700  of bottom horizontal slot  695 ). When the slack in suture  620  has been taken up, whereby to pull SNS lead  605  tight against fascia  610 , and suture  620  is thereafter tensioned further, where bottom horizontal slot  695  comprises a narrower portion  705 , suture  620  is pulled from wider outer portion  700  of bottom horizontal slot  695  into narrower portion  705  of bottom horizontal slot  695  so that suture  620  is snugly received therein, such that anchor  615  provides a light hold on suture  620 . When tension on the free end of suture  620  is thereafter relaxed, flexible finger  675  flexes back toward the body of anchor  615 , whereby to lock suture  620  to anchor  615  (i.e., with inner tip  685  of flexible finger  675  capturing the suture against edge  690  of anchor  615 ). In addition, inasmuch as suture  620  follows a non-linear path through anchor  615 , the non-linear path creates impedance to the passage of suture  620  through anchor  615 . In this way, suture  620  is secured to anchor  615 . Thereafter, if desired, a half-hitch may be formed in suture  620  on the proximal side of anchor  615  so as to further secure suture  620  to anchor  615 , and hence secure SNS lead  605  to fascia  610 . 
         [0204]    In one preferred form of the invention, single anchor system  600  is configured so that its failure mode comprises slipping, not breaking (i.e., suture  620  will slip relative to anchor  615  before anchor  615  will break). 
         [0205]    And in one preferred form of the invention, anchor  615  comprises carbon fiber-reinforced PEEK (30%). 
         [0206]    Furthermore, if desired, anchor  615  may comprise a radiopaque material so that anchor  615  is visible under X-ray visualization. By way of example but not limitation, a radiopaque element may be incorporated in the body of anchor  615 . By way of further example but not limitation, a piece of Nitinol wire may be molded into anchor  615  so that the Nitinol wire extends through flexible finger  675  and into the adjoining body of anchor  615 —in this form of the invention, the Nitinol wire reinforces flexible finger  675  at the same time that it provides a radiopaque element in anchor  615 . 
       Inserter with Alternative Suture Sled 
       [0207]    In the foregoing disclosure, inserter  15  is characterized as having a suture sled  280  which is spring mounted to handle  200 . Suture sled  280  serves as a movable mount for securing the proximal portion of suture loop  320  (or suture loop  725 ) to handle  200 , such that suture sled  280  can slide along handle  200  as distal anchor  20  (or anchor  615 ) is advanced into a mass of material (e.g., an intervertebral disc, a bone, soft tissue, etc.), and then be stopped relative to handle  200  so that distal anchor  20  (or anchor  615 ) is driven against ball  185  (or ball  715 ), whereby to facilitate turning of distal anchor  20  (or anchor  615 ) within the mass of material. 
         [0208]    To this end, in the foregoing disclosure, suture sled  280  is characterized as being spring mounted to handle  200  so that suture sled  280  initially remains in a proximal position, whereby to hold suture  30  (or suture  620 ) under tension, until distal anchor  20  (or anchor  615 ) is driven distally by push rod  205  of inserter  15 , whereupon suture sled  280  is permitted to move distally, against the power of spring  285 , until distal anchor  20  (or anchor  615 ) is at the proper depth within the mass of material, whereupon distal movement of suture sled  280  is stopped, thereby stopping distal movement of ball  185  (or ball  715 ) and hence setting the depth of distal anchor  20  (or anchor  615 ). 
         [0209]    However, if desired, spring  285  may be omitted, and other means may be provided for releasably holding suture sled  280  in a proximal position until distal anchor  20  (or anchor  615 ) is driven distally by push rod  205 . By way of example but not limitation, suture sled  280  may be releasably held in a proximal position by means of a yielding stop finger, a ball-and-detent mechanism, or other releasable holding mechanism of the sort well known in the art. 
       Inserter with Impulse Driver 
       [0210]    In the foregoing disclosure, inserter  15  is characterized as having a push rod  205  which is moved distally by manually pressing on thumb button  310  (e.g., in the manner of manually pressing on the plunger of a syringe), whereby to drive distal anchor  20  (or anchor  615 ) distally. 
         [0211]    However, in some circumstances it can be desirable to drive distal anchor  20  (or anchor  615 ) with an impulse mechanism, so that an impulse of drive energy is applied to distal anchor  20  (or anchor  615 ). By way of example but not limitation, where distal anchor  20  (or anchor  615 ) is formed out of a material having limited strength (e.g., PEEK or PLLA), and where distal anchor  20  (or anchor  615 ) is to be set in a harder mass of material (e.g., bone), it can be helpful to set distal anchor  20  (or anchor  615 ) with an impulse mechanism. 
         [0212]    To this end, and looking now at  FIG. 86 , inserter  15  may be provided with a tension spring  800  which is secured to proximal end  240  of handle  200  and to thumb button  310  of push rod  205 . With such a construction, thumb button  310  may be pulled proximally, away from handle  200 , so that tension spring  800  is stretched and then, when impulse energy is to be applied to distal anchor  20  (or anchor  615 ) via push rod  205 , thumb button  310  is simply released, so that tension spring  800  applies impulse energy to thumb button  310  and hence causes push rod  205  to apply impulse energy to distal anchor  20  (or anchor  615 ). 
       MODIFICATIONS OF THE PREFERRED EMBODIMENTS 
       [0213]    It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.