Abstract:
The present invention provides a method for securing a suture to a suture retainer. The suture retainer includes first and second parts. The first part has a longitudinal axis and a recess having a longitudinal axis being generally parallel to the longitudinal axis of the first part. The second part is unattached to the first part and is configured and dimensioned to be received within the recess of the first part. The method further includes inserting a suture into the suture retainer with a portion of the suture positioned within the recess of the first part and the portion of the suture being generally parallel with the longitudinal axis of the recess. The suture is tensioned, and the second part of the suture retainer is moved into the recess of the first part to thereby clamp the portion of the suture between the first and second parts of the suture retainer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation of application Ser. No. 10/235,576 filed Sep. 5, 2002. The aforementioned application Ser No. 10/235,576 is itself a divisional of application Ser. No. 09/429,100 filed Oct. 28, 1999, now U.S. Pat. No. 6,231,592. The aforementioned application Ser. No. 09/429,100 is itself a divisional of application Ser. No. 08/905,084 filed Aug. 1, 1997, now U.S. Pat. No. 6,010,525. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to a new and improved method and apparatus for securing a suture against movement relative to body tissue by using a retainer to grip the suture.  
       BACKGROUND OF THE INVENTION  
       [0003]     Difficulty has been encountered in securing sutures against movement relative to body tissue. A knot may be tied in a suture to prevent loosening of the suture. However, the knot weakens a portion of the suture and reduces the overall force transmitting capability of the suture. In addition, a suture which is held by a knot applies force to a relatively small area of the body tissue and tends to cut or separate the body tissue. Many operations are conducted in very restricted space where the tying of a knot is difficult.  
         [0004]     Various methods of securing a suture against movement relative to body tissue are disclosed in U.S. Pat. Nos. 3,513,848; 4,662,068; 4,935,028; 5,306,280; and 5,593,425. Although these and other known methods of securing a suture have, to a greater or lesser extent, been successful, it is desirable to simplify the securing of a suture against movement relative to body tissue. It is also desirable to be certain that the suture applies a desired amount of force to the body tissue when the suture is secured. The overall force transmitting capability of the suture should be maximized without concentrating the force at a small area on the body tissue.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides a new and improved method and apparatus for use in securing a suture relative to body tissue. A suture retainer may be plastically deformed to grip the suture. The plastic deformation of the suture retainer may include pressing the material of the suture retainer against the suture by cold flowing material of the suture retainer. The plastic deformation of the material of the suture retainer may be performed while transmitting a predetermined force from the suture retainer to the body tissue.  
         [0006]     The strength of a connection between the suture retainer and the suture may be increased by forming bends in the suture before deforming the material of the suture retainer. As the suture retainer is moved along the suture toward the body tissue, the bends are moved along the suture with the suture retainer. The bends may be formed by wrapping the suture around a circular portion of the suture retainer, by moving the suture through one or more passages in the suture retainer, by bending the suture around a member, and/or by deflecting a portion of the suture retainer through which the suture extends.  
         [0007]     The suture retainer may be gripped with a tool which is moved along the suture to move the suture retainer toward the body tissue. The tool may be used to urge the suture retainer toward the body tissue with a predetermined minimum force. In addition, the tool may be used to plastically deform the material of the suture retainer when the suture retainer has been moved to a desired position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The foregoing and other features of the invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:  
         [0009]      FIG. 1  is a schematic illustration depicting the relationship of a suture retainer to a suture and body tissue prior to tightening of the suture;  
         [0010]      FIG. 2  is an enlarged sectional view illustrating the manner in which the suture is wrapped around the suture retainer of  FIG. 1  to form bends in the suture;  
         [0011]      FIG. 3  is a schematic illustration depicting the manner in which the suture retainer of  FIG. 2  is pressed against body tissue with a predetermined force and the manner in which a predetermined force is applied to an outer side surface of the suture retainer to plastically deform the suture retainer;  
         [0012]      FIG. 4  is an enlarged fragmentary schematic illustration of a portion of  FIG. 3  and depicting the manner in which the material of the suture retainer grips the suture;  
         [0013]      FIG. 5  is an enlarged fragmentary view of a portion of  FIG. 4  further illustrating the manner in which the material of the suture retainer grips the suture;  
         [0014]      FIG. 6  is a schematic pictorial illustration depicting the manner in which a suture is positioned relative to a base of a second embodiment of the suture retainer;  
         [0015]      FIG. 7  is a schematic illustration, taken along the line  7 - 7  of  FIG. 6 , depicting the manner in which a movable arm presses a portion of the suture into a groove formed in the base of the suture retainer to form bends in the suture;  
         [0016]      FIG. 8  is a schematic illustration depicting the manner in which force is applied against the suture retainer of  FIGS. 6 and 7  to plastically deform the suture retainer;  
         [0017]      FIG. 9  is a schematic illustration depicting the manner in which a suture is wrapped around another embodiment of the suture retainer to form bends in the suture;  
         [0018]      FIG. 10  is an enlarged fragmentary sectional view, taken generally along the line  10 - 10  of  FIG. 9 , illustrating the manner in which the suture is disposed in a groove in the suture retainer;  
         [0019]      FIG. 11  is a fragmentary sectional view, generally similar to  FIG. 10 , illustrating an alternative configuration for the groove in the suture retainer of  FIG. 9 ;  
         [0020]      FIG. 12  is a schematic illustration depicting the manner in which force is applied against the suture retainer of  FIG. 9  to plastically deform the suture retainer and grip the suture;  
         [0021]      FIG. 13  is a schematic illustration depicting another embodiment of the suture retainer and the manner in which sections of a suture are wrapped in opposite directions to form bends in the suture;  
         [0022]      FIG. 14  is a sectional view, taken generally along the line  14 - 14  of  FIG. 13 , illustrating the manner in which the suture is disposed in a groove in the suture retainer;  
         [0023]      FIG. 15  is an enlarged fragmentary schematic illustration of a portion of  FIG. 13 , further illustrating the manner in which the suture is disposed in grooves formed in the suture retainer;  
         [0024]      FIG. 16  is a fragmentary schematic sectional illustration of the manner in which the grooves and sections of the suture of  FIG. 15  cross;  
         [0025]      FIG. 17  is a schematic sectional view illustrating the manner in which a suture is wrapped around a roller in another embodiment of the suture retainer;  
         [0026]      FIG. 18  is a schematic illustration depicting the manner in which the suture retainer of  FIG. 17  is urged toward body tissue and the manner in which force is applied against the suture retainer to plastically deform the suture retainer;  
         [0027]      FIG. 19  is a fragmentary schematic illustration, generally similar to  FIG. 17 , depicting an alternative manner of wrapping the suture around the roller;  
         [0028]      FIG. 20  is a fragmentary schematic illustration of another embodiment of the suture retainer in which a housing encloses a plurality of cylinders around which the suture is wrapped;  
         [0029]      FIG. 21  is a schematic illustration depicting the manner in which the suture zig-zags through passages in another embodiment of the suture retainer;  
         [0030]      FIG. 22  is a schematic sectional view, taken generally along the line  22 - 22  of  FIG. 21 , further illustrating the manner in which the suture extends through the suture retainer;  
         [0031]      FIG. 23  is a schematic sectional view depicting the manner in which the suture zig-zags through passages in another embodiment of the suture retainer;  
         [0032]      FIG. 24  is a schematic sectional view illustrating the manner in which turns of a suture are wrapped in looped around another embodiment of the suture retainer;  
         [0033]      FIG. 25  is a schematic sectional view illustrating the manner in which turns of a suture are wrapped in looped around another embodiment of the suture retainer;  
         [0034]      FIG. 26  is a schematic sectional view illustrating the manner in which a two-section embodiment of the suture retainer is positioned relative to body tissue prior to engagement of the two sections of the suture retainer;  
         [0035]      FIG. 27  is a pictorial illustration of an inner or lower section of the suture retainer of  FIG. 26 ;  
         [0036]      FIG. 28  is a pictorial illustration of an outer or upper section of the suture retainer of  FIG. 26 ;  
         [0037]      FIG. 29  is a schematic sectional view of another two-section embodiment of the suture retainer prior to engagement of the two sections of the suture retainer;  
         [0038]      FIG. 30  is a schematic illustration of another two-section embodiment of the suture retainer;  
         [0039]      FIG. 31  is a pictorial illustration of an inner member used in the suture retainer of  FIG. 30 ;  
         [0040]      FIG. 32  is a schematic sectional illustration depicting the manner in which another embodiment of the suture retainer is pressed against a large area on body tissue with a predetermined force;  
         [0041]      FIG. 33  is a schematic view of the suture retainer of  FIG. 32  after the suture retainer has been plastically deformed to grip the suture;  
         [0042]      FIG. 34  is a schematic illustration depicting the manner in which another embodiment of the suture retainer is pressed against body tissue and the manner in which force is applied against the suture retainer to effect plastic deformation of the suture retainer;  
         [0043]      FIG. 35  is a schematic illustration of a tool which may be used to press the suture retainer of  FIG. 13  against body tissue and to plastically deform the material of the suture retainer; and  
         [0044]      FIG. 36  is a schematic illustration of another embodiment of a tool which may be used to press a suture retainer against body tissue and to plastically deform the material of the suture retainer. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
     Embodiment of FIGS.  1 - 5   
       [0045]     A suture retainer  50  ( FIG. 1 ) is utilized to secure a known suture  52  against movement relative to body tissue  54 . The suture  52  extends through an outer layer  56  and an inner layer  58  of the body tissue. The suture  52  has been illustrated schematically in  FIG. 1  as extending through passages  60  and  62  in the outer and inner layers  56  and  58  of body tissue  54 . However, the suture  52  could be sewn through the body tissue without forming the passages  60  and  62  in the body tissue.  
         [0046]     Although the suture  52  has been shown in  FIG. 1  in association with soft body tissue, it is contemplated that the suture  52  could be associated with hard body tissue. It is also contemplated that the suture  52  could extend through a suture anchor in a manner similar to that disclosed in U.S. Pat. Nos. 5,584,862; 5,549,631; and/or 5,527,343.  
         [0047]     The suture  52  has a left section  66  and a right section  68 . The left and right sections  66  and  68  of the suture  62  extend through the suture retainer  50  ( FIG. 2 ). If desired, the suture  52  could be integrally formed as one piece with the suture retainer  50 . If this was done, an end of one of the sections  66  or  68  of the suture  52  would be connected with the suture retainer  50 .  
         [0048]     Although the sections  66  and  68  of the suture  52  could extend straight through the suture retainer  50 , it is preferred to form a plurality of bends in the suture  52 . In the illustrated embodiment of the invention, two bends  72  and  74  ( FIG. 2 ) are formed in the left section  66  of the suture  52 . Similarly, two bends  76  and  78  are formed in the right section  66  of the suture  52 . If desired, a greater or lesser number of bends could be formed in each of the sections  66  and  68  of the suture  52 .  
         [0049]     The bends  72  and  74  ( FIG. 2 ) are formed in the left section  66  of the suture  52  by wrapping a turn  82  in the left section of the suture around a portion of the suture retainer  50 . Similarly, the bends  76  and  78  are formed in the right section  68  of the suture  52  by wrapping a turn  84  in the right section of the suture around a portion of the suture retainer  50 . A single loop  86  is formed in the left section  66  of the suture  52  around a portion of the suture retainer. Similarly, a single loop  88  is formed in the right section  68  of the suture  52  around a portion of the suture retainer  50 . A greater or lesser number of loops could be provided in the left and right sections  66  and  68  of the suture  52  if desired.  
         [0050]     The suture retainer  50  has a spherical configuration. A cylindrical passage  92  extends through the center of the spherical suture retainer  50 . If desired, the suture retainer  50  could have a different configuration. For example, the suture retainer  50  could have an oval or elliptical configuration. Although the passage  92  has a linear central axis, the passage could have a nonlinear central axis. If desired, a plurality of passages, having the same or different configurations, could be provided in the suture retainer  50 .  
         [0051]     The left and right sections  66  and  68  of the suture  52  extend through the passage  92 . In addition, the left and right sections  66  and  68  of the suture  52  extend around a spherical outer side surface  94  of the suture retainer  50 . Thus, the loop  86  in the left section  66  of the suture  52  extends around a left (as viewed in  FIG. 2 ) hemispherical portion of the suture retainer  50 . Similarly, the loop  88  extends around a right hemispherical portion of the suture retainer  50 .  
         [0052]     In the illustrated embodiment of the suture retainer  50 , the left and right sections  66  and  68  of the suture  52  engage the smooth spherical outer side surface  94  of the suture retainer  50 . However, it is contemplated that grooves could be provided in the outside of the suture retainer  50  to receive the turns  82  and  84  of the left and right sections  66  and  68  of the suture  52 . Alternatively, projections could extend from the spherical outer side surface  94  of the suture retainer  50  to engage the suture  52 .  
         [0053]     After the suture  52  has been inserted through the suture retainer  50 , in the manner illustrated schematically in  FIG. 2 , the suture retainer  50  is moved along the left and right sections  66  and  68  of the suture toward the body tissue  54  ( FIG. 1 ). To move the suture retainer  50  along the left and right sections  66  and  68  of the suture  52 , the left and right sections  66  and  68  of the suture are pulled upward (as viewed in  FIGS. 1 and 2 ) to tension the sections of the suture. A downward (as viewed in  FIG. 1 ) force is then applied against the suture retainer  50 . This downward force causes the suture retainer  50  to slide in a downward direction along the suture  52  toward an upper side surface  98  of the body tissue  54  ( FIG. 1 ).  
         [0054]     As the suture retainer  50  slides downward along the left and right sections  66  and  68  of the suture  52 , force is applied against the left section  66  of the suture  52  at the bend  74 . This force causes loop  86  in the left section  66  of the suture  52  to move downward (as viewed in  FIG. 2 ) along the left section of the suture. At the same time, force is applied against the right section  68  of the suture  52  at the bend  78 . This force causes the loop  88  in the right section  68  of the suture  52  to move downward along the right section of the suture.  
         [0055]     The suture retainer  50  is formed as one piece of a polymeric material having a relatively low coefficient of friction. Therefore, the two sections  66  and  68  of the suture  52  can readily slide along the outer side surface  94  and through the passage  92  in the suture retainer  50  as the suture retainer is moved downward toward the upper side surface  98  ( FIG. 1 ) of the body tissue  54 .  
         [0056]     While a predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 , the suture retainer  50  is pressed against the upper side surface  98  of the body tissue  54  ( FIG. 3 ). This results in a connector section  102  ( FIG. 1 ) of the suture  52  being pulled tightly against the inner layer  58  of body tissue. In order to obtain a desired tension in the left and right sections  66  and  68  and connector section  102  of the suture  52 , the suture retainer  50  is pressed against the upper side surface  98  of the body tissue with a predetermined force, indicated schematically by an arrow  104  in the  FIG. 3 . The suture retainer  50  increases the surface area on the body tissue  54  against which force is applied.  
         [0057]     Thus, while pulling on upper end portions of the left and right sections  66  and  68  of the suture  52  with a predetermined force, the suture retainer  50  is slid downward (as viewed in  FIG. 1 ) along the left and right sections of the suture. The suture retainer  50  is pressed against the body tissue  54  with a predetermined force  104  ( FIG. 3 ) which is sufficient to obtain a desired tension in the left and right sections  66  and  68  and connector section  102  of the suture  52 . In this manner, a desired force, which has been preselected, is applied against the body tissue  54  by the suture  52  and suture retainer  50 .  
         [0058]     Although the suture retainer  50  applies force against a far greater surface area on the body tissue  54  than would be engaged by a know in the suture  52 , a force distribution member or button may be placed between the suture retainer and the upper surface  98  of the body tissue. A second force distribution member or button may be placed between the connector section  102  of the suture and a lower side surface  108  ( FIG. 1 ) of the body tissue  54 . If this is done, the main area of engagement of the suture  52  with the body tissue  54  would be at the passages  60  and  62 .  
         [0059]     In accordance with a feature of the present invention, once the suture retainer  50  has been moved along the suture  52  and is being pressed against the body tissue  54  with a predetermined force  104  ( FIG. 3 ), the suture retainer is plastically deformed to grip the left and right sections  66  and  68  of the suture. While the suture retainer  50  is being pressed against the body tissue  54  with the predetermined force  104  and the left and right sections  66  and  68  of the suture are being tensioned, a pair of force application members  112  and  114  are pressed against opposite sides of the suture retainer  50 . The force applied against the suture retainer  50  by the force application members  112  and  114  plastically deforms the material of the suture retainer.  
         [0060]     The plastic deformation of the suture retainer  50  is effective to cause cold flowing of material of the suture retainer. Force indicated by arrows  118  and  120  in  FIG. 3 , is applied against the suture retainer  50  by the force application members  112  and  114 . This force is effective to cause flowing of the material of the suture retainer  50  at a temperature below a transition temperature range for the material of the suture retainer. Although the illustrated force application members  112  and  114  have flat force transmitting surfaces, each of the force application members could have force transmitting surfaces with a configuration corresponding to the configuration of a portion of a sphere.  
         [0061]     The cold flowing of the material of the suture retainer  50  results in a collapsing of the passage  92  ( FIG. 2 ) and in flowing of the material of the suture retainer  50  around the sections  66  and  68  of the suture  52 . This enables the material of the suture retainer  50  to bond to and obtain a firm grip on the suture  52 . The cold flowing of the material of the suture retainer  50  occurs at a temperature which is below the transition temperature of the material forming the suture retainer.  
         [0062]     In the illustrated embodiment of the suture retainer  50 , the material of the suture retainer flows around and grips the portion of the suture which was disposed in the passage  92 . In addition, the force applied against the turns  82  and  84  by the force application members  112  and  114  is sufficient to embed the turns  82  and  84  of the suture  52  in the material of the suture retainer  50  to further grip the suture. If the turns  82  and  84  are disposed in grooves in the outside of the suture retainer, the material of the suture retainer would more firmly grip the portion of the suture  52  forming the turns  82  and  84 . If desired, grooves could be formed in the cylindrical side surface of the passage  92  to receive the sections  66  and  68  of the suture  52 .  
         [0063]     A transducer or load cell  114  ( FIG. 3 ) is connected with the force application member  112  to measure the amount of force, indicated by the arrows  118  and  120 , which is applied against the suture retainer  50 . A display unit  126  is connected with the load cell  124  and provides an output indicative of the force being applied against opposite sides of the suture retainer  50  by the force application members  112  and  114 . After a predetermined minimum force has been applied against the suture retainer  50  for a predetermined minimum time by the force application members  112  and  114 , an output from the display unit  126  activates an indicator  130  to indicate to a surgeon that the desired plastic deformation of the suture retainer  50  has occurred. The force application members  112  and  114  can then be withdrawn from the suture retainer  50 .  
         [0064]     During the time in which the force application members  112  and  114  are applying the clamping forces  118  and  120  against opposite sides of the suture retainer  50 , the suture retainer is pressed against the upper side surface  98  of the body tissue  54  with a predetermined force, indicated at  104  in  FIG. 3 . In addition, a predetermined tension is maintained in sections  66  and  68  of the suture  52  extending upward from the suture retainer  50 . Upon disengagement of the force application members  112  and  114  from the suture retainer  50 , the application of the downward (as viewed in  FIG. 3 ) force  104  against the suture retainer  50  is interrupted. The upward tensioning of the sections  66  and  68  of the suture  52  is also interrupted.  
         [0065]     The application of the clamping forces  118  and  120  against opposite sides of the suture retainer  50  causes cold flowing of the material of the suture retainer. As this occurs, the material of the suture retainer  50  moves between and extends around the portions of the left and right sections  66  and  68  of the suture  52  disposed in the passage  92  ( FIG. 2 ). Thus, a portion  134  ( FIGS. 2 and 4 ) and a portion  136  of the left section  66  of the suture  52  are fully enclosed by the material of the suture retainer  50 . A cold bonding of the material of the suture retainer  50  with the exterior surfaces of the portions  134 ,  136  of the left section  66  of the suture retainer securely interconnects the material of the suture retainer and the suture  52 .  
         [0066]     Similarly, the portions  138  and  140  of the right section  68  of the suture  52  disposed in the passage  92  ( FIG. 2 ) are surrounded by and bonded with the material of the suture retainer  50  ( FIG. 4 ). The manner in which the material of the suture retainer  50  extends completely around and is connected with the length or portion  138  of the right section  68  of the suture  52  is illustrated schematically in  FIG. 5 . It should be understood that the permanent deformation of the material of the suture retainer  50  occurs as a result of compression of the material of the suture retainer while the material is at a temperature close to the temperature of the body tissue  54 . This temperature is below the transition temperature for the material of the suture retainer  50 .  
         [0067]     Once the suture retainer  50  has been plastically deformed to securely grip the suture  52 , the suture may be knotted if desired. Thus, a knot may be formed between the portions of the sections  66  and  68  of the suture  52  which extend upward (as viewed in  FIGS. 1-3 ) from the retainer  50 . Such a knot would provide additional protection against the suture working loose under the influence of varying loads over an extended period of time. Since the suture retainer  50  is disposed between the knot and the body tissue  54 , the knot will not reduce the overall force transmitting capability of the suture  52 . However, it is believed that forming a knot in the sections  66  and  68  of the suture  52  adjacent to the upper end of the suture retainer  50  will not be necessary.  
         [0068]     The suture retainer  50  may be formed of many different materials. However, it is believed that it will be preferred to form the suture retainer  50  of a biodegradable polymer. One biodegradable polymer which may be utilized is polycaperlactone. Alternatively, the suture retainer  50  could be formed of polyethylene oxide terephthalate or polybutylene terephthalate. It is also contemplated that other biodegradable or bioerodible copolymers could be utilized if desired.  
         [0069]     Although it is preferred to form the suture retainer  50  of a biodegradable material, the suture retainer could be formed of a material which is not biodegradable. For example, the suture retainer could be formed of an acetyl resin, such as “Delrin” (trademark). Alternatively, the suture retainer  50  could be formed of a para-dimethylamino-benzenediazo sodium sulfonate, such as “Dexon” (trademark).  
         [0070]     It is preferred to effect the cold flowing of the material of the suture retainer  50  without the addition of heat. However, it is contemplated that the suture retainer  50  could be heated to a temperature which is somewhat above the temperature of the body tissue  54 . If desired, heat could be transmitted to the suture retainer  50  through the force application members  112  and  114  ( FIG. 3 ). Although the suture retainer  50  may be heated, the suture retainer would be maintained at a temperature below the transition temperature for the material of the suture retainer.  
         [0071]     In the illustrated embodiment of the invention, the suture  52  is separate from the suture retainer  50 . However, one of the sections  66  or  68  of the suture  52  could be fixedly connected with the suture retainer  50 . This could be accomplished with a suitable fastener or by forming the suture  52  integrally as one piece with the suture retainer. This would result in the suture retainer  50  sliding along only one of the sections  66  or  68  of the suture  52 .  
         [0072]     The suture  52  may be formed of material or synthetic materials. The suture  52  may be a monofilament or may be formed of a plurality of interconnected filaments. The suture  52  may be biodegradable or nonbiodegradable. It may be preferred to form the suture  52  of the same material as the suture retainer  50 . However, the suture  52  could be formed of a material which is different than the material of the suture retainer.  
         [0073]     The use of the suture retainer  50  eliminates the necessity of forming a knot in the suture  52 . By eliminating the formation of a knot in the suture  52 , the overall force transmitting capability of the suture is increased. In addition to increasing the overall force transmitting capability of the suture  52 , the suture retainer  50  increases the surface area on the body tissue  54  ( FIG. 1 ) against which force is applied by the suture. This tends to minimize any tendency for the suture  52  to cut or separate the body tissue.  
         [0074]     It is believed that it may be preferred to position the left and right sections  66  and  68  of the suture  52  relative to the body tissue  54  ( FIG. 1 ) before winding the two sections of the suture around the suture retainer  50 . However, one of the sections  66  or  68  of the suture  52  may be wound around the suture retainer  50  before the suture is positioned in the passages  60  and  62  in the body tissue  54 . For example, the left section  66  of the suture  52  may e wound around the suture retainer  52  to form the bends  72  and  74  and the loop  86  ( FIG. 2 ) while the suture is spaced from the body tissue  54 . The right section  68  of the suture is then inserted through the passages  60  and  62  ( FIG. 1 ) in the body tissue  54 . The right section  68  of the suture  52  is then wound around the suture retainer  50  to form the bends  76  and  78  and loop  88  ( FIG. 2 ).  
       Embodiment of FIGS.  6 - 8   
       [0075]     In the embodiment of the invention illustrated in  FIGS. 1-5 , complete loops  86  and  88  are formed in the sections  66  and  68  of the suture  52 . In the embodiment of the invention illustrated in  FIGS. 6-8 , partial loops are formed in each of the sections of the suture. Since the embodiment of the invention illustrated in  FIGS. 6-8  is similar to the embodiment of the invention illustrated in  FIGS. 1-5 , similar terminology will be utilized to identify similar components. It should be understood that one or more features of the embodiment of the invention illustrated in  FIGS. 1-5  may be used with the embodiment of the invention illustrated in  FIGS. 6-8 .  
         [0076]     A suture retainer  150  is utilized to secure a suture  52  against movement relative to body tissue. The suture  52  has sections  66  and  68  which engage body tissue in the same manner as previously described in conjunction with the embodiment of the invention illustrated in  FIGS. 1-5 . Although the suture  52  is illustrated in  FIG. 1  in association with soft body tissue, it is contemplated that the suture  52  could be utilized in association with hard body tissue and/or one or more suture anchors.  
         [0077]     The suture retainer  150  includes a rectangular base or body section  152  and a movable post or locking section  154 . The post or locking section  154  is integrally formed as one piece with the base  152 . The post or locking section is hingedly connected with the base  152  at a connection  156 . The post  154  is pivotal relative to the base at the connection  156  in the manner indicated schematically by the arrow  158  in  FIG. 6 .  
         [0078]     The base  152  has a central groove  162  which is aligned with the post  154 . The groove  162  has a rectangular cross sectional configuration. The groove  162  has a cross sectional area which is greater than the cross sectional area of the post  154 . In the illustrated embodiment of the suture retainer  150 , the post  154  and groove  162  both have a rectangular cross sectional configuration. However, the post and groove could have a different cross sectional configuration if desired. For example, the post  154  and groove  162  could have a semi-circular cross sectional configuration.  
         [0079]     The base  152  has a pair of flat rectangular upper (as viewed in  FIGS. 6 and 7 ) side surfaces  166  and  168 . The flat side surfaces  166  and  168  extend in opposite directions from the groove  162  and extend parallel to a flat rectangular bottom surface  170 . The suture retainer  150  is formed from a single piece of a biodegradable polymer, such as polycaperlactone. Of course, other biodegradable or bioerodible copolymers could be utilized to form the suture retainer  150 . It is contemplated that the suture retainer  150  may be formed of materials which are not biodegradable.  
         [0080]     When the suture retainer  150  is to be utilized to hold the sections  66  and  68  of the suture  52  against movement relative to body tissue, the post  154  is pivoted from its initial or extended position, shown in  FIG. 6 , to its engaged or locking position, shown in  FIG. 7 . As the post  154  is pivoted to the engaged position of  FIG. 7 , a flat side surface  174  of the post is pressed against the sections  66  and  68  of the suture to force the sections into the groove  162 . The post is effective to clamp or hold the sections  66  and  68  of the suture  52  against movement relative to the base  152  upon movement of the post to the engaged position shown in  FIG. 7 .  
         [0081]     Once the post  154  has been moved to the engaged position shown in  FIG. 7 , the base  152  is bent from the flat orientation of  FIGS. 6 and 7  to the folded orientation of  FIG. 8 . Once the base  152  has been folded, a pair of force application members  112  and  114  engage opposite sides of the bottom or outer surface  170  of the base. The force application members  112  and  114  are then pressed toward each other, in the manner indicated schematically by the arrows  118  and  120  in  FIG. 8 , to apply pressure against the suture retainer  150 .  
         [0082]     At this time, the suture retainer  150  is at a temperature below the transition temperature of the material forming the suture retainer. Thus, the suture retainer  150  is at a temperature which is approximately the same as the temperature of the body tissue relative to which the suture retainer  150  is being utilized to secure the suture  52 . The force applied against the suture retainer  150  by the force application members  112  and  114  plastically deforms the material of the suture retainer. This results in a cold flowing of the material of the suture retainer  150  under the influence of the force applied against the suture retainer by the force application members  112  and  114 .  
         [0083]     A transducer or load cell  124  measures the force  118  and  120  applied against the base  152  of the suture retainer  150 . The load cell  124  provides an output signal to a display unit  126 . The output signal provided by the transducer  124  corresponds to the magnitude of the force applied against opposite sides of the suture retainer  150  by the members  112  and  114 .  
         [0084]     After a predetermined minimum force has been applied against opposite sides of the suture retainer  150  for a sufficient period of time to effect a cold flowing of the material of the suture retainer, an output signal from the display unit  126  activates an indicator  130 . The output from the indicator  130  indicates to a surgeon and/or other medical personnel that the force has been applied against opposite sides of the suture retainer  150  by the force application members  112  and  114  for a period of time sufficient to cause cold flowing of the material of the suture retainer. The cold flowing of the material of the suture retainer  150  results in a secure interconnection between the material of the suture retainer  150  and the sections  66  and  68  of the suture  52 .  
         [0085]     In the embodiment of the invention illustrated in  FIGS. 6-8 , the suture  52  is separate from the suture retainer  150 . However, the suture  52  could be fixedly connected to or integrally formed as one piece with the suture retainer  150 . For example, the base  152  could be integrally formed with the section  66  of the suture  52  if desired.  
       Embodiment of FIGS.  9 - 12   
       [0086]     In the embodiment of the invention illustrated in  FIGS. 1-5 , the sections  66  and  68  of the suture  52  extend through a passage formed in a spherical suture retainer  50 . In the embodiment of the invention illustrated in  FIGS. 9-12 , the sections of the suture extend along a groove formed in the outside of a suture retainer. Since the embodiment of the invention illustrated in  FIGS. 9-12  is similar to the embodiment of the invention illustrated in  FIGS. 1-5 , similar terminology will be utilized to identify similar components. It should be understood that one or more features of the embodiments of the invention illustrated in  FIGS. 1-8  may be used with the embodiment of the invention illustrated in  FIGS. 9-12 .  
         [0087]     A suture retainer  180  ( FIG. 9 ) is utilized to secure a suture  52  against movement relative to body tissue  54 . Although the body tissue  54  is soft body tissue, it is contemplated that the suture retainer  180  could be utilized to secure the suture  52  against movement relative to hard body tissue, such as bone. The suture retainer  180  may be used either with or without a suture anchor.  
         [0088]     The suture retainer  180  has a cylindrical main section or body  184 . The body  184  has a cylindrical outer side surface  186 . Flat circular end surfaces  188  and  190  extend perpendicular to a longitudinal central axis of the cylindrical side surface  186 . In the illustrated embodiment of the suture retainer  180 , the body  184  is cylindrical and has a linear longitudinal central axis. If desired, the body  184  could be rectangular and/or have a nonlinear longitudinal central axis.  
         [0089]     A helical groove  194  is formed in the body  184 . The helical groove  194  has a constant pitch. Therefore, turns of the groove  194  are equally spaced. However, if desired, the pitch of the turns of the groove  194  could vary along the length of the body  184 .  
         [0090]     The helical groove  194  has a central axis which is coincident with the central axis of the body  184  and cylindrical outer side surface  186  of the suture retainer  180 . A radially inner portion of the helical groove  194  defines a right circular cylinder which is coaxial with the outer side surface  186  of the body  184 . However, the radially inner portion of the helical groove  194  could define a right circular cone or other configuration if desired.  
         [0091]     The left and right sections  66  and  68  of the suture  52  extend through the groove  194  and around body tissue  54 . It is believed that it will be advantageous to provide the helical groove  194  with retainers or bridge sections  198  and  200  which extend across the open ends of the helical groove. The bridge sections  198  and  200  are integrally formed as one piece with the body  184 . The bridge sections  198  and  200  prevent the sections  66  and  68  of the suture  52  from pulling out of the helical groove  194  during positioning of the suture retainer  180  in a human patient&#39;s body. However, the bridge sections  198  and  200  may be omitted if desired.  
         [0092]     The helical groove  194  has a generally U-shaped cross sectional configuration ( FIG. 10 ). Thus, the helical groove  194  has an open mouth or entrance  204 . A pair of side surfaces  206  and  208  slope radially inward and axially upward (as viewed in  FIGS. 9 and 10 ) from the entrance  204 . An arcuate bottom surface  210  of the groove  194  extends between the side surfaces  206  and  208 .  
         [0093]     The section  66  of the suture  52  is disposed in engagement with the bottom surface  210  of the helical groove  194 . The section  68  of the suture  52  is disposed in engagement with the section  66  of the suture ( FIG. 10 ). If desired, the size of the arcuate bottom surface  210  of the groove  194  could be increased to enable both sections  66  and  68  of the suture  52  to engage the bottom surface.  
         [0094]     The groove  194  may be provided with a configuration similar to the configuration shown in  FIG. 11 . Thus, in  FIG. 11 , the side surfaces  206  and  208  of the helical groove  194  extend inward from the open entrance  204  to an arcuate bottom surface  210  which forms a major portion of a circle. The bottom surface  210  of  FIG. 11  defines a recess  214  in which the two sections  66  and  68  of the suture are disposed. It is believed that the bridge sections  198  and  200  will probably be omitted with the embodiment of the groove  194  illustrated in  FIG. 11 .  
         [0095]     The cylindrical body  184  of the suture retainer  180  is molded from a single piece of a biodegradable polymer. For example, the body  184  of the suture retainer  180  may be molded from polycaperlactone. Alternatively, the body  184  of the suture retainer  180  could be molded of polyethylene oxide terephthalate or polybutylene terephthalate. Of course, the body  184  of the suture retainer  180  could be molded as one piece of other biodegradable or bioerodible copolymers if desired. Although it is preferred to form the body  184  of biodegradable materials, the body could be formed of materials which are not biodegradable. For example, the body  184  could be formed of “Delrin” (trademark).  
         [0096]     The left and right sections  66  and  68  ( FIG. 9 ) of the suture  52  are inserted into the helical groove  194  in the body  184  of the suture retainer  180 . At this time, the body  184  of the suture retainer  180  is spaced from the body tissue  54 . It is believed that insertion of the left and right sections  66  and  68  of the suture  52  into the helical groove  194  will be facilitated if the bridge sections  198  and  200  are omitted. However, if the bridge sections  198  and  200  are omitted, difficulty may be encountered in maintaining the sections  66  and  68  of the suture  52  in the helical groove  194 .  
         [0097]     As the left and right sections  66  and  68  of the suture  52  are inserted into the helical groove  194  ( FIG. 9 ), the sections of the suture are wrapped around the body  184  of the suture retainer  180 . As this occurs, a plurality of helical loops are formed in the left and right sections  66  and  68  of the suture  52 . Once the suture  52  has been inserted into the helical groove  194 , a plurality of circular turns are maintained in the left and right sections  66  and  68  of the suture  52  by the helical groove  194 . Therefore, a continuous series of smooth arcuate bends, which are free of stress inducing discontinuities, is maintained in the suture  52  by the helical groove  194 .  
         [0098]     After the suture  52  has been inserted into the helical groove  194 , the suture retainer  180  is moved along the suture toward the body tissue  54  ( FIG. 9 ). During this movement of the suture retainer  180  along the suture  52 , the left and right sections  66  and  68  of the suture are tensioned. The radially inward and axially upward sloping configuration of the helical groove  194  ( FIGS. 10 and 11 ) results in the left and right sections  66  and  68  of the suture being pulled toward the arcuate bottom surface  210  of the groove. This results in the body  184  of the suture retainer  180  maintaining the helical loops in the left and right sections  66  and  68  of the suture  52  as the suture retainer  180  moves toward the body tissue  54 .  
         [0099]     As the suture retainer  180  moves toward the body tissue  54  ( FIG. 9 ), the left and/or right sections  66  and  68  of the suture  52  slide along the arcuate bottom surface  210  ( FIG. 10 ) of the groove  194 . The groove  194  imparts a helical configuration to the portion of the suture  52  disposed in the groove. As the body  184  of the suture retainer  180  moves downward toward the body tissue  54 , the portion of the suture  52  having a helical configuration moves downward toward the body tissue.  
         [0100]     As the suture retainer  180  is slid along the tensioned sections  66  and  68  of the suture  52 , the tensioning force in the suture pulls the suture toward the bottom surface  210  of the helical groove  194 . The biodegradable copolymer forming the body  184  of the suture retainer  180  has a low coefficient of friction. This minimizes the force  220  required to move the suture retainer along the left and right sections  66  and  68  of the suture  52  toward the body tissue  54 .  
         [0101]     The suture retainer  180  is moved along the taut left and right sections  66  and  68  of the suture  52  until the leading end surface  190  of the body  184  of the suture retainer  180  engages the body tissue  54  ( FIG. 9 ). The force  220  is then increased to a predetermined magnitude while maintaining a predetermined tension in the left and right sections  66  and  68  of the suture  52 . This results in the suture  52  being pulled tightly around the body tissue and exerting a predetermined force against the body tissue.  
         [0102]     It is contemplated that the magnitude of the force  220  ( FIG. 9 ) with which the suture retainer  190  is pressed against the body tissue  54  will be measured to be certain that the force has a desired magnitude. The force  220  may be measured with a suitable transducer, such as a load cell or a force measuring device having a spring which is compressed to a predetermined extent by the application of the desired force against the body tissue  54 . Rather than engaging the body tissue  54  directly with the leading end surface  190  of the suture retainer  180 , a suitable force transmitting member, such a button, could be provided between the suture retainer and the body tissue.  
         [0103]     While the suture retainer  180  is being pressed against the body tissue  54  with the predetermined force  220  and the sections  66  and  68  of the suture  52  are being tensioned with a predetermined force, the left and right sections  66  and  68  of the suture  52  are gripped by plastically deforming the material of the suture retainer. To plastically deform the material of the suture retainer, a plurality of force application members  224 ,  226  and  228  ( FIG. 12 ) are pressed against the cylindrical outer side surface  186  of the suture retainer  180 . Since the outer side surface  186  of the suture retainer  180  has a cylindrical configuration, the force application members  224 ,  226  and  228  have an arcuate configuration and are formed as portions of a circle. However, the force application members  224 ,  226  and  228  could have the flat configuration of the force application members  112  and  114  of  FIG. 3 .  
         [0104]     The force application members  224 ,  226  and  228  are pressed against the outer side surface  186  of the suture retainer  180  with a predetermined force, indicated by the arrows  232  in  FIG. 12 . This force has a magnitude and is applied for a length of time sufficient to cause cold flowing of the material of the body  184  of the suture retainer  180 . The plastic deformation of the material of the body  194  of the suture retainer  180  results in the helical groove  194  being collapsed and the, material of the suture retainer being pressed against the left and right sections  66  and  68  of the suture  52 . The resulting cold bonding of the material of the suture retainer  180  with the left and right sections  66  and  68  of the suture  52  secures in the suture retainer against movement relative to the suture.  
         [0105]     The cold flowing of the material of the body  184  of the suture retainer  180  occurs with the body of the suture retainer at substantially the same temperature as the temperature of the body tissue  54  ( FIG. 9 ). Thus, the cold flowing of the material of the body  184  of the suture retainer  180  occurs at a temperature below the transition temperature of the material forming the body  184  of the suture retainer  180 . However, if desired, some heat may be added to the body  184  to facilitate plastic deformation of the body of the suture retainer  180 .  
         [0106]     The suture retainer  180  eliminates the necessity of forming a knot in the suture  52 . The formation of a knot in the suture  52  would cause a stress concentration in the suture and would decrease the overall force transmitting capability of the suture. By eliminating the knot, the overall force transmitting capability of the suture  52  is increased. However, if desired, a knot could be formed in the sections  66  and  68  of the suture  52  at a location above (as viewed in  FIG. 1 ) the suture retainer  180 . Since the suture retainer  180  would be disposed between this knot and the body tissue  54 , the knot would not decrease the overall force transmitting capability of the suture  52 .  
         [0107]     In the embodiment of the invention illustrated in  FIGS. 9-12 , a single helical groove  194  is formed in the body  184  of the suture retainer  180 . It is contemplated that a pair of spaced apart helical grooves could be formed in the body  184  of the suture retainer  180 . If this was done, the two helical grooves would be wrapped in the same direction around the body  184  of the suture retainer  180  and would be offset from each other by 180° about the circumference of the cylindrical body of the suture retainer. The left section  66  of the suture  52  would be disposed in one of the helical grooves and the right section  68  of the suture would be disposed in the other helical groove.  
         [0108]     By having a pair of spaced apart helical grooves in the body  184  of the suture retainer  180 , in the manner set forth in the preceding paragraph, the left and right sections  66  and  68  of the suture  52  would exit from the lower (as viewed in  FIG. 9  end of the suture retainer at diametrically opposite locations on the circular end surface  190 . This embodiment of the suture retainer  180  would have the advantage of having a relatively large area of engagement with the body tissue  54 . Thus, the tension in the suture would press the flat circular end surface  190  on the suture retainer against the body tissue.  
         [0109]     In the illustrated embodiment of the invention, the suture  52  is separate from the suture retainer  180 . However, if desired, the suture  52  could be fixedly connected with or integrally formed as one piece with the suture retainer. For example, the left section  66  of the suture  52  could be fixedly connected with the body  184  of the suture retainer  180  by a suitable fastener. If this was done, only the right section  68  of the suture  52  would be received in the groove  194 .  
       Embodiment of FIGS.  13 - 16   
       [0110]     In the embodiment of the invention illustrated in  FIGS. 9-12 , the left and right sections  66  and  68  of the suture  52  are wrapped in the same direction around the cylindrical body  184  of the suture retainer  180 . In the embodiment of the invention illustrated in  FIGS. 13-16 , the sections of the suture are wrapped in opposite directions around a conical body of a suture retainer. Since the embodiment of the invention illustrated in  FIGS. 13-16  is similar to the embodiment of the invention illustrated in  FIGS. 9-12 , similar terminology will be utilized to identify similar components. It should be understood that one or more features of the embodiments of the invention illustrated in  FIGS. 1-12  may be used with the embodiments of the invention illustrated in  FIGS. 13-16 .  
         [0111]     A suture  52  ( FIG. 13 ) has left and right sections  66  and  68  which are wrapped in opposite directions around a conical body  242  of a suture retainer  244 . Thus, as viewed from above, the left section  66  of the suture  52  is wrapped in a counterclockwise direction around the body  242  of the suture retainer  244 . The right section  68  of the suture  52  is wrapped in a clockwise direction around the body  242  of the suture retainer  244 .  
         [0112]     The left and right sections  66  and  68  of the suture  52  are wrapped for approximately 1½ turns around the body  242  of the suture retainer  244 . Therefore, the left section  66  of the suture  52  moves from the left side of the upper end (as viewed in  FIG. 13 ) of the body  242  of the suture retainer  244  to the right side of the lower end of the body of the suture retainer. Similarly, the right section  68  of the suture  52  moves from the upper right side of the body  242  of the suture retainer  244  to the lower left side of the body of the suture retainer.  
         [0113]     If the two sections  66  and  68  of the suture  52  were wrapped around the body  242  of the suture retainer  244  for complete turns, the sections of the suture would be on the same side of the body  242  at the top and bottom of the suture retainer. For example, if the suture  52  was wrapped two complete turns around the body  242 , the left section  66  of the suture  52  would be disposed at the left side of both the upper and lower ends of the body  242 . Similarly, the right section  68  of the suture  52  could be disposed at the right side of both the upper and lower ends of the body  242  of the suture retainer.  
         [0114]     The body  242  of the suture retainer  244  is formed as a portion of a right circular cone. The body  242  of the suture retainer  244  has an outer side surface  248  with an axially downward (as viewed in  FIG. 13 ) and radially inward tapering configuration. The conical body  242  of the suture retainer  244  has parallel circular end surfaces  252  and  254  which extend perpendicular to a longitudinal central axis of the conical body. The circular end surfaces  252  and  254  are disposed in a coaxial relationship. The upper end surface  252  has a larger diameter than the lower end surface  254 .  
         [0115]     A pair of helical grooves  258  and  260  ( FIGS. 13-16 ) are formed in the conical body  242 . The helical grooves  258  and  260  have a spiral configuration with a central axis which is coincident with the central axis of the conical body  242 . Thus, the diameter of the turns of the grooves  258  and  260  progressively decreases as the grooves extend downward (as viewed in  FIG. 13 ) from the upper end surface  252  to the lower end surface  254 . The helical grooves  258  and  260  have the same pitch.  
         [0116]     The helical grooves  258  and  260  are wrapped in opposite directions around the conical body  242  of the suture retainer  244 . Thus, as viewed from above, the helical groove  258  is wrapped in a counterclockwise direction around the body  242  of the suture retainer  244 . The helical groove  260  is wrapped in a clockwise direction around the body  242  of the suture retainer  244 .  
         [0117]     The helical grooves  258  and  260  are offset by 180°. Thus, the helical groove  258  beings at the upper left (as viewed in  FIG. 13 ) side of the body  242  and the helical groove  260  begins at the upper right side of the body  242 . The entrances to the helical grooves  258  and  260  are disposed at diametrically offset locations on the circular upper end surface  252  of the body  242 . The helical groove  258  ends at the lower right (as viewed in  FIG. 13 ) side of the body  242 . The helical groove  260  ends at the lower left side of the body  242 . The exits from the helical grooves  258  and  260  are disposed at diametrically offset locations on the circular lower end surface  254  of the body  242 . This results in the relatively large lower end surface  254  of the body  242  being disposed between the left and right sections  66  and  68  of the suture  52  and exposed to body tissue.  
         [0118]     The groove  258  has an axially upward and radially inward sloping configuration ( FIG. 14 ). The groove  258  has a helical open mouth or entrance  264 . The groove  258  has a pair of axially upward and radially inward sloping side surfaces  266  and  268 . The side surfaces  266  and  268  are interconnected by an arcuate bottom surface  270 . The groove  258  has the same depth and cross sectional configuration throughout the extent of the groove.  
         [0119]     Although only the groove  258  is illustrated in  FIG. 14 , it should be understood that the groove  260  has the same cross sectional configuration as the groove  258 . The two grooves  258  and  260  extend between the opposite end surfaces  252  and  254  of the conical body  242 . It is contemplated that the grooves  258  and  260  could have a different cross sectional configuration if desired. For example, the grooves  258  and  260  could have the cross sectional configuration shown in  FIG. 11  if desired.  
         [0120]     The grooves  258  and  260  intersect on opposite sides of the conical body  242  in the manner illustrated in  FIGS. 15 and 16 . At the intersections between the grooves  258  and  260 , the left and right sections  66  and  68  of the suture  52  overlap ( FIG. 16 ). The number of intersections of grooves  258  and  260  will vary as a direct function of the number of turns of the grooves  258  and  260  around the body  242 .  
         [0121]     Bridge sections  274  and  276  ( FIG. 13 ) are provided across opposite ends of the groove  258  to facilitate in retaining the suture section  66  in the groove. Similarly, bridge sections  278  and  280  are provided across opposite ends of the groove  260  to facilitate in retaining the suture section  68  in the groove  260 . If desired, the bridge sections  274 ,  276 ,  278  and  280  could be omitted.  
         [0122]     In addition to the conical body  242 , the suture retainer  244  includes a cylindrical sleeve  284  ( FIG. 13 ). The tubular sleeve  284  has a cylindrical outer side surface  286  and a conical inner side surface  288 . The inner and outer side surfaces  286  and  288  are disposed in coaxial relationship. The conical inner side surface  288  of the sleeve  284  tapers axially inward and downward (as viewed in  FIG. 13 ) at the same angle as does the conical outer side surface  248  of the body  242 .  
         [0123]     Although the conical inner side surface  288  of the sleeve  284  has been schematically illustrated in  FIG. 13  as having an inside diameter which is greater than the outside diameter of the conical body  242 , it is contemplated that the conical body  242  will have substantially the same diameter as the inner side surface  288  of the sleeve  284 . Therefore, when the circular end surface  252  on the conical body  242  is axially aligned with an annular end surface  292  on the sleeve  284  (as shown in  FIG. 13 ), the outer side surface  248  on the conical body  242  will be disposed in abutting engagement with the inner side surface  288  on the sleeve  286 . Of course, if the conical inner side surface  288  of the sleeve  284  has a larger diameter than the conical outer side surface  248  of the body  242 , axially downward (as viewed in  FIG. 13 ) movement of the conical body  242  relative to the sleeve  284  will result in abutting engagement between the inner side surface  288  of the sleeve and the outer side surface  248  of the conical body.  
         [0124]     The conical body  242  and the sleeve  284  are both formed of a biodegradable polymer, such as polycaperlactone. However, the conical body  242  and the sleeve  284  could be formed of polyethylene oxide terephthalate or polybutylene terephthalate if desired. Other biodegradable or bioerodible copolymers could be utilized if desired. It is contemplated that it may be desired to form the conical body  242  and sleeve  284  of a polymer which is not biodegradable. The conical body  242  and sleeve  284  could be formed of two different materials if desired.  
         [0125]     When the suture retainer  244  is to be positioned in a human patient&#39;s body, the left and right sections  66  and  68  of the suture are first inserted through the open center of the sleeve  284 . The sections  66  and  68  of the suture  52  are then wrapped around the conical body  242  in the grooves  258  and  260 . The sleeve  284  may then be moved along the suture  252  to the desired position in a patient&#39;s body.  
         [0126]     It is believed that it will be preferred to position the left and right sections  66  and  68  of the suture  52  relative to the body tissue before winding the two sections of the suture around the body  242 . However, one of the sections  66  or  68  of the suture  52  may be wound around the body  242  and inserted through the sleeve  284  before the suture is positioned relative to the body tissue. After the suture  52  has been positioned relative to the body tissue, the other section of the suture would be inserted through the sleeve  284  and wound around the body  242 .  
         [0127]     When the suture  52  has been positioned relative to the body tissue and suture retainer  244 , the sections  66  and  68  of the suture  52  are tensioned as a force  296  ( FIG. 13 ) is applied to the conical body  242 . The force  296  is sufficient to cause the conical body  242  of the suture retainer  244  to slide axially along the sections  66  and  68  of the suture toward the sleeve  284 . As this occurs, the outer side surface  248  on the conical body  242  moves into engagement with the inner side surface  288  on the sleeve  284 . The force  296  is then effective to press the outer side surface  248  on the conical body  242  firmly against the inner side surface  288  of the sleeve.  
         [0128]     The force  296  is also effective to press both the end surface  254  of the conical body  242  and an annular end surface  300  of the sleeve  284  against the body tissue. While the left and right sections  66  and  68  of the suture are tensioned, the force  296  is increased. After the suture retainer  244  has been pressed against the body tissue with a predetermined force  296  sufficient to cause the suture  52  to grip the body tissue with a desired tension, force applicator members, similar to the force applicator members  224 ,  226  and  228  of  FIG. 12 , compress the sleeve  284 . The manner in which force is applied against the sleeve  284  is indicated schematically by arrows  302  and  304  in  FIG. 13 . If desired, one or more axial slot may be provided through a portion of the sleeve  284  to facilitate compression of the sleeve.  
         [0129]     The force applied against the sleeve  284 , indicated schematically at  302  and  304 , causes radially inward plastic deformation of the sleeve. This force is transmitted through the sleeve to the conical body  242 . The force transmitted to the conical body  242  causes a collapsing of the grooves  258  and  260 . As the grooves  258  and  260  collapse, the material of the conical body  242  is plastically deformed and firmly grips or bonds to the outer side surfaces of the left and right sections  66  and  68  of the suture  52 . The sleeve  284  bonds to the material of the conical body  242 .  
         [0130]     The sleeve  284  and conical body  242  of the suture retainer  244  are at a temperature below the transition temperature of the material forming the sleeve and conical body when they are compressed by the force indicated schematically at  302  and  304  in  FIG. 13 . This results in cold flowing of the material of both the sleeve  284  and the suture retainer  244  under the influence of the force  302  and  304 . The force  302  and  304  is maintained at a predetermined magnitude for a time sufficient to result in cold plastic deformation of the material of the sleeve  284  and conical body  242 . This plastic deformation or cold flow of the material of the sleeve  284  and conical body  242  occurs at a temperature which is substantially the same as the temperature of the body tissue with which the suture  52  is connected.  
         [0131]     If desired, cold flowing of the material of the sleeve  284  and conical body  244  could be promoted by the addition of heat. Thus, the sleeve  284  and conical body  244  may be preheated before being moved into engagement with the body tissue. If desired, heat could be transmitted to the sleeve  284  and conical body  242  during application of he force  302  and  304 . During the application of the force  302  and  304  to the sleeve  284 , both the conical body  242  and sleeve  284  are at a temperature below the transition temperature of the material of the conical body and sleeve.  
         [0132]     Once the suture retainer  284  has been plastically deformed to securely grip the suture  52 , the suture may be knotted. Thus, a knot may be formed in the upper (as viewed in  FIG. 13 ) end portions  66  and  68  of suture  52 . The knot would pull the sections  66  and  68  of the suture firmly against the upper side surface  252  of the conical body  242 . This knot would not decrease the overall force transmitting capability of the suture  52  since the suture retainer  244  would be disposed between the knot and the body tissue. Although such a knot would provide additional assurance that the suture will not work loose, it is believed that the knot is not necessary.  
         [0133]     The tension in the suture  52  will press the annular end surface  300  on the sleeve  284  and the circular end surface  254  on the conical body  242  against the body tissue. Due to the relative large combined area of the end surfaces  254  and  300 , the tension forces in the suture  52  will be applied to a relatively large area on the body tissue by the suture retainer  244 . Since the suture retainer  244  applies force to a relatively large surface area on the body tissue and since the overall strength of the suture  52  is not impaired by the suture retainer  244 , relatively large forces can be transmitted through the suture to the body tissue.  
         [0134]     In the embodiment of the invention illustrated in  FIGS. 13-16 , the helical grooves  258  and  260  cross. This results in the left and right sections  66  and  68  of the suture  52  being disposed in overlapping engagement at the intersections between the grooves  258  and  260 . The overlapping engagement of the left and right sections  66  and  68  of the suture  52  increases the resistance of the suture retainer  244  to slipping of one section of the suture relative to the other section of the suture.  
       Embodiments of FIGS.  17 - 19   
       [0135]     In the embodiment of the invention illustrated in  FIGS. 13-16 , the central axis of the conical body  242  of the suture retainer  244  extends along the sections  66  and  68  of the suture  52 . In the embodiments of the invention illustrated in  FIGS. 17-19 , a central axis of a circular body of the suture retainer extends transverse to the longitudinal axis of the suture during movement of the suture retainer toward the body tissue. Since the suture retainer of the embodiments of the invention illustrated in  FIGS. 17-19  is similar to the suture retainer of the embodiment of the invention illustrated in  FIGS. 13-16 , similar terminology will be utilized to identify similar components. It should be understood that one or more features of the embodiments of the invention illustrated in  FIGS. 1-16  may be used with the embodiments of the invention illustrated in  FIGS. 17-19 .  
         [0136]     A suture retainer  312  ( FIGS. 17 and 18 ) includes a cylindrical housing  314  and a rotatable cylinder  316 . The housing  314  encloses the rotatable cylinder  316 . The rotatable cylinder  316  has a central axis which is coincident with the central axis of the cylindrical housing  314 .  
         [0137]     The cylinder  316  is supported for rotation relative to the housing  314  by bearing sections  320  and  322  ( FIG. 17 ). The bearing sections  320  and  322  are integrally formed as one piece with the housing  314 . The bearing sections  320  and  322  have a conical configuration and engage conical recesses formed in opposite ends of the rotatable cylinder  316 . The bearing sections  320  and  322  support the cylinder  316  in a coaxial relationship with the housing  314 .  
         [0138]     Left and right sections  66  and  68  of the suture  52  extend into the housing  314  through cylindrical openings  326  and  328 . The sections  66  and  68  of the suture  52  extend from the housing  314  through openings  330  and  332 . The openings  326 ,  328 ,  330  and  332  have parallel central axes which extend tangentially to the cylinder  316 .  
         [0139]     The left section  66  of the suture  52  extends through the opening  326  into the housing  314 . The left section  66  of the suture  52  is wrapped in a clockwise direction (as viewed in  FIG. 18 ) around the cylinder  316  and extends from the housing  314  through the opening  330 . Similarly, the right section  68  ( FIG. 17 ) of the suture  52  extends into the housing  314  through the opening  328 . The right section  68  of the suture  52  is wrapped in a counterclockwise direction, as viewed in  FIG. 18 , around the cylinder  316 . The turns in the left and right sections  66  and  68  in the suture  52  are axially spaced apart along the cylindrical outer side surface of the cylinder  316 . If desired, helical grooves may be provided in the cylinder  316  to receive the turns of the left and right sections  66  and  68  of the suture.  
         [0140]     The cylindrical housing  314  is formed of a biodegradable polymeric material. The cylinder  316  is also formed of a biodegradable polymeric material. However, the material of the cylinder  316  is harder than the material of the housing  314 . The material of the cylinder  316  has a lower coefficient of friction than the material of the housing  314 . The material of the housing  314  is easier to plastically deform than the material of the cylinder  316 . Of course, the housing and cylinder  314  and  316  may be formed of the same material which may be biodegradable (polycaperlactone) or may not be biodegradable.  
         [0141]     When the suture retainer  312  is to be positioned relative to body tissue (not shown), the left and right sections  66  and  68  of the suture are tensioned. The housing  312  is then pushed downward (as viewed in  FIGS. 17 and 18 ) in the manner indicated schematically by an arrow  336  in  FIG. 18 . As this occurs, the turns or wraps of the sections  66  and  68  of the suture slide along a cylindrical outer side surface of the rotatable cylinder  316 . The oppositely wound loops in the sections  66  and  68  of the suture  52  move downward along the suture toward the body tissue as the retainer  312  moves downward along the suture toward the body tissue.  
         [0142]     Although there will be some rotational movement of the cylinder  316  relative to the housing  314 , the position of the cylinder  316  relative to the housing  314  remains substantially constant during a major portion of the movement of the suture retainer  312  along the suture  52  toward the body tissue. This is because the left and right sections  66  and  68  of the suture are wrapped in opposite directions around the cylinder  316 . This results in the portion of the loop in the left section  66  of the suture tending to rotate the cylinder  316  in a counterclockwise direction (as viewed in  FIG. 18 ). At the same time, the loop formed in the right section  68  of the suture  52  tends to rotate the cylinder  316  in a clockwise direction (as viewed in  FIG. 18 ).  
         [0143]     Since the two sections  66  and  68  of the suture  52  tend to urge the cylinder  316  to rotate in opposite directions, the cylinder tends to remain more or less stationary relative to the housing  314 . The loops in the left and right sections  66  and  68  of the suture  52  slide along the cylindrical outer side surface of the cylinder  316 . However, it should be understood that there will be some rotational movement of the cylinder  316  relative to the housing  314  as the suture retainer  312  is moved toward the body tissue.  
         [0144]     Once the housing  314  of the suture retainer  312  is moved into engagement with the body tissue, the tension is maintained in the sections  66  and  68  of the suture  52 . The force  336  ( FIG. 18 ) pressing the suture retainer  312  against the body tissue is increased. The suture retainer  312  is pressed against the body tissue with a force, indicated schematically by the arrow  336  in  FIG. 18 , which is sufficient to provide a desired tension in the portion of the suture  52  engaging the body tissue.  
         [0145]     The material of the suture retainer  312  is then plastically deformed. The plastic deformation of the suture retainer  312  is accomplished by applying force against opposite sides of the housing  314  with a pair of force application members  340  and  342  ( FIG. 18 ). The force applied against the suture retainer  312  by the force application members  340  and  342  presses the material of the housing  314  against the sections  66  and  68  of the suture and the cylinder  316  by cold flowing material of the housing.  
         [0146]     A large gap has been shown between the cylindrical outer side surface of the cylinder  316  and a cylindrical inner side surface of the housing  314  in  FIG. 18 . However, it should be understood that this annular gap will be relatively small so that the material of the housing  314  can readily cold flow into engagement with the turns of the sections  66  and  68  of the suture  52  and cylinder  316 . The force applied against the housing  314  also plastically deforms and causes cold flowing of the material of the cylinder  316  to provide a secure bond or grip between the material of the cylinder  316  and the suture  52 .  
         [0147]     A transducer or load cell  346  is associated with the force application member  342  and provides an output to a display unit  348 . After a predetermined minimum force has been applied to the suture retainer  312  by the force application members  340  and  342  for a predetermined minimum length of time, an output from the display unit  348  to an indicator  350  activates the indicator to provide a signal that the desired plastic deformation of the suture retainer  312  has been obtained.  
         [0148]     If desired, a knot may be tied between the left and right sections  66  and  68  of the suture  52  adjacent to a side of the housing  314  opposite from a side of the housing which is pressed against the body tissue by the suture. The knot would be pulled tight against the housing at a location between the openings  326  and  328 . Since the suture retainer  312  is between the knot and the body tissue, the knot would not impair the force transmitting capability of the suture  52 .  
         [0149]     In  FIGS. 17 and 18 , the sections  66  and  68  of the suture  52  are wrapped in opposite directions around the cylinder  316 . This results in offsetting forces being applied to the cylinder  316  by the turns in the sections  66  and  68  of the suture  52  during movement of the suture retainer  312  along the suture toward the body tissue. In  FIG. 19 , the left and right sections  66  and  68  of the suture  52  are wrapped in the same direction around the cylinder  316 . This results in the turns or loops in the sections  66  and  68  of the suture  52  applying force to the cylinder  316  urging the cylinder to rotate in the same direction during movement of the suture retainer  312  along the sections  66  and  68  of the suture toward body tissue. Therefore, when the sections  66  and  68  of the suture  52  are wrapped in the same direction around the cylinder  316 , the cylinder will freely rotate relative to the housing  314  as the suture retainer  312  is moved along the suture  52  toward the body tissue.  
         [0150]     The overall force transmitting capability of the suture  52  is not impaired by the suture retainer  312 . This is because the turns of the loops formed in the left and right sections of the suture  52  around the cylinder  316  do not form stress concentrations in the suture. If a knot had been used to interconnect the left and right sections  66  and  68  of the suture  52 , in the manner taught by the prior art, the resulting stress concentration would reduce the overall force transmitting capability of the suture  52 .  
         [0151]     The cylindrical housing  314  increases the surface area on body tissue against which force is applied by tension in the suture  52  after the suture retainer  312  has been plastically deformed to grip the suture. This increases the amount of force which may be transmitted through the suture  52  without damaging the body tissue.  
       Embodiment of FIG.  20   
       [0152]     In the embodiment of the invention illustrated in  FIGS. 17-19 , the cylinder  316  is rotatable relative to the housing  314 . In the embodiment of the invention illustrated in  FIG. 20 , cylinders are fixedly connected with the housing. Since the embodiment of the invention illustrated in  FIG. 20  is similar to the embodiment of the invention illustrated in  FIGS. 17-19 , similar terminology will be utilized to identify similar components. It should be understood that one or more features of the embodiments of the invention illustrated in  FIGS. 1-19  may be used with the embodiment of the invention illustrated in  FIG. 20 .  
         [0153]     A suture retainer  356  includes a rectangular housing  358  which encloses a plurality of cylinders  360 ,  362 ,  364  and  366 . The cylinders  360 - 366  have parallel central axes which extend parallel to flat rectangular upper and lower side walls  370  and  372  of the housing  358 . Opposite end portions of the cylinders  360 - 366  are fixedly connected with rectangular end walls (not shown) of the housing  358 . The central axes of the cylinders  360 - 366  extend perpendicular to the housing end walls to which the cylinders are fixedly connected.  
         [0154]     In the embodiment of the invention illustrated in  FIG. 20 , the cylinders  360 - 366  are formed of a biodegradable material which is relatively hard. The housing  358  is formed of a biodegradable material which is relatively soft. By forming the housing  358  of a biodegradable material which is relatively soft, plastic deformation of the housing is facilitated. The relatively hard biodegradable material forming the cylinders  360 - 366  has a low coefficient of friction. Although it is preferred to form the cylinders  360 - 366  and housing  358  of biodegradable materials having different hardnesses, the cylinders and housing could be formed of biodegradable or nonbiodegradable materials having the same hardness if desired.  
         [0155]     A suture  52  has left and right sections  66  and  68  which are wrapped around the cylinders  360 - 366  in a zig-zag fashion. Thus, the left section  66  of the suture  52  is looped around the cylinders  360  and  362 . The right section  68  of the suture  52  is looped around the cylinders  364  and  366 . The cylinders  360  and  362  maintain a pair of smooth, continuous bends in the left section  66  of the suture  52 . Similarly, the cylinders  364  and  366  maintain a pair of smooth, continuous bends in the right section  68  of the suture  52 . The smooth, continuous bends in the sections  66  and  68  of the suture  52  are free of stress inducing discontinuities. If desired, a greater or lesser number of bends could be maintained in the sections  66  and  68  of the suture  52  by a greater or lesser number of cylinders.  
         [0156]     In the embodiment of the invention illustrated in  FIG. 20 , there is a single partial turn of the left section  66  of the suture around each of the cylinders  360  and  362 . Similarly, there is a single partial turn of the right section  68  of the suture  52  around each of the cylinders  364  and  366 . If desired, a plurality of turns or loops could be provided around each of the cylinders  360 - 366  by the sections  66  and  68  of the suture  52 . For example, the left section  66  of the suture  52  could be wrapped for one complete revolution around the cylinder  360  and then wrapped for a partial revolution around the cylinder  360  before extending to the cylinder  362 . Similarly, the right section  68  of the suture  52  could be wrapped for one complete revolution around the cylinder  366  and then wrapped for a partial revolution around the cylinder  364  before exiting from the housing  358 .  
         [0157]     After the suture  52  has been wrapped around the cylinders  360 - 366  in the manner illustrated schematically in  FIG. 20 , the suture retainer  356  is moved along the sections  66  and  68  of the suture  52  toward body tissue. As the housing  358  is moved downward (as viewed in  FIG. 20 ), toward the body tissue, the left and right sections  66  and  68  of the suture  52  slide along the outer side surfaces of the cylinders  360 - 366 . As this occurs, the cylinders  360 - 366  cooperate to maintain a plurality of bends in each of the sections  66  and  68  of the suture  52 .  
         [0158]     Once the housing  358  has been pressed against the body tissue with a predetermined force  376  while a predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 , the housing  358  is plastically deformed to grip the suture  52 . Thus, force, indicated by arrows  380  and  382  in  FIG. 20  supplied against a side of the housing  358  opposite from the force  376 . This force is effective to plastically deform the material of the housing and to press the material of the housing against the cylinders  360 - 366  and against the sections  66  and  68  of the suture  52 .  
         [0159]     As the forces indicated by the arrows  376 ,  380  and  382  plastically deform the housing  358 , the material of the housing cold flows under the influence of the force. This cold flow of the material of the housing results in the left and right sections  66  and  68  of the suture being firmly pressed against the cylinders  360 - 366  to form a solid bond with the left and right sections  66  and  68  of the suture  52 . Since the material forming the cylinders  360 - 366  is relatively hard, compared to the material forming the housing  358 , the housing will deform to a greater extent than the cylinders during cold flow of the material of the housing. However, there will be some plastic deformation of the cylinders  360 - 366 .  
         [0160]     The force transmitting capability of the suture  52  is enhanced by minimizing stress concentrations in the suture and by transmitting force from the housing  358  to a large area on the body tissue. The bends formed in the suture  52  around the cylinders  360 - 366  are free of abrupt stress inducing discontinuities. The housing  358  transmits force to the body tissue located between the opposite sides of the left and right sections  66  and  68  of the suture  52 . Therefore, stress concentrations in both the body tissue and the suture  52  tend to be minimized. If desired, a knot may be tied between the upper (as viewed in  FIG. 20 ) end portions of the left and right sections  66  and  68  of the suture  52 . Although such a knot would provide additional assurance that the suture  52  will not work loose, it is believed that the knot will not be necessary.  
         [0161]     One of the ends of the suture could be fixedly connected with the housing  358 . This could be done by forming the suture  52  as one piece with the housing  358  or by using a fastener. If one end of the suture is fixedly connected with the housing  358 , one of the sets of cylinders, for example, the cylinders  360  and  362 , could be eliminated.  
       Embodiment of FIGS.  21 - 22   
       [0162]     In the embodiments of the invention illustrated in  FIGS. 9-20 , bends are formed in the left and right sections  66  and  68  of the suture  52  by circular surfaces. In the embodiment of the invention illustrated in  FIGS. 21 and 22 , the bends are formed in the suture by passages through a rectangular member. Since the embodiment of the invention illustrated in  FIGS. 21 and 22  is similar to the embodiment of the invention illustrated in  FIGS. 9-20 , similar terminology will be utilized to identify similar components. It should be understood that one or more of the features of the embodiments of the invention illustrated in  FIGS. 1-20  may be used with the embodiment of the invention illustrated in  FIGS. 21-22 .  
         [0163]     A suture retainer  390  is formed in a single rectangular piece of biodegradable material. The suture retainer  390  includes a rectangular body  392  formed of a suitable biodegradable material. However, the rectangular body  392  could be formed of a non-biodegradable material if desired.  
         [0164]     A plurality of parallel passages  394 ,  396  and  398  extend between opposite parallel rectangular end surfaces  400  and  402  of the body  392 . The left and right sections  66  and  68  of the suture  52  zig-zag through the passages  394 ,  396  and  398  in a side-by-side relationship. The sections  66  and  68  of the suture  52  zig-zag through the passages  394 ,  396  and  398  to form a series of bends in the suture.  
         [0165]     The passages  394 ,  396  and  398  in the body  392  of the suture retainer  390  cooperate to form smooth, continuous bends  406 ,  408 ,  410  and  412  ( FIG. 21 ) in the sections  66  and  68  of the suture  52 . Thus, the left and right sections  66  and  68  of the suture  52  extend through the straight passage  394 . Bends  406  and  408  are formed in the portions of the sections  66  and  68  of the suture disposed between the passage  394  and the passage  396 . Similarly, bends  410  and  412  are formed in the sections  66  and  68  of the suture  52  disposed between the passages  396  and  398 . Of course, if there were additional passages formed in the rectangular body  392 , additional bends would be formed in the suture  52 .  
         [0166]     The bends  406 - 412  in the sections  66  and  68  of the suture  52  are smooth and free of stress inducing discontinuities. By keeping the suture  52  free of stress inducing discontinuities, the force which can be transmitted through the suture tends to be maximized. If a knot was substituted for the suture retainer  390 , stress concentrations would be formed and the force transmitting capability of the suture reduced.  
         [0167]     The passage  394  has a main section  418  and a gripping section  420 . The gripping section  420  has a tapered configuration ( FIG. 22 ) and extends sideward from the main section  418 . The left and right sections  66  and  68  of the suture  52  may be pulled from the main section  418  of the passage  394  into the gripping section  420  of the passage. As this occurs, the side surfaces of the passage  394  grip opposite sides of the left and right sections  66  and  68  of the suture  52  to hold the left and right sections of the suture against axial movement relative to the rectangular body  392  of the suture retainer  390 .  
         [0168]     The suture retainer  390  is formed of a single piece of biodegradable material, such as polycaperlactone. Of course, other suitable biodegradable or bioerodible materials could be utilized if desired. It is contemplated that the suture retainer  390  could be formed of materials which do not biodegrade.  
         [0169]     After the suture  52  has been inserted into the suture retainer  390 , in the manner illustrated schematically in  FIG. 21 , the suture retainer is moved along the suture toward body tissue (not shown). As the suture retainer  390  is moved along the suture  52 , the side-by-side sections  66  and  68  of the suture slide in the same direction on surfaces of the suture retainer  390 .  
         [0170]     To effect movement of the suture retainer  390  along the suture  52 , force is applied against the body  392 , in the manner indicated schematically by an arrow  424  in  FIG. 21 . This causes the body  392  of the suture retainer  390  to slide along the sections  66  and  68  of the suture  52 . At this time, the left and right sections  66  and  68  of the suture are tensioned. Therefore, the left and right sections of the suture slide along surfaces of the passages  394 ,  396  and  398  as the rectangular body  392  of the suture retainer  390  is moved toward the body tissue. As this occurs, the bends  406 - 412  move along the sections  66  and  68  of the suture  52  toward the body tissue.  
         [0171]     When the leading end surface  402  on the rectangular body  392  of the suture retainer  390  engages the body tissue, the force indicated schematically by the arrow  424  is increased to a predetermined force. As this occurs, a predetermined tensioning force is applied to the left and right sections  66  and  68  of the suture  52 . This results in the suture  52  being pulled tight to grip the body tissue with a desired force. The rectangular end surface  402  on the body  392  of the suture retainer  390  distributes the tension force in the suture  52  over a relatively large area on the body tissue.  
         [0172]     While the retainer body  392  is being pressed against the body tissue with the predetermined force and the left and right sections  66  and  68  of the suture  52  are pulled taut with a predetermined tensioning force, the left and right sections  66  and  68  of the suture may be pulled towards the right (as viewed in  FIGS. 21 and 22 ). As this occurs, the left and right sections  66  and  68  of the suture  52  will move from the main section  418  of the passage  394  into the gripping section  420  of the passage. This results in a frictional grip between the retainer body  392  and the suture  52  to hold the suture against movement relative to the retainer body and to maintain the desired tension in the suture.  
         [0173]     While the body  392  of the suture retainer  390  is being pressed against the body tissue with the predetermined force  424  and while the predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 , the material of the suture retainer  390  is plastically deformed. To plastically deform the material of the suture retainer  390 , force applying members  428  and  430  ( FIG. 22 ) apply a predetermined force against opposite sides of the body  392  of the suture retainer. This force causes cold flowing of the material of the body  392  of the suture retainer.  
         [0174]     As the plastic deformation of the body  392  of the suture retainer  390  occurs, the passages  394 ,  396  and  398  are collapsed and the material of the body  392  of the suture retainer  390  cold flows around and grips the left and right sections  66  and  68  of the suture  52 . The plastic deformation of the body  392  of the suture retainer  390  occurs at a temperature below the transition temperature of the material forming the suture retainer. If desired, the suture retainer  390  could be heated to promote cold flow of the material of the suture retainer.  
         [0175]     In the embodiment of the invention illustrated in  FIGS. 21 and 22 , the gripping section  420  mechanically grips a portion of the suture  52 . If desired, the gripping section  420  could be eliminated and the suture moved into engagement with a projection from the body  392 . The upper (as viewed in  FIG. 21 ) portions of the suture  52  could be wrapped around a projection from the body  392 . Alternatively, the upper (as viewed in  FIG. 21 ) portions of the suture could be moved into engagement with one or more hook-shaped locking notches on the body  392  of the suture retainer  390 .  
       Embodiments of FIGS.  23 - 25   
       [0176]     In the embodiment of the invention illustrated in  FIGS. 21 and 22 , the left and right sections  66  and  68  of the suture  52  extend through the passages  394 ,  396  and  398  in a side-by-side relationship. In the embodiments of the invention illustrated in  FIGS. 23-25 , loops are formed in the left and right sections of the suture around portions of the suture retainer. Since the embodiments of the invention illustrated in  FIGS. 23-25  is similar to the embodiment of the invention illustrated in  FIGS. 21-22 , similar terminology will be utilized to identify similar components. It should be understood that one or more features of the embodiments of the invention illustrated in  FIGS. 1-22  could be used with the embodiments of the invention illustrated in  FIGS. 23-25 .  
         [0177]     A suture retainer  440  ( FIG. 23 ) has a rectangular body  442 . A plurality of straight parallel cylindrical passages  444 ,  446  and  448  extend between flat parallel rectangular end surfaces  450  and  452  of the rectangular body  442  of the suture retainer  440 . The left and right sections  66  and  68  of the suture  52  extend through the passages  444 ,  446  and  448  in a zig-zag manner.  
         [0178]     The left section  66  of the suture  52  zig-zags through the passages  444 ,  446  and  448  in the rectangular body  442  of the suture retainer  440 . When the left section  66  of the suture  52  is inserted into the suture retainer  440 , the left section  66  of the suture is first moved downward (as viewed in  FIG. 23 ) through passage  448 . A smooth, continuous first bend  456  is then formed in the left section  66  of the suture  52  and the left section is moved upward through the passage  446 . A smooth, continuous second bend  458  is then formed in the left section  66  of the suture  52 . The left section  66  of the suture  52  is then moved downward through the passage  444 .  
         [0179]     The right section  68  of the suture  52  is also inserted into the suture retainer  440  in a zig-zag fashion. Thus, the right section  68  of the suture  52  is moved downward through the passage  444 . A smooth, continuous first bend  462  is formed in the right section  68  of the suture  52 . The right section  68  of the suture  52  is then moved upward through the passage  446 . A smooth, continuous second bend  464  is then formed in the right section  68  of the suture  52 . The right section  68  of the suture  52  is then moved downward through the passage  448 .  
         [0180]     In the embodiment of the invention illustrated in  FIG. 23 , the left and right sections  66  and  68  of the suture  52  are not aligned or in a side-by-side relationship with each other. Thus, the bends  456  and  458  in the left section  66  of the suture  52  are offset from the bends  462  and  464  in the right section  68  of the suture  52 . The bends  456 ,  458 ,  462 , and  464  are free of stress inducing discontinuities which would tend to weaken the suture  52 .  
         [0181]     After the suture  52  has been inserted into the suture retainer  440 , in the manner illustrated schematically in  FIG. 23 , the left and right sections  66  and  68  of the suture are tensioned and force is applied to the rectangular body  442  of the suture retainer  440  to move the suture retainer along the suture  52  toward the body tissue. As this occurs, the left and right sections  66  and  68  of the suture  52  slide in opposite directions along the surfaces of the passages  444 ,  446  and  448 . As this occurs, the zig-zag portion of the suture  52  is moved along the suture toward the body tissue.  
         [0182]     When the rectangular leading end surface  452  of the body  442  of the suture retainer  440  moves into engagement with the body tissue, the suture retainer is pressed against the body tissue with a predetermined force while maintaining a predetermined tension in the left and right sections  66  and  68  of the suture. The suture retainer  440  is then plastically deformed to grip the left and right sections  66  and  68  of the suture  52 . To plastically deform the material of the suture retainer  440 , force is applied against opposite sides of the suture retainer  440 , in the manner indicated by arrows  470  and  472  in  FIG. 23 .  
         [0183]     The force indicated by the arrows  470  and  472  causes cold flow of the material of the suture retainer  440 . The suture retainer  440  is formed from a single piece of biodegradable polymeric material, such as polycaperlactone. The plastic deformation of the suture retainer  440  occurs while the material of the suture is a temperature which is below the transition temperature of the material and is at a temperature close to the temperature of the body tissue. If desired, the suture retainer  440  could be heated to a temperature above the temperature of the body tissue and below the transition temperature of the material of the suture retainer to promote cold flow of the material of the suture retainer.  
         [0184]     In the embodiment of the invention illustrated in  FIG. 24 , the sections of the suture  52  are wrapped around portions of the suture retainer in smooth, continuous loops. Thus, in the embodiment of the invention illustrated in  FIG. 24 , a suture retainer  480  includes a rectangular body  482  formed of a biodegradable polymeric material. A plurality of straight cylindrical passages  484 ,  486  and  488  extend between and are perpendicular to flat parallel end surfaces  492  and  494  on the rectangular body  482  of the suture retainer  480 .  
         [0185]     The suture  52  includes left and right sections  66  and  68 . The left and right sections  66  and  68  are wrapped, in zig-zag fashion, around portions  498  and  500  of the rectangular body  482 . This results in the formation of left and right loops  502  and  504  in the left and right sections  66  and  68  of the suture  52 . The loops  502  and  504  are free of stress inducing discontinuities.  
         [0186]     When the suture retainer  480  is to be positioned relative to the body tissue of a human patient, the left and right sections  66  and  68  of the suture  52  are tensioned with a predetermined force. Force is then applied to the rectangular body  482  of the suture retainer to move the suture retainer downward (as viewed in  FIG. 24 ) along the suture  52 . As this occurs, the left and right sections  66  and  68  slide along surfaces of the passages  484 ,  486  and  488 . In addition, the loops  502  and  504  move downward (as viewed in  FIG. 24 ) along the suture  52 .  
         [0187]     The leading end surface  494  of the rectangular body  482  is pressed against the body tissue with a predetermined force while a predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 . The material of the suture retainer  480  is then plastically deformed to grip the left and right sections  66  and  68  of the suture  52 . When the material of the suture retainer  480  is plastically deformed, the material of the suture retainer is below its transition temperature and is at a temperature close to the temperature of the body tissue. Therefore, the material of the suture retainer  480  cold flows under the influence of force applied against the suture retainer to collapse the passages  484 ,  486  and  488  and grip the left and right sections  66  and  68  of the suture  52 .  
         [0188]     The flat rectangular end surfaces of the suture retainer  480  applies force over a relatively large surface area on the body tissue. This reduces any tendency for the suture  52  to cut or separate the body tissue. The force which can be transmitted through the suture  52  is maximized by eliminating sharp bends in the suture. If the suture retainer  480  was eliminated and the suture was secured with a knot, the suture would be weakened by stress concentrations formed at sharp bends in the knot.  
         [0189]     In the embodiment of the invention illustrated in  FIG. 25 , a suture retainer  510  includes a rectangular body  512  formed of a biodegradable polymeric material. A plurality of straight parallel cylindrical passages  514 ,  516 ,  518 , and  520  extend between flat rectangular end surfaces  522  and  524  of the body  512 .  
         [0190]     The suture  52  includes left and right sections  66  and  68 . Separate left and right loops  530  and  532  ( FIG. 25 ) are formed in the sections  66  and  68  of the suture  52 . Thus, the left loop  530  in the left section  66  of the suture  52  extends through the passages  518  and  520  in the rectangular body  512  of the suture retainer  510 . Similarly, the right loop  532  extends through the passages  514  and  516  in the rectangular body  512  of the suture retainer  510 .  
         [0191]     When the suture retainer  510  is to be positioned relative to body tissue, the left and right sections  66  and  68  of the suture  52  are tensioned. Force is then applied to the suture retainer  510  to move the suture retainer downward (as viewed in  FIG. 25 ) along the suture  52  into engagement with the body tissue. After the lower end surface  524  of the rectangular body  512  of the suture retainer  510  has been pressed against the body tissue with a predetermined force, the biodegradable polymeric material of the suture retainer  510  is plastically deformed by applying force against the suture retainer and cold flowing the material of the suture retainer. Cold flow of the material of the body  512  collapses the passages  514 - 520 . The material of the body  512  then firmly grips the suture  52 .  
         [0192]     After plastic deformation of the material of the body  512 , the suture retainer  510  at a temperature below the transition temperature of the material, a knot may be tied between the upper portions of the suture. This knot would be pressed tightly against the upper end surface  522  of the rectangular body  512  of the suture retainer  510 . This know would be disposed at a location between the locations of the passages  516  and  518  before plastic deformation of the body  512  of the suture retainer  510 . It is believed that such a knot may not be necessary.  
         [0193]     In the embodiment of the invention illustrated in  FIGS. 24 and 25 , the passages through the rectangular bodies of the suture retainer are shorter than the passages through the rectangular body of the suture retainer illustrated in  FIG. 23 . However, it should be understood that the passages through the rectangular bodies of the suture retainers illustrated in  FIGS. 24 and 25  could have a longer length if desired.  
         [0194]     In the embodiments of the invention illustrated in  FIGS. 23-25 , the suture  52  is separate from the suture retainers  440 ,  480  and  510 . However, one end of the suture  52  could be connected with any one of he suture retainers  440 ,  480  and  510 . If this was done only one of the sections  66  or  68  would be zig-zagged through passages in a suture retainer. For example, an end of the left section  66  of the suture  52  may be fixedly connected with one of the suture retainers  440 ,  480  or  510 . Only the right section  68  of the suture  52  would have to be inserted through the passages in the one suture retainer  440 ,  480  or  510 . The end of the suture  52  could be fixedly connected with a suture retainer  440 ,  480  or  5110  by a suitable fastener or by forming the suture as one piece with the suture retainer.  
       Embodiment of the Invention Illustrated in FIGS.  26 ,  27  and  28   
       [0195]     In the embodiment of the invention illustrated in  FIGS. 21-25 , the suture retainer is formed form a single piece of biodegradable polymeric material. In the embodiment of the invention illustrated in  FIGS. 26-28 , the suture retainer is formed from a plurality of pieces of biodegradable polymeric material. Since the embodiment of the invention illustrated in  FIGS. 26-28  is similar to the embodiment of the invention illustrated in  FIGS. 21-25 , similar terminology will be utilized to identify similar components. It should be understood that one or more of the features of the embodiments of the invention illustrated in  FIGS. 1-25  could be used with the embodiment of the invention illustrated in  FIGS. 26-28 .  
         [0196]     A suture retainer  540  ( FIG. 26 ) includes a base  542  ( FIGS. 26 and 27 ) and a sleeve or cap  544  ( FIGS. 26 and 28 ). The base  542  has a circular flange  548  which extends radially outward from an upstanding central or post portion  550  ( FIGS. 26 and 27 ). The post portion  550  has a generally cylindrical configuration and is disposed in a coaxial relationship with the circular flange  548 . The flange  548  and post portion  550  are integrally formed from one piece of a biodegradable material, such as polycaperlactone. However, the base  542  and/or the cap  544  could be formed of a material which is not biodegradable.  
         [0197]     A pair of passages  554  and  556  are provided in the post portion  550 . The passage  554  includes a radially inward and downward sloping entrance portion  558  and a main portion  560 . The main portion  560  extends parallel to the longitudinal central axis of the post portion  550 . The entrance portion  558  of the passage  554  extends inwardly from a cylindrical outer side surface  562  of the post portion  550 . The main portion  560  of the passage  554  extends perpendicular to a flat circular bottom side surface  564  of the flange  548 .  
         [0198]     The passage  556  has the same configuration as the passage  554 . The passage  556  is disposed diametrically opposite to the passage  554 . The passages  554  and  556  have a nonlinear configuration and form bends in he left and right sections  66  and  68  of the suture  52 . The passages  554  and  556  are circumscribed by an annular recess  568  which extends around the lower end of the post portion  550  adjacent to the flange  548 .  
         [0199]     The upper end of the post portion  550  has a flat circular side surface  570  ( FIG. 27 ). The flat side surface  570  on the post portion  550  extends parallel to and is coaxial with the flat bottom side surface  564  ( FIG. 26 ) on the flange  548 . The annular recess  568  is coaxial with the flange  548 . The base portion  542  is formed of a biodegradable material, such as polycaperlactone. Other polymers which are biodegradable or bioerodible may be used. It is also contemplated that the base portion  542  could be formed of a polymer which does not biodegrade, such as an acetyl resin.  
         [0200]     In addition to the base portion  542 , the suture retainer  540  includes the one piece, cylindrical cap or sleeve  544  ( FIG. 28 ). The cap  544  has a cylindrical outer side surface  574 . A circular end surface  576  extends radially inwardly from the side surface  547 . The cap  544  has a cylindrical cavity  578  ( FIG. 26 ) which is disposed in a coaxial relationship with the cylindrical outer side surface  574  and end surface  576 .  
         [0201]     A pair of cylindrical passages  582  and  584  extend between the cavity  578  and the circular end surface  576  of the cap  544  ( FIG. 26 ). The cavity  578  has a cylindrical side surface  588  which is disposed in a coaxial relationship with the outer side surface  574  on the cap  544 . In addition, the cavity  578  has a circular end surface  590  which extends parallel to and is coaxial with the outer end surface  576  on the cap  544  ( FIG. 26 ). An annular rib  594  ( FIG. 26 ) projects radially inward from the cylindrical inner side surface  588  of the cavity  578 . The cap  544  is integrally formed as one piece of a suitable biodegradable polymeric material, such as polycaperlactone. However, the cap  544  may be formed of a material which is not biodegradable.  
         [0202]     When the suture  52  is to be connected with body tissue  54  ( FIG. 26 ), one of the sections of the suture, for example, the right section  68 , is threaded through the passage  582  into the cavity  578  in the cap  544 . At this time, the suture  52  extends away from the cap  544  so that the left section  66  of the suture is disposed at a remote location. The right section  68  of the suture is then threaded through the passage  554  in the base portion  542 . The right section  68  of the suture  52  is then threaded through a passage  598  in the body tissue  54 .  
         [0203]     In addition, the right section  68  of the suture  52  is threaded through a passage  600  in a force distribution member or button  602  which engages a lower side of the body tissue  54 . The suture  52  is then threaded through a second passage  604  in the button  602  and a passage  606  in the body tissue  54 . The button  602  distributes tension forces in the suture  52  over a relatively large area on the lower (as viewed in  FIG. 26 ) side  108  of the body tissue. However, the button  602  could be omitted if desired.  
         [0204]     The right section  68  of the suture is then threaded upward (as viewed in  FIG. 26 ) through the passage  556  in the base portion  542  and into the cavity  578  in the cap  544 . The right section  68  of the suture  52  is threaded out of the cavity  568  through the passage  584 . As this occurs, the left section  66  of the suture  52  is pulled into the cap  544  and base portion  542 .  
         [0205]     Once the suture  52  has been threaded through the base portion  542  and cap  544  in the manner previously explained, the sections  66  and  68  of the suture are tensioned and the base portion  542  is slid along the suture  52 . As this occurs, the bends formed in the left and right sections  66  and  68  of the suture  52  by the passages  554  and  556  in the base portion  542  are moved along the suture toward the body tissue  54 . The bottom side surface  564  of the base portion  542  is then pressed against an upper side surface  98  of the body tissue  54  in the manner illustrated in  FIG. 26 .  
         [0206]     The flat circular bottom side surface  564  of the flange  548  transmits force from the suture  52  to a relatively large area on the surface  98  of the body tissue  54 . At this time, the tension in a connector portion  610  of the suture  52  will pull the force distribution member or button  602  firmly upward against a lower side surface  108  of the body tissue  54 . This results in the body tissue  54  being clamped between the relatively large bottom surface area on the flange  548  and the button  602 .  
         [0207]     While the tension is maintained in the left and right sections  66  and  68  of the suture  52 , the cap  544  is slid downward along the suture  52  into engagement with the base portion  542 . Further downward movement of the sleeve or cap  544  resiliently deflects the rib  594  radially outward. Continued downward movement (as viewed in  FIG. 26 ) of the sleeve or cap  544  moves the rib  594  along the outer side surface  562  of the post portion  542  into alignment with the recess  568 . As this occurs, the rib  594  snaps into the recess  568 .  
         [0208]     Once the rib  594  is snapped into the recess  568 , the left and right sections of the suture  52  are firmly gripped between the cylindrical inner side surface  588  of the cavity  578  in the cap  544  and the cylindrical outer side surface  562  of the post portion  550 . In addition, the left and right sections  66  and  68  of the suture  52  are gripped between the circular end surface  590  of the cavity  578  and the circular end surface  570  of the post portion  550 . The cap  544  and post portion  550  cooperate to form bends in the left and right sections  66  and  68  of the suture.  
         [0209]     Under certain circumstances, it is believed that the mechanical gripping action provided between the cap  544  and base portion  542  of the suture retainer  540  may be sufficient to hold the suture  52  against movement relative to the body tissue. However, it is believed that it will be preferred to enhance the grip of the suture retainer  540  on the suture  52  by plastically deforming the material of the suture retainer. The plastic deformation of the suture retainer  540  occurs with the suture retainer at a temperature which is below the transition temperature of the biodegradable polymeric material forming the base portion  542  and cap  544  of the suture retainer.  
         [0210]     Plastic deformation of the base portion  542  and cap portion  544  of the suture retainer  540  is accomplished by applying force against the cylindrical outer side surface  574  of the cap  544  in the same manner as illustrated schematically in  FIG. 12 . The force applied against the cylindrical outer side surface  574  ( FIG. 26 ) of the cap  544  causes the material of the cap to cold flow and press against the left and right sections  66  and  68  of the suture  52 . As this occurs, the passages  554  and  556  in the base portion  542  collapse. Due to the bends provided in the left and right sections  66  and  68  of the suture  52  in passing through the passages  554  and  556 , and around the outside of the post portion  550  of the base portion  542 , there is an extremely secure gripping action of the suture  52  upon plastic deformation of material of the cap  544  and base portion  542 .  
         [0211]     The force applied against the outer side surface  574  of the cap  544  is sufficient to cause cold flow of the material of the cap  544  and post portion  550 . Cold flow of the material of the cap  544  firmly clamps the sections  66  and  68  of the suture  52  between the cap and post portion  550 . Cold flow of the material of the post portion  550  collapses the passages  554  and  556 . This results in a cold bonding of the material of the post portion  550  with the suture  52 . The suture  52  is then securely gripped by the post portion  554 .  
         [0212]     It is preferred to form the base portion  542  and the cap  544  of the suture retainer  540  of the same biodegradable polymeric material. However, the base portion  542  could be formed of a biodegradable material which is somewhat harder than the biodegradable material forming the cap  544 . This would facilitate plastic deformation of the cap  544  under the influence of force applied against the outer side surface  574  of the cap. If desired, the base portion  542  and/or cap  544  could be formed of a material which does not biodegrade.  
         [0213]     After the suture retainer  540  has been plastically deformed by cold flowing the material of the suture retainer, the suture  52  may be knotted. Thus, a knot may be tied to interconnect the left and right sections  66  and  68  of the suture  52  in a known manner. During the tying of this knot, the suture  52  is pulled taut against the end surfaces  576  on the cap  544 . The knot will be disposed between the passages  582  and  584  in the cap  544 . The knot will not reduce the overall force transmitting capability of the suture  52  since the suture retainer  540  will be disposed between the knot and the body tissue  54 . Although such a knot may be provided to be certain that the suture  52  does not work loose under the influence of varying loads, it is believed that the suture retainer  540  will be very capable of holding the suture  52  without the additional protection provided by the knot.  
       Embodiment of FIG.  29   
       [0214]     In the embodiment of the invention illustrated in  FIGS. 13-16 , the suture  52  is wrapped around a conical body  242  which is moved into a sleeve  284  of a suture retainer  244 . In the embodiment of the invention illustrated in  FIG. 29 , the suture extends through passages formed in a conical body and a sleeve. Since the embodiment of the invention illustrated in  FIG. 29  is similar to the embodiment of the invention illustrated in  FIGS. 13-16 , similar terminology will be utilized to identify similar components. It should be understood that one or more of the features of the embodiments of the invention illustrated in  FIGS. 1-28  could be used with the embodiment of the invention illustrated in  FIG. 29 .  
         [0215]     A suture retainer  622  includes a conical body  624  and a cylindrical sleeve or base  626 . The conical body  624  has an outer side surface  628  which is formed as a portion of a right circular cone. The outer side surface  628  of the conical body  624  extends between flat parallel circular end surfaces  630  and  632 . The end surfaces  630  and  632  are disposed in a coaxial relationship with each other and with the outer side surface  628  of the conical body  624 . The end surface  632  of the conical body  624  has a diameter which is smaller than the diameter of the end surface  630  of the conical body.  
         [0216]     A pair of cylindrical passages  636  and  638  are disposed in the conical body  624 . The passages  636  and  638  have straight central axes which are skewed at an acute angle to the central axis of the conical body  624 . If desired, the passages  636  and  638  could have nonlinear central axes to promote the forming of bends in the suture  52 . For example, the passages  636  and  638  could have a helical configuration. The conical body  624  is formed from a single piece of a biodegradable polymeric material, such as polycaperlactone.  
         [0217]     The cylindrical sleeve  626  has a cylindrical outer side surface  642 . The side surface  642  extends between a flat annular end surface  644  and a circular end surface  646 . The end surfaces  644  and  646  extend parallel to each other and are disposed in a coaxial relationship.  
         [0218]     A recess  650  is formed in the cylindrical sleeve  626 . The recess  650  is of the same size and configuration as the conical body  624 . The recess  650  has a side wall  652  which is formed as a portion of a cone. In addition, the recess  650  has a circular end surface  654  which extends parallel to the outer end surface  646  on the sleeve  626 . The side wall  652  of the recess  650  has the same angle of taper as the outer side surface  628  of the conical body  624 . However, if desired, the taper in the side wall  652  of the recess  650  could be slightly less than the taper in the outer side surface  628  of the conical body  624  to promote a wedging action between the conical body and the sleeve  626 .  
         [0219]     A pair of parallel cylindrical passages  660  and  662  extend between and are perpendicular to the end wall  654  of the recess  650  and the end surface  646  on the sleeve  626 . The passages  660  and  662  have a linear configuration. However, the passages  660  and  662  could have a nonlinear configuration if desired.  
         [0220]     When the suture retainer  622  is to be positioned relative to body tissue, the left section  66  of the suture  52  is inserted through the passage  660  in the sleeve  626 . The left section  66  of the suture  52  is then inserted through the passage  636  in the conical body  624 . Similarly, the right section  68  of the suture  52  is inserted through the passage  662  in the sleeve  626  and the passage  638  in the conical body  624 .  
         [0221]     The left and right sections  66  and  68  of the suture  52  are then tensioned and the sleeve  626  is moved along the suture  52  into engagement with the body tissue. When the end surface  646  of the sleeve has engaged the body tissue, the force applied against the sleeve and tension in the sections  66  and  68  of the suture  52  are increased. While a predetermined force is applied against the sleeve  626 , the conical body  624  is moved along the left and right sections  66  and  68  of the suture  52  into the recess  650  in the sleeve. As this occurs, the left and right sections  66  and  68  of the suture are clamped between the outer side surface  628  of the conical body  624  and the conical side wall  652  of the recess  650 .  
         [0222]     To enhance the gripping action between the conical body  624  and the sleeve  626 , force is applied against the cylindrical outer side surface  642  of the sleeve in the same manner as indicated schematically in  FIG. 12 . This force causes plastic deformation of the material of the sleeve  626  to firmly grip the conical body  624  and the left and right sections  66  and  68  of the suture  52 . The force applied against the outer side surface  642  of the sleeve  626  causes a cold flowing of the material of the sleeve  626 . The cold flowing of the material of the sleeve  626  will collapse the passages  660  and  662  to firmly grip the portion of the left and right sections  66  and  68  of the suture  52  extending through the passages.  
         [0223]     In addition, the force applied against the sleeve  626  will be sufficient to cause plastic deformation, that is, cold flowing, of the material of the conical body  624  to collapse the passages  636  and  638 . This results in the portions of the left and right sections  66  and  68  of the suture  52  disposed in the passages  636  and  638  being firmly gripped by material of the conical body  624 .  
         [0224]     It is contemplated that one end of the suture  52  could be fixedly connected with the suture retainer  622 . Thus, one end of the suture  52  could be fixedly connected with the conical body  624 . Alternatively, one end of the suture  52  could be fixedly connected with the sleeve  626 .  
         [0225]     It is also contemplated that a knot could be tied between the left and right sections  66  and  68  of the suture  52  at a location above (as viewed in  FIG. 92 ) the suture retainer. The knot would be tied adjacent to the end surface  650  on the conical body  624 . The knot would be tied immediately after plastically deforming the material of the suture retainer. It should be understood that the suture retainer  622  should be more than adequate to hold the suture  52  and the knot may be omitted.  
         [0226]     The use of the suture retainer  622 , rather than forming a knot to interconnect the two sections  66  and  68  of the suture  52 , increases the force transmitting capability of the suture  52 . This is because the stress concentrations induced by the forming of a knot are avoided.  
         [0227]     In addition, the use of the suture retainer  62 , rather than forming a knot to interconnect the two sections  66  and  68  of the suture  52 , reduces stress concentrations in the body tissue. The flat end surface  646  distributes tension forces in the suture  52  over a relatively large surface area on the body tissue. This minimizes stress concentrations in the body tissue and minimizes any tendency for the body tissue to be cut or separated by the force applied against the body tissue.  
       Embodiment of FIGS.  30  and  31   
       [0228]     In the embodiment of the invention illustrated in  FIG. 29 , the left and right sections  66  and  68  of the suture  52  are inserted into passages formed in the conical body  624 . In the embodiment of the invention illustrated in  FIGS. 30 and 31 , the conical body  34  has a hinge section which is pivotal to open the conical body and facilitate insertion of the left and right sections of the suture. Since the embodiment of the invention illustrated in  FIGS. 30 and 31  is similar to the embodiment of the invention illustrated in  FIG. 29 , similar terminology will be utilized to identify similar components. It should be understood that one or more of the features of the embodiments of the invention illustrated in  FIGS. 1-29  could be used with the embodiment of the invention illustrated in  FIGS. 30 and 31 .  
         [0229]     A suture retainer  670  ( FIG. 30 ) includes a conical body  672  and a sleeve  674 . The conical body  672  is formed as two sections  676  and  678  ( FIG. 31 ). The sections  676  and  678  of the conical body are pivotally interconnected at a hinge  680 . The hinge  680  is integrally formed as one piece with the sections  676  and  678  of the conical body  672 . The hinge  680  enables the left and right sections  66  and  68  ( FIG. 30 ), of the suture  52  to be inserted through an opening  684 . The opening  684  extends between axially opposite ends of the conical body  672 .  
         [0230]     The sleeve  674  includes a circular flange  688  which extends radially outward from a cylindrical outer side surface  690  of the sleeve  674 . A conical recess  692  has a relatively large open end in an upper annular end surface  694  of the sleeve  674  and a relatively small open end in a flat annular end surface  696  disposed on the bottom of the flange  688 .  
         [0231]     The left and right sections  66  and  68  of the suture are inserted through the open ended conical recess  692  in the sleeve  674 . The left and right sections  66  and  68  of the suture  52  are then inserted through the opening  684  ( FIG. 31 ) into the conical body  672 .  
         [0232]     While tension is maintained in the left and right sections  66  and  68  of the suture  52 , the sleeve  674  is moved along the suture until the leading end surface  696  on the bottom of the flange  688  engages the body tissue. The sleeve  674  is then pressed against the body tissue with a predetermined force while a predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 . The conical body  672  is then moved along the left and right sections  66  and  68  of the suture  52  into the open ended recess  692  in the sleeve  674 .  
         [0233]     Force is then applied against the outer side surface  690  of the sleeve  674  to plastically deform the sleeve. As this occurs, the material of the sleeve  674  cold flows radially inward and applies force against the conical body  672 . This force is sufficient to cause cold flowing of the material of the conical body and gripping of the left and right sections  66  and  68  of the suture  52  with the material of the conical body  672 .  
         [0234]     The conical body  672  and sleeve  674  are formed of a biodegradable material. However, the conical body  672  and/or sleeve  674  could be formed of a different material if desired.  
       Embodiment of FIGS.  32  and  33   
       [0235]     In the embodiment of the invention illustrated in  FIGS. 29, 30  and  31 , two-piece suture retainers are utilized to grip the left and right sections of the suture  52 . In the embodiment of the invention illustrated in  FIGS. 32 and 33 , a one-piece tubular suture retainer is utilized to grip the left and right sections of the suture. Since the embodiment of the invention illustrated in  FIGS. 32 and 33  is similar to the embodiment of the invention illustrated in  FIGS. 29-31 , similar terminology will be utilized to identify similar components. It should be understood that one or more of the features of the embodiments of the invention illustrated in  FIGS. 1-31  could be used with the embodiment of the invention illustrated in  FIG. 32 .  
         [0236]     In the embodiment of the invention illustrated in  FIG. 32 , a suture retainer  700  is formed from a single piece of a biodegradable polymeric material, such as polycaperlactone. The suture retainer  700  includes an annular flange or base  702  and an upright tubular cylindrical main section  704 . The tubular cylindrical main section  704  is disposed in a coaxial relationship with the base  702 . A straight cylindrical passage  706  extends through the tubular main section  704  and base  702  of the suture retainer  700 . If desired, the passage  706  could have a nonlinear configuration.  
         [0237]     Left and right sections  66  and  68  of the suture  52  are inserted through the passage  706  in the suture retainer  700 . While a predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 , a predetermined force, indicated schematically by the arrows  708  in  FIG. 32 , is applied to the main section  704  of the suture retainer. The force  708  is distributed over a relatively large surface area on the body tissue  54  by the base  702 .  
         [0238]     The suture retainer  700  is then plastically deformed to grip the left and right sections  66  and  68  of the suture  52 . To plastically deform the suture retainer  700 , force application members  712  and  714  are pressed against opposite sides of the main section  704  of the suture retainer  700  with a predetermined force, indicated schematically by the arrows  716  in  FIG. 32 . When the force  716  is applied to the suture retainer  700 , the suture retainer is at a temperature below the transition temperature of the material forming the suture retainer. Therefore, the force  716  is effective to cause cold flow of the material of the suture retainer  700 .  
         [0239]     The force applied against the suture retainer  700  by the force applying members  712  and  714  is measured by a transducer or load cell  720 . The magnitude of the force  716  is transmitted from the load cell  720  to a display unit  722 . When a predetermined minimum force  716  has been applied to the suture retainer  700  for a predetermined minimum period of time by the force applying members  712  and  714 , the display unit  722  activates an indicator  724 .  
         [0240]     The force applying members  712  and  714  are configured to form a plurality of bends  728  and  730  in the tubular main section  704  of the suture retainer  700  ( FIG. 33 ). Thus, the force applying members  712  and  714  deform the main section  704  of the suture retainer  700  from a straight cylindrical configuration ( FIG. 32 ) to a nonlinear configuration ( FIG. 33 ). The bends  728  and  730 , in combination with the cold plastic deformation of the material of the suture retainer  700 , result in the suture retainer  700  having a firm grip on the left and right sections  66  and  68  of the suture  52 . It should be understood that the force application members  712  and  714  could be configured to form a greater number of bends in the main section  704  of the suture retainer.  
         [0241]     In the illustrated embodiment of the suture retainer  700 , a single passage  706  ( FIG. 32 ) extends through the suture retainer. If desired, a plurality of passages could be provided in the suture retainer  700 . If this was done, the left section  66  of the suture would be inserted through one of the passages and the right section  68  would be inserted through another passage.  
         [0242]     The bends  728  and  730  ( FIG. 33 ) in the suture retainer  700  form smooth, continuous bends in the suture  52 . This avoids the formation of stress concentrations in the suture  52 . If a knot had been utilized in place of the suture retainer  700  to interconnect the sections  66  and  68  of he suture  52 , stress concentrations would have been formed in the suture and the overall force transmitting capability of the suture would have been impaired.  
         [0243]     The annular base  702  projects radially outward from the cylindrical main section. Sine the tension force transmitted to the suture retainer  700  by the suture  52  is transmitted to the body tissue  54  by the base  702 , the suture tension force is transmitted to a relatively large surface area on the body tissue. This minimizes the possibility of the suture  52  and suture retainer  700  being pulled downward (as viewed in  FIG. 33 ) into the body tissue  54  by the tension force in the suture. In addition, the large base  702  minimizes the possibility of damage to the body tissue  54 .  
         [0244]     If desired, a knot could be tied between the upper end portions of the sections  66  and  68  of the suture. This knot would be disposed above and would press against an upper (as viewed in  FIG. 33 ) end of the suture retainer. Although stress concentrations would be formed in the suture  52  at the knot, the knot would not impair the force transmitting capability of the portion of the suture engaging the body tissue  54 . This is because the suture retainer  700  would be disposed between the body tissue  54  and the knot.  
       Embodiment of FIG.  34   
       [0245]     In the embodiment of the invention illustrated in  FIG. 34 , the suture retainer has a tubular configuration. Since the embodiment of the invention illustrated in  FIG. 34  is similar to the embodiments of the invention illustrated in  FIGS. 1-33 , similar terminology will be utilized to identify similar components. It should be understood that one or more of the features of the embodiments of the invention illustrated in  FIGS. 1-33  could be used with the embodiment of the invention illustrated in  FIG. 34 .  
         [0246]     A suture  52  ( FIG. 34 ) has left and right sections  66  and  68  which extend through a tubular cylindrical suture retainer  740  into body tissue  54 . An apparatus  741  for pressing the suture retainer  740  against the body tissue  54  includes a tubular cylindrical plunger  742  having a cylindrical central passage  744  through which the left and right sections  66  and  68  of the suture  54  extends. The plunger  742  is enclosed in a tubular cylindrical housing  746 .  
         [0247]     The plunger  742  is pressed downward, relative to the housing  746  against the suture retainer  740  with a predetermined force, indicated by arrows  748  in  FIG. 34 . An annular transducer or load cell  750  provides an output indicative of the magnitude of the force  748  with which the suture retainer  740  is pressed against the body tissue  54  by the plunger  742 .  
         [0248]     While the left and right sections  66  and  68  of the suture  54  are being tensioned with a predetermined force and while the plunger  742  is being pressed against the suture retainer  740  with a predetermined force, the suture retainer  740  is plastically deformed. To plastically deform the suture retainer  740 , a plurality of force applying or clamp members  754  and  756  are pressed against the suture retainer with a predetermined minimum force, indicated schematically by arrows  760  in  FIG. 34 . The force application members  754  and  756  may have an arcuate configuration to conform to the cylindrical configuration of the suture retainer  740  or may have a flat configuration. The force applied against the suture retainer  740  by the force  760  applying members  754  and  756  is sufficient to cause plastic deformation of the material of the suture retainer.  
         [0249]     The force  760  is applied against the suture retainer while the suture retainer is at a temperature which is below the transition temperature of the biodegradable polymer which forms the suture retainer. Thus, the suture retainer is at approximately the same temperature as the body tissue  54  when the force  760  is applied against the suture retainer. The force  760  causes the material of the suture retainer to cold flow and grip the left and right sections  66  and  68  of the suture  54  in the manner previously explained.  
         [0250]     Although the apparatus  741  has been illustrated in  FIG. 34  in association with the suture retainer  740 , it is contemplated that the apparatus  741  could be used with any one of the suture retainers of  FIGS. 1-33 . Although the force applying members  754  and  756  have an arcuate configuration to grip the arcuate outer side surface of the suture retainer  740 . It is contemplated that the force applying members could have a different configuration to grip a suture retainer having a noncylindrical configuration.  
       Embodiment of FIG.  35   
       [0251]     In the embodiment of the invention illustrated in  FIG. 35 , an apparatus similar to the apparatus illustrated in  FIG. 34  is utilized to install a suture retainer having the same construction as the suture retainer of  FIGS. 13-16 . Since the embodiment of the invention illustrated in  FIG. 35  is similar to the embodiment of the invention illustrated in  FIG. 34 , similar terminology will be utilized to identify similar components.  
         [0252]     An apparatus or tool  770  ( FIG. 35 ) is utilized to position a suture retainer  772  relative to body tissue  54 . The apparatus  770  includes a tubular housing or base  774  through which a cylindrical plunger  776  extends. A force application member  778  extends from the plunger  776  and is engageable with an upper or trailing end surface  780  of the suture retainer  772 . A biasing spring  782  urges the force application member  778  to the extended position illustrated in  FIG. 35 .  
         [0253]     Upon application of a predetermined force to the trailing end surface  780  of the suture retainer  772  by the force application member  778 , an indicator connected with a shaft  786  indicates to an operator of the apparatus  770  that a desired force has been applied against the suture retainer  772 . The indicator may be either a direct reading of the position of the shaft  786  relative to the plunger  776  or an output from a transducer, such as a load cell.  
         [0254]     The apparatus  770  includes a gripper assembly  790  which is operable to grip and to deform the suture retainer  772 . The gripper assembly  790  includes a left force application member  792  and a right force application member  794 . The force application members  792  and  794  engage opposite sides of the suture retainer  772 . The force application members  792  and  794  are configured to correspond to the shape of an outer side surface of the suture retainer  772 .  
         [0255]     An actuator member  798  is connected with the left force application member  792 . A second actuator member  800  is connected with the right force application member  794 . The actuator members  798  and  800  are pivotally mounted on the housing  774  at a pivot connection indicated schematically at  802  in  FIG. 35 .  
         [0256]     Downward force is manually applied to an upper input end portion  806  of the plunger  776  while a predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 . The downward (as viewed in  FIG. 35 ) force applied against the plunger  776  is transmitted through the spring  782  to the force application member  778 . The force application member  778  applies force to the trailing end surface  780  of the suture retainer  772  to press a leading end surface  810  on the suture retainer  772  against the side surface  98  of the body tissue  54 .  
         [0257]     An adjustable stop member  812  is connected with the housing  774 . The stop member  812  is adjustable to limit the extent of downward movement of the input end portion  806  of the plunger  776  relative to the housing  774 . This enables the stop member  812  to limit the amount of force transmitted through the spring  782  to the suture retainer  772  to a predetermined force.  
         [0258]     Manual force is applied against upper (as viewed in  FIG. 35 ) end portions  816  and  818  of the actuator members  798  and  800 . During the application of the manual force to the upper end portions  816  and  818  of the actuator members  798  and  880 , the predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 . In addition, the predetermined downward force is transmitted from the plunger  776  through the spring  782  and force application member  778  to the suture retainer  772 .  
         [0259]     The manual force applied to the end portions  816  and  818  of the actuator members  798  and  800  is transmitted to the force application members  792  and  794 . The force application members  792  and  794  are pressed against the suture retainer  792  with sufficient force too plastically deform the suture retainer by cold flowing the material of the suture retainer.  
         [0260]     Although the suture retainer  772  may have any one of the constructions illustrated in  FIGS. 1-34 , the suture retainer  772  has the same construction as the suture retainer  244  of  FIG. 13 . Thus, the suture retainer  772  includes a conical body  822  and a cylindrical sleeve  824 . The suture  52  has a left section  66  which is wrapped for a plurality of turns around the conical body  822  and is disposed in a helical groove  830  formed in the conical body  822 . Similarly, a right section  68  of the suture  52  is wrapped for a plurality of turns around the conical body  822  and is disposed in a helical groove  832  formed in the conical body  822 .  
         [0261]     When the suture retainer  772  is to be positioned relative to the body tissue  54 , the suture  52  is inserted through the sleeve  824 . The left section  66  of the suture is then positioned in the helical groove  830  in the conical body  822  of the suture retainer  772 . The right section  68  of the suture  52  is positioned in the helical groove  832  in the conical body  822  of the suture retainer  772 .  
         [0262]     The apparatus or tool  770  is then operated to hold the suture retainer  772  in the manner illustrated schematically in  FIG. 35 . Thus, the force application member  778  is positioned in abutting engagement with the trailing end surface  780  of the suture retainer  772 . At the same time, the left and right force application members  792  and  794  grip the sleeve  824  of the suture retainer  772 . This results in the conical body  822  of the suture retainer  772  being telescopically pressed into the sleeve  824  while the sleeve is held by the force application members  792  and  794 .  
         [0263]     While the predetermined tension is maintained in the left and right sections  66  and  68  of the suture  52 , the tool  770  and the suture retainer  772  are moved along the suture  52  toward the body tissue  54 . The tool  770  is moved along a path which extends parallel to the taut portions of the left and right sections  66  and  68  of the suture  52  which extend upward (as viewed in  FIG. 35 ) from the suture retainer  772 . As the suture retainer  772  is moved along the suture  52  toward the body tissue  54 , the left and right sections  66  and  68  of the suture slide along the grooves  830  and  832 . The grooves  830  and  832  are effective to maintain the helical turns or loops in the left and right sections  66  and  68  of the suture  52  as the suture retainer  772  moves along the suture  52  toward the body tissue  54 .  
         [0264]     The force required to slide the suture retainer  772  along the suture  52  is transmitted from the tool  700  to the suture retainer. Thus, force is transmitted from the force application member  778  to the trailing end surface  780  of the conical body  822 . At the same time, a clamping force is transmitted from the force application members  792  and  794  to the sleeve  824 . The sleeve  824  is securely held by the force application members  792  and  794  while the conical body  822  is pressed axially against the sleeve by the force application member  778 . During movement of the suture retainer  772  along the suture  52 , the force applied against the suture retainer by the tool  700  is ineffective to cause significant deformation of the suture retainer.  
         [0265]     At this time, the tool  770  extends along the portions of the left and right sections  66  and  68  of the suture  52  extending upward (as viewed in  FIG. 35 ) from the suture retainer  772 . Since the tool  770  extends from the suture retainer  772  in the same direction as the left and right sections  66  and  68  of the suture  52 , the tool can be used to position the suture retainer relative to body tissue  54  in very restricted space commonly present in operating environments.  
         [0266]     When the leading end surface  810  on the suture retainer  772  engages the upper (as viewed in  FIG. 35 ) side surface  98  of the body tissue  54  ( FIG. 35 ), the force applied against the actuator members  798  and  800  is reduced. Manual force is then applied against the input end portion  806  of the plunger  776  to move the plunger downward and compress the spring  782 . The stop member  812  is engaged by the input end portion  806  of the plunger  776  when a predetermined force is being transmitted through the spring  782  and force application member  778  to the suture retainer  772 .  
         [0267]     This results in the predetermined downward force being transmitted from the force application member  778  to the suture retainer  772  to press the conical body against the sleeve  824 . The predetermined downward force is then transmitted from the sleeve  824  and conical body  822  to the body tissue  54 . While the suture retainer  772  is being pressed against the body tissue with the predetermined downward force, a predetermined tension force is maintained in the left and right sections  66  and  68  of the suture  52 .  
         [0268]     In the schematic illustration of  FIG. 35 , there is space between the conical body  822  and the sleeve  824 . In addition, there is space between the sleeve  824  and the force application members  792  and  794 . It should be understood that the conical outer side surface of the body  822  is pressed firmly against the correspondingly shaped conical inner side surface of the sleeve  824 . It should also be understood hat the force application members  792  and  794  are pressed against the cylindrical outer side surface of the sleeve  824 . At this time, the left and right sections  66  and  68  of the suture are tensioned.  
         [0269]     While the predetermined force is being applied against the trailing end surface  780  of the suture retainer  772  by the force application member  778 , manual force is applied against the upper end portions  816  and  818  of the actuator members  798  and  800  to effect plastic deformation of the suture retainer  772 . Thus, the left and right force applying members  792  and  794  are pressed against the cylindrical sleeve  824  with sufficient force to plastically deform both the cylindrical sleeve and the conical body  822  of the suture retainer  772 . At this time, the suture retainer  772  is at approximately the same temperature as the body tissue  54  and is at a temperature which is below the transition temperature of the biodegradable polymeric material forming the suture retainer. Therefore, cold flowing the material of the suture retainer occurs under the influence of the force applied against the suture retainer  772  by the left and right force applying members  792  and  794 .  
         [0270]     The cold flowing of the material of the suture retainer  772  under the influence of the force applied to the suture retainer by the force application members  792  and  794  results in the suture  52  being firmly gripped in the manner set forth in association with the suture retainer  244  of the embodiment of  FIGS. 13-16 . The application of force to the actuator members  798  and  800  is then interrupted. The application of force to the input end portion  806  of the plunger  776  is also interrupted. The apparatus  770  is then moved upward (as viewed in  FIG. 35 ) away from the suture retainer.  
         [0271]     Although the apparatus  770  has been disclosed herein in association with the suture retainer  772 , it is contemplated that the apparatus could be utilized to install suture retainers having a different construction. If the apparatus  770  is used to install a suture retainer having an outer side surface with a configuration which is different than the configuration of outer side surface of the suture retainer  772 , the configuration of the force application members  792  and  794  would be modified to correspond to the configuration of the suture retainer to be installed. For example, if the suture retainer had a flat outer side surface, the force application members  792  and  794  would be modified to have flat surfaces to engage the suture retainer. If the suture retainer had the spherical outer side surface of the suture retainer  50  ( FIG. 2 ), the force application members  792  and  794  would have configurations corresponding to the configuration of portions of a sphere.  
       Embodiment of the Invention Illustrated in FIG.  36   
       [0272]     In the embodiment of the invention illustrated in  FIG. 35 , an apparatus  770  for installing a suture retainer  772  is disclosed. In the embodiment of the invention illustrated in  FIG. 36 , a second apparatus for installing a suture retainer is disclosed. Since the embodiment of the invention illustrated in  FIG. 36  is similar to the embodiment of the invention illustrated in  FIG. 35 , similar terminology will be utilized to identify similar components.  
         [0273]     An apparatus or tool  870  for positioning a suture retainer  872  relative to body tissue  54  includes a base or housing  874 . A cylindrical plunger  876  is slidable in the housing  874 . The plunger  876  is connected with left and right force application or clamp members  880  and  882  by a pair of linkages  884 . Although only one of the linkages  884  has been shown in  FIG. 36 , it should be understood that there is a second linkage having the same construction as the linkage  884  connected with the plunger  876 .  
         [0274]     A biasing spring  888  extends around the plunger  876  and urges the plunger upward (as viewed in  FIG. 36 ). The force transmitted from the biasing spring  888  through the plunger  876  and linkages  884  urges the left and right force application members  880  and  882  into engagement with the suture retainer  872 . The force provided by the spring  888  is insufficient to cause significant deformation of the suture retainer  872 . However, the force provided by the spring  888  is sufficient to enable the force application members  880  and  882  to hold the suture retainer  872  during sliding of the suture retainer along the suture  52 .  
         [0275]     A transducer or load cell  892  is connected with the plunger  876  and provides an output signal, over a lead  894  to a display unit  896 . This output is indicative of the magnitude of the force transmitted through the plunger  876 . When a predetermined force has been applied by the force application members  880  and  882  against the suture retainer  872  for a predetermined minimum length of time, an indicator  898  is activated by the display unit  896 .  
         [0276]     The specific suture retainer  872  illustrated in  FIG. 36  has a one-piece tubular cylindrical construction. The suture  52  has left and right sections  66  and  68  which are wrapped around the suture retainer  872  in the same manner as in which the suture  52  is wrapped around the suture retainer  50  of  FIG. 2 . Thus, a loop  904  is formed in the left section  66  of the suture  52  and extends around a portion of the tubular cylindrical suture retainer  872 . Similarly, a loop  906  is formed in the right section  68  of the suture  52  and extends around a portion of the tubular cylindrical suture retainer  872 .  
         [0277]     In the embodiment of the invention illustrated in  FIG. 36 , a force distribution member or button  910  is provided at the upper side surface  98  of the body tissue  54 . The force transmission member or button  910  distributes the force applied by the suture retainer  872  to the body tissue  54  over a relatively large area on the body tissue. If desired, a second force distribution member could be provided between the suture and a lower side surface  108  of the body tissue  54 . Since the suture retainer  872  is effective to apply force to a relatively large area, the button  910  may be omitted if desired.  
         [0278]     When the suture retainer  872  is to be installed in the body tissue, the two sections  66  and  68  of the suture are sewn through the body tissue  54  and are then inserted into the suture retainer  872 . During insertion of the left and right sections  66  and  68  of the suture  52  into the suture retainer  872 , the loops  904  and  906  are formed in the two sections  66  and  68  of the suture.  
         [0279]     The plunger  876  is then manually moved downward in the housing  874  against the influence of the biasing spring  888  to move the force application members  880  and  882  apart. When the force application members  880  and  882  have been positioned adjacent to opposite sides of the suture retainer  872 , the downward force applied against the plunger  876  is released. This results in the biasing spring  888  moving the plunger  876  upward to actuate the linkages  884  to press the force application members  880  and  882  against opposite sides of the suture retainer  874 .  
         [0280]     The left and right sections  66  and  68  of the suture  52  are then tensioned. The apparatus or tool  870  is then moved along the left and right sections  66  and  68  of the suture  52  toward the body tissue. As this occurs, the loops  904  and  906  are displaced downwardly along the tensioned sections  66  and  68  of the suture  52  toward the body tissue. During downward displacement of the loops  904  and  906  toward the body tissue  54 , the left and right sections  66  and  68  of the suture  52  slide along surfaces on the suture retainer  872 .  
         [0281]     After the suture retainer  872  has been moved into engagement with the button or force distribution member  910 , the leading end of the suture retainer  872  is pressed against the button with a predetermined force. This force is transmitted through the plunger  876  and is measured by the transducer  892 . Once the suture retainer  872  has been pressed against the button or force distribution member  910  with a predetermined force, the plunger  876  is manually pulled upward relative to the housing  874 . This results in the transmission of force through the linkage  884  to the force applying members  880  and  882 .  
         [0282]     The force applying members  880  and  882  apply sufficient force to the suture retainer  872  to effect plastic deformation of the suture retainer. At this time, the suture retainer is at a temperature below the transition temperature of the biodegradable polymeric material of the suture retainer. Thus, the suture retainer is at a temperature which is the same as the temperature of the body tissue  54 . The plastic deformation of the suture retainer  872  results in cold flowing of the material of the suture retainer and gripping of the left and right sections  66  and  68  of the suture  52  in the manner previously explained in conjunction with the embodiments of the invention illustrated in  FIGS. 1-35 .  
         [0283]     It should be understood that the tool  870  may be used to install any of the suture retainers illustrated in  FIGS. 1-33 . Of course, the force application or clamp members  880  and  882  would be configured so as to grip the outer side surface of the specific suture retainer with which the tool is to be used.  
       CONCLUSION  
       [0284]     The present invention provides a new and improved method and apparatus for use in securing a suture  52  relative to body tissue  54 . A suture retainer  50  (( FIGS. 1-3 ) may be plastically deformed to grip the suture. The plastic deformation of the suture retainer  50  may include pressing the material of the suture retainer against the suture  52  by cold flowing material of the suture retainer. The plastic deformation of the material of the suture retainer  50  may be performed while transmitting a predetermined force from the suture retainer  50  to the body tissue  54 .  
         [0285]     The strength of a connection between the suture retainer  50  and the suture  52  may be increased by forming bends  72 ,  74 ,  76  and  78  in the suture  52  before deforming the material of the suture retainer  50 . As the suture retainer is moved along the first and second sections of the suture toward the body tissue  54 , the bends  72 ,  74 ,  76  and  78  are moved along the suture with the suture retainer. The bends  72 ,  74 ,  76 , and  78  may be formed by wrapping the suture  52  around a circular portion of the suture retainer ( FIGS. 9, 13 ,  17 , and  20 ), by moving the suture through one or more passages in the suture retainer ( FIGS. 2, 21 ,  23 ,  24 ,  25 ,  26 , and  29 ), by bending the suture around a member ( FIG. 6 ), and/or by deflecting a portion of the suture retainer through which the suture extends ( FIG. 32 ).  
         [0286]     The suture retainer  50  may be gripped with a tool  770  or  870  which is moved along the suture  52  to move the suture retainer toward the body tissue  54 . The tool  770  or  870  may be used to urge the suture retainer toward the body tissue with a predetermined minimum force. In addition, the tool  770  or  870  may be used to plastically deform the material of the suture retainer when the suture retainer has been moved to a desired position. The tool  770  or  870  may be used in association with any of the embodiments of the suture retainer illustrated in  FIGS. 1-33 .  
         [0287]     It should be understood that the specific and presently preferred embodiments of the invention illustrated herein are only examples of many different embodiments of the invention which are possible. In describing the presently preferred embodiments of the invention illustrated herein, similar terminology has been used to designate components which are similar in structure and function. The specific features of any one embodiment of the invention may be utilized in association with any of the other embodiments of the invention.