Suture anchor

[0002] This is a continuation of application Ser. No. 09/378,190 filed Aug. 20, 1999 (now U.S. Pat. No. 6,152,949). The aforementioned application Ser. No. 09/378,190 is itself a continuation of application Ser. No. 08/964,167 filed Nov. 4, 1997 (now U.S. Pat. No. 5,980,559). The aforementioned application Ser. No. 08/964,167 is itself a divisional of application Ser. No. 08/699,553 filed Aug. 19, 1996 (now U.S. Pat. No. 5,718,717). The benefit of the earlier filing dates of the aforementioned applications is hereby claimed.

[0003] The present invention relates to a new and improved suture anchor and more specifically to a suture anchor which is capable of expanding in a patient's body to enable the anchor to withstand relatively large pull-out forces.

[0004] Anchors are commonly utilized to retain sutures in a patient's body. The anchors have previously been formed of metal, such as stainless steel or titanium. In addition, anchors have been formed of biodegradable materials. These known anchors have relied upon mechanical interlocks between the body tissue and the anchor to retain the anchor in place against the influence of forces transmitted through the suture to the anchor. It has previously been suggested to construct anchors in the manner disclosed in U.S. Pat. Nos. 5,405,359; 5,403,348; 5,203,787; 5,046,513; and 5,041,129. In addition, an anchor formed of body tissue is disclosed in co-pending application Ser. No. 08/626,393 filed Mar. 29, 1996 filed by Peter M. Bonutti and entitled “Suture Anchor”.

[0005] The present invention relates to a new and improved suture anchor which absorbs body liquid. A suture extends from the anchor. The anchor and the suture are inserted into a patient's body. When the anchor is disposed in the patient's body, the anchor expands. The anchor expands by absorbing body liquid and/or by its own natural resilience. As the anchor expands, an improved interlock is obtained between the anchor and the body tissue to enable the anchor to resist relatively large tension forces transmitted through the suture.

[0006] The anchor may be formed of a material which absorbs body liquid. Alternatively, the anchor may contain cells which are expanded to absorb body liquid.

[0007] The anchor may have a leading end portion which forms an opening in an imperforate body surface. Alternatively, the anchor may be inserted into body tissue through an opening formed in the body tissue by a member other than the anchor. The configuration of the anchor may be changed while the anchor is in the body tissue.

[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 manner in which an anchor is inserted into a patient's body with a suture extending into the anchor;

[0010] FIG. 2 is a schematic illustration depicting the manner in which the anchor of FIG. 1 is pivoted in the patient's body;

[0011] FIG. 3 is a schematic illustration depicting the manner in which the patient's body tissue is secured with the anchor immediately after the anchor has been inserted into the patient's body;

[0012] FIG. 4 is a schematic illustration, generally similar to FIG. 3, illustrating the manner in which the anchor expands by absorbing body liquid after the anchor has been inserted into the patient's body;

[0013] FIG. 5 is a schematic illustration depicting another manner in which the anchor of FIG. 1 may be inserted into a patient's body;

[0014] FIG. 6 is a schematic illustration depicting the manner in which the anchor of FIG. 5 expands in the patient's body by absorbing body liquid;

[0015] FIG. 7 is a schematic illustration, generally similar to FIG. 1, illustrating the manner in which a second embodiment of the anchor may be inserted into a patient's body through an imperforate surface on body tissue;

[0016] FIG. 8 is a schematic pictorial illustration of a third embodiment of the anchor having a portion which absorbs body liquid and a portion which does not absorb body liquid and has projections to engage body tissue;

[0017] FIG. 9 is a schematic pictorial illustration of a fourth embodiment of the anchor having a core which absorbs body liquid and a casing formed of an elastic material which does not absorb body liquid;

[0018] FIG. 10 is a pictorial schematic illustration of a fifth embodiment of the anchor having an end portion with a suture receiving opening formed in material which does not absorb body liquid and is connected with a main portion which absorbs body liquid;

[0019] FIG. 11 is a schematic illustration of a an apparatus for inserting an anchor having cells which are collapsed before the anchor is moved into a patient's body;

[0020] FIG. 12 is a schematic illustration of another apparatus for inserting the anchor of FIG. 11 into body tissue;

[0021] FIG. 13 is a schematic illustration of the manner in which the configuration of an anchor is changed while the anchor is in the patient's body tissue; and

[0022] FIG. 14 is a schematic illustration of another manner in which the configuration of an anchor is changed while the anchor is in a patient's body tissue.

[0023] Suture anchors have previously been utilized to retain sutures in either hard or soft tissue in a human patient's body. The suture anchors have previously been formed of metal, biodegradable materials, and other materials. These known suture anchors have been retained in the patient's body by changing the orientation of the anchor relative to the patient's body once it has been inserted into the patient's body. Alternatively, known anchors have been retained in the patient's body by a mechanical interlock formed with the material of the patient's body by barbs or other projections.

[0024] In accordance with one of the features of the present invention, sutures may be retained in a patient's body by anchors which are at least partially formed of material which absorbs body liquid when exposed to the body liquid. The material expands as it absorbs the liquid in the patient's body. As the anchor expands, an improved interlock is formed between the anchor and body tissue of the patient's body. The improved interlock enables relatively large forces to be transmitted through a suture to the anchor.

[0025] In accordance with another of the features of the present invention, sutures may be retained in a patient's body by anchors which are formed of material which expands under the influence of its own natural resilience. As the material expands, cells are expanded from a collapsed condition. As the cells expand, the anchor absorbs body liquid by at least partially filling the cells with body liquid. As the anchor expands, an improved interlock is formed between the anchor and tissue of the patient's body. If desired, the material which forms the cells could also absorb body liquid.

[0026] In accordance with another feature of the invention, the anchor could be inserted into a patient's body through an imperforate surface on body tissue. This may be done by forming an opening in the body tissue with a leading end portion of the anchor. Alternatively, the opening could be formed by one or more members other than the anchor. Once the anchor has entered the patient's body the configuration of the anchor may be changed under the combined influence of force transmitted to the anchor through the suture and force applied against the outer surface of the anchor by body tissue.

[0027] A suture anchor 20 (FIG. 1) is formed of a material which absorbs body liquid when the anchor is exposed to body liquid. As the material of the anchor 20 absorbs body liquid, the anchor expands from the initial volume of FIGS. 1-3 to the expanded volume of FIG. 4. As the material of the anchor 20 absorbs body liquid and expands, the volume of the anchor increases and an improved mechanical interlock is formed between the anchor and body tissue in which the anchor has been inserted. The improved interlock enables the anchor 20 to resist large tension forces in a suture 32 without pulling out of body tissue 22.

[0028] It is contemplated that the anchor 20 could be completely formed of material which absorbs body liquid. Alternatively, the anchor could be partially formed of material which absorbs body liquid and partially formed of material which does not absorb body liquid. The material which does not absorb body liquid may be provided with projections which are forced into the body upon expansion of the material which absorbs body liquid. This would result in at least two different interlocks being obtained between the anchor and the body tissue, that is, an interlock due to expansion of the material which absorbs body liquid and an interlock due to engagement of projections on the material which does not absorb body liquid with the body tissue.

[0029] The suture anchor 20 is entirely formed of material which absorbs body liquid. In one specific instance, the suture anchor 20 was formed of a polymeric material which absorbs body liquid. The polymeric material may be either a copolymer or a dipolymer. The polymeric material may be hydrophilic. The polymeric material may be cellulose, petroylglutamic acid, high purity carboxymethylcellulose, a collagen, or polylactide. It is believed that a ceramic as found in hydroxyapatite composites with polyethylene, polylactide or polyhydroxybutyrate may be utilized to form the anchor 20. Of course, the suture anchor 20 could be formed of other known materials which absorb body liquid.

[0030] It is theorized that the hydrophilic material forming the anchor 20 attracts body liquid under the influence of molecular attraction and establishes molecular linkages with the body liquid. The material forming the anchor 20 is body liquid permeable. The body liquid enters minute cavities in the porous material forming the anchor 20 under the influence of capillary action. The attractive forces between molecules of the body liquid and molecules of the material forming the anchor 20 holds the body liquid in the minute cavities in the material forming the anchor.

[0031] In the embodiment of the invention illustrated in FIGS. 1-3, the suture anchor 20 has a tubular cylindrical configuration. The suture anchor 20 has a tubular wall 24 formed of material which absorbs body liquid. The tubular wall 24 has a cylindrical outer side surface 26 which is coaxial with a cylindrical inner side surface 28. The cylindrical inner side surface 28 forms a cylindrical passage 30 which extends axially through the center of the suture anchor 20.

[0032] The wall 24 of the suture anchor 20 is formed as one piece of a porous hydrophilic polymer which absorbs body liquid. Although it is preferred to form the anchor 20 with a cylindrical configuration, the anchor may be shaped or ground to any one of many different axially tapering or flaring configurations, such as those disclosed in U.S. Pat. No. 5,403,348. It is believed that it may be preferred to form the anchor 20 with either a cylindrical configuration or a polygonal configuration.

[0033] Although it is contemplated that the tubular cylindrical suture anchor 20 could be of many different sizes, it is believed that the suture anchor may preferably have a length or axial extent of between 2 and 4 millimeters. The cylindrical outer side surface 26 of the suture anchor 20 may have a diameter of between 1 and 2 millimeters. The cylindrical inner side surface 28 of the passage 30 in the anchor 20 may have a diameter of ½ to 1 millimeter. Of course, the suture anchor 20 could be formed with many different dimensions and/or shapes if desired.

[0034] A suture 32 is inserted into the passage 30 in the suture anchor 20. The suture 32 includes a portion or leg 34 which extends away from a flat annular trailing end surface 36 of the anchor 20. In addition, the suture 32 has a second portion or leg 38 which extends across a flat annular leading end surface 40 of the anchor 20. The leg 38 of the suture 32 extends along the cylindrical outer side surface 26 of the anchor 20 to a location adjacent to and spaced from the leg portion 34 of the suture 32. A relatively short portion 44 of the suture 32 interconnects the leg portions 34 and 38 and is disposed in the passage 30 in the suture anchor 20.

[0035] An inserter assembly 60 is used to position the suture anchor 20 and a portion of the suture 32 in a patient's body tissue 22. The inserter assembly 60 includes a cylindrical tubular outer sleeve 66 having a cylindrical central passage 68 in which the anchor 20 is disposed. The inserter 60 also includes a cylindrical tubular inner sleeve 72 which is telescopically received in the outer sleeve 66. The tubular inner sleeve 72 has a conical tapered leading end portion 74 which engages an annular trailing end surface 36 of the anchor 20.

[0036] The leg or portion 34 of the suture 32 extends through a cylindrical passage 76 in the inner sleeve 72. The leg or portion 38 of the suture 32 extends through the central passage 68 in the outer sleeve 66 along a path which extends between the inner and outer sleeves. The leg or portion 38 of the suture 32 could extend along the outside of the outer sleeve 66. If desired, one of the legs or portions 34 or 38 of the suture could be omitted. If this was done, the suture 32 could be tied or otherwise secured to the anchor 20.

[0037] It is contemplated that the anchor 20 may be inserted into a human patient's body at many different locations. The anchor 20 may be inserted into either hard or soft tissue. In the situation illustrated schematically in FIG. 1, the anchor 20 is being inserted into bone tissue 22 in a patient's body. A cylindrical recess 80 is formed in the bone tissue 22 of the patient's body by drilling or other methods. The recess 80 extends through a hard compact outer layer 82 of the patient's bone tissue 22 into the relatively porous inner or cancellous tissue 84.

[0038] To insert the anchor 20 in the patient's body tissue 22, the cylindrical inner sleeve 72 is moved axially downward (as viewed in FIG. 1) to apply force against a relatively small area on the annular trailing end surface 36 of the anchor 20. Once the anchor 20 has been pushed into the recess 80 by axial movement of the inner sleeve 72 relative to the outer sleeve 66, the leg 38 of the suture 32 is tensioned to apply force against an annular leading end surface 40 of the anchor 20. At the same time, the bevelled leading end 74 of the inner sleeve 72 is pressed against the trailing end surface 36 of the anchor.

[0039] This results in the application of a counterclockwise (as viewed in FIGS. 1 and 2) torque to the anchor 20. This torque causes the anchor 20 to pivot through the orientation shown in FIG. 2 to the orientation shown in FIG. 3. Once the anchor 20 has been pivoted to the orientation shown in FIG. 3, by tensioning the suture 32 and applying force against the anchor with the leading end portion 74 of the inner sleeve 72, the anchor 20 engages the hard compact outer layer 82 of the patient's bone tissue to hold the anchor in the recess 80. Thus, a solid initial interlock is obtained between the anchor 20 and body tissue 22.

[0040] The suture 32 is then tensioned to secure a member, such as body tissue 90, in place. The member or body tissue 90 may be soft tissue, or a ligament, or a tendon, or other body tissue. If desired, the suture 32 may be used to secure other members, such as an implant or splint, in place relative to the patient's body tissue 22. The suture is tensioned to transmit force between the anchor 20 and a member to be held in place.

[0041] One specific known inserter assembly 60 and method of inserting a suture anchor 20 into a patient's body tissue has been illustrated in FIGS. 1-3. This specific inserter assembly and the method of inserting the anchor 20 are the same as is disclosed in U.S. Pat. No. 5,403,348 issued Apr. 4, 1995 and entitled “Suture Anchor”. However, it is contemplated that many different known types of inserter assemblies could be utilized to install the suture anchor 20 with many different methods in a patient's body tissue. For example, the inserter assembly and method disclosed in U.S. Pat. No. 5,464,426 issued Nov. 7, 1995 and entitled “Method of Closing Discontinuity in Tissue” could be utilized if desired. Of course, other known apparatus and methods could also be utilized if desired.

[0042] In accordance with a feature of the invention, the suture anchor 20 absorbs body liquid and expands once the suture anchor has been inserted into the body tissue 22. The expansion of the suture anchor 20 improves the initial interlock between the anchor and body tissue 22. The initial interlock between the anchor 20 and body tissue 22 is obtained by pivoting the anchor in the body tissue to the orientation shown in FIG. 3. The improved interlock is obtained by expanding the anchor 20, as shown in FIG. 4. The improved interlock allows relatively large tension forces to be transmitted through the suture 32 between the anchor 20 and a member to be held in place by the suture.

[0043] The suture anchor 20 expands in all directions, from the initial size illustrated in FIG. 3 to a relatively large expanded size illustrated in FIG. 4, shortly after the suture anchor has been inserted into the body tissue 22. After the suture anchor 20 has been inserted into the body tissue 22, the suture anchor is exposed to body liquids, indicated schematically at 98 in FIG. 4. The body liquids 98 are drawn into the suture anchor 20 due to the affinity of the polymeric material forming the suture anchor 20 for body liquids.

[0044] As the body liquids 98 are drawn into the suture anchor 20, the anchor expands in a substantially uniform manner in all directions. Thus, the anchor 20 swells both radially and axially. Substantially uniform expansion of the entire outer side surface area of the suture anchor 20 occurs as body liquids 98 are absorbed by the anchor. The extent of expansion of the suture anchor 20 will depend upon the specific characteristics of the material from which the suture anchor is formed and may vary between 10 and 50 percent by volume. Of course, the extent of expansion of the anchor 20 will be a function of the force applied against the outer side surface of the anchor by the body tissue 22.

[0045] As the suture anchor 20 swells, the size of the anchor 20 increases. As the size of the anchor 20 increases, the outer side surface of the anchor presses both axially and radially outward against the body tissue 22. As the anchor 20 expands and presses against the body tissue, the body tissue is displaced by the anchor. Thus, the outer side surface of the anchor 20 applies force against the body tissue 22 and moves the body tissue to make room for the anchor as the anchor expands. If the anchor 20 encounters a localized area of high resistance to expansion in the body tissue, the anchor will expand around the localized area and may even shift in the body tissue 22.

[0046] The expansion of the anchor 20 as it absorbs the body liquids 98 results in an increasing mechanical interlocking action between the anchor 20 and the body tissue 22. There is an initial mechanical interlock between the anchor 20 and the body tissue 22 when the anchor has its original or initial size (FIG. 3). As body liquids 98 are absorbed by the suture anchor 20 and the volume of the anchor increases, the anchor expands to improve the mechanical interlock between the anchor and the body tissue 22. The improved interlock between the anchor 20 and body tissue 22 allows relatively large tension forces to be transmitted through the suture 32 without pulling the anchor out of the body tissue.

[0047] In the embodiment of the invention illustrated in FIGS. 1-4, the anchor 20 was pivoted from the orientation shown in FIG. 1 through the orientation shown in FIG. 2 to the orientation shown in FIG. 3 to obtain an initial mechanical interlock between the anchor and body tissue 22. In the embodiment of the invention illustrated in FIGS. 5 and 6, the anchor is not pivoted from its initial orientation to obtain an initial mechanical interlock. The anchor is merely positioned in the body tissue and expanded in all directions by absorbing body liquid. The expansion of the anchor results in the formation of an interlock between the anchor and the body tissue. Since the embodiment of the invention illustrated in FIGS. 5 and 6 is generally similar to the embodiment of the invention illustrated in FIGS. 1-4, similar numerals will be utilized to designate similar components, the suffix letter “a” being associated with the numerals of FIGS. 5 and 6 in order to avoid confusion.

[0048] The suture anchor 20ahas the same construction and is formed of the same hydrophilic polymeric material as the suture anchor 20 of FIGS. 1-3. The suture anchor 20a(FIG. 5) has a cylindrical tubular configuration. The suture anchor 20ahas a cylindrical outer side surface 26a. A cylindrical central passage 30aextends through the suture anchor 20abetween opposite annular end surfaces 36aand 40aof the suture anchor 20a.

[0049] A suture 32ahas a leg 34awhich extends through a passage 76aformed in an inner sleeve 72a. A second leg 38aof the suture 32aextends through a central passage 68aand a tubular outer sleeve 66a. The leg 38aof the suture 32aextends between a cylindrical inner side surface 68aof the inner sleeve 72aand a cylindrical inner side surface of the outer sleeve 66a.

[0050] It is contemplated that the anchor 20amay be inserted into a patient's body at many different locations. The anchor 20amay be inserted into either hard or soft tissue. In the situation illustrated schematically in FIG. 5, the anchor is being inserted into bone tissue 22ain a patient's body with the inserter assembly 60a. A recess 80ais formed in the bone tissue 20aof the human patient's body by drilling or other methods. The cylindrical recess 80aextends through the hard compact outer layer 82aof the patient's bone tissue 20ainto the relatively porous inner or cancellous tissue 84a.

[0051] To insert the anchor 20ain the patient's body tissue 22a, the inner sleeve 72ais moved axially downward (as viewed in FIG. 5) to apply force against the trailing end surface 36aof the anchor 20a. In this embodiment of the inserter assembly 60a, the inner sleeve 72ahas a cylindrical leading end portion 74awhich applies a substantially uniform force over substantially the entire flat annular trailing end surface 36aof the anchor 20a. Therefore, the anchor 20ais not pivoted but is merely moved straight into the recess 80a.

[0052] Once the anchor 20ahas been positioned in the recess 80a, the anchor absorbs body liquid 98aand increases in volume as the liquid is absorbed. This results in the anchor expanding in all directions from the initial size of FIG. 5 to a relatively large expanded size illustrated in FIG. 6. As the anchor 20aexpands, its size increases by 10 to 50 percent by volume.

[0053] The anchor 20ais porous and is formed of a hydrophilic material. The body liquid 98ais drawn into openings in the porous material of the anchor 20aby the affinity of the porous material forming the anchor for the body liquid. The attractive forces between the material forming the anchor 20aand the body liquid holds the body liquid in the anchor.

[0054] As the anchor 20aexpands from the initial size, the outer surfaces on the anchor press radially and axially against the body tissue 22a. Substantially uniform expansion of the anchor 20aforms a secure mechanical interlock with the body tissue. This interlock enables tension forces to be transmitted through the suture 32abetween the anchor 20aand a member, such as the body tissue 90a.

[0055] As the anchor 20aexpands radially outward, the cancellous tissue 84ais compressed and the size of the portion of the recess 80ain the cancellous tissue 84ais increased. As this happens, the diameter of the cylindrical anchor 20aincreases from a diameter which is just slightly less than the size of the portion of the recess 80awhich extends through the hard compact outer layer 82aof the bone tissue 22ato a diameter which is greater than the diameter of the portion of the recess 80aextending through the hard compact outer layer 82aof bone tissue. This results in the anchor 20abeing locked in place in the body tissue 22a.

[0056] The suture 32acan then be used to secure a member 90ain place in the manner illustrated schematically in FIG. 6. The member 90amay be soft body tissue, or a ligament, or a tendon, or other body tissue. If desired, the suture 32amay be used to secure an implant or splint in place relative to the patient's body 22a. The interlock between the anchor 20aand body tissue 22aenables substantial tension force to be transmitted through the suture 32awithout pulling the anchor out of the body tissue.

[0057] The expansion of the anchor 20ahas been schematically illustrated in FIG. 6 as being uniform in all directions. This will be the case when the body tissue 22aapplies uniform forces against all sides of the anchor 20a. However, the body tissue 22amay provide nonuniform resistance to expansion of the anchor 20a. When this occurs, the anchor 20amay shift in the body tissue 22aunder the influence of forces applied against the body tissue as the anchor expands. In addition or alternatively, the anchor 20amay expand in a nonuniform manner.

[0058] In the embodiment of the invention illustrated in FIGS. 1-4, the anchor 20 has a generally cylindrical configuration and is formed entirely of a hydrophilic polymeric material which absorbs body liquid. The anchor illustrated in FIGS. 1-4, due to its relatively blunt leading end portion, is particularly well adapted for positioning in preformed recesses in body tissue. In the embodiment of the anchor illustrated in FIG. 7, the anchor has a sharp or pointed leading end portion to facilitate forming an opening in imperforate body tissue. Since the embodiment of the invention illustrated in FIG. 7 is generally similar to the embodiment of the invention illustrated in FIGS. 1-4, similar numerals will be utilized to designate similar components, the suffix letter “b” being associated with the numerals of FIG. 7 to avoid confusion.

[0059] The tubular cylindrical suture anchor 20bhas a generally cylindrical outer side surface 26bwhich is coaxial with a cylindrical inner side surface 28b. The cylindrical inner side surface 28bforms a portion of a passage 30bwhich extends through the anchor 20b. In addition to the main portion of the passage 30bformed by the cylindrical side surface 28b, a second cylindrical side surface 110 has a central axis which extends perpendicular to the central axis of the cylindrical side surface 28b. The cylindrical side surface 110 intersects the cylindrical side surface 28band extends radially outward from the cylindrical side surface 28b. The cylindrical side surfaces 28band 110 cooperate to form the passage 30bwith a generally L-shaped configuration.

[0060] A suture 32bis inserted into the passage 30bin the suture anchor 20b. The suture 32bincludes a portion or leg 34bwhich extends away from a flat annular trailing end surface 36bof the anchor 20b. In addition, the suture 32bhas a second portion or leg 38bwhich extends along the cylindrical outer side surface 26bof the anchor 20band along the cylindrical inner side surface 68bof the outer sleeve 66b. A relatively short portion 44bof the suture 32binterconnects the leg portions 34band 38band is disposed in the passage 30bin the suture anchor 20b.

[0061] An inserter assembly 60bis used to position the suture anchor 20band a portion of the suture 32bin a patient's body tissue 22b. The inserter assembly 60bincludes a generally cylindrical tubular outer sleeve 66bhaving a central passage 68bin which the anchor 20bis disposed. The inserter 60balso includes a tubular inner sleeve 72bwhich is telescopically received in the outer sleeve 66b. The tubular inner sleeve 72bhas a conical tapered leading end portion 74bwhich engages the trailing end surface 36bof the anchor 20b.

[0062] In accordance with a feature of the embodiment of the invention illustrated in FIG. 7, the anchor 20bhas a leading end portion 112 with a generally conical configuration. The leading end portion 112 of the anchor 20bis adapted to form an opening in an imperforate outer side surface 114 of the patient's body tissue 22b. In addition, the leading end portion 112 of the anchor 20bfacilitates moving the anchor into the body tissue 22bunder the influence of force applied against the trailing end surface 36bof the anchor 20bby the tubular inner sleeve 72b. The conical leading end portion 112 of the anchor 20bis formed by a conical layer of a relatively hard polymeric material. The polymeric material forming the leading end portion 112 may be biodegradable if desired.

[0063] In addition, the anchor 20bhas a cylindrical body portion or wall 116 which is disposed in a coaxial relationship with the leading end portion 112. The cylindrical body portion 116 is formed of a hydrophilic polymeric material which absorbs body liquid when exposed to the body liquid. The cylindrical body portion 116 is formed of the same material as the anchor 20 of FIGS. 1-4. As the body portion 116 of the anchor 20babsorbs body liquid, the body portion of the anchor expands radially and axially to interlock with the body tissue 22b. The leading end portion 112 is formed of a rigid polymeric material which does not absorb body liquid.

[0064] The leading end portion 74bof the tubular inner sleeve 72bis tapered so that it applies force against the trailing end surface 36bof the anchor 20bat a relatively small area on the trailing end surface. The concentrated application of force to the trailing end surface 36bof the anchor 20bfacilitates pivoting movement of the anchor in the body tissue 22bupon tensioning of the leg 38bof the suture 32b.

[0065] Assuming the anchor 20bis to be moved into body tissue 22bdisposed beneath a layer 120 of skin, force is applied against the tubular inner sleeve 72bto force the pointed leading end portion 112 of the anchor against the imperforate outer side surface 114 of the skin 120. This force causes the anchor 20bto pierce the skin 120 and enter soft body tissue 122 disposed beneath the skin. Once the anchor 20bhas been moved completely beneath the skin 120 into the soft body tissue 122, the leg 38bof the suture 32bis tensioned. This results in the application of torque to the anchor 20btending to rotate or pivot the anchor in a counterclockwise direction from the orientation shown in FIG. 7 to a generally horizontal orientation, corresponding to the orientation of the anchor illustrated in FIG. 3. At this time, the longitudinal central axis of the anchor will be generally parallel to the skin 120.

[0066] Once the anchor 20bhas been moved into the body tissue 122 and pivoted in the manner previously explained, the body portion 116 of the anchor will absorb body liquid, such as blood or other fluids. As the hydrophilic body portion 116 of the anchor 20babsorbs body liquids, the body portion expands in all directions and presses against the body tissue 122. As the anchor expands, body tissue is displaced and the mechanical interlock with the anchor 20bis enhanced.

[0067] Thus, the anchor 20bis mechanically interlocked with the body tissue 122 by both pivotal movement of the anchor to a sidewise orientation and expansion of the anchor as it absorbs body liquids. The improved interlock obtained by expanding the anchor 20benables relatively large tension forces to be transmitted between a member (not shown) and the anchor 20bthrough the suture 32b.

[0068] In the embodiment of the anchor illustrated in FIGS. 1-4, the anchor is formed entirely of material which absorbs body liquid when it is exposed to the body liquid. In the embodiment of the anchor illustrated in FIG. 8, a portion of the anchor is formed of material which absorbs body liquid and another portion of the anchor is formed of material which does not absorb body liquid. The material which does not absorb body liquid has projections which engage body tissue to enhance an interlock between the anchor and the body tissue. Since the embodiment of the invention illustrated in FIG. 8 is generally similar to the embodiment of the invention illustrated in FIGS. 1-4, similar numerals will be utilized to designate similar components, the suffix letter “c” being associated with the numerals of FIG. 8 in order to avoid confusion.

[0069] An anchor 20c(FIG. 8) has a tubular cylindrical configuration. A suture (not shown) extends through a central passage 30cin the anchor 20cin the same manner as illustrated in FIG. 1 for the anchor 20.

[0070] In accordance with a feature of this embodiment of the invention, the anchor 20c(FIG. 8) has a body portion 116cwhich is formed of a hydrophilic polymeric material which absorbs body liquid when exposed to the body liquid. In addition, the anchor 20cincludes a plurality of identical retaining portions 130, 132 and 134. The retaining portions 130, 132 and 134 are formed of a relatively hard polymeric material which does not absorb body liquid. The retaining portions 130, 132 and 134 may be biodegradable if desired.

[0071] In the illustrated embodiment of the invention, the retaining portions 130, 132 and 134 and a plurality of ribs or projections 138 which extend outward from the retaining portion. When the anchor 20cis positioned in body tissue in the manner previously explained in conjunction with the embodiments of the invention illustrated in FIGS. 1-4, the body portion 116cabsorbs body liquid. When this occurs, the body portion 116cof the anchor 20cexpands radially and axially outward to enhance the mechanical interlock with the body tissue.

[0072] As the body portion 116cof the anchor 20cexpands, the retaining portions 130, 132 and 134 are moved radially outward away from the central axis of the anchor 20c. This presses the ribs 138 on the retaining portions 130, 132 and 134 into the body tissue to further enhance the mechanical interlock between the anchor and the body tissue. Although the ribs 138 have been shown in FIG. 8 as having a generally arcuate configuration and a generally smooth outer side surface, it is contemplated that the ribs could have barbs or other projections which would impale the body tissue as the body portion 116cof the anchor 20cabsorbs body liquid and expands. Of course, this would further enhance the mechanical interlock between the anchor 20cand the body tissue.

[0073] In the embodiment of the anchor 20cillustrated in FIG. 8, the anchor has a generally flat annular leading end portion. However, it is contemplated that the anchor 20ccould be provided with a conical leading end portion, similar to the conical leading end portion 112 on the anchor 20bof FIG. 7. If the anchor 20cwere to be provided with a conical leading end portion, it is contemplated that the retaining portions 130, 132 and 134 could be extended in an axial direction to form the conical leading end portion as three separate segments. As the body portion 116cof the anchor 20cabsorbs body liquid and expands, the retaining portions 130, 132 and 134 would move radially outward away from each other and the leading end portion of the anchor would expand.

[0074] A relatively strong interlock is obtained between the anchor 20cand body tissue. This interlock is obtained by changing the orientation of the anchor 20crelative to the body tissue, in the manner illustrated for the anchor 20 in FIG. 2. In addition, the interlock is obtained by expansion of the anchor 20cas the body portion 116cabsorbs body liquid. The interlock is also obtained by engagement of the ribs 138 with body tissue. The result is a strong interlock which enables the anchor 20cto resist very large tension forces transmitted to the anchor through a suture.

[0075] In the embodiment of the anchor 20 illustrated in FIGS. 1-4, the anchor is formed entirely of material which expands when it is exposed to body liquid. In the embodiment of the invention illustrated in FIG. 9, the anchor is formed by a core of material which expands upon being exposed to body liquid and an elastic jacket which encloses the core. Since the embodiment of the invention illustrated in FIG. 9 is generally similar to the embodiment of the invention illustrated in FIGS. 1-4, similar numerals will be utilized to designate similar components, the suffix letter “d” being associated with the numerals of FIG. 9 in order to avoid confusion.

[0076] An anchor 20d(FIG. 9) has a cylindrical configuration. The anchor 20dincludes a cylindrical core 144 which is enclosed by a tubular cylindrical jacket 146. A passage 30dextends through both the core 144 and the jacket 146. The passage 30dextends diametrically through the core 144 and the jacket 146 and has a cylindrical configuration. A suture (not shown) is positioned in the passage 30d. The suture may be tied off at one end of the passage or may extend through the passage so that legs of the suture extend along opposite sides of the jacket 146.

[0077] The jacket 146 is provided with a plurality of circular openings 150 which extend through the jacket. The openings 150 enable body liquid to pass through the jacket into the core 144. The jacket 146 is formed of an elastic polymeric material which is easily stretched. The core 144 is formed of a material which absorbs body liquid upon being exposed to the body liquid. In one specific embodiment of the suture anchor 20d, the core 144 was formed of a hydrophilic polymeric material which is the same as the material forming the anchor 20 of FIGS. 1-4.

[0078] When the anchor 20dis inserted into body tissue, in the manner illustrated schematically in either FIG. 1-3 or 5 and 6, the entire anchor 20dis exposed to body liquid. The body liquid passes through the openings 150 and is absorbed by the core 144. As the core 144 absorbs body liquid, the core expands and stretches the jacket 146.

[0079] Although the anchor 20dhas been shown as having a generally cylindrical configuration with flat annular end surfaces, it is contemplated that the anchor could be provided with a conical leading end portion, similar to the conical leading end portion 112 of the anchor 20bof FIG. 7. The conical leading end portion could be formed either as a portion of the jacket 46 or separately from the jacket. It is believed that it may be preferred to form a conical leading end portion for the anchor 20dseparately from the jacket 146 to enable the leading end portion to be formed of a hard material which is not readily stretched and which is capable of piercing an imperforate surface of body tissue.

[0080] In the illustrated embodiment of the invention, the jacket 146 is formed of a material which is resiliently stretched when the core 144 absorbs body liquid and expands. It is contemplated that the size of the jacket 146 could be increased in other ways to accommodate expansion of the core. For example, releasable tucks could be formed in the jacket. Upon expansion of the core, stitches or other devices holding the tucks would be released under the influence of force applied against the jacket by the core.

[0081] The anchors illustrated in FIGS. 1-9 all have passages through which the suture extends. In the embodiment of the invention illustrated in FIG. 10, the anchor has an eyelet through which the suture extends. Since the embodiment of the invention illustrated in FIG. 10 is generally similar to the embodiment of the invention illustrated in FIGS. 1-9, similar numerals will be utilized to designate similar components, the suffix letter “e” being associated with the embodiment of the invention illustrated in FIG. 10 to avoid confusion.

[0082] An anchor 20ehas a solid cylindrical body portion 116e. The body portion 116eof the anchor 20eis formed of a hydrophilic polymeric material which absorbs body liquid when exposed to the body liquid. The material forming the body portion of the anchor 20eis the same as the material forming the anchor 20 of FIGS. 1-4. Upon absorbing body liquid, a portion 116eof the anchor 20eexpands.

[0083] In accordance with a feature of the embodiment of the invention illustrated in FIG. 10, the anchor 20eis provided with a trailing end portion 160 which is connected with a suture. The trailing end portion 160 of the anchor 20ehas a circular wall 162 which is fixedly connected with the body portion 116eof the anchor 20e. A passage 30eis formed in a projection 164 which extends axially outward from the end wall 162. The passage 30ereceives a suture. The suture may be tied off on the projection 164 or may extend through the projection and have a pair of legs, corresponding to the legs 34 and 38 of the suture 32 of FIG. 1.

[0084] When the anchor 20eis inserted into body tissue, using an inserter assembly similar to the inserter assembly 60 of FIGS. 1 and 2, the body portion 116eis exposed to body liquid. This results in the body portion 116eof the anchor 20eexpanding radially and axially outward from the trailing end portion 160 to form a mechanical interlock with the body tissue.

[0085] In the embodiments of the invention illustrated in FIGS. 1-10, at least portions of the anchors are formed of a hydrophilic polymeric material which absorbs body liquid. In the embodiment of the invention illustrated in FIG. 11, the anchor is formed of cellular material which absorbs body liquid. Since the embodiment of the invention illustrated in FIG. 11 is generally similar to the embodiments of the invention illustrated in FIGS. 1-10, similar numerals will be utilized to designate similar components, the suffix letter “f” being associated with the numerals of FIG. 11 to avoid confusion.

[0086] A suture anchor 20fhas a tubular cylindrical configuration when the anchor is in an unrestrained condition. When the suture anchor 20fis in an unrestrained condition, the anchor has a tubular wall 24fwhich has a cylindrical outer side surface 26fwhich is coaxial with a cylindrical inner side surface 28fof the anchor. The cylindrical inner side surface 28fforms a passage 30fwhich extends axially through the center of the suture anchor 20fwhen the anchor is in an unrestrained condition.

[0087] The wall 24fof the suture anchor 20fis formed as one piece of resilient material containing a large number of cells which are expandable to absorb body liquid. The cellular material which forms the suture anchor 20fmay be a hydrophilic polymeric cellular material which absorbs body liquid. Although it is preferred to form the anchor 20fwith a cylindrical configuration, the anchor may be shaped to any one of many different axially tapering or flaring configurations or may have a polygonal configuration.

[0088] A suture 32fis inserted into the passage 30fin the suture anchor 20f. The suture 32fincludes a leg portion 34fwhich extends away from a flat annular trailing end surface 36fof the anchor 20f. In addition, the suture 32fhas a second portion or leg 38fwhich extends across a flat annular leading end surface 40fof the anchor 20f. The leg 38fof the suture 32fextends along the cylindrical outer side surface 26f. A relatively short portion 44fof the suture 32finterconnects the leg portion 34fand 38fand is disposed in the passage 30fin the anchor 20f.

[0089] An inserter assembly 60fis used to position the anchor 20fand a portion of the suture 32fin a patient's body tissue 22f. The inserter assembly 60fincludes a cylindrical tubular outer sleeve 66fhaving a cylindrical passage 68fin which the anchor 20fis disposed. The inserter 60falso includes a cylindrical tubular inner sleeve 72fwhich is telescopically received in the outer sleeve 66f. The tubular inner sleeve 72fhas a cylindrical leading end portion 74fwhich engages the trailing end surface 36fof the anchor 20f.

[0090] The leading end portion 74fof the tubular inner sleeve 72fhas an end wall 168 with a flat end surface which abuttingly engages the flat annular trailing end surface 36fon the anchor 20f. The two legs 34fand 36fof the suture 32fextend through a central opening formed in the end wall 168 at the leading end portion 74fof the inner sleeve 72f. The legs 34fand 38fof the suture 32fextend through the tubular inner sleeve 72fto a location remote from the inserter assembly 60f. If desired, one of the legs 34for 38fof the suture could be omitted. If this was done, the suture 32fcould be tied or otherwise secured to the anchor 20f.

[0091] It is contemplated that the anchor 20fmay be inserted into a human patient's body at many different locations. The anchor 20fmay be inserted into either hard or soft tissue. In the situation illustrated schematically in FIG. 11, the anchor 20fis being inserted into soft body tissue in a patient's body.

[0092] To facilitate insertion of the anchor 20finto soft body tissue, a leading end portion 170 of the outer sleeve 60fhas an axially tapered or pointed configuration. The pointed configuration of the leading end portion 170 of the outer sleeve 60fenables the leading end portion of the outer sleeve to form an opening in an imperforate outer side surface 114fof the patient's body tissue 22f. In addition, the pointed leading end portion 170 of the outer sleeve 60ffacilitates moving the outer sleeve 60finto the body tissue 22funder the influence of force manually applied against an outer end portion of the outer sleeve 60f.

[0093] To insert the anchor 20finto the patient's body tissue 22f, the pointed leading end portion 170 of the outer sleeve 66fis pressed against the imperforate outer side surface 114fof skin or other tissue 120f. The pointed leading end portion of the outer sleeve 66fpierces the imperforate outer surface 114fof the skin 120fand enters soft body tissue 122fdisposed beneath the skin. The outer sleeve 66fis forced into the soft body tissue 22ffor a desired distance corresponding to the distance which the suture anchor 20fis to be inserted into the body tissue.

[0094] The inner sleeve 72fis then pressed downward (as viewed in FIG. 11) to move the suture anchor 20fto the leading end portion 170 of the outer tubular member 66f. The inner side surface 68fof the tubular outer member 66fapplies force against the outer side surface 26fof the anchor 20fto maintain the anchor in the compressed condition shown in FIG. 11. The outer tubular member 66fis then moved axially upward (as viewed in FIG. 11) relative to the stationary inner tubular member 72f. This results in the anchor 20fbeing ejected from the outer tubular member 66finto the body tissue 22f. Once the anchor 20fhas moved from the outer sleeve 66finto the body tissue 22f, both the inner and outer sleeves 66fand 72fare withdrawn from the body tissue.

[0095] If desired, a pointed member, such as a trocar, could be inserted through the outer sleeve 66fto pierce the surface 114fand body tissue 22f. If this was done, the inner sleeve 72fand anchor 20fwould be removed from the outer sleeve 66fto provide room for the pointed member. After the body tissue has been pierced by the pointed member, the pointed member would be withdrawn from the outer sleeve 66fand the inner sleeve 72fand compressed anchor 20finserted into the outer sleeve.

[0096] In accordance with a feature of the present invention, the anchor 20fis formed of a resilient cellular material. Prior to insertion of the anchor 20finto the outer sleeve 66f, the cellular material of the anchor 20fis resiliently compressed from a relatively large unrestrained size to a compacted size illustrated in FIG. 11. The unrestrained size of the suture anchor 20fmay be 2 to 20 times as large as the size illustrated in FIG. 11.

[0097] As the resilient cellular material of the anchor 20fis compressed, the passage 30fwhich extends through the anchor 20fwhen the anchor is in its unrestrained condition, is collapsed tightly inward against the portion 44fof the suture 32f. In addition, as the anchor 20fis resiliently compressed from its unrestrained condition, the cells in the anchor are collapsed. Thus, the anchor 20fis resiliently compressed from an unrestrained condition to the compacted or compressed condition of FIG. 11 in much the same manner as in which a sponge may be compressed.

[0098] The compressed anchor 20f, with the suture 32fextending through the anchor and the inner sleeve 72f, is inserted into the outer sleeve 66f. The inner sleeve 72fthen pushes the compressed anchor axially downward (as viewed in FIG. 11) into the outer sleeve as the telescopic relationship between the inner and outer sleeves is increased.

[0099] When the anchor 20fis in the outer sleeve 66f, the inner side surface 68fof the outer sleeve applies force against the outer side surface 26fof the anchor to hold the anchor in its compressed condition. Upon movement of the anchor 20fout of the outer sleeve 66finto the body tissue 22f, the force holding the anchor 20fin a compressed condition is removed from the outer side surface 26fof the anchor. As this occurs, the natural resilience of the cellular material forming the anchor 20fcauses the anchor to expand.

[0100] As the anchor 20fexpands, the anchor applies force against the soft body tissue 122fand increases the size of the cavity which was originally formed by the outer sleeve 66fof the inserter assembly 60f. As the anchor 20fexpands, it applies force against the soft body tissue 122fand displaces the soft body tissue. Thus, the outer side surface 26fof the anchor 20fis pressed against the soft body tissue 122fand moves the soft body tissue as the anchor expands radially outward.

[0101] As the anchor 20fexpands, the cells in the anchor are expanded from a collapsed condition to an expanded condition. As the size of the cells in the anchor 20fincreases, body liquids are drawn into the cells. Thus, the anchor 20fabsorbs body liquid as it expands.

[0102] The anchor 20fis formed of a resilient polymeric material having an open cell, sponge-like construction. When the anchor 20fis in the compressed condition illustrated in FIG. 11, the cells are collapsed. As the anchor 20fexpands in the body tissue 22f, the cells expand. Since the anchor 20fhas an open cellular construction, body liquid can flow into the cells as the anchor expands.

[0103] Once the anchor 20fhas expanded in the body tissue 22f, the expanded anchor is substantially larger than the opening which was formed in the body tissue by insertion of the outer sleeve 66finto the body tissue. However, it should be understood that due to force applied against the anchor 20fby the body tissue 22f, the anchor may not expand fully back to its unrestrained size. As the outer sleeve 66fis withdrawn from the body tissue, the visco-elastic nature of the body tissue causes the body tissue to come together and close off the passage which was formed by the insertion of the outer sleeve 66finto the body tissue. Thus, the body tissue will move inward and grip the legs or portions 34fand 38fof the suture 32f. The anchor 20fwill fill a cavity formed in the body tissue 22fby expansion of the anchor.

[0104] The expansion of the anchor 20fin the body tissue results in the formation of an interlock between the anchor and the body tissue to prevent the anchor from being pulled out of the body tissue under the influence of tension applied to the suture 32f. The suture 32fmay be used to position a member which is body tissue, in the manner similar to that illustrated in FIGS. 3 and 4, or may be used to position a splint or implant member relative to the body tissue. Since the expanded anchor 20fhas a firm interlock with the body tissue 122f, tension forces transmitted through the suture 32fbetween the anchor 20fand a member held in place by the suture will not pull the anchor 20fout of the body tissue.

[0105] In FIG. 11, the compressed suture anchor 20fis being inserted into a solid mass of soft body tissue 122f. However, it is contemplated that the suture anchor 20fcould be inserted into either a natural or artificial body cavity. If this was done the suture anchor 20fwould expand to at least partially fill the body cavity.

[0106] In the embodiment of the invention illustrated in FIG. 11, the anchor 20fmoves through the open end portion 170 of the outer sleeve 66finto the body tissue 22f. In the embodiment of the invention illustrated in FIG. 12, the outer sleeve has a closed pointed end portion and the anchor is moved from the outer sleeve at a location immediately behind the pointed end portion of the outer sleeve. Since the embodiment of the invention illustrated in FIG. 12 is generally similar to the embodiment of the invention illustrated in FIG. 11, similar numerals will be utilized to designate similar components, the suffix letter “g” being associated with the numerals of FIG. 12 to avoid confusion.

[0107] An anchor 20ghas the same construction and is formed of the same resilient open cell material as the anchor 20fof FIG. 11. A suture 32ghas a leg or portion 34gwhich extends from a flat annular trailing end surface 36gof the cylindrical anchor 20g. A second leg or portion 38gof the suture 32gextends from a flat annular leading end surface 40gof the anchor 20g. A portion 44gof the suture 32gextends through the anchor and interconnects the legs or portions 34gand 38g.

[0108] The two legs or portions 34gand 38gof the suture 32gextend through a cylindrical central passage in an outer sleeve 72gof an inserter assembly 60g. The inner sleeve 72gis disposed in a telescopic relationship with a cylindrical outer sleeve 66gof the inserter assembly 60g. The inner sleeve 72gcooperates with the outer sleeve 66gin the same manner as previously explained in conjunction with the inserter assembly of FIG. 11.

[0109] In accordance with a feature of this embodiment of the invention, the outer sleeve 66ghas a solid pointed end portion 170gwith a generally conical configuration. The pointed end portion 170gis utilized to pierce an imperforate surface of body tissue in much the same manner as in which the end portion 170 of the outer sleeve 66fof the inserter assembly 60f(FIG. 11) is used to pierce an imperforate surface 114fof the body tissue 22f.

[0110] In accordance with one of the features of the present invention, the outer sleeve 66ghas a generally oval opening 180 in a cylindrical outer side surface 182 of the outer sleeve 66g. The opening 180 is connected with a central passage 68g. The passage 68gextends from an open upper (as viewed in FIG. 12) end portion of the outer sleeve 66gto the solid pointed leading end portion 170g.

[0111] When the outer sleeve 66ghas been inserted to the desired depth in body tissue, the inner sleeve 72gis moved axially downward (as viewed in FIG. 12) and the anchor 20gis forced along an arcuate cam surface 184 leading to the opening 180. This results in the anchor 20gbeing forced from the passage 68gin the outer sleeve 66ginto the soft body tissue. As this occurs, the leading end 40gof the anchor 20gapplies force against the body tissue to displace the body tissue and provide space for the anchor.

[0112] As the anchor 20gmoves along the passage 68gand through the opening 180, the orientation of the anchor relative to the body tissue changes. Thus, the orientation of the anchor 20gchanges from the orientation shown in FIG. 12 to an orientation similar to the orientation of the anchor 20 in FIG. 3. This pivotal movement of the anchor 20gresults in the anchor moving from an initial orientation in which a central axis of the anchor extends parallel to and is coincident with a central axis of the outer sleeve 66gto an orientation in which the central axis of the anchor 20gextends perpendicular to the central axis of the outer sleeve 66g.

[0113] As the anchor 20gexits from the passage 68gin the outer sleeve 66g, the anchor 20gexpands under the influence of its own natural resilience and further displaces body tissue. Once the inner sleeve 72ghas been moved downward to the maximum extent possible, that is, to a position in which the leading end of the inner sleeve 72gengages the cam surface 184, the inner and outer sleeves are withdrawn together from the body tissue. As this occurs, engagement of the anchor 20gwith the body tissue causes the trailing end portion of the anchor to move out of the passage 68gin the outer sleeve 66g.

[0114] As the outer sleeve 66gcontinues to be withdrawn, the pointed leading portion 170 of the outer sleeve moves upward (as viewed in FIG. 12), past the anchor 20g. As this occurs, the anchor 20gexpands into the space previously occupied by the leading end portion 170gof the outer sleeve 66g. As the outer sleeve 66gand inner sleeve 72gare withdrawn from the body tissue, the visco-elastic body tissue closes around the anchor 20gand the legs 34gand 38gof the suture 32g.

[0115] As the anchor 20gis forced from the outer sleeve 66ginto the body tissue and expands, cells in the anchor 20galso expand. As the cells in the anchor 20gexpand, body liquid is drawn into and at least partially fills the cells in the anchor. The anchor 20ghas an open cellular construction, similar to the construction of a sponge. The anchor 20gis resiliently compressed prior to insertion into the outer sleeve 66gso that the cells in the anchor 20gare resiliently collapsed until the anchor is allowed to expand as it is forced out of the side opening 180 in the outer sleeve 66g.

[0116] In the embodiment of the invention illustrated in FIGS. 1-3, the general configuration of the anchor 20 is illustrated as being maintained constant. Thus, the anchor 20 has a cylindrical tubular configuration with a linear central axis. In the embodiment of the invention illustrated in FIG. 13, the configuration of the anchor is changed while the anchor is in a patient's body tissue. Since the embodiment of the invention illustrated in FIG. 13 is generally similar to the embodiment of the invention illustrated in FIGS. 1-4, similar numerals will be utilized to designate similar components, the suffix letter “h” being associated with the numerals of FIG. 13 to avoid confusion.

[0117] A suture anchor 20hhas the same construction and is formed of the same hydrophilic polymeric material as the suture anchor 20 of FIGS. 1-3. The suture anchor 20h(FIG. 13) has a cylindrical tubular configuration. The suture anchor 20hhas a cylindrical outer side surface 26h. A cylindrical central passage (not shown) extends through the suture anchor 20hbetween opposite annular end surfaces 36hand 40hof the suture anchor 20h.

[0118] A suture 32hhas a leg 34hwhich extends frog an annular end surface 36hof the anchor 20h. A second leg 38hof the suture 32hextends from the opposite end surface 40hof the anchor 20h. The anchor 20his inserted into body tissue 20hin the same manner as in which the anchor 20fof FIG. 11 is inserted into the body tissue 22f. Thus, an inserter assembly, similar to the inserter assembly 60fof FIG. 11, is used to position the anchor 20hin the body tissue 22h. The inserter assembly may include a tubular outer sleeve, corresponding to the sleeve 66fof FIG. 11 and a tubular inner sleeve, corresponding to the inner sleeve 72fof FIG. 11. However, the inner sleeve 72fis provided with a conical leading end portion having a configuration corresponding to the configuration of the leading end portion 74 (FIG. 1) of the inner sleeve 72. This enables the inserter assembly to pivot the suture anchor 20hto the position shown in FIG. 13.

[0119] The outer sleeve of the inserter assembly which is used to position the anchor 20hin the body tissue 22hhas a pointed leading end portion, corresponding to the pointed leading end 170 of the outer sleeve 66fof the inserter assembly 60fof FIG. 11. The pointed leading end of the outer sleeve of the inserter assembly was used to pierce the imperforate outer side surface 114hof skin 120hand to enter soft body tissue 122h.

[0120] As the anchor 20hwas positioned in the soft body tissue 122h, the opposite legs 34hand 38hof the suture 32hwere tensioned. This resulted in the suture 32happlying force against the opposite flat annular end surfaces 36hand 40hof the anchor 20h. The force applied to opposite ends of the anchor 20hby the suture 32hpulled the outer side surface 26hof the anchor against the body tissue 122h. In addition, the force applied against opposite ends of the anchor 20hby the suture 32hcaused the suture to bend from an initial configuration to the deflected configuration shown in FIG. 13.

[0121] When the anchor 20hwas in the initial configuration, the anchor 20hhad a straight longitudinal central axis, the same as the anchor 20 of FIGS. 1-3. However, tensioning the suture 32hcaused the legs 34hand 38hof the suture to apply force against opposite ends of the anchor 20hand pull the anchor against the body tissue 122h. As this occurred, the anchor was deflected to the arcuate configuration illustrated in FIG. 13. Since the anchor 20his formed of the same hydrophilic polymeric material as the anchor 20 of FIGS. 1-3, the anchor 20habsorbs body fluid and expands in the body tissue 122hwhile the anchor has the deflected configuration illustrated in FIG. 13.

[0122] In the embodiment of the invention illustrated in FIG. 13, the configuration of the anchor 20his changed from an initial configuration in which the anchor has a straight longitudinal central axis to a configuration in which the anchor has an arcuate longitudinal central axis by tensioning the suture 32hto apply force against opposite ends of the anchor. In the embodiment of the invention illustrated in FIG. 14, the configuration of the anchor is changed from an initial configuration to a deflected configuration by tensioning a suture which is connected with a central portion of the anchor. Since the embodiment of the invention illustrated in FIG. 14 is generally similar to the embodiment of the invention illustrated in FIG. 13, similar numerals will be utilized to designate similar components, the suffix letter “j” being associated with the numerals of FIG. 14 to avoid confusion.

[0123] An anchor 20jhas an outer side surface 26j. The outer side surface 26jextends between opposite end surfaces 36jand 40jof the anchor.

[0124] A suture 32jis connected with a central portion of the anchor 20jdisposed between the opposite end surfaces 36jand 40j. The anchor 20jis formed of the same hydrophilic polymeric material as the anchor 20 of FIGS. 1-3. The anchor 20jis inserted into body tissue 22jin the same manner as described in connection with the embodiment of the invention illustrated FIG. 13.

[0125] Prior to insertion of the anchor 20jinto the body tissue 22j, the anchor 20jhas a solid cylindrical configuration with a straight longitudinal central axis. As the anchor 20jis inserted into the body tissue 22jand moved to the orientation shown in FIG. 14, the suture 32jis tensioned. Tensioning of the suture 32jpresses the outer side surface 26jof the anchor 20jagainst the body tissue 22j. As this occurs, the anchor 20jis deflected from its initial configuration to the deflected configuration illustrated in FIG. 14. When the anchor 20jis in the deflected orientation, the longitudinal central axis of the anchor has an arcuate configuration.