MENISCAL REPAIR DEVICE HAVING INTEGRAL SPRING MEMBER

Abstract: An H-type fastener for tissue. The fastener has a central spring member. The spring member has a first end and a second end. Tissue anchor members are mounted to each end. When placed in tissue, the spring member provides a compressive spring force upon tissue between the anchor members of the fastener.

Description: MENISCAL REPAIR DEVICE HAVING INTEGRAL SPRING MEMBER This is a Continuation-In-Part application of co- pending, commonly assigned patent application Serial No. 08/766,535 filed on December 11, 1996. Technical Field The field of art to which this invention relates is medical devices for tissue approximation, in particular, medical devices for approximating soft tissue. Background of the Invention Recent advances in minimally invasive surgical techniques, such an endoscopy, laparoscopy and arthroscopy, have made it possible for complex surgical techniques to be performed with minimal disruption and cutting of tissue. These techniques are performed using various types of scopes which allow the surgeon to visualize the operative site. The scopes and instruments are designed to be inserted through trocar cannulas which are positioned about the operative site using trocar knives or obturators. The trocar obturators produce minimal punctures when inserted into a body cavity or joint. The body cavity or joint is typically insufflated or expanded with a biocompatible gas or liquid, such as carbon dioxide or sterile saline solution in order to provide the surgeon with room to conduct the surgical procedure. In most surgical procedures, tissue must be approximated to repair wounds and tears and to close incisions. There are numerous known methods and devices for approximating tissue. The devices include surgical needles, surgical sutures, staples and the like. It is also known to use surgical tacks and other fasteners. One particular type of fastener which is known is an "H- shaped" fastener. H-type fasteners and methods of use are disclosed in U.S. Patents No. 4,006,747 and 4,586,502 which are incorporated by reference. The Iltype fastener typically has a central connecting section having opposed ends with tissue anchor members mounted to each end. H-type fasteners and fastening systems for non-medical use are commonly used to affix labels and tags to clothing. The H-type fasteners may have advantages over conventional fasteners in certain minimally invasive techniques. In particular, it is known to use H-type fasteners in arthroscopic techniques such as meniscal repair as disclosed in U.S. Patent No. 5,320,633. Damage to the meniscus, such as rips or tears, has been found to be repairable if the torn pieces of the meniscus are approximated. At one time, the prevailing practice was such that the torn sections of the meniscus would be surgically removed, eventually resulting in damage to the bones in the joint caused by bone-on-bone contact. Presently, however, it has been found that, in order for the eniscal repair to be effective, the opposing surfaces of the torn or ripped meniscus must be approximated such that the surfaces are maintained in close contact. The H-type fasteners are believed to be effective in meniscal repair since they are relatively easy to insert using a conventional apparatus having a cannulated distal needle wherein the needle has a longitudinal slot. One leg or tissue anchor of the H- type fastener is loaded into the cannulated needle, preferably having a slot. The needle is inserted through both sides of the meniscal tear and one leg or anchor is expelled from the needle on one side of the tear. The needle is then removed from the meniscus and the other opposed leg or anchor remains in place positioned on the opposite side of the tear, thereby approximating the meniscal tear. There are certain disadvantages associated with the use of existing H-type fasteners to approximate a tear in a meniscus. One disadvantage is that the surgeon must precisely measure the meniscus prior to inserting the H-type fastener in order to select the proper size H-type fastener. A precise measurement is necessary because the fastener must be sized to approximate and compress the opposing sides or surfaces of the tear against each other. One skilled in the art will appreciate the difficulties involved in attempting to obtain such measurements during an arthroscopic or minimally invasive procedure in which a scope is used. Even if a precise measurement is possible and an appropriately sized H-type fastener is utilized, proper tissue approximation is difficult to accomplish since it is often impossible to precisely place a needle in a meniscus, in vivo, especially during an arthroscopic procedure. Consequently, the meniscus is often under- approximated with inadequate face-to-face contact, or over-approximated with inadequate face-to-face contact. In addition, there are only a limited number of sizes of H-type fasteners which the surgeon will typically have available during an operative procedure, further complicating the surgical procedure and the obtention of adequate tissue to tissue contact in the repaired meniscus. As alluded to above, the surgeon must precisely choose the size of the H-type fastener. If the H-type fastener selected by the surgeon is too large, there will be no tissue approximation. If the H- type fastener is too small, the tissue may fold and bunch, possibly turning the edges or surfaces of the tear so that they are not in contact with each other, thereby effecting only a partial or inadequate repair. What is needed in this art are improved H-type surgical fasteners for approximating tissue which overcome the disadvantages associated with the H-type fasteners of the prior art. Disclosure of the Invention It is an object of the invention to provide an H- type fastener having a spring member section which, when inserted through two adjacent sections of body tissue, causes the edges or surfaces of the tissue to compress against each other by exerting a force upon the tissue. It is yet another object of the present invention to provide an H-type fastener which eliminates or minimizes the need to make precise in-vivo measurements of tissue prior to insertion, and which provides controlled tensioning of tissue. It is still yet a further object of the present invention to provide a method of surgically approximating tissue using an H-type fastener having an integra spring member section, said spring member section providing a spring force to maintain the edges or surfaces of tissue about a tear approximated. Accordingly, an H-type fastener is disclosed. The H-type fastener has an integral central elongated spring member section having a first end and a second end. Mounted to the first end of the spring member is a first tissue anchor. Mounted to the second end of the spring member is a second tissue anchor. The elongated spring member has a resting position, and may be elastically deformed to an extended position. In the extended position, the spring member exerts a spring force. The spring member may have various resting position configurations including saw tooth waves, sine waves, helixes, arcs, parabolas, combinations of straight and curved sections, and the like. The tissue anchors may similarly have a variety of configurations and may be rod-shaped, disk-shaped, spherical, etc. The H-fasteners provide for the controlled tensioning of tissue. Yet another aspect of the present invention is an H-type fastener. The H-type fastener has an elongated central connecting member having a first end and a second end. Mounted to the first end of the central member is a first spring tissue anchor. Mounted to the second end of the connecting member is a second spring tissue anchor. The spring tissue anchors have a first resting configuration and a second elastically deformed configuration. When elastically deformed, the spring tissue anchors exert a spring force upon tissue. Yet another aspect of the present invention is a method of approximating tissue using the tissue approximating H-fasterer devices of the present invention. The method consists of inserting an H-type fastener of the present device having a central spring section into tissue. Next, one tissue anchor is moved to a first position in or about the tissue, and the second anchor is moved to a second position in or about the tissue such that the spring section is elastically displaced from its resting position to an extended position, thereby causing tissue between the anchors to be approximated and causing a spring force to be exerted upon the tissue. Still yet another aspect of the present invention is a method of approximating tissue using the tissue approximating devices of the present invention. The method consists of inserting an H-type fastener of the present device having spring tissue anchors and a substantially non-extendable central member into tissue. Next, one spring tissue anchor is moved to a first position in or about the tissue, and the spring second anchor is moved to a second position in or about the tissue such that the spring tissue anchors are elastically displaced from their resting positions to extended positions, thereby causing tissue between the anchors to be approximated and causing a spring force to be exerted upon the tissue. The spring anchors may also have a variety of configurations including V-shaped, X- shaped, etc. These and other aspects of the present invention will become more apparent from the following description and accompanying drawings . Brief Description of the Drawings FIG. 1 is a perspective view of an H-type fastener of the present invention having a semicircular spring member section. FIG. 1A is a side view of the H-type fastener of FIG. 1. FIG. 2 is a perspective view of an H-type fastener of the present invention having a helical spring member section. FIG. 2A is a side view of the H-type fastener of FIG. 2. FIG. 3 is a perspective view of an H-type fastener of the present invention having a spring member section with a saw-tooth configuration. FIG. 3A is a side view of the H-type fastener of FIG. 3. FIG. 4 is a perspective view of an H-type fastener of the present invention having a sinusoidal spring member section. FIG. 4A is a side view of the H-type fastener of FIG. 4. FIG. 5 is a perspective view of an H-type fastener of the present invention with a spring member section having a 90° arc-shaped configuration. FIG. 5A is a side view of the H-type fastener of FIG. 5. FIG. 6 is a perspective view of an H-type fastener of the present inventing with a spring member section having a 90° arc configuration, and end anchors which are rotated 90 ° with respect to each other. FIG. 6A is a side view of the H-type fastener of FIG. 6. FIG. 7 is a perspective view of an H-type fastener of the present invention wherein the spring member section has a repeating sine wave configuration and also having the tissue anchors with longitudinal axes which are parallel to each other. FIG. 7A is a side view of the H-type fastener of FIG. 7. FIG. 8 is a perspective view of an H-type fastener of the present invention wherein the spring member section has two parallel sawtooth configurations separated by a central opening. FIG. 8A is a side view of the H-type fastener of FIG. 8. FIG. 9 is a perspective view of an H-type fastener of the present invention wherein the spring member section has a two adjoining loops. FIG. 9A is a side view of the H-type fastener of FIG. 9. FIG. 10 is a perspective view of an alternate embodiment of an H-type fastener of the present inventing having a conventional substantially non- extendable straight central connecting section and V- shaped spring tissue anchors mounted to the ends. FIG. 10A is a side view of the H-type fastener of FIG. 15. FIG. 11 is a perspective view of an H-type fastener of the present invention wherein the central spring member is parabolically shaped. FIG. 11A is a side view of the H-type fastener of FIG. 11. FIG. 12 is a perspective view of an H-type fastener of the present invention wherein one tissue anchor has a disk-like shape and the other anchor has a rod-like shape; the spring member has an arc shaped section and a straight section. FIG. 12A is a side view of the H-type fastener of FIG. 12. FIG. 13 is a cross-section of a spring member section of an H-type fastener of the present invention having a circular configuration. FIG. 14 is a cross-section of a spring member section of an H-type fastener of the present invention having an elliptical configuration. FIG. 15 is a cross-section of a spring member section of an H-type fastener of the present invention having a rectangular configuration. FIG. 16 is a cross-section of a spring member section of an H-type fastener of the present invention having a configuration consisting of two squares, each joined together diagonally at a corner. FIG. 17 is a cross-section of a spring member section of an H-type fastener of the present invention having a configuration having two circles tangentially connected. FIG. 18 is a cross-section of a spring member section of an H-type fastener of the present invention having a configuration consisting of a rod with a circle at each end. FIG. 19 is a cross-section of a spring member section of an H-type fastener of the present invention having a square configuration. FIG. 20 is a cross-section of a spring member section of an H-type fastener of the present invention having a cross configuration. FIG. 21 is a top view of a meniscus having a tear. FIG. 22 is a cross-section of the meniscus of FIG. 21 along view line 22-22. FIG. 23 illustrates an arthroscopic measuring device placed adjacent to the meniscus of FIG. 21. FIG. 24 illustrates a cross-sectional view of the meniscus having emplaced therein an insertion needle with an H-type fastener mounted in the insertion needle. FIG. 25 illustrates the meniscus of FIG. 24 after the H-type fastener has been deployed from the insertion needle with the insertion needle still in place in the meniscus. FIG. 26 illustrates the meniscus of FIG. 25 after removal of the insertion needle with the H-type fastener fully deployed in place about the tear in the meniscus, such that the tissue about the tear in the vicinity of the fastener is approximated by the spring force of the central spring member section of the fastener. FIG. 27 is a top view of the meniscus of FIG. 26 illustrating the fastener deployed through the meniscus about the tear and causing the tear to be partially approximated. FIG. 28 is a top a top view of the meniscus of FIG. 27 after with multiple H-type fasteners have been deployed through the meniscus about the tear, thereby approximating the tissue about the tear. FIG. 29 is a cross-sectional view of the meniscus of FIG. 26 illustrating the deployment of an additional, supplemental H-type fastener placed above the fastener initially inserted to provide additional approximation in three dimensions. FIG. 30 illustrates an H-type fastener of the present invention mounted in an insertion needle. FIG. 31 illustrates a side view of the insertion needle of FIG. 30. FIG. 32 is a graph of spring force versus distance for an H-fastener of the present invention. Description of the Preferred Embodiments The H-type fasteners of the present invention may be made from numerous conventional biocompatible polymers. The biocompatible polymeric materials can be either conventional non-absorbable biocompatible polymeric materials, or conventional absorbable or resorbable biocompatible polymeric materials. Examples of the non-absorbable biocompatible materials which can be used include polypropylene, nylon, polyethylene, polyester polyolefin and the like and equivalents thereof. The conventional absorbable and resorbable biocompatible polymeric materials which can be used to manufacture the H-type fasteners of the present invention include polydioxanone, polygalactic acid, polylactic acid, polycaprolactone, copolymers and blends thereof as well as equivalents thereof. The polymers may be mixed with tissue growth enhancing materials such as calcium hydroxyapatite and the like. Examples of some of the foregoing materials are contained in U.S. Patent No. 4,052,988 and U.S. Patent No. 5,252,701. Although not particularly preferred, those skilled in the art will appreciate that the H-type fasteners of the present invention may be manufactured from other conventional types of biocompatible materials including metals such as stainless steel spring steel and nickel-titanium alloys (e.g., Nitinol) , ceramics, composites, and the like and equivalents thereof. The H-type fasteners of the present invention may be manufactured using conventional manufacturing processes. For example, when manufacturing the fasteners of the present invention the following processes, among others, may be used: injection molding, insert molding, extrusion molding, thermal bonding, solvent bonding, annealing, heat treatment, mechanical deformation, heat fusion, welding, machining, cutting, die stamping and forming, etc. Referring now to FIG. 2, a preferred embodiment of an H-type fastener 10 of the present invention is illustrated. The fastener 10 is seen to have central helically-shaped spring member section 12 having first and second ends 14 and 16. Spring member 12 is also seen to have central longitudinal axis 13. Mounted to the ends 14 and 16 of the spring member 12 are the tissue anchors 20. As seen in FIG. 2, tissue anchors 20 are substantially rod-shaped members having opposed rounded ends 22, although anchors 20 may have other configurations, e.g., spheres, discs, beams, etc. The ends of anchors 20 may also be pointed, flat, conical, pyramidal, etc. The tissue anchors 20 are seen to have longitudinal axes 21. The tissue anchors 20 are mounted to the ends 14 and 16 of the spring member 12 such that the longitudinal axes 21 of the tissue anchors 20 are substantially perpendicular to the longitudinal axis 13 of the spring member 12. The anchors 20 are also seen to be centrally mounted to the ends 14 and 16. The axes 21 may be parallel or may be angulated with respect to each other or rotated with respect to each other. An elongation of spring member 12 from a normal resting position to and extended position will result in a spring force being placed upon tissue by anchor members 20 such that when the device 10 is placed into tissue and the spring member 10 is elongated, the tissue between anchor members 20 will be compressed as a result of the spring force exerted upon anchor members 20 by spring member 12. The spring force is proportional to the degree of elongation or deformation of the integral spring member 12. Another embodiment of an H-type fastener of the present invention is seen in FIGS. 1 and 1A. The H-type fastener 30 illustrated in FIGS. 1 and 1A is seen to have central spring member 32 having longitudinal axis 33. Central spring member 32 is seen to have a semicircular configuration with an approximately 180 degree arc, although arcs of lesser magnitude may be used. The spring member 32 is seen to have longitudinal axis 33 and first end 34 and second end 36. Mounted to the first and second ends 34 and 36 of the spring member 32 are the tissue anchors 40. The tissue anchors 40 are seen to be substantially rod-shaped members having rounded ends 42 and longitudinal axes 43. The rod- shaped anchors 40 are centrally mounted to the ends 34 and 36 such that the longitudinal axes 43 of the anchor members are substantially perpendicular to the longitudinal axis 33 of spring member 32 at the ends 34 and 36. If desired, the rod-shaped tissue anchors 40 may be mounted in such a manner that their longitudinal axes 43 are angulated with respect to each other, for example, at 45°, or are rotated with respect to each other, for example, at 90° so that the axes 43 of tissue anchors 40 are not in the same plane. FIGS. 3 and 3A illustrate yet another embodiment of the H-type fasteners of the present invention. The fastener 50 is seen to have central spring member section 52 having first and second ends 54 and 56 respectively. The spring member 52 is seen to have longitudinal axis 57. Mounted to the first and second ends 54 and 56 of the spring member 52 are the rod- shaped tissue anchors 60. Tissue anchors 60 are rod- shaped members centrally mounted to the ends 54 and 56 respectively such that the longitudinal axes 63 of the anchors 60 are substantially perpendicular to the longitudinal axis 57 of spring member 52. The spring member 52 is seen to have a saw-tooth configuration. Another embodiment of an H-type fastener of the present invention is seen in FIGS. 4 and 4A. As seen in FIG. 4, the H-type fastener 70 is seen to have a central spring member section 72 having a sinusoidal configuration. Central spring member 72 is seen to have first and second ends 74 and 76 respectively, and longitudinal axis 77. Mounted to the ends 74 and 76 of the member 72 are the rod-shaped tissue anchors 80. The rod-shaped tissue anchors 80 are seen to have longitudinal axes 83 and rounded ends 82. The tissue anchors 80 are mounted to the first and second ends 74 and 76 of spring member 72 such that the longitudinal axes 83 of the anchors 80 are substantially perpendicular to the longitudinal axis 77 of the spring member 72. As mentioned previously, the anchors may be mounted in a manner angulated with respect to each other or rotated with respect to each other. Yet another preferred embodiment of the H-type fasteners of the present invention is seen in FIGS. 5, 5A, 6, and 6A. Referring to FIG. 5, an anchor member 90 is seen to have integral central spring member section 92 having first and second ends 94 and 96 respectively. Central spring member 92 is seen to have a curved configuration, e.g., substantially a 90 degree circular arc. As seen in FIG. 5A the tissue anchor members 100 are centrally mounted to the ends 94 and 96 of the spring member 92 such that the longitudinal axes 103 and the longitudinal axis 107 are coplanar, although angulated with respect to each other. A variation of the H-type device 90 is seen in FIGS. 6 and 6A wherein the one tissue anchor member 100 is rotated with respect to the other such that the longitudinal axes 103 of tissue anchors 100 are no longer coplanar. The H-type fastener 90 provides a compressive spring force when implanted in tissue which is proportional to the degree of deformation of spring member 92. It is particularly preferred that the cross-section of the central spring member of the embodiments of FIGS. 5, 5A, 6 and 6A be rectangular. The H-type fastener 90 provides a compressive spring force when implanted in tissue which is proportional to the degree of deformation or elongation of spring member 92. Yet another embodiment of the H-type fastener of the present invention is seen in FIG. 7. The fastener 110 is seen to have spring member section 112 having first end 114 and second end 116. Spring member section 112 has a repeating sinusoidal wave-like configuration. Tissue anchor members 120 are seen to be rod-shaped members having rounded ends 122 with longitudinal axes 123 and are seen to be centrally mounted to the ends 114 and 116 such that the central axes 123 of anchors 120 are substantially perpendicular to the ends 114 and 116. Another embodiment of the H-type fastener of the present invention is seen in FIG. 8. The H-type device 130 is seen to have central spring member 131 having first and second ends 132 and 133 and longitudinal axis 134. The central spring member 131 is seen to have opposed saw-toothed members 135 and central opening 136 separating the saw-toothed members 135. Mounted to the ends 132 and 133 of spring member 131 are the rod-shaped members 137, having longitudinal axes 138 and rounded ends 139. The tissue anchors 137 may be mounted perpendicular to longitudinal axis 134 and may be coplanar or rotated with respect to each other so that they are not coplanar. Anchors 137 may be angulated with respect to each other. Yet another embodiment of the H-type fastener of the present invention is seen in FIGS. 9 and 9A. The fastener 140 is seen to have central spring member section 141 having double loops 145 and 146 and longitudinal axis 148. Spring member 141 is also seen to have ends 142 and 143. Centrally mounted to the ends 142 and 143 are the rod-shaped tissue anchor members 150 having axes 155. The anchor members 150 are substantially perpendicular to the ends 142 and 143 and to longitudinal axis 148, but may be angulated with respect to each other. The tissue anchors 150 may be coplanar or may be rotated about axis 148 so that they are not coplanar Another embodiment of the H-type fastener of the present invention is seen in FIGS. 10 and 10A. The fastener 160 is seen to have central spring member section 161 having ends 162 and 163. The spring member 161 is seen to have straight section 164, intermediate curved section 165, and curved section 166 adjacent to end 163. The tissue anchors that are attached to the ends 162 and 163 are seen to have different shapes. Rod-shaped tissue anchor member 170 is mounted to end 163 while disc-shaped member 175 is centrally mounted to end 162. Still yet another embodiment of the H-type fasteners of the present invention is seen in FIGS. 11 and 11A. Fastener 180 is seen to have a parabolically shaped spring member section 181 having first and second ends 182 and 183 and longitudinal axis 184. Mounted to ends 182 and 183 in a manner as previously mentioned are the rod-shaped tissue anchor members 186 having curved ends 187 and longitudinal axes 188. Another embodiment of the H-type fastener of the present invention is seen in FIGS. 12 and 12A. The fastener 190 is seen to have a central connecting section 190 which is not a spring member in that it is substantially non-elongatable. Connecting section 190 has first and second ends 191 and 192, and longitudinal axis 195. Connecting section 190 preferably has a circular cross-section but may have any cross-section including those illustrated in FIGS 13-20. Mounted to the ends 192 and 193 in a central manner are the spring tissue anchors 200. Anchors 200 have legs 202 and 203 which are angulated with respect to each other and joined at an apex 205 to form a V-shaped structure. Legs 202 and 203 are seen to angulate inward toward member 190, but may be situated to angulate in the opposite direction. Anchors 200 may be rotated about axis 195 to be either coplanar or in different planes. Deflection of legs 202 and 203 outwardly away from member 192 from a first resting position to an extended or elastically deformed position will produce a spring force on tissue retained between the anchors 200. Other shapes include U-shapes, a plurality of outwardly extending legs or appendages, inverted cone shapes, cylindrical shapes, X-shapes and other structural shapes as mentioned above for the no-spring tissue anchors. Those skilled in the art will appreciate that the configuration chosen for the central spring member sections of the H-type fasteners of the present invention will depend upon several factors including, but not limited to, the magnitude of the spring force required, the type of tissue to be approximated, the location within the body of the tissue or organ to be approximated, the size of the tear or incision in the tissue, whether absorbable or non-absorbable material is to be used to manufacture the devices, the material of construction, the type of surgical procedure, the amount of elastic deformation desired, etc. It is within the purview of one skilled in the art to choose a final design after weighing these factors. The central spring members of the H-type fasteners of the present invention can have various cross-sections as seen in FIGS. 13-20. Referring to FIG. 13, a cross- section of a preferred embodiment is seen wherein the cross-section 210 is a substantially circular cross- section. A substantially oval cross-section 215 is illustrated in FIG. 14. Illustrated in FIG. 15 is another preferred embodiment having a substantially rectangular cross-section for a spring member of the H- type fasteners of the present invention. Illustrated in FIG. 16 is a cross-section 220 comprising two square cross-sections 223 and 222 having diagonals 227 and 228 which are connected along the diagonals 227 and 228 at the corners 224 and 225. Illustrated in FIG. 17 is a cross-section consisting of two circles 232 and 233 attached tangentially along their circumferences at point 234. Illustrated in FIG. 18 is a cross-section having central rectangular section 242 having ends 243 and 244 with circular sections 247 and 246 extending from ends 244 and 243. FIG. 19 illustrates a rectangular cross- section while FIG. 20 illustrates a cross-type or X-type cross-section having intersecting legs 265. It will be appreciated by those skilled in the art that equivalent cross-sections for the spring member may be chosen. The central connecting members on the anchors of the present invention having spring anchors such as seen in FIG.12 may have similar cross-sections if desired. The tissue anchor members useful on the H-type fasteners of the present invention can have various configurations including rods, disks, cones, spheres, and the like and equivalents thereof. The tissue anchor members may also be configured like structural members having openings therein such as an X-shaped member or a ring member having spokes, or an I-beam, T- beam, etc., and the like and equivalents thereof. In addition, although it is preferred that the anchor members are fixedly mounted to the spring member or connecting member, the anchors may be rotatably mounted using conventional mounting configurations such as ball and socket joints, rivets, pins, snap rings, shafts, bushings, and the like and equivalents thereof. Those skilled in the art will appreciate that the sizes of the H-fasteners of the present invention will vary in accordance with the application, surgical procedure, materials of construction, etc. The spring members when extended will provide a sufficient spring force to effectively approximate or join tissue. For meniscal repair, for example, the spring force will typically be about 1 pound to about 10 pounds, more typically about 2 pounds to about 5 pounds, and preferably about 2.4 pounds to about 3 pounds . The extension of the spring member for meniscal repair will be sufficient to provide for effective tissue approximation; for example, the amount of extension will typically be about 0.020 inches to about 0.240 inches, preferably about 0.050 inches to about 0.075 inches. For meniscal repair, the total percentage extension or elongation as compared to the total device length should, for example, typically be about 10% to about 150%, preferably 15% to about 35%, and more preferably about 23% to about 32%. The H-type fasteners of the present invention can be utilized in many types of surgical procedures to approximate various types of mammalian tissue. The types of tissues which can be approximated include, but are not limited to, ligaments, cartilage, stomach tissue, intestinal tissue, muscle including skeletal muscle, cardiac muscle and involuntary muscle, bone, skin, nerve tissue, blood vessels and connective tissues. It is particularly preferred to use the H-type devices of the present invention to approximate cartilage. In particular, tears in cartilage such as that contained in the meniscus of the knee. It is preferred to apply the H-fasteners of the present invention utilizing an applicator such as that disclosed in co-pending, commonly assigned patent application Serial No. 08/856,102 filed on May 14, 1997 which is incorporated by reference. The H-type fasteners of the present invention are typically utilized in the following manner. Referring to FIGS. 21-29, a meniscus 300 is seen to have a tear 310. The tear 31 is seen to extend from the top 302 of meniscus 300 to the bottom 303 as seen in FIG. 22. The size of the meniscus 300 may be measured using a conventional arthroscopic meniscal measuring device 320 with gradations 322 as seen in FIG. 23. Once the surgeon has measured the size of the meniscus 300, he is able to select an H-type fastener of the present invention which will properly approximate the tear 310 by exerting a spring force on the tissue on either side of the tear 310. For example, fastener 90 of the present invention as illustrated in FIGS 6 and 6A is loaded into a conventional H-type fastener insertion needle delivery device 400 as illustrated in FIGS. 30 and 31. The device 400 is seen to have distal needle cannula 410 having passageway 415, slot 417 in communication with passageway 415 and distal piercing point 412. Mounted to the proximal end 419 of cannula 410 is optional retainer collar 420. Collar 420 is seen to have slot 422 and hook member 425. Proximal leg locking members 440 are seen extend proximally from distal end 419 and are separated by space 441. Each leg has distal base section 445 forming a living hinge and proximal tab members 446. Device 400 is mounted to insertion cannula 500 by depressing the members 440 inwardly and inserting the proximal tab members into passage 510 and locking the tab members 446 in slots 520 contained in cannula 500. Device may similarly be removed form cannula 500 by depressing locking leg members 440 inwardly and thereby causing tab members 446 to dislodge form slots 520. Push rod 530 is seen to be slidably mounted in the passage 510 of cannula 500. H-type fastener 90 is loaded into device 400 by loading one tissue anchor 100 into cannula passageway 415 and the opposed anchor 100 into hook member 425, with spring member section 92 protruding through slots 417 and 422. Once the device 90 is loaded into the distal cannula 410 of delivery device 400, the surgeon then inserts the piercing point 412 through the meniscus 300 such that the needle cannula 410 travels through the meniscus and through tear 310. The surgeon then actuates the push rod 530 to push the tissue anchor member 100 through cannula 410 such that it is positioned adjacent to the surface 305 of meniscus 300. The surgeon then withdraws the needle cannula 410 thereby causing the other anchor 100 to be stripped from the anchor collar hook 425 and further causing spring member 92 to be displaced from cannula 410 and causing the other anchor 100 to be positioned about the surface 307 of meniscus 300. The extended spring member 92 exerts a compressive spring force upon anchors 100 thereby causing the anchors 100 to move inwardly with respect to each other thereby approximating the issue about tear 310. The spring force exerted by member 92 is proportional to the degree of deformation of the member 92 in the extended position. The procedure is repeated to insert additional H-members 90 until the entire tear 310 is approximated as seen in FIGS 27-29. A similar surgical procedure can be performed in a similar manner utilizing H-type fasteners of the present invention having spring tissue anchors such as the fastener illustrated in FIGS. 12 and 12A. The following examples are illustrative of the principles and practices of the present invention. Example 1 A patient was prepared for surgery and anesthetized using conventional procedures. Trocar cannulas were inserted into the capsule surrounding one of the patient's knees in accordance with standard arthroscopic procedures and a flow of saline was established to insufflate the joint. A conventional arthroscope was inserted into one cannula to visualize a tear in the patient's meniscus. After measuring the meniscus with a conventional meniscal measuring device, an appropriately sized H-type fastener of the present invention as seen in FIGS. 6 and 6A was mounted in a cannulated needle and inserted into a trocar cannula. The H-fastener was made from polydioxanone polymer. The point of the needle was inserted through the meniscus and the needle was withdrawn, thereby placing the fastener in the meniscal tissue surrounding the tear and approximating a section of the tear such that the spring member was elongated and exerted a compressive force upon the tissue. Two more fasteners were placed in the meniscus in the same manner thereby repairing the meniscal tear. The cannulas were then removed from the patient's knee and the trocar puncture wounds were approximated in a conventional manner. Example 2 H-fasteners of the present invention having a configuration and spring section in accordance with FIGS. 6 and 6A were tested to determine the spring force produced upon deformation of the spring section. The spring sections of the fasteners had a rectangular cross-section. The H-fasteners were mounted into a conventional tensile force measuring device manufactured by Inotron. Measurements of the forces required to extend the spring section indicated that the resistance for a particular H- fastener was about 2.6 pounds for an extension of about .13 inches. The forces correspond to the spring force that the fastener would exert upon tissue when inserted and displaced to that distance. A graph of the force versus the distance that the spring section was extended is shown in FIG. 32. The sample of H-fastener was unloaded and the spring section allowed to become completely relaxed and was again extended to .13 inches, a force was again observed to be 2.6 pounds. Repeatedly for several additional repetitions, the sample was allowed to completely relax and was again extended to .13 inches and a force was once again measured at about 2.6 pounds . The H-type fasteners of the present invention have many advantages. The fasteners facilitate tissue approximation in minimally invasive surgical procedures such as arthroscopic, endoscopic and laparoscopic procedures. The fasteners of the present invention having integral spring member sections apply a spring force upon tissue which may facilitate healing. The fasteners are particularly useful in approximating tissue, especially tissue such as meniscal cartilage. The fasteners may have other surgical applications as well. Although this invention has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.

Claims: We Claim: 1. An H-type fastener for surgical tissue, comprising a central spring member, said member having a first end, a second end, and a cross section, said member capable of being elastically deformed form a first relaxed resting position to a second extended position; a first anchoring member mounted to the first end of the spring member; and, a second anchoring member mounted to the second end of the spring member. 2. The fastener of claim 1 wherein the spring member has a saw-tooth configuration. 3. The fastener of Claim 1 wherein the spring member has a semi-circular configuration. 4. The fastener of Claim 1 wherein the spring member has a helical configuration. 5. The fastener of Claim 1 wherein the spring member comprises a sinusoidal wave configuration. 6. The fastener of Claim 1 wherein the spring member comprise a square wave configuration. 7. The fastener of Claim 1 wherein the spring member comprises a circular arc configuration. 8. The fastener of Claim 1 wherein the spring member comprises at least one substantially straight section and at least one substantially curved configuration. 9. The fastener of Claim 1 wherein the spring member comprises a circle. 10. The fastener of Claim 1 wherein the cross-section of the spring member comprises an elliptical configuration. 11. The fastener of Claim 1 wherein the cross-section of the spring member comprises a rectangle. 12. The fastener of Claim 1 wherein the cross-section of the spring member comprises a square. 13. The fastener of Claim 1 wherein the cross-section of the spring member comprises an "X". 14. The fastener of Claim 1 wherein the cross-section of the spring member comprises a "T". 15. The fastener of Claim 1 wherein the cross-section of the spring member comprises an I-beam. 16. The fastener of Claim 1 wherein the cross-section of the spring member comprises a pair of squares, each square having corners and a diagonal, the squares each connected at one corner along the diagonal. 17. The fastener of Claim 1 wherein the cross-section of the spring member comprises a pair of circles having circumferences connected at one point about their circumferences. 18. The fastener of Claim 1 wherein the cross-section of the spring member comprises a rectangle having first and second ends, wherein a circle extends from each end. 19. The fastener of claim 1 wherein the spring member has a longitudinal axis. 20. The fastener of Claim 1 wherein the first and second anchoring members comprise elongated cylindrical members having opposed rounded ends . 21. A method of approximating tissue, said method comprising the steps of a) inserting an H-type fastener into tissue, said tissue having opposed first and second sections, wherein the H-type fastener comprises a central spring member, said member having a first end, a second end, a cross section, a longitudinal axis, and a configuration, said member capable of being elastically deformed from a first relaxed resting position to a second extended position; a first tissue anchor mounted to the first end of the spring member; and, a second tissue anchor mounted to the second end of the spring member; b) locating the first tissue anchor in or about one section of the tissue; c) elastically deforming the central spring member to an extended position; d) locating the second tissue anchor in or about a second section of the tissue, thereby applying a compressive spring force to the tissue located between the first and second tissue anchors. 22. An H-type fastener for surgical tissue, comprising an elongated central connecting member, said member having a first end, a second end, and a cross section; a first anchoring spring member mounted to the first end of the central member, said anchoring member capable of being elastically deformed from a first relaxed resting position to a second extended position; and, a second anchoring spring member mounted to the second end of the central member, said anchoring member capable of being elastically deformed from a first relaxed resting position to a second extended position. 23. The fastener of claim 22 wherein the anchoring spring members have a V-shaped configuration comprising two angulated legs connected at an apex and wherein the apex of each tissue mounted is mounted to an end of the elongated central member. 24. A method of approximating tissue, said method comprising the steps of a) inserting an H-type fastener into tissue, wherein the H-type fastener comprises: an elongated central connecting member, said member having a first end, a second end, and a cross-section, ; a first anchoring spring member mounted to the first end of the central member, said member capable of being elastically deformed from a first relaxed resting position to a second extended position; and, a second anchoring spring member mounted to the second end of the central member, said member capable of being elastically deformed from a first relaxed resting position to a second extended position; b) locating the first anchoring spring member in or about one section of the tissue and deforming the first anchoring member to an extended position; c) locating the second anchoring spring member in or about an opposed section of the tissue, and deforming the second anchoring spring member to an extended position; thereby applying a spring force to the tissue located between the first and second anchoring members.

Inventors: KAMMERER GENE W, NAIK RUPAM, SERITELLA KEITH, TREKA-BENTHIN SUSAN, KAMMERER, GENE, W., NAIK, RUPAM, SERITELLA, KEITH, TREKA-BENTHIN, SUSAN
Applicants: ETHICON INC, ETHICON, INC.
Application year: 1999
Main classification: A61B17
IPC codes: A61B17, A61F2