Tissue engagement devices and methods

Abstract

The present invention provides a device that prevents damage to local tissue and the loss of the original fixation position established by repair. [Solution] A soft tissue engagement device (100) is disclosed. The soft tissue engagement device (100) comprises a substantially rigid elongated body extending from a first end to a second end. The elongated body is configured to be inserted at least partially into the soft tissue (10) across the load-bearing direction of the tissue. The elongated body is further configured to engage with sutures (202) attached to base suture anchors (412a, 412b) fixed to the bone (20), thereby pulling the soft tissue (10) onto the bone (20). A method for attaching soft tissue to bone is also disclosed.

Description

Technical Field

[0001] The present disclosure relates to devices and methods for engaging biological tissue.

Background Art

[0002] Injury can result in the complete or partial detachment of soft tissue, such as a ligament or tendon, from bone, or the complete or partial cutting of soft tissue.

[0003] The current standard of care for repairing such injuries is to reattach the detached end of the tissue to the bone or to reattach the cut end of the tissue. This is typically accomplished using sutures that are passed through the soft tissue. In the case of reattachment to bone, the sutures can be secured to an anchor inserted into the bone where the tissue is approximated. The repair needs to have sufficient strength to prevent the tissue from deviating and separating from the intended attachment site while the tissue is under load. Thus, many different suture techniques and patterns have been developed for the purpose of providing an appropriate tensile strength at the repair site.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the repair is placed under load, the forces are concentrated over the relatively small surface area provided by the sutures. As a result, the sutures can cut longitudinally through the tissue before the ultimate failure of the repair. This phenomenon is sometimes referred to as "cheese wiring" because it is similar to the mechanism of a wire cheese cutter slicing through a block of cheese. This can lead to local tissue damage and loss of the original fixation site established by the repair.

[0005] Any discussion of the documents, acts, materials, devices, or articles contained herein shall not be construed as acknowledging that any or all of these matters constitute part of the prior art or were common knowledge in the art relevant to this disclosure because they existed prior to the priority date of each of the appended claims. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a soft tissue engagement device is provided, comprising a substantially rigid elongated body extending from a first end to a second end, wherein the elongated body is configured to be inserted at least partially into soft tissue across the load-bearing direction of the tissue, and to engage with a suture attached to a base suture anchor fixed to bone, thereby pulling the soft tissue onto the bone.

[0007] Another aspect of the present disclosure provides a soft tissue engagement device comprising a substantially rigid elongated body extending from a first end to a second end, wherein the elongated body is configured to be inserted at least partially into soft tissue across the load-bearing direction of the tissue, and to engage with a base anchor fixed to bone, thereby pulling the soft tissue onto the bone.

[0008] The device typically sits oriented across the load-bearing direction of the tissue in its final position. However, it may be inserted at various angles before being moved to its final position. For example, the device may initially be inserted parallel, perpendicular, or oblique to the load-bearing direction.

[0009] Furthermore, in its final position, the device typically sits parallel to the maximum width of the tissue. That is, in a tendon, the device is typically implanted parallel to the width of the tendon, not parallel to the thickness of the tendon. For example, when used for Achilles tendon repair, the device typically extends in the lateral-medial direction rather than the anterior-posterior direction.

[0010] Soft tissue can be any soft tissue requiring repair, including but not limited to tendons, ligaments, muscles, and cartilage, or in some embodiments, the device may be used in conjunction with tissue such as bone. The device can be used to repair tears, separations, or other damage to soft tissue. In one embodiment, the soft tissue is a tendon, and the damage to be repaired is a tear or complete rupture of the tendon, or separation of the tendon from the bone. In other embodiments, soft tissue includes, but is not limited to, connective tissue such as skin, vascular tissue, and nerve tissue.

[0011] The elongated body of the soft tissue engagement device may be elastically flexible to provide sufficient structural rigidity as well as some degree of flexibility to assist in insertion and positioning within the soft tissue as needed. The device may also promote healing by providing dynamic loading to the soft tissue, for example, by recovering any elastic deformation applied as a result of loading, or by changing the direction of loading due to its position within the tissue.

[0012] The elongated body may be configured to be deformable when implanted so as to substantially conform to the underlying bone. By conforming to the underlying bone, the footprint area and the distribution of load on the bone may be improved, and the elongated body may be configured to be permanently deformable. For example, the elongated body may have a relatively high modulus of elasticity so as to maintain its shape under load, but may be permanently deformable (or pre-formed) to contour the underlying bone. In other embodiments, the elongated body may have a relatively low modulus of elasticity so as to deform under load. In such embodiments, the elongated body may be elastically deformable so as to return to its original shape when the load is removed.

[0013] In some embodiments, the elongated body may be substantially straight. A straight elongated body may be configured to conform substantially to the surface of the underlying bone as described above. In other embodiments, the elongated body may be curved. For example, the elongated member may be contoured to conform substantially to the surface of the underlying bone without deformation or with minimal deformation when implanted. In other embodiments, the curvature of the elongated member may be less than the curvature of the bone, and as a result, deformation of the elongated body is required to increase its curvature to conform to the bone surface. In even further embodiments, the elongated body may be excessively contoured. That is, the elongated body may have a curvature greater than the curvature of the bone, and as a result, deformation of the elongated body is required to decrease its curvature to conform to the bone surface. Such embodiments may provide increased force between the elongated body and the bone at or near the end of the elongated body.

[0014] The elongated body may have a substantially uniform cross-section along its entire length. In other embodiments, the elongated body may have a portion with a relatively larger cross-sectional area. For example, the elongated body may taper along its length from a first end to a second end (or from a second end to a first end). Alternatively, the elongated body may have an intermediate portion with a relatively larger cross-sectional area, tapering towards both the first and second ends. In other embodiments, the first and second ends may have a relatively larger cross-sectional area. For example, one or both of the first and second ends may have retaining lugs configured to prevent each end of the elongated body from entering soft tissue.

[0015] The elongated body may have a circular cross-section. Alternatively, the elongated body may have a flat plate, oval, square, rectangular, triangular, elliptical, or crescent-shaped cross-section. The cross-section may also include periodic spikes, hooks, or other mechanisms for retaining its position within the soft tissue.

[0016] In some embodiments, the elongated body is configured to engage with sutures adjacent to the first and second ends. The outer surface of the elongated body may be at least partially roughened, etched, porous, or ribbed to grip the sutures. In some embodiments, the elongated body may include grooves, slots, or ridges that define the suture engagement area. The sutures may be connected to the inside or outside surface of the device.

[0017] In other embodiments, the device may engage directly with the anchor, eliminating the need for sutures. The device may comprise one or more anchor engagement portions. For example, an elongated body may include one or more openings, holes, hooks, or other anchor engagement elements.

[0018] The elongated body may be made from metal or a metal alloy, or alternatively, from a polymer material. Examples of suitable materials include stainless steel and its alloys, titanium and its alloys, cobalt-chromium and its alloys, tantalum and its alloys, polyetheretherketone (PEEK), MP35N and its alloys, and graphite / pyrocarbon.

[0019] In some embodiments, the elongated body is at least partially made from a bioabsorbable material. The elongated body may be made from collagen, chitosan, or synthetic polymers including poly(glycolic acid) (PGA), poly(lactic acid) (PLA), and poly(lactic acid-co-glycolide) (PLGA), tricalcium phosphate (TCP), or bioceramic materials including hydroxyapatite (HA). The bioabsorbable material may also contain chemotactic agents or therapeutic substances that promote biological responses such as endovascular growth.

[0020] The elongated body can be made from a radiolucent or radiopaque material.

[0021] Furthermore, a method for attaching soft tissue to bone, the method is The insertion of a soft tissue engagement device into soft tissue, traversing the load-bearing direction of the soft tissue, wherein the soft tissue engagement device comprises a substantially rigid, elongated body extending from a first end to a second end, and the elongated body is configured to engage with a suture attached to one or more suture anchors fixed to bone. The suture is passed from the suture anchor through the soft tissue to the inside of the soft tissue engagement device, Passing the suture over the soft tissue engagement device, Next, a method is disclosed which includes fixing each of the sutures to a suture anchor.

[0022] In this embodiment, the soft tissue can be a tendon. Although an example of a tendon is provided, it should be understood that the method can be equally utilized, for example, to attach another soft tissue such as a ligament to bone.

[0023] The tendon to be repaired can extend from the myotendinous junction, typically to the end fixed to the bone. In some cases, the tendon is damaged and separated from the bone, and the tendon end is not fixed. For such a repair, it is necessary to re-fix the unfixed end to the bone again. As used herein, the term "inner" or "inward" relates to a position towards the junction of the tendon and the muscle, while "outer" or "outward" refers to a position towards or beyond the unfixed end of the damaged tendon. An example of a repair is the repair of the rotator cuff tendon. It should be understood that in repairs other than the rotator cuff, the term "inner" can be replaced by the term "proximal", and the term "outer" can be replaced by the term "distal".

[0024] The soft tissue engagement device can be a tendon engagement device. One or more suture anchors can include two inner anchors positioned within the underlying bone, typically substantially below and aligned with the tendon engagement device. The suture anchor typically comprises one or more sutures attached to the anchor at one end and extending towards the free end.

[0025] When the inner anchor is fixed to the bone, the tendon is manipulated by the surgeon to promote healing by increasing the contact area between the tendon and the bone tissue, and the unfixed end is moved to the correct position above the area of the bone that serves as the tendon's scaffold.

[0026] Once the tendon is correctly positioned, the suture attached to the first inner anchor is passed through the tendon tissue on the inner side of the tendon engagement device, passed over the tendon engagement device, and returned to and fixed to the same inner anchor. The same process can be performed with the second or more inner anchors and associated sutures.

[0027] The above method provides an "inner fixation" of the tendon to the underlying bone. Such inner fixation results in a relatively short suture length, and as a result, when a load is applied to the tendon by muscle contraction, the elongation of the suture is minimized and little relaxation occurs, providing a relatively rigid attachment of the tendon to the bone. However, a surgeon may also desire to fix the tendon to the bone at an outer location.

[0028] The steps outlined below may be added to or may replace the above inner fixation steps. One or more inner anchors may be fixed to the bone so as to line up with and below the tendon engagement device. One or more outer anchors may also be fixed to the bone at a location outside of the desired position of the unfixed end of the tendon. Each anchor may have one or more associated sutures. In this embodiment, the inner anchor has a suture that is fixed to the anchor at a first end and extends towards a free end. When the tendon is correctly positioned, the suture attached to the first inner anchor is passed through the tendon tissue medial to the tissue engagement device, passed over the tendon engagement device, and either crosses the outer surface of the tendon or is alternatively pulled in any outer direction through the tendon tissue before being fixed to the first outer anchor. The suture typically applies a downward force on the tendon, pressing the tendon towards the underlying bone. The same process may be performed with a second or more inner anchors, where the sutures of each inner anchor may be fixed to one or more outer anchors.

[0029] In one embodiment, the method comprises anchoring a first inner anchor to the bone, anchoring a second inner anchor to the bone, spaced apart from the first inner anchor, anchoring a first outer anchor to the bone at a location outside of the first and second inner anchors, anchoring a second outer anchor to the bone, spaced apart from the first outer anchor, To provide a free end to a first suture having a fixed end, wherein the fixed end is fixed to a first internal anchor, and the free end is passed through the internal tendon tissue relative to the tissue engagement device, thereby fixing the free end to a first external anchor. The present invention provides a second suture having a fixed end, wherein the fixed end is fixed to a second internal anchor, and the free end is passed through internal tendon tissue relative to a tissue engagement device, thereby fixing the free end to a second external anchor.

[0030] The method is, To provide a free end to a third suture having a fixed end, wherein the fixed end is fixed to a first internal anchor, and the free end is passed through the internal tendon tissue relative to the tissue engagement device, thereby fixing the free end to a second external anchor. The present invention provides a fourth suture having a fixed end, wherein the fixed end is fixed to a second internal anchor, and the free end is passed through internal tendon tissue relative to a tissue engagement device, thereby fixing the free end to a first external anchor.

[0031] In another embodiment, a method for attaching soft tissue to bone, the method being Inserting a soft tissue engagement device into soft tissue, traversing the load-bearing direction of the soft tissue, wherein the soft tissue engagement device comprises a substantially rigid, elongated body extending from a first end to a second end, and the elongated body is configured to engage with one or more anchors fixed to bone. A method is disclosed that includes attaching one or more anchors to a device.

[0032] In this embodiment, it should be understood that sutures are not required because the soft tissue engagement device is configured to engage directly with the anchor.

[0033] In some embodiments, one or more anchors may be inserted through soft tissue and then fixed to bone following the insertion of a soft tissue engagement device. One or more anchors may be inserted through a soft tissue engagement device and then fixed to bone. One or more anchors may be inserted substantially perpendicular to an elongated body. One or more anchors may pass through one or more openings or engagement mechanisms of each of the soft tissue engagement devices. The connection of the anchors to the soft tissue engagement device may be made by rivet or hook fastening. In other embodiments, the connection may be screw-type.

[0034] Soft tissue engagement devices and / or anchors may be inserted using a guide or jig. The guide may assist in the insertion and alignment of the soft tissue engagement devices and / or anchors. For example, the guide may include a sliding arm configured to insert the soft tissue device through the soft tissue, traversing the load-bearing direction of the soft tissue. The guide may further include one or more punching members configured to insert the anchor into the bone through the soft tissue.

[0035] In another embodiment, a method for repairing soft tissue separated into separate parts, wherein the method is Inserting a first soft tissue engagement device into a first portion of soft tissue, traversing the load-bearing direction of the soft tissue, wherein the soft tissue engagement device comprises a substantially rigid, elongated body extending from a first end to a second end, The method involves inserting a second soft tissue engagement device into a second portion of soft tissue, traversing the load-bearing direction of the soft tissue, wherein the soft tissue engagement device comprises a substantially rigid, elongated body extending from a first end to a second end. A method is described that includes fixing two soft tissue engagement devices to each other with one or more sutures.

[0036] The devices of the present disclosure may be used to repair severed or at least partially severed tendons. One example is the repair of the Achilles tendon. In this embodiment, one device of the present disclosure may be inserted into one tendon end, and a second device may be inserted into the other tendon end. A suture may be applied across the gap between the tendon ends and attached to each device, thereby binding the ends of the tendon together. The positioning of the two devices prevents "cheese wiring" of the tendon ends due to loss of suture and repair position.

[0037] Throughout this specification, it will be understood that the words "comprise," or variations such as "comprises" or "comprising," mean the inclusion of a specified element, integer, or step, or a group of elements, integers, or steps, but not the exclusion of any other element, integer, or step, or a group of elements, integers, or steps. [Brief explanation of the drawing]

[0038] Next, an embodiment will be described, merely as an example, with reference to the accompanying drawings.

[0039] [Figure 1A] The images show top views of prior art tendon repair methods in both non-loaded and loaded configurations. [Figure 1B] The images show top views of prior art tendon repair methods in both non-loaded and loaded configurations. [Figure 2A] Figures 1A and 1B show side views of the tendon repair method in both the non-loaded and loaded configurations, respectively. [Figure 2B] Figures 1A and 1B show side views of the tendon repair method in both the non-loaded and loaded configurations, respectively. [Figure 3A] The images show top views of a tendon repair method using a soft tissue engagement device according to embodiments of the present disclosure in both a non-loaded and a loaded configuration. [Figure 3B]The images show top views of a tendon repair method using a soft tissue engagement device according to embodiments of the present disclosure in both a non-loaded and a loaded configuration. [Figure 4A] Figures 3A and 3B show side views of tendon repair in the non-loaded and loaded configurations, respectively. [Figure 4B] Figures 3A and 3B show side views of tendon repair in the non-loaded and loaded configurations, respectively. [Figure 5] This disclosure shows soft tissue engagement devices according to several embodiments. [Figure 6A] This disclosure shows soft tissue engagement devices according to several further embodiments of the present disclosure. [Figure 6B] This disclosure shows soft tissue engagement devices according to several further embodiments of the present disclosure. [Figure 6C] This disclosure shows soft tissue engagement devices according to several further embodiments of the present disclosure. [Figure 6D] This disclosure shows soft tissue engagement devices according to several further embodiments of the present disclosure. [Figure 6E] This disclosure shows soft tissue engagement devices according to several further embodiments of the present disclosure. [Figure 6F] This disclosure shows soft tissue engagement devices according to several further embodiments of the present disclosure. [Figure 7A] Steps in a method for attaching a tendon to a bone according to one embodiment of the present disclosure are shown. [Figure 7B] Steps in a method for attaching a tendon to a bone according to one embodiment of the present disclosure are shown. [Figure 7C] Steps in a method for attaching a tendon to a bone according to one embodiment of the present disclosure are shown. [Figure 7D] Steps in a method for attaching a tendon to a bone according to one embodiment of the present disclosure are shown. [Figure 7E] Steps in a method for attaching a tendon to a bone according to one embodiment of the present disclosure are shown. [Figure 7F] Steps in a method for attaching a tendon to a bone according to one embodiment of the present disclosure are shown. [Figure 8]Figures 7A to 7F show perspective views of completed tendon repairs using the methods described. [Figure 9] Figure 7 shows an enlarged cross-section of the repair. [Figure 10] A top view of a tendon repair according to another embodiment of the present disclosure is shown. [Figure 11] A side view of a tendon repair method according to another embodiment of the present disclosure is shown. [Figure 12] The load-displacement curves obtained during periodic loading tests of tendon connections to bone according to two embodiments of the present disclosure are shown, compared to repairs using sutures alone. [Figure 13A] This shows an embodiment of an elongated body of a soft tissue engagement device that is deformable to substantially conform to the underlying bone when implanted. [Figure 13B] This shows an embodiment of an elongated body of a soft tissue engagement device that is deformable to substantially conform to the underlying bone when implanted. [Figure 14A] Exemplary embodiments of guides that help achieve alignment and proper placement of soft tissue engagement devices with anchors are shown. [Figure 14B] Exemplary embodiments of guides that help achieve alignment and proper placement of soft tissue engagement devices with anchors are shown. [Figure 14C] Exemplary embodiments of guides that help achieve alignment and proper placement of soft tissue engagement devices with anchors are shown. [Modes for carrying out the invention]

[0040] The soft tissue engagement device of this disclosure is generally shown as 100 in the drawings. The device may be used for tissue repair. For example, device 100 may be used for reattaching soft tissue to bone, or for reattaching severed ends of soft tissue to each other.

[0041] The example primarily refers to the repair of rotator cuff tendons, where the tendon is reattached to the bone. However, it should be understood that the device may be applied to the repair of any soft tissue, ligament, or tendon, or to bone-like tissue, particularly non-weight-bearing bone. As a further example, the device may be used for tendon-to-tendon or tendon-to-bone repair of the rotator cuff tendons, Achilles tendon, or patellar tendon. Furthermore, the device may be used in ligament-to-bone or ligament-to-ligament reattachment. For example, the device may be used for the repair of the anterior cruciate ligament or posterior cruciate ligament. The present invention is not limited to these specific applications and may be used in other procedures. The use of the disclosed device and method may improve resistance to suture breakage or "cheese wiring" of sutures through tissue, thereby improving the tensile strength of the repair. Excessive micro-movement at the repair interface increases the challenge for the body to heal, resulting in increased loose connective tissue and scar tissue formation that does not support function. The device increases the rigidity of the repair, reduces micro-movement at the interface, and improves healing and function.

[0042] Figures 1A, 1B, 2A, and 2B illustrate prior art tendon repair methods. Tendon 10 is anchored to bone 20 by sutures 40 connected from an inner row 50 of suture anchors to an outer row 60 of suture anchors in a suture bridge technique. However, when force is applied to tendon 10 by muscle 30, the sutures 40 cut through tendon 10 in a "cheese wiring" manner. The displacement of the sutures through tendon 10 at points 11 and 12 is shown in Figures 1B and 2B. This displacement not only causes further damage to the tendon 10 tissue but also corresponds to the displacement of the lateral end 13 of tendon 10 from its initial placement on bone 20. This displacement of the lateral end 13 of tendon 10 as a result of "cheese wiring" is irreversible and results in a loss of footprint between tendon 10 and bone 20. That is, the displacement results in a reduction of the available contact area between tendon 10 and bone 20 where bone integration is possible, reducing the effectiveness of the repair. This failure damages the tendon, leaving it with little mechanical integrity for salvage surgery. The present invention also enables improved salvage characteristics after the failure of conventional suture bridge repairs.

[0043] Figures 3A, 3B, 4A, and 4B illustrate a similar tendon repair using the tissue engagement device 100 according to this disclosure. The tissue engagement device 100 is inserted at least partially into the tendon 10, traversing the load-bearing direction of the tendon 10. Sutures 201, 202, 203, and 204 are anchored to the bone 20 and passed through the tendon 10 at points 11 and 12 on the inside of the tissue engagement device 100. Thus, the sutures 201, 202, 203, and 204 are anchored to the bone 20. Figure 4A shows the path of suture 202 from the medial anchor 411 to the lateral anchor 421. Figures 3B and 4B show the response of the tendon repair construct under load. Unlike the constructs in Figures 1B and 2B, the forces acting from the muscle 30 on the tendon 10 are not concentrated at points 11 and 12. Rather, the tissue engagement device 100 engages with the sutures at points 11 and 12, distributing the force applied to the tendon 10 tissue by the sutures 201, 202, 203, and 204 over a larger surface area. This force distribution increases the restorative structure's resistance to suture breakage or "cheese wiring." Furthermore, the use of the tissue engagement device according to this disclosure can reduce the time required to perform tissue repair work by reducing the need for complex suture stitching techniques.

[0044] As shown in Figure 4B, the lateral end 13 of the tendon 10 may be displaced somewhat under load from its initial position on the bone. However, in this case, the displacement is not due to tissue damage to the tendon 10 as shown in Figure 2B, but rather to the elastic deformation of the sutures 201, 202, 203, and 204. Therefore, the displacement is recoverable once the load is removed, and the contact footprint between the tendon 10 and the bone 20 is maintained.

[0045] Figure 5 shows tissue engagement devices 100a to h according to several embodiments of the present disclosure. Each of the tissue engagement devices 100a to h is in the form of an elongated body extending from a first end 101 to a second end 102. The elongated body may be substantially linear, as in embodiments 100a to d and 100g, or it may be curved or wavy, as in embodiments 100e, 100f, and 100h.

[0046] In some embodiments, the elongated body has a substantially circular cross-section, as in devices 100a, 100b, 100c, 100d, and 100e. In other embodiments, the elongated body has an elliptical cross-section, as in devices 100f, 100g, and 100h. In other embodiments, other cross-sectional shapes may be used.

[0047] In some embodiments, the elongated body may have a substantially constant cross-section along its length (as in devices 100a, 100d, 100e, 100f, 100g, and 100h). In other embodiments, the elongated body may have a cross-section that varies along its length. One such example is shown in Figure 100b, which includes lugs 110 at each of its first and second ends 101, 102. The lugs may be configured to substantially prevent the ends 101, 102 of device 100b from slipping into the tissue. In contrast, embodiments without such lugs 110 may be configured to be fully implantable in the tissue.

[0048] In some embodiments, such as device 100c, the device may have a side wall 120 defining an inner lumen 125. The lumen may be configured to receive one or more sutures, wires, or delivery devices. Alternatively or additionally, the device may include one or more openings that may extend all or partially through device 100. For example, openings 131, 132 of device 100c extend through the side wall 120 to the lumen 125. The suture may also be integrated with the device or molded within the device so that it is rigidly fixed and prevented from sliding through it.

[0049] Further embodiments of the device are provided in Figures 6A to 6F. In Figure 6A, the device 100i comprises a central shaft 120 extending through a helical member 121 to the center. The end 122a is pointed to assist in insertion through tissue.

[0050] Device 100j includes a helical member 121 that does not include a central shaft 120.

[0051] The device 100k comprises an elongated body 130 having oppositely oriented lugs 131a and 131b. Each lug has openings 132a and 132b that can be used to receive sutures.

[0052] In Figure 6D, device 100l has four spaced-apart lugs 133 that are aligned. In Figure 6E, device 100m has two lugs 134.

[0053] Lugs 134a and 134b of device 100n provide another embodiment. Lug 134a extends on both sides of shaft 136 and has two openings positioned on opposing sides of shaft 136. Lug 134b has an angled shape, with half extending in a plane perpendicular to the other half.

[0054] The elongated body of the soft tissue engagement device may be configured to be deformable to substantially conform to the underlying bone when implanted. Exemplary embodiments of such a device are shown in Figures 13A and 13B.

[0055] The device 100p in Figure 13A has a substantially linear, elongated body. In this embodiment, the elongated body has a relatively high modulus of elasticity and is configured to deform to partially conform to the surface of the underlying bone 20, as shown in the lower part of Figure 13A. This results in a relatively small contact footprint area between the tendon 10 and the bone 20.

[0056] In other embodiments, for example, in devices 100q, 100r, and 100s shown in Figure 13B, the elongated body has a lower modulus of elasticity and is configured to deform under load to conform to the curvature of the underlying bone. The initial configuration of the device is shown at the top of Figure 13B. Each of these devices conforms to the shape of the bone to take on a final implanted configuration as shown at the bottom of Figure 13B.

[0057] Device 100r, like device 100p, is initially linear. However, because device 100r is more flexible than device 100p, the final contact footprint area between the tendon and bone in Figure 13B is larger than in Figure 13A.

[0058] Device 100s is curved to closely match the curvature of the bone, requiring minimal deformation to conform to the shape of the bone. Device 100q has an excessive contour, i.e., a curvature greater than that of the bone, requiring deformation to reduce the curvature of device 100q in order to fit the bone.

[0059] In one example, the tissue engagement device 100 may be used to repair a detached rotator cuff tendon. The repair method may include the steps shown in Figures 7A to 7F. The surgery may be performed arthroscopically.

[0060] Figure 7A shows the bone 20 and tendon 10 before the repair is initiated. In Figure 7B, two medial anchors 411a and 411b are positioned on the larger rough surface of the bone 20. The tendon 10 is positioned on the bone 20 at the desired fixation location, and sutures 201, 202, 203, and 204 are passed through the medial tendon tissue from the medial anchors 411a and 411b to the tissue engagement device 100, as shown in Figure 7C.

[0061] Next, the tissue engagement device 100 is inserted into the tendon lateral to the musculotendinous junction such that the axis of the device 100 is substantially perpendicular to the axis or loading direction of the rotator cuff tendon. In some embodiments, the tissue engagement device 100 may be inserted through a transverse incision of the tendon 10, or in other embodiments, it may be pushed through the tendon tissue without first making an incision. In other embodiments, it is envisioned that the device may be seated above the tendon on the bursal side or below the tendon on the articular side.

[0062] The sutures are then passed over the tissue engagement device 100 and anchored to one or more anchors. Figure 7E shows two lateral anchors 412a, 412b inserted into the bone 20, while Figure 7F shows sutures 201, 202, 203, 204 anchored to the lateral anchors 412a, 412b to form a suture bridge. For illustrative purposes, the tendon 10 is shown partially transparent in Figure 7F to reveal the location of the tissue engagement device 100. However, in this embodiment, the device 100 is positioned entirely within the tendon.

[0063] In other embodiments, the tissue engagement device 100 may be woven through the longitudinal fibers of the tendon 10. In some embodiments, the device 100 may be inserted into the tendon tissue so as to sew in and out of the tendon tissue. Thus, one or more portions of the device 100 may be extratendinous on the bursal side and / or articular side of the tendon 10. In such embodiments, the extratendinous portion of the tissue engagement device 100 on the articular and / or bursal side of the tendon 10 may be used as an attachment point for a suture.

[0064] Figures 8 and 9 show the completed repair by the method of Figures 7A to 7H. Sutures 201, 202, 203, and 204 are passed from medial anchors 411a and 411b through the medial tendon 10 tissue to the tissue engagement device 100 and fixed to the lateral anchors 412a and 412b. Each of the ends of the tissue engagement device 100 engages with the adjacent sutures 201, 202, 203, and 204.

[0065] In other embodiments, sutures 201, 202, 203, and 204 may be fixed to a single outer anchor 415. In other embodiments, three or more outer anchors may be used.

[0066] In some embodiments, the internal anchor may be omitted. For example, as shown in Figure 10, the suture 200 passes from the external anchor 415 around the tissue engagement device 100 and is secured to the external anchor 415 (other embodiments may use two or more anchors). In other embodiments, the suture may pass through the lumen or one or more openings of the device 100 (for example, as shown in device 100c in Figure 5). Omitting one or more anchors may reduce the overall cost of the repair procedure.

[0067] Alternatively, in some embodiments, the outer anchor may be omitted. For example, as shown in Figure 11, the suture 200 is passed from the inner anchor 400 through the tissue of the tendon 10 and then fixed to the inner anchor 400 so that the suture 200 surrounds the tissue engagement device 100. In such embodiments, the length of the suture is significantly shorter compared to embodiments in which the suture is fixed to an outer row of anchors. This minimizes the possibility of movement of the suture from the tendon attachment site due to elastic deformation. In embodiments having one or more tendon-external portions of the tissue engagement device 100, the suture may be looped through the articular-side tendon-external portion of the tendon 10 and fixed to the inner anchor. This reduces the length of the suture and improves the rigidity of the connection between the tendon 10 and the bone 20.

[0068] However, if only the medial row of anchors is used, as shown in Figure 10, the lateral end 13 of the tendon 10 remains free and is not pressed against the bone. This can hinder optimal healing. Therefore, in some embodiments, an optional second set of sutures may pass from the medial anchors, around the tissue engagement device, to the lateral anchors (or row of anchors), thereby pressing the lateral end of the tendon against the bone. The demand for the second set of sutures in this configuration is low because the majority of the load is directed between the tendon, the device, and the medial sutures / anchors.

[0069] In some embodiments, the guide 500 may be used to insert the soft tissue engagement device 100 and / or one or more anchors. Figures 14A–14C show exemplary embodiments of the guide that help achieve alignment and proper placement of the soft tissue engagement device 100t with anchors 413a and 413b. In Figure 14A, the device 100t is inserted through the tendon 10 traversing the load-bearing direction using the arm 510. As shown in Figure 14B, anchor 413a is then positioned within the bone 20 through the tendon 10 and the anchor-receiving opening 135a of the device 100t using the punch 520a. Anchor 413b is similarly positioned using the punch 520b, as shown in Figure 14C. It should be understood that in this embodiment, the need for sutures is eliminated because the device 100t engages directly with anchor 413ab.

[0070] In some embodiments, one or more tissue engagement devices may be used to attach one severed end of a soft tissue structure to another severed end. For example, the devices may be used to reattach the severed end of a tendon or ligament. In such embodiments, a first tissue engagement device may be inserted into the tissue at the first severed end, while a second tissue engagement device may be inserted into the second severed end of the tissue. A suture may then be passed through the tissue, around the tissue engagement devices, and tied to form one or more loops, thereby fixing the severed ends of the tissue together. Similar to connections of soft tissue to bone, tissue engagement devices may improve resistance to suture breakage or "cheese wiring" of the suture passing through the tissue, thereby improving the tensile strength of the repair.

[0071] Figure 12 shows load-displacement curves for three tendon repairs subjected to periodic loads of 5–50 N. Curve 510 corresponds to a control tendon repair constructed using medial and lateral rows of bone anchors connected by suture bridges. Curve 520 corresponds to a tendon repair constructed using the tissue engagement device according to this disclosure in combination with medial and lateral rows of bone anchors connected by suture bridges (e.g., as shown in Figures 8 and 9). Curve 530 corresponds to a tendon repair constructed using the tissue engagement device according to this disclosure in combination with only the medial row of bone anchors (e.g., as shown in Figure 11). Compared to control 510, curves 520 and 530 show that repairs constructed with the tissue engagement device of this disclosure are stiffer and exhibit less creep over repeated cycles than the control. The increased creep in control 510 is due to damage to the tendon as sutures “cheese wires” passing through the tissue. Furthermore, because the length of the sutures was reduced, it was clear that the repair using only the internal anchor (curve 530) was more rigid than the repair using both internal and external anchors.

[0072] Those skilled in the art will understand that numerous variations and / or modifications can be made to the embodiments described above without departing from the broad general scope of this disclosure. Accordingly, these embodiments should be considered in all respects illustrative and not limiting. [Explanation of Symbols]

[0073] 10 Soft tissues 13 Outer edge 20 bones 30 Muscles 40 sutures 50 inner row 60 outer row 100 Soft Tissue Engagement Devices 100a~t Tissue Engagement Device 101 First end 102 Second end 110 lag 120 side wall 121-shaped member 122a End 125 internal lumens 130 Main Unit 131 Opening 131a, 131b lag 132, 132a, 132b opening 133, 134, 134a, 134b lag 135a Anchor receiving opening 136 Shaft 200-204 sutures 400, 411, 411a, 411b Inner anchor 412a, 412b, 415, 421 Outer anchors 413a, 413b anchors 500 Guide

Claims

1. A soft tissue engagement device comprising a substantially rigid, elongated body extending from a first end to a second end, wherein the elongated body is configured to be inserted at least partially into soft tissue, traversing the load-bearing direction of the soft tissue, and to engage with a suture attached to a base suture anchor fixed to bone, thereby pulling the soft tissue onto the bone.

2. The soft tissue engagement device according to claim 1, wherein the elongated body is elastically flexible.

3. The soft tissue engagement device according to claim 1 or 2, wherein the cross-section of the elongated body is substantially uniform along the length of the elongated body.

4. The soft tissue engagement device according to claim 1 or 2, wherein the elongated body comprises an area with a relatively larger cross-sectional diameter.

5. The soft tissue engagement device according to claim 1 or 2, wherein the elongated body tapers along its length from one end to the other, or tapers from a central region toward the first and second ends.

6. The soft tissue engagement device according to any one of claims 1 to 5, wherein the elongated body is provided with retaining lugs at one or both of the first and second ends.

7. The soft tissue engagement device according to any one of claims 1 to 6, wherein the elongated body is substantially solid along the length of the elongated body.

8. The soft tissue engagement device according to any one of claims 1 to 6, wherein at least the length of the elongated body is hollow.

9. The soft tissue engagement device according to any one of claims 1 to 8, wherein the side wall of the elongated body includes one or more openings within the side wall for receiving the suture.

10. The soft tissue engagement device according to any one of claims 1 to 9, wherein the elongated body includes an area of ​​rough surface for providing a grip for the suture.

11. The soft tissue engagement device according to any one of claims 1 to 10, wherein the elongated body includes one or more grooves for receiving sutures.

12. The soft tissue engagement device according to any one of claims 1 to 11, wherein the elongated body includes sutures adjacent to each end of the elongated body.

13. A method for attaching soft tissue to bone, wherein the method is Inserting a soft tissue engagement device into the soft tissue, traversing the load-bearing direction of the soft tissue, wherein the soft tissue engagement device comprises a substantially rigid, elongated body extending from a first end to a second end, and the elongated body is configured to engage with a suture attached to one or more suture anchors fixed to bone. The suture is passed from the suture anchor through the soft tissue to the inside of the soft tissue engagement device, Passing the suture over the soft tissue engagement device, A method comprising the steps of: next, fixing each of the sutures to a suture anchor.

14. The method according to claim 13, wherein the one or more suture anchors are one or more internal anchors positioned below the soft tissue engagement device in the underlying bone.

15. The method according to claim 14, wherein the suture is passed from one or more internal anchors through the soft tissue inside the soft tissue engagement device, over the soft tissue engagement device, and returned to and fixed to the one or more internal anchors.

16. The method according to any one of claims 13 to 15, further comprising fixing one or more external anchors to the bone.

17. The method according to claim 16, wherein the suture is passed from one or more internal anchors through the soft tissue inside the soft tissue engagement device, over the soft tissue engagement device, and through the soft tissue outside the soft tissue engagement device, and is fixed to one or more external anchors.

18. The first internal anchor is to be attached to the bone, The second inner anchor is attached to the bone, spaced apart from the first inner anchor. The first outer anchor is fastened to the bone at a location lateral to the first and second inner anchors, The second outer anchor is attached to the bone, spaced apart from the first outer anchor. To provide a free end to a first suture having a fixed end, wherein the fixed end is fixed to the first inner anchor, the free end is passed through the soft tissue inside the soft tissue engagement device, over the soft tissue engagement device, and through the soft tissue outside the soft tissue engagement device, and the free end is fixed to the first outer anchor. The method according to claim 17, comprising providing a free end to a second suture having a fixed end, wherein the fixed end is fixed to the second inner anchor, and the free end is passed through the soft tissue inside the soft tissue engagement device, over the soft tissue engagement device, and through the soft tissue outside the soft tissue engagement device, thereby fixing the free end to the second outer anchor.

19. To provide a free end to a third suture having a fixed end, wherein the fixed end is fixed to the first inner anchor, the free end is passed through the soft tissue inside the soft tissue engagement device, over the soft tissue engagement device, and through the soft tissue outside the soft tissue engagement device, and the free end is fixed to the second outer anchor. The method according to claim 18, further comprising providing a free end to a fourth suture having a fixed end, wherein the fixed end is fixed to the second inner anchor, and the free end is passed through the soft tissue inside the soft tissue engagement device, over the soft tissue engagement device, and through the soft tissue outside the soft tissue engagement device, thereby fixing the free end to the first outer anchor.

20. The method according to any one of claims 13 to 19, wherein the soft tissue is a tendon.

21. The method according to any one of claims 13 to 19, wherein the soft tissue is a ligament.

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