WO2014055765A1

WO2014055765A1 - System and method for tissue capture & anchoring

Info

Publication number: WO2014055765A1
Application number: PCT/US2013/063275
Authority: WO
Inventors: Malcolm Heaven
Original assignee: Kfx Medical Corporation
Priority date: 2012-10-05
Filing date: 2013-10-03
Publication date: 2014-04-10

Abstract

Methods and devices for securing tissue to a rigid material such as bone are provided. A tissue anchor includes an anchor body having a distal end and a proximal end and defining a lumen, and a tissue grasper configured to slideably fit within the lumen between at least a first axial position and a second axial position. The tissue grasper comprises two arms coupled to a shaft and is configured to capture a tissue between the two arms. The anchor body is configured to engage with bone and to secure the tissue anchor and the tissue within a bone. Also described is an exemplary inserter that can be used to insert the tissue anchor and tissue into bone and to facilitate engagement between the anchor body and the bone. A method of using the tissue anchor is also disclosed.

Description

SYSTEM AND METHOD FOR TISSUE CAPTURE & ANCHORING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 61/710,284, filed October 5, 2012, which is incorporated herein by reference in its entirety.

BACKGROUND

Field of the Invention

[0002] The present disclosure relates to medical devices and procedures. More particularly, the disclosure relates to devices and methods for securing soft tissue to a rigid material such as bone. Systems and methods are disclosed herein for fixing tissue such as tendon or ligament to bone in orthopedic procedures.

Description of the Related Art

[0003] There are several medical procedures in which a surgeon needs to attach soft tissue, for example tendons, to bone. One common example is biceps tenodesis, a surgical procedure usually performed for the treatment of partial or complete tears of the biceps tendon, severe tendonitis of the biceps tendon, or biceps instability caused by a rotator cuff tear. The surgery may be performed as an isolated procedure or as part of a larger shoulder surgery, such as a rotator cuff repair.

[0004] The biceps tendons connect the biceps muscle to the bones of the shoulder and the elbow. Two biceps tendons exist near the shoulder that connect the biceps muscle to the shoulder joint. Biceps tenodesis, in its most commonly performed form, is a procedure that involves cutting the normal attachment of the biceps tendon on the shoulder socket and reattaching the tendon to the humerus bone. By performing a biceps tenodesis, the attachment of the biceps tendon may be moved to a position remote from the shoulder joint. Such a result may be beneficial in order to take the pressure of the biceps attachment off the cartilage rim of the shoulder socket or to reestablish a secure connection between tendon and bone.

[0005] Biceps tenodesis repair typically requires the multiple steps of externalizing the tendon, whip stitching the tendon, threading suture through an anchoring device, drilling a bone hole, and screwing the anchoring device and the captured tendon into the bone hole. A portion of the biceps tendon may be surgically removed during the process. It is a difficult procedure to perform arthroscopically and requires significant surgical skill. Conventionally, tendon reattachment is principally achieved by using anchoring devices known as interference screws, which have several drawbacks. Such drawbacks include a substantial risk of tendon laceration and injury, as well as the need to perform multiple steps with significant additional equipment, which contributes to additional costs and extended procedure time.

SUMMARY

[0006] Disclosed herein are various embodiments of a tissue anchor that may address the aforementioned needs. In one disclosed embodiment, the tissue anchor includes an anchor body having a distal end and a proximal end and defining a lumen, and a tissue grasper configured to slideably fit within the lumen between at least a first axial position and second axial position. The tissue grasper has two arms coupled to a shaft. In the first axial position, the arms of the tissue grasper extend outward relative to the shaft, and when the tissue grasper is in the second axial position, the arms are retracted at least partially within the lumen and bent inward relative to the outward extension of the first axial position. The tissue grasper is configured to position and secure a tissue between the two arms.

[0007] In various embodiments, at least a portion of the anchor body includes a first outwardly expandable portion, and the shaft of the tissue grasper includes a camming surface. As the tissue grasper is transitioned to the second axial position, the camming surface contacts an inner surface of the first outwardly expandable portion and thereby causes the first outwardly expandable portion to expand outward. In one such embodiment, the first outwardly expandable portion of the anchor body includes a plurality of tines configured for displacement between an unexpanded position and an expanded position. The tines of one embodiment are shaped like a wedge wherein the wedge protrudes into the lumen when the tines are in an unexpanded position. Each wedge has a first end and a second end, with the wedge bendably coupled to the anchor body at the first end and protruding maximally into the lumen at the second end. Each tine includes, for example, an edge, point, ridge, or plurality of teeth configured to secure the anchor body within a bone. In one disclosed embodiment, the first outwardly expandable portion includes a proximal portion of the anchor body, and the proximal portion is configured such that outward expansion of the proximal portion is greatest at the proximal end of the anchor body. The tissue anchor of one embodiment additionally includes a second outwardly expandable portion located at a distal portion of the anchor body, with the distal portion configured such that outward expansion of the distal portion is greatest at the distal end.

[0008] In a disclosed embodiment, the tissue grasper is configured to slide within the lumen between at least the first axial position, an intermediate axial position, and the second axial position. In the intermediate axial position, the arms of the tissue grasper are reversibly positioned partially within the lumen. A tissue grasper in the intermediate axial position can be retracted further into the lumen to the second axial position or maneuvered to return to the first axial position.

[0009] In a disclosed embodiment, at least one of the two arms includes at least one tooth positioned on an outer side of the at least one of the two arms, and the anchor body includes at least one opening adapted to engage the at least one tooth when the tissue grasper is in the second axial position in order to inhibit movement of the tissue grasper. In another disclosed embodiment, the two arms, additionally or alternatively, include at least one tooth positioned on an inner perimeter of at least one of the two arms, which is configured to secure the tissue in place. In another disclosed embodiment, the anchor body has a distal end of which at least a portion is concave. The anchor body of one embodiment includes a plurality of teeth positioned on the concave portion and configured to help secure the tissue. The anchor body of another embodiment additionally or alternatively includes at least one tab protruding into the lumen, configured to limit movement of the tissue grasper by engaging with at least one depression on the shaft of the tissue grasper.

[0010] Another embodiment is disclosed in which the anchor body includes two flat, parallel sides joined together by two outwardly rounded sides. In one embodiment, the plurality of tines are positioned on the two outwardly rounded sides.

[0011] An embodiment that includes a tissue anchor made of polyether-ether- ketone (PEEK) is also disclosed. In some embodiments, the anchor body has a maximum width of approximately 7 mm to approximately 9 mm when the tissue grasper is in the first axial position and a maximum width of approximately 9 mm to approximately 11 mm when the tissue grasper is in the second axial position. In such an embodiment, the tissue anchor is configured to fit within a bone hole having a diameter that is larger than the maximum width of the anchor body in the first axial position and smaller than the maximum width of the anchor body in the second axial position. Another disclosed embodiment includes an anchor body having a length of approximately 16 mm to approximately 18 mm.

[0012] In one disclosed embodiment, the shaft of the tissue grasper defines an axial bore extending from an opening at a proximal end of the tissue grasper. The axial bore of the tissue grasper and the lumen of the anchor body are configured to receive an inserter tool from a proximal side of the tissue anchor.

[0013] Another disclosed embodiment is for a method of attaching soft tissue to bone. The method includes contacting the soft tissue with a tissue anchor having an anchor body and two distally extending arms, wherein contacting the soft tissue with the tissue anchor involves positioning the soft tissue between the two arms. The method further includes inserting the soft tissue and tissue anchor into a bone hole, and retracting the arms at least partially into the anchor body. Retracting the arms moves the two arms closer together to capture the soft tissue therebetween. The method may further include releasing the soft tissue by extending the arms at least partially from the anchor body, repositioning the arms relative to the soft tissue, and retracting the arms at least partially into the anchor body to recapture the soft tissue between the arms. Additionally or in the alternative, the method may include retracting the arms further into the anchor body to expand at least a portion of the anchor body and thereby secure the tissue anchor in the bone hole. In one disclosed embodiment, expanding at least a portion of the anchor body involves outwardly bending a plurality of tines on the anchor body. In some embodiments, the method additionally includes inserting the tissue anchor through a cannula into a joint region and/or making a bone hole for the tissue anchor, wherein the bone hole is sized to receive the tissue anchor. Upon insertion of the tissue anchor and soft tissue into the bone hole, the soft tissue may fold around the anchor longitudinally. In one embodiment, the inserted soft tissue rests along one or more flat sides of the anchor body. In various embodiments of the disclosed method, the soft tissue is captured and secured without using, for example, sutures, stitching or knots. The method of some embodiments is conducted arthroscopically.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIGURE 1A depicts a perspective view of one embodiment of a tissue anchor in an unengaged state.

[0015] FIGURE IB depicts a perspective view of the tissue anchor of Figure 1A in a fully engaged state.

[0016] FIGURE 2 A depicts a cross-sectional perspective view of one embodiment of a tissue anchor in an unengaged state.

[0017] FIGURE 2B depicts a cross-sectional perspective view of the tissue anchor of Figure 2A in a fully engaged state. [0018] FIGURE 3 depicts a perspective view of one embodiment of an anchor body in an unengaged state.

[0019] FIGURE 4 depicts a perspective view of one embodiment of a tissue grasper in an unengaged state.

[0020] FIGURE 5 depicts a perspective view of one embodiment of a tissue anchor in an unengaged state.

[0021] FIGURE 6 depicts a side view of another embodiment of a tissue anchor in an unengaged state.

[0022] FIGURE 7A depicts a distal-facing perspective view of one embodiment of an anchor body in an unengaged state.

[0023] FIGURE 7B depicts a proximal-facing perspective view of one embodiment of an anchor body in an unengaged state.

[0024] FIGURE 8 depicts a perspective view of one embodiment of a tissue grasper in an unengaged state.

[0025] FIGURE 9 is a perspective view of one embodiment of a tissue anchor in an unengaged state.

[0026] FIGURE 10 is a perspective view of the anchor body of the tissue anchor of Figure 9.

[0027] FIGURE 11 is a perspective view of the tissue grasper of the tissue anchor of Figure 9.

[0028] FIGURE 12 depicts an exploded perspective view of one embodiment of an inserter tool.

[0029] FIGURE 13 is a perspective view of one embodiment of an inner rod.

[0030] FIGURE 14 is a perspective view of one embodiment of an outer rod.

[0031] FIGURE 15 is a perspective view of one embodiment of a cut away portion of a handle body.

[0032] FIGURE 16 is a perspective view of one embodiment of a threaded actuator shaft.

[0033] FIGURE 17 is a perspective view of one embodiment of a deployment knob.

[0034] FIGURE 18 depicts a side view of one embodiment of an inserter tool coupled to a tissue anchor in an unengaged state.

[0035] FIGURE 19A depicts a biceps tendon and biceps muscle positioned on the humerus bone. [0036] FIGURE 19B depicts a biceps tendon that has been captured by one embodiment of a tissue anchor.

[0037] FIGURE 19C depicts a biceps tendon secured within a bone hole by one embodiment of an engaged tissue anchor.

[0038] FIGURE 20 depicts a side view of one embodiment of an engaged tissue anchor that is securing a tendon in a bone hole.

[0039] FIGURE 21 depicts a side view of another embodiment of an engaged tissue anchor that is securing a tendon in a bone hole.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

[0040] In the following detailed description, reference is made to the accompanying drawings, which form part of the present disclosure. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and as illustrated in the Figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are contemplated and form part of this disclosure.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be understood by those within the art that if a specific number of an element is intended, such intent will be explicitly recited in the claim, and in the absence of such recitation, no such intent is present. For example, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and "including," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. [0042] Some embodiments disclosed herein relate generally to anchors for use in anchoring tissue or objects in a body. More specifically, some embodiments disclosed herein relate generally to tissue anchors for use in anchoring tissue, such as soft tissue, to bone. Some descriptions relate to individual components and subcomponents of the systems described herein, as well as methods of using the same. Some embodiments additionally relate to components used in connection with the tissue anchor. Although the following embodiments refer to the use of an anchor in anchoring tissue, a person of skill in the art will recognize that the anchors described in the following embodiments can be used to anchor any range of items within a body.

[0043] The following non-limiting examples illustrate embodiments of a tissue anchor 100. The disclosed embodiments of the tissue anchor 100 simplify arthroscopic procedures, eliminating the need to suture or whip-stitch target tissue. Figure 1A depicts a perspective view of one embodiment of such a tissue anchor 100. The tissue anchor 100 has, in some embodiments, a proximal end 110 and a distal end 120. As shown in Figure 1A, the tissue anchor 100 comprises an anchor body 200 and a tissue grasper 300. In some embodiments, and as depicted in Figure 1 A, the tissue grasper 300 slideably fits into a lumen 240 defined by the anchor body 200. In some embodiments, the tissue grasper 300 can be configured and include features to capture tissue, and the anchor body 200 can, in some embodiments, be configured and include features to secure the tissue and tissue anchor 100 in place within a bone.

[0044] In some embodiments, and as depicted in Figure 1 A, the tissue grasper 300 can be located in a first axial position within and relative to the lumen 240 of the anchor body 200. In some embodiments, the first axial position of the tissue grasper 300 corresponds to an unengaged configuration of the tissue anchor 100. Figure IB provides another perspective view of one embodiment of the tissue anchor 100. In the embodiment depicted in Figure IB, the tissue grasper 300 is located in a second axial position within and relative to the lumen 240 of the anchor body 200. As shown in Figure IB, in some embodiments, when the tissue grasper 300 is in the second axial position, it is retracted proximally into the lumen 240 relative to the first axial position of Figure 1A. In some embodiments, the second axial position of the tissue grasper 300 corresponds to a fully engaged configuration of the tissue anchor 100 in which the tissue grasper 300 is engaged with tissue and the anchor body 200 is engaged with bone. In various embodiments, the tissue grasper 300 is axially slideable relative to the anchor body 200 from at least the first axial position to the second axial position, allowing the tissue anchor 100 to transition at least from the unengaged state (shown in Figure 1A) to the fully engaged state (shown in Figure IB).

[0045] Figures 2A and 2B provide cross-sectional views of the embodiments shown in Figures 1A and IB, respectively. As shown in the cross-sectional views, in some embodiments, the tissue grasper 300 has two arms 310 at the distal end 120 of the tissue anchor 100, which are open and extend out of the distal end of the anchor body 200 when the tissue anchor 100 is in the unengaged state (shown in Figure 2A). In some embodiments, the two arms 310 are substantially closed and retracted within the lumen 240 when the tissue anchor 100 is in the fully engaged state (shown in Figure 2B). In some embodiments, the tissue grasper 300 can receive tissue between the two arms 310 in the unengaged state of the first axial position and can be configured such that the arms 310 bend inward and substantially surround the received tissue when the tissue grasper 300 is retracted proximally into the lumen 240 of the anchor body 200 to enter the fully engaged state of the second axial position.

[0046] In various embodiments, the tissue grasper 300 is configured to transition through one or more intermediate positions when sliding from the first axial position to the second axial position. A tissue grasper 300 in an intermediate axial position can be retracted further into the lumen 240 to the second axial position, such as, for example, the second axial position depicted in Figure 2B or returned toward the first axial position, such as, for example, the first axial position depicted in Figure 2A. In at least some intermediate positions (not shown), the tissue anchor 100 is in a semi-engaged state in which the tissue grasper 300 is retracted partially into the lumen 240 and the arms 310 are bent inward relative to the first axial position. In such a state, the arms 310 can at least partially engage (e.g., by partially surrounding and/or capturing) a soft tissue. In the semi-engaged state of some embodiments, the anchor body 200 is not yet expanded for engagement with surrounding bone.

[0047] The arms 310 of the tissue grasper 300 can comprise a variety of shapes and sizes. In one embodiment, for example, one arm 310 can be hook-shaped and one arm 310 can be substantially straight. In another embodiment, both arms 310 can be curved. In some embodiments, the arms 310 can be similarly or identically shaped and sized. In some embodiments, the ends of the arms 310 touch when the tissue anchor 100 is in the fully engaged state. In some embodiments, the ends of the arms 310 seat one within the other such that a portion of one arm 310 overlaps a portion of the other arm 310 in the fully engaged state. In other embodiments, such as the embodiment shown in Figure 2B, the arms 310 do not touch when the tissue anchor 100 is in the fully engaged state; however, the arms 310 are positioned closely and are configured so as to limit the likelihood that a tissue will slip through the space between the ends of the arms 310. In some embodiments, this space can be, approximately 0.01 mm, 0.02 mm, 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, or any other desired size.

[0048] In some embodiments, the anchor body 200 can be shaped and include features to assist in securing tissue. In one embodiment, such as, for example, the embodiment of Figure 2B, at least a portion of the distal end of the anchor body 200 is concave. In such a configuration, when a tissue is positioned between the arms 310 of the tissue grasper 300, and the tissue grasper 300 is moved from a first axial position to a second axial position so as to move the tissue anchor 100 into its fully engaged state, the concave portion of the distal end of the anchor body 200 and the two arms 310, together, substantially encircle the tissue. The concave configuration of the distal end of the anchor body 200 can, in some embodiments, help cradle the tissue. In some embodiments, a plurality of teeth or sharp protrusions 330 are positioned on an inner side of the two arms 310. In some embodiments, a plurality of teeth 260 are alternatively or additionally positioned on the distal end of the anchor body 200 (for example, on the concave portion of the distal end). In various embodiments, the teeth 330, 260 are configured to engage and secure tissue when the tissue is encircled by the arms 310 of the tissue grasper 300 and the distal end of the anchor body 200.

[0049] In several tissue anchor embodiments, such as, for example, the embodiment of Figures 2A and 2B, the tissue grasper 300 is configured to transition the tissue anchor 100 from an unengaged state to a fully engaged state upon proximal retraction of the tissue grasper 300 into the lumen 240 of the anchor body 200. In some such embodiments, the arms 310 laterally extend beyond the width of the lumen 240 when the tissue anchor 100 is in its unengaged state. In such a configuration, retracting the tissue grasper 300 proximally into the lumen 240 towards an intermediate or a second axial position creates a force on the outer perimeter of the arms 310 that pushes on the arms 310 and causes them to pivot, bend and/or compress toward each other. The arm-moving mechanism can be any suitable structure that allows the arms 310 to pivot, bend or compress. For example, in some embodiments, the arms 310 are integral with the rest of the tissue grasper 300 and made of a bendable material that allows the arms 310 to compress or bend inwardly. In other embodiments, a hinge structure connects the arms 310 to each other or to the shaft 320 of the tissue grasper 300, enabling the arms 310 to pivot inwardly. In some embodiments, the tissue grasper 300 can be retracted proximally into the lumen 240 with the aid of an inserter tool (such as, for example, the inserter tool 1000 described in detail below). In some embodiments, the tissue grasper 300 has an axial bore 350 configured to receive and couple with an inserter tool.

[0050] The tissue anchor 100 is described heretofore and hereafter as being configured to enter a fully engaged state when the tissue grasper 300 is pulled proximally so as to retract the tissue grasper 300 within the lumen 240 of the anchor body 200. However, it will be appreciated by those of skill in the art that the tissue anchor 100 and accompanying inserter tool may be configured such that the fully engaged state can additionally, or alternatively, be achieved when the anchor body 200 is moved or pushed distally forward relative to the tissue grasper 300. Such movement is herein contemplated for all embodiments and forms part of this disclosure.

[0051] In some embodiments, such as the embodiments of Figures 2A and 2B,at least one of the arms 310 comprises one or more protrusions 340 on an outer side, and the anchor body 200 comprises one or more open slots 230. In some embodiments, the one or more open slots 230 comprise at least one slot for each of the one or more protrusions 340 of the arms 310. In other embodiments, the protrusions 340 on the arms 310 are positioned in one or more discrete rows, and the one or more open slots 230 comprise a slot for each protrusion 340 within a row. The protrusions 340 are adapted to couple with the open slots 230 such that one or more protrusions 340 fit within one or more of the open slots 230 and restrict movement of the tissue grasper 300. In some embodiments, the tissue grasper 300 and anchor body 200 are configured such that the protrusions 340 located on the outer side of the arms 310 are positioned distally beyond the distal end of the anchor body 200 when the tissue anchor 100 is in an unengaged state. When the tissue grasper 300 is retracted to a fully engaged state, the protrusions 340 fit within the open slots 230 of the anchor body 200, locking the tissue grasper 300 into place.

[0052] In some embodiments, the arms 310 have two or more rows of protrusions 340 on the outer side associated with various axial positions of the tissue grasper 300. For example, in some embodiments, all protrusions 340 are positioned distally beyond the distal end of the anchor body 200 when the tissue grasper 300 is in the first axial position, a proximal row of protrusions 340 are engaged with a distal row of open slots 230 when the tissue grasper 300 is in an intermediate axial position; and a more-distal row of protrusions 340 is additionally or alternatively engaged with a row of open slots 230 when the tissue grasper 300 is in the second axial position. In other embodiments, the protrusions 340 located on the outer side of the arms 310 are positioned distally beyond the distal end of the anchor body 200 both when the tissue grasper 300 is in the first axial position and when the tissue grasper 300 is in an intermediate axial position. This arrangement allows for movement of the tissue grasper 300 in the distal direction relative to the anchor body 200— from an intermediate axial position back towards the first axial position— if needed.

[0053] In various embodiments, at least a portion of the anchor body 200 is outwardly expandable. In some such embodiments, such as, for example, the embodiments of Figures 2A and 2B, the outwardly expandable portion of the anchor body 200 comprises a plurality of tines 210 configured for displacement between an unexpanded position and an expanded position. The tines 210 are configured to engage with bone when in their expanded position. These tines 210 are configured to move to the expanded position when the tissue grasper 300 is retracted proximally into the lumen 240 toward a second axial position. In some embodiments, the shaft 320 of the tissue grasper 300 has a camming surface 325 configured to interact with an inner surface 212 of the plurality of tines 210 during retraction of the tissue grasper 300 into the lumen 240. In some embodiments, the tines 210 are configured such that, as the tissue grasper 300 retracts, the camming surface 325 of the shaft 320 makes contact with, and applies a force to, the inner surface 212 of each tine 210 and pushes the tines 210 outward relative to the anchor body 200. In some embodiments, the inner surface 212 of each tine 210 is inclined such that each tine 210 is shaped like a wedge. The wedge-shaped tine 210 is configured to taper into the lumen 240 in its unexpanded position. In such a configuration, the wedge-shaped tine 210 can be moveably connected to the anchor body 200 at a distal end of the tine 210, and the maximum protrusion of the wedge into the lumen 240 can be, for example, at the proximal end of the tine 210. In some embodiments, the tines 210 have a thickness substantially equal to the thickness of an outer wall of the anchor body 200. In some such embodiments, the tines 210 comprise a portion of the outer wall of the anchor body 200 but are disconnected from the outer wall on three sides of each tine 210. Such tines 210 are connected to the outer wall on their distal ends and can have sharp protrusions located on their proximal ends. In some embodiments, the tines 210 are recessed into the lumen 240 when in their unexpanded position, such that the sharp protrusions of the tines are generally flush with, or recessed from, the outer wall of the anchor body 200. In some embodiments, when the retracting tissue grasper shaft 320 comes into contact with the inner surface 212 of the tines 210, the tines 210 move outward, bending or deforming about a connection at the distal end of each tine 210. In alternative embodiments, the tines 210 may be connected to the anchor body 200, and move outward relative to the anchor body 200, via hinge structures.

[0054] In some embodiments in which the tissue grasper 300 is configured to transition through one or more intermediate axial positions, the camming surface 325 does not come into contact with the inner surface 212 of the tines 210 until the tissue grasper 300 is nearing the second axial position. For example, the tissue grasper 300 may be configured to transition between a first axial position, one or more intermediate positions, and a second axial position, with the camming surface 325 of the shaft 320 of the tissue grasper 300 contacting the inner surface of the tines 210 for the first time when the tissue grasper 300 approaches the second axial position.

[0055] In the second axial position of one embodiment, such as the embodiment of Figure 2B, a distal row of outer protrusions 340 on the arms 310 are engaged with a row of slots 230 on the anchor body 200, the arms 310 are positioned to substantially surround and engage a tissue, and the camming surface 325 of the shaft 320 has contacted the inner surface 212 of the tines 210, thereby causing the tines 210 to expand to their expanded position. In various embodiments, each tine 210 has one or more edges, teeth, ridges, and/or protrusions 215 adapted to engage bone. When the tines 210 are in their fully expanded position, the one or more edges, teeth, ridges, and/or protrusions 215 extend beyond the outer wall of the anchor body 200 to engage with the bone, securing placement of the tissue anchor 100 within the bone. In some such embodiments, the tines 210 are configured to engage with subcortical bone when the tines 210 expand within the bone hole.

[0056] In one embodiment, an anchor body 200 with a maximum width of 7.5 mm in an unengaged state, and a maximum width of 10 mm in a fully engaged state, is configured for insertion into a bone hole having a diameter of approximately 7.5 mm. In other embodiments, the anchor body 200 has a maximum width of approximately 7 mm to approximately 9 mm in an unengaged state and a maximum width of approximately 9 mm to approximately 11 mm in a fully engaged state. In various embodiments, the tissue anchor 100 is configured to fit within a bone hole having a diameter that is larger than the maximum width of the anchor body 200 when the tissue anchor 100 is in the unengaged state and smaller than the maximum width of the anchor body 200 when the tissue anchor 100 is in the fully engaged state.

[0057] A variety of anchor body designs can be used to achieve expansion within a bone hole and engagement with the surrounding bone. Figure 3 depicts a perspective view of one such embodiment of an anchor body 200. In some embodiments, the anchor body 200 is cylindrically tubular in shape. In other embodiments, the anchor body 200 comprises a substantially hollow rectangular prism with no proximal or distal faces. As shown in Figure 3, in some embodiments, the anchor body 200 has four outer sides comprising two flat, parallel sides 270 joined by two outwardly rounded sides 280.

[0058] In some embodiments, the anchor body 200 can be shaped such that when the anchor body 200 is inserted into a cylindrical hole, some portions of the anchor body 200 more closely approach the walls of the cylindrical hole than other portions of the anchor body 200. In some embodiments, the anchor body 200 is configured such that when two outwardly rounded sides 280 of the anchor body 200 fit snuggly within a cylindrical bone hole, a gap exists between two flat sides 270 of the anchor body 200 and the perimeter of the cylindrical bone hole. In some such embodiments, the tissue grasper 300 can be positioned and aligned within the lumen 240 so that each arm 310 extends from one of the outwardly rounded sides 280 of the anchor body 200. With such a configuration, when a tissue is inserted into a bone hole using the tissue anchor 100, the tissue can rest longitudinally along the two flat sides 270 between the anchor body 200 and the bone. In some embodiments, this configuration can, for example, reduce strangulation of the tissue and allow healthy tissue to contact, and potentially graft to, the bone on two sides of the bone hole along nearly the entire length of the tissue anchor 100. In some embodiments, the tines 210 are positioned on the two outwardly rounded sides 280; this positioning of the tines 210 may enable the tines 210 to expand into the bone and hold the tissue anchor 100 and tissue in place without lacerating the tissue with the sharp edges or protrusions 215 of the tines 210.

[0059] As seen in Figure 3, in some embodiments, locking tabs 220 are located on, or comprise a portion of, the anchor body 200. In some embodiments, a portion or all of the locking tabs 220 protrude into the lumen 240 at least when the tissue anchor 100 is in an unengaged state. In some embodiments, the locking tabs 220 are configured to engage with the tissue grasper 300 to further secure the tissue grasper 300 in the lumen 240 at least when the tissue anchor 100 is in a fully engaged state.

[0060] The locking tabs 220 can comprise a variety of shapes and sizes and can be located in a variety of positions on the anchor body 200. As depicted in Figure 3, the locking tabs 220 can have an elongate, arrow- like shape. As further depicted in Figure 3, in some embodiments, the locking tabs 220 can be connected with the anchor body 200 at one end of the locking tab 220. As specifically depicted in Figure 3, the locking tab 220 is dynamically connected with the anchor body 200 at the distal end of the locking tab 220. Advantageously, the dynamic connection between the locking tab 220 and the anchor body 200 allows angular movement of the locking tab 220 relative to the anchor body 200, which movement can secure, or assist in securing the tissue grasper 300 within the lumen 240 of the anchor body 200.

[0061] Figure 4 provides one embodiment of a tissue grasper 300 for use with the anchor body 200 of Figure 3. The tissue grasper 300 of Figure 4 comprises two distally- located arms 310 coupled to a shaft 320. In some embodiments, the arms 310 contain teeth 340 on an outer side configured to engage with open slots 230 (shown in Figure 3) of the anchor body 200. Additionally or alternatively, the arms 310 include teeth 330 on an inner side configured to engage with tissue. In some embodiments, an axial bore 350 extends through all or a portion of the center of the shaft 320 and is configured to engage with an inserter tool (described in more detail below). The axial bore 350 is defined by an interior wall of the shaft 320. In some embodiments, such as the embodiment depicted in Figure 4, the tissue grasper 300 also comprises at least one indentation or depression 360 on one or more outer sides of the tissue grasper shaft 320. Such indentations 360 can engage with one or more locking tabs 220 (shown in Figure 3) positioned on an anchor body 200. In some embodiments, the indentations 360 and locking tabs 220 provide a secondary locking function and are configured to further restrict movement of the tissue grasper 300 within the anchor body 200. The shaft 320 of the tissue grasper 300 also comprises a camming surface (for example, the rounded surface 325 of the depicted embodiment) configured to facilitate expansion of an expandable portion of an anchor body 200 when the camming surface 325 makes contact with an inner surface of the expandable portion.

[0062] Figure 5 depicts a perspective view of another embodiment of a tissue anchor 100. In the embodiment of Figure 5, the tissue anchor 100 has a proximal end 110 and a distal end 120. As in previous embodiments, the tissue anchor 100 comprises an anchor body 200 and a tissue grasper 300, and the tissue grasper 300 slideably fits into a lumen 240 defined by the anchor body 200. The tissue grasper 300 of Figure 5 is in a first axial position within and relative to the lumen 240, and is configured to slideably transition from the first axial position to a second axial position and through one or more intermediate positions therebetween. In the depicted embodiment, the anchor body 200 comprises two open slots 230 configured to engage with protrusions 340 positioned on the arms 310 of the tissue grasper 300 at least when the tissue grasper 300 in the second axial position in order to limit movement of the tissue grasper 300. The distal end of the anchor body 200 comprises a concave portion having a plurality of teeth 260, which is configured to cradle and engage tissue captured between the arms 310 of the tissue grasper 300. [0063] In the embodiment of Figure 5, a proximal portion 205 of the anchor body 200 is outwardly expandable. Expansion slots 206 are cut into the anchor body 200 at the proximal end and extend in a distal direction such that the outwardly expandable proximal portion 205 comprises a plurality of expandable segments 207 that are disconnected from each other. Each expandable segment 207 is connected to the remainder of the anchor body 200 (i.e., a non-expanding distal portion of the anchor body 200) at a distal end of each respective expandable segment 207. In the depicted embodiment, the expandable segments 207 are configured to flare radially outward when the tissue grasper 300 is retracted proximally into the lumen 240 to the second axial position.

[0064] A side view of another embodiment of a tissue anchor 100 is provided in Figure 6. As in previous embodiments, the tissue anchor 100 has a proximal end 110 and a distal end 120 and comprises an anchor body 200 and a tissue grasper 300. The tissue grasper 300 is configured to fit at least partially within a lumen 240 defined by the anchor body 200 and slideably transition from the first axial position to a second axial position and through one or more intermediate positions therebetween. As in the above-described embodiment, the anchor body 200 of Figure 6 includes an outwardly expandable proximal portion 205 comprising a plurality of expansion slots 206 cut into the anchor body 200 and a plurality of expandable segments 207 connected to a more distal portion of the anchor body 200.

[0065] In some embodiments, the tissue anchor 100 is configured such that, when the tissue anchor 100 is placed in a properly-sized bone hole, the outwardly expandable proximal portion 205 is positioned within the cortical layer of bone. In such embodiments, the expandable segments 207 may be tailored to expand into the cortical layer and provide for cortical fixation. In other embodiments, the expandable segments 207 may be configured for cortical and subcortical engagement. In various embodiments, each expandable segment 207 has a sharp edge, one or more ridges, teeth, or other protrusions 208, which facilitate engagement of the expandable segment 207 with surrounding bone.

[0066] Figures 7A-7B and 8 provide perspective views of the anchor body 200 and the tissue grasper 300, respectively, of Figure 6. Accordingly, Figures 7A, 7B, and 8 will be relied upon to illustrate more details of the tissue anchor 100 of Figure 6. In the illustrated embodiment, the anchor body 200 has four first expandable segments 207 and four first expansion slots 206. In other embodiments, an anchor body 200 can include any desired number of first expandable segments 207 and first expansion slots 206, including ten or less, five or less, four or less, or two first expandable segments 207 and first expansion slots 206. The first expandable segments 207 and first expansion slots 206 can be positioned at any desired radial position around the anchor body 200. In some embodiments, the first expandable segments 207 and first expansion slots 206 are positioned at regular intervals around the anchor body 200. In some embodiments, the first expandable segments 207 and first expansion slots 206 are irregularly positioned around the anchor body 200. Figures 7 A and 7B depict an embodiment of an anchor body 200 in which the first expandable segments 207 and first expansion slots 206 are equiangularly positioned around the anchor body 200. The lengths of first expandable segments 207 and first expansion slots 206 can differ between various embodiments of an anchor body 200. In some embodiments, the first expandable segments 207 and first expansion slots 206 of an anchor body 200 can have equal lengths. In some embodiments, the first expandable segments 207 and first expansion slots 206 may have different lengths such that some of the first expansion slots 206 may extend further toward the distal end of the anchor body 200 than other first expansion slots 206. In some embodiments, the proximal end of one or more of the first expandable segments 207 may not extend as far, proximally, as one or more other first expandable segments 207. Figures 7 A and 7B depict an embodiment of an anchor body 200 in which all first expandable segments 207 and first expansion slots 206 have equal lengths.

[0067] In some embodiments, the anchor body 200, additionally or alternatively, has a plurality of second expandable segments (not shown) extending from a position proximal to the distal end of the anchor body 200 to the distal end of the anchor body 200. Each of the second expandable segments defines a lumen 240 or portion thereof, and is separated from the other second expandable segments by a plurality of second expansion slots. An anchor body 200 can include any desired number of second expandable segments and second expansion slots.

[0068] The second expandable segments and second expansion slots can be positioned at any desired radial position around the anchor body 200. In some embodiments, the second expandable segments and second expansion slots are positioned at regular intervals around the anchor body 200. In some embodiments, the second expandable segments and second expansion slots are irregularly positioned around the anchor body 200. Embodiments of an anchor body 200 can additionally include second expandable segments and second expansion slots of different lengths, similar to the first expandable segments 207 and first expansion slots 206 described above.

[0069] Returning to Figures 7A and 7B, the first expandable segments 207 and first expansion slots 206 (and the second expandable segments and second expansion slots, if present) allow the anchor body 200 to expand when the tissue grasper 300 is moved from a first axial position towards a second axial position. Specifically, the axial displacement of the tissue grasper 300 towards the second axial position results, first, in an outward displacement of the second expandable segments and expansion of the second expansion slots, if present, followed by outward displacement of the first expandable segments 207 and expansion of the first expansion slots 206. In some embodiments, the anchor body 200 can be sized and dimensioned relative to the hole in which the tissue anchor 100 is placed, such that outward expansion of the anchor body causes at least the first expandable segments 207 to engage with surrounding bone. In some embodiments, engagement of the bone by expandable segments can be facilitated by protrusions (e.g., teeth, ridges, sharp edges, etc.) located on some or all of the expandable segments. For example, in Figures 7 A and 7B, the protrusions 208 located on the first expandable segments 207 are configured to facilitate engagement between the expandable segments 207 and bone.

[0070] In some embodiments, the protrusions 208 are designed to prevent the tissue anchor 100 from displacing out of the bone. In some embodiments, the protrusions 208 are designed to stabilize the tissue anchor 100 in the bone. In some embodiments, the protrusions 208 are designed to perform a combination of these and other functions. The protrusions 208 of various embodiments may penetrate the bone; the protrusions 208 may partially penetrate the bone; the protrusions 208 may form depressions in the bone; and/or the protrusions 208 may deform to fit to the bone. In some embodiments, all of the protrusions 208 on the anchor body 200 are similarly sized and dimensioned. In other embodiments, an anchor body 200 may have two or more types, sizes, and/or configurations of protrusions 208.

[0071] In some embodiments, the lumen 240 of the anchor body 200 is completely tubular in shape, being defined by one or more walls that are parallel to the longitudinal/central axis of the anchor body 200. In other embodiments, at least one portion of a wall defining the lumen 240 is perpendicular to, or otherwise angled, relative to the longitudinal/central axis of the anchor body 200. For example, in some embodiments, such as depicted in Figures 7A and 7B, an inner wall 201 of the anchor body 200, surrounding and defining the lumen 240, comprises a first wall portion 202 located proximate to the distal end of the anchor body 200. In some embodiments, the first wall portion 202 is parallel to the longitudinal/central axis of the anchor body 200. In other embodiments, the first wall portion 202 is sloped to provide a guiding surface that facilitates movement of the tissue grasper 300 into the lumen 240. In some embodiments, the inner wall 201 includes a first stop 203 located proximate to the first wall portion 202. As depicted in Figure 7 A, a first stop 203 is a wall segment that is non-parallel to the first wall portion 202. As depicted in Figure 7 A, the first stop 203 is configured to provide an engageable surface which can interact with at least a portion of the tissue grasper 300 to thereby restrict retraction of the tissue grasper 300. In some embodiments, the first stop 203 is positioned to restrict movement of the tissue grasper 300 at an intermediate position. In an intermediate position, the arms 310 of the tissue grasper 300 may be streamlined into a partially closed configuration and the anchor body 200 may still be in an unexpanded, streamlined configuration. Accordingly, it may be desirable to maintain the tissue grasper 300 in an intermediate position during placement of the tissue anchor 100 into a bone hole. In some embodiments, the tissue grasper 300 must be turned or pulled with greater force to move the tissue grasper 300 past the intermediate position toward the second axial position.

[0072] In some embodiments, the anchor body 200 has one or more expandable segments 207 located proximally to the first stop 203. In such embodiments, at least a portion of each expandable segment 207 extends radially into the lumen 240 further than the remainder of the anchor body 200 when an outer wall of each expandable segment 207 is substantially flush with an outer wall of the remainder of anchor body 200. In such embodiments, the expandable segments 207 are configured such that, as the tissue grasper 300 retracts, a camming surface 325 on the tissue grasper 300 (see Figure 8) makes contact with, and applies a force to, the radially-inward extending portion of each expandable segment 207, pushing the expandable segments 207 outward relative to the anchor body 200. In one embodiment, the thickness of each expandable segment 207 increases gradually in a proximal direction such that each expandable segment 207 has an inclined wall 204 having a maximum protrusion into the lumen 240 at a proximal end of the inclined wall 204. In such embodiments, the inner inclined wall 204 is configured to interact with the camming surface 325.

[0073] In some embodiments, upon interaction of the expandable segment 207 with the camming surface 325, the proximal end of the anchor body 200 achieves maximum outward expansion of approximately 4 millimeters, 2 millimeters, 1 millimeter, 0.5 millimeter, or any other desired change in diameter. In some embodiments, such as the embodiment of Figure 7B, one or more of the expandable segments 207 also includes a second stop 209 configured to help secure the tissue grasper 300 against movement once the tissue grasper 300 reaches the second axial position. For example, the second stop 209 may comprise a non-parallel wall, one or more tabs, teeth, ridges, or other protrusions, or one or more slots, grooves, or depressions configured to restrict axial movement of the tissue grasper 300 by engaging with a feature on an exterior wall of the shaft 320.

[0074] Figure 8 provides an illustration of the tissue grasper 300 of Figure 6. In the illustrated embodiment, the tissue grasper 300 has two distally- located arms 310 coupled to a shaft 320. The arms 310 are configured to compress inward toward each other when a force is applied to an outer side of each arm 310, such as, for example, when a force is applied by a distal end of the anchor body 200. In some embodiments, such as the embodiment of Figure 8, at least a portion of each arm 310 is hollow. Such a configuration may provide the arms 310 with greater flexibility and compressibility. In some embodiments, such as the embodiment of Figure 8, an outer side of each arm 310 is smooth. Such a configuration may improve the slideability of the arms 310 into the lumen 240. Additionally or alternatively, the tissue grasper 300 of some embodiments includes one or more protrusions 330 positioned on an inner side of each arm 310. Such a configuration may improve retention of captured tissue within the arms 310 of the tissue grasper 300.

[0075] In the embodiment illustrated in Figure 8, the shaft 320 is substantially cylindrical in shape. Such a tissue grasper 300 may be used with an anchor body 200 having expandable segments 207 arranged radially around an outwardly expandable portion 205 of the anchor body 200 (such as the anchor body 200 of Figure 7). In some embodiments, the cylindrical shape of the shaft 320 may advantageously permit a camming surface 325 on the shaft 320 to apply a uniform force to each expandable segment 207 upon making contact with an inner surface of each expandable segment 207. In some embodiments, such as the embodiment of Figure 8, the shaft 320 also includes an engagement feature to help secure the tissue grasper 300 against movement relative to the anchor body 200 upon reaching the second axial position. For example, either the exterior wall of the shaft 320 or inner wall of the anchor body 200 comprises one or more tabs, teeth, ridges, or other protrusions while the other of said shaft 320 and said inner wall of the anchor body 200 comprises one or more slots, grooves, or depressions configured to receive a protrusion. For example, as shown in Figures 7B and 8, the anchor body 200 includes tabs 209 (also referred to as second stops 209), which are configured to engage with a depression 309 located on the exterior wall of the shaft 320 when the tissue grasper 300 is in the second axial position.

[0076] In some embodiments, such as the tissue grasper embodiment 300 of Figure 8, an axial bore 350 extends through all or a portion of the center of the shaft 320 and is configured to engage with an inserter tool (described in more detail below). In one such embodiment, all or a portion of the interior wall of the shaft 320 and a distal portion of the inserter tool each comprise complementary threading such that the shaft 320 and the inserter tool can be screwed into engagement. In other embodiments, either the interior wall of the shaft 320 or a distal portion of the inserter tool comprises one or more tabs, teeth, ridges, or other protrusions while the other of said interior wall of the shaft 320 and said distal portion of the inserter tool comprises one or more slots, grooves, or depressions, each configured to receive a protrusion. Such a feature may allow the shaft 320 to be snapped or pressed into engagement with an inserter tool. In still other embodiments, the tissue grasper 300 may become engaged to a distal portion of an inserter tool through other securing mechanisms such as adhesives, welding or frictional fit.

[0077] One variation of the embodiments described above with respect to Figures 5-8 is depicted in Figures 9-11. Figure 9 depicts a perspective view of a tissue anchor 100. The tissue anchor 100 has a proximal end 110 and a distal end 120. The tissue anchor 100 comprises an anchor body 200 and a tissue grasper 300, and the tissue grasper 300 slideably fits into a lumen defined by the anchor body 200. The tissue grasper 300 of Figure 9 is in a first axial position within and relative to the anchor body 200, and is configured to slideably transition from the first axial position to a second axial position and through one or more intermediate positions therebetween. The distal end of the anchor body 200 comprises a plurality of teeth 260, which extend around the circumference of the distal end of the anchor body 200. Other teeth configurations, such as described above, are also possible.

[0078] As in the embodiments described above with respect to Figures 5-8, the embodiment of Figure 9 includes a proximal portion 205 of the anchor body 200 that is outwardly expandable. Expansion slots 206 are cut into the anchor body 200 at the proximal end and extend in a distal direction such that the outwardly expandable proximal portion 205 comprises a plurality of expandable segments 207 that are disconnected from each other. Each expandable segment 207 is connected to the remainder of the anchor body 200 (i.e., a non-expanding distal portion of the anchor body 200) at a distal end of each respective expandable segment 207. In the depicted embodiment, the expandable segments 207 are configured to flare radially outward when the tissue grasper 300 is retracted proximally into the lumen to the second axial position.

[0079] In addition, the embodiment of Figure 9 includes a plurality of resilient tabs 290 positioned on the sides of the anchor body 200. These tabs 290 may be formed but cutting portions of the sides of the anchor body 200 to form the tabs 290. Alternatively, the tabs 290 may be added to the sides of the anchor body 200 using any suitable bonding technique. Any number of tabs 290 may be used, including but not limited to 2, 3, 4, 5, and 6 tabs 290. The embodiment depicted in Figure 9 contains 4 tabs 290. In some embodiments, the tabs 290 may be positioned equiangularly around the circumference of the anchor body 200. The tabs 290 may be angled in a proximal direction such that distal insertion of the anchor 100 is facilitated while proximal removal is inhibited. The resilient nature of the tabs 290 may facilitate insertion into a bone hole by allowing the tabs 290 to bend inward as needed to clear the bone hole. Once inserted the tabs 290 may then bias outward to help prevent removal of the anchor 100.

[0080] Figure 10 is a perspective view of the anchor body 200. Figure 11 is a perspective view of the grasper 300. As described above with respect to Figure 8, the tissue grasper 300 of Figure 11 has two distally-located arms 310 coupled to a shaft 320. The arms 310 are configured to compress inward toward each other when a force is applied to an outer side of each arm 310, such as, for example, when a force is applied by a distal end of the anchor body 200. The tissue grasper 300 of Figure 11 includes one or more protrusions 330 positioned on an inner side of each arm 310. Such a configuration may improve retention of captured tissue within the arms 310 of the tissue grasper 300.

[0081] The shaft 320 of Figure 11 is substantially cylindrical in shape. The cylindrical shape of the shaft 320 may advantageously permit a camming surface 325 on the shaft 320 to apply a uniform force to each expandable segment 207 upon making contact with an inner surface of each expandable segment 207. In some embodiments, the shaft 320 also includes a depression 309 configured to receive one or more protrusions in the interior of the anchor body 200, thereby stabilizing the tissue grasper 300 against movement relative to the anchor body 200 upon reaching the second axial position.

[0082] The above described tissue anchor 100 can be made from a variety of materials, including natural or manmade materials. The tissue anchor 100 can be made of metal, plastic, polymer, composite, or other materials. In some embodiments, the tissue anchor 100 is made of a biocompatible polymer, metal, or composite. In one embodiment, the tissue anchor 100 is made entirely of the biocompatible engineering plastic, polyether- ether-ketone (PEEK). In other embodiments, poly-ether-ketone (PEK), polyetherimide (ULTEM), ultrahigh molecular weight polyethylene (UHMPE), polyphenylene, or other biocompatible material(s) known to those of skill in the art may be used. A non-metallic anchor system may provide certain advantages such as, for example, eliminating MRI artifacts.

[0083] As mentioned above, the tissue anchor components can be configured to couple with an inserter tool. In some embodiments, the tissue anchor 100 is configured for coupling with a particular brand or model of inserter tools. The tissue anchor 100 of other embodiments is contemplated for use with many different inserter tool models, designs, and brands. Examples of inserter tools are described here for illustrative purposes only. Figure 12 depicts an exploded perspective view of one embodiment of an exemplary inserter tool 1000. The inserter tool 1000 comprises an inner rod or tube 1100, an outer tube 1200, a handle body 1300, a threaded actuator shaft 1400, and a deployment knob 1500. In some embodiments, the inserter tool 1000 is coupled to the tissue anchor 100 during manufacturing. In another embodiment, the inserter tool 1000 is coupled to the tissue anchor 100 prior to insertion. In some embodiments, the inserter tool 1000 is disposable; in others, the inserter tool 1000 is reusable and made of materials capable of withstanding sterilization procedures. The inserter tool 1000 is designed for insertion and manipulation of tissue anchors, such as the tissue anchors 100 described above.

[0084] In a basic configuration of one embodiment, the inserter tool is assembled as follows: the inserter tool 1000 is configured such that the inner rod 1100 is disposed within the outer tube 1200. The outer tube 1200 is configured to fit against the proximal end of the anchor body 200. The inner rod 1 100 extends through the outer tube 1200 and the lumen 240 in the anchor body 200 and is configured to enter the tissue grasper 300 through the proximal end of the tissue grasper and attach to the tissue grasper 300 within an axial bore 350. The proximal end of the outer tube 1200 is connected to a handle body 1300 and the proximal end of the inner rod 1100 extends through the proximal end of the outer tube 1200 and screws into the threaded actuator shaft 1400. The actuator shaft 1400 extends just past the proximal end of the handle body 1300 where it is configured to secure with a deployment knob 1500. The individual components of one example of an inserter tool 1000 are further described in detail below.

[0085] Figure 13 shows a perspective view of one embodiment of an inner rod 1100. In some embodiments, the inner rod 1100 is a hollow inner tube. In some embodiments, the inner rod comprises a distal end 1110 configured to secure to the tissue grasper 300, and a proximal end 1120, which is configured to interact with the other components of the inserter tool, for instance the actuator shaft 1400. The inner rod 1100 is configured such that the proximal end 1120 extends through the outer tube 1200 and into the handle body 1300 where it is further secured within the actuator shaft 1400 via threading. The distal end 1110 of the inner rod 1100 extends through the lumen 240 defined by the anchor body 200 and couples with the tissue grasper 300 within an axial bore 350. In one embodiment, the inner rod 1100 couples with the tissue grasper 300 through threads 1105 located on the distal end of the inner rod 1100 and threads located within the proximal end of the tissue grasper 300. In other embodiments, the inner rod 1100 may couple to the tissue grasper 300 through other securing mechanisms such as adhesives, welding or frictional fit.

[0086] Figure 14 shows a perspective view of one embodiment of the outer tube 1200. In some embodiments, the outer tube 1200 is attached at its proximal end 1250 to the distal end of the handle body 1300 via threading 1225. The outer tube 1200 is configured such that the inner rod 1100 extends through the outer tube 1200 and out the distal end 1210 of the outer tube 1200 where it is secured to the tissue grasper 300.

[0087] Figure 15 depicts a perspective view of one embodiment of a cut-away view of a handle body 1300. The proximal end of the handle body 1300 is configured to receive the deployment knob 1500 via the ridges 1330 that hold the deployment knob 1500 secure. The actuator shaft 1400 is housed within the handle body 1300. A set of brackets or braces 1312, having a flat surface 1315, secure the actuator shaft 1400 within the handle body 1300. The distal end of the handle body 1300 is configured to receive the outer tube 1200 via a threaded opening 1325. The distal end of the handle body 1300 and the proximal end of the outer tube 1200 are configured to remain fixedly attached to each other via threading while in use.

[0088] Figure 16 depicts the threaded actuator shaft 1400. The actuator shaft 1400 comprises: a distal end 1405 comprising a threaded hole 1410 which is configured to receive and couple with the inner rod 1100, a second threaded portion 1425 on the body of the shaft configured to retract the inner rod 1100, and a proximal end 1420 configured to secure within the deployment knob 1500. The body of the actuator shaft 1400 is configured with threading 1425 to permit the actuator shaft 1400 to retract the inner tube 1100. The body of the actuator shaft 1400 is not perfectly round, but rather comprises flat surfaces 1430 on opposite sides that are configured to fit into the handle body 1300 in such a way that the actuator shaft 1400 cannot itself rotate when the deployment knob 1500 is turned and the shaft 1400 advances via the deployment knob 1500. In one embodiment, the two flat areas 1430 have no threading and fit tightly within the flat brackets 1312 of the handle body 1300 to achieve a configuration where the actuator shaft 1400 does not rotate. The actuator shaft is configured as a coaxial system in which the inner tube 1100 and actuator shaft 1400 are configured to operate as one piece.

[0089] Figure 17 depicts a perspective view of one embodiment of a deployment knob 1500. The deployment knob 1500 comprises: a central hole 1510 which is configured with threading 1505, and a groove 1530 configured to be received by a corresponding ridge 1330 of the handle body 1300. The threading 1505 in the central hole 1510 is configured to receive the actuator shaft 1400. The deployment knob 1500 is configured to retract the inner rod 1100, relative to the deployment knob 1500, via the actuator shaft 1400. The actuator shaft 1400 is joined at its proximal end to the distal end of the deployment knob 1500 via threading 1505 in the central hole 1510. In one embodiment, the deployment knob 1500 is configured to receive the actuator shaft 1400 by way of having the groove 1530 of deployment knob 1500 fit with ridges 1330 of the proximal end of the handle body 1300. The inserter tool 1000 of the illustrated embodiment is configured such that, when the deployment knob 1500 is rotated, the mechanism of the actuator shaft 1400 advances the inner rod 1100 proximally such that the tissue grasper 300 is retracted proximally into the anchor body 200. In some embodiments, rotation of the actuator shaft 1400 and the resultant proximal retraction of the tissue grasper 300 causes the arms 310 of the tissue grasper 300 to close substantially and also causes the outwardly expandable portion of the anchor body 200 to expand. In some embodiments, the deployment knob 1500 can be rotated in either direction, and consequently, the inner rod 1100 can be made to advance or retreat. Thus, in some embodiments, the tissue grasper 300 can be retracted proximally into the anchor body 200 when the deployment knob 1500 is turned in one direction (e.g., clockwise), and the tissue grasper 300 can be returned to a more-distal axial position, at least partially withdrawing it from the anchor body 200, when the deployment knob 1500 is turned in the other direction (e.g., counterclockwise).

[0090] Figure 18 shows one embodiment of a tissue anchor 100 coupled to one embodiment of the inserter tool 1000. The tissue anchor 100 comprises the anchor body 200 and the tissue grasper 300. The inserter tool 1000, as shown, includes the outer tube 1200, the handle body 1300, and the deployment knob 1500. The inner rod 1100 is not visible as it is positioned within the outer tube 1200 and the outer tube is flush with the anchor body 200. The outer tube 1200 may hold the anchor body 200 steady during insertion and engagement. The inner rod 1100 extends through the anchor body 200 and couples with the tissue grasper 300. The tissue grasper 300 is configured to be retracted toward the proximal end of the anchor body 200 from a first axial position to one or more intermediate axial positions relative to the anchor body 200, and ultimately, to a second axial position via advancement of the inner rod 1100, resulting from rotation of the deployment knob 1500. In some embodiments, the tissue grasper 300 is also configured for movement from an intermediate axial position back to a first starting position via retraction of the inner rod 1100 resulting from rotation of the deployment knob 1500 in an alternate direction. [0091] Various embodiments disclosed herein include methods of securing tissue to bone, including methods for securing soft tissue to bone in a simplified arthroscopic procedure. Using a tissue anchor 100 and inserter tool 1000, such as, for example, those described above, surgeons may be able to grab a soft tissue, position it within a bone hole, and secure it to bone using one surgical hole and one tool. Externalizing and whip stitching and/or suturing the tendon may not be necessary.

[0092] In one embodiment, illustrated in Figures 19A, 19B, and 19C, a biceps tenodesis procedure is performed to move the attachment of the biceps tendon 2200 from the shoulder joint to a position along the humerus bone 2000. When using one of the tissue anchors 100 described herein, the procedure requires drilling a bone hole 2400, positioning the tendon 2200 between arms of the tissue anchor 100, and inserting the tendon 2200 and tissue anchor 100 into the bone hole 2400 with the aid of an inserter tool (such as inserter tool 1000). In one embodiment, the procedure is performed arthroscopically. A percutaneous approach may be used in the alternative.

[0093] During the procedure, the implantation site is cleared of any soft tissue in the region of the desired bone hole using a bur or other suitable means. In one non-limiting embodiment, the shoulder preparation includes the method used by Richards and Burkhart in "A Biomechanical Analysis of Two Biceps Tenodesis Fixation Techniques" (Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 21, No 7, 2005: pp. 861-866), which is herein incorporated by reference in its entirety. The shoulder may undergo soft tissue dissection to the level of the rotator cuff. At this point, the supraspinatus tendon insertion is reflected by sharp dissection and the long head biceps (LHB) tendon is inspected for any evidence of pathology. The tendon of the LHB is then sharply incised, freeing it from its intra-articular origin at the superior aspect of the glenoid as well as dividing it at the musculotendinous junction so that the biceps tendon is a free segment. In other embodiments, other methods of shoulder preparation are used.

[0094] In some instances, the bone hole 2400 into which the tissue anchor will be inserted is made by drilling into the superior portion of the bicipital groove 2100 using a drill bit or suitably sized awl. Figure 19A shows an illustration of the bicipital groove 2100 and surrounding bone of the humerus 2000, along with the biceps tendon 2200 and biceps muscle 2300. The bicipital groove 2100 is a furrow on the upper part of the humerus occupied by the long head of the biceps and is also called the intertubercular groove. Depending on the softness of the bone, the position of reattachment, and the size of the anchor, the hole 2400 can be from 8 mm to over 30 mm deep. In one embodiment, a tissue anchor 100 with a length of 16 mm is used and placed in a bone hole 2400 that is 16-18 mm deep. In other embodiments, tissue anchors of other lengths are used, and they may be inserted into bone holes having different depths. The hole 2400 may be made in a supra-pectoral position or any other position suitable for the pathology of the tendon. In various embodiments, the tissue anchor 100 and bone hole 2400 are sized such that the proximal end of the tissue anchor 100 is situated flush with, or slightly recessed from, the cortical surface of the bone.

[0095] In some embodiments, a 7 mm-diameter drill bit is used; however, in other embodiments, a different sized drill bit can be used. In one embodiment, the bone hole 2400 can range from 5 mm to 9 mm in diameter. In other embodiments, the size of the bone hole will vary, as the size of the desired hole depends on the size of the anchor. In some embodiments, a PEEK tissue anchor 100 is used having a width of 7.25 mm at its widest point when in an unexpanded state. When expanded, the tissue anchor 100 of some embodiments has a maximum width of 10 mm. A tissue anchor 100 having such dimensions may be inserted into a bone hole 2400 having a 7.5 mm diameter. When expanded, the outwardly expandable portion may deploy into the surrounding subcortical or cortical bone and secure the position of the tissue anchor 100. The outwardly expandable portion may include angled protrusions, sharp edges, blunt proximal faces, or teeth used to provide greater resistance to removal of the anchor body than to insertion. In other embodiments, tissue anchors 100 of different widths, configurations, and/or materials may be used.

[0096] As shown in the illustrations of Figures 19B and 19C, once the bone hole 2400 is drilled, one embodiment of a method for attaching soft tissue to bone comprises: capturing a soft tissue 2200 using a tissue anchor 100, advancing the tissue anchor 100 into a bone hole 2400 with the aid of an inserter tool (such as, for example, inserter tool 1000), engaging the tissue anchor 100 with surrounding bone, and withdrawing the inserter tool 1000. In various embodiments of the method, the tissue anchor that is used comprises an anchor body 200 and a tissue grasper 300 with arms 310 that are configured to receive a soft tissue. One such tissue anchor is illustrated in Figure 20, which depicts a side view of one embodiment of an engaged tissue anchor 100 secured within a bone hole 2400.

[0097] Using a tissue anchor 100 comprising both an anchor body 200 and a tissue grasper 300 with arms 310, one method for attaching soft tissue to bone comprises retracting the arms 310 partially within an anchor body 200 so as to move the arms 310 together and thereby narrow the profile of the tissue anchor 100 for insertion of the tissue anchor 100 through a cannula into a shoulder (not shown). The method further comprises re- extending the arms 310 and capturing a soft tissue 2200 between the open arms 310. In some embodiments, the arms 310 are once again retracted partially within the anchor body 200 so as to move the arms 310 together and narrow the profile of the tissue anchor 100 for insertion into a bone hole 2400. The method further comprises advancing the tissue anchor 100 into a bone hole 2400. The method may include the additional steps of determining if tension on the tissue 2200 requires any adjustments, releasing the tissue 2200, if an adjustment is needed, by removing the arms 310 at least partially from the anchor body 200, repositioning the arms 310 around the soft tissue 2200, and again retracting the arms 310 at least partially into the anchor body 200 to recapture the soft tissue 2200 between the arms 310. The method additionally comprises further retracting the arms 310 into the anchor body 200 to expand the anchor body 200 and thereby engage the tissue anchor 100 with surrounding bone.

[0098] In some embodiments using an inserter tool 1000, partial retraction of the arms 310 into a lumen of the anchor body 200 can be accomplished by turning a deployment knob 1500 on the inserter tool 1000. This retraction partially closes the arms 310 around the soft tissue 2200. The soft tissue 2200 can then be moved, manipulated, and inserted into a bone hole 2400 through movement of the inserter tool 1000. Once positioned within the bone hole 2400, the tissue anchor 100 can be deployed to engage with the surrounding bone 2000. In some embodiments, the step of engaging the tissue anchor 100 with surrounding bone 2000 comprises turning the deployment knob 1500 of the inserter tool 1000 to further retract the arms 310 into the anchor body 200. This additional retraction causes a camming surface of a shaft 320 connected to the arms 310 to push against a plurality of tines 210 or other expandable feature on the anchor body 200. The tines 210 or other expandable feature(s) then expand into, and engage with, the surrounding bone. In the embodiment of Figure 20, the tines 210 of the tissue anchor 100 are positioned such that, upon further retraction of the shaft into the anchor body 200, the resulting expansion of the tines 210 causes the tissue anchor 100 to engage with subcortical bone 2001 and experience subcortical fixation. In an alternative embodiment, such as the embodiment of Figure 21, the portion of the anchor body 200 configured for expansion comprises an outwardly expandable proximal portion 205 of the anchor body 200. In some such embodiments, such as that shown in Figure 21, outward expansion of the proximal portion 205 results in anchor body expansion within the cortical layer 2002 of bone only. Thus, in some embodiments, securing the tissue anchor 100 within a bone may rely primarily on cortical fixation. In some embodiments, both cortical and subcortical fixation are employed.

[0099] In some embodiments of the method, the arms 310 are retracted until protrusions 340 on an outer perimeter of the arms 310 slide into, and engage with, open slots 230 positioned on the anchor body 200. This engagement of the teeth 340 with the open slots 230 acts as a locking mechanism, securing the arms 310 and soft tissue 2200 in a fixed position relative to the anchor body 200. In one embodiment utilizing the tissue anchor 100 and inserter tool 1000, when the inner tube 1 100 is advanced far enough that the tissue grasper 300 locks into place or cannot advance anymore, the face of the distal end of the outer tube 1200 is surface-to-surface with the face of the proximal end of the anchor body 200. In such an embodiment, when the inner rod 1100 withdraws further into the outer tube upon the continued rotation of the deployment knob 1500 and advancement of the actuator shaft 1400, the inner rod 1100 strips the threading from the tissue grasper 300 and the inserter tool 1000 detaches from the tissue anchor 100.

[0100] In some embodiments of the method, the tissue anchor 100 that is used comprises two flat, parallel sides 270 joined by two outwardly rounded sides 280. The width of the tissue anchor between the two flat sides 270 is smaller than the diameter between the two rounded sides 280 and smaller than the diameter of the bone hole 2400. Thus, in some embodiments, when the soft tissue 2200 is inserted into the bone hole 2400, the tissue folds around the tissue anchor 100 longitudinally, resting along the two flat sides 270 and within the gaps that exist between each flat side of the anchor body 200 and the perimeter of the bone hole.

[0101] It will be appreciated by those of skill in the art that the tissue anchor 100 and inserter tool 1000 provide a system for easy attachment of a soft tissue to bone. The tissue anchor 100 may be inserted into bone 2000 with minimal disruption of surrounding tissue. Only an access route having a diameter large enough to fit the outer tube 1200, the anchor body 200, and the two open arms 310 is required. Furthermore, the tissue anchor 100 can be securely attached to the bone without having to insert additional instrumentation into the site and without performing any cumbersome attachment maneuvers such as knot tying.

[0102] While this invention has been described in connection with what are presently considered to be practical embodiments, it will be appreciated by those skilled in the art that various modifications and changes may be made without departing from the scope of the present disclosure or the spirit of the invention. It will also be appreciated by those of skill in the art that parts mixed with one embodiment are interchangeable with other embodiments; one or more parts from a depicted embodiment can be included with other depicted embodiments in any combination. For example, any of the various components described herein and/or depicted in the Figures may be combined with, interchanged with, or excluded from other embodiments. With respect to the use of plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context. While the present disclosure has described certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Accordingly, the invention is limited only by the following claims and equivalents thereof.

Claims

WHAT IS CLAIMED IS:

1. A tissue anchor, comprising:

an anchor body comprising a distal end and a proximal end and defining a lumen; and

a tissue grasper configured to slideably fit within the lumen to move between at least a first axial position and second axial position,

wherein the tissue grasper comprises two arms coupled to a shaft, and wherein, when the tissue grasper is in the first axial position, the arms extend outward relative to the shaft, and when the tissue grasper is in the second axial position, the arms are retracted at least partially within the lumen and bent inward relative to their outward extension when the tissue grasper is in the first axial position.

2. The tissue anchor of Claim 1, wherein at least a portion of the anchor body comprises a first outwardly expandable portion which expands outward as the tissue grasper is transitioned to the second axial position.

3. The tissue anchor of Claim 2, wherein the shaft of the tissue grasper comprises a camming surface that contacts an inner surface of the first outwardly expandable portion as the tissue grasper is transitioned to the second axial position and thereby causes the first outwardly expandable portion to expand outward.

4. The tissue anchor of Claim 2, wherein the first outwardly expandable portion comprises a plurality of tines configured for displacement between an unexpanded position and an expanded position.

5. The tissue anchor of Claim 4, wherein each of the plurality of tines comprises a wedge having a first end and a second end, the wedge protruding into the lumen when the tines are in the unexpanded position, wherein the wedge is bendably coupled to the anchor body at the first end, and wherein the maximum protrusion of the wedge into the lumen is at the second end.

6. The tissue anchor of Claim 4, wherein each of the plurality of tines comprises an edge, point, ridge, or plurality of teeth.

7. The tissue anchor of Claim 2, wherein the first outwardly expandable portion includes a proximal portion of the anchor body, and wherein outward expansion of the proximal portion is greatest at the proximal end.

8. The tissue anchor of Claim 7, further comprising a second outwardly expandable portion located at a distal portion of the anchor body, wherein outward expansion of the distal portion is greatest at the distal end.

9. The tissue anchor of Claim 1, wherein the tissue grasper is configured to slide within the lumen between at least the first axial position, an intermediate axial position, and the second axial position.

10. The tissue anchor of Claim 9, wherein, in the intermediate axial position, the arms of the tissue grasper are reversibly positioned partially within the lumen.

11. The tissue anchor of Claim 1 , wherein at least one of the two arms comprises at least one tooth positioned on an outer side of the at least one of the two arms, and wherein the anchor body comprises at least one opening adapted to engage the at least one tooth when the tissue grasper is in the second axial position.

12. The tissue anchor of Claim 1, wherein the tissue anchor comprises polyether- ether-ketone (PEEK).

13. The tissue anchor of Claim 1, further comprising at least one tooth positioned on an inner side of at least one of the two arms.

14. The tissue anchor of Claim 1, wherein at least a portion of the distal end of the anchor body is concave.

15. The tissue anchor of Claim 14, further comprising a plurality of teeth positioned on the concave portion.

16. The tissue anchor of Claim 1, wherein the anchor body comprises at least one protrusion extending into the lumen and configured to engage with at least one depression on the shaft.

17. The tissue anchor of Claim 4, wherein the anchor body comprises two flat, parallel sides joined by two outwardly rounded sides.

18. The tissue anchor of Claim 17, wherein the plurality of tines are positioned on the two outwardly rounded sides.

19. The tissue anchor of Claim 2, wherein the anchor body has a maximum width of approximately 7 mm to approximately 9 mm when the tissue grasper is in the first axial position.

20. The tissue anchor of Claim 19, wherein the anchor body has a maximum width of approximately 9 mm to approximately 11 mm when the tissue grasper is in the second axial position.

21. The tissue anchor of Claim 20, configured to fit within a bone hole having a diameter that is larger than the maximum width of the anchor body in the first axial position and smaller than the maximum width of the anchor body in the second axial position.

22. The tissue anchor of Claim 1, wherein the anchor body has a length of approximately 16 mm to approximately 18 mm.

23. A method of attaching soft tissue to bone, comprising:

contacting a soft tissue with a tissue anchor, wherein the tissue anchor comprises an anchor body and two arms extending distally from the anchor body, wherein contacting the soft tissue with the tissue anchor comprises positioning the soft tissue between the two arms;

inserting the soft tissue and tissue anchor into a bone hole; and retracting the arms at least partially into the anchor body,

wherein retracting the arms moves the arms closer together to capture the tissue therebetween.

24. The method of Claim 23, further comprising:

releasing the soft tissue by extending the arms at least partially from the anchor body;

repositioning the arms relative to the soft tissue; and

retracting the arms at least partially into the anchor body to recapture the soft tissue between the arms.

25. The method of Claim 23, further comprising retracting the arms further into the anchor body to expand at least a portion of the anchor body and thereby secure the tissue anchor in the bone hole.

26. The method of Claim 25, wherein expanding at least a portion of the anchor body comprises outwardly bending a plurality of tines on the anchor body.

27. The method of Claim 23, further comprising forming the bone hole.

28. The method of Claim 27, wherein the bone hole is sized to receive the tissue anchor.

29. The method of Claim 23, wherein inserting the soft tissue and tissue anchor into the bone hole causes the soft tissue to longitudinally fold around the tissue anchor.

30. The method of Claim 29, wherein after folding the soft tissue around the tissue anchor, the soft tissue rests along one or more flat sides of the anchor body.

31. The method of Claim 23, wherein the soft tissue is captured and secured without using sutures, stitching or knots.

32. The method of Claim 23, wherein the method is conducted arthroscopically.