Tendon Interference Anchor

Abstract

The present disclosure provides an advantageous interference anchor. More particularly, the advantageous tendon interference anchor is configured to be inserted by impaction. The tendon interference anchor can include an anchor body having a proximal end, a distal end, a longitudinal axis, and an outer surface, and at least one protrusion extending outward from the outer surface of the anchor body in a direction non-parallel to the longitudinal axis of the anchor body. [Selection diagram] Figure 8

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application entitled "Tendon Interference Anchor," filed August 31, 2018 and assigned serial number 62 / 725,831, the contents of which are incorporated herein by reference.

[0002] TECHNICAL FIELD This disclosure relates generally to interference anchors, and more generally to tendon interference anchors inserted by impaction. [Background technology]

[0003] Conventional tendon interference anchors are attached to the desired fixation location (e.g., soft or hard tissue) by twisting. Conventional attachment methods subject the material at the desired fixation location to high torsional and tensile stresses. Furthermore, the constant sliding of the anchor threads along the tendon and bone creates friction, further increasing the likelihood of tendon tearing. Summary of the Invention [Problem to be solved by the invention]

[0004] In light of the foregoing, there is a need for effective anchors that reduce the potential for anatomical damage. Accordingly, there is interest in improved tendon interference anchors and related methods of use. These and other inefficiencies and areas for improvement are addressed and / or overcome by the presently disclosed assemblies, systems, and methods. [Means for solving the problem]

[0005] The present disclosure provides advantageous systems for improving fixation with soft tissue (e.g., tendons) and / or hard tissue (e.g., bone). In particular, the present disclosure is directed to systems / methods incorporating tendon interference anchors having advantageous protrusions (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof) for anchoring soft tissue, medical implants (e.g., bone plates) and / or hard tissue to hard tissue. More specifically, exemplary systems / methods are disclosed that include an anchor system having an anchor body and protrusions for securing the anchor to a desired fixation location (e.g., a desired bone location). The disclosed anchor system is configured to be advanced and secured to a desired fixation location by impaction.

[0006] In an exemplary embodiment, the present disclosure provides an anchor system advantageous for improving fixation between various anatomical surfaces and / or structures (e.g., soft tissues, hard tissues, and / or medical implants). The disclosed anchor system includes an anchor body having a proximal end, a distal end, a longitudinal axis, an outer surface, and at least one protrusion (e.g., one or more splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof) for securing the anchor system relative to a desired fixation location. The outer surface of the anchor body may include at least one protrusion extending outward therefrom in a direction non-parallel to the longitudinal axis of the anchor body. Additionally, the at least one protrusion may extend radially from the longitudinal axis.

[0007] The disclosed anchor system may be advantageously inserted into the desired fixation location by impaction. Depending on the type of protrusion, the anchor system may rotate slightly during impaction. In some embodiments, the rotation aids in impaction to further secure the anchor against the surrounding anatomical surfaces and / or structures (e.g., soft and hard tissues). In such cases, the impaction force is understood to be the primary and substantial driving force when inserting / advancing the anchor into the desired fixation location. In other embodiments, the impaction force and the resulting rotational force act in concert to insert / advance the anchor into the desired fixation location.

[0008] In an exemplary embodiment, an advantageous anchor system includes an anchor body having a proximal end, a distal end, a longitudinal axis, an outer surface, and at least one helical spline associated in whole or in part with the outer surface of the disclosed anchor body. In an exemplary embodiment, the disclosed anchor may include five or six external helical splines with a helix angle ranging from about 180 degrees to about 360 degrees. However, more or less external helical splines may be utilized without departing from the scope or spirit of the present disclosure. The disclosed anchor system may further include a flared head to limit the depth to which the anchor system may be inserted and / or moved relative to a desired fixation location. The disclosed anchor system may further include at least one (or both) of a cannula hole and a cross hole. The disclosed hole(s) may allow for an in situ curable polymer to enter and / or pass through the anchor body.

[0009] In another exemplary embodiment, an advantageous anchor system includes an anchor body having a proximal end, a distal end, a longitudinal axis, an outer surface, and at least one helical spline associated in whole or in part with the outer surface of the disclosed anchor body. The disclosed anchor body may further include a plurality of projections extending in whole or in part from one or more of the disclosed splines. The disclosed anchor system may further include at least one (or both) of a cannula hole and a cross hole. A four-strand graft previously secured to the femur may be pulled through the cannula hole. The strands may be separated and positioned within each quadrant of the disclosed anchor.

[0010] In yet another embodiment, an advantageous anchor system includes an anchor body having a proximal end, a distal end, a longitudinal axis, an outer surface, and at least one spline associated in whole or in part with the outer surface of the disclosed anchor body. The disclosed spline(s) can function, among other things, to vary the amount of possible engagement with the disclosed fixation locations, such that at one location along the anchor body, the disclosed spline(s) can engage opposing hard / soft tissues more than at another location along the anchor body. The disclosed anchors may further include a plurality of protrusions disposed at least in part along one or more splines. The disclosed anchor system may further include at least one (or both) of a cannula hole and a cross hole. In some cases, a four-strand graft already secured to the femur can be pulled through the cannula hole. The strands are disposed separately within each quadrant of the indicated anchor body.

[0011] Any combination or permutation of the features, functions and / or embodiments as disclosed herein is contemplated. Additional advantageous features, functions and applications of the disclosed systems, methods and assemblies of the present disclosure will become apparent from the following description, particularly when read in conjunction with the accompanying drawings. All references cited in this disclosure are incorporated herein by reference in their entirety.

[0012] Features and aspects of the embodiments are described below with reference to the accompanying drawings, in which elements are not necessarily shown to scale.

[0013] Exemplary embodiments of the present disclosure are further described with reference to the accompanying drawings, in which it is noted that the various features, steps and combinations of features / steps described below and illustrated in the drawings can be arranged and organized in various ways to result in embodiments that still fall within the scope of the present disclosure.

[0014] To assist those skilled in the art in making and using the disclosed assemblies, systems and methods, reference is made to the accompanying drawings. [Brief description of the drawings]

[0015] [Figure 1A] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 1B] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 2A] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 2B] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 3A] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 3B] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 3C] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 3D] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 4] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Diagram 5]FIG. 13 is a schematic diagram illustrating an assembly view of an exemplary tendon interference anchor and desired fixation location according to the present disclosure. [Figure 6A] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 6B] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 7] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 8] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; [Figure 9] 1A-1C are schematic diagrams illustrating an exemplary tendon interference anchor according to the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The exemplary embodiments disclosed herein illustrate advantageous systems for improving fixation with soft tissue (e.g., tendons) and / or hard tissue (e.g., bones). However, it should be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Thus, the details disclosed herein regarding the exemplary assemblies / methods of manufacture and methods / techniques associated with the assembly and use should not be construed as limiting, but merely as a basis for teaching one of ordinary skill in the art how to make and use the advantageous assemblies / systems of the present disclosure.

[0017] The present disclosure provides an advantageous system / method of an exemplary tendon interference anchor having improved protrusions for anchoring soft tissue, medical implants (e.g., bone plates) and / or hard tissue to hard tissue. More specifically, an exemplary system / method is disclosed that includes an anchor system having an anchor body and protrusions for securing the anchor to a desired bone location. The disclosed anchor system is configured to be substantially impacted into a desired bone location, particularly when the primary mode of insertion is impaction. As used herein, the tendon interference anchor may be referred to as an "interference anchor," an "anchor system," or an "anchor."

[0018] The disclosed tendon interference anchor may include an anchor body and at least one protrusion (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof). The at least one protrusion is at least partially associated with an outer surface of the anchor body. The anchor body and the at least one protrusion may be manufactured as a single component or may be two separate components assembled together to provide the appearance / function of a single component. This disclosure is not intended to be limiting, and the use of "anchor body" and "protrusion" are merely descriptive, and thus manufacturing variations of both are contemplated unless otherwise specified.

[0019] The disclosed anchors have a proximal end, a distal end, and a longitudinal axis. The distal end may include at least one element to aid in insertion of the anchor into a desired fixation location. For example, the anchor may include a substantially conical distal tip. However, the distal tip may be manufactured in a variety of shapes, including cylindrical, spherical, and / or with a loop adapted for retention of at least one suture or cable. The disclosed anchors may have an anchor body having a substantially circular cross-section. However, the disclosed anchor bodies are not limited to the disclosed cross-sections and may utilize a variety of shapes (e.g., oval, elliptical, quadrilateral, triangular, or combinations thereof).

[0020] The disclosed anchor system may further include at least one of a cannulated hole and a cross hole. In some cases, a four-strand graft already secured to the femur can be pulled through the cannulated hole. The strands may be separated and positioned within each quadrant of the anchor shown. The disclosed anchor system may further include an element (e.g., a nail head) positioned against the proximal end that is at least partially larger than the cross section of the anchor system. However, in other cases, the element may not exceed the cross section of the anchor system in all directions. The disclosed anchor system may be manufactured to any desired length as would be understood by one of skill in the art based on the intended use.

[0021] The disclosed anchors can be introduced into a desired fixation location (e.g., soft and / or hard tissue). As used herein, the desired fixation location may be a desired location located proximate to an anatomical surface or may be at least a partial hole into which the disclosed anchor can be introduced. In one embodiment, the desired fixation location includes a hole having a diameter substantially similar to the diameter of the disclosed anchor body. As previously mentioned, the disclosed anchors can be introduced into a desired fixation location by impaction. Depending on the desired protrusion format and orientation, the disclosed anchors can be rotated during impaction. However, with respect to the primary insertion of the anchor, rotation is an aid to impaction. Rotation as a secondary form of insertion helps to secure the disclosed anchors into a desired fixation location without falling into the disclosed pitfalls of twisted insertion.

[0022] During operation, an impinging force may be applied directly / indirectly to the proximal end of the disclosed anchor. In an exemplary embodiment where the disclosed anchor includes a helical protrusion, the disclosed anchor may rotate slightly at the desired fixed position during impingement. However, in another exemplary embodiment where the disclosed anchor includes a non-helical protrusion, the disclosed anchor may be impingingly inserted at the desired fixed position without any auxiliary rotation. The desired method depends on the application.

[0023] The disclosed anchors may be at least partially fabricated from a biodegradable citrate-based composite. The disclosed anchors may be bioabsorbable. The disclosed anchor systems comprise a composite of citric acid and / or citrate and at least one C2-C 20 More specifically, the disclosed anchoring system may be formed at least in part from a polycondensation product of citric acid and / or citrate and at least one C4-C alkanediol. 12 The citrate-based (co)polyester may be at least partially formed from a polycondensation product with an alkanediol. In certain embodiments, the citrate-based (co)polyester may be poly(1,8-octanediol citrate). In certain embodiments, the disclosed anchor may be at least partially formed from a composite material comprising a citrate-based polymer and a bioceramic. In certain embodiments, the bioceramic is selected from the group comprising hydroxyapatite and beta-tricalcium phosphate. The citrate-based polymer and the bioceramic may be present in the composite material in any suitable weight ratio relative to one another.

[0024] Examples of tendon interference anchors and anchoring systems / methods according to the present disclosure are illustrated in Figures 1-9.

[0025] 1A-2B, an exemplary tendon interference anchor 10, 100 includes an anchor body 12 and at least one protrusion 18, 102 (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof). The anchor body 12 may be substantially solid, partially solid, or substantially hollow. The at least one protrusion 18, 102 is at least partially associated with an outer surface of the anchor body 12. The anchor 10, 100 has a proximal end 14 and a distal end 16 and a longitudinal axis. The distal end 16 may include at least one element to aid in insertion of the anchor 10 into a desired fixation location. For example, the anchor 10, 100 may include a substantially conical distal tip 20. The anchor body 12 may have a substantially circular cross-section, as illustrated in FIGS. 1B and 2B.

[0026] In an exemplary embodiment, at least one of the protrusions 18, 102 may be a spline. More specifically, the disclosed spline 18, 102 may be a helix having a twist angle ranging from about 180 degrees to about 360 degrees. The disclosed helical spline 18, 102 may begin proximate the proximal end 14 and end proximate the distal end 16. In some examples, the disclosed helical spline 18, 102 may twist from about the proximal end 14 to about the distal end 16. The spline 18, 102 may extend outward from the outer surface of the anchor body 12 in a direction non-parallel to the longitudinal axis of the anchor body 12. As illustrated in FIG. 1A, the helical spline 18 has a twist angle of about 180 degrees. Meanwhile, as illustrated in FIG. 2A, the helical spline 102 has a twist angle of about 360 degrees. The disclosed anchor 10, 100 may include five helical splines 18 as shown in FIG. 1B, or six helical splines 102 as shown in FIG. 2B. Although shown with five helical splines 18 and a helix angle of about 180 degrees and six helical splines 102 and a helix angle of about 360 degrees, some variations are possible, as shown in FIG. 3 described below. The design of the at least one protrusion 18, 102 may be optimized depending on the desired fixation location (e.g., soft tissue or hard tissue). In particular, the at least one protrusion 18, 102 may be configured and adapted to be gripped in the desired fixation location and to resist (or substantially resist) movement in at least one direction, for example, to resist (or substantially resist) rotational, translational, and / or longitudinal movement.

[0027] The design of the splines 18, 102 can be substantially symmetrical (e.g., similar to V-thread, round V-thread, square thread, acme thread, knuckle thread profiles, among others) such that the bearing (i.e., engagement) surface 106 and the opposing threaded surface 108 have a substantially similar angle (i.e., spline / thread angle) relative to the longitudinal axis of the anchor body 12 (see, e.g., FIG. 2B). However, it should be understood that the spline angles may be varied without departing from the spirit / scope of the present disclosure. Thus, the spline angles are not limited to angles used in typical applications (e.g., connections with metal, wood, plastic, or bolt / nut configurations).

[0028] Alternatively, the design of the splines 18, 102 may be biased (e.g., downwardly biased) to limit movement of the engaged anatomical surface(s) (e.g., tendon) (see, e.g., FIG. 1B). The bearing surface (i.e., engagement surface) 24 may be substantially perpendicular (or slightly biased / inclined) with respect to the longitudinal axis of the anchor body 12. The opposing threaded surface 26 may be at a standard angle (e.g., 30, 45, 60, as known to those skilled in the art). The designation of the bearing surface 24, 106 and the opposing threaded surface 26, 108 depends on the winding direction of the helical splines 18, 102.

[0029] In the present example, the helical splines 18, 102 are described as having a right-handed configuration. However, a left-handed configuration is also possible. In such a case, the bearing surface 24, 106 and the opposing threaded surface 26, 108 are interchanged. The depth of the splines 18, 102, defined as the distance between the outer surface 22, 104 of the splines 18, 102 and the outer surface of the anchor body 12, may at least partially affect the level of engagement between the anchor 10, 100 and the desired fastening location. As with the spline angle, the spline depth may vary depending on the application and the desired fastening location.

[0030] As previously mentioned, the five helical spline anchor and the six helical spline anchor may each have a twist angle ranging from about 180 degrees to about 360 degrees. As previously illustrated, and reproduced as FIG. 3A for ease of comparison, anchor 10 has five helical splines 18 having a twist angle of about 180 degrees. FIG. 3B utilizes a similar five helical spline anchor 10, but with a twist angle of about 360 degrees. Further, as previously illustrated, and reproduced as FIG. 3D for ease of comparison, anchor 100 has six helical splines 102 having a twist angle of about 360 degrees. FIG. 3C utilizes a similar six helical spline anchor 100, but with a twist angle of about 180 degrees.

[0031] In another exemplary embodiment, as illustrated in FIG. 4, the tendon interference anchor 200 includes an anchor body 202 and at least one protrusion 208 (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof). The anchor 200 has a proximal end 204, a distal end 206, and a longitudinal axis. The anchor body 202 may be substantially solid, partially solid, or substantially hollow. The at least one protrusion 208 is at least partially associated with an outer surface of the anchor body 202. In some embodiments, the at least one protrusion 208 may be a spline. In one example, as illustrated in FIG. 4, the anchor 200 includes six splines. However, as described in more detail above, five splines may be utilized. More specifically, the disclosed spline 208 may be a helix having a twist angle ranging from about 180 degrees to about 360 degrees. In some examples, the disclosed helical spline 208 may twist from about the proximal end 204 to about the distal end 206 .

[0032] The proximal end 204 may include an attachment element (e.g., a head) 212 configured and adapted to ensure that at least a portion of the anchor 200 remains adjacent to an opening at a desired fixation location. More specifically, the element 212 may ensure that at least a portion of the anchor 200 is outside, flush, or slightly recessed (e.g., countersink or counterbore) into the opening at the desired fixation location. The element 212 may have a cross-section that is at least partially larger than the combined cross-section of the at least one protrusion(s) 208 and the anchor body 202. Even more specifically, in examples where the anchor 200 connects two or more bone portions, the element 212 may ensure that at least a portion of the anchor 200 is outside, flush, or slightly recessed (e.g., countersink or counterbore) into one of the bone portions, as described in more detail below with reference to FIG. 5.

[0033] In one example, as shown in FIG. 4, the element 212 may resemble the head of a nail, screw, or the like. The cross section of the element 212 may be sized such that at least a portion of the element 212 does not extend beyond the cross section of the protrusion 208. For example, the anchor body 202 may be T-shaped, with the vertical portion of the "T" being the anchor body 202 and the cross portion disposed vertically above the anchor body 202 being the element 212. The distal end 206 may include at least one element to aid in the insertion of the anchor 200 into the desired anchoring location. For example, the anchor may include a substantially conical distal tip 210. The anchor body 202 may have a substantially circular cross section, as illustrated in FIGS. 1B and 2B. The product depicted in FIGS. 1A-3D may further incorporate the element 212, and conversely, the anchor 200 may further incorporate the features described above with reference to FIGS. 1A-3D. It is therefore to be understood that the disclosure is not strictly defined by the figures, and the use of features of the other figures is contemplated and encouraged.

[0034] In another exemplary embodiment, as illustrated in FIGS. 6A-6B, a tendon interference anchor 300 includes an anchor body 302 and at least one protrusion 308 (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof). The anchor 300 has a proximal end 304, a distal end 306, and a longitudinal axis. The anchor body 302 may be substantially solid, partially solid, or substantially hollow. The at least one protrusion 308 is at least partially associated with an outer surface of the anchor body 302. In some embodiments, the at least one protrusion 308 may be a spline. In one example, as illustrated in FIG. 6A, the anchor 300 includes six splines. However, as described in more detail above, five splines may be utilized. More specifically, the disclosed spline(s) 308 may be helical having a helix angle ranging from about 180 degrees to about 360 degrees. In some examples, the disclosed helical spline 308 may twist from about the proximal end 304 to about the distal end 306.

[0035] The anchor 300 may include at least one hole (e.g., a cannulated hole and a cross hole). In an exemplary embodiment, the anchor 300 may include at least one cross hole 314 and at least one cannulated hole 316. The cross hole 314 may extend at least partially through the anchor body 302 at a desired non-parallel angle to the longitudinal axis of the anchor 300. For example, as shown in FIGS. 6A-6B, the cross hole(s) 314 may be substantially perpendicular to the longitudinal axis of the anchor 300. The anchor 300 may include two cross holes 314. As shown, the two cross holes 314 may be disposed substantially perpendicular to the longitudinal axis of the anchor 300 and substantially perpendicular to each other. However, it should be understood that any orientation may be utilized. For example, the at least two cross holes 314 may be disposed at different positions along the longitudinal axis of the anchor 300. The anchor 300 may include a cannula hole 316 extending at least partially through the anchor body 300. For example, the cannula hole 316 may extend from the proximal end through at least a portion of the anchor body 302. In one example, the cannula hole 316 may extend along a longitudinal axis of the anchor 300. The cannula hole 316 may at least partially intersect with the cross hole 314, as shown in FIG. 6B.

[0036] In an exemplary embodiment, the cannula hole 316 extends from the proximal end of the anchor 300 at least partially through the anchor body 302 along the longitudinal axis of the anchor 300. At least two cross holes 314 may intersect the cannula hole 316. The cross holes 314 may be substantially perpendicular to the cannula hole 316 or may be substantially perpendicular to each other. The cross holes 314 and the cannula hole 316 may facilitate interdigitation between the in situ polymeric material (e.g., low viscosity) and the surrounding anatomical structure. In one example, the anchor 300 may be inserted into a desired fixation location as described above. Once inserted, the in situ polymeric material may be introduced through the cannula hole 316. The in situ polymeric material flows through the cannula hole 316 and out of the at least one cross hole 314, thereby interdigitating with the surrounding anatomical structure in the desired fixation location. In another example, the in situ polymeric material may be introduced into the desired fixation location prior to insertion of the anchor 300. During installation, the anchor 300 compresses the in situ polymer material within the desired fixation location so that the in situ polymer material interdigitates the desired fixation location with the anchor 300 (e.g., at least partially through the cross hole 314 and / or the cannula hole 316).

[0037] In another example, the anchor 300 may further include an attachment element 312 (e.g., a head) configured and adapted to ensure that at least a portion of the anchor 300 remains adjacent to an opening at a desired fixation location. The element 312 may be associated with the proximal end 304. More specifically, the element 312 may ensure that at least a portion of the anchor 300 is outside, flush, or slightly recessed (e.g., countersink or counterbore) the opening at a desired fixation location. The element 312 may have a cross-section that is at least partially larger than the combined cross-section of at least one protrusion 308 and the anchor body 302. Even more specifically, in an example where the anchor 300 connects two or more bone portions, the element 312 may ensure that at least a portion of the anchor 300 is outside, flush, or slightly recessed (e.g., countersink or counterbore) one of the bone portions (see, e.g., FIG. 5). The cannula hole 316 may extend at least partially through the element 312. Distal end 306 may include at least one feature to aid in insertion of anchor 300 into a desired fixation location. For example, the anchor may include a substantially conical distal tip 310. Anchor body 302 may have a substantially circular cross-section.

[0038] In another exemplary embodiment, as illustrated in FIGS. 7 and 8, a tendon interference anchor 400 includes an anchor body 402 and at least one protrusion 408 (e.g., spline, I-beam, barb, serration, thread, rib, ridge, tine, tooth, wedge, fin, groove, and any combination thereof). The anchor 400 has a proximal end 404, a distal end 406, and a longitudinal axis. The anchor body 402 may be substantially solid, partially solid, or substantially hollow. The at least one protrusion 408, 452 is at least partially associated with an outer surface of the anchor body 402. In some embodiments, the at least one protrusion 408 may be a spline. In particular, the anchor 400 may include four protrusions 408, 452 (e.g., splines). More particularly, the disclosed spline(s) 408 may be a helix having a twist angle ranging from about 1 degree to about 360 degrees. In an exemplary embodiment, the disclosed spline(s) 408, 452 may have a twist angle of about 12.9 degrees. The splines 408 may extend outward from the outer surface of the anchor body 402 in a direction non-parallel to the longitudinal axis of the anchor 400. In some examples, the disclosed helical splines 408 may twist from about the proximal end 404 to about the distal end 406. Between each spline 408 is a groove 409. The groove 409 is defined by adjacent splines 408, 452 and the anchor body 402.

[0039] The anchor 400 may further include at least one notch 410 at least partially surrounding the anchor body 402. The notch 410 may be designed such that removal of the anchor 400 from the desired fixation location is more difficult than during insertion of the anchor 400. The notch 410 may include a portion angled with respect to the longitudinal axis of the anchor 400. In particular, the notch 410 includes a portion that is substantially perpendicular to the longitudinal axis of the anchor 400. In an exemplary embodiment, the anchor includes four notches 410 at least partially surrounding the anchor body 402. The notches 410 may facilitate interdigitation between the in situ polymeric material (e.g., low viscosity) and the surrounding anatomical structure. In one example, an in situ polymeric material may be introduced into the desired fixation location prior to insertion of the anchor 400 into the desired fixation location. During installation of anchor 400, anchor 400 compresses the in situ polymer material into the desired fixation location such that the in situ polymer material interdigitates anchor 400 with the desired fixation location (e.g., at least partially with respect to notch 410).

[0040] The anchor body 402 may further include a hole 416 extending at least partially from the proximal end 404 to the distal end 406. In an exemplary embodiment, the hole 416 extends from the proximal end 404 to the distal end 406, such that the hole 416 is a through hole. The hole 416 may extend at least partially from the proximal end 404 to the distal end 406 along the longitudinal axis of the anchor 400. In one embodiment, as described above, the hole 416 may facilitate interdigitation between the in situ polymeric material and the surrounding anatomical structure. In another embodiment, the hole 416 may be at least partially engaged with a graft (not shown). In particular, if the graft (e.g., a four-strand graft) is already secured to a desired fixed location (e.g., the femur), the graft may be pulled through the hole 416. The strands of the graft may be placed separately into their respective grooves 409. While the graft is pulled to ensure proper tension, anchor 400 is inserted (eg, by impaction) into the desired fixation location.

[0041] The proximal end 404 may include an attachment element (e.g., a head) configured and adapted to ensure that at least a portion of the anchor 400 remains adjacent to an opening at a desired fixation location. More specifically, the attachment element may ensure that at least a portion of the anchor 400 is outside, flush, or slightly recessed (e.g., countersink or counterbore) the opening at a desired fixation location. The element may have a cross-section that is at least partially larger than the combined cross-section of at least one protrusion 408 and the anchor body 402. Even more specifically, in an example where the anchor 400 connects two or more bone portions, the element may ensure that at least a portion of the anchor 400 is outside, flush, or slightly recessed (e.g., countersink or counterbore) one of the bone portions. The distal end 406 may include at least one element to aid in insertion of the anchor 400 into a desired fixation location. For example, the anchor may include a substantially conical distal tip 412. The conical distal tip 412 may further include a surface 414, which may facilitate separation of at least one strand from a graft (e.g., a four-strand graft). In certain instances, the surface 414 may be partially angled and slightly concave. In one embodiment, the surface 414 may separate two strands from a four-strand graft. The separated strands may be disposed within the grooves 409 of the respective projections 408, 452, as previously described. The anchor body 402 may have a substantially circular cross-section.

[0042] In another exemplary embodiment, as illustrated in detail in FIG. 8, the disclosed protrusion may further include at least one additional protrusion (e.g., barbs, knurls, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof) disposed thereon. Anchor 450 is a variation of anchor 400, with similar features being labeled with the same reference numbers. Anchor 450 includes at least one protrusion 452 (e.g., splines, I-beams, barbs, knurls, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof) as described above. Protrusion 452 may be a helical spline. Disposed on the outer surface of protrusion 452 is at least one second protrusion 454 (e.g., barbs, knurls, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof). The protrusions 452 may extend outwardly from the outer surface of the anchor body 402 in a direction non-parallel to the longitudinal axis of the anchor body 402. In some examples, the disclosed helical spline 452 may twist from about the proximal end 404 to about the distal end 406. In one example, multiple second protrusions 454 may be disposed along the spline 452. As outlined above, a variety of second protrusions 454 may be used depending on the desired fixation location (e.g., cartilage and / or bone).

[0043] In yet another exemplary embodiment, as shown in FIG. 9 , a tendon interference anchor 500 includes an anchor body 502 and at least one protrusion 508 (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof). The anchor 500 has a proximal end 504, a distal end 506, and a longitudinal axis. The anchor body 502 may be substantially solid, partially solid, or substantially hollow. The at least one protrusion 508 is at least partially associated with an outer surface of the anchor body 502. In one example, a plurality of protrusions 508 are disposed on the outer surface of the anchor body 502. The protrusions 508 may be configured such that a cross-sectional diameter of the anchor 500 varies at different locations along the longitudinal axis of the anchor 500. For example, a central portion of the anchor 500 may have a larger cross-sectional diameter than at least one end of the anchor 500. Such dimensional variations provide different levels of engagement with the desired fixed location depending on the location along the longitudinal axis of the anchor 500. The anchor 500 may further include additional protrusions 510 (e.g., splines, I-beams, barbs, serrations, threads, ribs, ridges, tines, teeth, wedges, fins, grooves, and any combination thereof) that may partially cover the outer surface of the anchor body 502. For example, as described above, the additional protrusions 510 may be utilized to create a larger cross section. The protrusions 508, 510 may extend outward from the outer surface of the anchor body 502 in a direction non-parallel to the longitudinal axis of the anchor body 502.

[0044] The anchor 500 may further include a groove 512 defined by side walls 514, 516. The anchor body 502 may further define at least a portion of the depth of the groove 512. The groove 512 may be disposed proximate the distal end 506. At least a portion of the side walls 514, 516 and / or the anchor body 502 may be rounded. The groove 512 may be sized to receive at least one graft (e.g., a four-strand graft). In particular, a graft (not shown) may be disposed proximate the groove 512 while the anchor 500 is inserted (e.g., by impaction) into the desired fixation location. The anchor 500 may be inserted into the desired fixation location by impaction alone. The protrusions 508, 510 may at least partially secure the anchor 500 in the desired fixation location, and the groove 512 may provide a location for the graft (not shown) to rest.

[0045] Although the present disclosure has been described with reference to illustrative examples, the present disclosure is not limited by or to such illustrative examples, but rather, various modifications, improvements, and / or alternative examples may be employed without departing from the spirit or scope of the present disclosure.

Claims

1. an anchor body (12) having a longitudinal axis, a proximal end (14), a distal end (16), and an outer surface having a smooth circumferential surface in a longitudinal direction of the longitudinal axis and defining an outer diameter about the longitudinal axis; A plurality of splines (18, 102,) disposed on an outer surface of the anchor body (12) and extending in a direction non-parallel to the longitudinal axis of the anchor body (12). A biodegradable tendon interference anchor (10, 100) comprising: each of the plurality of splines (18, 102) extends from an imaginary plane intersecting the longitudinal axis of the anchor body at the proximal end of the anchor body to a distal end of the anchor body; each of the plurality of splines (18, 102) defines a spline depth, the distance between an outer surface of the anchor body and an outer surface of the spline (22, 104); an outer diameter of the proximal end (14) corresponds to an outer surface (22, 104) of the spline and a depth of the spline extends inwardly relative to the outer diameter of the proximal end; The anchor (10, 100) is configured and adapted to at least partially fit into a desired fixation location; Biodegradable tendon interference anchor (10,100).

2. 10. The biodegradable tendon interference anchor (10,100) of claim 1, wherein each of the plurality of splines (18,102) is twisted from about a proximal end to about a distal end of the anchor body.

3. 2. The biodegradable tendon interference anchor (10, 100) of claim 1, wherein the plurality of splines (18, 102) includes five helical splines disposed on an outer surface of the anchor body (12, 202, 302).

4. 2. The biodegradable tendon interference anchor (10, 100) of claim 1, wherein the plurality of splines (18, 102) includes six helical splines disposed on an outer surface of the anchor body (12, 202, 302).

5. 10. The biodegradable tendon interference anchor of claim 1, wherein each of the plurality of splines has a twist angle of about 180 degrees to about 360 degrees.

6. An anchor body (202, 302) having a longitudinal axis, a proximal end (204, 304) having a smooth circumferential surface when viewed in a longitudinal direction of the longitudinal axis and defining an outer diameter centered on the longitudinal axis, a distal end (206, 306), and an outer surface; A plurality of splines (208, 308) disposed on an outer surface of the anchor body (202, 302) and extending in a direction non-parallel to the longitudinal axis of the anchor body (202, 302). A biodegradable tendon interference anchor (200, 300) comprising: the proximal end (204, 304) includes a mounting element (212, 312) having a cross-section at least partially greater than the combined cross-section of the at least one spline (208, 308) and the anchor body (202, 302); each of the plurality of splines (208, 308) extends from an imaginary plane intersecting the longitudinal axis of the anchor body at the proximal end of the anchor body to a distal end of the anchor body; each of the plurality of splines (208, 308) defines a spline depth that is a distance between an outer surface of the anchor body and an outer surface of the spline; The tendon interference anchor (200, 300) is configured and adapted to at least partially fit into a desired fixation location; Biodegradable tendon interference anchors (200, 300).

7. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, further comprising a distal tip (20, 210, 310) relative to the distal end (16, 206, 306), wherein the distal tip is selected from the group consisting of a conical tip, a cylindrical tip, a spherical tip, a looped tip, and any combination thereof.

8. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, wherein the anchor body (12, 202, 302) is at least partially formed from a citrate-based (co)polyester.

9. The citrate-based (co)polyester is a mixture of citric acid and / or citrate and at least one C 4 ~C 12 9. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 8, which is a polycondensation product with an alkanediol.

10. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 9, wherein the citrate-based (co)polyester is poly(1,8-octanediol citrate).

11. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, wherein the anchor body (12, 202, 302) is at least partially formed from a composite material including a citrate-based polymer and a bioceramic.

12. 12. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 11, wherein the bioceramic is selected from the group consisting of hydroxyapatite and beta-tricalcium phosphate.

13. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, further comprising a cannula hole (316) extending from the proximal end (14, 204, 304) to the distal end (16, 206, 306), the cannula hole being substantially parallel to the longitudinal axis.

14. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, further comprising at least one cross hole (314) extending from an outer surface of the anchor body (12, 202, 302) in a direction non-parallel to the longitudinal axis.

15. 13. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, wherein at least one of the distal end (16, 206, 306), the anchor body (12, 202, 302), and the proximal end (14, 204, 304) is configured and dimensioned to receive at least one graft.

16. 10. The biodegradable tendon interference anchor (10, 100, 200, 300) of claim 1 or 6, wherein the combined diameter of the anchor body (12, 202, 302) and the plurality of splines (18, 102, 208, 308) is different at at least two positions along the longitudinal axis of the anchor body (12, 202, 302).

17. An anchor body (12) having a longitudinal axis, a proximal end (14) having a smooth circumferential surface along the longitudinal axis and defining an outer diameter about the longitudinal axis, a distal end (16), and an outer surface; A plurality of splines (18, 102) disposed on an outer surface of the anchor body (12) and extending in a direction non-parallel to the longitudinal axis of the anchor body (12). A biodegradable tendon interference anchor (10, 100) comprising: each of the plurality of splines (18, 102) extends from an imaginary plane intersecting the longitudinal axis of the anchor body at the proximal end of the anchor body to a distal end of the anchor body; each of the plurality of splines (18, 102) defines a spline depth, the distance between an outer surface of the anchor body and an outer surface of the spline (22, 104); each of the plurality of splines (18, 102) twisting from the proximal end (14) to the distal end (16) of the anchor body (12) at a twist angle of about 180 degrees to about 360 degrees; an outer diameter of the proximal end (14) corresponds to an outer surface (22, 104) of the spline and a depth of the spline extends inwardly relative to the outer diameter of the proximal end; The anchor (10, 100) is configured and adapted to at least partially fit into a desired fixation location; Biodegradable tendon interference anchor (10,100).

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