Dynamic fixation implants and methods of use

Abstract

An implant and related methods for achieving dynamic fixation are disclosed. The implant includes a head portion at a proximal end of the implant, the head portion including external threads and a first axial throughbore, and an anchor portion at a distal end of the implant, the head portion including external threads and a second axial throughbore communicating with the first axial throughbore. The implant further includes a flexible restraint member extending within the first and second axial throughbore, the flexible restraint member having a first end coupled to the head portion and a second end coupled to the anchor portion. At least one of the head portion and the anchor portion forms a breakaway portion with aligned inner and outer circumferential grooves configured to concentrate stress therein, such that the breakaway portion breaks under forces acting on the implant, separating the head portion and the anchor portion.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 899,559, filed September 12, 2019, entitled "Dynamic Fixation Implant and Method of Use," the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to general podiatric and orthopedic procedures related to ligament fixation. More particularly, although not exclusively, the present disclosure relates to devices, systems, and methods for achieving dynamic ligament fixation. [Background technology]

[0003] Syndesmotic injuries are the result of trauma (not specific to sports injuries) and can occur as pure ligamentous injuries or in combination with ankle fractures. These ligaments can become disrupted, separated, or damaged, requiring semi-constrained approximation and immobilization during healing without the need for a second surgical procedure, such as removal of rigid fixation screws. The current standard of care for syndesmotic injuries involves either rigid fixation with screws or a tethered restraint across the entire width of the ankle.

[0004] While more rigid base fixations are easier to implant and stabilize the joint, they do not allow all of the motion normally present physiologically, which limits the patient's range of motion and unpredictable screw failure points can result in damage to existing bone and patient pain.

[0005] Currently available tethered restraints allow joint movement but, by spanning the full width of the ankle, fail to mimic the intact ligamentous structure of the syndesmosis in terms of attachment location and distance between the fibula and tibia. However, tethered restraints result in a necessary reduction in structural strength due to the surgical procedure for implantation, which involves drilling holes through both the tibia and fibula, which are left unfilled with structural material (e.g., metal screws).

[0006] Thus, new and improved devices, systems and methods for achieving ligament fixation are needed to overcome the above-mentioned deficiencies of currently available solutions for addressing syndesmosis injuries. Summary of the Invention [Means for solving the problem]

[0007] FIELD OF THE DISCLOSURE The present disclosure relates to implants and methods for use in fixation. The implants and methods can be configured to achieve dynamic ligament fixation.

[0008] In one aspect, the present disclosure provides an implant comprising: a head portion at a proximal end of the implant and including external threads and a first axial throughbore; an anchor portion at a distal end of the implant and extending from the head portion; an anchor portion at the distal end of the implant and including external threads and a second axial throughbore communicating with the first axial throughbore, extending from the head portion; and a flexible constraint member extending within the first and second axial throughbore, the constraint member having a first end connected to the head portion and a second end connected to the anchor portion. At least one of the head portion and the anchor portion forms a breakaway portion configured to concentrate stress therein, such that the implant breaks due to a force acting on the implant at the breakaway portion, separating the head portion and the anchor portion. The breakaway portion includes an outer circumferential groove and an inner circumferential groove axially aligned with the outer groove, the inner circumferential groove being at least partially formed by an inner end surface portion of the head portion and an inner end surface portion of the anchor portion.

[0009] In some embodiments, the inner end surface portion of the head portion comprises an arcuate inner end surface portion of the head portion, and the inner end surface portion of the anchor portion comprises an arcuate inner end surface portion of the anchor portion, hi some embodiments, the inner end surface portion of the head portion comprises a chamfered inner end surface portion of the head portion, and the inner end surface portion of the anchor portion comprises a chamfered inner end surface portion of the anchor portion.

[0010] In some embodiments, the proximal end of the anchor portion includes a coupling cavity, and the distal end of the head portion includes a coupling protrusion corresponding to the coupling cavity, the coupling protrusion being received within the coupling cavity. In some embodiments, the bottom of the coupling cavity defines an inner end surface portion of the anchor portion, and the tip of the coupling protrusion defines an inner end surface portion of the head portion. In some embodiments, the coupling cavity and the coupling protrusion are welded together.

[0011] In some embodiments, the head portion and the anchor portion are welded together. In some embodiments, the head portion and the anchor portion are laser welded together.

[0012] In some embodiments, the head portion and the anchor portion are welded together at a weld zone positioned axially adjacent the outer groove and the inner groove, hi some embodiments, the weld zone includes a coupling projection and a coupling cavity welded together.

[0013] In some embodiments, the flexible restraining member comprises an elastic member.In some embodiments, the flexible restraining member comprises a suture loop.

[0014] In some embodiments, the implant further comprises a head post member retained within the enlarged portion of the first axial throughbore, the head post member coupled to the first end of the flexible restraining member, hi some embodiments, a resilient member is axially positioned within the enlarged portion of the first axial throughbore between the proximal end of the enlarged portion and the head post member.

[0015] In some embodiments, the implant further comprises an anchor post member positioned within the second axial throughbore and fixedly coupled to the anchor portion, the anchor post member coupled to the second end of the flexible restraining member. In some embodiments, a proximal end of the anchor post member includes at least one hook. In some embodiments, the anchor post member comprises an external groove into which the coupling portion of the anchor member deforms.

[0016] In some embodiments, the head portion includes a shaft portion having a first end and a second end, a head extending from the first end of the shaft portion, and a first release coupling portion extending from the second end of the shaft portion. In some embodiments, a portion of the shaft portion of the head portion includes external threads. In some embodiments, the head includes a non-circular drive opening at its free axial end, the non-circular drive opening forming a portion of the first axial throughbore. In some embodiments, the first release coupling portion includes a coupling protrusion having an inner surface defining an inner end surface portion of the head portion, the inner surface of the coupling protrusion forming a portion of the first axial throughbore. In some embodiments, the first release coupling portion further includes a stop surface extending radially from the outer surface of the coupling protrusion and axially positioned between the inner end surface portion of the coupling protrusion and the head. In some embodiments, the anchor portion includes a second release coupling portion at its first end including a coupling cavity having an inner bottom surface defining an inner end surface portion of the anchor portion, the inner surface of the coupling protrusion forming a portion of the first axial throughbore. In some embodiments, the coupling protrusion fits within the coupling cavity. In some embodiments, the coupling protrusion and the coupling cavity are welded together.In some embodiments, an end face of the second release coupling abuts a stop surface of the first release coupling.

[0017] In some embodiments, the anchor member further includes a shaft portion having a first end and a second end, and a crimp portion extending from the second end, and the second release coupling extends from the first end of the shaft portion. In some embodiments, a portion of the shaft portion of the anchor member includes external threads. In some embodiments, a proximal portion of the shaft portion includes a plurality of outer planar surfaces circumferentially arranged around the proximal coupling portion that form the proximal external drive mechanism. In some embodiments, the crimp portion includes a plurality of outer planar surfaces circumferentially arranged around the proximal coupling portion that form the distal external drive mechanism.

[0018] In some embodiments, the first axial throughbore of the head portion comprises a first enlarged portion positioned proximate the head portion and a second narrow portion positioned proximate the breakaway portion, and the implant further comprises a head post member positioned within the first enlarged portion of the first axial throughbore and coupled to a first end of the flexible restraint member. In some embodiments, the implant further comprises at least one resilient member positioned axially within the first enlarged portion of the first axial throughbore between the second narrow portion and the head post member. In some embodiments, the second narrow portion, the at least one resilient member, and the head post member are configured to prevent axial translation of the at least one resilient member and the head post member through the second narrow portion. In some embodiments, the at least one resilient member comprises at least one tube formed of thermoplastic urethane, polycarbonate urethane, or a combination thereof.

[0019] In some embodiments, the implant further comprises a distal post member positioned within the second axial throughbore and coupled to a second end of the flexible restraining member. In some embodiments, the distal post member is positioned proximate the distal free end of the implant and includes a hook slot extending from the end of the distal post member. In some embodiments, the distal post member has a recess in its outer surface configured to receive a deformed portion of the anchor portion to axially secure the distal post within the second axial throughbore.

[0020] In some embodiments, the flexible restraining member comprises a suture. In some embodiments, the flexible restraining member comprises a loop.

[0021] In some embodiments, the head portion, breakaway portion, and anchor member are integrated. In some embodiments, the implant is integrated. In some embodiments, the implant includes a cannula opening extending through the entire axial length of the implant.

[0022] In another aspect, the present disclosure provides a method of inserting an implant, including obtaining an implant as disclosed herein; engaging the implant with an insertion instrument; and inserting the implant into a patient so that the head portion is positioned within a first bone, the anchor portion is positioned within a second bone, and the release portion is positioned within a joint between the first and second bones.

[0023] In some embodiments, the first bone is the fibula and the second bone is the tibia. In some embodiments, the implant is inserted as a one-piece construct. In some embodiments, the implant allows movement between the first bone and the second bone after breakaway portions in the peripheral and inner circumferential grooves break away.

[0024] These and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of various aspects of the disclosure taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the detailed description, serve to explain the principles of the present disclosure. It is emphasized that, according to standard industry practice, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of discussion. The drawings are only for the purpose of illustrating preferred embodiments and are not to be construed as limiting the disclosure.

[0026] [Figure 1] FIG. 1 is a perspective side view of an exemplary dynamic fixation implant according to one aspect of the present disclosure. [Figure 2] 2 shows another perspective side view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 3] FIG. 2 shows a side view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 4] FIG. 2 shows an end view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 5] 2 shows another end view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 6] FIG. 2 shows a cross-sectional side view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 7] 2 shows a side cross-sectional view of a portion of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 8] 2 shows a cross-sectional side view of another portion of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 9] 2 shows a cross-sectional side view of another portion of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 10] FIG. 2 shows a cross-sectional side view of the implant of FIG. 1 with the tension member removed according to one embodiment of the present disclosure. [Figure 11] FIG. 2 shows an exploded perspective view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 12] 2 shows another exploded perspective view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 13] FIG. 2 shows an exploded side view of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 14]2 shows a perspective view of an exemplary anchor portion of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 15] FIG. 15 shows another perspective view of the anchor portion of FIG. 14 according to one embodiment of the present disclosure. [Figure 16] FIG. 15 shows an end view of the anchor portion of FIG. 14 according to one embodiment of the present disclosure. [Figure 17] FIG. 15 shows a side view of the anchor portion of FIG. 14 according to one embodiment of the present disclosure. [Figure 18] FIG. 15 shows a side cross-sectional view of the anchor portion of FIG. 14 according to one embodiment of the present disclosure. [Figure 19] FIG. 2 shows a perspective view of an exemplary head portion of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 20] FIG. 20 shows another perspective view of the head portion of FIG. 19 according to one embodiment of the present disclosure. [Figure 21] FIG. 20 shows an end view of the head portion of FIG. 19 according to one embodiment of the present disclosure. [Figure 22] FIG. 20 shows a side view of the head portion of FIG. 19 according to one embodiment of the present disclosure. [Figure 23] FIG. 20 shows a cross-sectional side view of the head portion of FIG. 19 according to one embodiment of the present disclosure. [Figure 24] FIG. 2 shows a perspective view of an exemplary anchor portion and head portion assembly of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 25] FIG. 25 shows a cross-sectional side view of the assembly of FIG. 24 according to one embodiment of the present disclosure. [Figure 26] FIG. 2 shows a perspective view of an exemplary tip post of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 27] FIG. 27 shows another perspective view of the tip post of FIG. 26 according to one embodiment of the present disclosure. [Figure 28] FIG. 27 shows an end view of the tip post of FIG. 26 according to one embodiment of the present disclosure. [Figure 29] FIG. 27 shows a side view of the tip post of FIG. 26 according to one embodiment of the present disclosure. [Figure 30] FIG. 2 shows a perspective view of an exemplary head post of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 31]FIG. 31 shows another perspective view of the head post of FIG. 30 according to one embodiment of the present disclosure. [Figure 32] FIG. 31 shows an end view of the head post of FIG. 30 according to one embodiment of the present disclosure. [Figure 33] FIG. 2 shows a perspective view of an exemplary tension member of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 34] 33, the tip post of FIGS. 26-29, and the head post of FIGS. 30-32 of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 35] FIG. 2 shows a perspective view of an exemplary elastic member of the implant of FIG. 1 according to one embodiment of the present disclosure. [Figure 36] 1 illustrates a side view of an alternative embodiment of an exemplary dynamic fixation implant according to an aspect of the present disclosure. [Figure 37] FIG. 37 shows a cross-sectional side view of the implant of FIG. 36 according to one embodiment of the present disclosure. [Figure 38] FIG. 37 shows a perspective view of a portion of the implant of FIG. 36 according to one embodiment of the present disclosure. [Figure 39] FIG. 37 shows an enlarged side view of a portion of the implant of FIG. 36 according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] Generally, disclosed herein are devices and systems for achieving ligament fixation. Additionally, methods of using the devices and systems for achieving ligament fixation are discussed.

[0028] In this detailed description and the claims that follow, the terms proximal, distal, anterior or plantar, posterior or dorsal, medial, lateral, superior, and inferior are defined by standard usage to refer to a particular portion or part of a bone or implant according to the patient's relative alignment or directional reference. For example, "proximal" refers to the portion of the device or implant closest to the torso, while "distal" refers to the portion of the device or implant furthest from the torso. With respect to directional terms, "anterior" refers to a direction toward the front side of the body, "posterior" refers to a direction toward the rear side of the body, "medial" means toward the midline of the body, "lateral" refers to a direction away from the midline of the body toward the side, "superior" means upward, and "inferior" refers to a direction below another object or structure. Further, with respect to the foot, the term "dorsal" refers to the top of the foot, and the term "plantar" refers to the bottom of the foot.

[0029] Similarly, location or orientation may be used herein with reference to anatomical structures or surfaces. For example, because the present implants, devices, instruments, and methods are described herein with reference to use with the ankle bone, bones of the foot, ankle, and lower leg may be used to describe the surface, location, direction, or orientation of the implants, devices, instruments, and methods. Furthermore, the implants, devices, instruments, and methods, as well as their aspects, components, features, etc., disclosed herein are described with reference to one side of the body for simplicity. However, because the human body is relatively symmetrical or mirror-imaged about a line of symmetry (the midline), it is expressly contemplated that the implants, devices, instruments, and methods, as well as their aspects, components, features, etc., described and / or illustrated herein may be changed, altered, modified, reconfigured, or otherwise modified for use with or in connection with the other side of the body for the same or similar purposes without departing from the spirit and scope of the present disclosure. For example, implants, devices, instruments, and methods, as well as their aspects, components, features, etc., described herein with respect to the right leg may be mirrored to function similarly on the left leg. Additionally, although the implants, devices, instruments and methods, and aspects, components, features, etc., disclosed and described herein are described with respect to the leg for purposes of simplicity, it should be understood that the implants, devices, instruments and methods can be used with other bones in the body having similar structures.

[0030] The implants, systems, and related methods disclosed herein are similar to those disclosed in International Patent Application No. PCT / US2018 / 057554 (filed October 25, 2018), International Patent Application No. PCT / US2018 / 055028 (filed October 9, 2018), and International Patent Application No. PCT / US2018 / 051349 (filed September 17, 2018), which are expressly incorporated herein by reference in their entireties.

[0031] Referring to the drawings, like reference numerals are used to indicate like or similar components throughout the several views, and with particular reference to FIGS. 1-13, implant 100 is shown. Implant 100 can be configured, for example, to heal syndesmotic ligaments after surgery. Implant 100 is configured to selectively constrain movement between two or more bones in all directions to allow healing of one or more ligaments extending therebetween. After the ligaments (e.g., syndesmotic ligaments) have healed, implant 100 is configured to allow physiological movement between the bones or bone segments. With respect to syndesmotic ligaments, implant 100 is also configured to recreate pressure within the lateral gutter.

[0032] The components and portions of implant 100 may be made of, for example, titanium, stainless steel, polymer, polyester, UHMWPE, thermoplastic (eg, thermoplastic urethane), bioresorbable material, or any other biocompatible material.

[0033] As shown in FIGS. 1-13, the implant 100 allows for thread-like implantation and temporary rigid fixation, and then the implant 100 transitions after insertion to provide semi-constrained motion. The temporary rigid fixation of the implant 100 provides a stabilization period for the immobilized joint during healing, after which physiological motion is permitted. The region of semi-constrained motion permitted by the implant 100 can be located in the space or gap between adjacent bones or bone segments (e.g., the fibula and tibia), reducing the risk of subsequent damage to the natural bone. As shown in FIGS. 6-9, 11-13, 33, and 24, the implant 100 can include flexible restraint and / or tension members or tethers 150 extending between the proximal and distal portions of the implant 100, which may be elastic and configured to mimic the function, location, and / or length of interosseous ligaments, for example. The surgical method for implanting the implant 100 can include forming (e.g., drilling) a hole or cavity through both bones / bone segments (e.g., the tibia and fibula) and inserting the implant 100 sized to fill the bone hole or cavity to provide a strong post-operative construct.

[0034] As shown in Figures 1-35, implant 100 includes a head portion or member 110 (or fibular member), an anchor portion or member 130 (or tibial member), a decoupling portion 160, a flexible restraint or tensioning member 150, a resilient member 150, a head post 128, and a tip post 144. Decoupling portion 160 may be positioned between head portion 110 and anchor portion 130, as shown in Figures 1-13, and allows anchor portion 130 (and head portion 110) to be secured to bone as a unitary (integral) construct when head portion 110 is twisted or rotated about the axis of implant 100. Tension member 150 can extend into / through a through-hole or cannulation (i.e., cannula opening) 120 of implant 100 that at least partially passes through head portion 110 and anchor portion 130, as shown in Figures 6-9, 11-13, and 24, and as described below. Head portion 110, anchor portion 130, flexible restraint or tension member 150, resilient member 150, head post 128, and / or tip post 144 can be made of, for example, titanium, stainless steel, a polymer, or other biocompatible material as known to those skilled in the art.

[0035] In some embodiments, the implant 100 can have an overall axial length of, for example, about 40 mm to about 70 mm. In some embodiments, the head portion 110 can have an axial length of, for example, about 10 mm to 25 mm, and the anchor portion 130 can have a length of, for example, about 15 mm to 65 mm. In one embodiment, the axial length of the head portion 110 can remain constant, while the axial length of the anchor portion 130 can be variable to accommodate various sizes of patient bones. In this manner, a system or kit according to the present disclosure can include multiple implants 100 with different axial lengths, which can include head portions 110 with the same or similar axial lengths and anchor portions 130 with different axial lengths. Alternatively, in other embodiments, the head portion 110 can be available in multiple axial lengths, for example, to accommodate various sizes of patient bones, while the axial length of the anchor portion 130 can remain constant. In this manner, a system or kit according to the present disclosure can include multiple implants 100 of different overall axial lengths, which can include anchor portions 130 of the same or similar axial lengths and head portions 110 of different axial lengths. In yet other embodiments, both the head portion 110 and the anchor portion 130 can be available in multiple axial lengths, allowing selection based on the patient's bone size. In this manner, a system or kit according to the present disclosure can include multiple implants 100 of different overall axial lengths, which can include head portions 110 with different axial lengths and / or anchor portions 130 with different axial lengths.

[0036] As shown in FIGS. 1-13 and 19-25, the head portion 110 includes a shaft portion 116 with a head or button 112 at a first proximal end and a release coupling 122 at a second distal end. The head 112 can include a tool engagement opening 114 positioned at its free axial end (of the head portion 110). The tool engagement opening 114 can have a non-circular cross-section, such as a multi-lobed opening as shown in FIGS. 2, 5, 20, and 21, although other non-circular shapes are also envisioned (e.g., a hexagonal or hexalobular drive mechanism). A tool engagement opening 114 with an irregular or non-circular cross-sectional shape can be sized and shaped to accommodate a tool that can fit therein and apply torque to the implant 100 to rotate the implant 100 about its longitudinal axis. Engagement opening 114 may include or be part of a through-hole, opening, or cannula (or cannula opening) 152 in head portion 110. Cannula opening 152 in head portion 110 may form part of or include a cannula opening or axial through-hole 120 in implant 100 (when head portion 110 is assembled to anchor portion 130).

[0037] Shaft portion 116 may include external threads and a through-hole, aperture, or cannulation 120, as shown in Figures 1-13 and 19-25. Cannula aperture 120 may extend entirely through shaft portion 116, and potentially through head portion 110, along the longitudinal axis of head portion 110, as shown in Figures 6, 01, and 21. As noted above, cannula aperture 120 may extend entirely through head 112 and may be in communication with tool engagement aperture 114 (i.e., tool engagement aperture 114 may be part of cannula aperture 120 in head portion 110).

[0038] As shown in FIGS. 6, 7, 9-13, 19, 22, and 23, the detachment coupling portion 122 may include an axially extending coupling protrusion or tip 164 at the second end of the head portion 110. In some embodiments, the coupling protrusion 164 may be cylindrical (e.g., define a cylindrical outer surface). The cannula opening 120 extends through the detachment coupling portion 122, thereby opening at its free axial end, as also shown in FIGS. 6, 7, 9-13, 19, 22, and 23. As also shown in FIGS. 6, 7, 9-13, 19, 22, and 23, the detachment coupling portion 122 may further include an outer collar or stop surface 165 at the proximal end of the coupling protrusion 164. The outer collar or stop surface 165 may extend radially outward from the outer surface of the coupling protrusion 164 and may be substantially annular and / or planar.

[0039] As shown in Figures 6, 7, 9-13, 19, 22, and 23, coupling projection 164 may include or define an inner end surface portion 166 at the free axial end of release coupling 122 (and head portion 110 as a whole) that defines the distal end of cannula opening 120. As described further below, inner end surface portion 166 can cooperate with inner end surface portion 174 of anchor portion 130 to form an inner circumferential groove 190 within cannula opening 120 of implant 100, as shown in Figures 6, 7, 9, 10, and 25. As shown in Figures 6, 7, 9-13, 19, 22, and 23, inner end surface portion 166 of coupling projection 164 may extend radially outward as it extends axially to or toward the proximal end of coupling projection 164. In some embodiments, the inner end surface portion 166 of the coupling projection 164 extends from the inner surface portion of the coupling projection 164 / shaft portion 116 to the outer surface of the coupling projection 164 .

[0040] As shown in FIGS. 6, 7, 9-13, 19, 22, and 23, in some embodiments, the inner end surface portion 166 of the coupling protrusion 164 may extend in an arcuate manner axially to or radially outward toward the proximal end of the coupling protrusion 164. As such, the inner end surface portion 166 of the coupling protrusion 164 may comprise an arcuate convex surface portion. For example, the inner end surface portion 166 may be defined by at least one radius. In some other embodiments (not shown), the inner end surface portion 166 of the coupling protrusion 164 may extend axially to or radially outward toward the proximal end of the coupling protrusion 1641 and linearly. For example, the inner end surface portion 166 may be defined by at least one flat or linear chamfered surface. In some other embodiments (not shown), the inner end surface portion 166 of the connecting projection 164 may extend radially outward and axially toward the proximal end of the connecting projection 1641, or axially, or in an arcuate shape in the axial direction, for example, the inner end surface portion 166 may be defined by at least one flat or straight chamfered surface portion and at least one arcuate surface portion defined by at least one radius.

[0041] Cannula opening 152 of head portion 110 is configured to receive and potentially axially slide or translate head post 128 of implant 100 therein, as shown in Figures 6, 7, and 10. As shown in Figures 6, 7, and 10, cannula opening 152 of head portion 110 includes a proximal enlarged portion 153 positioned proximate the first end / head 112 and a distal reduced or narrowed portion 155 positioned proximate the second end / connecting protrusion 164 of head portion 110. Enlarged portion 153 of cannula opening 152 of head portion 110 is sized and shaped to house or accommodate head post 128, allow axial movement of head post 128, and to house or accommodate at least one tension member 151 positioned axially / longitudinal between head post 128 and narrowed portion 155 of cannula opening 152. At least one elastic member 151 may include a through-hole 162, and the flexible restraining member 150 or tensioning member 150 may extend through the through-hole 162 of the at least one elastic member 151 (e.g., the at least one elastic member 151 may extend around the restraining and / or tensioning member 150), as shown in FIGS. 6, 7, 10, and 35. For example, the at least one elastic member 151 may extend circumferentially around the restraining and / or tensioning member 150. The narrow portion 155 of the cannula opening 152 is sized and shaped to allow the restraint and / or tensioning member 150 to pass axially therethrough, but to prevent the head post 128 and the at least one elastic member 151 from passing or translating (axially) therethrough.

[0042] At least one resilient member 151 is configured (e.g., sized and shaped) such that narrow portion 155 of cannula opening 152 and head post 128 are trapped or housed between head post 128 and the narrow portion of cannula opening 152, as shown in Figures 6, 7, 10, and 35. In this manner, when restraining and / or tensioning member 150 is tensioned (as described below), at least one resilient member 151 is resiliently compressed between the end of enlarged portion 153 of cannula opening 152 in head portion 110 and head post 128. This allows at least one resilient member 151 to apply a compressive force that pulls anchor portion 130 and head portion 110 together after release portion 160 of implant 100 fractures / breaks, and / or allows for a limited degree of relative axial translation or movement between anchor portion 130 and head portion 110.

[0043] In some embodiments, the at least one elastic member 151 can be composed of one or more elastically deformable members or materials. For example, the at least one elastic member 151 can be one or more springs (e.g., disks or coil springs) or elastically compressible disks or tubes, or combinations thereof. For example, the at least one elastic member 151 can include an elastically compressible disk (e.g., a disk made of an elastomer, polymer, polyurethane, or polyethylene), a tube (e.g., polyurethane tubing), or a coil spring. In some embodiments, the at least one elastic member 151 includes at least one urethane tube or similar member, such as at least one polycarbonate urethane (PCU) tube or similar member, or at least one thermoplastic polyurethane (TPU) tube or similar member. In some such embodiments, the at least one elastic member 151 can include a 75A durometer, an 85A durometer, or a 95A durometer urethane tube or similar member.

[0044] In some embodiments, the at least one elastic member 151 can be made of, for example, extruded thermoplastic urethane (TPU) with a durometer of, for example, 75-95 Shore A. In some embodiments, the at least one elastic member 151 can have an outer width or diameter of, for example, about 1.5 mm. The inner width or inner diameter of the through-hole 162 of the at least one elastic member 151 can vary based at least in part on the desired stiffness of the elastic member 151. In some embodiments, the at least one elastic member 151 can have a length of, for example, about 3 mm.

[0045] The at least one elastic member 151 is configured to elastically deform and tension the restraining and / or tensioning member 150 such that it (through elastic deformation of the at least one elastic member 151) applies a compressive force that pulls the anchor portion 130 and the head portion 110 together (before and / or after the detachment portion 160 of the implant 100 breaks / fails) and / or allows for limiting the degree of relative axial translation or movement between the anchor portion 130 and the head portion 110 (after the detachment portion 160 of the implant 100 breaks / fails). The at least one elastic member 151 can provide an assembly tension that holds the anchor portion 130 and the head portion 110 together before welding them (as described below), and an in situ tension after implantation and failure of the detachment portion 160 of the implant 100 to withstand anatomical forces, such as ligamentous syndesmosis forces. For example, when implant 100 is implanted into the fibula and tibia and breakaway portion 160 of implant 100 is at least partially positioned within the transverse trough, the in situ tension provided at least in part by at least one elastic member 151 allows or provides recoverable diastatic movement of the fibula relative to the tibia, e.g., moves to relieve, absorb, and / or dissipate pressure spikes at the transverse trough. In some embodiments, at least one elastic member 151 is elastically deformable, and the assembly tension maintains the components of implant 100 mated together, and at least one elastic member 151 is elastically deformable and provides the in situ tension in response to the recoverable diastatic movement and pressure spikes.

[0046] Anchor portion 130 can include a shaft portion 132 including a release coupling portion 138 at a first proximal end and a crimp portion 133 at a second distal end, as shown in Figures 1-18, 24, and 25. Shaft portion 132 can be threaded along a portion of the shaft, such as the portion extending from at or near release coupling portion 138 to crimp portion 133. The distal end of the threads of anchor portion 130 adjacent the second end of the anchor portion can include at least one cutting element, e.g., at least one flute (e.g., cutting groove). Crimp portion 133 can also be a non-threaded portion of anchor portion 130 extending from the threaded portion to the distal free end of anchor portion 130.

[0047] Anchor portion 130 also includes a through-hole, opening, or cannula (or cannula opening) 134. Cannula opening 134 of anchor portion 130 may form or comprise a portion of cannula opening or axial through-hole 120 of implant 100 (when anchor portion 130 is assembled with head portion 110). Cannula opening 134 may extend through the entire length of anchor portion 130 along the longitudinal axis, as shown in FIGS. 6, 9, 10, 18, and 25. As mentioned above, cannula opening 120 of implant 100 may pass through head 112 and communicate with tool engagement opening 114 (i.e., tool engagement opening 114 may be a portion of cannula opening 120 of head portion 110).

[0048] As shown in Figures 6, 7, 9, 10, 12, 15, 18, and 25, the proximal end of detachment coupling portion 138 may include a coupling cavity 172 configured to mate (e.g., an interference fit) with coupling protrusion 164 of head portion 110 such that coupling protrusion 164 of head portion 110 is received within coupling cavity 172. This allows coupling cavity 172 to have a configuration (e.g., size and shape) that substantially corresponds to that of coupling protrusion 164 of head portion 110. Coupling cavity 172 may form or comprise an enlarged portion of cannula opening 134 of anchor portion 130 proximal to a narrower portion of cannula opening 134 of anchor portion 130, as shown in Figures 6, 9, 10, 18, and 25. Cannula opening 134 extends through release coupling portion 164 and is open at its free axial end, as shown in FIGS.

[0049] 6 , 9 , 10 , 18 , and 25 , a distal bottom, end, or surface 174 of coupling cavity 172 of release coupling portion 138 of anchor portion 130 defines or comprises an inner end surface portion of anchor portion 130. As described above, inner end surface portion 174 of coupling cavity 172 of anchor portion 130 cooperates with inner end surface portion 166 of release coupling portion 122 of head portion 110 to form an inner circumferential groove 190 within cannula opening 120 of implant 100. Inner end surface portion 174 of coupling cavity 172 may extend radially outward from an outer inner surface portion of the enlarged portion of coupling cavity 172 to an outer inner surface portion of the narrowed portion of coupling cavity 172, and may be substantially annular.

[0050] 6, 9, 10, 18, and 25, inner end surface portion 174 of linking cavity 172 of anchor portion 130 may extend radially inward (from the enlarged portion to the narrowed portion of linking cavity 172) as it extends axially or toward crimp portion 133. In some embodiments, inner end surface portion 174 of linking cavity 172 extends from the distal end of the enlarged portion of linking cavity 172 to the proximal end of the narrowed portion of linking cavity 172, as shown in FIGS. 6, 9, 10, 18, and 25.

[0051] As shown in FIGS. 6 , 9 , 10 , 18 , and 25 , in some embodiments, the inner end surface portion 174 of the connecting cavity 172 may extend radially outward, axially, or in an arcuate manner toward the crimped portion 133 (from the enlarged portion to the narrowed portion of the connecting cavity 172). This allows the inner end surface portion 174 of the connecting cavity 172 to have an arcuate convex surface portion. For example, the inner end surface portion 174 of the connecting cavity 172 may be defined by at least one radius. In other embodiments (not shown), the inner end surface portion 174 of the connecting cavity 172 may extend radially outward, axially, or in a linear manner toward the crimped portion 133 (from the enlarged portion to the narrowed portion of the connecting cavity 172). For example, the inner end surface portion 174 of the connecting cavity 172 may be defined by at least one flat or linear chamfered surface. In some other embodiments (not shown), the inner end surface portion 174 of the connecting cavity 172 may extend radially outward, axially, or toward the crimped portion 133 in a linear and arcuate manner (from the enlarged portion to the narrowed portion of the connecting cavity 172). For example, the inner end surface portion of the connecting cavity 172 may be defined by at least one flat or linear chamfered surface portion and at least one arcuate surface portion defined by at least one radius.

[0052] As shown in Figures 6, 7, 9, 10 and 25, an inner end surface portion 174 of the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130 cooperates with an inner end surface portion 166 of the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 to form an inner circumferential groove 190 within the cannula opening 120 of the release portion 160 of the implant 100. The inner circumferential groove 190 within the cannula opening 120 of the release portion 160 of the implant 100 may comprise, for example, a notch, groove, necking, or recess in the interior surface of the implant 100 that defines the cannula opening 120. The inner end surface portions 166, 174 may be arcuate / curved and / or flat / planar, and the inner circumferential groove 190 of the release portion 160 may have, for example, a curved / arcuate / rounded and / or flat / planar surface. The bottom or deepest portion of the inner circumferential groove 190 of the breakaway portion 160 may be arcuate or linear / straight.

[0053] 6, 7, 9, 10, 13-15, 17, 18, 25, and 26, the outer surface of the proximal end of the detachment coupling portion 138 (i.e., the outer surface of the proximal end extending around and / or forming the coupling cavity 172) includes a circumferential groove 192 that is axially aligned within (i.e., extends around) the inner circumferential groove 190 at the cannula opening 120 of the detachment portion 160 of the implant 100. The circumferential groove 192 of the detachment portion 160 of the implant 100 may comprise, for example, a notch, a groove, a necking, or a recess in the outer surface of the breakaway portion 160 of the implant 100. The circumferential groove 192 may have, for example, a curved / arcuate / rounded shape and / or a flat / planar surface. The bottom or deepest portion of the circumferential groove 192 of the breakaway portion 160 may be arcuate or linear / straight.

[0054] 6, 7, 9, 10 and 25, the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 may be initially freely assembled / positioned within the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130. In some embodiments, the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 and the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130 mate to comprise an interference fit.

[0055] A proximal end surface of coupling cavity 172 of release coupling portion 138 of anchor portion 130 can abut or seat against outer collar or stop surface 165 of release coupling portion 122 of head portion 110, as shown in FIG. 7. In some other embodiments (not shown), the proximal end surface of coupling cavity 172 of release coupling portion 138 of anchor portion 130 can be axially spaced from outer collar or stop surface 165 of release coupling portion 122 of head portion 110. In some embodiments, an inner end surface portion 166 of coupling protrusion 164 of release coupling portion 122 of head portion 110 can be axially spaced from an inner end surface portion 174 of coupling cavity 172 of release coupling portion 138 of anchor portion 130, as shown in FIG. 7. In some other embodiments (not shown), the inner end surface portion 166 of the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 may abut the inner end surface portion 174 of the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130.

[0056] As shown in FIGS. 6, 7, 9, and 10, restraining and / or tensioning member 150 may be an elongated structure or member extending from or adjacent to (and secured to) crimping portion 133 of anchor portion 130 and at least adjacent to (and secured to) shaft portion 116 and / or head 112 of head portion 110. In an exemplary embodiment of implant 100, restraining and / or tensioning member 150 comprises a suture, specifically a continuous suture loop. In one exemplary embodiment, the suture may comprise a size #0 suture. Restraining and / or tensioning member 150 may have other configurations or structures. Restraining and / or tensioning member 150 may be, for example, a twisted cerclage cable or similar construct. Restraining and / or tensioning member 150 can be made of, for example, titanium, stainless steel, polymer, polyester, polypropylene, or UHMWPE suture, co-braid thereof, or similar materials as known to those skilled in the art. Restraining and / or tensioning member 150 can also be, for example, a suture (e.g., a braided suture), such as a single cross-sectional strand of suture or multiple loops of suture. For example, restraining and / or tensioning member 150 can be a UHMWPE and polypropylene co-braided suture. Restraining and / or tensioning member 150 may or may not be elastically stretchable or deformable axially / longitudinally.

[0057] As shown in Figures 6, 7, 9, 10, 33, and 34, restraining and / or tensioning member 150 may comprise a loop having first and second ends 157, 159. As described below, first and second open ends 157, 159 of the opening or loop of restraining and / or tensioning member 150 are configured to accommodate or receive a pin extending through the loop to first and second ends 157, 159, respectively, so that restraining and / or tensioning member 150 can be pulled into tension (or apply a tension that functions to pull head portion 110 and anchor portion 130 together). First end 157 of restraining and / or tensioning member 150 can be coupled to head portion 110 within its cannula opening 152 via head post 128, as shown in Figures 6, 7, and 25. The head post 128 can be received or positioned within an enlarged portion 153 of the cannula opening 152 in the head portion 110 .

[0058] 30-32 and 34, head post 128 includes an axially / longitudinally extending throughbore and a cannula opening or passageway 129 extending therethrough, the latter configured to allow passage of first end 157 of a loop of restraining and / or tensioning member 150. Head post 128 also includes at least one laterally / radially extending pin opening or hole 118 extending from the exterior of head post 128 to the exterior surface of head post 128 (thereby forming cannula opening 152). First end 157 of tensioning member 150 can be inserted or passed through cannula opening 129 in head post 128 such that the opening of the loop of tensioning member 150 is aligned with pin opening 918. The openings in tensioning member 150 are aligned with pin openings 118, and head pin 119 can be press-fit into pin opening 118 and into / through the opening to secure first end 157 of restraining and / or tensioning member 150 to head post 128, as shown in Figures 6, 7, 30-32, and 34. In some embodiments, head pin 119 can initially be partially positioned or pre-assembled within a portion of pin opening 118 prior to passing restraining and / or tensioning member 150 through cannula opening 129.

[0059] Second end 159 of restraining and / or tensioning member 150 may be coupled to anchor portion 130 within its cannula opening 134 via distal post 144, as shown in FIGS. 6, 8, 9, and 34. Distal post 144 may be received or positioned within cannula opening 134 of anchor portion 130 (e.g., cannula opening 134 of crimped portion 133 and / or threaded shaft portion 132). In particular, cannula opening 134 of anchor portion 130 (e.g., cannula opening 134 of crimped portion 133 and / or threaded shaft portion 132) is configured to allow distal post 144 to slide or translate axially therethrough in a neutral, natural, or uncrimped or uncrimped state, as shown in FIGS. 8 and 9. As described further below, the crimped portion 133 of the anchor portion 130 may be deformed or crimped inwardly so that the cannula opening 134 is constricted or partially collapsed to secure or capture the distal post 144 at a specific or selected axial position or location within the cannula opening 134 along the crimped portion 133 of the anchor portion 130 (not shown).

[0060] As shown in Figures 6, 8, 9, and 34, distal post 144 includes an axially / longitudinally extending throughbore and a cannula opening or passageway 139 configured to allow second end 159 of restraining and / or tensioning member 150 to pass therethrough. Distal post 144 also includes at least one laterally / radially extending pin opening or hole 136 positioned proximate the second end of distal post 144. Pin opening 136 extends from the exterior of distal post 144 to cannula opening 139. A first end 157 of tensioning member 910 can be inserted or passed through cannula opening 139 in distal post 144 so that it is aligned with pin opening 136. The opening in the loop of restraining and / or tensioning member 150 is aligned with pin opening 136, and distal pin 135 can be press-fit into pin opening 136 and into the opening in restraining and / or tensioning member 150, as shown in Figures 6, 8, 9 and 34, to secure second end 159 of restraining and / or tensioning member 150 to distal post 144. In some embodiments, distal pin 135 can be initially partially positioned or pre-assembled within a portion of pin opening 136 before passing restraining and / or tensioning member 150 through cannula opening 139.

[0061] Distal post 144 also includes a hook slot 137 (e.g., a J-, L-, or T-shaped slot) extending from its second end, as shown in FIGS. 6, 8, 9, 26-29, and 34. Hook slot 137 can define a slot or passageway that is open to the second end of distal post 144. Hook slot 137 is configured to allow a member (e.g., a suture, a tool, or other member or device) (not shown) to extend therethrough to engage with and apply axial tension to distal post 144 (as indicated by the difference in axial position of distal post 144 in FIGS. 8 and 9). When distal post 144 is positioned within cannula opening 134 of anchor portion 130, the member (not shown) can extend into cannula opening 134 and pass through / engage hook slot 137. Tension can be applied to the distal post 144 through the hook slot 137, and the member therethrough / through can act in a direction extending from the head portion 112 to the anchor portion 130, translating the distal post 144 into the cannula opening 134 in the crimping portion 133 of the anchor portion 130.

[0062] As shown in Figures 6, 8, 9, 26-29, and 34, distal post 144 includes a crimping recess or groove 145 extending into the outer surface of distal post 144. Crimping recess 145 may extend circumferentially around distal post 144. Crimping recess 145 may be positioned between hook slot 137 and pin opening 136. When distal post 144 is positioned within cannula opening 134 of anchor member 912, crimping recess 145 forms a space or gap between crimping recess 145 and the inner surface of anchor member 912 that defines cannula opening 134, as shown in Figures 8-10. Thus, as described above, crimp portion 133 of anchor portion 130 can be crimped (i.e., deformed inward) so that the side walls of crimp portion 133 extend into cannula opening 134 and crimp recess 145 (i.e., cannula opening 134 narrows or partially collapses into crimp recess 145), securing or capturing distal post 144 within a particular or selected axial / longitudinal position or location within cannula opening 134 along anchor portion 130.

[0063] The exterior or outer surface of at least a portion of the crimped portion 133 of the anchor portion 130 may have an irregular or non-circular cross-section as an intermediate removal mechanism 198 for intermediate removal of the anchor portion 130 after fracture of the release portion 160 of the implant 100 by rotation of the anchor portion 130. For example, as shown in FIGS. 1-18 , 24 , and 25 , the exterior surface of at least a portion of the crimped portion 133 of the anchor portion 130 may define a removal member positioned around the anchor portion 130 that is engageable from an inner surface and utilized to rotate the anchor portion 130 to remove the anchor portion 130 from the bone. In some embodiments, the removal member may include an outer flat surface disposed circumferentially about the axis of the exterior surface of at least a portion of the crimped portion 133 of the anchor portion 130. For example, at least a portion of the exterior surface of the crimped portion 133 of the anchor portion 130 may include an external hexagonal portion, shape, or drive mechanism 198, as shown in FIGS. 1-18 , 24 , and 25 .

[0064] As shown in FIGS. 1-18 , 24 , and 25 , the exterior or outer surface of at least a portion of the anchor portion 130 may have an irregular or non-circular cross-section to serve as a lateral removal mechanism 196 for lateral removal of the anchor portion 130 after fracture of the release portion 160 of the implant 100 by rotation of the anchor portion 130. For example, as shown in FIGS. 1-18 , 24 , and 25 , the lateral removal mechanism 196 (i.e., the exterior surface of at least a portion of the anchor portion 130 proximate (but distal to) the release coupling portion 138) can define a removal member positioned around the periphery of the anchor portion 130 that is laterally engageable and can be utilized to rotate the anchor portion 130 to remove it from the bone. In some embodiments, the removal member of the lateral removal mechanism 196 may comprise an outer flat surface disposed circumferentially about the axis of the exterior surface of at least a portion of the anchor portion 130 proximate (but distal to) the release coupling portion 138. For example, at least a portion of the exterior surface of anchor portion 130 proximate (but distal to) release coupling portion 138 may include an exterior hexagonal portion, shape, or drive mechanism 196, as shown in Figures 1-18, 24, and 25.

[0065] As shown in Figures 3, 6, 17, and 18, in some embodiments, anchor portion 130 (e.g., its release coupling portion 138) may include a minor diameter extending axially through outer groove 102 that is larger than (or equal to) the minor diameter of head portion 110. In some other embodiments, anchor portion 130 (e.g., its release coupling portion 138) may include a minor diameter that extends only axially relative to (i.e., does not pass axially through) outer groove 102 that is larger than (or equal to) the minor diameter of head portion 110. Anchor portion 130 (e.g., its release coupling portion 138) may include a minor diameter that is larger than that of head portion 110 only relative to outer groove 102. In this manner, outer groove 102 may be formed in a portion of anchor portion 130 (e.g., in its release coupling portion 138) that includes a minor diameter that is smaller than the minor diameter of head portion 110.

[0066] In some embodiments, the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 can be fixedly coupled within the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130. For example, the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 and the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130 can be welded (e.g., laser welded) together. In some such embodiments, the weld can completely penetrate the release coupling portion 122 and the release coupling portion 138 of the head portion 110. For example, the inner surface (e.g., part or all of) of the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130 can be welded (e.g., integral) to the outer surface (e.g., part or all of) of the coupling protrusion 164 of the release coupling portion 122 of the head portion 110. Similarly, the proximal end face (e.g., part or all of) of the connection cavity 172 of the release connection portion 138 of the anchor portion 130 may be welded to the outer collar or stop surface 165 (e.g., part or all of) of the release connection portion 122 of the head portion 110.

[0067] This allows the breakaway coupling portion 122 of the head portion 110 and the breakaway coupling portion 138 of the anchor portion 130 to be welded together at a weld zone positioned axially adjacent to the inner and outer grooves 190, 192. Specifically, the weld zone includes a portion of the coupling protrusion 164 of the breakaway coupling portion 122 of the head portion 110 that is axially spaced from (e.g., axially adjacent to) the inner end surface portion 166 and a portion of the coupling protrusion 164 of the breakaway coupling portion 122 of the head portion 110 that is axially spaced from (e.g., axially adjacent to) the inner end surface portion 174. The breakaway portion 120 and weld zone of the implant 100 may be configured to withstand the torque required to implant the implant 100 into a bone / bone segment (i.e., a target anatomical structure) at the weld joint and breakaway portion 120 (at the internal and external grooves 190, 192), and the implant 100 may be configured to fail, fracture, or break due to in situ forces applied to the implant 100 at the internal and external grooves 190, 192, but not at the weld zone / bond joint (e.g., typical physiological forces experienced at the joint of a bone / bone segment due to patient weight bearing).

[0068] Implant 100 may thereby be configured to break (due to an in situ force) at the location of internal groove 190 formed through inner end surface portion 166 of head portion 110 and inner end surface portion 174 of anchor portion 130. The arcuate and / or chamfered configuration / nature of inner end surface portion 166 of head portion 110 and inner end surface portion 174 of anchor portion 130 provides relatively smooth, dull, and / or protective inner end surfaces of the broken / separated head portion 110 and anchor portion 130, preventing restraint and / or tension member 150 from being abraded, cut, worn, frayed, or otherwise deteriorated by the end surface surfaces of the broken / separated head portion 110 and anchor portion 130. The internal groove 190 thus formed by the arcuate and / or chamfered inner end surface portion 166 and inner end surface portion 174 prevents the formation of sharp and / or jagged internal edges on the implant 100 that may contact the restraining and / or tensioning member 150 and thereby abrade, cut, wear, fray or deteriorate the restraining and / or tensioning member 150.

[0069] The inner circumferential groove 190 and the outer circumferential groove 192 of the breakaway portion 160 can cooperate to form the portion of the implant 100 with the thinnest wall portion or radial thickness from the cannula opening 120 to its outer surface. The inner circumferential groove 190 and the outer circumferential groove 192 of the breakaway portion 160 can be configured to concentrate stresses such that a force acting on the implant 100 to separate the head portion 110 and the anchor portion 130 will cause the implant 100 to break / separate at the breakaway portion 160 (at the location of, e.g., between, the circumferential groove 190 and the outer circumferential groove 192). Note that if the breakaway portion 160 breaks / separates, the proximal end of the breakaway coupling portion 138 will remain coupled (e.g., welded) to the head portion 110.

[0070] The implant 100 may have a breakaway mechanism ratio, for example, between 64% and 89%, or between 75% and 82%, between the wall thickness or radial thickness of the implant 100 at the internal and external grooves 190, 192 compared to that of adjacent or proximal portions of the head portion 110 and / or anchor portion 130. As described above, the implant 100 can be configured such that stresses applied to the implant 100 in situ are concentrated in the breakaway portion 120 (e.g., its internal and external circumferential grooves 190, 192). In some embodiments, the breakaway portion 120 can be configured to fail (i.e., break) due to initial application of typical physiological forces experienced at a bone / bone segment articulation due to initial patient weight bearing. In some embodiments, the breakaway portion 120 can be configured to fail (i.e., break) in fatigue due to these stresses.

[0071] This allows implant 100 to provide a first period of substantially rigid fixation of the bone / bone segments, followed by a second phase of semi-constrained and / or dynamic movement between the bone / bone segments (provided by constraining and / or tensioning member 150) after failure of release portion 120. For example, implant 100 can be inserted into the tibia and fibula after syndesmosis reduction to temporarily fixate the tibia and fibula, but allow for semi-constrained and / or dynamic movement thereafter. In some such embodiments, implant 100 can be inserted into the tibia and fibula following repair of an ankle fracture, such as a fibula fracture.

[0072] This allows implant 100 to initially fully support the bone / bone segment, such as for a period of time sufficient for one or more syndesmotic ligaments to heal after surgery. The implant can also selectively constrain motion in all directions, for example, to allow one or more ligaments to heal. For example, implant 100 allows physiological motion during the period of full or rigid support to allow one or more syndesmotic ligaments to heal.

[0073] The implant 100 also allows for thread-like implantation and temporary rigid fixation, after which, after insertion, the implant 100 is designed to fail (e.g., fracture and / or degrade) at the detachment portion 120 after one or more load cycles (e.g., a number of load cycles that can vary depending on the load). The at least one load cycle may be multiple non-weight-bearing and / or weight-bearing load cycles or a single non-weight-bearing and / or weight-bearing load cycle. In some embodiments, the implant 100 can be designed to fail (i.e., break or fracture) in fatigue at the detachment portion. In some embodiments, the implant 100 can be designed to focus forces applied to the implant 100 (e.g., implantation / in situ) at the detachment portion 120, as described above, to cause failure (e.g., fatigue fracture) at the detachment portion 120. The temporary rigid fixation of the implant 100 provides a fixed union time to stabilize through-healing and allow physiological movement after detachment (e.g., fracture) of the detachment portion 120. The breakaway location can be located in a space or gap between bones / bone segments (e.g., between the fibula and tibia), reducing the risk of subsequent damage to the natural bone. Thus, forces and / or stresses applied to the implant 100 after implantation can be concentrated at the breakaway portion 120, which can be configured to fail (e.g., fracture) due to loading. In some embodiments, the configuration of the internal and external grooves 190, 192 can be optimized to provide or sustain sufficient torque to allow the implant 100 to be implanted through its rotation, while providing bending performance that will fail when the implant is loaded in situ (e.g., at an angle relative to the axis of the implant and / or the bone / bone segment).

[0074] Head portion 110 and / or anchor portion 130 can remain in the bone / bone segment (e.g., in the patient's fibula and tibia) after failure of breakaway portion 120. However, if hardware removal is necessary / desired, head portion 110 can be removed from the individual bone / bone segment after breakaway portion 102 breaks, for example, via tool engagement opening 114. Furthermore, anchor portion 130 may be removed from the individual bone / bone segment as needed / desired. Anchor portion 130 can be removed from the individual bone / bone segment, for example, medially using distal drive mechanism 198 or laterally using lateral removal member 196.

[0075] Implant 100 can be assembled by seating / positioning coupling protrusion 164 of release coupling portion 122 of head portion 110 within coupling cavity 172 of release coupling portion 138 of anchor portion 130, as described above (i.e., anchor portion 130 and head portion 110 are dynamically linked by restraining and / or tensioning member 150, at least one elastic member 151, and release portion 120). Also as described above, release coupling portion 122 of head portion 110 and release coupling portion 138 of anchor portion 130 may be welded (e.g., laser welded) together.

[0076] Assembling the implant 100 also involves positioning the second end 159 of the restraining and / or tensioning member 150 within the cannula opening 139 of the distal post 144, inserting the distal pin 135 through the pin opening 136 of the distal post 144, and passing the distal pin 135 through the second end opening 159 to couple the restraining and / or tensioning member 150 and the distal post 144 (capturing the restraining and / or tensioning member 150 to the distal post 144), as shown in FIG.

[0077] Pre-assembled restraining and / or tensioning member 150 and tip post 144 may be assembled with anchor portion 130, head portion 110, at least one resilient member 151, and head post 128. For example, first end 157 of restraining and / or tensioning member 150 can be inserted into cannula opening 134 of anchor portion 130 through an opening in the end of crimping portion 133, into cannula opening 152 of head portion 110, into through-hole 162 of at least one resilient member 151 (if provided), and into cannula opening 152 of head post 128. Restraining and / or tensioning member 150 can be positioned within the cannula opening of implant 100, and tip post 144 can also be positioned or translated into cannula opening 134 of anchor portion 130.

[0078] First end 157 of restraint and / or tension member 150 is located within cannula opening 152 of head post 128, and as shown in FIG. 7 , head pin 119 can be pushed or translated through pin opening 118 in head post 128 so that head pin 119 extends through the opening in first end 157 and couples restraint and / or tension member 150 and head post 128 (i.e., captures restraint and / or tension member 150 within head post 128), thereby allowing at least one resilient member 151 to seat within enlarged portion 153 of cannula opening 152 in head portion 112.

[0079] The restraint and / or tensioning member 150 and head post 128 are coupled, and the restraint and / or tensioning member 150 can be tensioned through the hook slot 137 in the tip post 144 to axially seat, engage, or assemble the components of the implant 100 and apply tension to the assembly. For example, a member or tool (e.g., a suture) (not shown) can be inserted into the cannula opening 134 of the anchor portion 130 and can engage with the hook slot 137 in the tip post 144. The tip post 144 and the restraint and / or tensioning member 150 can be initially positioned within the cannula opening 134 distal to the free end or tip of the anchor portion 130 (formed by the crimp portion 133). A member or tool can be positioned within cannula opening 134 adjacent the free or tip end of anchor portion 130 to apply tension to "pull" tip post 144 axially / longitudinal through cannula opening 134 of anchor portion 130 and through hook slot 137. This allows the restraining and / or tensioning member 150 to translate axially / longitudinal through the cannula opening 152 of the head portion 112, thereby seating the head post 128 within the enlarged portion 153 of the cannula opening 152 of the head portion 110 and acting on the at least one resilient member 151 to capture the at least one resilient member 151 between the narrowed portion 155 of the cannula opening 152 and the head post 128, as shown in FIG. 8 . Axial / longitudinal translation of the restraining and / or tensioning member 150 through the cannula opening 134 of the anchor portion 130 causes the head portion 110 to act against the at least one resilient member 151 to fully seat the coupling protrusion 164 of the release coupling portion 122 of the head portion 110 within the coupling cavity 172 of the release coupling portion 138 of the anchor portion 130 (if not already fully seated therein).

[0080] Further axial / longitudinal translation of distal post 144 and second end 159 of restraint and / or tensioning member 150 (by "pulling" or tensioning through hook slot 137) through cannula opening 134 in anchor portion 130 toward the free or distal end of anchor portion 130 causes head post 128 to compress at least one resilient member 151 (between head post 128 and the end of enlarged portion 153 of cannula opening 152 in head portion 110), elastically deforming at least one resilient member 151. This allows at least one resilient member 151 to apply an assembly tension to anchor portion 130 and head portion 110 via restraint and / or tensioning member 150, which acts to pull (or push) anchor portion 130 and head portion 110 together. At least one resilient member 151 can be partially elastically compressed or deformed such that in situ forces can be dissipated or absorbed by further deformation thereof. To fix or maintain the assembly force, the position of the distal post 144 adjacent the free end or tip of the anchor portion 130 within the cannula opening 134 can be fixed or maintained by crimping or inwardly deforming the crimped portion 133 of the anchor portion 130 into the crimping recess 145 of the distal post 144 (not shown).

[0081] 36-39, an alternative embodiment of implant 200 is shown. In some aspects, implant 200 can include one or more components or features of implant 100, as previously described and illustrated. Implant 200 may include additional and / or alternative features to those illustrated and described with reference to implant 100. Similar to implant 100, implant 200 can be configured to heal syndesmotic ligaments after surgery, where implant 200 is configured to selectively constrain omnidirectional movement between two or more bones to heal one or more ligaments extending therebetween. Additionally, implant 200 can be configured to allow physiological movement between the bones or bone segments after the one or more ligaments have healed. With reference to syndesmotic ligaments, implant 200 can also be configured to create, recreate, and / or relieve pressure within the ankle lateral canal.

[0082] Implant 200 is shown in FIG. 36 to include head portion 110 and anchor portion 130, as previously illustrated with reference to implant 100. Head portion 110 and anchor portion 130 may include all of the components as previously illustrated and described with reference to system 100, or may have one or more of the components illustrated and described subsequently in place of the components of implant 100. Head portion 110 is shown to include a detachment coupling portion 222 located at a first proximal end thereof. Detachment coupling portion 222 is shown to have an increased length (e.g., relative to detachment coupling portion 122) along the longitudinal axis of implant 100 (e.g., an axis through the implant, such as being circumferentially centered within cannula opening 120).

[0083] 37 , detachment connection portion 222 is illustrated as extending into anchor portion 130 of implant 200. In some embodiments, detachment connection portion 222 may extend further into anchor portion 130 than detachment connection portion 122 of implant 100. Additionally, detachment connection portion 222 may have a smaller diameter than detachment connection portion 122 to facilitate implantation and / or removal (e.g., removal after implant 200 fails, in the same or similar manner as shown and described with reference to implant 100). Additionally, the smaller diameter of detachment connection portion 222 may facilitate removal of head portion 110 if head portion 110 and / or implant 200 are removed from the patient (e.g., in the event of infection).

[0084] Anchor portion 130 of implant 200 is shown to include, as a first proximal end thereof, a release coupling portion 238, which collectively with release coupling portion 222 forms release portion 260 (see FIG. 37). As shown in FIGS. 36-38, release coupling portion 238 has a length along the longitudinal axis of implant 200 (e.g., an axis through the implant, e.g., circumferentially centered within cannula opening 120) that is greater than release coupling portion 138 of implant 100. The length of release coupling portion 238 may have a lateral dimension (e.g., cross-section) that is greater than at least a portion of release coupling portion 222 (e.g., protrusion 223, as shown in FIG. 37), allowing at least a portion of release coupling portion 222 to be received within at least a portion of release coupling portion 238 and facilitating complementary movement of these components. Disengagement coupling portion 238 includes an inner end surface portion 174 that may have the same and / or similar geometry as that shown and described with reference to implant 100. Similarly, inner end surface portion 166 may be disposed adjacent to and / or abut inner end surface portion 174 when implant 200 is assembled. In some embodiments, inner end surface portion 166 and inner end surface portion 174 may be positioned such that at least a portion of release coupling portion 222 and at least the outer diameter of release coupling portion 238 abut one another.

[0085] The anchor portion 130 of the implant 200 is further shown to include a circumferential groove 292 disposed in the outer surface of the release coupling portion 2384. In some embodiments, the circumferential groove 292 may have the same and / or similar geometry and / or dimensions as the circumferential groove 192. The circumferential groove 292 has a surface (extending circumferentially around the release coupling portion 238) and, therefore, has a corresponding geometry based on the size and / or dimensions (e.g., diameter, etc.) of the release coupling portion 238. For example, in some embodiments, the release coupling portion 238 (and, therefore, the release coupling portion 222) may have a larger or smaller diameter across one or more portions relative to the release coupling portion 138 (or, in the case of the release coupling portion 222, relative to the release coupling portion 122). Similar to the circumferential groove 192, the circumferential groove 292 may include a notch, groove, necking, or recess in the outer surface of the release coupling portion 238 and may further have a curved / arcuated / rounded shape and / or a flat / planar surface. Additionally, the circumferential groove 292 may be positioned relative to the internal groove 190 as previously shown and described with reference to the circumferential groove 192 .

[0086] Implant 200 is also illustrated as including a tip post 244, as shown in FIGS. 37 and 39 . Tip post 244 may be configured to have one or more geometries and / or dimensions that are the same as or similar to tip post 144, as shown and described with reference to implant 100. For example, tip post 244 may be configured to interfere with tension member 150 within anchor portion 130 in the same and / or similar manner as tip post 144. Tip post 244 is illustrated as including a crimping recess 245 disposed on an outer surface of tip post 244 and extending circumferentially around a portion of the outer surface of tip post 244. In some embodiments, crimping recess 245 may be located on tip post 244 in the same and / or similar position as tip post 144. In some embodiments, at least a portion of crimping recess 245 may be positioned at a smaller angle relative to the horizontal than crimping recess 145. The crimping recess 245 is shown to include a distal portion 247 and a proximal portion 249, both of which extend circumferentially around at least a portion of the outer surface of the tip post 244 and are disposed within the crimping recess 2452. At least a portion of the distal portion 247 includes a vertical segment (e.g., substantially perpendicular to the longitudinal axis of the implant 200 and / or tip post 244) configured to increase retention of the crimping portion 233 (e.g., against a force applied generally along the longitudinal axis of the implant 200) after crimping (e.g., once at least a portion of the crimping portion 233 is crimped and positioned within at least a portion of the crimping recess 245). The distal portion 247 is further shown to include at least a partial radius that is disposed radially inward from the vertical segment (e.g., closer to the longitudinal axis through the tip post 244), as shown in FIG. The proximal portion 249 of the crimp recess 245 is shown to include a portion radius that may have dimensions the same as and / or similar to the portion radius of the distal portion 247. Additionally, the dimensions (e.g., depth, length, etc.) of the crimp recess 245 may be similar to those of the crimp recess 145 as shown and described with reference to the implant 100.

[0087] Anchor portion 130 is further illustrated in FIGS. 36-38 as including a lateral removal feature 296 disposed about the exterior surface of release coupling portion 238. In some embodiments, lateral removal feature 296 may have a geometry similar to lateral removal feature 196 of implant 100. Lateral removal feature 296 may be configured to have an irregular or non-circular cross-sectional shape (e.g., hexagonal, convex and / or concave, etc.) to accommodate one or more instruments that facilitate lateral removal of anchor portion 130. As shown in FIGS. 36-38 , lateral removal feature 296 is disposed immediately adjacent to circumferential groove 292 and directly distal to the threads of threaded shaft portion 132. Lateral removal feature 296 may have a length along the longitudinal axis of implant 200 that is less than the length of lateral removal feature 196 along the longitudinal length of implant 100. Thus, the reduced length of lateral removal feature 296 can complement the increased longitudinal length of circumferential groove 292. Furthermore, lateral removal feature 296 can include openings 295 (e.g., recesses, holes, detents, etc.) extending radially / diametrically from a surface of lateral removal feature 296 into and / or through release coupling portion 238. Openings 295 can be configured to accommodate one or more instruments and / or methods for implanting and / or removing anchor portion 130 from a patient. Anchor portion 130 is further illustrated as including openings 297 (e.g., recesses, holes, detents, etc.) extending radially / diametrically from a surface of threaded shaft portion 132 into and / or through threaded shaft portion 132. Openings 297 can be configured to accommodate one or more instruments and / or methods for implanting and / or removing anchor portion 130 from a patient. In some embodiments, openings 295, 297 can be configured to facilitate sterilization and / or other similar procedures. For example, openings 295, 297 may be configured to receive ethylene oxide gas or other sterilizing gas to facilitate sterilization of the internal components of implant 200. In some embodiments, implant 200 may include three or more openings the same and / or similar to openings 295, 297, with the openings variously positioned around implant 200 and its components.

[0088] Anchor portion 132 is further illustrated as including a crimping portion 233 at the distal end of anchor portion 130 (e.g., disposed on the opposite side of anchor portion 130 from release coupling portion 238). Crimping portion 233 is configured with an intermediate removal mechanism 298 configured to facilitate intermediate removal of anchor portion 130 of implant 200 (e.g., after fracture of release portion 260 of implant 200). Crimping portion 233 is illustrated as having a flat surface disposed directly adjacent threaded shaft portion 132, with intermediate removal mechanism 298 disposed on the opposite side of the threaded shaft portion from the flat surface. In some embodiments, intermediate removal mechanism 298 may have a geometry similar to intermediate removal mechanism 198 of implant 100. Intermediate removal mechanism 298 can be configured to have an irregular or non-circular cross-sectional shape (e.g., hexagonal, convex and / or concave, etc.) and accommodate one or more instruments to facilitate intermediate removal of anchor portion 130.

[0089] With reference to implants 100, 200 and their components, all of which may be constructed of one or more of the same and / or similar materials previously identified. Implant 200 may also be configured to have the same or similar dimensions (e.g., length, cross-sectional width, circumference, diameter, etc.) as implant 100. Furthermore, implant 200 may be implemented in a surgical procedure in the same or similar manner as implant 100, which may include, for example, following the same / similar steps for the surgical procedure and / or using the same / similar instruments.

[0090] The assembled implant 100, 200 can then be implanted into the first and second bones / bone segments. For example, the assembled implant 100 can be implanted or inserted into the first and second bones, with the breakaway portion 120 positioned at least partially within the joint or space between them. As described above, the breakaway portion 120 does not ultimately leave the head portion 110 connected to the anchor portion 130 solely by the constraint and / or tensioning member 150. The breakaway portion 120 can fail, for example, after the bone / implant 100 has been physiologically loaded. Failure of the breakaway portion 120 allows semi-constrained movement between the first and second bones via the constraint and / or tensioning member 150 and at least one elastic member 151. The flexibility of the at least one elastic member 151 (and potentially the constraint and / or tensioning member 150) can enable distraction movement of the implant 100. Thus, the implant 100 allows for, for example, the restoration of physiological movement in the patient and allows for, for example, diastasis movement and / or pressure spikes.

[0091] As will be apparent to those skilled in the art based on the teachings herein, numerous variations and modifications can be made to the above-described and other embodiments of the present disclosure without departing from the scope of the present disclosure. The head members, anchor members, tension members, links, and other components of the implants and / or systems as disclosed herein, including the accompanying abstract and drawings, may be substituted with alternative components or features, such as those disclosed in other embodiments, that serve the same, equivalent, or similar purpose as known to those skilled in the art, achieve the same, equivalent, or similar result, and provide similar functionality for their intended purpose. Furthermore, the implants and / or systems may include more or fewer components or features than the embodiments described and illustrated herein. Accordingly, the detailed description of the presently preferred embodiments should be interpreted as illustrative, as opposed to restrictive, of the present disclosure.

[0092] Similarly, positions or orientations may be used herein with reference to anatomical structures or surfaces. Furthermore, the implants, devices, instruments, and methods, as well as aspects, components, features, etc., disclosed herein are described with reference to one side of the body for simplicity. However, because the human body is relatively symmetrical or mirror-imaged about a line of symmetry (the midline), it is expressly contemplated that the implants, devices, instruments, and methods, as well as aspects, components, features, etc., described and / or illustrated herein may be changed, altered, modified, reconfigured, or otherwise modified for use with or in connection with the other side of the body for the same or similar purposes without departing from the spirit and scope of the present invention. For example, implants, devices, instruments, and methods, as well as aspects, components, features, etc., described herein with respect to the right leg may be mirrored to function similarly with the left leg. Furthermore, while the components, devices, instruments, and methods, as well as aspects, components, features, etc., disclosed and described herein are described with respect to the leg for simplicity, it should be understood that the components, devices, instruments, and methods can be used with other bones of the body having similar structures.

[0093] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. The terms "comprise," "comprises," "comprising," etc., "have," "has," "having," "include," "includes," "including," "contain," "contains," "containing," etc." are understood to be open-ended linking verbs. Consequently, a method or device that comprises, has, includes, or contains one or more steps or elements may possess those one or more steps or elements, but is not limited to possessing only those one or more steps or elements. Similarly, a method step or device element that comprises, has, includes, or contains one or more features may possess those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a particular way is configured in at least that way, but may also be configured in ways not listed.

[0094] The present disclosure has been described with reference to preferred embodiments. It will be understood that the structural and operational embodiments described herein are illustrative of multiple possible configurations for providing the same general features, characteristics and general system operation. Modifications and alterations will occur to others upon reading, understanding and understanding the foregoing detailed description. It is intended that the present disclosure be construed to include all such modifications and alterations.

Claims

1. a head portion at a proximal end of the implant, the head portion including external threads and a first axial throughbore; an anchor portion at a distal end of the implant extending from the head portion, the anchor portion including external threads and a second axial throughbore communicating with the first axial throughbore; a flexible restraining member extending within the first axial throughbore and the second axial throughbore, the flexible restraining member including a first end connected to the head portion and a second end connected to the anchor portion; at least one of the head portion and the anchor portion forms a breakaway portion configured to concentrate stress such that a force acting on the implant causes the implant to break at the breakaway portion, separating the head portion and the anchor portion; the breakaway portion includes an outer circumferential groove and an inner circumferential groove axially aligned with the outer circumferential groove, the inner circumferential groove being at least partially defined by an inner end surface portion of the head portion and an inner end surface portion of the anchor portion; The implant, wherein the head portion and the anchor portion are welded together at a weld zone positioned axially adjacent the outer circumferential groove and the inner circumferential groove.

2. the inner end surface portion of the head portion includes an arcuate inner end surface portion of the head portion; The implant of claim 1 , wherein the anchor portion inner end surface portion comprises an arcuate anchor portion inner end surface portion.

3. the inner end surface portion of the head portion includes a chamfered inner end surface portion of the head portion; The implant of claim 1 , wherein the inner end surface portion of the anchor portion comprises a chamfered inner end surface portion of the anchor portion.

4. the proximal end of the anchor portion includes a connecting cavity; a distal end of the head portion including a coupling protrusion corresponding to the coupling cavity; The implant of any one of claims 1 to 3, wherein the connecting projection is received within the connecting cavity.

5. a bottom of the interlocking cavity defining an inner end surface portion of the anchor portion; The implant of claim 4 , wherein a tip portion of the connecting projection defines an inner end surface portion of the head portion.

6. The implant of claim 4 , wherein the interlocking cavity and the interlocking projection are secured together at the weld zone.

7. The implant according to any one of claims 1 to 5, wherein the head portion and the anchor portion are fixed together at the weld zone.

8. The implant of claim 7 , wherein the head portion and the anchor portion are laser welded together at the weld zone.

9. The implant of claim 7 , wherein the weld zone includes an interlocking projection and an interlocking cavity welded together.

10. The implant of any preceding claim, wherein the flexible restraining member comprises an elastic member.

11. The implant of any preceding claim, wherein the flexible restraining member comprises a suture loop.

12. 12. The implant of claim 1, further comprising a head post member held within the enlarged portion of the first axial throughbore, the head post member being coupled to a first end of the flexible restraining member.

13. The implant of claim 12 , further comprising a resilient member positioned within the enlarged portion of the first axial throughbore between a proximal end of the enlarged portion and the head post member.

14. a distal post member positioned within the second axial throughbore and fixedly connected to the anchor portion; The implant of any preceding claim, wherein the distal post member is connected to a second end of a flexible restraining member.

15. The implant of claim 14 , wherein the distal end of the tip post member includes at least one hook.

16. the distal post member includes an exterior crimp groove; The implant of any preceding claim, wherein the proximal connecting portion of the anchor portion deforms into the external crimp groove.

17. The head part is a shaft portion having a first end and a second end; a head extending from a first end of the shaft portion; and a first breakaway coupling portion extending from the second end of the shaft portion.

18. 18. The implant of claim 17, wherein a portion of the shaft portion of the head portion includes external threads.

19. 19. An implant according to claim 17 or 18, wherein the head includes a non-circular drive opening at a free axial end thereof, the non-circular drive opening forming part of the first axial throughbore.

20. 20. The implant of any one of claims 17 to 19, wherein the first breakaway coupling portion includes a coupling protrusion having an inner surface that defines an inner end surface portion of the head portion, the inner surface of the coupling protrusion forming part of the first axial through hole.

21. 21. The implant of claim 20, wherein the first breakaway coupling portion further comprises a stop surface extending radially from an outer surface of the coupling projection and positioned axially between an inner end surface portion thereof and the head.

22. 22. The implant of claim 21, wherein the anchor portion has at its first end a second release coupling portion including a coupling cavity with an inner bottom surface defining an inner end surface portion of the anchor portion, and the inner surface of the coupling protrusion forms part of the first axial through bore.

23. 23. The implant of claim 22, wherein the interlocking projection fits within the interlocking cavity.

24. 24. The implant of claim 23, wherein the interlocking projection and interlocking cavity are fixed together.

25. 24. An implant according to claim 22 or 23, wherein an end face of the second release link abuts a stop face of the first release link.

26. The anchor part further a shaft portion having a first end and a second end; a crimp portion extending from the second end; The implant of any of claims 22 to 25, wherein a second release connection extends from the first end of the shaft portion.

27. 27. The implant of claim 26, wherein a portion of the shaft portion of the anchor portion includes external threads.

28. 28. The implant of claim 26 or 27, wherein the proximal portion of the shaft portion includes a plurality of outer planar surfaces arranged circumferentially around the proximal portion that form the proximal external drive mechanism.

29. An implant according to any of claims 26 to 28, wherein the crimped portion comprises a plurality of outer planar surfaces arranged circumferentially around the crimped portion forming the distal external drive mechanism.

30. the first axial throughbore in the head portion includes a first enlarged portion positioned proximate the head portion and a second narrowed portion positioned proximate the breakaway portion; 30. The implant of any preceding claim, further comprising a head post member positioned within the first enlarged portion of the first axial throughbore and coupled to a first end of the flexible restraining member.

31. 31. The implant of claim 30, further comprising at least one resilient member axially positioned within the first enlarged portion of the first axial throughbore between the second narrow portion thereof and the head post member.

32. 32. The implant of claim 31, wherein the second narrow portion, the at least one resilient member, and the head post member are configured such that the at least one resilient member and the head post member are prevented from axially translating through the second narrow portion.

33. 33. The implant of claim 31 or 32, wherein the at least one resilient member comprises at least one tube formed of thermoplastic urethane, polycarbonate urethane, or a combination thereof.

34. The implant of any preceding claim, wherein the flexible restraining member comprises a suture.

35. The implant of any preceding claim, wherein the flexible restraining member comprises a loop.

36. An implant according to any preceding claim, wherein the head portion, the breakaway portion and the anchor portion are integral.

37. The implant of any one of claims 1 to 36, wherein the implant is integrated.

38. An implant according to any preceding claim, comprising a cannula opening extending through the entire axial length of the implant.

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