WO2016044728A1

WO2016044728A1 - Fusion devices, systems and related methods

Info

Publication number: WO2016044728A1
Application number: PCT/US2015/050948
Authority: WO
Inventors: James C. Barnitz; Michael J. Rello; Richard M. Jay
Original assignee: Proception Medical, Llc
Priority date: 2014-09-18
Filing date: 2015-09-18
Publication date: 2016-03-24

Abstract

The present disclosure provides devices, systems and methods for the fusion of first and second bone or tissue segments. The devices and systems include first and second attachment members configured to couple within the first and second bone or tissue segments, respectively. The devices and systems may also include a plug member and a resilient member, in a compressed state, positioned within the second attachment member between a substantially closed end and the plug member. The devices and systems may further include an actuation member translatably coupled within the first attachment member, and at least one coupling member extending into the first attachment member, at least one slot of the second attachment member, and an aperture of the plug member.

Description

FUSION DEVICES, SYSTEMS AND RELATED METHODS CROSS REFERENCE TO RELATED APPLICATION

[0001] This international PCT application claims priority to U.S. Provisional

Patent Application No. 62/091 ,144 filed December 12, 2014, and entitled "Bone Fusion Devices, Systems and Related Methods," which claims priority to U.S.

Provisional Patent Application No. 62/052,246 filed on September 18, 2014, and entitled "Bone Fusion Devices, Systems and Related Methods," which claims priority to U.S. Provisional Patent Application No. 61/938,274 filed on February 1 1 , 2014, and entitled "Interphalangeal and Metatarsophalangeal Joint Fusion System Implant and Related Methods," the entirety of which are hereby included herein by reference.

FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to bone or tissue fusion systems, devices, and methods that promote fusion of bone or tissue segments.

BACKGROUND OF THE INVENTION

[0003] An ideal fusion of bone or tissue segments is facilitated by solid and sustained contact at the conclusion of a surgical procedure and also keeping sustained contact and compression for a period of time following the surgical procedure for the healing process to unite the segments. Failure to maintain proper fixation to keep sustained contact, under compression, can result in malunion, nonunion, misalignment and ongoing pain for a patient.

[0004] Bone or tissue segments are fused for a variety of reasons or medical treatments. As a result, bone or tissue fusion is an extremely common procedure performed in millions of surgical procedures annually. Many ailments, diseases, traumas, fractures or abnormalities require, or are treated by, bone or tissue fusions. For example, osteotomies, wherein adjacent bone segments are cut, repositioned and arranged to fuse together into a new position are commonly utilized to treat angular abnormalities, fractures and various trauma procedures.

[0005] Unfortunately, current compression systems, devices and methods do not adequately or efficiently promote healing or fusion of bone or tissue segments. As a result, there is a need for improved continued compression devices, implants, systems and related methods to promote the healing or fusion of bone or tissue segments. SUMMARY

[0006] The present disclosure facilitates secure fixation of first and second bone or tissue segments, such as first and second sections or fragments of a single bone, or separate and distinct first and second bones, to promote fusion there between. Before implantation of the devices and systems described herein, at least one of a first bone or tissue segment and a second bone or tissue segment may be cut. In alternative embodiments, at least one of the first and second bone or tissue segments may not be cut. In some embodiments, the first and second bone or tissue segments may be segments of a bone fracture, and the devices and systems may be utilized for fracture fixation and, thereby, fusion. A device or system of the present disclosure may be implanted (e.g., intramedullary) into first and second bone or tissue segments to reconnect the bone or tissue segments into a corrective construct that applies continued compression of the fusion site during at least the first several weeks of healing after surgery.

[0007] For example, in one aspect the present disclosure provides a bone or tissue compression device that includes a first attachment member that is configured to be secured within a first bone or tissue segment and includes a first cavity, a first end and a second end and at least one first aperture that extends into the first cavity between the first and second ends. The bone tissue compression device may also include a second attachment member that is configured to couple within a second bone or tissue segment and may include a second cavity, a substantially closed first end, a second end, and at least one slot that extends into the second cavity between the first and second ends in which the second attachment member is positioned partially within the first cavity of the first attachment member and may extend through the second end. The bone tissue compression device may further include a plug member that has a first end and a second end and at least one second aperture that is between the first and second ends. The plug member may be positioned within the second cavity of the second attachment member and at least partially within the first cavity of the first attachment member. The bone tissue compression device may also have a resilient member, in a compressed state, positioned within the second cavity of the second attachment member positioned between the substantially closed first end of the second attachment member and the first end of the plug member. Additionally, the bone tissue compression device may have an actuation member moveably and/or translatably coupled within the first cavity of the first attachment member and at least one coupling member that extends into the at least one first aperture of the first attachment member, the at least one slot of the second attachment member, and the at least one second aperture of the plug member.

[0008] In another aspect, the present disclosure provides a bone or tissue fusion device that includes a first assembly that has a latch with at least one deflectable arm and a pawl positioned on it, a resilient member in a first compressed state, a retainer positioned between the latch and the resilient member and a first attachment member that is constructed to couple within a first bone segment and includes a first cavity and at least a one slot extending into the first cavity in which the latch, retainer and resilient member are slidably coupled within the first cavity. The pawl may be positioned within the at least a one slot. The bone or tissue fusion device may also include a second assembly that has a second attachment member configured to be attached within the second bone segment and may include a second cavity. The bone or tissue fusion device may also have a pin extending into the second cavity in which the first assembly is slidably received within the second cavity of the second assembly such that the pawl of the first assembly may engage the pin of the second assembly. The bone or tissue fusion device is configured to be activated so that the resilient member expands from the first compressed state to a second less compressed working state to force the latch toward the first bone segment and thereby pull the second assembly toward the first assembly resulting in a compressive load.

[0009] These and other objects, features and advantages of this disclosure will become apparent from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a perspective exploded view of fusion device or system according to the present disclosure;

[0011] FIG. 2 is a perspective exploded view of the fusion device or system of

FIG. 1 partially assembled first and second bone or tissue segments;

[0012] FIG. 3 is perspective view of the fusion device or system of FIG. 1 assembled and in a loaded state;

[0013] FIG. 4 is perspective view of the fusion device or system of FIG. 1 implanted in first and second segments and in a loaded state;

[0014] FIG. 5 is cross-sectional view of the fusion device or system of FIG. 1 implanted in first and second segments and in a loaded state;

[0015] FIG. 6 is cross-sectional view of the fusion device or system of FIG. 1 implanted in first and second segments and in an activated compression state;

[0016] FIG. 7 is a perspective exploded view of another fusion device or system according to the present disclosure;

[0017] FIG. 8 is top and side exploded views of the fusion device or system of FIG. 7;

[0018] FIG. 9 is top and side views of the fusion device or system of FIG. 7 partially assembled;

[0019] FIG. 10 is a perspective view of the fusion device or system of FIG. 7 partially assembled and implanted in first and second bone or tissue segments;

[0020] FIG. 1 1 is a top view of the fusion device or system of FIG. 7 partially assembled and implanted in first and second segments;

[0021] FIG. 12 is a side cross-sectional view of the fusion device or system of

FIG. 7 partially assembled and implanted in first and second segments;

[0022] FIG. 13 is a perspective view of the fusion device or system of FIG. 7 implanted in first and second bone segments and assembled in a loaded state;

[0023] FIG. 14 is a top view of the fusion device or system of FIG. 7 implanted in first and second bone segments and assembled in a loaded state;

[0024] FIG. 15 is a side cross-sectional view of the fusion device or system of

FIG. 7 implanted in first and second bone segments and assembled in a loaded state;

[0025] FIG. 16 is a perspective view of the fusion device or system of FIG. 7 implanted in first and second segments and in an activated compression state;

[0026] FIG. 17 is a top view of the fusion device or system of FIG. 7 implanted in first and second segments and in an activated compression state;

[0027] FIG. 18 is a side cross-sectional view of the fusion device or system of

FIG. 7 implanted in first and second segments and in an activated compression state;

[0028] FIG. 19 is a side exploded view of another fusion device or system according to the present disclosure;

[0029] FIG. 20 is a perspective exploded view of the fusion device or system of FIG. 19;

[0030] FIG. 21 is a cross-sectional exploded view of the fusion device or system of FIG. 19;

[0031] FIG. 22 is a top view of the fusion device or system of FIG. 19 in an assembled and loaded state;

[0032] FIG. 23 is a perspective view of the fusion device or system of FIG. 19 in an assembled and loaded state;

[0033] FIG. 24 is a cross-sectional view of the fusion device or system of FIG.

19 in an assembled and loaded state;

[0034] FIG. 25 is a top view of the fusion device or system of FIG. 19 in an activated state;

[0035] FIG. 26 is a perspective view of the fusion device or system of FIG. 19 in an activated state; and

[0036] FIG. 27 is a cross-sectional view of the fusion device or system of FIG.

19 in an activated state.

DETAILED DESCRIPTION

[0037] The devices, systems and methods disclosed herein are configured to yield continuous compression between two bone or tissue segments. The devices, systems and methods may be utilized with any bone or tissue segments. For example, the devices, systems and methods disclosed herein may be used in any fusion, fracture or osteotomy site, for example, that allows the entrance and/or insertion of the devices and systems into first and second bone or tissue segments.

[0038] For bone or tissue segments that do not provide, or not adequately provide, for the entrance and insertion of the disclosed devices and systems fully therein, for example, the shape, size, form and/or configuration of the devices and systems can be altered from the illustrated exemplary embodiments shown herein without departing from the spirit and scope of the disclosure. For example, while the shape, size, thread design, implant form and/or configuration of the devices and systems may be altered from the exemplary embodiments shown herein to suit the anatomy and/or structure of particular first and second bone or tissue segments. However, in whatever configuration, form or size, the devices and systems disclosed herein, the devices and systems may utilize a compressed resilient member to achieve continued compression of first and second bone or tissue segments.

[0039] It is noted that at least some of the designs or configurations of the exemplary illustrated fusion system and devices shown and described herein may be particularly well adapted or advantageous (e.g., without substantial re-design of shape, size, form, etc.), for example and without limitation, to first MPJ fusions, first IPJ fusions, lessor MPJ fusions, transverse metatarsal fracture fusions, lapidus 1 st/cuneiform fusions, lis franc met/cunio and cuboid fusions, digital fusions, and/or related hand bone segment fusions. Some bone or tissue segment fusions that may necessitate or benefit from modifications (e.g., modifications to the shape, size, form, etc. that do not depart from the spirit and scope of the disclosure) of the exemplary illustrated fusion system and devices embodiments shown and described herein may include fibula fracture fusions (distal - central - proximal), tibial malleolar fracture fusions, ankle fusions, talo-navicular fusions, calc-cuboid fusions, intra-medullary radial type fusion procedures of the tibia, fibula or femur, and related upper extremity fusion procedures.

[0040] The fusion devices, systems and methods of the present disclosure provide a continued compression implant that provides innovative, intramedullary, constant, and static compression along a fusion site throughout the entire process of healing. In one embodiment, as shown in FIGS. 1 -6 and described further below, the implant may include a two-piece subassembly that forms a bone screw design. The device or implant may include an internal compression resilient member that provides constant compression to the fusion site of the first and second segments to facilitate fusion or healing thereof. The device or implant may be configured such that the implant is positioned intramedullary to isolate the implant from local anatomical structures (and vice versa). The device or implant may also be configured to be reversible and/or adjustable such that a surgeon can customize, tailor and/or adjust the device or implant to provide efficient and effective fusion. The device or implant may also be formed in a variety of size ranges, shapes, forms or other exterior configurations (such as in a kit) to allow the implant to be used in a wide array of patients and/or applications. Still further, the device or implant may include less complicated hardware (e.g., activation via simple removal of a pin) than standard or typical devices.

[0041] As shown in FIGS. 1 -6, in some embodiments, the fusion devices, systems and methods of the present disclosure may include a two-piece device, system or implant 10 including a first or distal segment assembly or implant 12 and a second or proximal segment assembly 14. Both the first assembly 12 and the second assembly or implant 14 may include a plurality of components, portions or aspects. The first assembly 12 may be configured to be implantable and engageable within (e.g., intramedullary), at least partially, a first or distal segment 16, such as a first bone segment. Similarly, the second assembly 14 may be configured to be implantable and engageable within (e.g., intramedullary), at least partially, a second or proximate segment 18, such as a second bone segment. Once

implanted, the implant 10 may span a junction or fusion site 20 between the first 16 and second 18 segments, as shown in FIGS. 4-6. It is noted that the terms "distal" and "proximal" or used herein only as relative terms, and that, alternatively, the implant or bone or tissue segments may be reoriented such that the implant or segments extend in a substantially opposing direction as compared to that shown and described herein (i.e., the first or distal assembly 12 and first or distal segment 16 may be positioned proximate to the second or proximal assembly 14 and second or proximate segment 18, respectively).

[0042] The second assembly 14 may include at least two separate and distinct components or aspects. For example, the second assembly 14 may include at least one latch locking pin 22 and a second or proximal engagement member 24. As shown in FIGS. 1 -3, 5 and 6, the second engagement member 24 may be hollow or otherwise include an internal cavity or space 26. The second engagement member 24 may include a substantially closed end 25 and a substantially open end that allows for access to the internal cavity 26. The second engagement member 24 may be elongate such that the second engagement member 24 is implantable intramedullary, for example. In some embodiments, the second engagement member 24 is a substantially hollow cylindrical member or tube-like.

[0043] As shown in FIG. 4, the outer surface of the second engagement member 24 may include external threads configured such that the second

engagement member 24 may be screwed into the second segment 18, such as a bone segment. The external threads of the second engagement member 24 may be cancellous and/or cortical threads to secure the second assembly 14 tightly into the second or proximate segment 18.

[0044] The second engagement member 24 of the second assembly 14 may also include at least one aperture 28 extending from the exterior surface and into the internal cavity 26 thereof. The aperture 28 may be configured to allow for the latch locking pin 22 to be received within the aperture 28 and extend into the internal cavity 26, as shown in FIGS. 3, 5 and 6. The latch locking pin 22 and/or the aperture 28 may be configured such that the latch locking pin 22 is secured within the aperture 28 when the latch locking pin 22 is received within the aperture 28. In some embodiments, the aperture 28 may be non-threaded. As explained further below, the portion of the latch locking pin 22 positioned within the cavity 26 of the second engagement member 24 may allow a portion of the first assembly 12 to engage the second assembly 14, provisional locking of the first and second segments 16, 18 and, ultimately, allow the first and second segments 16, 18 to be pulled (or pushed) together via a resilient member 40 to provide apposition and compression to the fusion site 20 between the first and second segments 16, 18.

[0045] The cavity 26 of the second engagement member 24 of the second assembly 14 may be configured to receive the first assembly 12 therein, as shown in FIGS. 1 -6. For example, the first assembly 12 may include a first engagement member 34 that is configured to be slidably received within the cavity 26 of the second engagement member 24 through the open end thereof. In some

embodiments the second engagement member 24 may receive and substantially center the first engagement member 34 within the second assembly 14. Similar to the second engagement member 24, the first engagement member 34 may be hollow or otherwise include an internal cavity or space 36. The first engagement member 34 may include a substantially closed end 35 and a substantially open end that allows for access to the internal cavity 36. The first engagement member 34 may be elongate such that the first engagement member 34 is implantable intramedullary, for example. In some embodiments, the first engagement member 34 is a substantially hollow cylindrical member or tube-like.

[0046] As show in FIG. 4, the outer surface of the first engagement member

34 may include external threads configured such that the first engagement member 34 may be screwed into the first segment 16, such as a bone segment. The external threads of the first engagement member 34 may be cancellous and/or cortical threads to secure the first assembly 12 tightly into the first or distal segment 16, such as a bone segment.

[0047] The first engagement member 34 may include at least one slot 38, such as a pair of substantially opposing slots 38, that is positioned proximate to the closed end 35 and that extends from the exterior surface and into the cavity 36, as shown in FIGS. 3, 5 and 6. The at least one slot 38 may extend axially in a direction extending substantially between the open end and the closed end 35 of the first engagement member 34. The at least one slot 38 may be configured to accept the portion of the latch locking pin 22 positioned within the cavity 26 of the second engagement member 24 into the slot 38 when the first engagement member 34 is received within the cavity 26 of the second engagement member 24. When the first engagement member 34 is received within the second engagement member 24 and the latch locking pin 22 is positioned within the slot 38, the first and second assemblies or implants 12, 14 may be considered coupled or connected, and the slot 38 and the latch locking pin 22 may substantially prevent relative rotation of the assemblies 12, 14. However, the slot 38 allows for axial sliding translation of the latch locking pin 22 within the slot 38, and thereby allows or provides for axial sliding translation of the first and second assemblies 12, 14 along the length of the slot 38 with respect to each other. As explained further below, the at least one slot 38 may also be configured to accept a pawl or tooth 64 of a latch 60 therein to engage the latch locking pin 22 of the second assembly 14.

[0048] As shown in FIGS. 1 -6, the first attachment assembly 12 may include a resilient member or element 40, a latch member 60 and a resilient member retainer member 50 housed or provided within the cavity 36 of the first engagement member 34. The resilient member 40 may be positioned between the closed end 35 of the first engagement member 34 and the retainer member 50, as shown in FIGS. 1 -3, 5 and 6. The first engagement member 34 may be configured to resist bending, deflection or other otherwise interfering with the compression (or contraction) of the resilient member 40 within the cavity 36. The resilient member 40 may be at least one spring member, resilient material, polymer or any other mechanism or material that is elastically deformable or is otherwise capable of storing mechanical energy that substantially opposes compression thereof. In the illustrated embodiment, the resilient member 40 is a plurality of stacked Bellville springs or washers. The resilient member 40 may provide the mechanical function of the device or implant 10. The resilient member 40 may be configured in various sizes, and provide for a range of displacements, spring constants or the like, and such may be based on the orthopedic application, force needed and distance traveled (as explained further below).

[0049] With reference to FIGS. 1 -3, 5 and 6, the latch 60 may be positioned within the cavity 36 of the first attachment member 34 and between the bone member 16 and the retainer 50. The latch 60 may include at least one arm 62 extending toward the closed end 35 or the at least one slot 38 of the first attachment member 34. In some embodiments the latch 60 includes a pair of substantially opposing arms 62. The at least one arm 62 of the latch 60 may define a free end and may be deflectable or flexible (e.g., resiliently deformable) in compression towards the interior of the cavity 36. The at least one arm 62 may include an outwardly extending pawl or tooth 64 at the free end thereof. The pawl 64 of the arm 62 may be configured such that when the latch 60 is retained within the cavity 36 of the second attachment member 34, and the second attachment member 34 is received within the cavity 26 of the first attachment member 24, the at least one arm 62 is positioned within the at least one slot 38 and the pawl 64 engages the latch locking pin 22 within the slot 38. The front portion of the pawl 64 may be angled or otherwise configured to allow the first assembly 12 to be slidably translated into the cavity 36 of the second assembly 14 such that the at least one arm 62 is deflected or compressed and the pawl 64 passes over the latch locking pin 22. Stated differently, the at least one arm 62 may be flexible and compressible when driven past the latch locking pin 22 located in the second attachment member 24. Once positioned past the latch locking pin 22 (i.e., proximal to the closed end 35) (see FIGS. 5 and 6), the pawl 64 may be configured such that the latch locking pin 22 prevents the latch 60 from slidably translating out of the cavity 36 of the second assembly 14.

[0050] As the latch 60 may be slidably coupled or fixed within the first attachment member 34 via a latch retaining pin 70, once the pawl 64 is positioned past the latch locking pin 22 (see FIGS. 5 and 6) the latch locking pin 22 prevents the first attachment assembly 12 and the second assembly 14 from being decouple or detached (i.e., prevents disengagement of the first and second attachment assemblies 12, 14 once coupled or connected). However, the device or implant 10 may be configured that the at least one arm 62 of the latch 60 can be manually compressed or deflected inwardly, with an instrument for example, to allow for the first and second attachment assemblies 12, 14 to disengage if necessary (i.e., deflect the at least one arm 62 inwardly such that the corresponding pawl(s) is able to move past the latch locking pin 22).

[0051] As noted above, the first attachment assembly 12 may include a latch retaining pin 70. As shown in FIGS. 1 -3, 5 and 6, the second attachment member 34 may include an at least one aperture 72 extending from the exterior surface of the first attachment member 34 into the first cavity 36 thereof. The least one aperture 72 may be configured to receive the latch retaining pin 70 there through. The latch 60 may also include at least one slot 74 configured to receive the latch retaining pin 70 therein when the latch retaining pin 70 extends through the least one aperture 72 of the first attachment assembly 12 and the latch 60 is positioned within the cavity 36 of the first attachment member 34. In this way, the latch retaining pin 70 may extend through the first attachment assembly 12 and into the at least one slot 74 of the latch 60 to slidably couple or fix the latch 60 and the first attachment assembly 12. As the retainer 50 and the resilient member 40 are positioned between the end 35 of the first attachment member 34 and the latch 60, the latch retaining pin 70 and at least one slot 74 of the latch 60 may limit the axial movement of each of the latch 60, the retainer 50 and the resilient member 40 within/ with respect to the first attachment member 34. Further, when the pawl 64 of the at least one deflectable arm 62 is positioned past the latch locking pin 22, the latch retaining pin 70 and at least one slot 74 of the latch 60 may limit the axial movement of the first assembly 12 with respect to the second assembly 14. For example, the latch locking pin 22 may provide a hard stop if the first and second bone assemblies 12, 14 are pulled apart. Further, the latch retaining pin 70 and at least one slot 74 of the latch 60 may act to limit the space or distance between the latch 60 and the closed end 35 of the first attachment member 34.

[0052] The retainer 50 and the resilient member 40 may be positioned between the end 35 of the first attachment member 34 and the latch 60, with the resilient member 40 being positioned between the end 35 and the latch 60, as FIGS. 1 -3, 5 and 6. The retainer 50 may thereby effectively couple the resilient member 40 to the latch 60. The retainer 50 may improve the manufacturability of the device or implant 10 as it allows for a simpler design of the latch 60 and a reduction of the overall cost of the device 10. The retainer 50 may prevent the resilient member 40 from backing out of the cavity 36 of the first attachment member 34 toward the open end thereof (or otherwise moving within the cavity 36). As also shown in FIGS. 1 -3, 5 and 6, the retainer 50 may include a channel 52 corresponding to each of the at least one arm 62 of the latch 60. The channel(s) 52 of the retainer 50 may prevent the at least one arm 62 from being overly compressed, such as during disassembly (as discussed above).

[0053] The retainer 50 may further include at least one aperture 82 extending from the exterior surface of the retainer 50 and at least partially there through, as FIGS. 1 -3, 5 and 6. The at least one aperture 82 may be configured to removably receive a retracting pin 80 therein. The first attachment member 34 may similarly include at least one aperture 84 extending from the exterior surface of the first attachment member 34 and into the cavity 36 thereof. The at least one aperture 84 may be configured to removably receive the retracting pin 80 therein, and may be configured to substantially align when the retainer 50 is positioned within the cavity 36 of the first attachment member 34. In this way, when the first assembly 12 is removably received within and coupled to the second assembly 14 (via the at least one arm 62 of the latch 60 and the latch locking pin 22), the retracting pin 80 may extend through the first attachment member 34 and the retainer 50 to substantially fix the retainer 50 and the first bone attachment member 34 to each other.

[0054] As shown in FIG. 5, the device or implant 10 may be configured such that when the first assembly 12 is removably received within and coupled to the second assembly 14 (via the at least one arm 62 of the latch 60 and the latch locking pin 22), and the retracting pin 80 substantially fixes the retainer 50 and the first bone attachment member 34 to each other, the resilient member 40 may be compressed into a first or maximum compression state between the retainer 50 and the end 35 of the first attachment member 34, as shown in FIG. 5. The retracting pin 80 may thereby temporality hold or load the resilient member 40 in the first compression state. In such a position of the first assembly 34 and during the first compression state of the resilient member 40 (FIG. 5), the device or implant 10 may be configured such that the retaining pin 70 is located within the at least one slot 74 of the latch 60 at a position that allows the retainer 60 (and thereby the first attachment member 34) to translate within the cavity 36 toward the first bone 16, and the latch locking pin 22 is located within the at least one slot 38 of the first attachment member 34 at a positioned that allows the second attachment member 24 to translate toward the first segment 16 (or the first attachment member 34 to translate toward the second segment 18). Further, when the retracting pin 80 substantially fixes the retainer 50 and the first attachment member 34 (the first compression state of the resilient member 40) and the first and second assemblies 12, 14 are coupled 40 (FIG. 5), the device or implant 10 may be configured such that the end 35 of the first attachment member 34 is spaced from the end 25 of the second attachment member 24 to allow axial translation of the second assembly 14 toward the first segment 16 (or the first assembly 12 toward the second segment 18).

[0055] From the "loaded" position or state of the device or implant 10 shown in FIG. 5, the retracting pin 80 may be removed from the first attachment member 34 and the retainer 50, as shown in FIG. 6, to "activate" the device or implant 10.

Removal of the retracting pin 80 allows the resilient member 40 to release its stored energy (from the first compression state) and force the retainer 50 away from the second segment 18. As the retainer 50 abuts the latch 60, removal of the retracting pin 80 allows the resilient member 40 to expand from the first maximum compression state to a second working compression state to force the latch 60 away from the second segment 18. As the pawl(s) 64 of the latch 60 are coupled to the second assembly 14 via the latch locking pin 22 thereof, expansion of the resilient member 40 forces the retainer 50 away from the second segment 18 such that the pawl(s) 64 pull the locking pin 22 through the at least one slot 38 toward the first segment 16 (see, FIG. 5 as compared to FIG. 6). In this way, with the retracting pin 80 removed (and the device or implant 10 thereby activated), the resilient member 40 is able to expand from the first compression state (FIG. 5) to the working compression (FIG. 6) to "pull" the first and second assemblies 12, 14 together and, thereby, bring the first and second segments 16, 18 together to eliminate any gap at the fusion site 20 and provide compression to the fusion site 20 once the first and second segments 16, 18 are in abutment. As the device or implant 10 is configured such that even after the first and second assemblies 12, 14 have been pulled together and the first and second segments 16, 18 are in abutment (FIG. 5) the resilient member 40 is still in a compressed state (i.e., the working compression state of the resilient member 40), the resilient member 40 acts to apply a continued compression force to the fusion site 20 between the first and second segments 16, 18.

[0056] The continued compression fusion devices, systems and methods of the present disclosure may provide or facilitate effective and efficient fusion or healing between first and second segments (e.g., bone segments) through a variety of aspects or features of the devices and systems. For example, the two-piece threaded device or implant design of the fusion devices and systems of the present disclosure provides bone screw stability and a connection that creates a tight bone- to-bone apposition. As another example, the internal compression resilient member of the fusion devices and systems of the present disclosure provides autocorrects any gap that is formed post-surgery between the fusion site of the first and second segments and retains compression on the surgical site during healing. Still further, the bone screw portions (e.g., cortical- and cancellous-extending portions) of the fusion devices and systems of the present disclosure provide rigid placement of the device and fixation within the first and second segments without failure or micromotion (i.e., stable fixation). As yet another example, the intra-osseous design (configured to be completely contained within the first and second segments, as opposed to exterior to one of the segments) of the fusion devices and systems of the present disclosure prevent both short and long term soft tissue irritation post- implantation. Still further, the design of the fusion devices and systems of the present disclosure allow for simple insertion and limited bone or tissue segment cuts, which avoids undue trauma that could affect the blood flow to the fusion site.

[0057] A surgical technique or method of utilizing the fusion devices and systems described herein to promote fusion of first and second segments may include assembling the first and second assemblies or implants 12, 14. The method may also include coupling or implanting the assembled first assembly 12 within the first segment 16, and coupling the assembled second assembly 14 within the second segment 18. The method may further include removably coupling the assembled and implanted first assembly 12 with the assembled and implanted second assembly 14. Removably coupling the assembled and implanted assemblies 12, 14 may include axially translating or sliding the first assembly 12 within the cavity 36 of the second assembly 14 such that the at least one arms 62 are positioned within the at least one slot 38, are deflected by the latch locking pin 22, and are ultimately positioned between the latch locking pin 22 and the closed end 25 of the second attachment member 24.

[0058] The method may further include removing the retracting pin 80 from at least the retainer 50 to expand the resilient member 40 from the first compression state (FIG. 5) to the working compression state (FIG. 6) to force the retainer 50 away from the second segment 18 such that the pawl(s) 64 pull the locking pin 22 through the at least one slot 38 toward the first segment 16. Thereby, removing the retracting pin 80 from at least the retainer 50 may activate the device or implant 10 to "pull" the first and second assemblies 12, 14 together to eliminate any gap at the fusion site 20, abut the first and second segments 16, 18 at the fusion site 20, and provide continued compression to the fusion site 20.

[0059] In FIGS. 7-18, another exemplary continued compression bone fusion device, implant, system and method according to the present disclosure is indicated generally by the reference numeral 1 10. The device, implant or system or 1 10 is substantially similar to the device, implant or system or 10 described above with reference to FIGS. 1 -6, and therefore like reference numerals preceded by the numeral "1 " are used to indicate like elements, functions, aspects or the like (and therefore the corresponding description thereof presented above with respect to FIGS. 1 -6 equally applies to FIGS. 7-18). The device or implant 1 10 differs from the device or implant 10 with respect to the configuration of the first assembly 1 12.

[0060] As shown in FIGS. 7-18, the first assembly 1 12 does not include a retainer member positioned axially between the resilient member 140 and the latch 160. Rather, the latch 160 is elongated and includes an interior cavity or channel 190 and a substantially closed end 192 that is positioned proximate to the first segment 1 16. A "distal" portion of the resilient member 140 is carried or positioned within the cavity 190 of the latch 160, and a "proximal" portion of the resilient member 140 is carried or positioned within the cavity 126 of the second engagement member 124. In this way the resilient member 140 may extend between and abut the substantially closed end 192 of the latch 160 and the substantially closed end 135 of the first engagement member 134. The resilient member 140 may thereby "push" against the substantially closed end 192 of the latch 160 to move from the first compressed state to the second working state and "pull" the second assembly 1 14 via the pawl(s) 164 of the latch 160 when the retracting pin 180 is removed from the latch 160. Also, the resilient member 140 may thereby protect the at least one arm 162 from excessive inward deflection or compression.

[0061] As also shown in FIGS. 7-18, as the device, implant or system or 1 10 does not include a retainer member, the latch 160 may include at least one aperture 182 that is configured to align with the at least one aperture 184 of the second engagement member 124 and configured to receive the retracting pin 180 therein (to thereby temporarily couple the first assembly 1 12 and the second assembly 1 14 and "load" the device or implant 1 10). Further, the latch 160 and the first attachment member 134 may not be directly coupled by a pin or other member/mechanism (other than the temporary retracting pin 180 and the at least one arm 162 being positioned within the at least one slit 138) that limits the relative axial translation and/or rotation of the latch 160 and the first engagement member 134. For example, the device or implant 1 10 may not include a latch retaining pin, as described above, to limit the relative movement of the latch 160 and the first engagement member 134 (and thereby the first and second bone assemblies 1 12, 1 14). As shown in FIG. 18, after the retracting pin 180 has been removed and the device or implant 1 10 has been activated, the movement of the latch 160 may only be stopped or limited by the abutment of the first and second segments 1 16, 1 18 (and/or, potentially, the end of the at least one slot 138).

[0062] In FIGS. 19-27, another exemplary compression bone fusion device, implant, system and method according to the present disclosure is indicated generally by the reference numeral 210. The device, implant or system 210 is similar to the devices, implants or systems 10 and 1 10 described above with reference to FIGS. 1 -6 and FIGS. 7-18, respectively, and therefore like reference numerals preceded by the numeral "2", as opposed to "1 " for example, are used to indicate like elements, functions, aspects or the like (and therefore the corresponding description above equally applies to the device, implant or system 210 of FIGS. 19- 27). The device, implant or system 210 differs from the devices, implants or systems 10 and 1 10 with respect to its configuration, implantation and mode of actuation.

[0063] The device, implant or system 210 may be utilized in a variety of anatomical situations or needs with a variety of tissue or bone configurations to apply a compressive force to tissue or bone segments to promote stability and healing (e.g., bone fusion). For example, as further discussed below, the device, implant or system 210 may be particular effective in being driven through (e.g., screwed) or otherwise positioned across at least one junction between two or more tissue or bone segments (such as across a joint or fracture). After implantation, one end of the device, implant or system 210 may be accessed or manipulated (e.g., from or along the implantation pathway in which the device, implant or system 210 was driven or positioned within the tissue or bone segments) to "activate" the device, implant or system 210 and thereby apply the compressive force to the at least one junction of the tissue or bone segments.

[0064] As shown in FIGS. 19-27, the device, implant or system 210 includes a first attachment member 234, a second attachment member 224, a plug member 261 , a resilient member 240, an actuation member 281 , and at least one attachment or coupling member 222. As shown in the cross-sectional view of FIG. 21 , each of the first attachment member 234, second attachment member 224, plug member 261 and actuation member 281 includes or defines a cavity or interior space that accommodates at least one other component (as described in detail below).

[0065] The first attachment member 234 may be substantially hollow or otherwise configured to include a first cavity or interior space 236 accessible from a first open end 237, as shown in FIGS. 21 , 24 and 27. The first cavity 236 may be configured to slidably receive a portion of the second attachment member 224 therein (see FIGS. 22-27). As such, in some embodiments the interior surface of the first cavity 236 may be substantially smooth and/or sized, shaped or otherwise arranged to allow the second attachment member 224 to translate therein in a direction along the axial length of the first attachment member 234. The first attachment member 234 may also include at least one aperture 223 extending from the exterior surface of the first attachment member 234 and into the first cavity 236. The at least one aperture 223 may be configured to accept the at least one coupling member 222 member therein/there through such that the coupling member 222 is able to engage the second attachment member 224 (and any other component) positioned within the first cavity 236 (see FIGS. 24 and 27).

[0066] The first attachment member 234 may also be configured to include a second cavity or interior space 283 that is accessible from a second open end 239 that substantially opposes the first end open end 237 thereof, as shown in FIGS. 21 , 23 and 27. The first and second cavities 236, 283 may be contiguous or adjacent along the axial direction of the first attachment member 234 (see FIGS. 20, 24 and 27). Thereby, the first and second cavities 236, 283 may form portions or ends of a singular cavity within the first attachment member 234. The second cavity 283 may be configured to receive at least a portion of the actuation member 281 therein. As shown in FIGS. 21 , 24 and 27, the second cavity 283 may include threads that are configured to threadably mate with threads of the actuation member 281 , as shown in FIGS. 19-21 , 24 and 27.

[0067] As shown on FIGS. 19-27, the first attachment member 234 may include an expanded head portion 235 at the open second end 239. The expanded head portion 235 may act to engage or press against the bone or tissue segment in which it is inserted. In this way, the expanded head portion 235 at the open second end 239 of the first attachment member 234 may promote the compressive force to the fusion site after activation of the device 210, as described further below. As also shown in FIGS. 19-27, the free end of the portion 235 may include a groove, raised surface or other tool engagement surface feature for coupling with a tool to drive the device 210 through one or more bone or tissue segments. For example, at least the second attachment member 234 may include external threads that may act to translate the device into a bone or tissue segment via rotation. In this way, the tool engagement surface feature of the expanded head portion 235 at the open second end 239 of the first attachment member 234 may be configured to receive a torque applied by a tool to the device 210 to rotate the external threads of the at least the second attachment member 234 to drive or pull the device 210 into and/or through bone or tissue segments.

[0068] As also shown in FIGS. 19-27, the exterior surface of the first attachment member 234 between the expanded head portion 235 and the first open end 237 may be substantially smooth. The first attachment member 234 may thereby be void of external threads, and the external threads of the second attachment member 234 may be utilized to at least assist in seating the device 210 in first and second bone segments and across a joint extending there between. In alternative embodiments, the head portion 235 and/or the exterior surface of the first attachment member 234 between the expanded head portion 235 and the first open end 237 may include external threads.

[0069] As shown in the cross-sectional views of FIGS. 21 , 24 and 27, the actuation member 281 may also have a cavity 285 that is accessible from at least one outer axial end thereof. The cavity 285 of the actuation member 281 may be configured to mate with a tool device to facilitate rotation of the actuation member 281 (i.e., transfer a rotational force to the actuation member 281 ). In this way, when the actuation member 281 is at least partially threadably received and engaged within the second cavity 283 of the first attachment member 234, the actuation member 281 may be rotated via a tool within the cavity 238 and thereby threadably translated along the axis of the first attachment member 234 such that the actuation member 281 also extends into, or is fully removed from (depending upon the direction of rotation), the first cavity 236 of the first attachment member 234 (see FIGS. 24 and 27). In some embodiments, the cavity 285 of the actuation member 281 may be engaged by a tool or member extending through the open second end 239 of the first bone attachment member 234.

[0070] As also shown in the cross-sectional views of FIGS. 21 , 24 and 27, the second attachment member 224 may be substantially hollow or otherwise configured to include a third cavity or interior space 226 that is accessible from at least a first substantially open end 225. A second end 227 that axially substantially opposes the first end 225 of the second attachment member 224 may be at least partially closed and may form an end, at least partially, to the third cavity 226.

However, the second end 227 of the second attachment member 224 may include an aperture that allows access to the actuation member 281 in the first engagement member 234 from the first open end 225 and extend through the second attachment member 224. The third cavity 226 may be substantially smooth and/or sized, shaped or otherwise arranged or configured to slidably receive the resilient member 240 and the plug member 261 therein along the axial length of the second attachment member 224 (see FIGS. 24 and 27).

[0071] The second attachment member 224 may also include at least one slot 238 extending from the exterior surface of the second attachment member 224 and into the third cavity 226 along the axis of the second attachment member 224. The at least one slot 238 may be configured to accept the at least one coupling member 222 member therein such that the coupling member 222 (and thereby the first engagement member 236) is able to slide or translate along the at least one slot 238 (and thereby translate along the axis of the second one attachment member 224, or vice versa), as shown in FIGS. 23, 24, 26 and 27. The first attachment member 234 is shown transparently in FIGS. 23 and 26 to show the axial movement of the second attachment member 224 with respect to the first attachment member 234 provided by the at least one slot 238 in the second attachment member 224.

[0072] The at least one slot 238 may also allow the at least one coupling member 222 member to extend through the at least one slot 238 and into the third cavity 226. As such, the plug member 261 may include at least one aperture 265 that is configured to accept the at least one coupling member 222 member therein and substantially fixedly couple the plug member 261 and the first attachment member 234 (e.g., at least along the axial direction). As noted above, to allow the actuation member 281 to be accessed or engaged from the first open end 225 of the second engagement member 224, both the plug member 261 and the resilient member 240 may be hollow or otherwise configured to allow a tool or device to pass or extend entirely through and into the first and/or second cavity 236, 285 of the first attachment member 234.

[0073] As shown in FIG. 24, when the device, implant or system 210 is assembled and the resilient member 240 is "loaded," the device, implant or system 210 is essentially a one-piece implant that can be inserted across one or more junctions of one or more tissue or bone segments. In such an "implantation state," as shown in FIGS. 22-24, the device, implant or system 210 may be assembled such that the second engagement member 224 extends from the first cavity 236 of the second engagement member 234 with the at least one coupling member 222 passing through the at least one aperture 223 of the first engagement member 234 and the at least one slot 238 of the second engagement member 224 to slidably engage the components. As shown in the cross-sectional view of FIG. 24, in the implantation state of the device, implant or system 210 the plug member 261 may also be positioned within the third cavity 226 of the second engagement member 224 with the at least one coupling member 222 passing (through the at least one slot 238 and) at least into the at least one aperture 265 of the plug member 261 to

substantially fix the plug member 261 and the first engagement member 234, but allow the second bone engagement member 224 to axially slide or translate there between.

[0074] As also shown in FIG. 24, in the implantation state, the actuation member 281 may be positioned (e.g., threadably) within the second cavity 283 such that it extends into the first cavity 236 and abuts with the at least partially closed second end 227 of the second engagement member 224. In fact, the actuation member 281 may be positioned such that it axially translates the second

engagement member 224 out from the first cavity 236 (i.e., the at least one slot 238 translates over the at least one coupling member 222). In some such embodiments, in the implantation state the second engagement member 224 may be axially translated to its greatest extent such that the at least one coupling member 222 is positioned at the end of the at least one slot 238, as shown in FIGS. 26 and 27. In this way, in the implantation state, the device, implant or system 210 may be configured such that the resilient member 240 is compressed or "pre-loaded" between the at least partially closed second end 227 of the second engagement member 224 and the plug member 261 .

[0075] After implantation of the device, implant or system 210 in the preloaded implantation state into two or more tissue or bone segments and across one or more joint, fracture or other junction between the two or more tissue or bone segments, the actuation member 281 may be actuated to release at least some of the pre-load of the resilient member 240 to "push" the first and second engagement members 234, 224 axially together as shown in FIGS. 25-27 and, ultimately, provide a compressive force across the one or more junctions. For example, the pathway of the device, implant or system 210 through the two or more tissue or bone segments (i.e., the implantation pathway) may be utilized to access the actuation member 281 via a tool or other device (by way of either the substantially open second end 239 of the first attachment member 234 or the substantially open first end 225 of the second attachment member 224, depending upon the direction or orientation of impanation, for example).

[0076] As shown in FIGS. 25-27, actuation of the device, implant or system

210 from the pre-loaded implantation state may involve translating (e.g., threadably via rotation) the actuation member 281 at least partially out from the first cavity 236 of the first attachment member 234 (toward the second cavity 283 and the substantially open second end 239). The pre-loaded compression of the resilient member 240 may thereby be "released" and allowed to act upon the plug member 261 and the substantially closed second end 227 of the second engagement member 224. As the plug member 261 is axially fixed to the first engagement member 234 via the at least one coupling member 222, upon activation of the device, implant or system 210 the resilient member 240 acts or "pushes" against (i.e., applies a force to) the substantially closed second end 227 of the second engagement member 224 to translate the second engagement member 224 further into the first cavity 236 of the first engagement member 234, as shown in FIGS. 25- 27. During the axial translation of the second engagement member 224 into the first cavity 236 of the first engagement member 234, the at least one slot 238 may axially move over or about the at least one coupling member 222.

[0077] When the device, implant or system 210 has been implanted across one or more junctions between two or more tissue or bone segments, axial translation of the second engagement member 224 (secured to one or more of the segments) into the first engagement member 234 (secured to one or more of the other segments) reduces the junction(s) there between (if present) and applies a compression force to the junction(s) via the resilient member 240.

[0078] As described in detail above, the fusion devices, systems, implants and corresponding methods of the present disclosure are configured to apply a compression force to a junction between bone or tissue segments to promote or achieve fusion thereof. In some embodiments, the fusion devices, systems, implants and corresponding methods are configured to apply a compressive force to a bone or tissue junction within the range of about 1 Ibf to about 40 Ibf, depending upon the specific clinical application. In some such embodiments, the internal resilient member or biasing element of the devices, systems, implants and methods may be configured to provide the about 1 LBF to about 40 LBF compressive force.

[0079] As also described above, the fusion devices, systems, implants and corresponding methods of the present disclosure may be configured to reduce a gap between bone or tissue segments, and then apply a compressive force thereto. The fusion devices, systems, implants and corresponding methods achieve such reduction and compression via relative movement, for example, between first and second engagement members. In some embodiments, the fusion devices, systems, implants and corresponding methods may be configured such that the maximum travel between the first and second engagement members is within the range of about 1 mm to about 4 mm. In some embodiments, a slot of the fusion devices, systems, implants and corresponding methods may be configured to provide such about 1 mm to about 4 mm travel between the first and second engagement members.

[0080] The total length and width of the fusion devices, systems, implants and corresponding methods of the present disclosure may be designed to suit a particular patient and/or a particular specific clinical application. In some

embodiments, the fusion devices, systems, implants and corresponding methods may define a maximum total length within the range of about 20 mm to about 180 mm and/or a maximum total width (e.g., diameter) within the range of about 3 mm to about 8 mm.

[0081] The embodiments described herein may also be used to stabilize broken or fragmented bones having fragments. The embodiments described herein may also be used to fuse bone joints, typically after bone joint failure, when the bone joints have been stripped of articular cartilage.

[0082] While the embodiments described herein each embody different characteristics, it is understood to one of ordinary skill in the art that features of all embodiments described herein with respect to each of the individual Figures may be combined with features described with respect to other Figures of the present disclosure. Furthermore, any of the embodiments described herein are not meant to be limiting and any combination of features of the embodiments described herein that could or would be implemented by one of ordinary skill in the art should be recognized [0083] The foregoing Detailed Description is understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the

embodiments disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the disclosure. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the disclosure.

Claims

WE CLAIM:

1 . A bone or tissue compression device, comprising:

a first attachment member configured to couple within a first bone or tissue segment and including a first cavity, first and second ends, and at least one first aperture extending into the first cavity between the first and second ends;

a second attachment member configured to couple within a second bone or tissue segment and including a second cavity, a substantially closed first end, a second end, and at least one slot extending into the second cavity between the first and second ends, wherein the second attachment member is positioned partially within the first cavity of the first attachment member and extends through the second end thereof;

a plug member including first and second ends and at least one second aperture between the first and second ends, wherein the plug member is positioned within the second cavity of the second attachment member and at least partially within the first cavity of the first attachment member;

a resilient member, in a compressed state, positioned within the second cavity of the second attachment member between the substantially closed first end of the second attachment member and the first end of the plug member;

an actuation member translatably coupled within the first cavity of the first attachment member; and

at least one coupling member extending into the at least one first aperture of the first attachment member, the at least one slot of the second attachment member, and the at least one second aperture of the plug member.

2. The compression device of claim 1 , wherein the actuation member is translatable between a first position with the coupling member being distal to the first end of the first attachment member and engaged with the first end of the second attachment member, and a second a second position with the actuation member being proximate to the first end of the first attachment member and spaced from the first end of the second attachment member.

3. The compression device of claim 1 , wherein the actuation member is engageable via a tool extending through the first end of the first attachment member or the second end of the second attachment member and within the first cavity of the first attachment member.

4. The compression device of claim 1 , wherein the actuation member is threadably engaged within the first cavity of the first attachment member.

5. The compression device of claim 1 , wherein the first end of the first attachment member includes an expanded head portion.

6. The compression device of claim 5, wherein an outer surface of the portion of the first attachment member extending between the second end and the expanded head portion is substantially smooth.

7. The compression device of claim 6, wherein an outer surface of the second attachment member includes threads.

8. The compression device of claim 1 , wherein the at least one coupling member is at least one pin.

9. The compression device of claim 1 , wherein the actuation member abuts a first side of the substantially closed first end of the second attachment member and the resilient member abuts a second opposing side of the substantially closed first end of the second attachment member.

10. The compression device of claim 9, wherein the position of the actuation member within the first cavity of the first attachment member dictates the relative positioning of the first and second attachment members with respect to each other.

1 1 . A method of applying a compressive force to a junction between a first bone or tissue segment and second bone or tissue segment, comprising:

positioned the bone or tissue compression device of claim 1 within the first and second bone or tissue segments and across the junction.

12. The method of claim 1 1 , further including translating the actuation member within the first cavity of the first attachment member such that the bone or tissue compression device applies a compressive force to the junction.

13. A bone or tissue fusion device, comprising:

a first assembly comprising:

a latch with at least one deflectable arm and a pawl provided thereon;

a resilient member in a first compressed state;

a retainer positioned between the latch and the resilient member; and a first attachment member configured to couple within a first bone segment and including a first cavity and at least a one slot extending into the first cavity, wherein the latch, retainer and resilient member are slidably coupled within the first cavity, and the pawl is positioned within the at least a one slot, and

a second assembly comprising:

a second attachment member configured to couple within a second bone segment and including a second cavity, and

a pin extending into the second cavity,

wherein the first assembly is slidably received within the second cavity of the second assembly such that the pawl of the first assembly engages the pin of the second assembly, and

wherein the device is configured to be activated such that the resilient member expands from the first compressed state to a second less compressed working state to force the latch toward the first bone segment and thereby pull the second assembly toward the first assembly.

14. The bone or tissue fusion device of claim 1 , comprising activating the device by at least partially removing a member fixing the retainer and the first attachment member from the first assembly.