Methods and devices for sacroiliac joint fusion

Abstract

A surgical fixation assembly and associated method for fusing a sacroiliac joint are described herein. The surgical fixation assembly includes a compression member, a stabilizer, and a locking element. The compression member is rotatably implantable within two bone segments separated by a joint. The stabilizer is configured to couple with the compression member in situ after implantation of the compression member and prevent rotation of the compression member after implantation. The locking element is provided on the stabilizer and is movable from a first position that allows coupling of the stabilizer with the compression member to a second position that prevents disengagement of the stabilizer from the compression member.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application is an international application claiming the benefit of priority from commonly owned, co-pending U.S. Provisional Application No. 63 / 485,795, entitled "SPINAL FIXATION SYSTEM FOR THE SI-JOINT," filed February 17, 2023, the entire contents of which are incorporated by reference into this disclosure as if fully set forth herein.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to orthopedic surgery, and more particularly to artificial joints (implants) and methods of sacroiliac joint fusion. [Background technology]

[0003] The sacroiliac joint ("SI joint") is the joint between the sacrum (the triangular bone at the base of the spine) and the ilium (the broad, flat bone that forms the top of the hipbone). The sacroiliac joint is a synovial joint cavity filled with synovial fluid and supported by ligaments and muscles. The sacroiliac joint has a sacral component formed by the auricular surfaces of the sacrum, which are ear-like surfaces on either side of the sacrum that articulate with the ilium. The sacral component of the joint is relatively immobile. The iliac component of the joint is formed by the iliac surface of the ilium, which articulates with the sacrum. Between the sacral and iliac components of the sacroiliac joint is a layer of fibrocartilage called the interosseous ligament. This ligament connects the two bones and helps stabilize the joint. The joint is also supported by several other ligaments and muscles, including the sacroiliac ligament, iliolumbar ligament, and gluteus maximus.

[0004] Sacroiliac joint dysfunction is a condition that occurs when there is abnormal movement or alignment of the sacroiliac joint, which is the joint that connects the sacrum (the triangular bone at the base of the spine) to the pelvis. This can cause pain in the lower back, buttocks, and legs, as well as stiffness and difficulty moving.

[0005] Sacroiliac joint fusion is a surgical procedure aimed at permanently joining the sacrum and ilium of the pelvis at the sacroiliac joint. Sacroiliac joint fusion is typically performed to treat chronic sacroiliac joint pain, which can result from a variety of conditions, such as degenerative joint disease, trauma, or pregnancy. The procedure involves removing damaged joint surfaces and replacing them with bone grafts or other materials that promote new bone growth across the joint.

[0006] One treatment option for sacroiliac joint dysfunction is an implant system. This typically involves inserting a small implant into the joint to stabilize the joint and reduce the abnormal movement that causes pain and discomfort. The specific type of implant system used depends on the severity of the dysfunction and the needs of the individual patient. Examples of implant systems that may be used include:

[0007] SI Joint Fusion System: This type of implant system involves fusing the sacrum and ilium (the largest bones in the pelvis) using screws and / or plates. This helps stabilize the joint and prevent abnormal movement. Over time, the bones grow together, forming a permanent fusion.

[0008] SI joint fusion system: This type of implant system involves the use of screws or rods to stabilize the joint without fusing the bones together. This allows some movement in the joint but can still help reduce pain and discomfort.

[0009] SI Joint Distraction System: This type of implant system involves the use of a small, minimally invasive implant to generate a distraction force across the joint. This reduces the force on the joint and helps relieve pain.

[0010] In each of these instances, surgical hardware must be placed at multiple spinal levels to achieve a stable fixation or fusion construct, requiring more time in the operating room, more exposure under fluoroscopy, more hardware, increased costs, and increased need for revisions.

[0011] There is a need to improve upon current fixation and fusion systems and techniques for attachment. Summary of the Invention

[0012] In some embodiments, the present disclosure describes improved implants and surgical techniques for providing spinal segment fixation and stabilization in skeletally mature patients in the treatment of acute and chronic instability or deformity, including degenerative disc disease such as spondylolisthesis, injuries such as fractures, spinal stenosis, sacroiliac joint fusion, and failure of previous fusions. Sacroiliac joint fusion, including sacroiliac joint dysfunction, is a direct result of sacroiliac joint disruption and degenerative sacroiliitis. In some embodiments, the implant assembly described herein, by way of example, allows for direct bone grafting only by providing a lattice topology and fenestrations. In some embodiments, the assembly includes anti-rotational stabilization, allowing for complete fixation of the sacrum using a single-level procedure. In some embodiments, the assembly provides a modular, all-in-one system that can be powered.

[0013] In some embodiments, the surgical fixation assemblies of the present disclosure provide improved fixation with several important factors, including anti-rotation and stabilization. By way of example, anti-rotation is an important feature because rotation of an implanted rotatable (e.g., threaded) device can be problematic until the device is integrated into the bone (e.g., typically three months). By way of example, stabilization is an important feature because the larger surface area and geometry of the two implants (e.g., compression member and stabilizer) coming together through the joint will be more stable, especially compared to a threaded cage that tapers into the sacrum with a smaller diameter.

[0014] In some embodiments, the present disclosure provides a placement method with reduced steps. In some embodiments, all placement options can be facilitated with power as needed. In some embodiments, the placement method may provide a user utilizing robotics, surgical navigation, and / or virtual reality with the ability to know the implant's length prior to placement and place it with power in one step. In some embodiments, the placement method may include reverse drilling (e.g., for guide pin stabilization), which includes a reverse drill tip on the guide pin to increase the guide pin's diameter and address guide pin impaction during implant placement; the reverse drill tip will only cut and move forward when rotated counterclockwise or against the lead of the implant thread. The implant is preferably inserted while rotating in a clockwise direction, and the guide pin is stationary to reduce steps and fluoroscopy shots. Thus, the guide pin can be retracted at the same or similar rate as the implant is inserted.

[0015] In some embodiments, the presently disclosed surgical fixation assemblies include implants made from any suitable biocompatible material, including (by way of example only) but not limited to titanium, polymer, PEEK, bone, etc. In some embodiments, the presently disclosed surgical fixation assemblies use trajectory guides to allow screws or bolts to pass through the SI joint at a predetermined angle. In some embodiments, the presently disclosed surgical fixation assemblies include radiographic markers to assist the user in visualizing the placement of the assembly before, during, and / or after implantation. In some embodiments, the presently disclosed surgical fixation assemblies can be configured for use with navigation, robotics, and / or virtual reality systems. In some embodiments, the presently disclosed surgical fixation assemblies can be used with inserters that allow implants to be placed into the SI space from a lateral trajectory, a postero-lateral trajectory, and a postero-medial trajectory.

[0016] In some embodiments, the presently disclosed surgical fixation assemblies can be used in a variety of surgical procedures at various locations throughout the body. In some embodiments, the surgical fixation assemblies disclosed herein can be optimized for use in sacroiliac joint fusion procedures in the spine of a human patient. By way of example, the surgical fixation assembly includes a compression member and a stabilizer configured to be coupled to the compression member in situ (e.g., after the compression member is implanted at a surgical target site) and secured in place with a locking element.

[0017] In some embodiments, the compression member may comprise any device configured to engage two separate bone portions to hold them in position relative to one another. In some embodiments, the compression member may comprise a bone anchor having a cylindrical elongate shaft with a proximal end, a distal end, and a central portion positioned between the proximal and distal ends. In some embodiments, the compression member may further comprise one or more helical threads disposed about the outer surface of the elongate shaft. In some embodiments, the helical threads may have multiple pitch zones configured to obtain bite into different types of bone, for example, cortical bite zones at the proximal and distal ends and a cancellous pitch zone in the central portion. As an example, in a sacroiliac joint fusion procedure, the compression member may be positioned so that the distal end is engaged with the sacrum, the proximal end is engaged with the ilium, and the middle portion spans the sacroiliac joint.

[0018] In some embodiments, the compression member further includes a central lumen extending longitudinally therethrough between the proximal and distal ends. By way of example only, the central lumen may have a generally cylindrical cross-section and be configured to allow one or more surgical instruments or accessories, including, but not limited to, a guidewire and / or a drill bit, to pass through the compression member.

[0019] In some embodiments, the compression member includes one or more coupling mechanisms configured to receive at least a portion of the stabilizer to couple the stabilizer to the compression member, hi some embodiments, the compression member includes a capture mechanism to engage the locking element to prevent the stabilizer from disengaging from the compression element.

[0020] In some embodiments, the stabilizer comprises any device or element configured to couple with the compression member in situ to prevent rotation and / or other movement of the compression member while implanted in bone. In some embodiments, the stabilizer acts as a coupleable flange associated with the compression member after it is implanted in bone, preventing rotation of the compression member by providing a physical barrier with an extended surface area that abuts the bone to prevent rotation. In some embodiments, the stabilizer may comprise a secondary fastener that extends into the bone through a coupler associated with the compression element.

[0021] In some embodiments, the elongate body may have a cross-section having a triangular shape. In some embodiments, the triangular shape may be oriented such that the apex of the triangle is directed laterally away from the compression member when the stabilizer is coupled to the compression member. By way of example, the elongate body may have any cross-sectional shape capable of providing sufficient surface area for engaging bone. In some embodiments, the stabilizer may have a tapered distal end to facilitate more efficient insertion into bone with minimal disruption. In some embodiments, the stabilizer may have one or more lateral openings configured to allow bone growth through the stabilizer to further secure the positioning of the fusion assembly over time.

[0022] By way of example only, the stabilizer bar includes a coupling mechanism configured to engage with the coupling mechanism of the compression element to enable secure and guided coupling of the stabilizer bar to the compression element.

[0023] In some embodiments, the stabilizer includes a proximal coupler sized and shaped to mate with a proximal recess in the compression member. In some embodiments, the proximal coupler may include a locking mechanism configured to move between a first unlocked position that allows slidable movement of the stabilizer relative to the compression member in a proximal (e.g., during insertion) and / or distal (e.g., during removal) direction, and a second locked position that prevents movement of the stabilizer relative to the compression member.

[0024] In some embodiments, the locking mechanism may include a locking element in the form of a C-clip coupled to the stabilizer within a circumferential groove formed in the proximal coupler. In some embodiments, the locking element may include one or more lateral flanges configured to be received within the radial grooves of the compression member when the locking element is rotated from the unlocked position to the locked position. In some embodiments, the one or more lateral flanges may further include surface markings that provide a visual indication of the orientation and status of the locking element.

[0025] In some embodiments, the proximal coupler further includes a threaded opening configured to receive a portion of the inserter therein.

[0026] In some embodiments, the present disclosure describes a method for performing an orthopedic fusion procedure, such as a sacroiliac joint fixation in the human spine. In some embodiments, the first step of the method is to establish a surgical pathway to a surgical target site, which in this exemplary embodiment is the joint between the ilium and sacrum of a human patient. By way of example only, the fusion procedure may be performed at any level of the sacrum, including, but not limited to, one or more of the S1, S2, and S3 spinal levels. Notably, implantation of a surgical fixation assembly may achieve sacroiliac fusion using an implant at only one level, although the procedure may be repeated at multiple levels if the surgeon desires. In any event, the surgical pathway may be established by methods commonly known in the surgical arts, including open and / or minimally invasive techniques, along with various substeps, including (but not limited to) (a) determining an access trajectory to the surgical target site (e.g., using robotics or other methods), (b) creating an opening in the patient's skin along the determined access trajectory, (c) dilating the soft tissue between the patient's skin and the surgical target site, and (d) retracting the soft tissue to maintain the surgical pathway and provide the surgeon with better visibility through the dilated opening. In some embodiments, any of substeps (a)-(d) may be performed manually or robotically.

[0027] In some embodiments, the second step of the method is to determine the size (e.g., length and / or diameter) of the compression member to be used in the procedure. In some embodiments, this step may be accomplished using a depth gauge. In some embodiments, this step may be accomplished using robotics.

[0028] In some embodiments, the third step of the method is to secure the compression member to the driver instrument with the drill bit of the driver instrument extending through the central lumen of the compression member and extending distally beyond the distal end of the compression member.

[0029] In some embodiments, the fourth step of the method is inserting a compression member through a first bone segment (e.g., the patient's ilium) and into a second bone segment (e.g., the patient's sacrum) so that the proximal end of the compression member is seated in the ilium, the distal end of the compression member is seated in the sacrum, and a central portion of the compression member extends across the sacroiliac joint. By way of example, the compression member may be inserted at any one of sacral levels S1, S2, or S3 to achieve sacroiliac joint fixation, or at multiple levels if so desired. In some embodiments, the drill bit rotates faster (e.g., twice as fast) than the compression member. In some embodiments, the drill bit and compression member rotate in opposite directions (e.g., the drill bit rotates clockwise while the compression member rotates counterclockwise, or the drill bit rotates counterclockwise while the compression member rotates clockwise). In some embodiments, insertion may continue until the drill bit perforates the sacral cortex.

[0030] In some embodiments, the fifth step of the method is removing the driver instrument once the compression member is seated in the desired position as described above. By way of example, removing the driver instrument may include the substeps of separating the driver instrument from the compression member and withdrawing the driver instrument from the surgical channel.

[0031] In some embodiments, a sixth step of the method includes coupling a stabilizer to the compression member after the compression member has been implanted. In some embodiments, this step of the method may be accomplished by first coupling the stabilizer to an insertion instrument. The stabilizer is then advanced through the surgical channel and coupled to the compression member. As the stabilizer is advanced along the compression member during coupling, the elongated body displaces bone material to either side, which in turn applies force back to the elongated body, holding the stabilizer in place and thereby preventing rotation of the compression member.

[0032] It should be noted that, in practice, the compression member may occasionally be inserted into the patient in a slightly off-target position. Rather than removing and reinserting the compression member, this may be addressed by selectively positioning a stabilizer bar to extend laterally from the compression member, preferably to overcome the misaligned implant and achieve a solid union without revision. The orientation of the stabilizer bar may be changed by rotating the compression member to orient the elongated track in the desired direction of extension of the stabilizer bar prior to inserting the stabilizer bar.

[0033] In some embodiments, the seventh step of the method is engaging a locking element to prevent retraction or separation of the stabilizer from the compression member. For example, once the stabilizer is fully coupled to the compression element, the locking element may be engaged to secure the coupling of the compression element and the stabilizer. To accomplish this, the locking element may be rotated so that one or more lateral flanges are moved from an initial unlocked position, in which the lateral flanges are aligned with the elongated body and not positioned under one or more overhangs of the compression member, to a locked position, in which the lateral flanges are positioned under the overhangs and within the radial grooves. When the lateral flanges are in this second, locked position, the overhangs prevent separation of the stabilizer from the compression member. At this point, the surgical fixation assembly is fully implanted and locked.

[0034] In some embodiments, the eighth step of the method includes removing any remaining instrumentation from the surgical channel and closing the incision.

[0035] In some embodiments, the method may include a first step (or previous step) of inserting an implant member into the sacroiliac joint, for example, using a posterior insertion method. In some embodiments, the implant (graft) may have holes that help determine the trajectory of the incoming implant, similar to, for example, a femoral nail. The substep of determining the access trajectory would then be modified to align the access trajectory with at least one of the holes in the graft. The procedure then proceeds as described herein.

[0036] In some embodiments, compression members may be provided in a variety of shapes and sizes. While the overall size of the compression members may vary, most features (e.g., stabilizer engagement features, inserter engagement features, etc.) of different sized compression members are the same size to ensure that the same (or identical) stabilizers can be used with any sized compression member; this preferably reduces costs, increases efficiency, and reduces potential errors associated with providing users with kits containing various sized compression members with stabilizers that can be used with any of the compression members.

[0037] In some embodiments, the compression member includes a coupling element configured to receive at least a portion of the stabilizer to couple the stabilizer to the compression member. In some embodiments, the coupling element may comprise a cap or washer coupled to a proximal end of the compression member and having at least one lateral flange with an opening configured to receive at least a portion of the stabilizer therethrough to capture and hold the stabilizer in a desired angular orientation relative to the compression member during in situ assembly.

[0038] In some embodiments, the stabilizer comprises a secondary anchor that may be threadably engaged with the aperture, hi some embodiments, the stabilizer comprises a secondary anchor that passes through the aperture but is not threadably engaged with the aperture.

[0039] In some embodiments, the compression member includes a coupling mechanism configured to receive at least a portion of the stabilizer to couple the stabilizer to the compression member. In some embodiments, the coupling mechanism comprises a guide post having an elongated shaft configured to extend through the central lumen and a proximal circumferential recess configured to receive at least a portion of the proximal coupler of the stabilizer therein. By way of example, the elongated shaft may have a threaded distal end to enable secure coupling with the stabilizer. In some embodiments, the guide post may be configured to engage two or more stabilizers.

[0040] In some embodiments, the surgical fixation assembly can be used with an alignment bracket that provides an insertion tool for the interbody spacer, as well as a rigid arm that is positioned along the inserter shaft before or during the procedure to reduce steps, enable a low-cost alternative to robotics, or enable VR and navigation as a trajectory guide. Multiple drill guide options can be provided on the arm. In some embodiments, the rigid arm includes a proximal end that includes one or more through-holes aligned with the interbody spacer for instrumentation on a determined insertion trajectory.

[0041] In addition to the embodiments described below, the present disclosure describes the following embodiments.

[0042] Embodiment 1 is a surgical fixation assembly comprising: a compression member having a cylindrical body having a proximal end, a distal end, an intermediate portion extending longitudinally between the proximal and distal ends, a first bone engagement feature positioned at the proximal end, a second bone engagement feature positioned at the distal end, and a stabilizer engagement feature positioned on an outer surface of the compression member; an independent stabilizer configured to couple to the compression member by interacting with the stabilizer engagement features, the independent stabilizer having an elongated body having a third bone engagement feature and an engagement feature; and a locking element rotatably coupled to the stabilizer, the locking element configured to move between a first position that allows movement of the stabilizer relative to the compression member before or during coupling of the stabilizer and the compression member, and a second position that prevents movement of the stabilizer relative to the compression member after coupling of the stabilizer and the compression member.

[0043] Embodiment 2 is the assembly of embodiment 1, wherein the first bone-engaging feature comprises a helical thread disposed around the outer surface of the cylindrical body at the proximal end.

[0044] Embodiment 3 is the assembly of embodiment 1 or 2, wherein the second bone-engaging feature comprises a helical thread disposed around the outer surface of the cylindrical body at the distal end.

[0045] Embodiment 4 is an assembly described in any of embodiments 1-3, wherein the stabilizer engagement feature comprises a longitudinal recess formed in the outer surface of the cylindrical body and extending between the proximal end and the distal end.

[0046] Embodiment 5 is the assembly of any of embodiments 1-4, wherein the longitudinal recess is configured to slidably receive at least a portion of the stabilizer therein.

[0047] Embodiment 6 is an assembly described in any of embodiments 1-5, wherein the compression member has an inner lumen extending longitudinally through the elongate body between the opening at the first end and the opening at the second end.

[0048] Embodiment 7 is the assembly of any of embodiments 1-6, wherein the compression member includes at least one lateral opening formed in the elongate body.

[0049] Embodiment 8 is the assembly of any of embodiments 1-7, wherein the stabilizer has a triangular cross-sectional shape.

[0050] Embodiment 9 is the assembly of any of embodiments 1-8, wherein the stabilizer has at least one transverse opening formed therein.

[0051] Embodiment 10 is the assembly of any of embodiments 1-9, wherein the locking element has at least one lateral flange configured to engage with the compression member when the locking element is in the second position.

[0052] Embodiment 11 is a method of fusing a first bone segment and a second bone segment across a joint between the first and second bone segments, the method comprising the steps of: establishing a surgical pathway to a surgical target site; securing a compression member to a driver instrument having an elongated drill bit at a distal end, the compression member comprising a cylindrical body having a proximal end, a distal end, an intermediate portion extending longitudinally between the proximal and distal ends, a first bone-engaging feature positioned at the proximal end, a second bone-engaging feature positioned at the distal end, a stabilizer engagement feature positioned on an outer surface of the compression member, and an inner lumen extending longitudinally through the elongated body between an opening at the first end and an opening at the second end; and engaging the second bone-engaging feature with the first bone-engaging feature so that the second bone-engaging feature is seated within the second bone segment and the first bone-engaging feature engages the first bone segment. implanting a compression member at a surgical target site by rotatably advancing the compression member through a first bone segment, across the joint, and into a second bone segment until the compression member is seated within the first bone segment and an intermediate portion extends across the joint; advancing an independent stabilizer through the surgical channel toward the implanted compression member; in situ coupling the independent stabilizer to the implanted compression member to prevent rotation of the implanted compression member relative to the first and second bone segments; and rotating a locking element coupled to the stabilizer from a first position that allows movement of the stabilizer relative to the compression member to a second position that prevents movement of the stabilizer relative to the compression member upon in situ coupling of the stabilizer and compression member.

[0053] Embodiment 12 is a method according to embodiment 11, wherein the compression member is secured to the driver instrument such that the distal tip portion of the elongated drill bit extends through the inner lumen of the compression member and protrudes distally from the distal end of the compression member.

[0054] Embodiment 13 is a method according to embodiment 11 or 12, wherein the step of embedding the compression member within the surgical target site includes the substeps of advancing a driver instrument having a fixed compression member distally through the surgical pathway until a distal tip portion of the drill bit contacts the first bone segment, and operating the driver instrument to rotate the drill bit and compression member.

[0055] Embodiment 14 is a method according to any one of embodiments 11-13, wherein the driver instrument is detached from the compression member and removed from the surgical channel before performing the step of installing the stabilizer.

[0056] Embodiment 15 is a method according to any of embodiments 11-14, wherein the first bone-engaging feature comprises a helical thread disposed around the outer surface of the cylindrical body at the proximal end.

[0057] Embodiment 16 is a method according to any of embodiments 11-15, wherein the second bone-engaging feature comprises a helical thread disposed around the outer surface of the cylindrical body at the distal end.

[0058] Embodiment 17 is a method according to any of embodiments 11-16, in which the step of connecting an independent stabilizer to an embedded compression member in situ includes the substeps of positioning a portion of a connecting element provided on the stabilizer within a portion of a stabilizer engagement feature of the compression member, and advancing the stabilizer distally along the compression member by slidably translating the connecting element within the stabilizer engagement feature.

[0059] Embodiment 18 is the method of any of embodiments 11-17, wherein the coupling element comprises an elongated guide rail and the stabilizer engagement feature comprises an elongated track.

[0060] Embodiment 19 is the method of any of embodiments 11-18, wherein the elongated guide rail is secured within the elongated track using a dovetail mechanism.

[0061] Embodiment 20 is a method according to any of embodiments 11-19, wherein the locking element has at least one lateral flange configured to engage with the compression member when the locking element is in the second position.

[0062] Other objects and advantages of the present disclosure will become apparent from the following description taken in conjunction with any accompanying drawings, in which certain embodiments of the present disclosure are set forth, by way of illustration and example. Any drawings contained herein constitute a part of this specification and include illustrative embodiments of the present disclosure and illustrate various objects and features thereof. [Brief explanation of the drawings]

[0063] The many advantages of the present disclosure will become apparent to those skilled in the art upon reading this specification in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a perspective view of an example of an assembled surgical fixation assembly configured for sacroiliac joint fusion, according to some embodiments. [Figure 2] FIG. 2 is another perspective view of the surgical fastening assembly of FIG. 1 in accordance with some embodiments. [Figure 3] FIG. 2 is a front plan view of the surgical fastening assembly of FIG. 1 in accordance with some embodiments. [Figure 4] FIG. 2 is a side view of the surgical fastening assembly of FIG. 1 in accordance with some embodiments. [Figure 5] FIG. 2 is an exploded perspective view of the surgical fastening assembly of FIG. 1 in accordance with some embodiments. [Figure 6] 2 is a perspective view of an example of a compression member forming part of the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 7] FIG. 7 is a front plan view of the compression member of FIG. 6 according to some embodiments. [Figure 8] FIG. 7 is a side view of the compression member of FIG. 6, according to some embodiments. [Figure 9] 9 is a side view of the compression member of FIG. 6 rotated 90 degrees from the view of FIG. 8, according to some embodiments. [Figure 10] 7 is another perspective view of the compression member of FIG. 6 according to some embodiments. [Figure 11] FIG. 7 is a top view of the compression member of FIG. 6, according to some embodiments. [Figure 12] 2 is an exploded top perspective view of an example of a stabilizer and locking element forming part of the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 13] FIG. 13 is an exploded bottom perspective view of the stabilizer and locking element of FIG. 12 according to some embodiments. [Figure 14] FIG. 13 is a side view of the stabilizer and locking element of FIG. 12 coupled together, according to some embodiments. [Figure 15] FIG. 13 is a front plan view of the stabilizer and locking element of FIG. 12 coupled together, according to some embodiments. [Figure 16] FIG. 13 is a top view of the stabilizer and locking element of FIG. 12 coupled together, according to some embodiments. [Figure 17] 2A-2D are perspective views of the surgical fastening assembly of FIG. 1 in various successive stages of assembly, according to some embodiments. [Figure 18] 2A-2D are perspective views of the surgical fastening assembly of FIG. 1 in various successive stages of assembly, according to some embodiments. [Figure 19] 2A-2D are perspective views of the surgical fastening assembly of FIG. 1 in various successive stages of assembly, according to some embodiments. [Figure 20] 2 is a top view of the assembled surgical fastening assembly of FIG. 1 with the locking elements in an unlocked position, according to some embodiments. [Figure 21] 2 is a top view of the assembled surgical fastening assembly of FIG. 1 with the locking element in a locked position, according to some embodiments. [Figure 22] 10 is a flowchart depicting several steps of a method of performing a sacroiliac joint fusion procedure using the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 23]FIG. 2 is a perspective view of an example of a robotic platform configured for use with the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 24] 2 is a side view of an inserter coupled to a compression member forming part of the surgical fastening assembly of FIG. 1, according to some embodiments. [Figure 25] 2 is a perspective view of the surgical fixation assembly of FIG. 1 during implantation in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 26] 2 is a perspective view of the surgical fixation assembly of FIG. 1 during implantation in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 27] 2 is a perspective view of the surgical fixation assembly of FIG. 1 during implantation in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 28] 2 is a plan view of a perspective image of the surgical fixation assembly of FIG. 1 after implantation in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 29] 2A-2C are front, perspective, top, and perspective views, respectively, of another example of a compression member forming part of the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 30] 2A-2C are front, perspective, top, and perspective views, respectively, of another example of a compression member forming part of the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 31] 2A-2C are front, perspective, top, and perspective views, respectively, of another example of a compression member forming part of the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 32] 2A-2C are front, perspective, top, and perspective views, respectively, of another example of a compression member forming part of the surgical fixation assembly of FIG. 1, according to some embodiments. [Figure 33] FIG. 10 is a perspective view of another example of a surgical fixation assembly configured for use in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 34]FIG. 10 is a perspective view of another example of a surgical fixation assembly configured for use in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 35] FIG. 10 is a perspective view of another example of a surgical fixation assembly configured for use in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 36] FIG. 10 is a perspective view of another example of a surgical fixation assembly configured for use in a sacroiliac joint fusion procedure, according to some embodiments. [Figure 37] 2 is a perspective view of an inserter and alignment fixture configured to cooperate with the surgical fastener assembly of FIG. 1, according to some embodiments. [Figure 38] FIG. 38 is a side view of the inserter and alignment bracket of FIG. 37, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0064] Exemplary embodiments of the present disclosure are described below. For clarity, not all features of an actual implementation are described herein. It will, of course, be understood that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's particular goals, including compliance with system- and business-related constraints that vary from implementation to implementation. It will further be understood that such a development effort may be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The surgical fixation assemblies and related methods disclosed herein possess a variety of inventive features and components, both individually and in combination, that warrant patent protection.

[0065] 1-5 illustrate an example of a surgical fixation assembly 10 according to some embodiments of the present disclosure. By way of example, the surgical fixation assembly 10 may be used in a variety of surgical procedures at various locations throughout the body. In some embodiments, the surgical fixation assembly 10 disclosed herein may be optimized for use in sacroiliac joint fusion surgery in the spine of a human patient. By way of example, the surgical fixation assembly 10 includes a compression member 12 and a stabilizer 14 configured to be coupled to the compression member 12 in situ (e.g., after the compression member 12 is implanted in a surgical target site) and secured in place using a locking element 16.

[0066] 6-11 , compression member 12 may comprise any device configured to engage two separate bone portions to hold them in place relative to one another. In some embodiments, compression member 12 may comprise a bone anchor having a cylindrical elongated shaft 18 having a proximal end 20, a distal end 22, and a central portion 24 positioned between proximal end 20 and distal end 22. In some embodiments, compression member 12 may further comprise one or more helical threads 26 disposed about the outer surface of elongated shaft 18. In some embodiments, helical thread 26 may have multiple pitch zones configured to obtain bite into different types of bone, e.g., cortical bite zones at proximal end 20 and distal end 22, and a cancellous pitch zone at central portion 24. By way of example, in a sacroiliac joint fusion procedure, compression member 12 may be positioned such that distal end 22 engages sacrum 5 and proximal end 24 engages ilium 7 (see, e.g., FIG. 23 ).

[0067] In some embodiments, compression member 12 further includes a central lumen 28 extending longitudinally therethrough between proximal end 20 and distal end 22. By way of example only, the central lumen may have a generally cylindrical cross-section and be configured to allow one or more surgical instruments or accessories, including, but not limited to, a guidewire and / or a drill bit, to pass through the compression member.

[0068] In some embodiments, the compression member 12 includes a coupling mechanism configured to receive at least a portion of the stabilizer 14 to couple the stabilizer 14 to the compression member 12. For example, the compression member 12 of the exemplary embodiment includes a coupling mechanism including a recess 30 formed in the proximal end 20 and configured to receive at least a portion of the proximal coupler 44 of the stabilizer 14 therein, and an elongated track 32 extending longitudinally along the outer surface of the elongated shaft 18 and configured to receive the guide rail 48 of the stabilizer 14 therein during assembly. By way of example, the elongated track 32 may be configured to interrupt the helical thread 26 to enable secure coupling with the stabilizer 14. In some embodiments, the elongated track 32 may have a tapered sidewall 34 for engaging the guide rail 48 in a dovetail connection.

[0069] In some embodiments, the proximal recess 30 may include one or more ridges 36 vertically spaced from the proximal recess 30, the ridges 36 forming one or more radial grooves 38 between the ridges 36 and the proximal recess 30, the radial grooves 38 configured to receive one or more lateral flanges 56 of the locking element 16 therein to prevent separation of the stabilizer 14 from the compression element 12.

[0070] In some embodiments, the elongate shaft 18 may further include one or more side openings 40 configured to allow bone fusion through the compression member 12. In some embodiments, the central lumen 28 may be filled with a bone growth promoting material after implantation. In some embodiments, the elongate shaft 18 may include multiple openings 40 that form a bone growth promoting lattice.

[0071] 12-16, in some embodiments, stabilizer 14 comprises any device or element configured to couple with compression member 12 in situ to prevent rotation and / or other movement of compression member 12 while implanted in bone. In some embodiments, stabilizer 14 functions as a coupleable flange associated with compression member 12 after compression member 12 is implanted in bone, preventing rotation of compression member 12 by providing a physical barrier with an extended surface area that abuts the bone to prevent rotation. In some embodiments, stabilizer may comprise a secondary fastener that extends into the bone through a coupler associated with the compression element (see, e.g., FIGS. 33-34).

[0072] In this exemplary embodiment, the stabilizer 14 comprises an elongate body 42 and a proximal coupler 44. In some embodiments, the elongate body 42 may have a shaped cross-section. In some embodiments, the elongate body 42 may have a cross-section having a triangular shape. In some embodiments, the triangular shape may be oriented such that the apex of the triangle is oriented laterally away from the compression member 12 when the stabilizer 14 is coupled to the compression member 12. By way of example, the elongate body 42 may have any cross-sectional shape capable of providing sufficient surface area for engaging bone. In some embodiments, the stabilizer 14 may have a tapered distal end 52 that facilitates more efficient insertion into bone with minimal disruption. In some embodiments, the stabilizer may have one or more lateral openings 46 configured to allow bone growth through the stabilizer to further secure the positioning of the fusion assembly 10 over time.

[0073] By way of example only, the stabilizer 14 of the present embodiment includes a guide rail 48 configured to slidably engage the elongated track 32 of the compression element 12 described above to enable secure and guided coupling of the stabilizer 14 to the compression element 12 (e.g., as shown in FIGS. 17-19 ). In some embodiments, the guide rail 48 can have tapered sides 50 having a size and taper angle complementary to the tapered sidewalls 34 of the elongated track 32 to form a dovetail engagement between the stabilizer 14 and the compression element 12.

[0074] In some embodiments, the proximal coupler 44 is sized and shaped to mate with the proximal recess 30 of the compression member 12. By way of example, the proximal coupler 44 in this embodiment has a cylindrical shape, although other shapes are possible. In some embodiments, the proximal coupler 44 can include a locking mechanism configured to move between a first, unlocked position that allows slidable movement of the stabilizer 14 relative to the compression member 12 in a proximal (e.g., during insertion) and / or distal (e.g., during removal) direction, and a second, locked position that prevents movement of the stabilizer 14 relative to the compression member 12.

[0075] In some embodiments, the locking mechanism may include a locking element 16 in the form of a C-clip that is coupled to the stabilizer 14 within a circumferential groove 54 formed in the proximal coupler 44. In some embodiments, the locking element 16 may include one or more lateral flanges 56 configured to be received within the radial groove 38 of the compression member 12 when the locking element 16 is rotated from the unlocked position to the locked position. In some embodiments, one or more of the lateral flanges 56 may further include surface markings 58 that provide a visual indication of the orientation and status of the locking element 16.

[0076] In some embodiments, the proximal coupler 44 further includes a threaded opening 60 configured to receive a portion of the inserter therein.

[0077] 20-21 , once the stabilizer 14 is fully coupled with the compression element 12, the locking element 16 can be engaged to secure the coupling between the compression element 12 and the stabilizer 14. To accomplish this, the locking element 16 can be rotated so that one or more lateral flanges 56 are moved from an initial unlocked position (see, e.g., FIG. 20 ), in which the lateral flanges 56 are aligned with the elongated body 42 and not positioned beneath one or more ledges 36, to a locked position (see, e.g., FIG. 21 ), in which the lateral flanges 56 are positioned beneath the ledges 36 and within the radial grooves 38. When the lateral flanges 56 are in this second, locked position, the ledges 36 prevent separation of the stabilizer 14 from the compression element 12. In some embodiments, the stabilizer 14 may be disengaged from the compression member 12 by returning the locking element 16 to the first unlocked position, for example, by rotating the locking element 16 in the opposite direction until the lateral flanges 56 are clear of the overhangs 36.

[0078] 22 is a flowchart illustrating several steps in a method 80 for performing an orthopedic fusion procedure, such as a sacroiliac joint fusion in the human spine. In some embodiments, the first step 82 of the method 80 is to establish a surgical pathway to a surgical target site, which in this exemplary embodiment is the joint between the ilium and sacrum of a human patient. By way of example only, the fusion procedure may be performed at any level of the sacrum, including, but not limited to, one or more of the S1, S2, and S3 spinal levels. Notably, implantation of the surgical fixation assembly 10 may achieve sacroiliac joint fusion using an implant at only one level, although the procedure may be repeated at multiple levels if the surgeon desires. In any event, the surgical path may be established by methods commonly known in the surgical arts, including open and / or minimally invasive techniques, along with various substeps, including (but not limited to) (a) determining an access trajectory to the surgical target site (e.g., using robotics or other methods), (b) creating an opening in the patient's skin along the determined access trajectory, (c) dilating the soft tissue between the patient's skin and the surgical target site, and (d) retracting the soft tissue to maintain the surgical path and provide the surgeon with better visibility through the dilated opening. In some embodiments, any of substeps (a)-(d) may be performed manually or robotically, using a robotic platform 98 such as that shown in FIG. 23.

[0079] In some embodiments, a second step 84 of method 80 is to determine the size (e.g., length and / or diameter) of compression member 12 to be used in the procedure. In some embodiments, this step may be accomplished using a depth gauge. In some embodiments, this step may be accomplished using robotics.

[0080] In some embodiments, a third step 86 of method 80 is securing compression member 12 to driver instrument 100 with drill bit 102 of driver instrument 100 extending through central lumen 30 of compression member 12 and extending distally beyond distal end 22 of compression member 12, as shown by way of example only in FIG. 24 . In some embodiments, compression member 12 may be secured to driver instrument 100 by threaded engagement between proximal end 20 of compression member 12 and driver instrument 100.

[0081] In some embodiments, a fourth step 88 of method 80 is inserting compression member 12 through a first bone segment (e.g., the patient's ilium 5) and into a second bone segment (e.g., the patient's sacrum 7) so that proximal end 20 of compression member 12 is seated within ilium 5, distal end 22 of compression member 12 is seated within sacrum 7, and central portion 24 of compression member 12 extends across sacroiliac joint 9, as shown by way of example in FIGS. 26 and 28 . By way of example, compression member 12 can be inserted at any one of sacral levels S1, S2, or S3 to achieve sacroiliac joint fixation, or at multiple levels if so desired. In some embodiments, drill bit 102 rotates faster (e.g., twice as fast) than compression member 12. In some embodiments, the drill bit 102 and compression member 12 rotate in opposite directions (e.g., the drill bit 102 rotates clockwise while the compression member 12 rotates counterclockwise, or the drill bit 102 rotates counterclockwise while the compression member 12 rotates clockwise). In some embodiments, insertion may continue until the drill bit 102 penetrates the sacral cortex.

[0082] In some embodiments, a fifth step 90 of method 80 is to remove driver instrument 100 once compression member 12 is seated in the desired position as described above. By way of example, removal of driver instrument 100 may include the substeps of separating the driver instrument from compression member 12 and withdrawing driver instrument 100 from the surgical channel.

[0083] In some embodiments, a sixth step 92 of method 80 includes coupling stabilizer 14 to compression member 12 after compression member 12 has been implanted, as described herein. In some embodiments, this step 92 of method 80 may be accomplished by first coupling stabilizer 14 to an insertion instrument, for example, by threadingly engaging an insertion instrument (not shown) with threaded opening 60 of stabilizer 14. Next, stabilizer 14 is advanced through the surgical pathway and coupled to compression member 12 by distally advancing guide rail 48 of stabilizer 14 along elongated track 32 of compression member 12 until proximal coupler 44 of stabilizer 14 seats within proximal recess 30 of compression member 12. As the stabilizer 14 advances along the compression member 12, the elongated body 42 displaces bone material to either side, which places a force back on the elongated body 42 to hold the stabilizer 14 in place, thereby preventing rotation of the compression member 12.

[0084] It should be noted that in practice, the compression member 12 may be inserted into the patient slightly off-target. Rather than removing and reinserting the compression member 12, this can be advantageously addressed by selectively positioning the stabilizer 14 to extend laterally from the compression member 12 to overcome the misaligned implant and achieve a solid fusion without revision. The orientation of the stabilizer 14 can be changed prior to inserting the stabilizer 14 by rotating the compression member 12 to orient the elongated track 32 in the desired direction of extension of the stabilizer 14.

[0085] In some embodiments, a seventh step 94 of the method 80 is engaging the locking element 16 to prevent backout or separation of the stabilizer 14 from the compression member 12. As described above with reference to FIGS. 20-21 , once the stabilizer 14 is fully coupled with the compression element 12, the locking element 16 can be engaged to secure the coupling between the compression element 12 and the stabilizer 14. To accomplish this, the locking element 16 can be rotated such that the one or more lateral flanges 56 are moved from an initial unlocked position (see, e.g., FIG. 20 ), in which the lateral flanges 56 are aligned with the elongated body 42 and not positioned below the one or more ledges 36, to a locked position (see, e.g., FIG. 21 ), in which the lateral flanges 56 are aligned with the elongated body 42 and not positioned below the one or more ledges 36 and within the radial grooves 38. When the lateral flanges 56 are in this second, locked position, the ledges 36 prevent separation of the stabilizer 14 from the compression member 12. At this point, the surgical fixation assembly 10 is fully implanted and locked, as shown by way of example in Figures 26-28.

[0086] In some embodiments, an eighth step 96 of the method includes removing remaining instrumentation from the surgical channel and closing the incision.

[0087] In some embodiments, the method 80 can include a first step (or a prior step) of inserting an implant member into the sacroiliac joint, for example, using a posterior insertion technique. In some embodiments, the implant may have holes that help determine the trajectory of the incoming implant, similar to, for example, a femoral nail. The substep of determining the access trajectory would then be modified to align the access trajectory with at least one of the holes in the graft. The procedure then proceeds as described herein.

[0088] In some embodiments, the compression member 12 may be provided in a variety of shapes and sizes. For example, FIGS. 29-32 illustrate a compression member 12 with an elongated shaft 18 having a longer length and a smaller diameter than the compression member 12 described above. Most features of the compression member 12 shown in FIGS. 29-32 are the same as those described above, except for the more prominent head 19, which is necessary to provide the proximal recess 30, ridge 36, and radial groove 38 with the same size dimensions as the compression member 12 described above. This ensures that the same (or identical) stabilizer 14 can be used with any size compression member 12, thereby reducing costs, improving efficiency, and reducing potential errors associated with providing users with kits containing various sizes of compression members 12 with stabilizers 14 that can be used with any of the compression members 12.

[0089] 33-34 illustrate a surgical fixation implant 110 according to another embodiment of the present disclosure. By way of example only, the surgical fixation implant 110 includes a compression member 112, a stabilizer 114, and a linkage element 116. In some embodiments, the compression member 112 may comprise a bone anchor having a cylindrical elongated shaft 118 having a proximal end 120, a distal end 122, and a central portion 124 positioned between the proximal and distal ends 120, 122. In some embodiments, the compression member 112 may further comprise one or more helical threads 126 disposed about the outer surface of the elongated shaft 118. By way of example, in a sacroiliac joint fusion procedure, the compression member 112 may be positioned such that the distal end 122 engages the sacrum 5 and the proximal end 124 engages the ilium 7, as described above.

[0090] In some embodiments, the compression member 112 includes a connecting element 116 configured to receive at least a portion of the stabilizer 114 and connect the stabilizer 114 to the compression member 112. For example, the connecting element 116 in this exemplary embodiment comprises a cap or washer 128 connected to the proximal end 120 of the compression member 112 and having a lateral flange 129 with an opening 130 configured to receive at least a portion of the stabilizer 114 therethrough to capture and hold the stabilizer 114 at a desired angular orientation relative to the compression member 112 during in situ assembly. In some embodiments, the angular orientation of the stabilizer 114 relative to the compression member 112 may range from 0-30°. In some embodiments, the angular orientation of the stabilizer 114 relative to the compression member 112 is approximately 22°. In embodiments, the angular orientation of the stabilizer 114 relative to the compression member 112 may have an extreme angulation of approximately 28°. In some embodiments, the cap or washer 128 may have a "figure eight" shape. In some embodiments, the elongate shaft 118 may further include one or more lateral openings 140 configured to allow the compression member 112 to pass through and allow bone fusion.

[0091] In some embodiments, stabilizer 114 includes a secondary anchor that can be threadably engaged with aperture 130. In some embodiments, stabilizer 114 includes a secondary anchor that passes through aperture 130 but is not threadably engaged with aperture 130.

[0092] 35-36 illustrate an example of a surgical fixation implant 210 according to some embodiments of the present disclosure. By way of example, the surgical fixation implant 210 may be used in a variety of surgical procedures at various locations throughout the body. In some embodiments, the surgical fixation implant 210 disclosed herein may be optimized for use in a sacroiliac joint fusion procedure in the spine of a human patient. By way of example, the surgical fixation implant 210 includes a compression member 212 and a stabilizer 214 configured to be coupled to the compression member 212 in situ (e.g., after the compression member 212 is implanted in a surgical target site) and secured in place by a guide cap or washer 216.

[0093] In some embodiments, compression member 212 may comprise any device configured to engage two separate bone portions and hold the two separate bone portions in position relative to one another. In some embodiments, compression member 212 may comprise a bone anchor having a cylindrical elongated shaft 218 having a proximal end 220, a distal end 222, and a central portion 224 positioned between proximal end 220 and distal end 222. In some embodiments, compression member 212 may further comprise one or more helical threads 226 disposed about the outer surface of elongated shaft 218. In some embodiments, helical thread 226 may have multiple pitch zones, e.g., a cortical bite zone at proximal end 220 and a cancellous pitch zone at distal end 222, configured to obtain bite into different types of bone. By way of example, in a sacroiliac joint fusion procedure, compression member 12 may be positioned such that distal end 222 engages sacrum 5 and proximal end 224 engages ilium 7, as described above.

[0094] In some embodiments, compression member 212 further includes a central lumen 228 extending longitudinally between proximal end 220 and distal end 222. By way of example only, central lumen 228 may have a generally cylindrical cross-section and is configured to allow one or more surgical instruments or accessories to pass through the compression member, including, but not limited to, guide wires and / or drill bits and / or guide posts 230 for stabilizers 214.

[0095] In some embodiments, compression member 212 includes a coupling mechanism configured to receive at least a portion of stabilizer 214 to couple stabilizer 214 to compression member 212. For example, compression member 212 of this exemplary embodiment includes a coupling mechanism comprising a guidepost 230 having an elongated shaft 232 configured to extend through central lumen 228 and a proximal circumferential recess 234 configured to receive at least a portion of proximal coupler 244 of stabilizer 214 therein. By way of example, elongated shaft 232 may have a threaded distal end 236 to enable secure coupling with stabilizer 214.

[0096] In some embodiments, the elongate shaft 218 may further include one or more lateral openings 240 configured to allow bone fusion through the compression member 212. In some embodiments, the elongate shaft 18 may include multiple openings 40 that form a bone growth promoting lattice.

[0097] In some embodiments, stabilizer 214 comprises any device or element configured to couple with compression member 212 in situ to prevent rotation and / or other movement of compression member 212 while implanted in bone. In some embodiments, stabilizer 214 functions as a coupleable flange that is associated with compression member 212 after compression member 212 is implanted in bone, preventing rotation of compression member 212 by providing a physical barrier with an extended surface area that abuts against the bone to prevent rotation.

[0098] In this exemplary embodiment, stabilizer 214 comprises an elongate body 242 and a proximal coupler 244. In some embodiments, elongate body 242 may have a shaped cross-section. In some embodiments, elongate body 242 may have a cross-section having a triangular shape. In some embodiments, the triangular shape may be oriented such that the apex of the triangle is pointed laterally away from compression member 212 when stabilizer 214 is coupled to compression member 212. By way of example, elongate body 242 may have any cross-sectional shape capable of providing sufficient surface area to engage bone. In some embodiments, stabilizer 214 may have a tapered distal end 252 to facilitate more efficient insertion into bone with minimal disruption.

[0099] In some embodiments, the proximal coupler 244 is sized and shaped to mate with the circumferential recess 234 of the guide post 230. In some embodiments, the guide post 230 extends through a first opening 270 in the guide cap or washer 216 into the central lumen 228 and threadingly engages a distal surface of the central lumen 228, while the elongated body 242 of the stabilizer 214 extends through a second opening 272 laterally offset from the first opening 270. In this manner, the stabilizer 214 is secured to the compression member 212.

[0100] 37-38 show an example of an alignment bracket 310 configured for use with the surgical fixation assembly 10 and associated instruments described herein, providing an insertion tool 312 for an interbody spacer 314 and a rigid arm 316 that can be positioned along the inserter shaft 312 before or during a procedure to reduce steps, enable a low-cost alternative to robotics, or enable VR and navigation as a trajectory guide. Multiple drill guide options can be provided on the arm. In some embodiments, the rigid arm 316 includes a proximal end 318 that includes one or more through-holes 320 aligned with the interbody spacer 314 to guide the instrument on a determined insertion trajectory.

[0101] The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically. The use of the words "a" or "an" when used in conjunction with the term "comprising" in the claims and / or specification can mean "one," but is also consistent with the meaning of "one or more" or "at least one." The term "about" generally means ±5% of the stated value. The use of the term "or" in the claims is used to mean "and / or" unless expressly indicated to refer to alternatives only, or unless the alternatives are mutually exclusive, although the present disclosure supports a definition that refers to alternatives only and "and / or."

[0102] The terms "comprise" (and any form of "comprise", such as "comprises" and "comprising"), "have" (and any form of "have", such as "has" and "having"), "include" (and any form of "include", such as "includes" and "including"), and "contain" (and any form of "contain", such as "contains" and "containing") are open-ended linking verbs. Consequently, a method or device that "comprises", "has", "includes", or "contains" one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Similarly, a method step or device element that "comprises", "has", "includes", or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, an apparatus or structure that is constructed in a certain way may be constructed in at least that way, but not in unrecited ways.

[0103] All patents and publications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this disclosure pertains. Although particular forms of the present disclosure have been shown, it should be understood that they are not limited to the specific forms or arrangements described and shown herein. It will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the present disclosure, and that the present disclosure should not be considered limited to what has been shown and described herein, and any drawings / figures contained herein.

[0104] Those skilled in the art will readily appreciate that the present disclosure is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures, and techniques described herein are presently representative of preferred embodiments and are intended to be illustrative, not limiting in scope. Modifications therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the disclosure and defined by the appended claims. While the present disclosure has been described in connection with certain preferred embodiments, it should be understood that the present disclosure as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the disclosure which are obvious to those skilled in the art are intended to be within the scope of the following claims.

Claims

1. a compression member comprising a cylindrical body having a proximal end, a distal end, an intermediate portion extending longitudinally between the proximal and distal ends, a first bone engaging feature positioned at the proximal end, a second bone engaging feature positioned at the distal end, and a stabilizer engaging feature positioned on an outer surface of the compression member; an independent stabilizer configured to couple to the compression member by interacting with the stabilizer engagement mechanism, the stabilizer comprising an elongated body having a third bone engagement mechanism and a coupling mechanism; and a locking element rotatably coupled to the stabilizer, the locking element configured to move between a first position that allows movement of the stabilizer relative to the compression member before or during coupling of the stabilizer and the compression member, and a second position that prevents movement of the stabilizer relative to the compression member after coupling of the stabilizer and the compression member; 1. A surgical fixation assembly comprising:

2. The assembly of claim 1 , wherein the first bone-engaging feature comprises a helical thread disposed about the outer surface of the cylindrical body at the proximal end.

3. The assembly of claim 1 , wherein the second bone-engaging feature comprises a helical thread disposed about the outer surface of the cylindrical body at the distal end.

4. The assembly of claim 1 , wherein the stabilizer engagement feature comprises a longitudinal recess formed in the outer surface of the cylindrical body and extending between the proximal end and the distal end.

5. The assembly of claim 4 , wherein the longitudinal recess is configured to slidably receive at least a portion of the stabilizer therein.

6. The assembly of claim 1 , wherein the compression member has an inner lumen extending longitudinally through the elongate body between the first end opening and the second end opening.

7. The assembly of claim 1 , wherein the compression member includes at least one side opening formed in the elongate body.

8. The assembly of claim 1 , wherein the stabilizer has a triangular cross-sectional shape.

9. The assembly of claim 1 , wherein the stabilizer has at least one lateral opening formed therein.

10. The assembly of claim 1 , wherein the locking element has at least one lateral flange configured to engage the compression member when the locking element is in the second position.

11. 1. A method of fusing a first bone segment and a second bone segment across a joint between the first and second bone segments, comprising: establishing a surgical pathway to a surgical target site; attaching a compression member to a driver instrument having an elongated drill bit at a distal end, the compression member comprising: a cylindrical body having a proximal end, a distal end, an intermediate portion extending longitudinally between the proximal end and the distal end, a first bone engaging feature positioned at the proximal end, a second bone engaging feature positioned at the distal end, a stabilizer engaging feature positioned on an outer surface of the compression member, and an inner lumen extending longitudinally through the elongated body between an opening at the first end and an opening at the second end; implanting the compression member into the surgical target site by rotatably advancing the compression member through the first bone segment, across the joint and into the second bone segment until the second bone engaging feature is seated in the second bone segment, the first bone engaging feature is seated in the first bone segment and the intermediate portion extends across the joint; advancing an independent stabilizer through the surgical channel toward the implanted compression member; coupling the independent stabilizer to the implanted compression member in situ such that the implanted compression member is prevented from rotating relative to the first bone segment and the second bone segment; and rotating a locking element coupled to the stabilizer from a first position that allows movement of the stabilizer relative to the compression member to a second position that prevents movement of the stabilizer relative to the compression member when the stabilizer and the compression member are in situ coupled; A method for providing

12. 12. The method of claim 11, wherein the compression member is secured to the driver instrument such that a distal tip portion of the elongated drill bit extends through the internal lumen of the compression member and protrudes distally from the distal end of the compression member.

13. The step of implanting the compression member within the surgical target site comprises: advancing the driver instrument having a fixed compression member distally through the surgical channel until the distal tip portion of the drill bit contacts the first bone segment; and the substep of rotating the drill bit and compression member. The method of claim 12, comprising:

14. The method of claim 12, wherein the driver instrument is detached from the compression member and removed from the surgical channel prior to performing the stabilizer installation step.

15. The method of claim 11 , wherein the first bone-engaging feature comprises a helical thread disposed about the outer surface of the cylindrical body at the proximal end.

16. The method of claim 11 , wherein the second bone-engaging feature comprises a helical thread disposed about the outer surface of the cylindrical body at the distal end.

17. the step of in situ coupling the stand-alone stabilizer to the implanted compression member comprises: positioning a portion of a coupling element provided on the stabilizer within a portion of the stabilizer engagement mechanism of the compression member; and advancing the stabilizer distally along the compression member by slidably translating the coupling element within the stabilizer engagement mechanism. The method of claim 11 , comprising:

18. The method of claim 17 , wherein the coupling element comprises an elongated guide rail and the stabilizer engagement feature comprises an elongated track.

19. The method of claim 18 , wherein the elongated guide rail is secured within the elongated track using a dovetail mechanism.

20. The method of claim 11 , wherein the locking element has at least one lateral flange configured to engage the compression member when the locking element is in the second position.

Images