Expandable intervertebral devices and instruments

Abstract

The present technology relates generally to expandable intervertebral devices and associated devices, systems, and methods. In some embodiments, the intervertebral devices are configured to transition between a number of different states, for example, between an unexpanded state and an expanded state. Expansion of the intervertebral devices can include, for example, horizontal / lateral expansion and vertical / lordotic expansion. In some embodiments, the intervertebral devices include locking features configured to retain or "lock" the intervertebral device in the expanded state, for example, to prevent the intervertebral device from transitioning away and / or dislodging from the expanded state.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates generally to the field of spinal surgery, and more particularly to expandable intervertebral devices used in fusing adjacent vertebrae.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 488,757, filed March 6, 2023, which is incorporated by reference in its entirety. [Background technology]

[0003] In the spinal column, which is made up of vertebrae, intervertebral discs and / or vertebral bodies may become misaligned or damaged due to trauma, disease, degenerative disorders, or wear and tear over time. One result of this misalignment or damage to the spinal discs or vertebral bodies may be chronic back pain. A common procedure to treat spinal disc or vertebral body injuries or diseases may involve partial or complete removal of the intervertebral disc. An implant, sometimes called an interbody spacer, i.e., an intervertebral implant, may be inserted into the cavity created by the removal of the disc to help maintain spinal height and / or restore stability to the spine. Interbody spacers can also provide lordotic correction to spinal curvature. One example of a commonly used interbody spacer is a fixed dimensional cage, which is typically loaded with bone and / or bone growth-inducing substances. Summary of the Invention [Problem to be solved by the invention]

[0004] One drawback of spacers known in the prior art is that they may be of a fixed height and / or footprint and may not provide adequate or accurate height restoration and support between affected vertebral bodies. Fixed-size cages may also require invasive procedures to allow implantation because of their necessarily large pre-implant size. Therefore, there is a need for an intervertebral implant that can be inserted along a single axis and yet can be expanded to provide intervertebral support, lordosis correction, or the like. [Means for solving the problem]

[0005] In accordance with the present invention, expandable intervertebral devices and associated devices, systems, and methods are provided. In some embodiments, the expandable intervertebral devices are configured to transition between a number of different states, for example, between an unexpanded state and an expanded state. Expansion of the intervertebral device can include, for example, horizontal / lateral expansion and vertical / lordotic expansion. In some embodiments, the intervertebral devices include locking features configured to retain or "lock" the intervertebral device in the expanded state, for example, to prevent the intervertebral device from transitioning away and / or dislodging from the expanded state.

[0006] The exemplary embodiments of the present invention will be best understood by referring to the drawings. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a lateral view of a spinal surgical system and a patient's spine according to embodiments of the present disclosure. [Figure 2A] FIG. 1 is a side view of an intervertebral device in an unexpanded configuration and positioned within a vertebral body in accordance with an embodiment of the present disclosure. [Figure 2B] FIG. 2B is a side view of the intervertebral device of FIG. 2A in an expanded configuration. [Figure 3A] FIG. 1 is a perspective view of an intervertebral device in a delivery state and configured in accordance with embodiments of the present technology. [Figure 3B] FIG. 3B is a rear view of the intervertebral device of FIG. 3A. [Figure 3C] FIG. 3B is a front end view of the intervertebral device of FIG. 3A. [Figure 3D] FIG. 3B is a side view of the intervertebral device of FIG. 3A. [Figure 3E] FIG. 3B is a top view of the intervertebral device of FIG. 3A. [Figure 3F] FIG. 3B is an exploded plan view of the intervertebral device of FIG. 3A. [Figure 3G] FIG. 3B is a perspective view of a first end body of the intervertebral device of FIG. 3A. [Figure 3H] FIG. 3B is a side view of a first end body of the intervertebral device of FIG. 3A. [Figure 3I] FIG. 3B is a perspective view of a second end body of the intervertebral device of FIG. 3A. [Figure 3J] FIG. 3B is a side view of the second end body of the intervertebral device of FIG. 3A. [Figure 3K] FIG. 3B is a perspective view of a support of the intervertebral device of FIG. 3A. [Figure 3L] FIG. 3B is a side view of a support of the intervertebral device of FIG. 3A. [Figure 3M] 3B is a perspective view of a link of the intervertebral device of FIG. 3A. [Figure 3N] 3B is a perspective view of a link of the intervertebral device of FIG. 3A. [Figure 3O] 3B is a cross-sectional view of a link of the intervertebral device of FIG. 3A. [Figure 4A] FIG. 3B is a perspective view of the intervertebral device of FIG. 3A in an outwardly expanded state in accordance with an embodiment of the present technology. [Figure 4B] FIG. 4B is a top view of the intervertebral device of FIG. 4A. [Figure 4C] FIG. 4B is an end view of the intervertebral device of FIG. 4A. [Figure 4D] FIG. 4B is a side view of the intervertebral device of FIG. 4A. [Figure 5A] FIG. 3B is a perspective view of the intervertebral device of FIG. 3A in an outwardly and vertically expanded state in accordance with embodiments of the present technology. [Figure 5B] FIG. 5B is a top view of the intervertebral device of FIG. 5A. [Figure 5C] 5B is a cross-sectional view of the intervertebral device of FIG. 5A. [Figure 5D] FIG. 5B is a side view of the intervertebral device of FIG. 5A. [Figure 6A] FIG. 3B is a top view of selected views of the intervertebral device of FIG. 3A, with other views of the intervertebral device omitted for clarity of the drawing. [Figure 6B] FIG. 3B is a side view of selected views of the intervertebral device of FIG. 3A, with other views of the intervertebral device omitted for clarity of the drawing. [Figure 6C] FIG. 3B is a side view of selected views of the intervertebral device of FIG. 3A, with other views of the intervertebral device omitted for clarity of the drawing. [Figure 6D] 3B is a side view of selected views of the intervertebral device of FIG. 3A, with the views of the intervertebral device omitted for clarity of the drawing. FIG. [Figure 6E] 3B is a side view of selected views of the intervertebral device of FIG. 3A, with the views of the intervertebral device omitted for clarity of the drawing. FIG. [Figure 6F] 3B is a side view of selected views of the intervertebral device of FIG. 3A, with the views of the intervertebral device omitted for clarity of the drawing. FIG. [Figure 6G] FIG. 5B is a plan view of a selected perspective of the intervertebral device of FIG. 5A. [Figure 6H] 5B is a side view of a selected perspective of the intervertebral device of FIG. 5A. FIG. [Figure 6I] 5B is a side view of a selected perspective of the intervertebral device of FIG. 5A. FIG. [Figure 7A] FIG. 10 is a side view of an intervertebral device in accordance with an embodiment of the present technology. [Figure 7B] FIG. 10 is a side view of an intervertebral device in accordance with an embodiment of the present technology. [Figure 7C] FIG. 10 is a side view of an intervertebral device in accordance with an embodiment of the present technology. [Figure 7D] FIG. 10 is a side view of an intervertebral device in accordance with an embodiment of the present technology. [Figure 7E] FIG. 10 is a side view of an intervertebral device in accordance with an embodiment of the present technology. [Figure 8A] FIG. 10 is a perspective view of another intervertebral device in a delivery configuration in accordance with an embodiment of the present technology. [Figure 8B] FIG. 10 is a side view of another intervertebral device in a delivery configuration in accordance with embodiments of the present technology. [Figure 9A] FIG. 8B is a perspective view of the intervertebral device of FIG. 8A in an outwardly expanded state in accordance with embodiments of the present technology. [Figure 9B] FIG. 8C is a side view of the intervertebral device of FIG. 8B in an outwardly expanded state in accordance with embodiments of the present technology. [Figure 10A] 8B is a perspective view of the intervertebral device of FIG. 8A in a second condition 811b in accordance with embodiments of the present technology. [Figure 10B] FIG. 8C is a side view of the intervertebral device of FIG. 8B in a second condition 811b in accordance with embodiments of the present technology. [Figure 11A] 8C is a perspective view of the intervertebral device and delivery tool of FIGS. 8A and 8B, with the intervertebral device in a first position. FIG. [Figure 11B] 8C is a cross-sectional view of the intervertebral device and delivery tool of FIGS. 8A and 8B when the intervertebral device is in a first position. [Figure 11C] 8C is a perspective view of the intervertebral device and delivery tool of FIGS. 8A and 8B, with the intervertebral device in a first position. FIG. [Figure 12A] 11A-11C, showing a perspective view of the intervertebral device of FIGS. 8A and 8B and the delivery tool of FIGS. 11A-11C, with the intervertebral device of FIGS. 8A and 8B in a second position. [Figure 12B] 11A-11C, a cross-sectional view of the intervertebral device of FIGS. 8A and 8B and the delivery tool of FIGS. 11A-11C, with the intervertebral device of FIGS. 8A and 8B in a second position. [Figure 12C] 11A-11C, a cross-sectional view of the intervertebral device of FIGS. 8A and 8B and the delivery tool of FIGS. 11A-11C, with the intervertebral device of FIGS. 8A and 8B in a second position. [Figure 13A] 11A-11C after actuation of the delivery tool to translate the vertebral body toward an intermediate state. FIG. [Figure 13B]11A-11C after actuation of the delivery tool to translate the vertebral body toward an intermediate state. FIG. [Figure 13C] 11A-11C after actuation of the delivery tool to translate the vertebral body toward an intermediate state. FIG. [Figure 13D] 11A-11C after actuation of the delivery tool to translate the vertebral body toward an intermediate state. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present technology generally relates to expandable intervertebral devices and related devices, systems, and methods. In some embodiments, the intervertebral device is configured to transition between a number of distinct states, for example, a first state (e.g., unexpanded, low-profile, delivery, etc.), an intermediate state (e.g., partially expanded, laterally expanded, horizontally expanded, etc.), and / or a second state (e.g., expanded, lordotic, vertically and horizontally expanded, implanted, etc.). Expansion of the intervertebral device can include, for example, horizontal / lateral expansion, vertical / lordotic expansion, unilateral expansion, bilateral expansion, or combinations thereof. In some embodiments, the intervertebral device is configured to expand in stages, for example, to achieve a subsequent expansion, for example, vertical expansion after horizontal / lateral expansion. In some embodiments, the intervertebral device is configured to expand / contract in stages, for example, in one or more stages of simultaneous expansion / contraction (e.g., vertical expansion / contraction and horizontally / lateral expansion / contraction), sequential expansion stages, etc. The number, sequence, and motion (eg, expansion / contraction) of these steps can be selected based on the procedure to be performed.

[0009] Intervertebral devices may include locking features that secure or "lock" the intervertebral device in the expanded state, e.g., to inhibit or prevent the intervertebral device from transitioning away from the expanded state and / or from dislodging. The locking features may be integral with (e.g., a part of) the intervertebral device. Intervertebral devices with locking features are expected to be easier to use, at least because the intervertebral device can be secured in the expanded state without the use of externally supplied locking components, e.g., locking screws. This may reduce the number of tools and components inserted into the patient's body during the implantation procedure, which is expected to increase the speed with which the implantation procedure can be performed and / or at least partially reduce the risk of damage to the patient's tissue. Additionally or alternatively, the intervertebral devices of the present technology can be used without locking screws, allowing bone graft material (and / or spinal treatment material) to be carried or delivered through the intervertebral device without creating a pathway for a locking screw, which is expected to further increase the speed of the implantation procedure and / or reduce the number of tools and components inserted into the patient's body during the implantation procedure.

[0010] Intervertebral devices can be transitioned between states, e.g., in situ after placement within the intervertebral space, or at other anatomical locations. Intervertebral devices can be configured for spinal procedures, e.g., to treat fractures (e.g., compression fractures), restore vertebral dimensions (e.g., vertebral height), and / or otherwise. In at least some embodiments, the intervertebral devices can be expandable to at least partially occupy the intervertebral space, e.g., extending between adjacent vertebral bodies. In the expanded state, the intervertebral device can contact one or more surfaces defining the intervertebral space, e.g., the inferior surface of the superior vertebral body and / or the superior surface of the inferior vertebral body, and / or one or more portions thereof. In some embodiments, the intervertebral device can assume a curved or angled configuration in the expanded state, e.g., to at least partially correct the lordotic angle of the patient's spine and / or otherwise adjust the relative position and / or alignment of one or more vertebral bodies of the patient's spine.

[0011] A delivery tool, driver, actuation mechanism, etc. may be used to deploy the intervertebral device within the disc space and / or lock the intervertebral device in an expanded state. In at least some embodiments, the delivery tool may be configured to transition the intervertebral device from a non-expanded state to an expanded state and / or to unlock (disengage) a locking feature on the intervertebral device, thereby transitioning the intervertebral device from an expanded state toward a non-expanded state.

[0012] A. Overview of target anatomical structures FIG. 1 is a side view of a spinal surgical system 100 (“system 100”) positioned along the spinal column S of a human patient, according to one embodiment of the present disclosure. System 100 may include one or more instruments 102 and a retractor or cannula 104 (“retractor 104”). One or more of instruments 102 may be delivered through cannula 104 to perform a surgical procedure. For example, at least some of instruments 100 may be configured to deliver intervertebral devices (which may also be referred to as interbody devices, interbody spacers, interbody cages, and / or the like), such as any of the intervertebral devices described above and / or cited by reference herein. Retractor 104 may be configured to enable access via different pathways, such as an ALIF pathway, an OLIF pathway, an LLIF pathway, an XLIF pathway, a TLIF pathway, and / or a PLIF pathway.

[0013] With continued reference to FIG. 1 , the instrument 102 can be used to prepare the implantation site by, for example, agitating organs or tissue (e.g., agitating neural tissue), removing tissue (e.g., removing bone marrow or intervertebral tissue / disc, removing tissue causing a stenosis, penetrating tissue, etc.), preparing a vertebral body (e.g., roughening or shaping a vertebral endplate or intervertebral facet), or otherwise. In some embodiments, the instrument 102 includes a delivery instrument. The delivery instrument can be inserted into an intervertebral space IS between two vertebrae V (individually shown as a first or upper vertebra V1 and a second or lower vertebra V2). The intervertebral space (“IS”) can be created or enlarged using one or more instruments, including bone drills, osteotomes, scalpels, knives, cutting instruments, etc. Intervertebral devices can be delivered into the intervertebral space through a retractor 120. In some procedures, the instrument 110 may be configured to deliver the intervertebral device through the retractor 104 .

[0014] B. Selected Embodiments of Intervertebral Devices and Related Systems and Methods 2A and 2B are side views of vertebral bodies V1, V2 of FIG. 1 and an intervertebral device 210 ("device 210") positioned within intervertebral space IS in accordance with embodiments of the present technology. More specifically, in FIG. 2A, device 210 is in a first state 211a (which may also be referred to as a shipping state, a folded state, a compact state, a low-profile state, an unexpanded state, and / or the like), and in FIG. 2B, device 210 is in a second state 211b (which may also be referred to as a deployed state, an expanded state, and / or the like). In some embodiments, device 210 is configured to transition to one or more intermediate or partially expanded states, e.g., between first state 211a and second state 211b.

[0015] The instrument 210 can have one or more upper supports 212 and one or more lower supports 214. In the first state 211a, each of the upper and lower supports 212, 214 can be spaced apart from one or both of the vertebral bodies V1, V2. In the second state 212b, each of the upper and lower supports 212, 214 can contact at least one of the vertebral bodies V1, V2. In the illustrated embodiment, for example, when the instrument 210 is in the second state 211b, one or more of the upper supports 212 contact the first vertebral body V1 and one or more of the lower supports 214 contact the second vertebral body V2. In the second state 211b, the instrument 210 may be configured to treat the patient's spine, for example, by at least partially correcting the alignment of one or both of the vertebral bodies V1, V2 and / or stabilizing the position of the vertebral bodies V1, V2 relative to one another.

[0016] 3A-3F are diagrams of an intervertebral device 310 ("device 310") configured in accordance with embodiments of the present technology. More specifically, FIG. 3A is a perspective view of device 310 in a first condition 211a, FIG. 3B is an end view of device 310, FIG. 3C is another end view of device 310, FIG. 3D is a side view of device 310, FIG. 3E is a top view of device 310, and FIG. 3F is an exploded view of device 310. At least some aspects of device 310 may be substantially the same or identical in structure and / or function to device 210 of FIGS. 2A and 2B. Accordingly, like names and / or like reference numbers (e.g., upper support 312 versus upper support 212) are used to indicate substantially the same or identical aspects.

[0017] 3A-3F together, the device 310 may include one or more upper supports 312 (individually shown in FIGS. 3A-3F as first upper support 312a and second upper support 312b), one or more lower supports 314 (individually shown in FIGS. 3A-3F as first lower support 314a and second lower support 314b), a first or front end body or assembly 316 ("first end body 316"), a second or rear end body or assembly 318 ("second end body 318"), and one or more links or transition members 320 (individually shown as first link 320a, second link 320b, third link 320c, and fourth link 320d). In the first state 211a, the upper and lower supports 312, 314 can be positioned between the first end body 316 and the second body 318. Each one of the links 320 can couple (e.g., movably couple, pivotally couple, etc.) at least one of the first or second end bodies 316, 318 to at least one of the upper or lower supports 312, 314. In the illustrated embodiment, for example, a first link 320a couples the first end body 316 to the first upper and lower supports 312a, 314a, a second link 320b couples the second end body 318 to the first upper and lower supports 312a, 314a, a third link 320c couples the first end body 316 to the second upper and lower supports 312b, 314b, and a fourth link 320d couples the second end body 318 to the second upper and lower supports 312b, 314b. Together, the first link 320a, the second link 320b, the first upper support 312a, and the first lower support 314a comprise a first extension assembly 322a that is movable relative to the first and second end bodies 316, 318. Similarly, the third link 320c, the fourth link 320d, the second upper support 312b, and the second lower support 314d may together form a second extension assembly 322b that is movable relative to the first and second end bodies 316, 318.Movement of expansion assemblies 322a, 322b allows device 310 to expand as described in more detail herein (eg, with reference to Figures 4A-6I).

[0018] The first end body 316 can have one or more first locking features or regions 324 and a first attachment port or opening 332. The second end body 318 can have one or more second locking features or regions 326 and a second attachment port or opening 334. Each of the first and second locking features 324, 326 can correspond to one another and be configured to releasably couple with one another. In the illustrated embodiment, for example, each of the second locking features 326 has a notch or recess configured to releasably receive a corresponding end or protrusion of one of the first locking features 324. In some embodiments, the second end body 318 can have a ramped surface or region 328 positioned between the first locking feature 324 and the second locking feature 326, at least when the device 310 is in the first condition 211a. The angled surface 328 can be configured to facilitate mating of the first locking feature 324 and the second locking feature 326. Additionally or alternatively, each of the first locking features 324 can be at least partially positioned between one or more of the supports 312, 314, for example, at least when the device 310 is in the first condition 311a. In the illustrated embodiment, for example, the first and second upper supports 312a, 312b define a recess or first locking feature gap 330 configured to receive at least one of the first locking features 324 when the device 310 is in the first condition 211a. In these and other embodiments, the first attachment opening 332 and the second attachment opening 334 can be aligned to define a lumen or central passageway through the device 310, for example, as shown in FIGS. 3B and 3C .

[0019] In some embodiments, the device 310 can include one or more alignment pegs or posts 336 (individually shown in FIGS. 3A-3F as a first post 336a and a second post 336b). Each of the posts 336 can be positioned at least partially between one or more of the supports 312, 314 and configured to align (e.g., maintain) at least the supports 312, 314 relative to one another when the device 310 is expanded from the first state 211a. In the illustrated embodiment, for example, the first post 336a is positioned at least partially between and configured to align the first upper support 312a and the first lower support 314a, and the second post 336b is positioned at least partially between and configured to align the second upper support 312b and the second lower support 314b.

[0020] 3G and 3H are perspective and side views, respectively, of first end body 316. First end body 316 can include one or more link ports 338 (individually shown in FIG. 3G as first link port 338a, second link port 338b, third link port 338c, and fourth link port 338d). Each of link ports 338 is configured to pivotally couple to one of links 320, as described above with reference to FIGS. 3A-3F.

[0021] Additionally, first end body 316 can include an upper first locking feature 324a positioned on a first side (e.g., an upper side) of first end body 316 and a lower first locking feature 324b positioned on a second side (e.g., a lower side) of first end body 316. Each of first locking features 324 can include an arm or extension portion 340a, 340b and a coupling, barb, hook, or tab portion 342a, 342b. Each of tab portions 342a, 342b can be configured to engage a corresponding one of second locking features 326, as described in further detail below with reference to FIGS. 5A-6I. In the illustrated embodiment, at least a portion of the second end body 318 (FIGS. 3A-3F) can be positioned between a pair of upper and lower first locking features 324a, 324b, which can be configured on opposite sides of the second end body 318.

[0022] The first end body 316 may further include one or more link lock features 344. While only one link lock feature 344 is shown on the third side (e.g., the left side) of the first end body 316, the first end body 316 may include another link lock feature 344 on a fourth side (e.g., the right side) of the first end body opposite the first side. Each of the link lock features 344 may include one or more alignment tabs or protrusions 346 (individually shown in FIGS. 3G and 3H as first alignment tab 346 a and second alignment tab 346 b). In the illustrated embodiment, the first alignment tab 346 a and the second alignment tab 346 b are positioned on opposite sides of the link lock feature 344. As described in further detail herein (e.g., with reference to Figures 6D-6I), the link lock feature 344 may be configured, for example, to inhibit or prevent the device 310 from returning to the first state 211a after the device 310 has been expanded from the first state 211a.

[0023] 3I and 3J are perspective and side views, respectively, of second end body 318. Second end body 318 may include one or more of the link lock features 344 described herein above (see, for example, FIGS. 3G and 3H). Additionally, second end body 318 may include one or more link ports 348 (individually shown in FIG. 3G as first link port 338a, second link port 338b, and third link port 338c). Although not visible in FIG. 3I, second end body 318 may further include a fourth link port opposite third link port 348c. Each of the link ports 348 may be substantially the same in structure and / or function as one or more of the link ports 338 described above herein (e.g., with reference to Figures 3G and 3H), which are configured to pivotally couple to one of the links 320, as described above with reference to Figures 3A-3F. Each of the second coupling features 326 may include a notch or recessed area configured to receive a corresponding one of the first coupling features 324. While only one (e.g., upper) second locking feature 326 and one corresponding (e.g., upper) angled surface 328 are visible in the embodiment shown in Figure 3I, second end body 318 may have another second (e.g., lower) mating feature and corresponding second (e.g., lower) angled surface located on an opposite (e.g., lower) side of second end body 318 relative to the illustrated second locking feature 326 and angled surface 328. As best shown in Figure 3I, mounting port 334 may have a gap 350 that may divide mounting port 334 into portions or halves positioned on each side of gap 310 (e.g., left and right portions / halves).

[0024] 3K and 3L are perspective and side views, respectively, of second lower support 314b. As will be appreciated by those skilled in the art, one or more of the other supports 312, 314 may be substantially the same as or identical to second lower support 314b in structure and / or function. For example, first lower support 314a and / or second upper support 312b may be a mirror image of second lower support 314b (e.g., about the longitudinal axis of device 310) and / or first upper support 312a may be identical to lower support 314b.

[0025] The second lower support 314b may have one or more expansion slots 352 (individually shown in FIGS. 3K and 3L as first expansion slot 352a and second expansion slot 352b). The second expansion slot 352b may be a mirror image of the first expansion slot 352a. Each of the expansion slots 352a, 352b may be configured to receive and be pivotally coupled to one or more of the links 320. For example, the first expansion slot 352a is configured to receive and be pivotally coupled to the third link 320c (e.g., FIG. 3F), and the second expansion slot 352b is configured to receive and be pivotally coupled to the fourth link 320d (e.g., FIG. 3F). Each of the expansion slots 352 may have a beveled surface 354a, 354b. 6A-6I, the device 310 can expand from the first state 211a when the links 320 move through corresponding expansion slots 352 and / or along associated beveled surfaces 354a, 354b. Each of the expansion slots 352 may further include a recess or detent 356a, 356b configured to releasably couple to one of the links 320 when the device 310 is in the second (e.g., expanded) state.

[0026] The second lower support 314b can further include an alignment port 358 that can be positioned between the first expansion slot 352a and the second expansion slot 352b and can be configured to receive a corresponding one of the alignment posts 336. In the illustrated embodiment, for example, the alignment port 358 of the second lower support 314b is configured to receive the second alignment post 336b (e.g., FIG. 3F). Additionally, the second lower support 314b can include a recessed portion 360 that at least partially defines (e.g., defines a first half of) the first locking feature gap 330.

[0027] 3M-3O are a first perspective view, a second perspective view, and an end view, respectively, of one of the links 320. Each of the links 320 can have one or more end body coupling features 362 (individually shown in FIGS. 3M and 3N as upper end body coupling feature 362a and lower end body coupling feature 362b) and one or more support coupling features 364 (individually shown in FIGS. 3M-3O as upper support coupling feature 364a and lower support coupling feature 364b). The end body coupling features 362 and / or the support coupling features 364 can be incorporated into the link 320 to form a unitary, unitary assembly, which can reduce the number of individual components in the device 310. Each of the end body coupling features 362 can be configured to be received by one of the link ports 388, 348 of the first or second end body 316, 318 (FIGS. 3G-3J). Each of the support coupling features 364 can be configured to be received by one of the expansion slots 352 of the supports 312, 314 (FIGS. 3K and 3L). Optionally, one or more of the support coupling features 364 can have a curved or rounded head portion 366b configured to correspond to and be at least partially positionable within one of the detents 356a, 356b (FIG. 3L), as described in further detail herein (e.g., with reference to FIGS. 4B and 6I). In some embodiments, the link 320 can have one or more alignment slots 368 (individually shown in FIG. 3N as first alignment slot 368a and second alignment slot 368b). Each of the alignment slots 368 may be configured to receive a corresponding one of the alignment tabs 346 of one of the link lock features 344 (FIGS. 3G-3J), as described in detail herein (e.g., with reference to FIG. 6D).

[0028] 4A-4D are diagrams of the device 310 in an intermediate state 422c, e.g., between the first state 211a and the second state 211b. More specifically, FIG. 4A is a perspective view of the device 310, FIG. 4B is a plan view of the device 310, FIG. 4C is an end view of the device 310, and FIG. 4D is a side view of the device 310. In the intermediate state 413, the relative positions of one or more features of the device 310 may be different from those in the first state 211a. In the illustrated embodiment, for example, the first end 316 and the second end body 318 are closer together, e.g., along the longitudinal axis X of the device 310, such that the device 310 is shorter and / or longitudinally compressed in the intermediate state 422c compared to the first state 211a. This movement of the first and second end bodies 316, 318 may position the first and second locking features 324, 326 closer together, for example, without binding the first and second locking features together. Continuing to refer to the illustrated embodiment, individual ones of the upper and lower supports 312, 314 are moved away from one another, for example, along the lateral or widthwise axis Y of the device 310, such that the device 310 is widened or laterally expanded relative to the first condition 211a. For example, the first upper and lower supports 312a, 314a are moved in a first direction away from the longitudinal axis X, and the second upper and lower supports 312b, 314b are moved in a second direction opposite the first direction, away from the longitudinal axis X. Individual ones of the links 320 can pivot relative to one or more of the end bodies 316, 318 and / or one or more of the supports 312, 314 in response to relative movement between the end bodies 316, 318 and the supports 312, 314. As described further herein (e.g., with reference to Figures 6A-6I), movement of the links 320 can cause horizontal expansion of the device 310.

[0029] 5A-5D are diagrams of device 310 in second state 211b. More specifically, FIG. 5A is a perspective view of device 310, FIG. 5B is a top view of device 310, FIG. 5C is an end view of device 310, and FIG. 5D is a side view of device 310. In second state 211b, the relative positions of one or more features of device 310 may be different than in first state 211a and / or intermediate state 413. In the illustrated embodiment, for example, first end body 316 and second end body 318 are closer together, e.g., relative to their respective positions in intermediate state 413 and / or to position first locking feature 324 and second locking feature 326 to couple with one another. Continuing to refer to the illustrated embodiment, individual ones of the upper and lower supports 312, 314 are moved away from one another, e.g., along a vertical or elevated direction Z of the instrument 310, such that the instrument 310 is taller or vertically expanded relative to the first state 211a and / or the intermediate state 413. For example, the first upper and lower supports 312a, 314a are moved away from one another in opposite directions along the vertical axis Z, and the second upper and lower supports 312b, 314b are moved away from one another in opposite directions along the vertical axis Z. Individual ones of the links 320 can move relative to one or more of the supports 312, 314 in response to movement of the end bodies 316, 318. As described in more detail herein (e.g., with reference to FIGS. 6A-6I), movement of the links 320 can cause vertical expansion of the instrument 310.

[0030] 6A-6I illustrate selected perspectives of device 310 at various stages of expansion, with other perspectives of device 310 omitted for clarity. More specifically, FIGS. 6A-6C illustrate a top view and two side views of device 310 in first state 211a, FIGS. 6D-6F illustrate a top view and two side views of device 310 in intermediate state 413, and FIGS. 6G-6I illustrate a top view and two side views of device 310 in second state 211b. Referring together to FIGS. 6A-6F, as device 310 transitions from first state 211a to intermediate state 413, first end body 316 and second end body 318 can move inward toward each other. Because the third and fourth links 320c, 320d pivotally connect the first and second end bodies 316, 318 to the second lower support 314b (e.g., via respective expansion slots 352a, 352b), inward movement of the first and second end bodies 316, 318 causes the third and fourth links 320c, 320d to pivot relative to the first and second end bodies 316, 318 and the second lower support 314b, thereby moving the second lower support 314b away from the first and second end bodies 316, 318 and transitioning the device 310 from the first state 211a toward the intermediate state 413.

[0031] 6D-6I , further movement of the first and second end bodies 316, 318 can transition the device 310 from the intermediate state 413 toward and / or to the second state 211b. In the intermediate state 413, the link locking features 344 of the first and second end bodies 316, 318 can engage the third and fourth links 320c, 320d (best shown in FIG. 6I ), thereby restricting or preventing further rotation of the third and fourth links 320c, 320d relative to the first and second end bodies 316, 318. For example, the alignment tabs 346 ( FIGS. 3G-3J ) of the link locking features 344 can be at least partially positioned within the alignment slots 368 ( FIGS. 3M-3O ) of the links 320. Thus, further movement of the first end body 316 and the second end body 318 toward one another can cause the third and fourth links 320c, 320d to move along the corresponding expansion slots 352a, 352b. This movement of the third and fourth links 320c, 320d can cause the third and fourth links 320c, 320d to contact and move along the sloped surfaces 354a, 354b of the associated expansion slots 352a, 352b, thereby causing vertical movement (e.g., expansion) of the second lower support 314b relative to the third and fourth links 320c, 320d. Thus, device 310 can effect vertical expansion after (e.g., only after) undergoing horizontal expansion, which is expected to reduce or prevent contact between vertebrae / spinal cord and nerve roots, for example, by increasing the distance between individual vertebral bodies while maintaining the curvature of at least a portion of the patient's spinal column (e.g., when the intervertebral device is in second state 211b). Additionally or alternatively, device 310 can effect horizontal folding after (e.g., only after) device 310 has effected vertical / lordotic folding, which can help maintain device 310 in a horizontally expanded state during a procedure to reposition device 310, for example, when vertical / lordotic folding is desired, although maintaining the device in a horizontally expanded state is advantageous.Because the link locking feature 344 can arrest or prevent further rotation of the third and fourth links 320c, 320d relative to the first and second end bodies 316, 318, it is anticipated that the device 310 can be transitioned between the intermediate state 413 and the second state 211b while maintaining horizontal expansion of the device 310. Thus, the device 310 may be repositioned within the patient without, or substantially without, having to return the device 310 to the first state 211a. This may increase the speed at which a user can reposition the device 310 during an implantation procedure.

[0032] Additionally, as the first body 316 and the second body 318 are brought closer together, the first locking feature 324 can engage with the corresponding locking feature 326, thereby securing or locking the device in the second state 211b. For example, with reference to FIG. 6G, as the first end body 316 and the second end body 318 are brought closer together, the first locking feature 324 can abut against a corresponding beveled surface 328 on the second end body 318. The slope / curvature of the beveled surface 328 can bend / deflect the first locking feature 324 outward (e.g., away from the second end body 318). After passing along the beveled surface 328, the first locking feature 324 can return to its original (e.g., unbent and / or undeflected) state in which the first locking feature 324 is positioned to contact the corresponding second locking feature 326. In this position, the first and second locking features 324, 326 may inhibit or prevent the device 310 from transitioning from the second state 210b to the intermediate state 413 and / or the first state 211a.

[0033] In some embodiments, the interaction of one first locking feature 324 and one second locking feature 326 is sufficient to inhibit or prevent the device 310 from transitioning from the second state 211b to the intermediate state 4131 and / or the first state 211a. In other embodiments, multiple first and second locking features 324, 326 can be used to further inhibit or prevent the device 310 from transitioning away from the second state 211b. For example, with reference to FIG. 6H, the device 310 has two first locking features 324, e.g., positioned on opposite sides of the first end body 316 and / or configured to clip onto and / or clamp to corresponding opposite sides of the second end 318.

[0034] 61, in the second state 211b, the curved heads 366a of the third and fourth links 320c, 320d can be at least partially positioned within the detents 356a, 356b by moving the third and fourth links along the beveled surfaces 354a, 354b of the expansion slots 352a, 352b. Contact between the detents 356a, 356b and the curved heads 366a can further secure or lock the device in the second state 211b, e.g., before, during, and / or after engagement of the first and second locking features 324, 326. This can further inhibit or prevent the device from collapsing or otherwise transitioning away from the second state 211b after expansion / implantation.

[0035] 7A-7E are side views of respective instruments 710a-710e, each configured in accordance with embodiments of the present technology. Each of instruments 710a-710e can be at least approximately the same or identical in structure and / or function as instrument 310. Referring together to FIGS. 7A-7E, the dimensions of one or more aspects of the instruments described herein can be customized based, at least in part, on the patient's anatomy, e.g., the size of the intervertebral space IS (FIGS. 1-2B). For example, each of instruments 710a-710e has respective upper and lower supports 712a-712e, 714a-714e with respective heights H1-H5, each subsequent height being greater than the previous height (e.g., H2>H1, H3>H2, etc.). Additionally or alternatively, each of instruments 710a-710e can have one or more tapered or beveled leading edge portions 770, 772. For example, with reference to FIGURE 7C, the upper and lower supports 712c, 714c of device 710c have tapered leading edge portions 772a positioned near first end body 716. The slope / curvature of tapered leading edge portions 772a can be configured to create a generally smooth transition between first end body 716 of device 710c and the upper and lower supports 712c, 714c, for example, to reduce resistance to positioning device 710c into intervertebral space IS. As another example, with reference to FIGURE 7D, first end body 716 has tapered leading edge portions 772 configured to create a generally smooth transition between first end body 716 and the upper and lower supports 712c, 714c of device 710d. As another example, referring to Figure 7E, the first end body 716 has a tapered leading edge portion 772, and the upper and lower supports 712e, 714e of the device 710e have tapered leading edge portions 770b, 772 (Figure 7E). Both tapered leading edge portions 772b, 772 can be configured to create a generally smooth transition between the first end body 716 and the upper and lower supports 712e, 714e.The height H5 of the upper and lower supports 712e, 714e of the device 710e may be greater than the height H3 of the upper and lower supports 712c, 714c of the device 710c (FIG. 7C), and the tapered leading edge portion 770b of the device 710e may be different (e.g., longer) than the tapered leading edge portion 770a of the device.

[0036] 8A-10B are diagrams of another intervertebral device 810 ("device 810") configured in accordance with embodiments of the present technology. Specifically, FIGS. 8A and 8B are perspective and side views of device 810 in a first state 811a, FIGS. 9A and 9B are perspective and side views of device 810 in an intermediate state 813, and FIGS. 10A and 10B are perspective and side views of device 810 in a second state 812b. At least some aspects of device 810 may be generally the same or identical in structure and / or function to one or more of devices 210, 310, 710a-710e described herein above (e.g., FIGS. 2A-7E). Accordingly, like names and / or reference numbers (e.g., first end body 316 versus first end body 816) are used to indicate substantially the same or identical aspects. Additionally, with reference to Figures 8A and 8B, alignment pegs 836a, 836b of device 810 may be curved and configured to assist in expanding device 810 into a curved state, as described in further detail herein (e.g., with reference to Figures 10A and 10B).

[0037] 8A-9B together, moving the first end body 316 and the second end body 318 of the device 810 inward and / or toward one another can transition the device 810 from the first state 811a (FIGS. 8A and 8B) toward and / or to the intermediate state 813 (FIGS. 9A and 9B), as described above herein (e.g., with reference to FIGS. 6A-6F). This movement of the first and second end bodies 316, 318 can cause corresponding movement of the expansion assemblies 822a, 822b (e.g., upper and / or lower supports 812, 814), as described above herein (e.g., with reference to FIGS. 6A-6F).

[0038] 9A-10B together, moving first end body 316 and second end body 318 closer together can move device 810 from intermediate state 813 (FIGS. 9A and 9B) toward and / or to second state 811b (FIGS. 10A and 10B), as described above herein (e.g., with reference to FIGS. 6D-6I). This movement of first and second end bodies 316, 318 can cause corresponding movement of extension assemblies 822a, 822b, for example, moving respective ones of upper and lower supports 812, 814 away from one another, as described above herein (e.g., with reference to FIGS. 6D-6I).

[0039] 10A and 10B, in the second state 811b, one or more of the supports 812, 814 may be angled, for example, with respect to the longitudinal axis X of the device 810. In the illustrated embodiment, for example, the first upper support 812a forms a first angle A1 with respect to the longitudinal axis X, and the first lower support 814a forms a second angle A2 with respect to the longitudinal axis X. The second angle A2 may be greater than, less than, or equal to the first angle A1. The first angle A1 and / or the second angle A2 may be between about 1° and about 30°, e.g., at least 1°, at least 2°, at least 3°, at least 4°, at least 5°, at least 6°, at least 7°, at least 8°, at least 9°, at least 10°, at least 15°, at least 20°, at least 25°, any angle therebetween, or another suitable angle. In at least some embodiments, first angle A1 and / or second angle A2 may be selected based at least in part on the curvature of the patient's spine (S), for example, to provide a desired lordotic correction when instrument 810 is positioned between first vertebral body V1 and vertebral body V2 (FIG. 1). In the illustrated embodiment, all of supports 812, 814 are configured to angle when instrument 810 is in second state 811b, although in other embodiments, only a subset of supports 812, 814 (e.g., upper supports 812a, 812b or lower supports 814a, 814b) are configured to angle when instrument 810 is in second state 811b.

[0040] 9B, the expansion slots 852a, 852b of the upper and / or lower supports 812, 814 may be configured to create angled expansion of the device 810. For example, as best shown in FIG. 9B, a first expansion slot 812a and / or a first beveled surface 854a may have a different configuration (e.g., be positioned closer to the longitudinal axis X, have a greater slope or angle, etc.) than a second expansion slot 812b and / or a second beveled surface 854b. Thus, when the first link 320a is driven along the first beveled surface 854a, it can cause a greater amount of movement than would be caused by driving the second link 320b along the second beveled surface 854b, thereby causing an angled vertical / lordotic expansion of the first upper and lower supports 812, 814 (and / or one or more of the other supports 812, 814). As described above herein (e.g., with reference to FIGS. 3M-3O and 6I) and shown in FIG. 10B, each of the links 320 can engage a corresponding expansion slot 852 via a rounded link head 366. Thus, even though the first and second expansion slots 852a, 852b may have different configurations from one another, the rounded link head 366 of the link 320 is expected to provide improved contact and / or engagement with both the first and second expansion slots 812a, 812b during angled vertical / lordotic expansion, thereby improving the fatigue resistance of the device 310 and / or improving the overall durability of the device.

[0041] 11A-13D are diagrams of an instrument 810 and an implantable instrument delivery tool 1180 ("delivery tool 1180") configured in accordance with embodiments of the present technology. More specifically, FIGS. 11A-11C are perspective and cross-sectional views of instrument 810 and delivery tool 1180 when instrument 810 is in a first state 811a, FIGS. 12A-12C are perspective and cross-sectional views of instrument 810 and delivery tool 1180 when instrument 810 is in a second state 811b, and FIGS. 13A-13D are perspective and cross-sectional views of instrument 810 and delivery tool 1180 after actuation of the delivery tool to move instrument 810 toward intermediate state 813. While FIGS. 11A-13D illustrate instrument 810, one skilled in the art will understand that delivery tool 1180 may also be configured for use with instrument 310 of FIGS. 3A-6I or another suitable intervertebral device.

[0042] 11A, the delivery tool 1180 can include an insertion shaft 1182 with an instrument receiving portion 1184 configured to releasably receive the second end body 318 of the instrument 810. Together, the delivery tool 1180 and the instrument 810 can comprise a spinal system 1181 configured to treat the spine of a patient. With reference to FIG. 11B, the delivery tool 1180 can further include a first coupling shaft 1186 configured to be at least partially positioned within and / or coupled to (e.g., threadably coupled to) the first mounting opening 332 of the first end body 316, and a second coupling shaft 1188 configured to be at least partially positioned within and / or coupled to (e.g., threadably coupled to) the second mounting opening 334 of the second end body 318. The first coupling shaft 1186 is movably positionable within the second coupling shaft 1188, and both the first and second coupling shafts 1186, 1188 are movably positionable within the insertion shaft 1182. Referring to FIG. 11C, the second coupling shaft 1188 can have a notch 1190 configured to contact a stop tab or feature 1194 of an insertion limiter 1192. When the notch 1190 contacts the stop tab 1184, the insertion limiter 1192 can be configured to arrest or prevent movement of the second coupling shaft 1188, for example, distally and / or toward the first end body 316 (FIG. 11B).

[0043] 12A, the delivery tool 1180 is used to transition the instrument 810 to the second state 811b. For example, with reference to FIG. 12B, one or both of the first and second coupling shafts 1186, 1188 can be moved relative to one another to cause corresponding movement of the first end body 316 and the second end body 318 toward one another, thereby expanding the instrument 810 as described above herein (e.g., with reference to FIGS. 6A-6I and 8A-10B). As best seen in FIG. 12B, upon coupling the second coupling shaft 1188 to the second attachment port 334 of the second end body 318, at least a portion of the threads 1196 can extend outwardly through the gap 356 defined by the second attachment port 334 (see, e.g., FIG. 3I). Referring to FIG. 12C, movement of the first and second coupling shafts 1186, 1188 can couple the first and second locking features 324, 326 to one another as described above herein (e.g., with reference to FIGS. 5A-5D and 6A-6I).

[0044] 13A , the insertion limiter 1192 of the delivery tool 1180 has been actuated (e.g., depressed) to transition the instrument 810 to the intermediate state 1113. With reference to FIG. 13B , actuation of the insertion limiter 1192 can move the stop tab 1194 out of contact with the notch 1190 of the second coupling shaft 1188, thereby permitting further movement of the second coupling shaft 1188. For example, with reference to FIGS. 13C and 13D , which additionally show selected views of the instrument 810 with other views (e.g., upper and lower supports) omitted for clarity, after actuation of the insertion limiter 1192, the second coupling shaft 1188 can be further advanced toward (e.g., towards) the first end body 316. This movement of the second coupling shaft 1188 may cause the second coupling shaft 1188 to contact the first locking feature 324, thereby decoupling the first locking feature 324 and the second locking feature 326. In the illustrated embodiment, for example, the second coupling shaft 1188 may cause the first locking feature 324 to bend / deflect outward (e.g., away from the first and / or second coupling shafts 1186, 1188) and / or release from contact with the second locking feature 326, thereby moving the first and / or second end bodies 316, 318 relative to one another, thereby transitioning the device 810 away from the second state 811 b and, for example, toward and / or to the intermediate state 813 and / or the first state 811 a.

[0045] C. Implementation The present technology is described according to various aspects, for example, as described below. Various embodiments of aspects of the present technology are described as numbered embodiment terms (1, 2, 3, etc.) for convenience. These are provided by way of example and not by way of limitation of the present technology. It should be noted that any of the dependent embodiment terms can be combined in any suitable manner and can form their own independent embodiment terms. Other embodiment terms can be provided in a similar manner. [Embodiment 1] 1. An intervertebral spacer comprising: a first expansion assembly including a first upper support and a first lower support; a second expansion assembly including a second upper support and a second lower support; a first end body coupled to the first expansion assembly and the second expansion assembly, the end body having a first locking feature; an intervertebral spacer comprising: a second end body coupled to the first expansion assembly and the second expansion assembly, the second end body having a locking region configured to receive the first locking feature when the first expansion assembly and the second expansion assembly are separated and expanded, thereby moving the intervertebral spacer from an unexpanded state to an expanded state, and the first locking feature engaging the locking region to maintain the intervertebral spacer in the expanded state. [Embodiment 2] 2. The intervertebral spacer of claim 1, wherein the first locking feature comprises a hooked region and the second locking feature comprises a notch, the hooked region being positioned to contact the notch when the intervertebral spacer is in the expanded state. [Embodiment 3] 3. The intervertebral spacer of claim 1 or 2, wherein the second end body further comprises a beveled surface configured to deflect the first locking feature outward from the second end body when the intervertebral spacer is moved from the unexpanded state to the expanded state. [Embodiment 4] The intervertebral spacer of any one of embodiments 1 to 3, wherein the first locking feature is a first upper locking feature configured to couple to a first side of the second end body, and the first end body further comprises a first lower locking feature configured to couple to a side of the second end body opposite the first side when the intervertebral spacer is in the expanded state. [Embodiment 5] In the non-expanded state, the first expansion assembly and the second expansion assembly are positioned at least partially between the first end body and the second end body; the first locking feature is spaced from the second locking feature; In the expanded state, the first end body and the second end body are positioned at least partially between the first expansion assembly and the second expansion assembly; 5. The intervertebral spacer of any one of claims 1 to 4, wherein the first locking feature is coupled to the second locking feature to at least partially prevent the intervertebral spacer from returning to the unexpanded state. [Embodiment 6] An intervertebral spacer according to any one of embodiments 1 to 5, wherein in the expanded state, the first upper support and the first lower support are spaced apart from each other, and the second upper support and the second lower support are spaced apart from each other. [Embodiment 7] The intervertebral spacer according to any one of embodiments 1 to 6, wherein in the second state, the first upper support, the first lower support, the second upper support, and / or the second lower support are angled relative to the longitudinal axis of the intervertebral spacer. [Embodiment 8] The intervertebral spacer of any one of embodiments 1 to 7, wherein in the unexpanded state, the first locking feature is positioned at least partially between the first expansion assembly and the second expansion assembly. [Embodiment Item 9] 9. The intervertebral spacer of embodiment 8, wherein the first upper support, the first lower support, the second upper support, and / or the second lower support have a recessed portion defining a locking feature gap into which at least a portion of the first locking feature is located when the intervertebral spacer is in the unexpanded state. [Embodiment 10] further comprising a plurality of links configured to couple the first and second expansion assemblies to the first and second end bodies; Each of the links has a rounded link head; The intervertebral spacer of any one of embodiments 1 to 9, wherein the first upper support, the first lower support, the second upper support, and / or the second lower support have an expansion slot with a detent configured to receive the rounded link head when the intervertebral spacer is in the expanded state. [Embodiment 11] 11. The intervertebral spacer of claim 10, wherein at least one of the plurality of links has an alignment slot configured to correspond and mate with a link locking feature of the first or second end body to at least partially prevent rotational movement of the at least one link relative to the first or second end body. [Embodiment 12] An intervertebral spacer according to any one of embodiments 1 to 11, characterized in that the first end body and / or the second end body have alignment tabs, the first expansion assembly and / or the second expansion assembly include alignment slots, and the alignment tabs are at least partially positioned within the alignment slots when the intervertebral spacer is in the expanded state. [Embodiment 13] 13. The intervertebral spacer of claim 12, wherein the alignment slot is configured to at least partially prevent inward horizontal movement of one or more of the upper and lower supports when the alignment tab is at least partially positioned within the alignment slot. [Embodiment 14] An intervertebral spacer described in any one of embodiments 1 to 13, characterized in that the first expansion assembly and the second expansion assembly are mechanically connected to sequentially expand the intervertebral spacer in different directions. [Embodiment 15] 15. The intervertebral spacer of any one of claims 1 to 14, wherein the first locking feature is configured to fasten to the locking region. [Embodiment 16] 16. The intervertebral spacer according to any one of claims 1 to 15, wherein the first locking feature comprises a barbed locking arm. [Embodiment 17] 1. A method of implanting an intervertebral spacer between a first vertebral body and a second vertebral body in a patient's spinal column, the method comprising: inserting the intervertebral spacer between the first vertebral body and the second vertebral body; transitioning the intervertebral spacer from an unexpanded state toward an expanded state, wherein the step of transitioning the intervertebral spacer from the unexpanded state toward the expanded state includes: moving a first end body of the intervertebral spacer toward a second end body of the intervertebral spacer; moving a first expansion assembly of the intervertebral spacer and a second expansion assembly of the intervertebral spacer radially outward relative to a longitudinal axis of the intervertebral spacer; and engaging a first locking feature of the first end body with a second locking feature of the second end body to at least partially prevent the intervertebral spacer from returning toward the first condition. [Embodiment 18] The method of embodiment 17, wherein the step of moving the first assembly of the intervertebral spacer and the second expansion assembly of the intervertebral spacer radially outward relative to the longitudinal axis includes moving the first expansion assembly and the second expansion assembly away from each other to horizontally expand the intervertebral spacer. [Embodiment 19] moving a first upper support and a first lower support of the first expansion assembly away from each other; 19. The method of claim 17 or 18, further comprising the step of causing vertical expansion of the intervertebral spacer by moving the second upper support and the second lower support of the second expansion assembly away from each other. [Embodiment 20] 20. The method of claim 19, wherein the step of causing the vertical expansion of the intervertebral spacer comprises causing the vertical expansion after causing the horizontal expansion of the intervertebral spacer. [Embodiment 21] 21. The method of any one of claims 17-20, wherein engaging the first locking feature of the first end body with the second locking feature of the second end body includes causing a beveled surface of the second end body to bend the locking feature outwardly and away from the second end body. [Embodiment 22] 22. The method of any one of claims 17-21, wherein the first locking feature is a first upper locking feature, and wherein engaging the first upper locking feature with the second locking feature includes positioning at least a portion of the second end body between the first upper locking feature and a first lower locking feature of the first end body. [Embodiment 23] 23. The method of embodiment 22, wherein the first upper locking feature and the first lower locking feature are positioned on opposite sides of the first end body. [Embodiment 24] 1. A spinal system for treating a patient's spine, the spinal system comprising: an intervertebral spacer configured to be positioned between a first vertebral body and a second vertebral body of the patient's spinal column, the intervertebral spacer comprising: a first end body having a first locking feature; a second end body having a second locking region configured to receive the first locking feature to move the intervertebral spacer from an unexpanded state to an expanded state, and the first locking feature mates with the second locking region to maintain the intervertebral spacer in the expanded state; a delivery tool operably coupleable to the intervertebral spacer and configured to transition the intervertebral spacer between the unexpanded state and the expanded state, the delivery tool comprising: a first engagement shaft configured to releasably couple the first end body of the intervertebral spacer to the delivery tool; a second engagement shaft configured to releasably couple the second end body of the intervertebral spacer to the delivery tool, the second engagement shaft having a notch; 1. A spinal column system comprising: an insertion limiter having a stop tab and movable between (i) a first position in which the stop tab contacts the notch to at least partially prevent further movement of the second engagement shaft toward the first locking feature of the intervertebral spacer; and (ii) a second position in which the stop tab is spaced from the notch to allow movement of the second engagement shaft toward the first expansion locking feature. [Embodiment 25] 25. The spinal system of claim 24, wherein in the expanded state, movement of the second engagement shaft toward the first expansion locking feature disengages the first locking feature from the second locking feature and moves the intervertebral spacer toward the first state. [Embodiment 26] 26. The spinal system of claim 24 or 25, wherein the second engagement shaft is configured to bend the first locking feature away from the second locking feature, thereby decoupling the first end body from the second end body. [Embodiment 27] 27. The spinal system of embodiment 26, wherein the second end body has a threaded attachment port configured to threadably receive the threads of the second engagement shaft, the threaded attachment port defining a gap such that a portion of the threads extends radially outward from the threaded attachment port, the portion of the threads configured to bend the first locking feature away from the second locking feature, thereby decoupling the first end body from the second end body. [Embodiment 28] 1. An intervertebral spacer comprising: a first expansion assembly configured to contact a vertebral body of the patient, the first expansion assembly including a first upper support and a first lower support; a second expansion assembly configured to contact the vertebral body, the second expansion assembly including a second upper support and a second lower support; a first clamp linkage assembly rotatably coupled to the first expansion assembly and the second expansion assembly, the first clamp linkage assembly including a pair of locking arms; an intervertebral spacer comprising: a second linkage assembly rotatably coupled to the first expansion assembly and the second expansion assembly; and the second linkage assembly configured to push the pair of locking arms apart when the intervertebral spacer is moved toward an expanded state, such that the pair of locking arms lock onto the second expansion assembly to maintain the intervertebral spacer in the expanded state. [Embodiment 29] 29. The intervertebral spacer of claim 28, wherein each of the pair of locking arms has a hooked region positioned to contact the second linkage assembly when the intervertebral spacer is in the expanded state. [Embodiment 30] The intervertebral spacer of embodiment 28 or 29, wherein the second linkage assembly further comprises a sloped surface configured to bias the pair of locking arms outward when the intervertebral spacer is moved toward the expanded state. [Embodiment 31] The intervertebral spacer according to any one of embodiments 28 to 30, wherein the first clamp linkage assembly includes a pair of pivots. [Embodiment 32] An intervertebral spacer according to any one of embodiments 28 to 31, characterized in that the first expansion assembly and the second expansion assembly are mechanically linked to sequentially expand the intervertebral spacer in different directions. [Embodiment 33] An intervertebral spacer according to any one of embodiments 28 to 32, characterized in that the locking arms are configured to bias outward and then inward to fasten to the second expansion assembly. [Embodiment 34] An intervertebral spacer according to any one of claims 28 to 33, wherein one or both of the locking arms has a barbed end portion. [Embodiment 35] An intervertebral spacer according to any one of embodiments 28 to 34, wherein at least one of the locking arms has a first locking feature including a hooked region, and the second expansion assembly has a second locking feature including a notch, and the hooked region is positioned to contact the notch when the intervertebral spacer is in the locked state. [Embodiment 36] An intervertebral spacer according to any one of embodiments 28 to 25, wherein the second linkage assembly includes a sloped surface configured to push the pair of locking arms apart. [Embodiment 37] An intervertebral spacer according to any one of embodiments 28 to 36, characterized in that the pair of locking arms are positioned on opposite sides of the second linkage assembly when the pair of locking arms hold the intervertebral spacer in an expanded state. [Embodiment 38] An intervertebral spacer according to any one of embodiments 28 to 37, wherein in the expanded state, the first upper support and the first lower support are spaced apart from each other, and the second upper support and the second lower support are spaced apart from each other. [Embodiment 39] An intervertebral spacer according to any one of embodiments 28 to 38, wherein in the second state, the first upper support, the first lower support, the second upper support, and / or the second lower support are angled relative to the longitudinal axis of the intervertebral spacer. [Embodiment 40] An intervertebral spacer according to any one of embodiments 28 to 39, wherein the first locking feature of the second linkage assembly is positioned at least partially between the first expansion assembly and the second expansion assembly when the intervertebral spacer is in an unexpanded state. [Embodiment 41] 41. The intervertebral spacer of embodiment 40, wherein the second linkage assembly includes a recessed portion defining a locking feature gap into which at least a portion of one of the locking arms is positioned when the intervertebral spacer is in the unexpanded state. [Embodiment 42] further comprising a plurality of links configured to couple the first and second expansion assemblies to the first and second end bodies; Each of the links has a rounded link head; An intervertebral spacer according to any one of embodiments 28 to 41, characterized in that the first upper support, the first lower support, the second upper support, and / or the second lower support have an expansion slot with a detent configured to receive the rounded link head when the intervertebral spacer is in the expanded state. [Embodiment 43] 43. The intervertebral spacer of embodiment 42, wherein at least one of the plurality of links has an alignment slot configured to mate with a link locking feature of the first or second end body to at least partially prevent rotational movement of the at least one link relative to the first or second end body. [Embodiment 44] An intervertebral spacer according to any one of embodiments 38 to 43, further comprising an alignment tab, wherein the first expansion assembly and / or the second expansion assembly includes an alignment slot, and wherein the alignment tab is at least partially positioned within the alignment slot when the intervertebral spacer is in the expanded state. [Embodiment 45] 45. The intervertebral spacer of embodiment 44, wherein the alignment slot is configured to at least partially prevent inward horizontal movement of one or more of the upper and lower supports when the alignment tab is at least partially positioned within the alignment slot.

[0046] D. conclusion Any of the disclosed medical devices, instruments, or components thereof can be constructed from a wide variety of materials, including any bioabsorbable, biologically compatible, or compatible material. Materials considered acceptable for biological implantation include stainless steel, titanium, tantalum, several metal alloys, various plastics, polymers, resins, bioabsorbable materials, and the like. Any assembly or components thereof can also be constructed, in whole or in part, from a shape-memory or other deformable material. As will be readily understood, the components of the present invention, as generally described and illustrated herein above, can be arranged and designed in a wide variety of configurations. Thus, the detailed descriptions of the device, system, and method embodiments, such as those depicted in Figures 1-13D, are not intended to limit the scope of the invention as claimed in this application or any other priority application related thereto, but are merely illustrative of exemplary embodiments of the invention.

[0047] Instruments, implants, devices, methods, and related technology are disclosed in U.S. Patent Nos. 10,105,238, 10,898,340, 6,648,917, 6,562,074, 6,852,129, 6,863,673, 8,628,576, 9,308,099, 10,201,431, 10,945,859, and 9,820,788. , U.S. Patent No. 10,105,238, U.S. Patent Application No. 16,565,403, U.S. Patent Application No. 16,687,520, U.S. Patent Application No. 17,125,633, U.S. Patent Application No. 15,793,950, U.S. Patent Application No. 16,394,244, U.S. Patent Application No. 15,970,212, U.S. Patent Application No. 15,500,969, U.S. Patent Application No. 18,335,737, U.S. Patent Application No. 18,464,949, U.S. Patent Application No. 18,470,1 No. 40, U.S. Patent Application No. 18,073,364, U.S. Provisional Patent Application No. 63 / 169,799, U.S. Provisional Patent Application No. 63 / 163,489, U.S. Provisional Patent Application No. 63 / 163,521, U.S. Provisional Patent Application No. 63 / 169,804, U.S. Provisional Patent Application No. 63 / 163,536, U.S. Provisional Patent Application No. 61 / 442,482, U.S. Provisional Patent Application No. 63 / 488,757, U.S. Provisional Patent Application No. 63 / 611,913, U.S. Provisional Patent Application No. 63 / 611,888 Nos. 63 / 504,248, 63 / 611,874, 63 / 550,554, International Application Nos. PCT / US20 / 49920, PCT / US21 / 63881, PCT / US22 / 19706, PCT / US23 / 81937, and PCT / US22 / 19706, the entire contents of which are incorporated herein by reference.These technologies can be used in conjunction with, incorporate, and / or combine with the systems, methods, features, and components disclosed herein. For example, the implants disclosed herein may include features, such as locking screws, connectors, and the like, disclosed in patent applications, patent application publications, and patents that are subject to the "incorporated by reference" practice under U.S. patent law. The implants can be used with tools, instruments, guides (e.g., incision guides, placement guides, and the like), holders (e.g., multi-portal cannula holders, triangulation holders, instrument holders, rotating instrument holders, and the like), delivery devices, and the like. All patent applications, patent publications, and patents cited herein are hereby incorporated by reference and incorporated herein in their entireties. Various features of the embodiments disclosed herein can be mixed and matched with one another to provide additional configurations within the scope of the present invention. By way of non-limiting example, the features and enhanced capabilities of the embodiments disclosed herein can be combined to provide symmetric spacer embodiments that do not provide lordotic correction, symmetric spacer embodiments that provide lordotic correction, asymmetric spacer embodiments that do not provide lordotic correction, and asymmetric spacer embodiments that provide lordotic correction. One or more embodiments can be implanted together, thereby providing the precise support and / or correction needed to restore sagittal alignment and balance.

[0048] As used herein, the terms "coupled to," "bonded to," and "in communication with" refer to any form of interaction between two or more elements, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interactions. Two components may be functionally coupled to one another even if they are not in direct contact with one another. The term "abut" refers to items that are in direct physical contact with one another, although such items may not necessarily be attached to one another.

[0049] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein that is described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While various aspects of the embodiments are illustrated in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0050] The terms "upper" and "lower," "top" and "bottom," "front" and "rear" are used herein as relative terms for ease of description and understanding. It will be appreciated that in embodiments of the present invention, the upper and lower, top and bottom, and / or front and rear elements may be reversed.

[0051] Any method disclosed herein includes one or more steps or acts of performing the described method. Method steps and / or acts may be interchangeable. In other words, if a specific order of steps or acts is not necessary for the proper operation of an embodiment, the order and / or use of specific steps and / or acts may be modified. To the extent that any content incorporated by reference herein conflicts with the present invention, the present invention controls.

[0052] References throughout this specification to an "embodiment" or "the (above) embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of quoted phrases or variations thereof throughout this specification do not necessarily all refer to the same embodiment.

[0053] It should also be understood that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, a single figure, or the description thereof to simplify understanding of the disclosure. However, this method of disclosure should not be interpreted as reflecting an intention that any claim in this application, or any application claiming priority to this application, requires more features than are expressly recited in that claim. Instead, as the following claims reflect, aspects of the invention lie in combinations of fewer than all features of any single above-disclosed embodiment. Thus, the appended claims following this specification are expressly incorporated herein, with each claim standing on its own as a separate embodiment. The present disclosure includes all permutations of independent claims, including those dependent claims.

[0054] The use of the term "first" in a claim with respect to a feature or element does not necessarily imply the presence of a second or additional such feature or element. Elements described in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112, paragraph 6. Those skilled in the art will recognize that changes can be made to the details of the above-described embodiments without departing from the underlying principles of the invention.

[0055] While particular embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise forms and components disclosed herein. Various modifications, changes, and variations apparent to those skilled in the art can be made in the arrangement, operation, and details of the methods and systems of the present invention disclosed herein without departing from the spirit and scope of the invention.

Claims

1. 1. An intervertebral spacer comprising: a first expansion assembly including a first upper support and a first lower support; a second expansion assembly including a second upper support and a second lower support; a first end body coupled to the first expansion assembly and the second expansion assembly, the first end body having a first locking feature; an intervertebral spacer including a second end body coupled to the first expansion assembly and the second expansion assembly, the second end body having a locking region configured to receive the first locking feature when the first expansion assembly and the second expansion assembly are separated and expanded, thereby moving the intervertebral spacer from a non-expanded state to an expanded state, and the first locking feature coupled to the locking region to maintain the intervertebral spacer in the expanded state.

2. 2. The intervertebral spacer of claim 1, wherein the first locking feature includes a hooked region and the second locking feature includes a notch, the hooked region positioned to contact the notch when the intervertebral spacer is in the expanded state.

3. 2. The intervertebral spacer of claim 1, wherein the second end body further comprises a beveled surface configured to deflect the first locking feature outward from the second end body when the intervertebral spacer is moved from the unexpanded state to the expanded state.

4. 2. The intervertebral spacer of claim 1, wherein the first locking feature is a first upper locking feature configured to couple to a first side of the second end body, and the first end body further includes a first lower locking feature configured to couple to a side of the second end body opposite the first side when the intervertebral spacer is in the expanded state.

5. In the unexpanded state: the first expansion assembly and the second expansion assembly are positioned at least partially between the first end body and the second end body; the first locking feature is spaced from the second locking feature; In the expanded state, the first end body and the second end body are positioned at least partially between the first expansion assembly and the second expansion assembly; The intervertebral spacer of claim 1 , wherein the first locking feature is coupled to the second locking feature to at least partially prevent the intervertebral spacer from returning to the unexpanded state.

6. 2. The intervertebral spacer of claim 1, wherein in the expanded state, the first upper support and the first lower support are spaced apart from one another and the second upper support and the second lower support are spaced apart from one another.

7. 2. The intervertebral spacer of claim 1, wherein in the second state, the first upper support, the first lower support, the second upper support, and / or the second lower support are angled relative to a longitudinal axis of the intervertebral spacer.

8. The intervertebral spacer of claim 1 , wherein in the unexpanded state, the first locking feature is positioned at least partially between the first expansion assembly and the second expansion assembly.

9. 9. The intervertebral spacer of claim 8, wherein the first upper support, the first lower support, the second upper support, and / or the second lower support have a recessed portion defining a locking feature gap into which at least a portion of the first locking feature is located when the intervertebral spacer is in the unexpanded state.

10. further comprising a plurality of links configured to couple the first and second expansion assemblies to the first and second end bodies; Each of the links has a rounded link head; 2. The intervertebral spacer of claim 1, wherein the first upper support, the first lower support, the second upper support, and / or the second lower support have expansion slots with detents configured to receive the rounded link heads when the intervertebral spacer is in the expanded state.

11. 11. The intervertebral spacer of claim 10, wherein at least one of the plurality of links has an alignment slot configured to mate with a link locking feature of the first or second end body to at least partially prevent rotational movement of the at least one link relative to the first or second end body.

12. 2. The intervertebral spacer of claim 1, wherein the first end body and / or the second end body have alignment tabs, and the first expansion assembly and / or the second expansion assembly include alignment slots, and the alignment tabs are at least partially positioned within the alignment slots when the intervertebral spacer is in the expanded state.

13. 13. The intervertebral spacer of claim 12, wherein the alignment slot is configured to at least partially prevent inward horizontal movement of one or more of the upper support and the lower support when the alignment tab is at least partially positioned within the alignment slot.

14. The intervertebral spacer of claim 1 , wherein the first expansion assembly and the second expansion assembly are mechanically coupled to sequentially expand the intervertebral spacer in different directions.

15. The intervertebral spacer of claim 1 , wherein the first locking feature is configured to fasten to the locking region.

16. The intervertebral spacer of claim 1 , wherein the first locking feature comprises a barbed locking arm.

17. 1. A method of implanting an intervertebral spacer between a first vertebral body and a second vertebral body in a patient's spinal column, the method comprising: inserting the intervertebral spacer between the first vertebral body and the second vertebral body; transitioning the intervertebral spacer from an unexpanded state toward an expanded state, wherein the step of transitioning the intervertebral spacer from the unexpanded state toward the expanded state includes: moving a first end body of the intervertebral spacer toward a second end body of the intervertebral spacer; moving the first expansion assembly of the intervertebral spacer and the second expansion assembly of the intervertebral spacer radially outward relative to a longitudinal axis of the intervertebral spacer; and engaging a first locking feature of the first end body with a second locking feature of the second end body to at least partially prevent the intervertebral spacer from returning toward a first condition.

18. 18. The method of claim 17, wherein the step of moving the first assembly of the intervertebral spacer and the second expansion assembly of the intervertebral spacer radially outward relative to the longitudinal axis includes moving the first expansion assembly and the second expansion assembly away from each other to horizontally expand the intervertebral spacer.

19. moving a first upper support and a first lower support of the first expansion assembly away from each other; 18. The method of claim 17, further comprising the step of causing vertical expansion of the intervertebral spacer by moving a second upper support and a second lower support of the second expansion assembly away from each other.

20. 20. The method of claim 19, wherein the step of causing the vertical expansion of the intervertebral spacer comprises causing a horizontal expansion of the intervertebral spacer followed by causing the vertical expansion.

21. 18. The method of claim 17, wherein the step of engaging the first locking feature of the first end body with the second locking feature of the second end body includes causing a beveled surface of the second end body to bend the locking feature outwardly and away from the second end body.

22. 18. The method of claim 17, wherein the first locking feature is a first upper locking feature, and wherein engaging the first upper locking feature with the second locking feature comprises positioning at least a portion of the second end body between the first upper locking feature and a first lower locking feature of the first end body.

23. 23. The method of claim 22, wherein the first upper locking feature and the first lower locking feature are positioned on opposite sides of the first end body.

24. 1. A spinal system for treating a patient's spine, the spinal system comprising: an intervertebral spacer configured to be positioned between a first vertebral body and a second vertebral body of the patient's spinal column, the intervertebral spacer comprising: a first end body having a first locking feature; a second end body having a second locking region configured to receive the first locking feature to move the intervertebral spacer from an unexpanded state to an expanded state, and the first locking feature mates with the second locking region to maintain the intervertebral spacer in the expanded state; a delivery tool operably connectable to the intervertebral spacer and configured to transition the intervertebral spacer between the unexpanded state and the expanded state, the delivery tool comprising: a first engagement shaft configured to releasably couple the first end body of the intervertebral spacer to the delivery tool; a second engagement shaft configured to releasably couple the second end body of the intervertebral spacer to the delivery tool, the second engagement shaft having a notch; 10. A spinal column system comprising an insertion limiter having a stop tab and movable between (i) a first position in which the stop tab contacts the notch to at least partially prevent further movement of the second engagement shaft toward the first locking feature of the intervertebral spacer, and (ii) a second position in which the stop tab is spaced from the notch to allow movement of the second engagement shaft toward the first expansion locking feature.

25. 25. The spinal system of claim 24, wherein in the expanded state, the movement of the second engagement shaft toward the first expansion locking feature disengages the first locking feature from the second locking feature and transitions the intervertebral spacer toward the first state.

26. 25. The spinal system of claim 24, wherein the second engagement shaft is configured to bend the first locking feature away from the second locking feature, thereby decoupling the first end body from the second end body.

27. 27. The spinal system of claim 26, wherein the second end body has a threaded attachment port configured to threadably receive the threads of the second engagement shaft, the threaded attachment port defining a gap such that a portion of the threads extends radially outward from the threaded attachment port, the portion of the threads configured to bend the first locking feature away from the second locking feature, thereby decoupling the first end body from the second end body.

28. 1. An intervertebral spacer comprising: a first expansion assembly configured to contact a vertebral body of a patient, the first expansion assembly including a first upper support and a first lower support; a second expansion assembly configured to contact the vertebral body, the second expansion assembly including a second upper support and a second lower support; a first clamp linkage assembly rotatably coupled to the first expansion assembly and the second expansion assembly, the first clamp linkage assembly including a pair of locking arms; an intervertebral spacer comprising: a second linkage assembly rotatably coupled to the first expansion assembly and the second expansion assembly, wherein the second linkage assembly is configured to push the pair of locking arms apart when the intervertebral spacer is moved toward an expanded state, so that the pair of locking arms lock onto the second expansion assembly to hold the intervertebral spacer in the expanded state.

29. 29. The intervertebral spacer of claim 28, wherein the pair of locking arms each include a hooked region positioned to contact the second linkage assembly when the intervertebral spacer is in the expanded state.

30. 29. The intervertebral spacer of claim 28, wherein the second linkage assembly further includes a beveled surface configured to bias the pair of locking arms outwardly when the intervertebral spacer is moved toward the expanded state.

31. 30. The intervertebral spacer of claim 28, wherein the first clamp linkage assembly includes twin pivots.

32. 30. The intervertebral spacer of claim 28, wherein the first expansion assembly and the second expansion assembly are mechanically coupled to sequentially expand the intervertebral spacer in different directions.

33. 29. The intervertebral spacer of claim 28, wherein the locking arms are configured to bias outwardly and then bias inwardly to clamp onto the second expansion assembly.

34. 30. The intervertebral spacer of claim 28, wherein one or both of the locking arms has a barbed end portion.

35. 29. The intervertebral spacer of claim 28, wherein at least one of the locking arms has a first locking feature including a hooked region and the second expansion assembly has a second locking feature including a notch, the hooked region positioned to contact the notch when the intervertebral spacer is in a locked state.

36. 30. The intervertebral spacer of claim 28, wherein the second linkage assembly includes a beveled surface configured to urge the pair of locking arms apart.

37. 30. The intervertebral spacer of claim 28, wherein the pair of locking arms are positioned on opposite sides of the second linkage assembly when the pair of locking arms hold the intervertebral spacer in an expanded state.

38. 30. The intervertebral spacer of claim 28, wherein in the expanded state, the first upper support and the first lower support are spaced apart from one another and the second upper support and the second lower support are spaced apart from one another.

39. 29. The intervertebral spacer of claim 28, wherein in the second condition, the first upper support, the first lower support, the second upper support, and / or the second lower support are angled relative to a longitudinal axis of the intervertebral spacer.

40. 29. The intervertebral spacer of claim 28, wherein the first locking feature of the second linkage assembly is positioned at least partially between the first expansion assembly and the second expansion assembly when the intervertebral spacer is in an unexpanded state.

41. 41. The intervertebral spacer of claim 40, wherein the second linkage assembly includes a recessed portion defining a locking feature gap into which at least a portion of one of the locking arms is received when the intervertebral spacer is in the unexpanded state.

42. further comprising a plurality of links configured to couple the first and second expansion assemblies to the first and second end bodies; Each of the links has a rounded link head; 29. The intervertebral spacer of claim 28, wherein the first upper support, the first lower support, the second upper support, and / or the second lower support have expansion slots with detents configured to receive the rounded link heads when the intervertebral spacer is in the expanded state.

43. 43. The intervertebral spacer of claim 42, wherein at least one of the plurality of links has an alignment slot configured to mate with a link locking feature of the first or second end body to at least partially prevent rotational movement of the at least one link relative to the first or second end body.

44. 39. The intervertebral spacer of claim 38, further comprising an alignment tab, wherein the first expansion assembly and / or the second expansion assembly includes an alignment slot, and the alignment tab is at least partially positioned within the alignment slot when the intervertebral spacer is in the expanded state.

45. 45. The intervertebral spacer of claim 44, wherein the alignment slot is configured to at least partially prevent inward horizontal movement of one or more of the upper support and the lower support when the alignment tab is at least partially positioned within the alignment slot.

Images