Expansion type fusion device with independent expansion system

Abstract

To provide an expansion spine fusion device, system and a method for using them.SOLUTION: An expansion spine fusion device is inserted into a patient in a state of passing through a small surgery path and being folded, is expanded in only a tail-head direction, in only a traverse direction, and in both of the directions, and in a desired case, after insertion, the device may be extended in these directions in a more independent state. The invention is useful in reducing risk and surgical complication, allowance of selection which is being executed in a desired width installation area, desired control in a height expansion through gradual tail-head direction expansion, and desired control in matching of adjacent vertebral bodies. The device, the system and the method are also used in providing control of a desired contact area which is desired between upper and lower vertebra end plates, and a device achieved by using, a mutual fitting end plate system.SELECTED DRAWING: Figure 5-6

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 62 / 637,306, filed March 1, 2018, which claims priority to U.S. Provisional Application No. 16 / 290,428, filed March 1, 2019, each of which is incorporated by reference in its entirety.

[0002] The teachings of the present application generally relate to medical devices and methods, including devices and methods for promoting intervertebral fusion, such as devices that can be inserted into a patient in a collapsed state through a small surgical channel and deployed in only the craniocaudal direction, only the transverse direction, or in both directions, with further independent extension in those directions after insertion, if desired. [Background technology]

[0003] The teachings provided herein include methods, devices, and systems for performing spinal implant procedures on a patient. Spinal fusion is typically employed to eliminate pain caused by movement of degenerated disc material. Upon successful fusion, the fusion device is permanently fixed within the disc space. A common procedure for addressing pain associated with degenerated discs due to various factors, such as trauma or aging, is the use of an intervertebral fusion device to fuse one or more adjacent vertebral bodies. Generally, to fuse adjacent vertebral bodies, the disc is first partially or completely removed. A fusion device is then generally inserted between the adjacent vertebrae to maintain normal disc spacing and restore spinal stability, thereby facilitating intervertebral fusion.

[0004] There are several conventional fusion devices and methods known in the art to achieve intervertebral fusion. These include screw rod configurations, solid bone implants, and fusion devices that typically include a cage or other implant mechanism filled with bone and / or bone growth inducers. These devices are implanted between adjacent vertebral bodies to fuse them together and relieve the associated pain.

[0005] However, there are challenges associated with known conventional fusion devices and methods. For example, current methods for placing conventional fusion devices may require that adjacent vertebral bodies be distracted to return a diseased disc space to its normal or healthy height prior to implantation of the fusion device. To maintain height once the fusion device is inserted, the fusion device is typically dimensioned to be taller than the initial distraction height. This height difference may make it difficult for a surgeon to place the fusion device in the distracted disc space. Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, there is a need for a fusion device that can be placed at a minimal, unobtrusive height within the intervertebral disc space and that can maintain the normal distance between adjacent vertebral bodies when implanted.

[0007] One of the most common postoperative complications for intervertebral fusion surgery is subsidence of the intervertebral graft or cage, which can be minimized or mitigated by using a larger footprint intervertebral cage or graft. This is often difficult to do, since to minimize the trauma and morbidity associated with spinal surgery, it is often advantageous to utilize the smallest surgical access possible to accomplish the surgical goal. Therefore, there is a need for a fusion device that can be inserted through a relatively small surgical passageway and then expanded to a larger footprint suitable for resisting subsidence.

[0008] It will be appreciated that spinal fusion is a procedure that can be used to eliminate pain, for example, which may be caused by movement of degenerated disc material. Upon successful fusion, the fusion device is permanently fixed in the disc space. Unfortunately, the devices and procedures used in the art still suffer from several problems, including those discussed above. For example, (i) reduced surgical complications and risk of device insertion through the use of minimal to very small intervertebral distraction, or perhaps no distraction, (ii) reduced surgical complications and risk of device insertion through small surgical channels, (iii) control of the desired width of device deployment through a single device variable transverse deployment system that provides on-the-fly selection of a desired footprint, a larger and possibly biased footprint to achieve a desired alignment or perhaps avoid device collapse during use, and (iv) increased safety through controllable decompression of neural elements through incremental control of the rate, amount, and pressure of deployment applied to surrounding tissue. Those skilled in the art will appreciate that the invention described herein addresses at least some of these problems, including: (v) desired control of height deployment through incremental cranio-caudal deployment of the device that gradually increases in a desired amount and rate via a drive system to achieve a desired intervertebral height; (vi) desired control over alignment of adjacent vertebral bodies through control provided by a design that provides the freedom to select any desired width of deployment, where that desired width is obtained independent of the incremental height control; and (vi) control of the desired contact area desired between the device and the upper and lower vertebral endplates, achieved, for example, using an interdigitating endplate system. [Means for solving the problem]

[0009] Expandable spinal fusion devices, systems, and methods for using the same are provided that can be inserted into a patient in a collapsed state through a small surgical channel and deployed in only the craniocaudal direction, only the transverse direction, or both, and can be further independently extended in these directions after insertion if desired. These inventions are beneficial in reducing risk and surgical complications, allowing on-the-fly selection of the desired width footprint, desired control of height deployment through incremental craniocaudal deployment, and desired control of alignment of adjacent vertebral bodies. The devices, systems, and methods also aid in providing desired control of the contact area between the device and the upper and lower vertebral endplates, achieved, for example, using an interdigitating endplate system.

[0010] In some embodiments, the expansion fusion device includes a first endplate, a second endplate, a third endplate, and a fourth endplate, two of which form an upper endplate assembly and two of which form a lower endplate assembly. The device can also include a craniocaudal deployment assembly configured to effect craniocaudal deployment between the upper endplate assembly and the lower endplate assembly. The device can also include a transverse deployment assembly configured to effect transverse deployment at the upper endplate assembly and the lower endplate assembly. In some embodiments, (a) a drive system having an actuator including a drive mechanism and a front and rear shaft, a wedge assembly coupled to the actuator, and a ramp assembly slidably coupled to the wedge assembly, wherein each of a first end plate, a second end plate, a third end plate, and a fourth end plate is slidably coupled to the ramp assembly; (b) a spacer system having at least a first spacer configured for insertion between a first pair of adjacent endplates selected from the group consisting of a first endplate, a second endplate, a third endplate, and a fourth endplate; A cranio-caudal deployment assembly is selected from one and a transverse deployment assembly is selected from the other.

[0011] It should be appreciated that the spacer system may have a single spacer or multiple spacers. In some embodiments, the spacer system may have any desired configuration, for example, as it may have a pair of spacers of equal or different widths and / or equal or different lengths. In some embodiments, a pair of spacers may be inserted alone or as part of a combined spacer unit. Such combined spacer units may be, for example, fork-like, and may be removable as a tool after establishing the desired space in vivo, or may be left in place in the patient as an implant during the procedure. Those skilled in the art will appreciate the versatility in selecting spacer sizes on the fly, for example, to achieve a desired width, as the amount of desired deployment may vary and change during the procedure. Those skilled in the art will also appreciate that deployment of the device using the drive system works independently of deployment of the device using the spacer system, providing increased versatility in the operating room.

[0012] In some embodiments, a pair of spacers are used, such that after insertion of the first spacer between the first pair of adjacent endplates, the spacer system includes a second spacer configured for insertion between the remaining pair of adjacent endplates, the remaining pair being selected from the group consisting of the first endplate, the second endplate, the third endplate, and the fourth endplate, and the second spacer being selected for a desired amount of deployment. Insertion of the second spacer may be independent of or simultaneous with insertion of the first spacer.

[0013] In some embodiments, the upper endplate assembly includes a first endplate and a second endplate, and the lower endplate assembly includes a third endplate and a fourth endplate. In such embodiments, the cranio-caudal deployment assembly can include a drive system, where the upper endplate assembly is slidably coupled to the ramp assembly, and the lower endplate assembly is slidably coupled to the ramp assembly, and the cranio-caudal deployment assembly is configured to effect cranio-caudal deployment between the upper and lower endplate assemblies upon activation of the actuator. And in some embodiments, the transverse deployment assembly includes a spacer system for transverse deployment, where a first spacer is configured for insertion between the third and fourth endplates, and a second spacer is configured for insertion between the third and fourth endplates.

[0014] It should be appreciated that the endplates are structural components of the device and that the device is designed to support the significant forces present in the intervertebral space of the patient. Thus, in some embodiments, the first, second, third and fourth endplates are each beams having an anterior-posterior axis and selected for their stiffness. However, it should be appreciated that in some embodiments, the design may be selected to provide some flexibility and therefore each of the first, second, third and fourth endplates may be selected for a desired amount of flexibility to match the vertebral endplates, for example, providing limited compliance to reduce point pressures on the vertebral endplates and reduce the risk of subsidence. It should be appreciated that in some embodiments, each of the first, second, third and fourth endplates may be designed to be rigid, flexible or a combination of rigidity and flexibility. In some embodiments, for example, each of the first endplate, second endplate, third endplate, and fourth endplate may be formed from a combination of materials, perhaps each designed with a first rigid material that provides rigid properties to maintain the linear configuration of the anterior-posterior axis of each beam, and a second flexible material that is sufficiently compliant on the beam surfaces that contact the vertebral endplates to conform to the vertebral endplates and provide limited compliance that may, for example, reduce point pressures on the vertebral endplates and reduce the risk of subsidence. Since each of the endplates may be designed with any one or any combination of these features, the set of endplates may have a great deal of flexibility in design. For example, the top endplate assembly may have a flexible surface in contact with the corresponding vertebral endplate, the bottom endplate assembly may have a rigid surface in contact with the corresponding vertebral endplate, and so on. Conversely, all of the endplates may have flexible contact surfaces or all of the endplates may have rigid contact surfaces. Additionally, the endplate sizes may be varied either alone or in combination.In some embodiments, at least one of the second endplate and the fourth endplate is larger than at least one of the first endplate and the third endplate.

[0015] The drive system can be used in devices for either vertical or horizontal deployment, alone or in combination with a spacer system, which can also be used in systems for either vertical or horizontal deployment. The actuator of the drive system is configured to have a distal end and a proximal end, at least a portion of the distal end encases a first screw mechanism and at least a portion of the proximal end includes a second screw mechanism, and the proximal end has a drive mechanism that can be configured to mount to a corresponding drive element of a drive instrument. The wedge assembly of the drive system provides a force to extend the device, and in some embodiments, the wedge assembly has a distal wedge and a proximal wedge. The ramp assembly redirects the force from the wedge assembly to the end plate, and in some embodiments, the ramp assembly has a first distal ramp, a second distal ramp, a first proximal ramp, and a second proximal ramp.

[0016] As one skilled in the art would like to inhibit or prevent the device from backing out of its deployed state in vivo, a deployment lock may be provided on the drive system and / or the spacer system. In some embodiments, the deployment lock includes a friction lock configured to lock by contact between the wedge assembly and the ramp assembly. And in some embodiments, depending on whether a single spacer or multiple spacers are used, the deployment lock includes a snap lock between the first spacer and the first adjacent endplate pair, between the second spacer and the remaining adjacent endplate pair, or both. In some embodiments, the actuator has a "neutral" position where the spacer system is free to deploy the device, and a "mated" position where the spacer system is locked and does not deploy or collapse. The mated position may be, for example, a friction lock or mating of complementary teeth, keys in slots, etc. Considering the measures presented herein, the deployment lock may also include some means for locking the first adjacent endplate pair, the remaining adjacent endplate pair, or both in place.

[0017] Methods of fusing an intervertebral space are also provided. In some aspects, a method of fusing an intervertebral space of a patient includes inserting a device taught herein into the intervertebral space of the patient with an inserter and performing craniocaudal and transverse deployment of the device by (i) actuation of a drive system and (ii) insertion of a spacer system into the device, where actuation and insertion are performed independently and in separate steps. One skilled in the art will appreciate that performing deployment using an actuated drive system is independent from deployment using a spacer system, providing much needed versatility and control in the operating room.

[0018] In some embodiments, the method includes loading the inserter into the device for insertion and driving the actuator with a drive element of the drive instrument, the drive element configured to mate with a drive feature of the actuator. In some embodiments, the actuator has a distal end and a proximal end, at least a portion of the distal end includes a first thread mechanism and at least a portion of the proximal end includes a second thread mechanism, the proximal end includes a drive mechanism, the drive mechanism configured to load onto a corresponding drive element of the drive instrument. In some embodiments, the method further includes loading the inserter into the device for insertion and driving the actuator with a drive element of the drive instrument, the drive element configured to mate with a drive feature of the actuator to rotate the actuator with the drive instrument.

[0019] In some aspects, a method of fusing an intervertebral space of a patient includes inserting a device taught herein into the intervertebral space of the patient and performing a transverse deployment using a spacer system, which includes inserting a first spacer into the device for a desired amount of deployment. In some aspects, the insertion of the first spacer is accompanied by the insertion of a second spacer into the device, which may occur sequentially or simultaneously. The method also includes performing a craniocaudal deployment using a drive system, which includes actuating the drive system on the device, where actuating and inserting the spacer are performed independently in separate steps in some aspects. Similarly, such a method further includes mounting an inserter to the device for insertion and driving an actuator with a drive element of the drive instrument, where the drive element is configured to mate with a drive mechanism of the actuator. In some aspects, the actuator has a distal end and a proximal end, where at least a portion of the distal end includes a first screw mechanism and at least a portion of the proximal end includes a second screw mechanism, where the proximal end includes a drive mechanism, where the drive mechanism is configured to mount to a corresponding drive element of the drive instrument. In such an aspect, the method further includes loading the insert into the apparatus for insertion and driving the actuator with a drive element of the drive device, the drive element configured to mate with a drive mechanism of the actuator to rotate the actuator with the drive device.

[0020] Devices that are extendable in length are also provided. In some aspects, the extendable length fusion device may include a first deployable device coupled to a second deployable device, a first actuator for extending the first deployable device and the second deployable device, and a second actuator configured to couple the first deployable device to the second deployable device. In some aspects, the first actuator is part of a drive system having a first wedge assembly for the first deployable device coupled to the first actuator, a first ramp assembly slidably coupled to the first wedge assembly, a second wedge assembly for the second deployable device coupled to the first actuator, and a second ramp assembly slidably coupled to the second wedge assembly. In some aspects, each of the first deployable device and the second deployable device includes a first end plate, a second end plate, a third end plate, and a fourth end plate, each end plate slidably coupled to a ramp assembly.

[0021] Similarly, devices are provided that deploy horizontally while significantly increasing the area of ​​contact with the vertebral endplates. In some aspects, the horizontally deploying fusion device can include an upper endplate assembly having a first endplate with a first plurality of protrusions, a second endplate with a second plurality of protrusions, and a lower endplate assembly having a third endplate with a third plurality of protrusions, and a fourth endplate with a fourth plurality of protrusions. In some embodiments, the first plurality of protrusions interdigitate with the second plurality of protrusions to expand and contract during horizontal deployment to significantly increase a surface area for contact with a superior vertebral endplate at the intervertebral space, the third plurality of protrusions interdigitate with the fourth plurality of protrusions to expand and contract during horizontal deployment to significantly increase a surface area for contact with a inferior vertebral endplate at the intervertebral space, and each of the first, second, third and fourth endplates has a plurality of receptacles (i) for receiving each of said plurality of protrusions when the device is folded and (ii) for releasing each of said plurality of protrusions when the device is folded. In some embodiments, each protrusion on one endplate can have a mating surface on an opposing endplate, such as, for example, a recess, groove, channel or port, for mating with or receiving an opposing or adjacent endplate. In some embodiments, the first plurality of protrusions and the second plurality of protrusions slidably translate in a tongue and groove configuration to provide additional rigidity to the upper end plate assembly during the horizontal deployment, and the third plurality of protrusions and the fourth plurality of protrusions slidably translate in a tongue and groove configuration to provide additional rigidity to the lower end plate assembly during the horizontal deployment.

[0022] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred or exemplary aspects of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. [Brief description of the drawings]

[0023] The novel features of the present disclosure are set forth with particularity in the appended claims, but a better understanding of the features and advantages of the invention taught herein can be obtained by reference to the following detailed description that sets forth illustrative embodiments in which the principles of the disclosure are utilized and the accompanying drawings in which:

[0024] [Figure 1-4] FIG 1 shows an example of an expandable fusion device in an initial folded state implanted between two vertebral bodies according to some embodiments. FIG 2 shows the expandable fusion device of FIG 1 in a fully deployed state implanted between two vertebral bodies according to some embodiments. FIG 3 shows a perspective view of an example of an expandable fusion device in a folded state according to some embodiments. FIG 4 shows a perspective view of the expandable fusion device of FIG 3 in a fully deployed state according to some embodiments. [Figure 5-6] Figure 5 is an exploded perspective view of the expandable fusion device of Figure 3, according to some embodiments. Figure 6 is a perspective view of one example of an actuator forming part of the expandable fusion device of Figure 3, according to some embodiments. [Figure 7-9] Figure 7 is a top view of an example of a distal wedge forming part of the expandable fusion device of Figure 3, according to some embodiments. Figure 8 is a perspective view of the distal wedge of Figure 7, according to some embodiments. Figure 9 is another perspective view of the distal wedge of Figure 8, according to some embodiments. [Figure 10-12]

[0023] Figure 10 is a top view of an example of a proximal wedge forming part of the expandable fusion device of Figure 3, according to some embodiments. Figure 11 is a perspective view of the proximal wedge of Figure 10, according to some embodiments. Figure 12 is another perspective view of the proximal wedge of Figure 10, according to some embodiments. [Figure 13-16] Figure 13 is a side view of an example of a distal ramp forming part of the deployable fusion device of Figure 3, according to some embodiments. Figures 14-15 are perspective views of the distal ramp of Figure 13, according to some embodiments. Figure 16 is a top view of the distal ramp of Figure 13, according to some embodiments. [Figure 17-20]Figures 17-19 are perspective views of an example of a proximal ramp forming part of the deployable fusion device of Figure 3, according to some embodiments. Figure 20 is a top view of the proximal ramp of Figure 17, according to some aspects. [Figure 21-23] Figures 21-22 are perspective views of one example of an endplate that forms part of the expandable fusion device of Figure 3, according to some embodiments. Figure 23 is a top view of the endplate of Figure 21, according to some embodiments. [Figure 24-25]

[0031] Figures 24 and 25 are perspective views of another example of an expandable fusion device in a fully deployed state, according to some embodiments. [Figure 26-27]

[0031] Figure 26 is an exploded perspective view of the expandable fusion device of Figure 25, according to some embodiments.

[0032] Figure 27 is a perspective view of one example of a distal ramp forming part of the expandable fusion device of Figure 25, according to some embodiments. [Figure 28-29]

[0031] Figure 28 is a perspective view of another example of an expandable fusion device in a fully deployed state, according to some embodiments.

[0032] Figure 29 is an exploded perspective view of the expandable fusion device of Figure 28, according to some embodiments.

[0025] [Figure 30-31]

[0036] Figure 30 is a perspective view of one example of a distal ramp that forms part of the expandable fusion device of Figure 28, according to some embodiments.

[0037] Figure 31 is a perspective view of another example of a distal ramp that forms part of the expandable fusion device of Figure 3, according to some embodiments. [Figure 32-33]

[0033] Figure 32 is a perspective view of another example of an expandable fusion device in a fully deployed state, according to some embodiments.

[0034] Figure 33 is a perspective view of one example of a proximal ramp that forms part of the expandable fusion device of Figure 32, according to some embodiments. [Figure 34-38] Figure 34 is a perspective view of another example of an expandable fusion device in a width-deployed state, according to some embodiments. Figure 35 is a perspective view of an example of an actuator forming part of the expandable fusion device of Figure 34, according to some embodiments. Figures 36-38 are cross-sectional views of the expandable fusion device of Figure 34 in various deployed states, according to some embodiments. [Figure 39-42] Figure 39 is a perspective view of another example of an expandable fusion device in a width-deployed state, according to some embodiments. Figures 40-41 are cross-sectional views of the expandable fusion device of Figure 39 in various deployed states, according to some embodiments. Figure 42 is a cross-sectional view of a proximal portion of the expandable fusion device of Figure 39, according to some embodiments. [Figure 43-48] FIG. 43 is a perspective view of another example of an expandable fusion device in a fully deployed state, according to some embodiments. FIG. 44 is a perspective view of an example of an actuator forming part of the expandable fusion device of FIG. 43, according to some embodiments. FIGs. 45-47 are cross-sectional views of the expandable fusion device of FIG. 43 in various deployed states, according to some embodiments. FIG. 48 is a cross-sectional view of a proximal portion of the expandable fusion device of FIG. 43, according to some embodiments. [Figure 49-53] Figure 49 is a perspective view of another example of an expandable fusion device in a fully compressed state, according to some embodiments. Figure 50 is a perspective view of an example of a locking element forming part of the expandable fusion device of Figure 49, according to some embodiments. Figures 51-53 are cross-sectional views of the expandable fusion device of Figure 49 in various expanded states, according to some embodiments. [Fig. 54-56] Figure 54 is a perspective view of another example of a locking element forming part of the expandable fusion device of Figure 49, according to some embodiments. Figures 55-56 are cross-sectional views of the expandable fusion device of Figure 48 in various deployed states, according to some embodiments. [Fig. 57-59] Figure 57 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. Figure 58 is a perspective view of Figure 57 in a width-collapsed state, according to some embodiments. Figure 59 is an exploded perspective view of the expandable fusion device of Figure 57, according to some embodiments. [Figure 60-65] Figures 60-61 are perspective views of an example of a distal ramp forming part of the expandable fusion device of Figure 57, according to some embodiments. Figure 62 is a perspective view of an example of an endplate forming part of the expandable fusion device of Figure 57, according to some embodiments. Figures 63-65 are plan views of the expandable fusion device of Figure 57 in various deployed states, according to some embodiments. [Figure 66-69] FIG 66 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. FIG 67 is a perspective view of the expandable fusion device of FIG 66 in a width-expanded state, according to some embodiments. FIG 68 is a perspective view of the expandable fusion device of FIG 66 in a fully-expanded state, according to some embodiments. FIG 69 is a perspective view of one example of proximal and distal ramps forming part of the expandable fusion device of FIG 66, according to some embodiments.

[0026] [Figure 70-75] FIG. 70 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. FIG. 71 is a perspective view of the expandable fusion device of FIG. 70 in a width-expanded state, according to some embodiments. FIG. 72 is a perspective view of the expandable fusion device of FIG. 70 in a fully-expanded state, according to some embodiments. FIG. 73 is a perspective view of an example of a width stabilizer that forms part of the expandable fusion device of FIG. 71, according to some embodiments. FIGS. 74-75 are cross-sectional views of the expandable fusion device of FIG. 70 in various expanded states, according to some embodiments. [Fig. 76-80] Figure 76 is a perspective view of another example of an expandable fusion device in a fully deployed state, according to some embodiments. Figure 77 is a perspective view of an example of a width stabilizer forming part of the expandable fusion device of Figure 76, according to some embodiments. Figures 78-80 are cross-sectional views of the expandable fusion device of Figure 76 in various deployed states, according to some embodiments. [Fig. 81-84] FIG 81 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. FIG 82 is a perspective view of the expandable fusion device of FIG 81 in a fully deployed state, according to some embodiments. FIG 83 is a perspective view of the expandable fusion device of FIG 81 without endplates in a width-deployed state, according to some embodiments. FIG 84 is a perspective view of one example of a width stabilizer that forms part of the expandable fusion device of FIG 84, according to some embodiments. [Fig. 85-88]Figure 85 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. Figure 86 is a perspective view of an example of a width stabilizer that forms part of the expandable fusion device of Figure 85, according to some embodiments. Figures 87-88 are perspective views of the expandable fusion device of Figure 85 in various expanded states with endplates removed, according to some embodiments. [Fig. 89-92] FIG 89 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. FIG 90 is a perspective view of the expandable fusion device of FIG 89 in a width-expanded state, according to some embodiments. FIG 91 is a perspective view of the expandable fusion device of FIG 89 in a fully-expanded state, according to some embodiments. FIG 92 is a perspective view of the expandable fusion device of FIG 89 shown with an alternative example of a width stabilizer, according to some embodiments. [Fig. 93-99] Figures 93-94 are top and perspective views, respectively, of an upper endplate assembly forming part of the expandable fusion device of Figure 89, according to some embodiments. Figures 95-99 are cross-sectional views of the upper endplate assembly of Figure 93 depicting various examples of width stabilizers, according to some embodiments. [Figure 100-105] FIG. 100 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. FIG. 101 is a perspective view of the expandable fusion device of FIG. 100 in a width-expanded state, according to some embodiments. FIG. 102 is a perspective view of the expandable fusion device of FIG. 100 in a fully expanded state, according to some embodiments. FIG. 103 is a perspective view of an example of a distal ramp forming part of the expandable fusion device of FIG. 100, according to some embodiments. FIG. 104 is a perspective view of an example of a proximal ramp forming part of the expandable fusion device of FIG. 100, according to some embodiments. FIG. 105 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. [Fig. 106-109]FIG 106 is a perspective view of another example of an expandable fusion device in a fully compressed state, according to some embodiments. FIG 107 is a perspective view of the expandable fusion device of FIG 106 in a width-deployed state, according to some embodiments. FIG 108 is a perspective view of the expandable fusion device of FIG 106 in a fully-deployed state, according to some embodiments. FIG 109 is a cross-sectional view of the expandable fusion device of FIG 108, according to some embodiments. [Figure 110-113] 110-113 are plan views of the expansion fusion device of FIG. 106 in various deployment states, according to several embodiments. [Fig. 114-116] Figure 114 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. Figures 115-116 are perspective views of the expandable fusion device of Figure 114 in various expanded states, according to some embodiments.

[0027] [Fig. 117-121] Figures 117-118 are perspective views of the expandable fusion device of Figure 114 in various deployed states according to some embodiments. Figures 119-120 are cross-sectional views of the expandable fusion device of Figure 114 according to some embodiments. Figure 121 is a perspective view of the expandable fusion device of Figure 114 with endplates removed according to some embodiments. [Fig. 122-124] Figure 122 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. Figures 123-124 are perspective views of the expandable fusion device of Figure 122 in various expanded states, according to some embodiments. [Fig. 125-128] Figure 125 is a perspective view of the expandable fusion device of Figure 122 in various deployed states according to some embodiments. Figures 126-127 are top views of the expandable fusion device of Figure 122 according to some embodiments. Figure 128 is a perspective view of the expandable fusion device of Figure 122 in a fully deployed state according to some embodiments. [Fig. 129-133] Figures 129-130 are perspective views of the proximal end of the expandable fusion device of Figure 122, according to some embodiments. Figures 131-133 are perspective views of several examples of when a shim can be used with the expandable fusion device of Figure 122, according to some embodiments. [Fig. 134-138] Figure 134 is a perspective view of another example of an expandable fusion device in a fully collapsed state, according to some embodiments. Figure 135 is a perspective view of the expandable fusion device of Figure 134 in a width-expanded state, according to some embodiments. Figure 136 is a perspective view of the expandable fusion device of Figure 134 in a fully-expanded state, according to some embodiments. Figures 137-138 are perspective views of a wedge that forms part of the expandable fusion device of Figure 134, according to some embodiments. [Figure 139-140] 139-140 are top views of the spread-out fusion device of FIG. 134 in a wide-spread state, according to some embodiments. [Figure 141-143] 141-143 are perspective views of another example of an expandable fusion device, according to some embodiments. [Fig. 144-145] 144-145 are perspective views of another example of an expandable fusion device, according to some embodiments. [Fig. 146-148] 146-148 are perspective views of another example of an expandable fusion device, according to some embodiments. [Figure 149-151] 149-151 are end views of the expansion fusion device of FIG. 146, according to some embodiments. [Fig. 152-156] FIG. 152 is a perspective view of another example of an expandable fusion device configured for lordotic deployment in a fully deployed state, according to some embodiments. FIG. 153 is a perspective view of an example of a proximal ramp forming a part of the expandable fusion device of FIG. 152, according to some embodiments. FIG. 154 is a perspective view of another example of an expandable fusion device configured for lordotic deployment in a fully deployed state, according to some embodiments. FIG. 155 is a perspective view of an example of a proximal ramp forming a part of the expandable fusion device of FIG. 154, according to some embodiments. FIG. 156 is a perspective view of another example of an expandable fusion device configured for transverse lordotic deployment in a fully deployed state, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Expandable spinal fusion devices, systems, and methods of using the same are provided to reduce surgical complications and risks through the use of minimal to very small intervertebral distraction, or perhaps no distraction, and through the use of small surgical channels. The devices, systems, and methods allow desired width control in device deployment through a single device variable transverse deployment system that provides an on-the-fly choice of desired footprint, either larger and possibly biased footprint to achieve desired alignment, or perhaps to avoid device collapse during use. This also allows desired control of height deployment through incremental cranio-caudal deployment of the device incrementally increased at a desired amount and rate via a drive system to achieve desired intervertebral height and / or pressure to controllably decompress neural elements and reach a safe desired intervertebral height by incremental control of deployment rate, amount, and pressure applied to surrounding tissue. Desired control of adjacent vertebral body alignment is obtained through a design that gives the surgeon the freedom to select any desired deployment width, and achieving the desired width independent of incremental height control. Devices, systems and methods are also provided that allow control of the desired contact area between the device and the upper and lower vertebral endplates, achieved, for example, using an interdigitated endplate system.

[0029] The fusion device taught herein can include a proximal wedge, a distal wedge, a first ramp, a second ramp, a third ramp, a fourth ramp, a first endplate, a second endplate, a third endplate, a fourth endplate, an actuator, and a retention member designed to constrain linear motion of the actuator relative to the proximal wedge. The actuator can pull the proximal and distal wedges together or away from each other, force the first ramp away from the fourth ramp, force the second ramp away from the third ramp, force the second ramp away from the third ramp, and force the first ramp away from or close to the second ramp and the third ramp away from or close to the fourth ramp, thereby moving the first endplate, second endplate, third endplate, and fourth endplate outwardly from each other and into a deployed configuration.

[0030] Optionally, in any aspect, the device can have a width that includes an outer width of at least one of the upper end plate assembly and the lower end plate assembly. Optionally, in any aspect, the device can have a height that includes an outer distance between the upper end plate assembly and the lower end plate assembly. Optionally, in any aspect, actuation of the drive mechanism a first number of actuations in a first actuation direction can increase the width without increasing the height. Optionally, in any aspect, actuation of the drive mechanism a second number of actuations beyond the first number of actuations in the first actuation direction can increase at least one of the height and the width.

[0031] Those skilled in the art will recognize the range of deployment possible and improved autonomous control of deployment in both cranio-caudal and lateral directions conferred upon the art by the devices presented herein. In some embodiments, the width of the device (the dimension in which the device deploys in the lateral direction in vivo) can be any amount or range from about 5 mm to about 30 mm in 1 mm increments in the collapsed state, and from about 10 mm to about 60 mm in 1 mm increments in the deployed state. In some embodiments, the height of the device (the dimension in which the device deploys in the cranio-caudal direction in vivo) can be from about 5 mm to about 20 mm in the collapsed state, and from about 10 mm to about 40 mm in the deployed state. In some embodiments, the percent deployment in either direction can range from about 1% to about 100%, and any percentage therein can range in 1% increments. Thus, in the folded state, the width of the device is about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, about 20 mm, about 21 mm, about 22 mm, about 23 mm, about 24 mm, about 25 mm, about 26 mm, about 27 mm, about 28 mm, about 29 mm, about 30 mm, or any amount or range therein in 0.1 mm increments, and the height can be about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, about 20 mm, or any amount or range therein in 0.1 mm increments.Similarly, in the deployed state, the width of the device may be about 10 mm, about 12 mm, about 14 mm, about 16 mm, about 18 mm, about 20 mm, about 24 mm, about 24 mm, about 26 mm, about 28 mm, about 30 mm, about 32 mm, about 34 mm, about 36 mm, about 38 mm, about 40 mm, about 42 mm, about 44 mm, about 46 mm, about 48 mm, about 50 mm, about 52 mm, about 54 mm, about 56 mm, about 58 mm, The height can be about 10 mm, about 12 mm, about 14 mm, about 16 mm, about 18 mm, about 20 mm, about 22 mm, about 24 mm, about 26 mm, about 28 mm, about 30 mm, about 32 mm, about 34 mm, about 36 mm, about 38 mm, about 40 mm, or any amount or range therein in increments of 0.1 mm. In some embodiments, any combination or range of the above height and width dimensions can be used together. In some embodiments, for example, the device can have a height in the range of about 7-8 mm when collapsed, while the height when deployed in vivo ranges from about 12-14 mm, and a width in the range of about 7-20 mm when collapsed, while the width when deployed in vivo ranges from about 14-40 mm. In some embodiments, for example, the device can have a height in the range of about 6-10 mm when collapsed, while the height when deployed in vivo is in the range of about 12-20 mm, and a width in the range of about 6-24 mm when collapsed, while the width when deployed in vivo is in the range of about 12-48 mm.

[0032] 1-2 illustrate an example of one embodiment of an expandable fusion device 7 of the type disclosed herein, and is representative of the type of expansion common to each of the embodiments described below by way of example. By way of example, FIG. 1 illustrates the expandable fusion device 7 in an initial collapsed state disposed in the intervertebral space 3 between adjacent vertebral bodies 2, 4, with endplates 6, 8, respectively, as a surgical access path 5. Implantation of the expandable fusion device 7 in an initial collapsed state reduces the impaction force required for implantation and the size of the surgical path 5. FIG. 2 illustrates the expandable fusion device 7 in an expanded state (expanded in both width and height) mating with the vertebral endplates 6, 8 of the adjacent vertebrae 2, 4, respectively. The expandable fusion device 7 is longer than it is wide in the initial collapsed state, and the endplates can be longer than they are wide. Deployment (e.g., intraoperative deployment) of the fusion device 7 while positioned between the vertebral bodies 2, 4 allows for an increase in the width of the fusion device 7 and a corresponding increase in the spacing and contact area (or footprint) between the fusion device 7 and the endplates 6, 8 beyond that otherwise permitted by the surgical corridor 5. Additionally, intraoperative deployment of the expandable fusion device 7 facilitates application of a deployment force to the endplates 6, 8 to increase and maintain the distance and / or angle between the vertebrae 2, 4 by increasing and maintaining the height of the implant and / or the angular orientation of its components.

[0033] Preferably, the various components of the fusion device 7 (and further embodiments) described herein are fabricated from titanium alloys (including but not limited to Ti-6Al-4V alloy) or cobalt alloys, including but not limited to CoCrMo alloys, and fabricating some of the screw components of the fusion device 7 from CoCr-based alloys allows for increased strength, reduced size, and other performance considerations. However, it should be understood that the various components of the expandable fusion device 7 (and / or any embodiment described herein) may be made from a variety of materials including, but not limited to, metals and alloys (e.g., commercially pure titanium, titanium alloys including Ti-6Al-4V based alloys, cobalt alloys including CoCrMo alloys, stainless steels, tantalum and its alloys, platinum and its alloys, etc.), polymers (e.g., PEEK, PEKK, PEKEK, PEI, PET, PETG, UHMWPE, PPSU, acetal, polyacetal, etc., including carbon fiber reinforced varieties and other filled varieties including, for example, carbon fiber, carbon nanotubes, graphene, barium sulfate, or hydroxyapatite), ceramics (e.g., various metallized ceramics and metal ceramic composites with aluminum oxide, zirconium oxide, silicon nitride, diamond-like carbon, etc.).

[0034] Thus, in any embodiment, at least one of the actuator, wedge assembly, ramp assembly, upper end plate assembly, and lower end plate assembly may comprise titanium, cobalt, stainless steel, tantalum, platinum, PEEK, PEKK, carbon fiber, barium sulfate, hydroxyapatite, ceramic, zirconium oxide, silicon nitride, carbon, bone graft, demineralized bone matrix product, synthetic bone substitute, bone morphogen, bone growth inducer, or any combination thereof.

[0035] Optionally, in any embodiment, bone allograft, bone autograft, bone xenograft, demineralized bone matrix product, synthetic bone substitute, bone morphogen, or other bone growth inducing material is introduced into and / or around fusion device 7 to further promote and encourage intervertebral fusion. In one embodiment, bone graft, demineralized bone matrix product, synthetic bone substitute, bone morphogen, or other bone growth inducing material is preferably loaded or injected into fusion device 7, preferably after deployment, while in other embodiments, graft material may be introduced into or around fusion device 7 into intervertebral space 3 prior to implantation, or after implantation but prior to deployment.

[0036] Optionally, in any embodiment, the device further includes one or more pins. Optionally, in any embodiment, at least one of the first endplate, the second endplate, the third endplate, and the fourth endplate can include a bone-facing surface that does not contain a through hole. Optionally, in any embodiment, at least two of the first endplate, the second endplate, the third endplate, and the fourth endplate can be identical. Optionally, in any embodiment, at least two of the first endplate, the second endplate, the third endplate, and the fourth endplate can have mirror image symmetry.

[0037] 3-23 illustrate an example of an expandable fusion device 10 for implantation between two adjacent vertebrae, according to some embodiments. Referring initially to FIGS. 3-5 by way of example only, the expandable fusion device 10 of this embodiment includes an actuator 12, a distal wedge 14, a proximal wedge 16, a pair of distal ramps 18a, 18b, a pair of proximal ramps 20a, 20b, a plurality of endplates 22a-22d, and a plurality of guide pins 23. As described in more detail below, the distal and proximal wedges 14, 16 are coupled to the actuator 12. The distal ramps 18a, 18b are slidably coupled to the distal wedge 14. The proximal ramps 20a, 20b are slidably coupled to the proximal wedge 16. The plurality of endplates 22a-22d are slidably coupled to the ramps 18a, 18b, 20a, 20b. More specifically, the first endplate 22a includes a first upper endplate in slidable engagement with the first distal ramp 18a and the first proximal ramp 20a, the second endplate 22b includes a second upper endplate in slidable engagement with the second distal ramp 18b and the second proximal ramp 20b, the third endplate 22c includes a first lower endplate in slidable engagement with the first distal ramp 18a and the first proximal ramp 20a, and the fourth endplate 22d includes a second lower endplate in slidable engagement with the second distal ramp 18b and the second proximal ramp 20b. In the exemplary embodiment, the endplates 22a-22d are also in sliding contact with the wedges 14, 16 when the device is in the initial folded state.

[0038] FIG. 6 illustrates one example of an actuator 12 forming part of the expandable fusion device 10 of the present embodiment. By way of example only, the actuator 12 may include a cylindrical elongate shaft having a distal end 24, a proximal end 26, and an anterior-posterior axis L. At least a portion of the distal end 24 includes a first thread mechanism 28. Similarly, at least a portion of the proximal end 26 includes a second thread mechanism 30. The first and second thread mechanisms 28, 30 may be separated by a non-threaded section 29 disposed between the first thread mechanism 289 and the second thread mechanism 30. At least one of the distal and proximal ends 24, 26 includes a drive mechanism 32 configured to mate with a drive instrument (not shown) aligned with the anterior-posterior axis L to actuate the actuator. Each of the first and second thread mechanisms 28, 30 includes threads disposed externally about the shaft of the actuator 12. By way of example, the first thread mechanism 28 and the second thread mechanism 30 may have opposite thread orientations. Alternatively, the first and second thread mechanisms 28, 30 may have the same thread direction. For example, at least one of the first and second thread mechanisms 28, 30 may include right-hand threads. Alternatively (or additionally), at least one of the first and second thread mechanisms 28, 30 may include left-hand threads. The drive mechanism 32 includes a recessed area configured to accommodate a drive device. The recessed area may include any shape capable of mating with a corresponding drive element of the drive device, including (by way of example only) but not limited to slot, Phillips, Pozidriv, Friersun, Robertson, 12-point flange, hex socket, safety hex socket, star drive, safety torx, ta, tri-point, tri-wing, spanner head, clutch, one-way, double square, triple square, polydrive, spline drive, double hex, bristol, pentalobe recess, or any other shape of recess. Alternatively, the drive mechanism 32 may include a protrusion (e.g., a hexagonal, hexalobular, or square protrusion, or a protrusion of other shape) extending longitudinally from the proximal and / or distal end and configured to be coupled to a drive device.

[0039] Optionally, in any aspect, the actuator can have a distal end and a proximal end. Optionally, in any aspect, at least a portion of the distal end can include a first thread mechanism. Optionally, in any aspect, at least a portion of the proximal end can include a second thread mechanism. Optionally, in any embodiment, the proximal end can include a drive mechanism. Optionally, in any aspect, at least one of the first thread mechanism and the second thread mechanism can include threads disposed on the exterior of the actuator. Optionally, in any aspect, at least one of the first thread mechanism and the second thread mechanism can have opposite thread senses.

[0040] Optionally, in any embodiment, the wedge assembly may include a distal wedge and a proximal wedge. Optionally, in any embodiment, actuation of the drive mechanism in a first direction may cause the distal wedge and the proximal wedge to move toward each other. Optionally, in any embodiment, the distal wedge may include a third screw mechanism, and the third screw mechanism may be threadedly coupled to the first screw mechanism. Optionally, in any embodiment, the proximal wedge may include a fourth screw mechanism, and the fourth screw mechanism may be threadedly coupled to the second screw mechanism. Optionally, in any embodiment, the third screw mechanism may include a screw disposed on an inner side of the distal wedge. Optionally, in any embodiment, the fourth screw mechanism may include a screw disposed on an inner side of the proximal wedge.

[0041] 7-9 illustrate an example of a distal wedge 14 according to the present embodiment. By way of example, the distal wedge 14 may have an isosceles trapezoidal prism shape including a distal face 36, a proximal face 38, and a thread feature 40 extending axially between the distal and proximal faces 36, 38. The distal wedge 14 includes distally tapered top and bottom surfaces 41, 43 that aid in the insertion process. The distal wedge 14 further includes one or more mating features 42 configured for temporary attachment to an insertion tool, such as one or more recesses 42 in the top and / or bottom surfaces 41, 43 of the distal wedge 14. The thread feature 40 includes internal threads configured for threaded engagement with the first thread feature 28 of the actuator 12. The distal wedge 14 may be configured for slidable engagement with the first and second distal ramps 18a, 18b and / or the end plates 22a, 22b, 22c, 22d. To facilitate slidable coupling with the first and second distal ramps 18a, 18b, the distal wedge 14 includes a number of tongue and groove connectors 44a-44d, each of which includes a ridge or tongue (e.g., ridges 46a-46d) and a slot or groove (e.g., slots 48a-48d), and a number of control slots 50a-50d. By way of example only, the tongue and groove connectors 44a-44d slidably engage the tongue and groove connectors 88a-88d of the distal ramps 18a, 18b, and the control slots 50a-50d slidably receive the protrusions 94a-94d of the distal ramps 18a, 18b. By way of example, tongue and groove connector 44a includes upper right tongue and groove connector 44a (when looking at proximal face 38 of distal wedge 14 (as shown in FIG. 9 )), tongue and groove connector 44b includes lower right tongue and groove connector 44b, tongue and groove connector 44c includes upper left tongue and groove connector 44c, and tongue and groove connector 44d includes lower left tongue and groove connector 44d. By way of example, upper right tongue and groove connector 44a and upper left tongue and groove connector 44c, and lower right tongue and groove connector 44b and lower left tongue and groove connector 44d are mirror symmetrical with respect to the sagittal plane of distal wedge 14. Similarly, the upper right tongue and groove connector 44a and the lower right tongue and groove connector 44b, and the upper left tongue and groove connector 44c and the lower left tongue and groove connector 44d have mirror image symmetry with respect to the transverse plane of the distal wedge 14.By way of example, the median plane of each of the tongue and groove connectors 44a-44d is oriented at a frontal contact angle from the sagittal plane of the distal wedge 14.

[0042] Optionally, in any embodiment, the lamp assembly can include a first distal lamp, a second distal lamp, a first proximal lamp, and a second proximal lamp. Optionally, in any embodiment, the slidable coupling between at least one of the wedge assembly and the lamp assembly, the lamp assembly and the upper end plate assembly, and the lamp assembly and the lower end plate assembly is at a front contact angle from the front-to-rear axis. The front contact angle can be, for example, in a range including about 0 degrees to about 90 degrees. Thus, in any embodiment, the front contact angle can be at least about 0 degrees.

[0043] Optionally, in any embodiment, the slidable coupling between the wedge assembly and the lamp assembly, the lamp assembly and the upper end plate assembly, and the lamp assembly and the lower end plate assembly may include a protrusion and a slot. Optionally, in any embodiment, the protrusion extends from at least one of the wedge assembly, the lamp assembly, the upper end plate assembly, and the lower end plate assembly, and the slot is disposed in at least one of the upper end plate assembly and the lower end plate assembly. Optionally, in any embodiment, the protrusion may include a pin, a ridge, a recess, a bolt, a screw, a bearing, or any combination thereof. Optionally, in any embodiment, the slot may include a through slot, a blind slot, a t-slot, a v-slot, a groove, or any combination thereof.

[0044] By way of example only, control slots 50a include the upper right control slot 50a (when looking at the proximal face 38 of distal wedge 14 (as shown in FIG. 9 )), control slots 50b include the lower right control slot 50b, control slots 50c include the upper left control slot 50, and control slots 50d include the lower left control slot 50d. By way of example, the upper right control slot 50a and the upper left control slot 50c, and the lower right control slot 50b and the lower left control slot 50d, have mirror image symmetry with respect to the sagittal plane of distal wedge 14. Similarly, the upper right control slot 50a and the lower left control slot 50b, and the upper left control slot 50c and the lower left control slot 50d, have mirror image symmetry with respect to the transverse plane of distal wedge 14. By way of example, the median plane of each of central slots 50a-40d is oriented at a frontal contact angle from the sagittal plane of distal wedge 14. Each of the control slots 50a-50d includes a translation stop 51 at the distal lateral end of the respective control slot. The translation stop 51 prevents further distal lateral translation of the protrusions 94a-94d of the distal ramps 18a, 18b, which stops the outward movement of the distal ramps 18a, 18b and thus the width expansion of the expanding fusion device 10.

[0045] 10-12 illustrate an example of a proximal wedge 16 according to this embodiment. By way of example, the proximal wedge 16 has an isosceles trapezoidal prism shape including a distal surface 52, a proximal surface 54, and a thread mechanism 56 extending axially between the distal and proximal surfaces 52, 54. The proximal wedge 34 further includes one or more mating mechanisms 58 configured for temporary attachment to an inserter, such as one or more recesses 58 on a top and / or bottom side of the distal wedge 16. The thread mechanism 56 includes internal threads configured for threadedly coupling with the second thread mechanism 30 of the actuator 12. The proximal wedge 16 can be configured for slidably coupling with the first and second proximal ramps 20a, 20b and / or the end plates 22a, 22b, 22c, 22d. To facilitate the slidable coupling, the proximal wedge 16 includes a number of tongue and groove connectors 60a-60d, each of which includes a ridge or tongue (e.g., ridges 62a-62d) and a slot or groove (e.g., slots 64a-64d), and a number of control slots 66a-66d. By way of example, the tongue and groove connectors 60a-60d slidably engage the tongue and groove connectors 130a-130d of the proximal ramps 20a, 20b, and the control slots 66a-66d slidably receive the protrusions 136a-136d of the proximal ramps 20a, 20b. By way of example, tongue and groove connector 60a includes the upper left tongue and groove connector 60a (when looking at distal surface 52 of proximal wedge 16 (as shown in FIG. 12 )), tongue and groove connector 60b includes the lower left tongue and groove connector 60b, tongue and groove connector 60b includes the lower left tongue and groove connector 60b, tongue and groove connector 60c includes the upper right tongue and groove connector 60c, and tongue and groove connector 60d includes the lower right tongue and groove connector 60d. By way of example, upper left tongue and groove connector 60a and upper right tongue and groove connector 60c, and lower left tongue and groove connector 60b and lower right tongue and groove connector 60d have mirror image symmetry with respect to the sagittal plane of proximal wedge 16. Similarly, the upper left tongue and groove connectors 60a, 60b, and the upper right tongue and groove connectors 60c, 60d have mirror symmetry with respect to the transverse plane of the proximal wedge 16. By way of example, the median plane of each of the tongue and groove connectors 60a-60d is oriented at a frontal contact angle from the sagittal plane of the proximal wedge 16.

[0046] By way of example only, the control slots 66a include the upper left control slot 66a, the control slots 66b include the lower left control slot 66b, the control slots 66c include the upper right control slot 66c, and the control slots 66d include the lower right control slot 66d (when looking at the distal surface 52 of the proximal wedge (as shown in FIG. 12 )). By way of example, the upper left control slot 66a and the upper right control slot 66c, and the lower left control slot 66b and the lower right control slot 66d, have mirror image symmetry with respect to the sagittal plane of the proximal wedge 16. Similarly, the upper left control slot 66a and the lower left control slot 66b, and the upper right control slot 66c and the lower right control slot 66d, have mirror image symmetry with respect to the transverse plane of the proximal wedge 16. By way of example, the median plane of each of the control slots 66a-66d is oriented at a frontal contact angle from the sagittal plane of the proximal wedge 16. Each of the control slots 66a-66d includes a translation stop 67 at the proximal outer terminus of that control slot. The translation stop 67 prevents further proximal outer translation of the projections 136a-136d of the proximal ramps 20a, 20b, which stops the outward movement of the proximal ramps 20a, 20b and thus the width expansion of the expanding fusion device 10.

[0047] By way of example, the first and second distal lamps 18a, 18b are identical mirror images of one another, and therefore only the second distal lamp 18b is described in detail herein, however it should be understood that the features described herein with respect to the second distal lamp 18b also apply unconditionally to the first distal lamp 18a. Similarly, the first and second proximal lamps 20a, 20b are identical mirror images of one another, and therefore only the first proximal lamp 20a is described in detail herein, however it should be understood that the features described herein with respect to the first proximal lamp 20a also apply unconditionally to the second proximal lamp 20b.

[0048] 13-16 illustrate an example of a second distal ramp 18b according to this embodiment. By way of example, the second distal ramp 18b has a distal end 76, a proximal end 78, an inner side 80 (e.g., oriented toward the actuator 12 in an assembled expandable fusion device 10), and an outer side 82 (e.g., oriented away from the actuator 12 in an assembled expandable fusion device 10). Generally, the second distal ramp 18b includes a rectangular prism that is divided into two lobes, a first lobe 84 and a second lobe 86, which facilitates height deployment of the expandable fusion device 10.

[0049] The second distal ramp 18b can be configured to slidably couple with the distal wedge 14 and / or end plates 22b, 22d. To facilitate the slidable coupling, the distal end 76 includes a pair of tongue and groove connectors 88c, 88d, each including a ridge or tongue (e.g., ridges 90c, 90d) and a slot or groove (e.g., slots 92c, 92d), and protrusions 94c, 94d. The tongue and groove connectors 88c, 88d slidably engage with the tongue and groove connectors 44c, 44d of the distal wedge 14, and the protrusions 94c, 94d slidably engage with the control slots 50c, 50d of the distal wedge 14. Although not shown, similar features (e.g., tongue and groove connectors and protrusions) of the first distal ramp 18a engage with corresponding features (e.g., tongue and groove connectors 44a, 44b and control slots 50a, 50b) of the distal wedge 14. By way of example, tongue and groove connector 44c includes tongue and groove connector 44c (e.g., FIG. 14), tongue and groove connector 44d includes lower tongue and groove connector 44d, protrusion 50c includes upper protrusion 50c, and protrusion 50d includes lower protrusion 50d. The upper and lower protrusions 50c, 50d are located at the respective medial distal corners of the second distal ramp 18b. The tongue and groove connectors 88c, 88d are angled in a medial-lateral direction to correspond to the angle of the tongue and groove connectors 44c, 44d of the distal wedge 14.

[0050] The first lobe 84 includes a chevron shape with an apex oriented in a proximal direction. The first lobe 84 includes a top surface 96, a bottom surface 98, a side surface 99, and angled proximal surfaces 100a, 100b. By way of example, the first lobe 84 has a generally L-shaped cross-sectional shape, however, it should be noted that the first lobe 84 may have any suitable cross-section, including (by way of example only) but not limited to, circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygonal, irregular polygonal, or combinations thereof. The angled proximal surface 100a slidably mates with the angled surface 152 of the second upper endplate 22b, and the angled proximal surface 100b slidably engages with the angled surface 152 of the second lower endplate 22d to facilitate height deployment. The first lobe 84 further includes a V-shaped recessed ramp slot 102 formed in the side surface 99 and configured to slidably receive one or more guide pins (see FIG. 5) therein to help stabilize the structure during height deployment and to provide a hard stop 103 for height deployment.

[0051] As an example, the V-shaped lamp slot 102 includes an upper lamp slot 102a and a lower lamp slot 102b. As shown by way of example in FIG. 13, the upper and lower lamp slots 102a, 102b may have equal slopes. The equal slopes of the lamp slots 102a, 102b allow the upper end plate assembly and the lower end plate assembly to translate upward and downward, respectively, from the actuator 12 at the same speed with respect to the rotation of the actuator 12. Alternatively, the lamp slots 102a, 102b may have unequal slopes. In such a configuration, the unequal slopes of the lamp slots 102a, 102b allow the upper end plate assembly and the lower end plate assembly to translate upward and downward, respectively, from the actuator 12 at different speeds with respect to the rotation of the actuator 12. Furthermore, as shown by way of example in FIG. 13, the upper and lower lamp slots 102a, 102b intersect toward a point. In some embodiments, the lamp slots 102a, 102b converge but do not intersect.

[0052] The second lobe 86 includes a truncated chevron shape with a truncated apex oriented in a proximal direction. The proximal lobe 86 includes a top surface 106, a bottom surface 108, a side surface 110, angled proximal surfaces 112a, 112b, and angled distal surfaces 114a, 114b. By way of example, the second lobe 86 has a generally trapezoidal cross-sectional shape (see, e.g., FIG. 16). The trapezoidal cross-section of the second lobe 86 is advantageous because having non-parallel leading contact surfaces of the double chevron shape (e.g., angled surfaces 100a, 100b and angled surfaces 112a, 112b) increases the stability of the construct during height deployment. Additionally, the trapezoidal shape of the second lobe 86 increases the surface area of ​​the proximal angled surfaces 112a, 112b and the distal angled surfaces 114a, 114b, which increases the strength of the construct to resist compressive forces after height deployment is complete. The angled proximal surface 112a slidably mates with the angled surface 156 of the second upper endplate 22b, and the angled proximal surface 112b slidably mates with the angled surface 156 of the second lower endplate 22d to facilitate height deployment.

[0053] 17-20 illustrate an example of a first proximal ramp 20a according to the present embodiment. By way of example, the first proximal ramp 20a has a proximal side 116, a distal side 118, an inner side 120 (e.g., oriented toward the actuator 12 in an assembled expandable fusion device 10), and an outer side 122 (e.g., oriented away from the actuator 12 in an assembled expandable fusion device 10). The first proximal ramp 20a includes an upper portion 124, a lower portion 126, and a vertical post 128 connecting the upper and lower portions 124, 126. By way of example, the vertical post 128 is disposed on the outer side 122 of the ramp 20a.

[0054] The first proximal ramp 20a can be configured to slidably couple with the proximal wedge 16 and / or the endplates 22a, 22c. To facilitate the slidable coupling, the proximal side 116 includes a pair of tongue and groove connectors 130a, 130b, each of which includes a ridge or tongue (e.g., ridges 132a, 132b) and a slot or groove (e.g., slots 134a, 134b), and a pair of protrusions 136a, 136b. The tongue and groove connectors 130a, 130b slidably engage with the tongue and groove connectors 60a, 60b of the proximal wedge 16, and the protrusions 136a, 136b slidably engage with the control slots 66a, 66b of the proximal wedge 16. Although not shown, similar features (e.g., tongue and groove connectors and protrusions) of second proximal ramp 20b mate with corresponding features (e.g., tongue and groove connectors 60c, 60d and protrusions) of proximal wedge 16. By way of example, tongue and groove connector 130a and protrusion 136a are disposed on upper portion 124 and include upper tongue and groove connector 130a and upper protrusion 136a, respectively, and tongue and groove connector 130b and protrusion 136 are disposed on lower portion 126 and include lower tongue and groove connector 130b and lower protrusion 136b, respectively. Upper and lower protrusions 136a, 136b are located at respective inner proximal corners of first proximal ramp 20a. The tongue and groove connectors 130 a , 130 b are angled in a medial-lateral direction to correspond with the angle of the tongue and groove connectors 60 a , 60 b of the proximal wedge 16 .

[0055] The vertical post 128 has a top surface 129a and a bottom surface 129b and is configured to extend vertically between the first upper endplate 22a and the first lower endplate 22c and is configured to slidingly engage with the vertical passages 150 in the first upper endplate 22a and the first lower endplate 22c. Because the post 128 is vertically oriented, when the first proximal ramp 20a (and the second proximal ramp 20b) are translated axially by the proximal wedge 16, only the endplates 22a, 22c can translate vertically relative to the first proximal ramp 20a.

[0056] Optionally, in any embodiment, the upper endplate assembly can include a first endplate and a second endplate, and the lower endplate assembly can include a third endplate and a fourth endplate. Optionally, in any embodiment, at least one of the first endplate and the second endplate, the third endplate and the fourth endplate, the first proximal ramp and the second proximal ramp, and the first distal ramp and the second distal ramp can have mirror image equivalence. Optionally, in any embodiment, at least one of the second endplate and the fourth endplate is larger than at least one of the first endplate and the third endplate. Optionally, in any embodiment, at least one of the outer surfaces of the first endplate, the second endplate, the third endplate, and the fourth endplate can include a texture configured to grip a vertebra.

[0057] By way of example, the various endplates 22a-22d are identical or identical mirror images of one another, and therefore at least one of the endplates needs to be described in more detail. By way of example only, endplate 22b (e.g., the second upper endplate) is described in detail herein, however, it should be understood that the features described herein with respect to endplate 22b also apply without reservation to the other endplates 22a, 22c, 22d. FIGS. 21-23 illustrate an example of an endplate 22b of the present disclosure. By way of example only, endplate 22b has a first (e.g., distal) end 138 and a second (e.g., proximal) end 140. In the illustrated embodiment, endplate 22b further includes a vertebrae-contacting outer surface 142 that contacts first end 138 and second end 140, and an inwardly facing surface 144 that contacts first end 138 and second end 140. Vertebral contacting outer surface 142 may include a texture configured to grip a vertebra.

[0058] By way of example, the texturing may include at least one of teeth, ridges, rough areas, metallic coatings, ceramic coatings, keels, spikes, protrusions, grooves, or any combination thereof. Inner-facing surface 144 is generally planar and smooth and will abut flush against a corresponding inner-facing surface of another endplate (e.g., endplate 22d) when fusion device 10 is fully retracted.

[0059] End plate 22b further includes a first angled slot 146 proximate first end 138 and extending from inboard surface 144 to outer surface 142, a second angled slot 148 disposed proximate first end 138 and extending from inboard surface 144 to outer surface 142, and a vertical passage 150 disposed proximate second end 140 and extending from inboard surface 144 to outer surface 142. Optionally, in any aspect, the slopes or shapes of angled slots 146, 148 may be equal to or different from one another.

[0060] The first angled slot 146 has a generally L-shaped cross-section, an angled surface 152 generally transverse to the anterior-posterior axis of the implant, and an angled surface 154 opposite the angled surface 152 and generally transverse to the anterior-posterior axis, the angled surfaces 152, 154 being parallel. The first angled slot 146 is sized and configured to slidably receive a portion (e.g., an upper portion) of the first lobe 84 of the second distal ramp 18b such that the distal surface 100a of the first lobe is in slidable interlock with the angled surface 152. Thus, after width deployment is completed, as the distal wedge 14 advances the distal ramp 18a towards the proximal wedge 16 (and the proximal ramp 20a), the endplate 22b is vertically displaced (resulting in height deployment) due in part to angular translation along the angled surface 152.

[0061] The angled slot 148 has a generally trapezoidal cross-section and an angled surface 156 generally transverse to the anterior-posterior axis of the implant and an angled surface 158 opposite the angled surface 156 and generally transverse to the anterior-posterior axis, the angled surfaces 156, 158 tapering toward one another. The second angled slot 148 is sized and configured to slidably receive a portion (e.g., an upper portion) of the second lobe 86 of the second distal ramp 18b such that the distal surface 112a of the second lobe 86 slidably interlocks with the angled surface 156. Thus, after width deployment is completed, as the distal wedge 14 advances the distal ramp 18a toward the proximal wedge 16 (and the proximal ramp 20a), the endplate 22b is vertically displaced (resulting in height deployment) due in part to angular translation along the angled surface 156.

[0062] The vertical passage 150 has a size and shape corresponding to the size and shape of the vertical post 128 of the proximal ramp 20b and is configured to facilitate vertical translation of the end plate 22b relative to the proximal ramp 22b.

[0063] By way of example, the endplate 22b may further include a chamfer 160 proximal to the first end 138 that reduces the height of the endplate 22b at the first end 138 to provide a tapered leading edge to facilitate introduction of the fusion device 10 between the adjacent vertebral bodies 2, 4. The endplate 22b may further include a pin opening 162 configured to hold a guide pin 23. The contact outer surface 142 may further include a plurality of openings corresponding to the angled slots 146, 148 and a vertical passageway 150. By way of example, the first opening 164 is disposed proximal to the first end 138 to correspond to the first angled slot 146. As such, the first opening 164 has a generally L-shaped cross section. It is sized and dimensioned to receive a portion of the first lobe 84 therein such that the upper surface 96 of the first lobe 84 is generally flush with the outer surface 142 when the expandable fusion device 10 is fully contracted. The second opening 166 is disposed proximal to the first opening 164 and corresponds to the second angled slot 148. As such, the second opening 166 has a generally trapezoidal cross-section. The second opening 166 is sized and dimensioned to receive a portion of the second lobe 86 therein such that the upper surface 106 of the second lobe 86 is generally flush with the outer surface 142 when the expandable fusion device 10 is fully contracted. The third opening 168 is disposed near the proximal end and corresponds to the vertical passageway 150. As such, the third opening 168 has a cross-sectional shape that matches the cross-sectional shape of the vertical passageway 150. The third opening 168 is sized and dimensioned to receive a portion of the vertical post 128 therein such that the upper surface 129a of the vertical post is generally flush with the outer surface 142 when the expandable fusion device 10 is fully contracted. This feature is beneficial in that allowing portions of ramps 18b, 20b to extend within endplate 22b flush with its outer surface 142 allows the deployable fusion device 10 to have a lower height h in the fully contracted position.

[0064] As illustrated in FIGS. 21-23, the contact outer surface 142 of the endplate 22b is generally planar, allowing the contact outer surface 142 to mate with an adjacent vertebral body (e.g., vertebral body 2 in FIG. 1). Alternatively, the contact outer surface 142 is curved in one or more planes to allow a higher degree of mating with the adjacent vertebral body 2. In another embodiment, the contact outer surface 142 is generally planar, but includes a generally straight ramp surface or a curved ramp surface. The ramp surface allows mating with the adjacent vertebral body 2 in a lordotic configuration and / or in a coronal tapered configuration, for example. Optionally, in any embodiment, the arrangement of ramped and non-ramped endplates of different heights, as well as non-ramped endplates of different heights, results in a geometry suitable for lordotic mating with the endplates. In one embodiment, all endplates of the fusion device 10 have the same length, while in other embodiments, it is further contemplated that some or all of the endplates have different lengths to better accommodate the subject anatomy. Optionally, one or more endplates may be shorter, longer, thinner, or wider than the others. Although various alternative endplate geometries are presented herein as separate embodiments, it should be understood that these alternative aspects are optional features that may be substituted or mixed / combined with any other aspect of the specification. It should also be understood that substituting any of the alternative features described above with endplate components may or will require mating components (e.g., endplates, ramps, wedges) to use the inverse and / or complementary geometry of these features for a possible proper fit between the various components of fusion device 10 and between these components and the surrounding anatomy, and that the geometry of this inverse and / or complementary geometry will necessarily result from the geometry of any alternative features described above.

[0065] Varying the slope of the slots 146, 148 or limiting the allowable movement between the ramps and slots 146, 148 in each of the end plates can result in, but are not limited to, first end 138 and second end 140 that deploy evenly at both the top and bottom of the fusion device 10, deploy unevenly at both the top and bottom, deploy evenly at the top and unevenly at the bottom, or deploy evenly at the bottom and unevenly at the top of the deployment device 10.

[0066] Optionally, in any embodiment, the first end plate 22a, the second end plate 22b, the third end plate 22c, and the fourth end plate 22d are substantially identical, although all four have the same set of features, the size and angular orientation inherent to these features need not be identical in all or any particular embodiment. Similarly, the first distal ramp 18a and the second distal ramp 18b are substantially identical to one another, and the first proximal ramp 20a and the second proximal ramp 20b are substantially identical to one another, although each pair has a pair of identical features, the size and angular orientation inherent to these features need not be identical in all or any particular embodiment. It should be noted that even if the ramps are identical in some embodiments, they can and should be rotated or mirror images as appropriate to be incorporated into the exemplary arrangements shown herein.

[0067] In use, the actuator 12 functions to draw the distal wedge 14 and the proximal wedge 16 together to move the endplates 22a, 22c away from the endplates 22b, 22d, which in turn move the first distal ramp 18a away from the second distal ramp 18b and the first proximal ramp 20a away from the second proximal ramp 20b (resulting in a width expansion of the fusion device 10). It should be noted that in another configuration, the actuator 12 functions to draw the distal wedge 14 and the proximal wedge 16 together to move the first distal ramp 18a away from the second distal ramp 18b and the first proximal ramp 20a away from the second proximal ramp 20b, which in turn move the endplates 22a, 22c away from the endplates 22b, 22d (resulting in a width expansion of the fusion device 10). Then, only after width expansion is at least partially completed, the first distal ramp 18a and the first proximal ramp 20a are drawn toward one another and the second distal ramp 18b and the second proximal ramp 20b are drawn toward one another. The movement of the first distal ramp 18a and the first proximal ramp 18b toward one another moves the first upper endplate 22a away from the first lower endplate 22c, and the movement of the second distal ramp 18b toward the second proximal ramp 20b moves the second upper endplate 22b away from the second lower endplate 22d (resulting in height expansion).

[0068] Optionally, in any embodiment, ramps 18a, 20a and ramps 18b, 20b begin to move toward each other only after width deployment has been fully or substantially or at least partially accomplished and ramps 18a, 18b have substantially reached their limits of travel relative to distal wedge 14 and ramps 20a, 20b have substantially reached their limits of travel relative to proximal wedge 16. Optionally, in any embodiment, this delay in height deployment is accomplished by end plates 22a, 22b, 22c, 22d slidably mating with distal wedge 14, and optionally, in some embodiments, with proximal wedge 16 during an initial portion of the width deployment process (in some embodiments, this engagement between the end plates and wedges may prevent or inhibit the distal and proximal ramps from moving toward each other, thereby inhibiting height deployment). As the wedges 14, 16 move towards each other during the width development process, they eventually disengage from the end plates 22a, 22b, 22c, 22d to allow height development. Optionally, delay in height development can be further achieved by an insert that inhibits height development until width development has substantially occurred.

[0069] Optionally, in any embodiment, a small gap may exist between the end plates and the wedges in the initial folded state. As a result, a first number of actuations in a first actuation direction increases both height and width, but not necessarily simultaneously. For example, depending on external load conditions and / or insertion configuration, the device may first begin to expand in height or width (e.g., the inserter may initially constrain either height or width expansion or neither). Then, actuation of the drive mechanism a second number of actuations in the first actuation direction beyond the first number of actuations increases at least one of height and width. In some embodiments, the first number of actuations of the actuator 12 results in at least some height expansion (and in some embodiments—exclusively height expansion), but further rotation of the actuator 12 increases at least one of width and height.

[0070] When fully assembled, the first expandable fusion device 10 is a stable assembly of components all held together in the assembly throughout their range of motion by the use of "tongue and groove" joints, e.g., fasteners such as pins, balls, screws, set screws, etc. Optionally, in any manner, fasteners are secured to one component to move an engagement feature (such as a track) on another component, thereby preventing disassembly of the components by limiting the range of motion of the first component to an amount allowable by the track feature.

[0071] As an example, at least one of the first endplate 22a, the second endplate 22b, the third endplate 22c, and the fourth endplate 22d contacts at least one of the distal wedge 18a and the proximal wedge 18b when the expandable fusion device 10 is in the folded state. Alternatively, at least one of the first endplate 22a, the second endplate 22b, the third endplate 22c, and the fourth endplate 22d does not contact at least one of the distal wedge 18a and the proximal wedge 18b when the expandable fusion device 10 is in the folded state. Contact between at least one of the first endplate 22a, the second endplate 22b, the third endplate 22c, and the fourth endplate 22d and at least one of the distal wedge 18a and the proximal wedge 18b affects the deployment of the expandable fusion device 10.

[0072] The expansion fusion device 10 has a width w that includes the lateral width of at least one of the upper endplate assemblies (e.g., endplates 22a, 22b) and the lower endplate assemblies (e.g., endplates 22c, 22d). Optionally, in any embodiment, the device has a height h that includes the lateral distance between the upper and lower endplate assemblies (e.g., between endplates 22a, 22c and / or 22b, 22d).

[0073] Optionally, in any embodiment, actuation of the actuation mechanism 32 a first number of actuations in a first actuation direction increases the width w without increasing the height h. Optionally, in any embodiment, actuation of the actuation mechanism 32 a second number of actuations beyond the first number of actuations in a first actuation direction increases at least one of the height h and the width w. Optionally, in any embodiment, actuation of the actuation mechanism 32 a second number of actuations beyond the first number of actuations in a first actuation direction increases both the height h and the width w, and actuation of the actuation mechanism 32 a third number of actuations beyond the second number of actuations in a first actuation direction increases the height h without increasing the width w. Optionally, in any embodiment, actuation of the actuation mechanism 32 a second number of actuations beyond the first number of actuations in a first actuation direction increases neither the height h nor the width w, and actuation of the actuation mechanism 32 a third number of actuations beyond the second number of actuations in a first actuation direction increases the height h without increasing the width w. Optionally, in any embodiment, the width w of device 10 is maximized upon at least a first number of actuations of actuation mechanism 32. Optionally, in any embodiment, the height h of device 10 is maximized upon at least a first and second number of actuations of actuation mechanism 32.

[0074] Optionally, in any embodiment, actuation of actuation mechanism 32 a second number of actuations beyond the first number of actuations in a first actuation direction increases both the height h and the width w. Optionally, in any embodiment, actuation of actuation mechanism 32 a second number of actuations beyond the first number of actuations in a first actuation direction increases the height h without increasing the width w.

[0075] Optionally, in any embodiment, actuation of actuation mechanism 32 in a first actuation direction at least the first number of actuations increases height h of device 10 by about 30% to about 400%. Optionally, in any embodiment, actuation of actuation mechanism 32 in a first actuation direction at least the first and second number of actuations increases width w of the device by about 14% to about 150%.

[0076] 24 illustrates an example of an expandable fusion device 210 for implantation between two adjacent vertebrae according to another embodiment of the disclosure. By way of example only, the expandable fusion device 210 of this embodiment includes an actuator 212, a distal wedge 214, a proximal wedge 216, a pair of distal ramps 218a, 218b, a pair of proximal ramps 220a, 220b, and a plurality of endplates 222a-d. As in the previously described embodiment, the distal and proximal wedges 214, 216 are coupled to the actuator 212. The distal ramps 218a, 218b are slidably coupled to the distal wedge 214. The proximal ramps 220a, 220b are slidably coupled to the proximal wedge 216. The plurality of endplates 222a-d are slidably coupled to the ramps 218a, 218b, 220a, 220b. In general, expandable fusion device 210 is substantially similar to expandable fusion device 10 described above, and any / all of the features described above with respect to fusion device 10 (and any other fusion device described herein) may be applied to fusion device 210, unless otherwise noted.

[0077] By way of example only, in this embodiment, device 210 does not include a guide pin (e.g., pin 23 of device 10), and as a result, end plates 222a, 222b, 222c, 222d do not include an opening (e.g., opening 162 of device 10) configured to receive a pin, and distal ramps 218a, 218b do not include a corresponding ramp slot (e.g., ramp slot 102 of device 10). Thus, in this embodiment (and any embodiment not having ramp slots and / or guide pins), height expansion may be stopped by a physical interface 251 between distal and proximal wedges 218a, 220a and distal and proximal wedges 218b, 220b, as shown by way of example in FIG. 24. Further, by way of example only, one or more of end plates 222a, 222b, 222c, 222d include a continuous, uninterrupted bone-contacting outer surface 242. That is, one or more of the end plates 222a, 222b, 222c, 222d do not include openings corresponding to the first slots, second slots, and / or vertical passages (eg, openings 164, 166, 168 of the device 10).

[0078] The expandable fusion device 210 of this embodiment may additionally or alternatively include any of the features, components, or characteristics of the various embodiment expandable fusion devices described herein. Additionally, additionally described expandable fusion devices may include additional features, components, or characteristics of the expandable fusion device 210.

[0079] 25-27 illustrate an example of an expandable fusion device 310 for implantation between two adjacent vertebrae according to another aspect of the disclosure. By way of example only, the expandable fusion device 310 of this aspect includes an actuator 312, a distal wedge 314, a proximal wedge 316, a pair of distal ramps 318a, 318b, a pair of proximal ramps 320a, 320b, a number of endplates 322a-322d, and a number of guide pins 323. As in the previously described embodiment, the distal and proximal wedges 314, 316 are coupled to the actuator 312. The distal ramps 318a, 318b are slidably coupled to the distal wedge 314. The proximal ramps 320a, 320b are slidably coupled to the proximal wedge 316. The plurality of end plates 322a-322d are slidably coupled to the ramps 318a, 318b, 320a, 320b. In general, the expandable fusion device 310 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 310, unless otherwise noted.

[0080] 27 illustrates an example of a second distal ramp 318b according to this embodiment. By way of example, the second distal ramp 318b has a distal end 376, a proximal end 378, an inner side 380 (e.g., oriented toward the actuator 312 in an assembled expandable fusion device 310), and an outer side 382 (e.g., oriented away from the actuator 312 in an assembled expandable fusion device 310). Generally, the second distal ramp 318b includes a rectangular prism that is divided into two lobes, a first lobe 384 and a second lobe 386, which facilitates height deployment of the expandable fusion device 310. The second distal ramp 318b can be configured to slidably couple with the distal wedge 314 and / or the endplates 322b, 322d. The slidable coupling with the wedge 314 is the same as described above with respect to the fusion device 10.

[0081] The first lobe 384 includes a general chevron shape with an apex oriented in the proximal direction. The first lobe 384 includes a top surface 396, a bottom surface 398, and a side surface 399. By way of example, the first lobe 384 has a generally L-shaped cross-sectional shape; however, it should be noted that the first lobe 384 may have any suitable cross-sectional shape including, but not limited to (by way of example only), a circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygonal, non-regular polygonal, irregular shape, or combinations thereof. The first lobe 384 further includes a V-shaped recessed ramp slot 402 formed in the side surface 399 and configured to slidably receive one or more guide pins 323 therein to help stabilize the structure during height deployment and to provide a hard stop for height deployment.

[0082] The second lobe 386 includes a half-chevron shape with a truncated apex oriented in the proximal direction. The second lobe 386 has a bottom surface 404 and a generally L-shaped cross-sectional shape, however, it should be noted that the second lobe 386 may have any suitable cross-sectional shape including (by way of example only) but not limited to circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygonal, non-regular polygonal, irregular, or combinations thereof.

[0083] By way of example, the second distal ramp 318b further includes an L-shaped cutting surface 400 configured to slidably engage a corresponding L-shaped cutting surface of the second proximal ramp 320b. The L-shaped cutting is advantageous in that it allows the distal ramps 318a, 318b and the proximal ramps 320a, 320b to be identical to one another. Furthermore, because the ramps 318a, 318b, 320a, 320b are identical, the end plates 322a, 322b, 322c, 322d are also identical. This reduces the number of different parts required during assembly.

[0084] The expandable fusion device 310 of this example embodiment may also or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any of the additionally described expandable fusion devices may include features, components, or characteristics of the expandable fusion device 310.

[0085] 28-31 illustrate one example of an expandable fusion device 410 for implantation between two adjacent vertebrae according to another embodiment of the disclosure. By way of example only, the expandable fusion device 410 of this embodiment includes an actuator 412, a distal wedge 414, a proximal wedge 416, a pair of distal ramps 418a, 418b, a pair of proximal ramps 420a, 420b, a number of endplates 422a-422d, and a number of guide pins 423. As in the previously described embodiment, the distal and proximal wedges 414, 416 are coupled to the actuator 412. The distal ramps 418a, 418b are slidably coupled to the distal wedge 414. The proximal ramps 420a, 420b are slidably coupled to the proximal wedge 416. The plurality of end plates 422a-422d are slidably coupled to the ramps 418a, 418b, 420a, 420b. In general, the expandable fusion device 410 is substantially similar to the expandable fusion device 310 described above, and any / all of the features of the fusion device 310 (and any other expandable fusion device described above, including specifically expandable fusion device 10) may be applied to the fusion device 410 unless otherwise stated.

[0086] 30 illustrates an example of a second distal ramp 418b according to the present embodiment. By way of example, the second distal ramp 418b has a distal end 476, a proximal end 478, an inner side 480 (e.g., oriented toward the actuator 412 in an assembled expandable fusion device 410), and an outer side 482 (e.g., oriented away from the actuator 412 in an assembled expandable fusion device 410). Generally, the second distal ramp 418b includes a rectangular prism that is divided into two lobes, a first lobe 484 and a second lobe 486, which facilitates height deployment of the expandable fusion device 410. The second distal ramp 418b can be configured to slidably couple with the distal wedge 414 and / or the endplates 422b, 422d. The slidable coupling with the wedge 414 is the same as described above with respect to the fusion device 10.

[0087] First lobe 484 includes a general chevron shape with an apex oriented in the proximal direction. First lobe 484 includes a top surface 496, a bottom surface 498, and a side surface 499. By way of example, first lobe 484 has a generally L-shaped cross-sectional shape; however, it should be noted that first lobe 484 may have any suitable cross-sectional shape including (by way of example only) but not limited to circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygon, non-regular polygon, irregular shape, or combinations thereof. First lobe 484 is configured for slidable engagement with first angled slot 446 of end plate 422b, where first angled slot 446 has a complementary cross-sectional shape. The first lobe 484 further includes a V-shaped recessed ramp slot 502 formed in the side surface 499 and configured to slidably receive one or more guide pins 423 therein to help stabilize the structure during height deployment and provide a hard stop for height deployment. The second lobe 486 includes a half-chevron shape with a truncated apex oriented in the proximal direction. The second lobe 486 has a bottom surface and a generally trapezoidal cross-sectional shape. The second lobe 486 is configured to slidably engage with the second angled slot 448 of the end plate 422b, the second angled slot 448 having a complementary trapezoidal cross-sectional shape.

[0088] By way of example, the second distal ramp 418b further includes an L-shaped cutting surface 500 configured to slidably engage a corresponding L-shaped cutting surface of the second proximal ramp 420b. The L-shaped cutting is advantageous in that it allows the distal ramps 418a, 418b and the proximal ramps 420a, 420b to be identical to one another. Furthermore, because the ramps 418a, 418b, 420a, 420b are identical, the end plates 422a, 422b, 422c, 422d are also identical. This reduces the number of different parts required during assembly.

[0089] The expandable fusion device 410 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 410.

[0090] 31 illustrates an example of an alternative embodiment of a dual chevron ramp according to some embodiments. For example, the dual chevron ramp comprises an alternative embodiment of the proximal ramp 18b described above in connection with the expandable fusion device 10, however, the proximal ramp 18b of this embodiment may be used with any expandable fusion device described herein that includes a dual chevron ramp.

[0091] In this embodiment shown in FIG. 31, the second lobe 86 includes a truncated chevron shape with a truncated apex oriented in a proximal direction. The proximal lobe 86 includes a top surface 106, a bottom surface 108, a side surface 110, curved proximal surfaces 112a, 112b, and curved distal surfaces 114a, 114b. By way of example, the second lobe 86 may have a generally truncated cross-sectional shape (see, e.g., FIG. 16). The truncated elliptical cross-sectional shape of the second lobe 86 in this example is similar to the trapezoidal cross-section of the second lobe 86 described above. Having non-parallel leading contact surfaces of the dual chevron shape (e.g., angled surfaces 100a, 100b and curved surfaces 112a, 112b) enhances the stability of the construct during height deployment. Additionally, the truncated elliptical shape of second lobe 86 increases the surface area of ​​proximal curved surfaces 112a, 112b and distal curved surfaces 114a, 114b (even compared to a trapezoidal cross-sectional shape), which increases the strength of the structure to resist compressive forces after height deployment is complete. Curved proximal surface 112a slidably mates with a corresponding curved surface of second upper endplate 22b, and curved proximal surface 112b slidably mates with a corresponding curved surface of second lower endplate 22d to facilitate height deployment.

[0092] 32-33 illustrate one example of an expandable fusion device 510 for implantation between two adjacent vertebrae according to another embodiment of the disclosure. By way of example only, the expandable fusion device 510 of this embodiment includes an actuator 512, a distal wedge 514, a proximal wedge 516, a pair of distal ramps 518a, 518b, a pair of proximal ramps 520a, 520b, a number of endplates 522a-522d, and a number of guide pins 523. As in the previously described embodiment, the distal and proximal wedges 514, 516 are coupled to the actuator 512. The distal ramps 518a, 518b are slidably coupled to the distal wedge 514. The proximal ramps 520a, 520b are slidably coupled to the proximal wedge 516. The plurality of end plates 522a-522d are slidably coupled to the ramps 518a, 518b, 520a, 520b. In general, the expandable fusion device 510 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 510, unless otherwise noted.

[0093] 33 illustrates an example of a proximal ramp 520b forming part of the expandable fusion device 510 according to some embodiments. Generally, the proximal ramp 520b resembles the distal half of the distal ramps described above (e.g., distal ramps 18a or 18b). By way of example only, the proximal ramp 520b has a proximal end 576, a distal end 578, an inner side 580 (e.g., oriented toward the actuator 512 in the assembled expandable fusion device 510), and an outer side (e.g., oriented away from the actuator 512 in the assembled expandable fusion device 510).

[0094] The proximal ramp 520b can be configured for slidable coupling with the proximal wedge 516 and / or the end plates 522b, 522d. To facilitate the slidable coupling, the proximal end 576 includes a pair of tongue and groove connectors 588c, 588d, such as the tongue and groove connectors previously described, that slidably engage corresponding tongue and groove connectors on the proximal wedge 516. The proximal ramp 520b further includes a single lobe 584 that includes a chevron shape with a truncated apex oriented distally. The lobe 584 includes a top surface 596, a bottom surface 598, a side surface 599, and angled distal surfaces 600a, 600b. By way of example, the lobes 584 have a generally L-shaped cross-sectional shape; however, it should be noted that the lobes 584 may have any suitable cross-sectional shape, including, but not limited to (by way of example only), circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygonal, non-regular polygonal, irregular, or combinations thereof. In a manner similar to that described above with respect to the previous embodiment, the angled distal surfaces 600a, 600b slidably mate with corresponding angled surfaces of the end plates 522b, 522d to facilitate height deployment. The lobes 584 further include a V-shaped recessed ramp slot 602 formed in the side surface 599 and configured to slidably receive one or more guide pins 523 therein to help stabilize the structure during height deployment and provide a hard stop for height deployment. According to this example embodiment, the proximal ramp 520a is a mirror image equivalent proximal ramp 520b.

[0095] The expandable fusion device 510 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Additionally, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 510.

[0096] 34-38 illustrate an example of an expandable fusion device 610 for implantation between two adjacent vertebrae according to another embodiment of the disclosure. By way of example only, the expandable fusion device 610 of this embodiment includes an actuator 612, a distal wedge 614, a proximal wedge 616, a pair of distal ramps 618a, 618b, a pair of proximal ramps 620a, 620b, a number of end plates 622a-622d, a number of guide pins 623, a nut 630, and a locking screw 634. As in the previously described embodiment, the distal and proximal wedges 614, 616 are coupled to the actuator 612. The distal ramps 618a, 618b are slidably coupled to the distal wedge 614. The proximal ramps 620a, 620b are slidably coupled to the proximal wedge 616. The plurality of end plates 622a-622d are slidably coupled to the ramps 618a, 618b, 620a, 620b. In general, the expandable fusion device 610 is substantially similar to the expandable fusion device 10 described above, and any / all of the mechanisms described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 610 unless otherwise noted. By way of example only, the expandable fusion device 610 illustrates alternative actuator mechanisms that may be applied to the example expandable fusion devices described herein, according to some embodiments.

[0097] FIG. 35 illustrates one example of an actuator 612 forming part of the expandable fusion device 610 of the present embodiment. By way of example only, the actuator 612 includes a cylindrically shaped elongated shaft having a distal end 624, a proximal end 626, and an anterior-posterior axis extending therebetween. Unlike the actuator 12 described above, the actuator 612 of the present embodiment has a single thread mechanism 628 extending substantially the entire length of the elongated shaft. At least one of the distal and proximal ends 624, 626 is aligned with the anterior-posterior axis and includes a drive mechanism 632 configured to engage an instrument (not shown) to immobilize the actuator 612 while the drive mechanism turns a nut 630. The thread mechanism 628 includes threads disposed on the exterior of the shaft of the actuator 612. By way of example, the thread mechanism 628 can include right-handed threads. Alternatively, the thread mechanism 628 can include left-handed threads. The drive mechanism 632 includes a recessed area configured to receive a drive / holding instrument.

[0098] The recessed area may include a shape that is capable of mating with a corresponding element of an appropriate instrument, including (by way of example only) but not limited to a slot, Phillips, Pozidriv, Friarson, Robertson, 12 point flange, hex socket, safety hex socket, star drive, safety Torx, ta, tri-point, tri-wing, spanner head, clutch, one-way, double square, triple square, polydrive, spline drive, double hex, bristol, pentalobe recess, or any other shaped recess. Alternatively, the drive mechanism 632 may include protrusions (e.g., hex, hexalobular, or square protrusions, or other shaped protrusions) extending longitudinally from the proximal and / or distal end and configured to be coupled to a drive / holding instrument.

[0099] FIG. 36 illustrates (a cross section of) the expandable fusion implant 610 in a fully compressed form. The actuator 612 is positioned such that the distal end 624 is partially threadedly coupled to the threaded opening 640 of the distal wedge 614. The proximal end 626 extends proximally from the proximal wedge 616 and interfaces with the nut 630. The shaft of the actuator 612 extends through the non-threaded opening 656 of the proximal wedge 616 to the distal wedge 614. To effect width expansion of the expandable fusion device 610, an instrument (not shown) is used to engage and lock the actuator 612. The same or a different instrument is then used to rotate the nut 630 (e.g., clockwise for right-handed threads, counterclockwise for left-handed threads). This rotation advances the nut 630 distally along the actuator 612, which presses the proximal wedge 616 against the structure toward the distal wedge 614. The proximal wedge 616 also moves the ramp, which effects the expansion (eg, width only, width first then height, width and height) of the expandable fusion implant 610 without movement of the actuator or the distal wedge 614 .

[0100] Upon completion of the desired deployment, at least a portion of the proximal portion 626 of the actuator 612 will protrude proximally from the proximal wedge 616 (e.g., a proximal overhang), as shown in Figure 37. If desired, the actuator 612 is advanced into the deployment fusion device 610 using an instrument (not shown) that holds the nut 630 in place while the same or a different instrument is used to rotate the actuator (e.g., clockwise for a right-handed thread or counterclockwise for a left-handed thread) to threadably couple the actuator 612 to the distal wedge 614 the desired distance (e.g., Figure 38 illustrates the actuator 612 fully advanced). When the actuator 612 is advanced as desired to minimize the proximal overhang, the locking screw 634 advances into the threaded locking screw opening 635 formed in the wedge 616 adjacent the non-threaded opening 656 so that the locking screw 634 engages the actuator 612 and prevents the proximal wedge 616 from moving relative to the actuator 612, thereby "locking" the wedge 616 (and deployment) in place.

[0101] The expandable fusion device 610 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion devices described herein. Furthermore, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 610.

[0102] Figure 39-4 FIG. 2 illustrates an example of an expandable fusion device 710 for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. By way of example only, the expandable fusion device 710 of this embodiment includes an actuator 712, a distal wedge 714, a proximal wedge 716, a pair of distal ramps 718a, 718b, a pair of proximal ramps 720a, 720b, a plurality of end plates 722a-722d, a plurality of guide pins 723, a locking element 730, and a locking screw 734. As in the previously described embodiment, the distal and proximal wedges 714, 716 are coupled to the actuator 712. The distal ramps 718a, 718b are slidably coupled to the distal wedge 714. The proximal ramps 720a, 720b are slidably coupled to the proximal wedge 716. The plurality of end plates 722a-722d are slidably coupled to the ramps 718a, 718b, 720a, 720b. In general, the expandable fusion device 710 is substantially similar to the expandable fusion device 10 described above, and any / all of the mechanisms described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 710 unless otherwise noted. By way of example only, the expandable fusion device 710 illustrates alternative actuator mechanisms that may be applied to the examples of expandable fusion devices described herein, according to some embodiments.

[0103] By way of example only, the actuator 712 may include a cylindrical elongated shaft having a distal end 724 and a proximal end 726. The distal end 724 is attached to or integral with a distal wedge 714, and the actuator 712 includes a proximal projection from the distal wedge 714. The actuator 712 in this example embodiment does not have a threaded mechanism, but instead is a smooth elongated shaft. The proximal end 726 may include a mating feature 732 (e.g., grooves, ridges, etc.) configured to securely mate with an instrument (not shown).

[0104] Figure 40 shows the fully folded Illustrated is (a cross section of) an expandable fusion implant 710. The proximal end 726 of the actuator 712 extends proximally from the proximal wedge 716 (so that it is accessible to the mating instrument) to secure the mating feature 732 proximal to the unthreaded opening 756 of the proximal wedge 716. The shaft of the actuator 612 extends through the unthreaded opening 756 of the proximal wedge 716 to the distal wedge 714. To effect width deployment of the expandable fusion device 710, a mating instrument (not shown) is used to securely mate with the actuator 712 at the mating feature 723. The same instrument or a different instrument is then used to lock against the proximal wedge 716 to ensure that the proximal wedge 716 does not move during deployment. The instrument is then used to further advance the actuator 712 and pull the distal wedge 714 into the structure toward the proximal wedge 716. The proximal wedge 714 also moves the ramp, which effects the expansion (eg, width only, width first then height, width and height) of the expandable fusion implant 710 without movement of the actuator or the distal wedge 716 .

[0105] Once the desired deployment has been achieved (e.g., FIG. 41), the actuator 712 must be secured with a locking element 730. To facilitate this, the proximal wedge 716 includes a locking element 730 that is at least partially retained within a cross bore 737. The cross bore 737 is configured to retain the locking element 730 (e.g., a ball detent, a pin detent, or other suitable mechanism capable of applying a securing force to the actuator shaft) therein and also expose an unthreaded opening 756 (for contacting the actuator 712) and a locking screw opening 735 (for contacting the locking screw 734) (see, e.g., FIG. 42). Once the desired deployment has been completed, the locking screw 734 is tightened within the locking screw opening 735, which in turn deflects the locking element 730 inwardly and forces the locking element 730 into contact with the actuator 712 to prevent movement of the actuator 712. The locking screw 734 has a tapered nose 739 that can apply an off-axis lateral force to the locking element 730, deflecting or biasing the locking element 730 inwardly. For example, the actuator 712 can have corresponding locking features (e.g., a groove, a series of grooves, serrations, a friction surface, etc.) configured to interact with the locking element 730 to improve resistance to slippage. Additionally, as shown in FIG. 41, at least a portion of the proximal portion 726 of the actuator 712 can protrude proximally from the proximal wedge 716. If desired, the exposed proximal portion of the actuator 712 can be cut away and removed.

[0106] The expandable fusion device 710 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 710.

[0107] 43-48 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 8 illustrates an example of an expandable fusion device 810. By way of example only, the expandable fusion device 810 of this embodiment includes an actuator 812, a distal wedge 814, a proximal wedge 816, a pair of distal ramps 818a, 818b, a pair of proximal ramps 820a, 820b, a plurality of endplates 822a-822d, a plurality of guide pins 823, a locking element 830, and a locking screw 834. As in the previously described embodiment, the distal and proximal wedges 814, 816 are coupled to the actuator 812. The distal ramps 818a, 818b are slidably coupled to the distal wedge 814. The proximal ramps 820a, 820b are slidably coupled to the proximal wedge 816. The plurality of endplates 822a-822d are slidably coupled to the ramps 818a, 818b, 820a, 820b. In general, expandable fusion device 810 is substantially similar to expandable fusion device 10 described above, and any / all of the mechanisms described above with respect to fusion device 10 (and any other fusion devices described herein) may be applied to fusion device 810 unless otherwise noted. By way of example only, expandable fusion device 810 illustrates alternative actuator mechanisms that may be applied to examples of expandable fusion devices described herein, according to some embodiments.

[0108] FIG. 44 shows the present embodiment. 1 illustrates an example of an actuator 812 forming part of a deployable fusion device 810. By way of example only, the actuator 812 may include a cylindrical elongated shaft having a distal end 824, a proximal end 826, and an anterior-posterior axis. The actuator 812 of this example has a thread mechanism 828 near / at the distal end 824. The proximal end 826 includes a drive mechanism 832 aligned with the anterior-posterior axis that is configured to mate with an instrument (not shown) to rotate the actuator 812 and reduce proximal redundancy after deployment, and an engagement mechanism 838 (e.g., grooves, ridges, etc.) configured to positively engage with the instrument (not shown). The thread mechanism 828 includes threads disposed on the exterior of the shaft of the actuator 812. By way of example, the thread mechanism 828 may include right-handed threads. Alternatively, the thread mechanism 828 may include left-handed threads. The drive mechanism 828 includes a recessed area configured to accommodate a drive / holding instrument. Alternatively, the drive mechanism 828 may include a protrusion (e.g., a hexagonal, hexalobular, or square shaped protrusion, or a protrusion of other shape) extending longitudinally from the proximal and / or distal end and configured to be coupled to a drive / holding device.

[0109] Figure 45 shows the fully folded 1 illustrates (in cross section) an expandable fusion implant 810. An actuator 812 is positioned such that a distal end 824 is partially threadedly coupled to a threaded opening 840 in a distal wedge 814. A proximal end 826 of the actuator 812 extends proximally from the proximal wedge 816 to secure the mating feature 736 proximal to an unthreaded opening 856 in the proximal wedge 816 (and thus accessible to a mating instrument). The shaft of the actuator 812 extends through the unthreaded opening 856 in the proximal wedge 816 to the distal wedge 814 and threadably couples to the actuator 812. To effect width deployment of the expandable fusion device 810, a mating instrument (not shown) is used to securely mate with the actuator 812 in the mating feature 836. The same instrument or a different instrument is then used to secure against the proximal wedge 816 to ensure that the proximal wedge 816 does not move during deployment. The instrument is then used to further advance the actuator 812, pulling the distal wedge 814 into the structure towards the proximal wedge 816. The proximal wedge 814 also moves the ramp, thereby effecting expansion (e.g., width only, width first then height, width and height) of the expandable fusion implant 810 without movement of the actuator or the distal wedge 816.

[0110] Desired Upon completion of deployment, as shown in FIG. 46, at least a portion of the proximal portion 826 of the actuator 812 will protrude proximally from the proximal wedge 816 (e.g., proximal overhang). If desired, the actuator 812 is advanced into the deployed fusion device 810 by using a drive device (not shown) to rotate the actuator 812 (e.g., clockwise for right-handed threads, counterclockwise for left-handed threads), thereby threadably coupling the actuator 812 to the distal wedge 814 the desired distance (e.g., FIG. 47 illustrates the actuator 812 fully advanced). Once the actuator 812 has been advanced as desired to reduce or minimize the proximal overhang, the actuator 812 must be secured with a locking element 830. To facilitate this, the proximal wedge 816 includes a locking element 830 that is at least partially retained within a cross bore 837. The cross bore 837 is configured to retain the locking element 830 (e.g., a ball detent, pin detent, or other suitable mechanism capable of applying a locking force to the actuator shaft) therein and also expose an unthreaded opening 856 (for contacting the actuator 812) and a locking screw opening 835 (for contacting the locking screw 834) (see, e.g., FIG. 48). Once the desired deployment is complete, the locking screw 834 is tightened within the locking screw opening 835, which in turn deflects the locking element 830 inwardly and forces the locking element 830 into contact with the actuator 812 to prevent movement of the actuator 812. By way of example, the locking screw 834 may have a tapered nose 839 that may apply an off-axis lateral force to the locking element 830 to deflect or bias the locking element 830 inwardly. For example, the actuator 812 may have a corresponding locking feature 838 (e.g., a groove, a series of grooves, knurling, a friction surface, etc.) configured to interact with the locking element 830 to improve resistance to slippage.

[0111] The expandable fusion device 810 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion devices described herein. Furthermore, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 810.

[0112] 49-53 show a cross-sectional view of a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 9 illustrates an example of an expandable fusion device 910 for use in a fusion procedure. By way of example only, the expandable fusion device 910 of this embodiment includes an actuator 912, a distal wedge 914, a proximal wedge 916, a pair of distal ramps 918a, 918b, a pair of proximal ramps 920a, 920b, a plurality of end plates 922a-922d, and a plurality of guide pins 923. As in the previously described embodiments, the distal and proximal wedges 914, 916 are coupled to the actuator 912. The distal ramps 918a, 918b are slidably coupled to the distal wedge 914. The proximal ramps 920a, 920b are slidably coupled to the proximal wedge 916. The plurality of end plates 922a-922d are slidably coupled to the ramps 918a, 918b, 920a, 920b. In general, the expandable fusion device 910 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to fusion device 10 (and any other fusion device described herein) may be applied to fusion device 910 unless otherwise noted. By way of example only, the expandable fusion device 910 illustrates a pin detent locking mechanism that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0113] 49-53 is substantially identical to actuator 10 described above, and is comprised of a distal end 924, a proximal end 926, and a front-to-rear axis, although the locking mechanisms described herein may be applicable to the other actuator examples described herein, for example, at least one of distal end 924 and proximal end 926 is threaded.

[0114] FIG. 50 illustrates an example of a proximal wedge 916 configured with the locking element 930 of the present embodiment. For example, the locking element 930 of the present embodiment includes a deflecting pin 940 and a locking screw 934. The proximal wedge 916 is substantially similar to the proximal wedge 16 described above. For example, the proximal wedge 916 of this embodiment includes a threaded hole 956 for coupling with the actuator 912 and a locking screw opening 935 adjacent the threaded hole 956. The proximal wedge 916 further includes a cross bore 937 extending through the wedge 916 such that the cross bore 937 intersects the threaded opening 956 and the locking screw opening 935. A pin opening 946 configured to receive a pin 940 therein extends perpendicularly through the proximal wedge 916 such that a pin 940 inserted into the pin opening extends to the intersection of the locking screw opening 935, the cross bore 937, and the screw opening 956.

[0115] For example, pin 940 includes a shaft 942 and a head 944. Preferably, the perimeter of head 944 is greater than the perimeter of shaft 942. Pin 940 is sized and configured relative to a pin opening 946 such that head 944 is received flush within pin opening 946 and shaft 942 is deflected within pin opening 946.

[0116] 51 and 52 show the expandable fusion device 910 of this embodiment in a collapsed and unlocked state. FIG. 53 shows the expandable fusion device 910 of this embodiment in an expanded and locked state. Once the desired deployment is complete, the locking screw 934 is tightened within the locking screw opening 935, which then deflects the shaft 942 of the pin 940 inwardly, forcing the shaft 942 into contact with the actuator 912 to prevent backing out of the actuator 912. By way of example, the locking screw 934 may have a tapered nose 939 that may exert an off-axis lateral force on the pin 940, deflecting or biasing the pin 940 inwardly. For example, the actuator 912 may have a corresponding locking feature (e.g., a groove, a series of grooves, serrations, a friction surface, etc.) configured to interact with the pin 940 to improve resistance to slippage.

[0117] The expandable fusion device 910 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Additionally, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 910.

[0118] 54-56 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1010. By way of example only, the expandable fusion device 1010 of this embodiment includes an actuator 1012, a distal wedge 1014, a proximal wedge 1016, a pair of distal ramps 1018a, 1018b, a pair of proximal ramps 1020a, 1020b, a number of endplates 1022a-1022d, and a number of guide pins. As in the previously described embodiments, the distal and proximal wedges 1014, 1016 are coupled to the actuator 1012. The distal ramps 1018a, 1018b are slidably coupled to the distal wedge 1014. The proximal ramps 1020a, 1020b are slidably coupled to the proximal wedge 1016. The plurality of end plates 1022a-1022d are slidably coupled to the ramps 1018a, 1018b, 1020a, 1020b. In general, the expandable fusion device 1010 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1010 unless otherwise noted. By way of example only, the expandable fusion device 1010 illustrates a ball detent locking mechanism that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0119] 54-56 is substantially identical to actuator 10 described above and includes a distal end 1024, a proximal end 1026, and a front-to-rear axis, although the locking mechanisms described herein may be applicable to the other actuator examples described herein, for example, at least one of distal end 1024 and proximal end 1026 is threaded.

[0120] FIG. 54 illustrates an example of a proximal wedge 1016 configured with the locking element 1030 of this embodiment. For example, the locking element 1030 of this embodiment includes a ball 1040 and a locking screw 1034. The proximal wedge 1016 is substantially similar to the proximal wedge 16 described above. For example, the proximal wedge 1016 of this embodiment includes a threaded hole 1056 for coupling with the actuator 1012 and a locking screw opening 1035 adjacent the threaded opening 1056. The proximal wedge 1016 further includes a cross bore 1037 extending transversely through the wedge 1016 such that the cross bore 1037 intersects with the threaded opening 1056 and the locking screw opening 1035. In particular, the intersection of the cross bore 1037 and the locking screw opening 1035 includes an opening sized to allow only a portion of the ball 1040 to enter the locking screw opening 1035. This ensures that the lockscrew 1034 contacts the ball 1040 and ensures that the ball 1040 does not fall into the lockscrew opening 1035 .

[0121] FIG. 55 illustrates the present embodiment of the expandable fusion device 1010 in a collapsed and unlocked state. FIG. 56 illustrates the present embodiment of the expandable fusion device 1010 in an expanded and locked state. Once the desired deployment is complete, the locking screw 1034 is tightened (or installed and then tightened) within the locking screw opening 1035, which then deflects the ball 1040 inwardly and forces the ball 1040 into contact with the actuator 1012 to prevent backing out of the actuator 1012. By way of example, the locking screw 1034 may have a tapered nose 1039 that may exert an off-axis lateral force on the pin 1040 to deflect or bias the ball 1040 inwardly. For example, the actuator 1012 may have a corresponding locking feature (e.g., a groove, a series of grooves, serrations, a friction surface, etc.) configured to interact with the ball 1040 to improve resistance to slippage.

[0122] The expandable fusion device 1010 of this example embodiment may additionally or alternatively include features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Additionally, any of the additionally described expandable fusion devices may further include features, components, or characteristics of the expandable fusion device 1010.

[0123] 57-65 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1110. By way of example only, the expandable fusion device 1110 of this embodiment includes an actuator 1112, a distal wedge 1114, a proximal wedge 1116, a pair of distal ramps 1118a, 1118b, a pair of proximal ramps 1120a, 1120b, a number of endplates 1122a-1122d, and a number of guide pins. As in the previously described embodiments, the distal and proximal wedges 1114, 1116 are coupled to the actuator 1112. The distal ramps 1118a, 1118b are slidably coupled to the distal wedge 1114. The proximal ramps 1120a, 1120b are slidably coupled to the proximal wedge 1116. The plurality of end plates 1122a-1122d are slidably coupled to the ramps 1118a, 1118b, 1120a, 1120b. In general, the expandable fusion device 1110 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1110 unless otherwise noted. By way of example only, the expandable fusion device 1110 illustrates a spondylolisthesis mitigation configuration that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0124] Spondylolisthesis is a spinal condition that occurs when a vertebral body is displaced (typically in an anterior direction). As described herein, the expandable fusion device 1110 of the present embodiment can help mitigate spondylolisthesis by shifting the upper endplates 1122a, 1122b laterally relative to the lower endplates 1122c and 1122d during height expansion and applying torque to the replaced vertebrae using the fusion device 1110.

[0125] By way of example only, the distal wedge 1114 may be substantially identical to the proximal wedge 14 described above with respect to the device 10. Similarly, the proximal wedge 1116 may be substantially identical to the proximal wedge 16 described above. Alternatively, the distal and proximal wedges 1114 may be identical to one another.

[0126] 60-61 illustrate an example of a second distal ramp 1118b according to this embodiment. By way of example, the distal ramp 1118b may include a distal end 1176, a proximal end 1178, and an inner portion 1180 (e.g., an assembled 11. The second distal ramp 1118b may be configured for slidably coupling with a distal wedge 1114 and / or endplates 1122b, 1122d. The slidable coupling with the wedge 1114 is the same as that described above with respect to the fusion device 10. The second distal ramp 1118b may be configured for slidably coupling with a distal wedge 1114 and / or endplates 1122b, 1122d. The slidable coupling with the wedge 1114 is the same as that described above with respect to the fusion device 10.

[0127] The first lobe 1184 has a sloping structure (e.g., half of a chevron shape from the previous embodiment) with an apex oriented in the proximal direction. The first lobe 1184 includes a top surface 1196, a bottom surface 1198, and a side surface 1199. By way of example, the first lobe 1184 has a generally U-shaped cross-sectional shape, however, it should be noted that the first lobe 1184 may have any suitable cross-sectional shape including, but not limited to (by way of example only), a circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygonal, non-regular polygonal, irregular shape, or combinations thereof. The first lobe 1184 further includes a recessed ramp slot 1202 formed in the side surface 1199 and including a translation stop configured to slidably receive one or more guide pins therein to aid in stabilizing the structure during height deployment. The first lobe 1184 further includes an angled translation surface 1200 on a proximal surface configured to slidably engage the angled surface 1152 of the end plate 22b to facilitate height deployment.

[0128] The second lobe 1186 has a sloping structure (e.g., half of a chevron shape from the previous embodiment) with an apex oriented in the proximal direction. The second lobe 1186 includes a top surface 1197, a bottom surface 1198, and a side surface 1205. By way of example, the second lobe 1186 has a generally U-shaped cross-sectional shape, however, it should be noted that the second lobe 1186 may have any suitable cross-sectional shape including, but not limited to (by way of example only), a circular, oval, elliptical, triangular, rectangular, T-shaped, V-shaped, regular polygonal, non-regular polygonal, irregular shape, or combinations thereof. The second lobe 1186 further includes a recessed ramp slot 1203 formed in the side surface 1203 and including a translation stop configured to slidably receive one or more guide pins therein to aid in stabilizing the structure during height deployment. The second lobe 1186 further includes an angled translation surface 1201 on a proximal surface configured to slidably engage the angled surface 1156 of the end plate 22b to facilitate height deployment.

[0129] By way of example, the bottom surface 1198 is functionally similar to the L-shaped cutting surface 500 described above (and essentially forms an L-shape with the vertical post 1206), i.e., the bottom surface 1198 is configured to slidably engage a corresponding surface of the second proximal ramp 1120b.

[0130] By way of example, the distal end 1176 includes tongue and groove connectors 1188c, 1188d that slidably engage corresponding tongue and groove connectors on the distal wedge 1114. The distal end 1176 also includes a vertical post 1206 that includes a vertical protrusion 1208 configured to facilitate height deployment.

[0131] For example, various end plates 1122a 1122d are identical or identical mirror images of one another, and therefore only one of the endplates needs to be described in more detail. Figure 62 illustrates one example of an endplate 1122b of the present disclosure. By way of example only, endplate 1122b has a first (e.g., distal) end 1138 and a second (e.g., proximal) end 1140.

[0132] The end plate 1122b further includes a first angled slot 1146 proximate the first end 1138, a second angled slot 1148 located near the first angled slot 1146, and a vertical channel 1150 located near the second end 1140. Optionally, in any manner, the angle or shape of the angled slots 1146, 1148 may be equal or different. The first angled slot 1146 has an angled surface 1152 that is generally transverse to the anterior-posterior axis of the implant. The first angled slot 1146 is sized and configured to slidably receive at least a portion of the first lobe 1184 of the second distal ramp 1118b such that the angled translation surface 1200 of the first lobe 1184 slidably engages the angled surface 1152. The second angled slot 1148 has an angled surface 1156 that is generally transverse to the anterior-posterior axis of the implant. The second angled slot 1148 is sized and configured to slidably receive at least a portion of the second lobe 1186 of the second distal ramp 1118b such that the angled translation surface 1201 of the second lobe 1186 is in slidable engagement with the angled surface 1156. Thus, after width deployment is completed, as the distal wedge 1114 advances the distal ramp 1118b toward the proximal wedge 1116 (and the proximal ramp 1120b), the endplate 1122b is vertically displaced (resulting in height deployment) due in part to angular translation along the angled surface 152.

[0133] The vertical passage 1150 has a size and shape corresponding to the size and shape of the vertical post of the second proximal ramp 1120b, which is identical or a mirror image of the vertical post 1206 of the distal ramp 1118b, as described below, and is an end plate relative to the proximal ramp 1120b. The vertical passage 1150 is configured to facilitate vertical translation of the lower endplates 1122c, 1122d relative to the distal ramps 1118a, 1118b and diagonally relative to the proximal ramps 1120a, 1120b. The upper endplates 1122a, 1122b translate vertically relative to the proximal ramps 1120a, 1120b and diagonally relative to the distal ramps 1118a, 1118b. The vertical passage 1150 further includes a vertical recess 1151 sized and shaped to accommodate the vertical protrusion 1208 (or a mirror image equivalent thereof). Thus, in this embodiment, the lower endplates 1122c, 1122d translate vertically relative to the distal ramps 1118a, 1118b and diagonally relative to the proximal ramps 1120a, 1120b. The upper endplates 1122a, 1122b translate vertically relative to the proximal ramps 1120a, 1120b and diagonally relative to the distal ramps 1118a, 1118b.

[0134] As an example, at least two of the first distal lamp 1118a, the second distal lamp 1118b, the first proximal lamp 1120a, and the second proximal lamp 1120b are identical. Furthermore, at least two of the first distal lamp 1118a, the second distal lamp 1118b, the first proximal lamp 1120a, and the second proximal lamp 1120b have mirror image equivalents. For example, in this embodiment, the first distal lamp 1118a is identical to the second proximal lamp 1120b, the second distal lamp 1118b is identical to the first proximal lamp 1120a, the first and second distal lamps 1118a, 1118b have mirror image equivalents, and the first and second proximal lamps 1120a, 1120b have mirror image equivalents. Similarly, by way of example only, at least two of the end plates 1122a, 1122b, 1122c, 1122d are identical and at least two of the end plates 1122a, 1122b, 1122c, 1122d are mirror image equivalents.

[0135] 63-65 show the relationship between height spread and horizontal endplate displacement according to some embodiments. By way of example, FIG. 63 shows the relationship between height spread H 0 and horizontal displacement d 0 FIG. 64 shows a fully collapsed implant with height expansion H 1 After horizontal displacement d 1 Similarly, Figure 65 shows that the height expansion H 2 is the horizontal displacement d2 It is shown that the result of the specific height expansion H n Horizontal displacement d n The exact value of may vary depending on the angle of the inclined translation surfaces on the ramp and end plates. Increasing the acute angle results in a larger horizontal displacement.

[0136] The expandable fusion device 1110 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1110.

[0137] 66-69 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1210. By way of example only, the expandable fusion device 1210 of this embodiment includes an actuator 1212, a distal wedge 1214, a proximal wedge 1216, a pair of distal ramps 1218a, 1218b, a pair of proximal ramps 1220a, 1220b, a number of end plates 1222a-d, and a number of guide pins (optionally). As in the previously described embodiment, the distal and proximal wedges 1214, 1216 are coupled to the actuator 1212. The distal ramps 1218a, 1218b are slidably coupled to the distal wedge 1214. The proximal ramps 1220a, 1220b are slidably coupled to the proximal wedge 1216. The plurality of end plates 1222a-1222d are slidably coupled to the ramps 1218a, 1218b, 1220a, 1220b. In general, the expandable fusion device 1210 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1210 unless otherwise noted. By way of example only, the expandable fusion device 1210 illustrates a spondylolisthesis mitigation configuration that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0138] Vertebral rotation is a spinal disorder that occurs when vertebral bodies rotate out of alignment, for example in scoliosis patients. As described herein, the expandable fusion device 1210 of the present embodiment can help achieve derotation by horizontally shifting upper and lower endplates (e.g., endplates 1222a, 1222c and endplates 1212b, 1212d) on the same side relative to each other during height expansion and applying torque to the replaced vertebrae using the fusion device 1210.

[0139] In this embodiment, the actuator 1212, the distal wedge 1214, and the proximal wedge 1216 are identical or substantially similar to the corresponding parts described in the previous embodiment. By way of example, the distal ramps 1218a, 1218b and the proximal ramps 1220b, 1220b are identical to each other except for any dovetail connectors, which will be described in further detail below. By way of example, the ramps 1218a, 1218b, 1220a, 1220b are identical in form and function (except for the dovetail connectors) to the second distal ramp 1118b described above. Furthermore, because the ramps 1218a, 1218b, 1220a, 1220b are identical, the end plates 1222a, 1222b, 1222c, 1222d are also identical. This reduces the number of different parts required during assembly. By way of example, end plates 1222a, 1222b, 1222c, 1222d are identical to end plate 1122b described above.

[0140] By way of example, Figure 66 shows the expandable fusion device 1210 of this embodiment in a fully collapsed state. Figure 67 shows the expandable fusion device 1210 in a full width expanded state. At this point, the endplates 1222a, 1222b, 1222c, 1222d have not been horizontally displaced. Figure 68 shows the expandable fusion device 1210 in its full width and height expanded state. As can be seen, the first upper endplate 1222a and the second lower endplate 1222d are displaced proximally, and the second upper endplate 1222b and the first lower endplate 1222c are displaced distally.

[0141] 69 shows an example of a second distal and proximal ramps 1218b, 1220b equipped with dovetail connectors such that the expandable fusion device 1210 maintains structural integrity during torsional forces imposed on the vertebrae (and counter-torsion forces imposed on the device 1210 by the vertebrae). In this embodiment, the distal ramp 1218b includes an elongated dovetail flange 1250 extending along a smooth bottom surface 1298a. The proximal ramp 1220b includes a complementary dovetail groove 1252 formed in the bottom surface 1298b. The elongated dovetail flange 1250 is slidably coupled to the dovetail groove 1252, allowing axial movement but not other relative movement (e.g., rotational movement, etc.) between the distal and proximal ramps 1218b, 1220b.

[0142] The expandable fusion device 1210 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1210.

[0143] 70-75 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1310. By way of example only, the expandable fusion device 1310 of this embodiment includes an actuator 1312, a distal wedge 1314, a proximal wedge 1316, a pair of distal ramps 1318a, 1318b, a pair of proximal ramps 1320a, 1320b, a number of end plates 1322a-1322d, and a number of guide pins 1323. As in the previously described embodiments, the distal and proximal wedges 1314, 1316 are coupled to the actuator 1312. The distal ramps 1318a, 1318b are slidably coupled to the distal wedge 1314. The proximal ramps 1320a, 1320b are slidably coupled to the proximal wedge 1316. The plurality of end plates 1322a-1322d are slidably coupled to the ramps 1318a, 1318b, 1320a, 1320b. In general, the expandable fusion device 1310 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1310 unless otherwise noted. By way of example only, the expandable fusion device 1310 illustrates a width stabilizer that may be applied to any example expandable fusion device described herein, according to some embodiments.

[0144] Referring first to FIG. 73, an example of a width stabilizer 1340 is shown. By way of example only, the width stabilizer 1340 of this example includes a first crossbar 1342 vertically separated from a second crossbar 1344 by a mating element 1346. The first and second crossbars 1344 can have any cross-sectional shape that ensures that the end plates 1322a-1322d are generally parallel to one another during width deployment, including, but not limited to, oval, rectangular, trapezoidal, polygonal, and the like. The mating element 1346 can include a structural element that can align the width stabilizer 1340 to the actuator 1312. By way of example only, the mating element 1346 of this embodiment includes a ring member having a threaded opening 1348 extending therethrough. The threaded opening 1348 is sized and configured to allow the actuator 1312 to pass therethrough.

[0145] 70-75, each of the end plates 1322a-1322d has a side opening 1350 formed therethrough that extends perpendicular to the front-to-rear axis of the end plate, the side opening 1350 being configured to accommodate at least a portion of the first or second crossbar 1342, 1344. By way of example, the side openings 1350 are located at the midpoint of each end plate, although this location may vary depending on the number of width stabilizers being used and the ramp configuration of the particular embodiment being used. As shown in FIGS. 70 and 74, the side openings 1350 are sized and shaped to closely accommodate the crossbars 1342, 1344 without any rocking motion. This close interaction maintains the end plates 1322a-1322d in a parallel orientation during width deployment. Once width expansion is complete as shown in Figures 71 and 75, the first and second crossbars 1342, 1344 are no longer interlocked within the side openings 1350 and height expansion is no longer inhibited (eg, Figure 72).

[0146] The expandable fusion device 1310 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1310.

[0147] 76-80 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1410. By way of example only, the expandable fusion device 1410 of this embodiment includes an actuator 1412, a distal wedge 1414, a proximal wedge 1416, a pair of distal ramps 1418a, 1418b, a pair of proximal ramps 1420a, 1420b, a number of end plates 1422a-d, and a number of guide pins 1423. As in the previously described embodiment, the distal and proximal wedges 1414, 1416 are coupled to the actuator 1412. The distal ramps 1418a, 1418b are slidably coupled to the distal wedge 1414. The proximal ramps 1420a, 1420b are slidably coupled to the proximal wedge 1416. The plurality of end plates 1422a-1422d are slidably coupled to the ramps 1418a, 1418b, 1420a, 1420b. In general, the expandable fusion device 1410 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1410 unless otherwise noted. By way of example only, the expandable fusion device 1410 illustrates a width stabilizer that may be applied to other examples of any of the expandable fusion devices described herein, according to some embodiments.

[0148] Referring first to FIG. 77, an example of a width stabilizer 1440 is shown. By way of example only, the width stabilizer 1440 of this example includes a cross bar 1442 and a mating element 1446. The cross bar 1442 can have any cross-sectional shape that ensures that the end plates 1422a-1422d are generally parallel to one another during width deployment, including, but not limited to, an ellipse, a rectangle, a trapezoid, a polygon, and the like. The mating element 1446 can include any structural element that can align the width stabilizer 1440 to the actuator 1412. By way of example only, the mating element 1446 of this embodiment includes a half ring member having an arcuate surface 1448 configured to mate with the actuator 1412.

[0149] 76-80, each of the end plates 1422a-1422d has a side opening 1450 formed therethrough that extends perpendicular to the front-to-rear axis of the end plate, the side opening 1450 being configured to accommodate at least a portion of the cross bar 1442. By way of example, the side opening 1450 is located at the midpoint of each end plate, although this location may vary depending on the number of width stabilizers being used and the ramp configuration of the particular embodiment being used. Because the width stabilizer 1440 is a single cross bar, a pair of width stabilizers 1440 are used in this embodiment to keep the end plates parallel during width deployment. As shown in FIGS. 78-79, the side opening 1450 is sized and shaped to closely accommodate the cross bar 1442 without any rocking motion. This close interaction maintains the end plates 1422a-1422d in a parallel orientation during width deployment. The width stabilizer 1440 in this example is not attached to the actuator 1412 as in the previous embodiment of the device 1310 and therefore does not impede height deployment at any time (see, e.g., FIG. 79). As shown in FIG. 80, at least a portion of the crossbar 1442 may remain engaged within the side opening 1450 even after width deployment is complete.

[0150] The expandable fusion device 1410 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1410.

[0151] 81-84 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1510. By way of example only, the expandable fusion device 1510 of this embodiment includes an actuator 1512, a distal wedge 1514, a proximal wedge 1516, a pair of distal ramps 1518a, 1518b, a pair of proximal ramps 1520a, 1520b, a number of end plates 1522a-d, and (optionally) a number of guide pins. As in the previously described embodiment, the distal and proximal wedges 1514, 1516 are coupled to the actuator 1512. The distal ramps 1518a, 1518b are slidably coupled to the distal wedge 1514. The proximal ramps 1520a, 1520b are slidably coupled to the proximal wedge 1516. The plurality of end plates 1522a-1522d are slidably coupled to the ramps 1518a, 1518b, 1520a, 1520b. In general, the expandable fusion device 1510 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1510 unless otherwise noted. By way of example only, the expandable fusion device 1510 illustrates a width stabilizer that may be applied to other examples of any of the expandable fusion devices described herein, according to some embodiments.

[0152] Referring first to FIG. 84, an example of a width stabilizer 1540 is shown. By way of example only, the width stabilizer 1540 of this example includes a cross bar 1542 and a mating element 1546. The cross bar 1542 can have any cross-sectional shape that ensures that the end plates 1522a-1522d are generally parallel to one another during width deployment, including, but not limited to, oval, rectangular, trapezoidal, polygonal, and the like. For example, the cross bar 1542 includes a pair of angled struts 1544 in a general chevron shape with an apex in the distal direction. The angled struts 1544 allow the strut components and the mating element 1546 to be centered between the end plates in embodiments having a ramp configuration that eliminates straight struts at the midline. Additionally, the angled struts 1544 prevent the struts 1544 from dislodging from the side openings 1550 during height deployment. The mating element 1546 may include any structural element capable of aligning the width stabilizer 1540 with the actuator 1512. By way of example only, the mating element 1546 in this embodiment includes a half-ring member having an arcuate surface 1548 configured to mate with the actuator 1512.

[0153] 81-84, each of the end plates 1522a-1522d has a side opening 1550 formed therethrough that extends at an oblique angle relative to the anterior-posterior axis of the end plate, the side opening 1550 being configured to accommodate at least a portion of the cross bar 1542 (e.g., FIG. 83). By way of example, the side opening 1550 is located proximal to the midpoint of each end plate but at an angle relative to the centerline of the device 1510, although this location may vary depending on the number of width stabilizers being used and the ramp configuration of the particular embodiment being used. Because the width stabilizer 1540 is a single cross bar, a pair of width stabilizers 1540 are used in this embodiment to keep the end plates parallel during width deployment. As shown in FIGS. 81 and 83, the side opening 1550 is sized and shaped to closely accommodate the cross bar 1542 without any rocking motion. This close interaction maintains the end plates 1522a-d in a parallel orientation during width deployment. The width stabilizer 1540 in this example is not attached to the actuator 1512, as in the device 1310 described above, and therefore does not impede height deployment at any time. As shown in FIG. 83, at least a portion of the crossbar 1542 may remain engaged within the side opening 1550 even after width deployment is complete.

[0154] The expandable fusion device 1510 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1510.

[0155] 85-88 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1610. By way of example only, the expandable fusion device 1610 of this embodiment includes an actuator 1612, a distal wedge 1614, a proximal wedge 1616, a pair of distal ramps 1618a, 1618b, a pair of proximal ramps 1620a, 1620b, a number of end plates 1622a-1622d, and a number of guide pins 1623. As in the previously described embodiments, the distal and proximal wedges 1614, 1616 are coupled to the actuator 1612. The distal ramps 1618a, 1618b are slidably coupled to the distal wedge 1614. The proximal ramps 1620a, 1620b are slidably coupled to the proximal wedge 1616. The plurality of end plates 1622a-1622d are slidably coupled to the ramps 1618a, 1618b, 1620a, 1620b. In general, the expandable fusion device 1610 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1610 unless otherwise noted. By way of example only, the expandable fusion device 1610 illustrates a width stabilizer that may be applied to other examples of any of the expandable fusion devices described herein, according to some embodiments.

[0156] 86, there is shown one example of a width stabilizer 1640. By way of example only, the width stabilizer 1640 in this example includes a single linear crossbar 1640 with a pair of lateral flanges 1644 disposed on either end of the crossbar 1642. The crossbar 1642 can have any cross-sectional shape that ensures that the end plates 1622a-1622d are generally parallel to one another during width deployment, including, but not limited to, oval, rectangular, trapezoidal, polygonal, etc.

[0157] 85-88, each of the end plates 1622a-d has a side opening 1650 formed therethrough that extends perpendicular to the front-to-rear axis of the end plate and is configured to receive at least a portion of the cross bar 1642. The inner opening of the opening 1650 has a translation stop 1652 that interacts with the flange 1644 to prevent the cross bar 1642 from exiting the opening 1650. The translation stop 1642 not only prevents disassembly, but also functions to limit width expansion. One or more flanges 1644 may be formed after assembly by, for example, bending, pressing, welding, or attaching flanges 1644 to the ends of the cross bar 1642 to allow insertion of the cross bar 1642 into the side opening 1650 (e.g., through the translation stop 1652). Alternatively, during assembly of the expandable fusion device 1610, at least one lateral flange 1644 may partially contract to allow insertion of the crossbar 1642 into the side opening 1650 of the endplates 1622a-1622d. By way of example, the side opening 1650 is located at the midpoint of each endplate, although this location may vary depending on the number of width stabilizers used and the ramp configuration of the particular embodiment being used. Because the width stabilizer 1640 is a single crossbar, a pair of width stabilizers 1640 is used in this embodiment to keep the endplates parallel during width deployment. The side opening 1650 is sized and shaped to closely accommodate the crossbar 1642 without any rocking motion. This close interaction maintains the endplates 1622a-1622d in a parallel orientation during width deployment. The width stabilizer 1640 in this example is not attached to the actuator 1612, as in device 1310 described above, and therefore does not impede height deployment at any time.

[0158] The expandable fusion device 1610 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1610.

[0159] 89-99 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1710. By way of example only, the expandable fusion device 1710 of this embodiment includes an actuator 1712, a distal wedge 1714, a proximal wedge 1716, a pair of distal ramps 1718a, 1718b, a pair of proximal ramps 1720a, 1720b, a number of end plates 1722a-1722d, and a number of guide pins 1723. As in the previously described embodiment, the distal and proximal wedges 1714, 1716 are coupled to the actuator 1712. The distal ramps 1718a, 1718b are slidably coupled to the distal wedge 1714. The proximal ramps 1720a, 1720b are slidably coupled to the proximal wedge 1716. The plurality of end plates 1722a-1722d are slidably coupled to the ramps 1718a, 1718b, 1720a, 1720b. In general, the expandable fusion device 1710 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1710 unless otherwise noted. By way of example only, the expandable fusion device 1710 illustrates a width stabilizer that may be applied to other examples of any of the expandable fusion devices described herein, according to some embodiments.

[0160] By way of example only, the width stabilizer 1750 of this example includes interdigitated protrusions 1750 that extend inwardly from one endplate and nest into grooves 1752 of another endplate. For example, FIGS. 89-91 and 93-94 show an expandable fusion device 1710 having a single protrusion 1750b formed on the outer contact surface 1742 of the second upper endplate 1722b and extending inwardly toward the first upper endplate 1722a. The single protrusion 1750b is received within a complementary groove 1752a formed in the outer contact surface 1742 of the first upper endplate 1722a, allowing single-axis translation of the protrusion 1750b within the groove 1752a. At the same time, the first upper endplate 1722a has a pair of protrusions 1750a that extend inwardly toward the second upper endplate 1722b. The protrusions 1750a are received within complementary grooves 1752b formed in the outer contact surface 1742 of the second upper endplate 1722b, allowing single-axis translation of the protrusions 1750a within the grooves 1752b. The protrusions 1750a extend on either side of the protrusions 1750b and are in flush, slidable contact with the protrusions 1750b. The grooves 1752b are located on either side of the protrusions 1750b of the second upper endplate 1722b. The flush contact between the protrusions, along with the nesting of the protrusions 1750 within the grooves 1752, maintains the endplates in a parallel orientation during width expansion. In some embodiments, to maximize (among other things) the healing volume, the interdigitating protrusions 1750 and, optionally, the complementary grooves 1752 are present only on one set of endplates (the upper or lower set) and not on the other.

[0161] According to this embodiment, the expandable fusion implant 1710 may be provided with any number of interdigitating protrusions 1750 without departing from the scope of the present disclosure. For example, FIG. 92 illustrates an expandable fusion implant 1710 having two or more protrusions 1750 extending from each endplate 1722a, 1722b. By way of example only, the expandable fusion implant 1710 of FIG. 92 includes five protrusions 1750a extending from a first upper endplate 1722a that interdigitate with four protrusions 1752b extending from a second upper endplate 1722b. Thus, the first upper endplate 1722a includes four complementary grooves 1752a and the second upper endplate 1722b includes five complementary grooves 1752b.

[0162] The protrusions 1750 and grooves 1752 can have any cross-sectional shape that ensures that the end plates 1722a-1722d are generally parallel to one another during width deployment, including, but not limited to, square, rectangular, trapezoidal, polygonal, and the like. Additionally, the protrusions 1750 and grooves 1752 can have a dovetail interlocking. FIGS. 95-99 show some examples of protrusion interactions. By way of example only, FIG. 95 shows an embodiment in which protrusion 1750b has a "+" shaped dovetail and protrusion 1750a has a corresponding elongated recess to accommodate the dovetail. FIG. 96 shows an example embodiment in which protrusion 1750b has a "T" shaped dovetail and protrusion 1750a has a corresponding elongated recess to accommodate the dovetail. FIG. 97 shows an example of FIGS. 89-91 and 93-94 in which protrusions 1750a and 1750b simply interfit. 98 shows an example where protrusion 1750a includes a bridge 1754 which includes protrusion 1750b. FIG. 99 shows an interdigitated version of the embodiment of FIG.

[0163] The expandable fusion device 1710 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1710.

[0164] 100-105 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 1810. By way of example only, the expandable fusion device 1810 of this embodiment includes an actuator 1812, a distal wedge 1814, a proximal wedge 1816, a pair of distal ramps 1818a, 1818b, a pair of proximal ramps 1820a, 1820b, a number of end plates 1822a-d, and a number of optional guide pins 1823. As in the previously described embodiment, the distal and proximal wedges 1814, 1816 are coupled to the actuator 1812. The distal ramps 1818a, 1818b are slidably coupled to the distal wedge 1814. The proximal ramps 1820a, 1820b are slidably coupled to the proximal wedge 1816. The plurality of end plates 1822a-1822d are slidably coupled to the ramps 1818a, 1818b, 1820a, 1820b. In general, the expandable fusion device 1810 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1810 unless otherwise noted. By way of example only, the expandable fusion device 1810 illustrates an expandable fusion device having a width expanded and lordotic expansion that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0165] By way of example, the actuator 1812, distal wedge 1814, and proximal wedge 1816 may be the same as or substantially similar to corresponding elements disclosed with respect to other embodiments herein.

[0166] 103 illustrates an example of a distal ramp 1818b according to this embodiment. By way of example only, the distal ramp 1818b has a proximal end 1840, a distal end 1842, an inner surface 1844, a side surface 1846, an upper portion 1848, and a lower portion 1850. The upper and lower portions 1848, 1850 each have a tongue and groove connector 1852 on their distal sides. , configured to slidably interact with a corresponding tongue and groove connector of the distal wedge 1814, as described above. The upper and lower portions 1848, 1850 each have a translation member 1854 at a proximal lateral angle of the distal ramp 1818b. By way of example only, the translation members 1854 are each generally circular and have a generally planar outwardly facing surface 1856 and an arcuate translation surface 1858. The generally planar outwardly facing surface 1856 is configured to nest within a first opening 1894 of the endplate 1822 when the expandable fusion device 1810 is in a fully collapsed state (e.g., to minimize the height dimension of the collapsed implant for insertion). The translation surface 1856 is configured to slidably engage an angled slot 1886 of an endplate (e.g., endplate 1822b) and further translates along the angled slot 1886 during lordotic deployment. Optionally, at least one translation member 1854 may have a guide pin opening 1859 for accommodating a guide pin 1823. The guide pin acts as a lordosis deployment limiter, as the guide pin 1823 stops lordosis deployment when the guide pin 1823 reaches the end of the ramp groove 1888.

[0167] FIG. 104 illustrates an example of a second distal ramp 1820b according to an example embodiment. By way of example only, the proximal ramp 1820b has a distal end 1860 and a proximal end 1862. The proximal ramp 1820b includes at least one (e.g., a first) arcuate ramp 1864 and optionally includes a second (or more) arcuate ramp 1866 (shown by way of example only) disposed distally of the first arcuate ramp 1864. The ramps 1864, 1868 are curved along concentric circular arcs having a center point in the proximal direction. The arcuate ramps 1864, 1866 are configured to slidably mate with the first and second arcuate channels 1890, 1892, respectively, of the corresponding endplates 1822 (e.g., 1822b, 1822d). By way of example, the arcuate ramps 1864, 1866 primarily function as pivot guides during lordotic deployment, but also serve to hold the deployment angle in place once lordotic deployment is complete. Each arcuate ramp 1864, 1866 has a pair of outwardly facing flats 1870, 1872, respectively, that are configured to nest within the first openings 1896, 1898 of the endplates 1822 when the expandable fusion device 1810 is in a fully collapsed state (e.g., minimizing the height dimension of the collapsed implant for insertion). The proximal end 1862 has a pair of tongue and groove connectors 1868 that are configured to slidably interact with corresponding tongue and groove connectors on the distal wedge 1816, as described above.

[0168] The relevant endplate structure will now be described with particular reference to Figures 100 and 105. By way of example, endplate 1822a will be described, however it should be understood that each endplate is identical to endplate 1822a (e.g., 1822d) or is a mirror image equivalent (e.g., endplates 1822b, 1822c) and the elements described are implicitly included in each endplate. By way of example only, endplate 1822a has a distal end 1880, a proximal end 1882, and an outer vertebral contacting surface 1884. An angled groove 1886 is formed in a distal portion of endplate 1822a, intersects outer contacting surface 1884 (e.g., at opening 1894), and angles proximally therefrom. Angled groove 1886 is configured to slidably receive translation member 1854 of distal ramp 1818a to facilitate lordotic deployment. Angled groove 1886 may further include an optional ramp groove 1888 that slidably receives guide pin 1823. The proximal portion of endplate 1822a includes at least one arcuate channel 1890 (depending on the number of arcuate ramps, as discussed above), and in this example also includes a second arcuate channel 1892. The arcuate channels are oriented in concentric arcs having a center point in the proximal direction and each intersects the outer contact surface 1884 at an opening (e.g., openings 1896, 1898). The arcuate channels 1890, 1892 are configured to slidably engage the first and second arcuate ramps 1864, 1866, respectively, of the corresponding proximal ramps 1820a, 1820b, as described above. Thus, the arcuate shape of the arcuate channels 1890, 1892 is equal to the arcuate shape of the respective arcuate ramps 1864, 1866.

[0169] In operation, a first width deployment is proceeded substantially as described above for the previous embodiment. That is, the actuator 1812 is rotated a selected number of actuations until some width deployment is reached and the endplate disengages from the distal wedge 1814. Once disengagement occurs, further rotation of the actuator 1812 causes the distal ramps 1818a, 1818b to translate along the respective angled grooves of the endplate, increasing at least one of the width, height, and lordosis angle in the process. That is, actuation of the drive mechanism a first number of actuations in a first actuation direction deploys at least some width. Actuation of the drive mechanism a second number of actuations beyond the first number of actuations in the first actuation direction then increases at least one of the width, height, and lordosis angle.

[0170] The expandable fusion device 1810 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1810.

[0171] 106-113 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates one example of an expandable fusion device 1910. By way of example only, the expandable fusion device 1910 of this embodiment includes an actuator 1912, a distal wedge 1914, a proximal wedge 1916, a pair of distal ramps 1918a, 1918b, a pair of proximal ramps 1920a, 1920b, a number of endplates 1922a-d, and a number of guide pins. As in the previously described embodiments, the distal and proximal wedges 1914, 1916 are coupled to the actuator 1912. The distal ramps 1918a, 1918b are slidably coupled to the distal wedge 1914. The proximal ramps 1920a, 1920b are slidably coupled to the proximal wedge 1916. The plurality of end plates 1922a-1922b are slidably coupled to the ramps 1918a, 1918b, 1920a, 1920b. In general, the expandable fusion device 1910 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 1910 unless otherwise noted. By way of example only, the expandable fusion device 1910 illustrates a lateral lordotic deployment feature that may be applied to any of the expandable fusion device examples described herein, according to some embodiments. By way of example only, the expandable fusion device 1910 of this embodiment has a posterior side 1936 and an anterior side 1934.

[0172] The expandable fusion implant 1910 is configured to have a preselected lateral lordosis angle ∂1 in the fully collapsed position such that when the implant 1910 is initially inserted into the intervertebral space, the lordosis angle ∂1 of the implant aligns with the lordosis of the spine (e.g., FIG. 110). Also, note that the lateral contact surfaces of the superior endplates 1922a, 1922b and the lateral contact surfaces of the inferior endplates 1922c, 1922d may be generally coplanar in the plane defined by the lordosis angle ∂1. This is accomplished by making the posterior pair of endplates (e.g., endplates 1922b, 1922d) thicker than the anterior pair of endplates (e.g., endplates 1922a, 1922c) such that the posterior side of the implant has a greater height than the anterior side. However, a challenge that arises with expandable implants is that during width expansion, as the posterior endplate moves away from the anterior endplate, the lordotic angle of the implant decreases and the associated external contact surfaces are no longer coplanar. If the height of the endplates were to increase at the same rate, subsequent height expansion would not solve the problem. To solve this problem, the present example expandable fusion device 1910 allows the posterior pair of endplates (e.g., 1922b, 1922d) to expand to a height (h) sufficient to re-establish the desired lordotic angle ∂1. 1 ) (e.g., FIG. 112), and delays the height development of the anterior pair of endplates (e.g., 1922b, 1922c) until the lateral contact surfaces of the upper and lower endplate pairs are aligned. Once this condition occurs, the anterior pair of endplates 1922a, 1922c will develop in height at the same rate as the posterior pair of endplates 1922b, 1922d while still maintaining the desired lordosis angle ∂1. Thus, the maximum height development (h 2 ) is the maximum height expansion (h 3 ) (e.g., Figure 113 ).

[0173] By way of example, the actuator 1912, distal wedge 1914, proximal wedge 1916, distal ramps 1918a, 1918b, and proximal ramps 1920a, 1920b may be identical to or substantially similar to corresponding elements described herein with respect to other embodiments, and therefore, except where necessary, their specific structure will not be described.

[0174] By way of example, the endplates include rear endplates 1922c, 1922d and front endplates 1922a, 1922c. Endplate 1922c is identical or mirror equivalent to endplate 1922a and has the same elements, so endplate 1922a will be described here as representative of the front endplates. By way of example, first front endplate 1922a has a distal end 1930, a proximal end 1932, an outer contact surface 1937a, and a number of angled grooves (not shown, but the same or similar as described above) that interact with the angled surfaces of distal and proximal ramps 1918a, 1920a (not shown, but the same or similar as described above) to facilitate height deployment in the same manner as described above with respect to other embodiments. By way of example only, in this embodiment, the plurality of angled grooves includes a first distal angled groove intersecting the outer contact surface 1937a at a first distal opening 1946a, a second distal angled groove intersecting the outer contact surface 1937a at a first distal opening 1948a, a first proximal angled groove intersecting the outer contact surface 1937a at a first proximal opening 1950a, and a second proximal angled groove intersecting the outer contact surface 1937a at a second proximal opening 1952a. Prior to height deployment (regardless of width deployment), relevant portions of the distal ramp 1918a (e.g., first and second lobes) are flush against the angled surface of the end plate 1922a, and height deployment may commence as soon as the end plate 1922a separates from the wedges 1914, 1916.

[0175] By way of example, endplate 1922d is identical or mirror equivalent to endplate 1922b and has the same elements, so endplate 1922b will be described herein as representative of the rear endplate. By way of example, first rear endplate 1922b has a distal end 1930, a proximal end 1932, an outer contact surface 1937b, and a number of angled grooves (not shown, but the same or similar as described above) that interact with the angled surfaces of distal and proximal ramps 1918b, 1920b (not shown, but the same or similar as described above) to facilitate height deployment in the same manner as described above with respect to other embodiments. By way of example only, in this embodiment, the plurality of angled grooves includes a first distal angled groove intersecting the outer contact surface 1937b at a first distal opening 1946b, a second distal angled groove intersecting the outer contact surface 1937b at a first distal opening 1948b, a first proximal angled groove intersecting the outer contact surface 1937b at a first proximal opening 1950b, and a second proximal angled groove intersecting the outer contact surface 1937b at a second proximal opening 1952b. Prior to height deployment (regardless of width deployment), an associated portion of the distal ramp 1918a (e.g., first and second lobes) is spaced apart from the angled surface of the endplate 1922b by a gap 1954, and height deployment may be delayed until the endplate 1922a reaches a sufficient height to restore the lordotic angle of the device 1910. The gap 1954 allows the front ramps 1918b, 1920b to translate at the same rate as the rear ramps 1918a, 1920a, but the ramps must cross the gap 1954 before the ramps' angled surfaces engage the end plate's angled surfaces. When that happens, the rear side 1936 height expansion occurs.

[0176] Due to the elongated endplates of a laterally deploying fusion device, vertical stabilization features may be required to ensure center alignment of the implant during deployment. By way of example, FIG. 109 illustrates an example of first and second vertical stabilizers 1960, 1970 used in the deployable fusion device 1910 of this embodiment. By way of example, the first vertical stabilizer 1960 includes a post 1962 associated with the upper posterior endplate 1922a that extends vertically toward the lower posterior endplate 1922c and is received within a vertical channel 1944 formed within the endplate 1922c. By way of example only, the post 1962 is inseparably associated with the endplate 1922a and slidably interlocks with the channel 1964 (e.g., molded in one piece, press-fit, or secured within a corresponding recess). The posts 1962 and corresponding channels 1964 may have any cross-sectional shape capable of maintaining passage, including, but not limited to, circular, oval, elliptical, square, polygonal, irregular, etc. In some aspects, the positions of the posts 1962 and channels 1964 may be reversed, with the posts 1962 disposed in the lower posterior endplate 1922c and corresponding channels formed in the upper posterior endplate 1922a. Additionally, while shown having one posterior vertical stabilizer 1960, it should be understood that the expandable fusion device 1910 may have any number of vertical stabilizers without departing from the scope of the disclosure.

[0177] By way of example, the second vertical stabilizer 1970 includes a post 1972 associated with the lower forward endplate 1922d, the post extending vertically from a recess 1974 formed in the lower forward endplate 1922d toward the upper forward endplate 1922b. The second vertical stabilizer 1970 further includes a sleeve 1976 associated with the upper forward endplate 1922b, the sleeve having an elongated side 1978 and a channel 1980 configured to slidably receive the post 1980 therein. By way of example only, the post 1972 is inseparably associated with the endplate 1922d (e.g., molded, press-fit, or secured within a corresponding recess, etc.). Similarly, the sleeve 1976 is inseparably associated with the endplate 1922b (e.g., molded, press-fit, or secured within a corresponding recess, etc.). The elongated side 1978 is sized and configured to engage the recess 1974 surrounding the post 1972. The sleeve 1976 functions to extend the length of the channel 1980 so that the post 1972 does not separate from the channel 1980 during vertical deployment. By way of example, the post 1972 and corresponding channel 1980 may have any complementary cross-sectional shape capable of maintaining a passage therethrough, including, but not limited to, circular, oval, elliptical, square, polygonal, irregular, etc. Similarly, the sleeve 1976 and corresponding recess 1974 may have any cross-sectional shape capable of maintaining a passage therethrough, including, but not limited to, circular, oval, elliptical, square, polygonal, irregular, etc. Additionally, while shown with one anterior vertical stabilizer 1970, it should be understood that the expandable fusion device 1910 may have any number of vertical stabilizers without departing from the scope of the disclosure.

[0178] In operation, a first width deployment is performed substantially as described above for the previous embodiment. That is, the actuator 1912 is rotated a selected number of actuations until some width deployment (and in some embodiments, exclusively width deployment) is achieved and the endplate separates from the distal wedge 1914. Once separation occurs, further rotations of the actuator 1912 are performed, increasing at least one of the width, height, and lordosis angle. In other embodiments, the first actuations of the actuator 1912 result in at least some height deployment (and in some embodiments - exclusively height deployment), but further rotations of the actuator 1912 increase at least one of the width, height, and lordosis angle.

[0179] The expandable fusion device 1910 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 1910.

[0180] 114-121 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 2010. By way of example only, the expandable fusion device 2010 of this embodiment includes an actuator 2012, a distal wedge 2014, a proximal wedge 2016, a pair of distal ramps 2018a, 2018b, a pair of proximal ramps 2020a, 2020b, a plurality of endplates 2022a-d, and a plurality (but at least one) of expansion shims 2024. As in the previously described embodiment, the distal and proximal wedges 2014, 2016 are coupled to the actuator 2012. The distal ramps 2018a, 2018b are slidably coupled to the distal wedge 2014. The proximal ramps 2020a, 2020b are slidably coupled to the proximal wedge 2016. The plurality of endplates 2022a-2022d are slidably coupled to the ramps 2018a, 2018b, 2020a, 2020b. By way of example only, the expandable fusion device 2010 illustrates an independent width deployment mechanism that may be applied to any of the expandable fusion device examples described herein, according to some embodiments. Generally, width deployment is achieved by manually inserting a deployment shim 2024 corresponding to the desired width deployment between the proximal ramps 2020a, 2020b, which laterally separates the endplates 2012a-2012d and the distal ramps 2018a, 2018b. Height deployment is achieved by turning the actuator 2012, which advances the wedges 2014, 2016 toward each other. This in turn moves the distal ramps 2018a, 2018b towards the proximal ramps 2020a, 2020b, vertically misaligning the upper and lower endplate pairs. Width expansion and height expansion occur independently of one another, so one is not necessarily a prerequisite for the other. In some embodiments, the width expansion shim 2024 may apply a width expansion force to the endplates rather than the ramps. In some embodiments, the width expansion shim 2024 may apply a width expansion force to the ramps rather than the endplates.In some embodiments, the shims 2024 apply a width expansion force to the upper end plate pair and / or the lower end plate pair, acting as dovetails on such end plate pairs to prevent further width expansion, and each shim is then constrained by at least one end plate to prevent reversal and moves up and down with its respective end plate pair during height expansion and contraction.

[0181] By way of example, actuator 2012 is the same as or substantially similar to actuator 12 described above, and therefore, except where necessary, its specific structure will not be described.

[0182] By way of example, the distal wedge 2014 can be a generally rectangular member having a central threaded bore 2030 configured to threadably receive the threaded distal end of the actuator 2012 therein. The upper and lower surfaces each include a lateral tongue and groove connector 2032 configured to slidably engage a corresponding tongue and groove connector on the distal ramps 2018a, 2018b. By way of example, the tongue and groove connector 2032 can include a lateral ridge 2034 and a lateral groove 2036, each extending at least substantially the proximal width of the distal wedge 2014.

[0183] The proximal wedge 2016 is a generally rectangular member having a central threaded bore 2040 configured to threadably receive the threaded proximal end of the actuator 2012 therein. The upper and lower surfaces each include a lateral tongue and groove connector 2042 configured to slidably engage a corresponding tongue and groove connector of the proximal ramps 2020a, 2020b. By way of example, the tongue and groove connector 2042 includes a lateral ridge 2044 and a lateral groove 2046, each extending at least substantially the width of the distal side of the proximal wedge 2016. The upper and lower surfaces each include a second lateral groove 2048 on a proximal side of the proximal wedge 2016 configured to receive the flange 2109 of the shim 2024 therein.

[0184] By way of example only, the distal ramps 2018a, 2018b each include a pair of distally facing lateral tongue and groove connectors 2050 including a lateral ridge 2052 and a lateral groove 2054 configured to engage with the tongue and groove connector 2032 of the distal wedge 2014 to provide a secure contact between the distal wedge 2014 and the distal ramps 2018a, 2018b. The distal ramps 2018a, 2018b each include a proximally facing angled surface 2056 that interacts with a distal angled surface 2096 of the endplates 2022a-d. A dovetail protrusion 2058 slidably engages a dovetail groove 2098 at the distal end of the endplate to mate the distal end of the endplate to the distal ramps 2018a, 2018b. The distal ramps 2018a, 2018b further include an inner tongue and groove connector 2060 extending parallel to the anterior-posterior axis of the device 2010 and configured to engage the elongated lip 2106 of the deployed shim 2024 to guide the shim 2024 as it is inserted.

[0185] By way of example only, the proximal ramps 2020a, 2020b each include a pair of distally facing lateral tongue and groove connectors 2070 including a lateral ridge 2072 and a lateral groove 2074 configured to engage with the tongue and groove connectors 2042 of the proximal wedge 2016 to provide a secure contact between the proximal wedge 2016 and the proximal ramps 2020a, 2020b. The proximal ramps 2020a, 2020b each include a distally facing angled surface 2076 that interacts with a proximal angled surface 2096 of the endplates 2022a-d. A dovetail protrusion 2078 slidably engages a dovetail groove 2098 at the proximal end of the endplate to mate the proximal end of the endplate to the proximal ramps 2020a, 2020b. The proximal ramps 2020a, 2020b further each include an inner tongue and groove connector 2080 that extends parallel to the anterior-posterior axis of the device 2010 and is configured to engage the elongated lip 2106 of the deployment shim 2024 to guide the shim 2024 as it is inserted. The proximal ramps 2020a, 2020b further each include an inwardly angled guide surface 2082 at an inner proximal corner that engages the tapered distal end 2102 of the deployment shim 2024 to force the ramps 2020a, 2020b apart to effect width deployment as the shim 2024 is inserted.

[0186] By way of example only, each of the end plates 2022a-d has a distal end 2090, a proximal end 2092, and an outer vertebral contacting surface 2094. Each distal end 2090 includes a distally facing angled surface 2096 configured to slidably engage with the angled surface 2056 of the distal ramps 2018a, 2018b to facilitate height deployment. Each distal end 2090 further includes a dovetail groove 2098 configured to slidably engage with the dovetail protrusion 2058 on the distal ramps 2018a, 2018b to align the distal end of the end plate with the distal ramps 2018a, 2018b. Each proximal end 2092 includes a proximally facing angled surface 2096 configured to slidably engage with the angled surface 2076 of the proximal ramps 2020a, 2020b to facilitate height deployment. Each proximal end 2092 further includes a dovetail groove 2098 configured to slidably engage the dovetail protrusion 2078 on the proximal ramps 2020a, 2020b to align the proximal end of the endplate with the proximal ramps 2020a, 2020b.

[0187] By way of example only, the deployment shims 2024 each include a proximal end 2100, a tapered distal end 2102, and parallel sides 2104 (although it is envisioned that in other embodiments the shim may be stepped and include two or more sets of parallel sides to form two or more regions of different shim widths). The parallel sides 2104 each include an elongated lip 2106 that extends toward the actuator 2012 and is configured to engage with an axial tongue and groove connector 2060, 2080 to maintain alignment during insertion. Optionally, the tongue and groove connector engagement may be on an end plate rather than a ramp. The proximal end 2100 includes a deflectable pawl 2108 that includes a vertical flange 2109 at the proximal end of the pawl 2108. When the deployment shim 2024 is fully inserted into the device 2010, the vertical flange 2109 snaps into the second lateral groove 2048 of the proximal wedge 2016, securing the shim 2024 and thus locking the width deployment in place.

[0188] The expandable fusion device 2010 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2010.

[0189] 122-133 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 2 illustrates one example of an expandable fusion device 2110. By way of example only, the expandable fusion device 2110 of this embodiment includes an actuator 2112, a distal wedge 2114, a proximal wedge 2116, a pair of distal ramps 2118a, 2118b, a pair of proximal ramps 2120a, 2120b, and a plurality of endplates 2122a-d. As in the previously described embodiments, the distal and proximal wedges 2114, 2116 are coupled to the actuator 2112. The distal ramps 2118a, 2118b are slidably coupled to the distal wedge 2114. The proximal ramps 2120a, 2120b are slidably coupled to the proximal wedge 2116. The plurality of end plates 2122a-2122d are slidably coupled to the ramps 2118a, 2118b, 2120a, 2120b. In general, the expandable fusion device 2110 is substantially similar to the expandable fusion device 2010 described above, and any / all of the mechanisms described above with respect to the fusion device 2010 (and any other fusion device described herein) may be applied to the fusion device 2110 unless otherwise noted. By way of example only, the expandable fusion device 2110 illustrates an independent width deployment mechanism that may be applied to any example of an expandable fusion device described herein, according to some embodiments. In general, width deployment is accomplished by manually inserting a deployment shim 2124 corresponding to the desired width deployment between the proximal ramps 2120a, 2120b, which laterally separates the end plates 2012a-2112d and the distal ramps 2118a, 2118b. The width deployment is fixed in place by removing the shim 2124 and mating the side walls of the wedges 2114, 2116 with the ramps 2118a, 2118b, 2120a, 2120b. Height deployment is achieved by turning the actuator 2112, which advances the wedges 2114, 2116 towards each other. This in turn moves the distal ramps 2118a, 2118b towards the proximal ramps 2120a, 2120b, vertically misaligning the upper and lower endplate pairs. Width deployment and height deployment occur independently of each other and therefore one is not necessarily a prerequisite for the other.In one embodiment, the shim 2124 has at least one longitudinal fin that is intended to engage at least one (e.g., central) groove / channel on at least the proximal wedge and optionally the distal wedge (best seen in FIG. 129 or 130). The shim's fins slidably fit into the channels on the wedges, preventing the shim from moving laterally across the plane along the long axis of the shim to allow for uneven width expansion. (Left vs. Right - see FIGS. 131-133). In some embodiments, the shim 2124 may apply a width expansion force to the upper pair of endplates and / or the lower pair of endplates. In some embodiments, the width expansion shim 2124 may apply a width expansion force to the endplates and not the ramps. In some embodiments, the width expansion shim 2124 may apply a width expansion force to the ramps and not the endplates.

[0190] By way of example, actuator 2112 is the same as or substantially similar to actuator 12 described above, and therefore its specific structure will not be described unless necessary. Similarly, the specific structures (e.g., ramps, dovetails, etc.) that enable height deployment of distal and proximal ramps 2118a, 2118b, 2120a, 2120b are the same as the corresponding structures of distal and proximal ramps 2018a, 2018b, 2020a, 2020b described above. Additionally, end plates 2122a-2122d are the same in structure and function as end plates 2022a-2022d described above, and therefore will not be described in detail with respect to this embodiment.

[0191] By way of example, the distal wedge 2114 may be a generally rectangular member having a central threaded bore 2130 configured to threadably receive the threaded distal end of the actuator 2112 therein. The upper and lower surfaces each include a lateral tongue and groove connector 2132 configured to slidably engage a corresponding tongue and groove connector on the distal ramps 2118a, 2118b. By way of example, the tongue and groove connector 2132 includes a lateral ridge 2134 and a lateral groove 2136, each extending at least substantially the proximal width of the distal wedge 2114. In particular, the distal wall of the lateral groove 2136 includes a plurality of side walls 2138 configured to engage complementary side walls 2156 provided on the distal ramps 2118a, 2118b, as described below, to selectively lock the width deployment at a desired width.

[0192] By way of example, the proximal wedge 2116 may be a generally rectangular member having a central threaded bore 2140 configured to threadably receive the threaded distal end of the actuator 2112 therein. The upper and lower surfaces each include a lateral tongue and groove connector 2142 configured to slidably engage a corresponding tongue and groove connector on the proximal ramps 2120a, 2120b. By way of example, the tongue and groove connector 2142 includes a lateral ridge 2144 and a lateral groove 2146, each extending at least substantially the proximal width of the proximal wedge 2116. In particular, the proximal wall of the lateral groove 2146 includes a plurality of side walls 2148 configured to engage complementary side walls 2166 provided on the proximal ramps 2120a, 2120b, as described below, to selectively lock the width deployment at a desired width.

[0193] By way of example only, the distal ramps 2118a, 2118b each include a pair of distally facing lateral tongue and groove connectors 2150 including lateral ridges 2152 and lateral grooves 2154 configured to engage with the tongue and groove connectors 2132 of the distal wedge 2114 to provide a secure interface between the distal wedge 2114 and the distal ramps 2118a, 2118b. In particular, the distally facing surfaces of the lateral ridges 2152 include a plurality of side walls 2156 configured to engage complementary side walls 2138 provided on the distal wedge 2114, as described below, to selectively lock the width deployment at a desired width. The distal ramps 2118a, 2118b further each include an inwardly angled guide surface 2158 at an inner distal corner that mates with the tapered distal end of the deployment shim 2124 and forces the ramps 2118a and 2118b apart to achieve width deployment upon insertion of the shim 2124. Because the expandable fusion device 2110 of this embodiment is symmetrical in multiple planes, the terms "proximal" and "distal" are relative terms for purposes of example only, and both the proximal and distal ends may currently be treated as leading and trailing ends.

[0194] By way of example only, the proximal ramps 2120a, 2120b each include a pair of distally facing lateral tongue and groove connectors 2160 including lateral ridges 2162 and lateral grooves 2164 configured to engage with the tongue and groove connectors 2142 of the proximal wedge 2116 to provide a secure interface between the proximal wedge 2116 and the proximal ramps 2120a, 2120b. In particular, the proximal facing surfaces of the lateral ridges 2162 include a plurality of side walls 2166 configured to engage complementary side walls 2148 of the proximal wedge 2116, as described below, to selectively lock the width deployment at a desired width. The proximal ramps 2120a, 2120b further each include an inwardly angled guide surface 2168 at an inner proximal corner that mates with the tapered distal end of the deployment shim 2124 to force the ramps 2120a, 2120b apart upon insertion of the shim 2124 to effect width deployment.

[0195] 129-130, it should be noted that, as shown by way of example in FIG. 129, the lateral groove 2146 of the proximal wedge is wider than the ridge 2162 of the first and second proximal ramps 2120a, 2120b, and the lateral groove 2164 of the first and second proximal ramps 2120a, 2120b is wider than the ridge 2144 of the proximal wedge 2116, in order to maintain the side walls unlocked by allowing translation of the proximal ramps 2120a, 2120b to achieve width expansion. Similarly, to maintain the sidewalls unlocked by allowing translation of the distal ramps 2118a, 2118b to achieve width deployment, the lateral grooves 2136 of the distal wedges are wider than the ridges 2152 of the first and second distal ramps 2118a, 2118b, and the lateral grooves 2154 of the first and second distal ramps 2118a, 2118b are wider than the ridges 2134 of the distal wedges 2114. Initial rotation of the actuator 2112 draws the distal and proximal wedges 2114, 2116 towards the respective distal and proximal ramps 2118a, 2118b, 2120a, 2120b, interlocking the respective sidewalls as shown in FIG. 130, thereby locking the width deployment of the device 2110. Continued rotation of the actuator 2112 deploys the height without changing the width.

[0196] The side walls allow the device 2110 to deploy in width and lock into place in any configuration. This allows customization of a specific width footprint based on the size and configuration of the shim 2124 selected for the procedure. For example, FIGS. 131-133 show several examples of shims 2124 that can be used in this example embodiment. For example, FIG. 131 shows an example of a shim 2124 that, when used, results in a symmetric bilateral deployment. FIG. 132 shows an example of a shim 2124 that, when used, results in a biased deployment. FIG. 133 shows an example of a shim 2124 that, when used, results in a unilateral deployment.

[0197] The expandable fusion device 2110 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2110.

[0198] 134-140 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 2 illustrates an example of an expandable fusion device 2210. By way of example only, the expandable fusion device 2210 of this embodiment includes an actuator 2212, a distal wedge 2214, a proximal wedge 2216, a pair of distal ramps 2218a, 2218b, a pair of proximal ramps 2220a, 2220b, a number of end plates 2222a-d, and a number of guide pins 2223. As in the previously described embodiments, the distal and proximal wedges 2214, 2216 are coupled to the actuator 2212. The distal ramp 2218a is slidably coupled to the distal wedge 2214, and the distal ramp 2218b is integrally formed (or otherwise fixed) with the distal wedge 2214. Proximal ramp 2220a is slidably coupled to proximal wedge 2216, and proximal ramp 2220b is integrally formed (or otherwise fixed) with proximal wedge 2216. Multiple end plates 2222a-d are slidably coupled to ramps 2218a, 2218b, 2220a, 2220b. In general, expandable fusion device 2210 is substantially similar to expandable fusion device 2110 described above, and any / all of the features described above with respect to fusion device 2110 (and any other fusion device described herein) may be applied to fusion device 2210 unless otherwise noted. By way of example only, expandable fusion device 2210 illustrates an independent unidirectional width deployment feature that may be applied to any expandable fusion device example described herein, according to some embodiments. Generally, width deployment is accomplished by manually inserting a deployment shim (not shown) corresponding to the desired width deployment between the proximal wedges 2116 and the proximal ramps 2120a, which laterally separates the endplates 2112a-2112d and the distal structures. The shim is removed and the width deployment is locked in place by mating the side walls of the wedges 2214, 2216 with the ramps 2218a, 2220a. Height deployment is accomplished by turning the actuator 2212, which advances the wedges 2214, 2216 toward each other. This in turn moves the distal ramps 2218a, 2218b toward the proximal ramps 2220a, 2220b, vertically misaligning the upper and lower endplate pairs. Width deployment and height deployment occur independently of each other, and one is not necessarily a prerequisite for the other.

[0199] By way of example only, actuator 2112 is the same as or substantially similar to actuator 12 described above, and therefore its specific structure will not be described, except where necessary. Similarly, the particular structures (e.g., ramps, dovetails, etc.) that enable height deployment of distal and proximal ramps 2218a, 2220a are the same as the corresponding structures of distal and proximal ramps 2018a, 2020a described above. Additionally, end plates 2122a-2122d are the same as (or substantially similar to) end plates 2022a-2022d (and / or other embodiments) described above in structure and function, and therefore will not be described in detail with respect to this embodiment.

[0200] 137-138 illustrate one example of a distal wedge 2214 of this embodiment. By way of example, the distal wedge 2214 may be a generally rectangular member having a central threaded bore 2230 configured to threadably receive the threaded distal end of the actuator 2212 therein. The upper and lower surfaces each include a lateral tongue and groove connector 2232 that slidably engages a corresponding tongue and groove connector on the distal ramp 2118a. By way of example, tongue and groove connector 2232 includes a lateral ridge 2234 and a lateral groove 2236, each extending at least substantially the proximal width of distal wedge 2214. In particular, a distal wall of lateral groove 2236 includes a plurality of side walls 2238 configured to engage complementary side walls 2256 provided on distal ramp 2218a, as described below, to selectively lock the width deployment at a desired width.

[0201] By way of example, the proximal wedge 2216 may be a generally rectangular member having a central threaded bore 2240 configured to threadably receive the threaded distal end of the actuator 2212 therein. The upper and lower surfaces each include a lateral tongue and groove connector 2242 configured to slidably engage a corresponding tongue and groove connector on the proximal ramp 2220a. By way of example, the tongue and groove connector 2242 includes a lateral ridge 2244 and a lateral groove 2246, each extending at least substantially the proximal width of the proximal wedge 2216. In particular, the proximal wall of the lateral groove 2246 includes a plurality of side walls 2248 configured to engage complementary side walls 2266 provided on the proximal ramp 2220a, as described below, to selectively lock the width deployment at a desired width.

[0202] By way of example only, the first distal ramp 2218a includes a pair of elongated intermediate extensions 2251 that function to extend the maximum width deployment distance. The first distal ramp 2218a includes a pair of distally facing lateral tongue and groove connectors 2250 that extend the length of the intermediate extensions 2251 and include a lateral ridge 2252 and a lateral groove 2254 that are configured to engage with the tongue and groove connectors 2232 of the distal wedge 2214 to provide a secure contact between the distal wedge 2214 and the distal ramp 2218a. In particular, the distally facing surfaces of the lateral ridges 2252 include a plurality of side walls 2256 that are configured to engage with complementary side walls 2238 provided on the distal wedge 2214 to selectively fix the width deployment at a desired width. In the initial folded state, when the actuator separates the proximal and distal wedges, the engaged side walls are separated (or "unclasped") to effect width deployment. When the actuator is actuated and the wedges are drawn together, at least one pair of side walls engage and interdigitate to lock / prevent any further width deployment and / or width contraction. The distal ramp 2218a further includes an inwardly angled guide surface 2258 that engages with a tapered distal end of a deployment shim (not shown) to laterally move the ramp 2218a during shim insertion to effect width deployment. As the present embodiment of the deployable fusion device 2210 is symmetrical in multiple planes, the terms "proximal" and "distal" are relative terms for illustrative purposes only, and both the proximal and distal ends may currently be treated as leading and trailing ends.

[0203] 137-138, the second distal ramp 2218b is integrally formed with the distal wedge 2214. By way of example, the second distal ramp 2218b includes a truncated chevron shaped ramp including an angled translation surface 2253 that interacts with the angled surfaces of the endplates 2222b, 2222d (in a manner taught throughout this disclosure) and an optional ramp groove 2255 (to accommodate the guide pin 2223).

[0204] By way of example only, the first proximal ramp 2220a includes a pair of elongated intermediate extensions 2261 that function to extend the maximum width deployment distance. The first proximal ramp 2220a includes a pair of distally facing lateral tongue and groove connectors 2260 that extend the length of the intermediate extensions 2261 and include a lateral ridge 2262 and a lateral groove 2264 that are configured to engage with the tongue and groove connectors 2242 of the proximal wedge 2216 to provide a secure contact point between the proximal wedge 2216 and the proximal ramp 2220a. In particular, the proximal facing surfaces of the lateral ridges 2262 include a plurality of side walls 2266 configured to engage with complementary side walls 2248 provided on the proximal wedge 2216 to selectively secure the width deployment at a desired width. The proximal ramp 2220a further includes an inwardly angled guide surface 2268 that mates with the tapered distal end of the deployment shim 2224 to laterally translate the ramp 2220a during shim insertion to achieve width deployment. Similar to the second distal ramp 2218b described above, the second proximal ramp 2220b is integrally formed with the proximal wedge 2216. By way of example, the second distal ramp 2218b includes a truncated chevron shaped ramp including a sloped translation surface that interacts with the sloped surfaces of the endplates 2222b, 2222d (in a manner taught throughout this disclosure) and an optional ramp groove (to accommodate the guide pin 2223).

[0205] As with the previous embodiment, it should be noted that the lateral groove 2246 of the proximal wedge 2216 is wider than the bump 2262 of the first proximal ramp 2220a and the lateral groove 2264 of the first proximal ramp 2220a is wider than the bump 2244 of the proximal wedge 2216 to maintain the sidewalls unlocked by allowing translation of the proximal ramp 2220a to achieve width expansion, as shown by way of example in FIG. 138. Similarly, the lateral groove 2236 of the distal wedge 2214 is wider than the bump 2252 of the first distal ramp 2218a and the lateral groove 2254 of the first distal ramp 2218a is wider than the bump 2234 of the distal wedge 2214 to maintain the sidewalls unlocked by allowing translation of the distal ramp 2218a to achieve width expansion. Initial rotation of the actuator 2212 draws the distal and proximal wedges 2214, 2216 towards the respective distal and proximal ramps 2218a, 2220a, interlocking their respective side walls as shown in Fig. 139, thereby fixing the deployed width of the device 2210. Continued rotation of the actuator 2212 deploys the height without changing the width.

[0206] The side walls allow the width of the device 2210 to expand and be locked into place in any configuration, allowing a specific width footprint to be customized based on the size and configuration of shims selected for the procedure.

[0207] The expandable fusion device 2210 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2210.

[0208] 141-145 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 1 illustrates an example of an expandable fusion device 2310. The expandable fusion device 2310 differs from embodiments previously disclosed herein in that it is expandable in length as well as width and height, although it is contemplated that other embodiments may further alter / expand the lordosis angle as taught elsewhere herein. As used herein, "length" is defined as the distance from the most proximal point of any endplate to the most distal point of any endplate. By way of example only, the expandable fusion device 2310 of this embodiment includes a first deployment unit 2311a, a second deployment unit 2311b, a first actuator 2312, and a second actuator 2313. The first actuator is operable to deploy the deployment units 2311a, 2311b in width and height. The second actuator 2313 is operable to adjust the length of the expandable fusion device 2310.

[0209] By way of example, the first deployment unit 2311a may be substantially similar to one or more of the example embodiments of the deployable fusion device disclosed herein, such as, for example, the deployable fusion device 10 described above. By way of example only, the first deployment unit 2311a includes a proximal wedge 2314, an inner wedge 2316, a pair of proximal ramps 2318, a pair of inner ramps 2320, and a plurality of end plates 2322. As in the previously described embodiments, the proximal wedge 2318 is slidably coupled to the proximal wedge 2314. The inner ramp 2320 is slidably coupled to the inner wedge 2316. The plurality of end plates 2322 are slidably coupled to the ramps 2318, 2320. In general, the expandable fusion device 2310 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to the fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 2310 unless otherwise stated. In particular, the structure of the width and height expansion of the deployment unit 2311a, as it relates to the structure and interaction between the proximal wedge 2314, the medial wedge 2316 (which is essentially the distal wedge for the width and height expansion of the deployment unit 2311a), the ramps 2318, 2320, and the endplates 2322, is the same as the structure and interaction of the corresponding elements of the expandable fusion device 10 described above, and therefore the details of the width and height expansion components of the deployment unit 2311 will not be described further herein.

[0210] By way of example, the second deployment unit 2311b may be substantially similar to one or more of the example embodiments of the deployable fusion device disclosed herein, such as, for example, the deployable fusion device 10 described above. By way of example only, the second deployment unit 2311b includes a distal wedge 2315, an inner wedge 2317, a pair of distal ramps 2319, a pair of inner ramps 2321, and a plurality of end plates 2323. As in the previously described embodiments, the distal wedge 2318 is slidably coupled to the distal wedge 2315. The inner ramp 2321 is slidably coupled to the inner wedge 2317. The plurality of end plates 2323 are slidably coupled to the ramps 2319, 2321. The structure of the width and height expansion of the expansion unit 2311b, particularly with respect to the structure and interaction between the distal wedge 2315, the medial wedge 2317 (which is essentially the proximal wedge for the width and height expansion of the expansion unit 2311b), the ramps 2319, 2321, and the end plate 2323, is the same as the structure and interaction of the corresponding elements of the expandable fusion device 10 described above, and therefore the details of the width and height expansion components of the expansion unit 2311b will not be described further herein.

[0211] The first actuator 2312 is substantially similar to the actuator 12 described above (but longer in length) and includes a cylindrical elongated shaft having a first threaded mechanism at a distal end and a second threaded mechanism at a proximal end. The threaded mechanisms are separated by an unthreaded portion disposed between the distal and proximal ends. At least one of the distal and proximal ends includes a drive mechanism 2324 configured to mate with a drive instrument (not shown) to actuate the actuator. Each of the first and second threaded mechanisms includes threads disposed circumferentially outside the shaft of the actuator 2312. By way of example, the first and second threaded mechanisms may have opposite thread directions. The proximal end of the first actuator 2312 is configured to mate with a threaded opening of the proximal wedge 2314, and the distal end of the first actuator 2312 is configured to mate with a threaded opening of the distal wedge.

[0212] The second actuator 2313 includes a cylindrical elongated shaft having a first screw mechanism 2326 at a proximal end and a second screw mechanism 2327 at a distal end. The screw mechanisms are separated, for example, at or near the midpoint of the shaft, by a turnbuckle 2328 disposed on the shaft. The turnbuckle 2328 includes a profile or textured area that provides an engagement point for an instrument (e.g., a wrench) to effect rotation of the actuator 2313. The first and second screw mechanisms each include threads disposed around the outside of the shaft of the actuator 2313. By way of example, the first screw mechanism 2326 and the second screw mechanism 2327 may have opposite thread directions.

[0213] The inner wedges 2316, 2317 are identical or mirror image equivalents, and therefore only the inner wedge 2316 will be described herein, although it should be understood that all features described in relation to the inner wedge 2316 also apply to the inner wedge 2317. As previously mentioned, certain elements of the inner wedge 2316 that facilitate the deployment of the width and / or height of the first deployment unit 2311a are the same as or substantially similar to corresponding elements of the proximal wedge 16 (for example) of the deployable fusion device 10 described above, and will not be described in further detail. By way of example only, the inner wedge 2316 includes an unthreaded central opening 2330 configured to allow unobstructed passage of the first actuator 2312. The inner wedge 2316 further includes at least one screw passage 2332 disposed laterally of the central opening 2330 and configured to accommodate the proximal portion of the second actuator 2313 (having the first screw mechanism 2326). The associated feature of the inner wedge 2317 is configured to accommodate a distal portion (having a second screw feature 2327) of the second actuator 2313. The inner wedge 2316 further includes an inner cut-out portion 2334, which serves to reserve space for a wrench or other suitable actuation device (not shown) for engaging the turnbuckle 2328 of the second actuator 2313.

[0214] FIG. 141 illustrates the expandable fusion device 2310 of this embodiment in an initial, fully collapsed configuration. FIG. 143 illustrates the expandable fusion device 2310 in a length deployed state. Achieving this state requires a two step process. The first step adjusts the distance between the inner wedges 2316, 2317. Once this distance is set, the second step then adjusts the distance between the proximal and distal wedges 2314, 2315. To adjust the distance between the inner wedges 2316, 2317, a wrench or other suitable device is engaged with the turnbuckle 2328 and the second actuator 2313 is rotated. This causes the threaded interaction between the second actuator 2313 and the inner wedges 2316, 2317 to translate the inner wedges 2316, 2317 away from each other, creating a distance between the inner wedges 2316, 2317 that ultimately indicates the amount of length deployment of the expandable fusion device 2310 as shown in FIG. However, because the proximal and distal wedges 2314, 2315 do not move during this process (or move less than the medial wedges 2416, 2417), the translation of the medial wedges 2316, 2317 initially results in width deployment rather than length deployment of the first and second expandable units 2311 a, 2311 b. Thus, after setting the distance between the medial wedges 2316, 2317, the first actuator 2312 is rotated (for example) counterclockwise to translate the proximal and distal wedges 2314, 2315 away from each other, thereby restoring the width to its original state and achieving the fully extended length as shown in FIG. 143 (e.g., the expandable fusion device 2310 is now deployed in length but collapsed in width and height). This procedure is important to ensure that the end plates 2322, 2323 are in the proper position within the intervertebral space. At this point, the first actuator 2312 may be rotated (eg, clockwise) to effect width deployment (eg, FIG. 144) and height deployment (eg, FIG. 145) in the manner described above.

[0215] The expandable fusion device 2310 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2310.

[0216] 146-151 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 2 illustrates an example of an expandable fusion device 2410. The expandable fusion device 2410 is similar to the device 2310 described above in that the expandable fusion device 2410 is expandable in length as well as width and height. As used herein, "length" is defined as the distance from the most proximal point of any endplate to the most distal point of any endplate. By way of example only, the expandable fusion device 2410 of this embodiment includes a first deployment unit 2411a, a second deployment unit 2411b, a first actuator 2412, and a second actuator 2413. The first actuator is operable to deploy the deployment units 2411a, 2411b in width and height. The second actuator 2413 is operable to adjust the length of the expandable fusion device 2410.

[0217] By way of example, the first deployment unit 2411a may be substantially similar to one or more of the example embodiments of the deployable fusion device disclosed herein, such as, for example, the deployable fusion device 10 described above. By way of example only, the first deployment unit 2411a includes a proximal wedge 2414, an inner wedge 2416, a pair of proximal ramps 2418, a pair of inner ramps 2420, and a plurality of end plates 2422. As in the previously described embodiments, the proximal ramp 2418 is slidably coupled to the proximal wedge 2414. The inner ramp 2420 is slidably coupled to the inner wedge 2416. The plurality of end plates 2422 are slidably coupled to the ramps 2418, 2420. In this embodiment, the location of the ramps 2418, 2420 has been moved to the lateral ends of the endplate 2422 such that the second actuator 2413 is accessible from either the proximal or distal end of the device 2410 (see, e.g., FIGS. 149-151). In general, the expandable fusion device 2410 is substantially similar to the expandable fusion device 10 described above, and any / all of the features described above with respect to fusion device 10 (and any other fusion device described herein) may be applied to the fusion device 2410 unless otherwise noted. In particular, the structure of the width and height expansion of the expansion unit 2411a, relating to the structure and interaction between the proximal wedge 2414, the medial wedge 2416 (which is essentially the distal wedge for the width and height expansion of the expansion unit 2411a), the ramps 2418, 2420, and the end plate 2422, is the same as the structure and interaction of the corresponding elements of the expandable fusion device 10 described above, and therefore the details of the width and height expansion components of the expansion unit 2411a will not be described further herein.

[0218] By way of example, the second deployment unit 2411b may be substantially similar to one or more of the example embodiments of the deployable fusion device disclosed herein, such as the deployable fusion device 10 described above. By way of example only, the second deployment unit 2411b includes a distal wedge 2415, an inner wedge 2417, a pair of distal ramps 2419, a pair of inner ramps 2421, and a plurality of end plates 2423. As in the previously described embodiments, the distal ramp 2418 is slidably coupled to the distal wedge 2415. The inner ramp 2421 is slidably coupled to the inner wedge 2417. The plurality of end plates 2423 are slidably coupled to the ramps 2419, 2421. In this embodiment, the positions of the ramps 2419, 2421 have been moved to the lateral ends of the end plates 2423 such that the second actuator 2413 is accessible from the proximal or distal end of the device 2410. In particular, the structure of the width and height expansion of the expansion unit 2411b, relating to the structure and interaction between the distal wedge 2415, the medial wedge 2417 (which is essentially the proximal wedge for the width and height expansion of the expansion unit 2411b), the ramps 2419, 2421, and the end plate 2423, is the same as the structure and interaction of the corresponding elements of the expandable fusion device 10 described above, and therefore the details of the width and height expansion components of the expansion unit 2411b will not be described further here.

[0219] The first actuator 2412 is substantially similar to the actuator 12 described above (but longer in length) and includes a cylindrical elongated shaft having a first threaded mechanism at a distal end and a second threaded mechanism at a proximal end. The threaded mechanisms are separated by an unthreaded portion disposed between the distal end and the proximal end. At least one of the distal and proximal ends includes a drive mechanism 2424 configured to mate with a drive instrument (not shown) to actuate the actuator. Each of the first and second threaded mechanisms includes a thread disposed circumferentially outside the shaft of the actuator 2412. By way of example, the first and second threaded mechanisms may have opposite thread directions. The proximal end of the first actuator 2412 is configured to mate with a threaded opening of the proximal wedge 2414, and the distal end of the first actuator 2412 is configured to mate with a threaded opening of the distal wedge.

[0220] The second actuator 2413 includes a cylindrical elongated shaft having a first screw mechanism 2426 at a proximal end and a second screw mechanism 2427 at a distal end. The screw mechanisms are separated by an unthreaded portion 2428 disposed on the shaft, for example, at or near the midpoint of the shaft. At least one of the distal and proximal ends includes a drive mechanism 2425 configured to mate with a drive device (not shown) to actuate the second actuator 2413. Each of the first and second screw mechanisms includes threads disposed circumferentially outside the shaft of the actuator 2413. By way of example, the first screw mechanism 2426 and the second screw mechanism 2427 may have opposite thread senses.

[0221] The inner wedges 2416, 2417 are identical or mirror image equivalents, and therefore only the inner wedge 2416 will be described herein, although it should be understood that all features described in relation to the inner wedge 2416 also apply to the inner wedge 2417. As previously mentioned, certain elements of the inner wedge 2416 that facilitate the deployment of the width and / or height of the first deployment unit 2411a are the same as or substantially similar to corresponding elements of the proximal wedge 16 (for example) of the deployable fusion device 10 described above, and will not be described in further detail. By way of example only, the inner wedge 2416 includes an unthreaded central opening 2430 configured to allow unobstructed passage of the first actuator 2412. The inner wedge 2416 further includes at least one screw passage 2432 disposed laterally of the central opening 2430 and configured to accommodate the proximal portion of the second actuator 2413 (having the first screw mechanism 2426). The associated mechanism of the medial wedge 2417 is configured to receive a distal portion (having a second screw mechanism 2427) of the second actuator 2413. As shown in FIGS. 149-151, the second actuator 2413 is accessible from the proximal and / or distal ends of the expandable fusion device 2410. As a result, the length, width, and height of the expandable fusion device 2410 may be adjusted intra-operatively while in the disc space.

[0222] FIG. 146 shows the expandable fusion device 2410 of this embodiment in an initial, fully collapsed configuration. FIG. 148 shows the expandable fusion device 2410 in a length-deployed state. Reaching this state requires a two-step process. The first step adjusts the distance between the inner wedges 2416, 2417. Once this distance is set, the second step then adjusts the distance between the proximal and distal wedges 2414, 2415. To adjust the distance between the inner wedges 2416, 2417, a drive instrument is inserted into the proximal wedge 2414 (or distal wedge 2415) and engages the drive mechanism 2428 of the second actuator 2413, causing the second actuator 2413 to rotate. This causes the threaded interaction between the second actuator 2413 and the medial wedges 2416, 2417 to translate the medial wedges 2416, 2417 away from one another, creating a distance between the medial wedges 2416, 2417 that ultimately indicates the amount of length deployment of the expandable fusion device 2410 as shown in FIGURE 147. However, because the proximal and distal wedges 2414, 2415 do not move during this process (or move less than the medial wedges 2416, 2417), the translation of the medial wedges 2416, 2417 initially results in width deployment rather than length deployment of the first and second expandable units 2411a, 2411b. Thus, after setting the distance between the medial wedges 2416, 2417, the first actuator 2412 is rotated (for example) counterclockwise to translate the proximal and distal wedges 2414, 2415 away from one another, thereby returning the width to its original state and achieving a fully extended length as shown in FIGS. 148 and 149 (e.g., the expandable fusion device 2410 is now expanded in length but collapsed in width and height). This procedure is important to ensure that the end plates 2422, 2423 are in the proper position within the intervertebral space. At this point, the first actuator 2412 may be rotated (e.g., clockwise) to effect width deployment (e.g., FIG. 150) and height deployment (e.g., FIG. 151) in the manner described above.

[0223] The expandable fusion device 2410 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2410.

[0224] 152-153 are diagrams illustrating a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 2 illustrates an example of an expandable fusion device 2510. By way of example only, the expandable fusion device 2510 of this embodiment includes an actuator 2512, a distal wedge 2514, a proximal wedge 2516, a pair of identical distal ramps 2518, a pair of identical proximal ramps 1820, a plurality of end plates 1822a-d, and a plurality of optional guide pins. As in the previously described embodiments, the distal and proximal wedges 2514, 2516 are coupled to the actuator 2512. The distal ramp 2518 is slidably coupled to the distal wedge 2514. The proximal ramp 2520 is slidably coupled to the proximal wedge 2516. The plurality of end plates 2522a-d are slidably coupled to the ramps 2518, 2520. In general, the expandable fusion device 2510 is substantially similar to the expandable fusion device 1810 described above, and any / all of the features described above with respect to fusion device 1810 (and any other fusion device described herein) may be applied to fusion device 2510 unless otherwise noted. By way of example only, the expandable fusion device 2510 illustrates an expandable fusion device that expands in width and height and in a lordotic deployment that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0225] By way of example, the actuator 2512, distal wedge 2514, and proximal wedge 2516 can be the same as or substantially similar to corresponding elements disclosed with respect to other embodiments herein.

[0226] 153 illustrates an example of a proximal ramp 2520 according to an example embodiment. By way of example only, the proximal ramp 2520 of the example embodiment is substantially similar to the proximal ramp 1820 of the device 1810, but is lordotic. Instead of one or more arcuate ramps (e.g., arcuate ramps 1864, 1866 described above) to support deployment, the proximal ramps 2520 of this embodiment have a laterally facing cylindrical boss 2530 configured to be received within a boss opening 2532 at the proximal end of each endplate 2522a-d such that the endplates 2522a-d are pivotally engaged with the proximal ramp 2520. In the single boss embodiment, the endplates 2522a-d may be configured with nested projections 2234 in which the boss openings 2532 are formed. The ends of the bosses may be crimped or otherwise restrained within the boss openings 2532.

[0227] In operation, a first width deployment is proceeded substantially as described above for the previous embodiment. That is, the actuator 2512 is rotated a selected number of actuations until some width deployment (and in some embodiments, exclusively width deployment) is reached and the endplate separates from the distal wedge 2514. Once disengagement occurs, further rotation of the actuator 2512 causes the distal ramps 2518 to translate along the respective angled grooves of the endplates and the endplates to pivot about the cylindrical bosses 2530, increasing at least one of the width, height, and lordosis angle in the process. That is, actuation of the drive mechanism a first number of actuations in a first actuation direction results in a width deployment. Actuation of the drive mechanism a second number of actuations beyond the first number of actuations in the first actuation direction then increases at least one of the width, lordosis angle, and in some embodiments, height. In other embodiments, a first actuation of the actuator 2512 results in at least some height expansion (and in some embodiments - exclusively height expansion), but further rotation of the actuator 1912 increases at least one of the width, height, and lordosis angle.

[0228] The expandable fusion device 2510 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2510.

[0229] 154-155 show a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 2 illustrates an example of an expandable fusion device 2610. By way of example only, the expandable fusion device 2610 of this embodiment includes an actuator 2612, a distal wedge 2614, a proximal wedge 2616, a pair of identical distal ramps 2618, a pair of identical proximal ramps 1820, a plurality of end plates 1822a-d, and a plurality of optional guide pins. As in the previously described embodiments, the distal and proximal wedges 2614, 2616 are coupled to the actuator 2612. The distal ramp 2618 is slidably coupled to the distal wedge 2614. The proximal ramp 2620 is slidably coupled to the proximal wedge 2616. The plurality of end plates 2622a-d are slidably coupled to the ramps 2618, 2620. In general, the expandable fusion device 2610 is substantially similar to the expandable fusion device 1810 (FIGS. 100-105) described above, and any / all of the features described above with respect to fusion device 1810 (and any other fusion device described herein) may be applied to fusion device 2610 unless otherwise noted. By way of example only, the expandable fusion device 2610 illustrates an expandable fusion device that expands in width and height and lordotic deployment that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0230] By way of example, the actuator 2612, the distal wedge 2614, and the proximal wedge 2616 can be the same as or substantially similar to corresponding elements disclosed with respect to other embodiments herein.

[0231] FIG. 155 shows an example of this embodiment. 2 shows an example of a proximal ramp 2620. By way of example only, the proximal ramp 2620 of this embodiment is substantially similar to the proximal ramp 1820 of the device 1810, but instead of one or more arcuate ramps (e.g., arcuate ramps 1864, 1866 described above) that effect lordotic deployment, the proximal ramp 2620 of this embodiment has a laterally facing cylindrical boss 2630 configured to be received within a boss opening 2632 at the proximal end of each endplate 2622a-d such that the endplates 2622a-d are pivotally engaged with the proximal ramp 2620. The end of the boss may be crimped or otherwise restrained within the boss opening 2632.

[0232] In operation, a first width deployment is proceeded substantially as described above for the previous embodiment. That is, the actuator 2612 is rotated a selected number of actuations until maximum width deployment is reached and the endplates disengage from the distal wedges 2614. Once disengagement occurs, further rotation of the actuator 2612 causes the distal ramps 2618 to translate along the respective angled grooves of the endplates, causing each endplate to pivot about a different cylindrical boss 2630, increasing at least one of the width, height, and lordosis angle in the process. That is, actuation of the drive mechanism a first number of actuations in a first actuation direction deploys the width. Actuation of the drive mechanism a second number of actuations beyond the first number of actuations in the first actuation direction then increases at least one of the width, height, and lordosis angle. In other embodiments, a first actuation of the actuator 2512 results in at least some height expansion (and in some embodiments - exclusively height expansion), but further rotation of the actuator 1912 increases at least one of the width, height, and lordosis angle.

[0233] The expandable fusion device 2610 of this example embodiment may additionally or alternatively include any of the features, components, or characteristics of any of the various example embodiments of the expandable fusion device described herein. Furthermore, any additionally described expandable fusion device may further include any of the features, components, or characteristics of the expandable fusion device 2610.

[0234] FIG. 156 is a cross-sectional view of a catheter for implantation between two adjacent vertebrae according to another embodiment of the present disclosure. 27 illustrates an example of an expandable fusion device 2710. By way of example only, the expandable fusion device 2710 illustrates an expandable fusion device that expands in width and height and in a lateral lordotic deployment that may be applied to any of the expandable fusion device examples described herein, according to some embodiments.

[0235] In this embodiment, the ramps are curved in a plane transverse to the long axis of the device, causing the endplates to then lordotically deploy in a plane transverse to the long axis. Optionally, the endplates can be maintained in alignment with nested stabilizer slides having substantially the same curvature as the ramps in the same transverse plane.

[0236] The teachings contained herein include illustrations that are merely exemplary in nature and are not intended to limit the teachings, their application or use in any way. While the teachings are generally directed to embodiments of a deployable fusion device and methods for its implantation between two adjacent lumbar vertebrae into the spine using lateral, posterior and transforaminal approaches, it should be understood that similar mechanisms and arrangements thereof are also used to treat cervical, thoracic and spinal segments utilizing other surgical approaches, including but not limited to pedicle, transiliac, anterior and anterior-lateral approaches, configured to engage the respective anatomical structures and approach angles. Similarly, while the present teachings are generally directed to embodiments of a deployable fusion device, it should be understood that this may include a drive system having an actuator that draws wedges together to cause deployment, for example, possibly in combination with a spacer system that is independent of the drive system, and in other embodiments, the actuator may accomplish the same function by forcing the wedges apart, or perhaps the spacer or spacers may be any suitable object of any shape, size or configuration that can separate structural components in a manner similar or substantially similar to the teachings described herein.

[0237] Unless otherwise defined, all technical terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. References to "or" herein are intended to include "and / or" unless otherwise stated. The term "about" may be used to express a variance of a stated quantity, including an amount or range of 0.1%, close to 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% of the stated quantity. The term "longitudinal axis" may be used to refer to a theoretical axis in space that includes the axis of rotational symmetry of an object. The term "slidably coupled" may be used to refer to a relationship between two or more components in which the components share at least one degree of freedom. The term "external width" may be used to refer to the width between the outermost surfaces of an object. The term "external distance" may be used to refer to the distance between the outermost surfaces of an object. The term "apex" may be used to refer to the maximum value of a distance, measurement, or parameter. The term "thread feature" may be used to refer to one or more helical or spiral projections or recesses that act as or can interface with another thread feature.

[0238] It should further be understood that the devices taught herein are deployable, i.e., foldable in some embodiments. One advantage is that each embodiment has a folded configuration and can be inserted into a target space through a small surgical passage, such as an intervertebral space. They have an deployed configuration for deployment in a target space, serving as a scaffold to support surrounding tissue, which may be, for example, tissue surrounding the intervertebral space, as well as bone graft material in spinal fusion. In some embodiments, the devices are designed to deploy only in a cephalocaudal direction, with "cephalocaudal" deployment also referred to as "craniocaudal" deployment, and possibly also referred to as "vertical" deployment. In some embodiments, the devices are designed to deploy only in a transverse direction, with transverse deployment also referred to as "lateral" deployment. That is, one skilled in the art will understand that this design is designed to include and work with only one deployment system described herein. That is, the present teachings are expressly intended to represent unilaterally deployable devices that are only cranio-caudal and only laterally deployable, and one of skill in the art may use any one of the deployment systems taught herein to deploy the end plates of the device either only laterally or only longitudinally. However, the embodiment most particularly shown and described is a device that includes both of the deployment systems taught herein, a coordinated design that includes a drive system and a spacer system, each system designed to operate independently of the other in a single device, providing improvements and addressing problems in the art, at least as described herein.

[0239] Additionally, the methods, devices, and systems taught herein can be used with any subject, for example, for experimental purposes or for medical treatment. The terms "subject" and "patient" can be used interchangeably in some aspects and can be used to refer to animals, such as mammals, including but not limited to non-primates, such as cows, pigs, horses, cats, dogs, and primates, such as monkeys and humans. Thus, the terms "subject" and "patient" can be applied to non-human biological applications, including but not limited to farm animals, pets, commercial livestock, and the like.

[0240] Additionally, the term "degree" is used herein to provide a relative relationship between the positions and / or movements of components of the systems taught herein. For example, the phrase "at least substantially" can be used to refer to an approximation relating to a quantity or position, or a function of a quantity or position, or a function relating to the other. For example, an axis that is at least substantially parallel to another axis can be used to refer to a direction that is intended to be parallel for all practical purposes, but this is merely a convenient reference, and it is understood that there may be variations due to stresses within the system and imperfections in devices and systems. Similarly, the phrases "at least substantially parallel," "at least substantially on a plane," or "at least substantially coincident" can each refer to a type of direction or movement that is intended to be, for all practical purposes, on or near an axis, plane, etc., or, in some cases, a point as a convenient measure of direction or movement, without suffering from difficult definitions or final evaluations, unless a definition is known to those skilled in the art as a convenient reference, and allow for differences until there are variations due to stresses within the system and imperfections in devices and systems that affect the operation of the methods, devices, and systems to the point that they cannot be used any more, and in some embodiments, to the point that they do not function. In some embodiments, the terms "at least substantially parallel," "at least substantially in plane," or "at least substantially coincident" can be described, for example, as any dimensional tolerance from "0°" (which in some embodiments means "parallel" or "in plane"), such as an angular dimensional tolerance in an amount of about 1°, about 2°, about 3°, about 4°, about 5° from parallel or in plane, or any range or amount in 0.1 increments therein, and such as an angular dimensional tolerance in an amount of about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, or any range or amount in 0.1 mm increments therein.

Claims

1. 1. An expandable fusion device, comprising: a wedge assembly coupled to an actuator having a drive mechanism for width deployment, the wedge assembly having a distal wedge and a proximal wedge, each of the distal wedge and the proximal wedge having an isosceles trapezoidal prism shape; a ramp assembly slidably coupled to the wedge assembly for height deployment, the ramp assembly having a first distal ramp and a first proximal ramp, the distal wedge slidably engaged with the distal ramp by a tongue and groove connector, and the proximal wedge engaged with the proximal ramp by a tongue and groove connector; and 1. An interfitting end plate system comprising: The interlocking end plate system a separable upper end plate assembly slidably engaged with the lamp assembly, the separable upper end plate assembly having a first end plate and a second end plate, the upper end plate having a plurality of first protrusions extending inwardly from the first end plate and received in corresponding grooves formed in an outer contact surface of the second upper end plate, and the second end plate having a plurality of second protrusions extending inwardly from the second end plate and received by corresponding grooves formed in an outer contact surface of the first upper end plate; and a separable lower end plate assembly slidably engaged with the lamp assembly, the separable lower end plate assembly having a third end plate and a fourth end plate, the third end plate having a plurality of third protrusions extending inwardly from the third end plate and received in corresponding grooves formed in an outer contact surface of the second lower end plate, and the fourth end plate having a plurality of second protrusions extending inwardly from the fourth end plate and received by corresponding grooves formed in an outer contact surface of the first lower end plate; the interfitting end plate system including: Including, Here, the first plurality of projections interfit with the second plurality of projections to provide a flush, slidable engagement between the first projections and the second projections in widthwise deployment; the third plurality of projections interfit with the fourth plurality of projections to provide a flush, slidable engagement between the third projections and the fourth projections in widthwise deployment; and the interdigitated endplate system, wherein the device provides surfaces for contact with upper and lower vertebral endplates; and wherein: a first number of actuations of the drive mechanism in a first actuation direction results in an increase in width without an increase in height; and a second number of actuations of the drive mechanism beyond the first number of actuations in the first actuation direction increases the height; The expandable fusion device.

2. each of the first plurality of protrusions has a mating surface on the second end plate, wherein the mating surface is a recess; and each of the third plurality of protrusions has an engagement surface on the fourth end plate, wherein the engagement surface is a recess; The expansion fusion device of claim 1.

3. each of the first plurality of protrusions has an engagement surface on the second end plate, wherein the engagement surface is a groove; and each of the third plurality of protrusions has an engagement surface on the fourth end plate, wherein the engagement surface is a groove; The expansion fusion device of claim 1.

4. each of the first plurality of protrusions has an engagement surface on the second end plate, wherein the engagement surface is a channel; and each of the third plurality of protrusions has an engagement surface on the fourth end plate, wherein the engagement surface is a channel; The expansion fusion device of claim 1.

5. each of the first plurality of protrusions has an engagement surface on the second end plate, wherein the engagement surface is a port; and each of the third plurality of protrusions has an engagement surface on the fourth end plate, wherein the engagement surface is a port; The expansion fusion device of claim 1.

6. the first plurality of projections extend inwardly from the first end plate and nest in grooves in the second end plate; and the third plurality of projections extend inwardly from the third end plate and nest in grooves in the fourth end plate; The expansion fusion device of claim 1.

7. the first plurality of projections and the second plurality of projections slidably translate in a tongue and groove configuration to provide additional rigidity to the upper end plate assembly during width deployment; and the third plurality of projections and the fourth plurality of projections slidably translate in a tongue and groove configuration to provide additional rigidity to the lower end plate assembly during width expansion. The expansion fusion device of claim 1.

8. The expansion fusion device of claim 1 , wherein each of the first endplate, the second endplate, the third endplate, and the fourth endplate is a rigid beam having an anterior-posterior axis.

9. the actuator draws the proximal and distal wedges together or apart; and The wedge assembly provides force to extend the device via an actuator, and the ramp assembly redirects the force from the wedge assembly to the end plate. The expansion fusion device of claim 1.

10. 10. The expandable fusion device of claim 9, wherein the ramp assembly includes a first distal ramp, a second distal ramp, a first proximal ramp, and a second proximal ramp.

11. The expansion fusion device of claim 1 , wherein at least one of the second endplate and the fourth endplate is larger than at least one of the first endplate and the third endplate.

12. The expandable fusion device of claim 9 , wherein the actuator comprises a screw mechanism.

13. The expansion fusion device of claim 1 , wherein the device further comprises a deployment lock.

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