Expandable lordotic interbody implants and related methods

Abstract

The present disclosure relates to an expandable interbody implant, the expandable interbody implant comprising upper and lower shells surrounding a control mechanism having interlocking proximal and distal cages and an adjustment screw that translates the distal cage longitudinally relative to the proximal cage, thereby pushing apart the distal ends of the upper and lower shells to deploy the interbody implant.

Description

Technical Field

[0001] The present disclosure relates to deployable implants such as intervertebral spinal devices and interbody devices, and more particularly to intervertebral spinal implants that are deployable after placement in the spine.

Background Art

[0002] Fixed cages, and other types of intervertebral implants and devices, are often used in spinal surgery within the vertebrae or in the intervertebral disc space (intervertebral) between each vertebra. When using an interbody device, one or more such vertebral bodies are placed between the vertebrae to promote support and fixation of adjacent vertebrae. Such fixation may be necessary due to disease, injury, general deterioration, or congenital problems.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The goal of most spinal surgeries is to minimize the trauma of the surgery itself. One way to minimize trauma is to provide the smallest possible access port to reach the surgical site, but a small access port limits the size of the tools and implants that can pass through the access port.

[0004] However, some interbody devices are currently formed to be deployable. The deployable intervertebral implant is initially smaller than a conventional non-deployable (static) intervertebral implant so that the deployable intervertebral implant can be inserted and / or implanted more easily into the intervertebral disc space. The deployable intervertebral implant is deployed to a desired size to achieve the amount of deployment required for a particular patient when placed in the intervertebral disc space.

Means for Solving the Problems

[0005] This disclosure relates to a deployable lordotic interbody implant that is inserted into the intervertebral disc space in a folded state to minimize patient trauma and can then be deployed to achieve a desired lordosis. The interbody implant comprises an upper shell and a lower shell surrounding a control mechanism. The upper and lower shells may each have at least one graft window, which in some embodiments are aligned with one another. The control mechanism comprises an interlocking proximal and distal cage and an adjustment screw that longitudinally translates the distal cage relative to the proximal cage. The translation of the distal cage pushes open the distal ends of the upper and lower shells, respectively, and deploys the interbody implant.

[0006] In one embodiment, one or both of the upper and lower shells have angled slots in their side walls that extend distally toward a central plane dividing the intervertebral implant into upper and lower halves. The proximal and distal cages contained within and interlocked within the upper and lower shells are configured to be longitudinally parallel to each other by adjustment screws that screw into and engage with the proximal or distal cage.

[0007] In one embodiment, the adjustment screw engages with a screw hole located distal to the distal cage, while the proximal end of the adjustment screw is fixed to the proximal cage so as to be fixed longitudinally to the proximal cage. This may be done using a pin inserted into the distal end of the proximal cage, which is configured to engage with a radial groove or flange of the adjustment screw.

[0008] In some embodiments, the adjustment screw engages with a screw hole located distal to the distal cage, while the distal end of the adjustment screw contacts the inner surface of the distal end of the distal cage, and in some embodiments, is configured to apply pressure. At least a portion of the distal end of the adjustment screw may be tapered or rounded to reduce friction between the adjustment screw and the distal cage. In some embodiments, one or more rods are fitted into or fixed to the distal cage (as described in more detail below) to longitudinally fix the adjustment screw to the distal cage. In such embodiments, the distal end of the adjustment screw has a radial groove or flange for engaging with the rod. In some embodiments, one or more ends of the rod may function as a lateral projection that slides along an angled slot. In some embodiments, the rod may be integrated with the distal cage.

[0009] Whether screwed into or engaged with the proximal or distal cage, rotation of the adjustment screw causes the distal cage to move longitudinally, pressing its distal end against the inner surfaces of the upper and lower shells. Alternatively, the lateral projection of the distal cage slides along slots in the side walls of the upper and lower shells, pushing them apart. As the proximal ends of both the upper and lower shells rotate and engage with the proximal end of the proximal cage, the unfolding force applied to the upper and lower shells by the distal cage causes them to open into a clamshell shape, achieving lordosis when inserted between the two vertebrae of the spine.

[0010] In some embodiments, the distal end of the distal cage has an inclined surface, a tapered surface, a rounded surface, and / or an inclined surface. In some embodiments, a rod, which may have a coefficient of friction lower than that of the material of the distal cage, is inserted or fixed at the distal position of the distal cage so as to be a contact point between the inner surfaces of the upper and lower shells and the distal cage. In some embodiments, the rod is the primary or sole contact point.

[0011] In one embodiment, a deployable intervertebral implant has one or more retaining projections configured to deploy or expand from the intervertebral implant when deployed. The retaining projections are sharp and may be embedded in the upper and lower vertebrae, or at least resist the movement of the intervertebral implant. In one embodiment, the proximal end of the retaining projection is fixed to or forms part of a rod that is fitted into or rotatably fixed to a distal cage. Translation of the distal cage pushes the retaining projection out of the respective holes or windows of the upper and lower shells, which may be located distally.

[0012] In one embodiment, the edges of the upper and lower shells are configured to contact each other to completely or at least partially enclose the control assembly when the intervertebral implant is folded. In one embodiment, the edge of one shell has a projection, and the edge of the other shell has a corresponding recess configured to receive the projection, thereby providing further rigidity to the folded intervertebral implant. In one embodiment, the upper and lower shells are at least partially nested inside each other when folded. In one embodiment, the side walls of the proximal and distal cages are configured to contact the inner surfaces of the upper and lower shells, providing stability or rigidity not only in the folded state but also in the unfolded state.

[0013] In one embodiment, the deployable intervertebral implant comprises one or more metals, such as steel, cobalt, cobalt-chromium, titanium, or alloys thereof. In another embodiment, the intervertebral implant further comprises one or more polymers, such as polyether-ether-ketone (PEEK). In yet another embodiment, at least a portion of the intervertebral implant comprises a porous material, such as a porous metal (e.g., one or more layers of porous titanium).

[0014] This specification further discloses embodiments of an insert for use with a deployable intervertebral implant. The insert may comprise: (1) a handle portion including an extension portion, the extension portion having a cannula extending from the proximal end of the handle portion to the distal end of the extension portion; (2) an engagement mechanism for engaging with a deployable intervertebral implant, and the engagement mechanism having one or more reverse torque extension portions for preventing rotation of the intervertebral implant, the engagement portion being provided at the distal end of the extension portion; and (3) a deployment tool extending from the proximal end of the cannula to the distal end of the cannula to be inserted into the deployable intervertebral implant and engage with an adjustment screw to actuate the adjustment screw.

[0015] Some embodiments of the implant are provided with a deployment indicator, which may be located on the handle or extension. The deployment indicator visually indicates to the user the degree to which the intervertebral implant is deployed in its position. In some embodiments, the intervertebral implant can be “pre-deployed,” meaning that in the folded state, the upper and lower shells are at least partially deployed to achieve greater deployment when deployed. In such embodiments, different deployment tools corresponding to different degrees of pre-deployment may be used to work with the deployment indicator to accurately indicate the degree of deployment.

[0016] This specification further discloses a method for implanting and deploying a deployable intervertebral implant. In such a method, (1) an insert is used to position the intervertebral implant, which may be folded or pre-deployed, into the intervertebral disc cavity; (2) the intervertebral implant is deployed by rotating a control knob on the insert to deploy the intervertebral implant; and (3) the deployed intervertebral implant is released or removed from the insert. In some embodiments, the method further comprises the step of injecting or inserting bone growth material into the intervertebral implant, which may be performed by the insert or by using a separate device. In embodiments in which an insert is used, a portion of the insert is removed in order to allow the insert to inject or insert bone growth material into the intervertebral implant. [Brief explanation of the drawing]

[0017] The embodiments described in the drawings are in practice illustrative and typical and are not intended to limit the subject matter defined by the claims. The following detailed description of the exemplary embodiments can be better understood when read together with the following drawings, in which similar structures are indicated by similar reference numerals.

[0018] [Figure 1] This is a perspective front view showing an embodiment of a deployable intervertebral implant in a folded or unfolded state. [Figure 2] This is a perspective rear view showing the embodiment of Figure 1 in an unfolded state. [Figure 3] This is a side view showing the embodiment of Figure 1 in its unfolded state. [Figure 4] This is an exploded rear view showing the embodiment of Figure 1. [Figure 5A] This is a top view showing the deployable intervertebral implant in Figure 1 in its undeployed state. [Figure 5B] Figure 5A is a side cross-sectional view showing the deployable intervertebral implant of Figure 1 in an undeployed state along line DD. [Figure 6A]It is a top view showing the expandable intervertebral implant of FIG. 1 in an expanded state. [Figure 6B] It is a side sectional view showing the expandable intervertebral implant of FIG. 1 in an expanded state along line D-D shown in FIG. 6A. [Figure 7] It is a perspective view showing an insert engaged with the expandable intervertebral implant of FIG. 1. [Figure 8] It is a perspective view showing the distal portion of the insert of FIG. 7 removed from the expandable intervertebral implant of FIG. 1. [Figure 9] It is a perspective front view showing another embodiment of the expandable intervertebral implant in a folded state or an unexpanded state. [Figure 10] It is a perspective front view showing the embodiment of FIG.A9 in an expanded state. [Figure 11] It is an exploded front view showing the embodiment of FIG. 9. [Figure 12] [[ID=2,1]]It is an exploded front view showing another embodiment of the expandable intervertebral implant. [Figure 13] It is an exploded front view showing another embodiment of the expandable intervertebral implant.

MODE FOR CARRYING OUT THE INVENTION

[0019] The present disclosure relates to an expandable and / or dynamic (between adjacent vertebrae) intervertebral implant, an intervertebral body (within a vertebra), and / or a spinal stabilization device that can be used as an intervertebral fixation cage or device, a device for stabilizing one or more intervertebral spaces, etc. (hereinafter collectively referred to as (one or more) spinal devices) for promoting support, stabilization and / or bone growth between or within vertebrae that have become unstable or damaged due to injury or disease. In particular, the present disclosure provides various versions of dynamic (expandable and / or expandable and retractable) intervertebral devices that can be used in the human spine and can achieve or promote an appropriate anterior curvature.

[0020] Figure 1 shows a typical dynamic intervertebral device or deployable implant or intervertebral implant 10. Figure 1 is a perspective front view of the intervertebral implant 10 in an undeployed or folded state. The intervertebral implant 10 comprises an upper shell 15 and a lower shell 20. The upper surface of the upper shell 15 is configured to contact and support the lower surface of a first vertebra. Similarly, the lower surface of the lower shell 20 is configured to contact and support the upper surface of a second vertebra. In this illustrated embodiment, the upper shell 15 and the lower shell 20 have projections or dentate bodies 22 configured to resist or minimize the movement of the intervertebral implant 10 after it has been placed in the intervertebral space between the first and second vertebrae. In some embodiments, a rough surface, which can be achieved by coating and / or surface treatment, is further or alternatively provided. The first and second vertebrae can represent, for example, L1-L2, L2-L3, L3-L4, L4-L5, or L5-S1 in the human spine. However, the intervertebral implant 10 may be used in the thoracic or cervical vertebrae instead.

[0021] Both the upper shell 15 and the lower shell 20 are configured to move hinge-like at their respective proximal ends at the upper hinge point 25 and the lower hinge point 30. The distal ends of the upper shell 15 and the lower shell 20 are illustrated to be tapered or have a bullet-like shape. The tapered portion of the distal end may be helpful when inserting the intervertebral implant 10 into the intervertebral disc space, although in some embodiments the distal end of the intervertebral implant 10 is not tapered at all. In some embodiments such a tapered portion may consist of a relatively straight but angled surface, and in some embodiments such a tapered portion may include one or more curves.

[0022] Figure 1 shows that the edges of the upper shell 15 and the lower shell 20 are in contact with each other when not unfolded to form a closed shell. It can be seen that both the upper shell 15 and the lower shell 20 have a horizontal plane and their respective side walls. Figure 1 shows that one side wall of the upper shell 15 has an angled slot 35. In this illustrated embodiment, a similar slot is provided on the opposite side wall of the lower shell 20 on the intervertebral implant 10 side, which is not shown in Figure 1. These angled slots extend through the upper shell 15 and the lower shell 20, although in some embodiments the slots do not extend completely through the shell and instead have channels or recesses formed on the inner surface of the shell.

[0023] Although not shown, in one embodiment, the edges of the side walls may have projections and corresponding holes or slots for receiving these projections. For example, the lower surface of the side wall of the upper shell 15 may have one or more projections that, when unfolded, are received by corresponding holes on the upper surface of the side wall of the lower shell 20. Such a configuration can enhance the structural integrity or stability of the intervertebral implant 10 when unfolded and may be particularly useful when the intervertebral implant 10 is inserted into the intervertebral space and subjected to compressive forces to be precisely positioned.

[0024] Figure 1 further shows that the upper shell 15 has a graft window 40. A similar graft window is provided in the lower shell 20. These graft windows enable bone growth by the intervertebral implant 10 after it has been implanted. These graft windows further allow materials that induce or promote bone growth to be inserted into or pushed into the intervertebral implant 10 and at least partially flow out of the intervertebral implant 10, and possibly come into contact with and interact with the bone surfaces of the upper and lower vertebral bodies. In some embodiments, the intervertebral implant 10 has only one graft window or no graft windows at all. In some embodiments, the intervertebral implant 10 has three or more graft windows, and these graft windows may be located in positions other than those shown in Figure 1. In some embodiments, as will be described in more detail below, the intervertebral implant 10 can achieve new internal bone growth instead of or in addition to through-growth.

[0025] Figure 2 is a perspective posterior view of the intervertebral implant 10. This perspective posterior view shows that the intervertebral implant 10 includes a proximal cage 50, which is described in more detail below. Figures 1 and 2 show that the upper hinge point 25 and the lower hinge point 30 have a combination of transverse projections of the proximal cage 50 that engage with the respective proximal hooks of the upper shell 15 and the lower shell 20. This configuration allows the upper shell 15 and the lower shell 20 to rotate at their respective proximal ends. In one embodiment, such movement can be achieved by using a pin extending through the proximal cage 50 as the point of rotation. However, using the transverse projections and hooks shown in the drawings not only reduces the number of parts but also allows for a larger female screw hole 110 than when one or more pins are used for the upper hinge point 25 and / or the lower hinge point 30.

[0026] Figure 2 shows that the proximal cage 50 has a threaded hole 110 at its proximal end, configured to receive an insert as shown in Figure 8. In one embodiment, the insert engages the intervertebral implant 10 with any number of other suitable engaging means. The engaging means is, for example, an insert tube that is inserted into a similar key-shaped hole that allows the insert tube to pass through the proximal cage, and then has one or more protruding protrusions that partially rotate to fix the inner wall.

[0027] Figure 3 shows the intervertebral implant 10 in its deployed state. In the deployed state, the distal ends of the upper shell 15 and the lower shell 20 are separated, while their respective proximal ends rotate around the upper hinge point 25 and the lower hinge point 30. In this deployed state and in the perspective view of Figure 3, it can be seen that the intervertebral implant 10 comprises a distal cage 45, a proximal cage 50, and an adjustment screw 55. These elements are sometimes referred to herein as a control assembly. The proximal cage 50 and the distal cage 45 are configured to interlock with each other, as shown in detail in Figure 4, in order to enable relative or parallel movement of the proximal cage 50 and the distal cage 45 along the longitudinal axis, which is the longitudinal axis of the adjustment screw 55, which extends through the opening of the proximal cage 50 and engages by screwing into a screw hole provided at the distal end of the distal cage 45.

[0028] In the illustrated embodiment, when the adjustment screw 55 is rotated to move the distal cage 45 relative to the proximal cage 50, the intervertebral implant 10 is deployed from an undeployed state to an deployed state. Furthermore, since the upper hinge point 25 and the lower hinge point 30 are located at the proximal end of the proximal cage 50, the longitudinal movement of the distal cage 45 applies force to one or more inner surfaces of the upper shell 15 and the lower shell 20, causing the distal ends of the upper shell 15 and the lower shell 20 to open in a clamshell shape.

[0029] In one embodiment, the distal end of the proximal cage 50 has a screw hole that engages with an adjustment screw 55. In such an embodiment, the distal cage 45 does not have a screw hole, but is configured to receive the force applied by the distal end of the adjustment screw 55 as the adjustment screw 55 moves through the proximal cage 50. The force applied to the distal cage 45 by the adjustment screw 55 causes the distal cage 45 to move longitudinally parallel to the proximal cage 50, thereby separating the distal ends of the upper shell 15 and the lower shell 20. By screwing the adjustment screw 55 to the distal end of the proximal cage 50, in one embodiment it is possible to reduce the amount of friction between the adjustment screw 55 and the intervertebral implant 10 so that the force required to rotate the adjustment screw 55 is smaller. Furthermore, by tapering the distal end of the adjustment screw 55, in one embodiment it is possible to further reduce the friction between the adjustment screw 55 and the intervertebral implant 10.

[0030] In the embodiment shown in Figure 3, the distal cage 45 is provided with a tapered distal end. In some embodiments, the tapered distal end has a uniformly angled surface 60. In some embodiments, a rounded surface or cylindrical surface is provided near the distal end of the distal cage 45, either together with or instead of the angled surface 60. In the embodiment shown in Figure 3, the cylindrical surface is provided with a pin or rod 65 positioned in a notch on the upper surface of the distal cage 45. A corresponding pin or rod may be positioned in a notch on the lower surface of the distal cage 45, although in some embodiments only one rod is used. In some embodiments, one or more rods are integrated into the distal cage 45. In some embodiments, the rounded surface or cylindrical surface is provided with a material having a coefficient of friction lower than the coefficient of friction of the material forming the angled surface 60 or the rest of the distal cage 45.

[0031] Figures 1-4 show that the distal cage 45 has a lateral projection 70 configured to slide into an angled slot 35. Comparing the deployed state in Figure 3 with the undeployed states in Figures 1 and 2, it can be seen that the lateral projection 70 moves from the proximal end to the distal end of the angled slot 35. The distal cage 45 has a second lateral projection on the opposite side of the distal cage 45, which is the side not shown in Figure 2. The second lateral projection, similar to the lateral projection 70, is configured to slide into an angled slot provided in the side wall of the lower shell 20. The exact angles of the angled slot 35 in the upper shell 15 (and the corresponding angled slot 85 in the lower shell 20) can be selected to achieve a desired flexion angle and / or desired deployment rate with each rotation of the adjustment screw 55. In one embodiment, the angle of the angled slot 35 is different from the angle of the angled slot 85 of the lower shell 20 so that the intervertebral implant 10 is unfolded unevenly on each side by rotating the adjustment screw 55.

[0032] According to one embodiment, one or both of the rods 65 and / or 80 function as the corresponding lateral projections on the opposite side of the lateral projection 70 and / or distal cage 45. For example, the rods 65 and / or 80 only need to extend beyond the illustrated rods so that they can extend to the side walls of the upper shell 15 and / or lower shell 20. Such a configuration can reduce the number of parts, which can affect not only the cost of the intervertebral implant 10 but also its manufacturability and structural integrity.

[0033] In some embodiments, one or both of the upper shell 15 and the lower shell 20 contain a porous material, which can be a metal, a polymer, or a combination of the two. In some embodiments, one or both of the upper shell 15 and the lower shell 20 have one or more notches or recesses on their outer surfaces, and a layer of porous material is housed, configured to occupy one or more of the notches or recesses on the outer surfaces. In some embodiments, the layer of porous material is simply attached to or fixed to the upper and / or lower surfaces of the intervertebral implant 10, without the use or need of notches. In some embodiments, the porous material is one or more layers of porous sheets, for example, one or more layers of porous titanium sheets. One or more layers of porous titanium can be diffusion bonded to one or more outer surfaces of the upper shell 15 and / or the lower shell 20. In some embodiments, the porous material surrounds one or both of the graft windows, is adjacent to one or both of the graft windows, or replaces one or both of the graft windows. In one embodiment, the porous material is arranged on one or more side walls in addition to or instead of the upper or lower surface of the intervertebral implant 10.

[0034] Figure 4 is an exploded view of an embodiment of Figure 1, further visualizing various components of the intervertebral implant 10. For example, the slot 85 in the side wall of the lower shell 20, and the interdependence of the structures of the proximal cage 50 and distal cage 45 are visible. Figure 4 further shows the inclined surface 75 of the lower shell 20. In this illustrated embodiment, both the lower shell 20 and the upper shell 15 have inclined surfaces that incline toward the distal end of the shell, respectively. As described above, the deployable intervertebral implant 10 deploys when the adjustment screw 55 moves the distal cage 45 longitudinally away from or toward the proximal cage 50. This movement of the distal cage 45 presses the distal portion of the distal cage 45 against at least one of the upper shell 15 and the lower shell 20. In one embodiment, the tapered end or angled surface 60 of the distal cage 45 (and optionally the corresponding angled surface on the underside of the distal cage 45) slides against one or both of the inclined surfaces of the upper shell 15 and the lower shell 20. In another embodiment, the same movement is achieved by rods 65 and / or rod 80 sliding against one or both of the inclined surfaces of the upper shell 15 and the lower shell 20. In yet another embodiment, longitudinal movement of the distal cage 45 causes the lateral projection 70 to slide along the slot 35 (and optionally the corresponding lateral projection on the opposite side of the distal cage 45 to slide along the slot 85 provided on one side wall of the lower shell 20), thereby causing the distal ends of the upper shell 15 and the lower shell 20 to move away from each other.

[0035] In one embodiment, the mechanism by which the deployable intervertebral implant 10 deploys is a combination of all three structural relationships (the tapered end of the distal cage 45, the rods 65 and 80, and the transverse projection 70), a combination of two of these structural relationships, or one of these structural relationships.

[0036] Figure 3 shows that, in this embodiment, the adjustment screw 55 has a threaded portion 90, a head 95, and a flange 100 positioned between the head 95 and the threaded portion 90. When assembled, the adjustment screw 55 extends through an opening in the distal portion of the proximal cage 50, and the threaded portion 90 engages with a threaded hole in the distal cage 45. The longitudinal position of the adjustment screw 55 is fixed to the proximal cage by a pin 105. In this illustrated embodiment, the pin 105 fits into a slot in the distal portion of the proximal cage 50. The pin 105 has a projection or extension that engages with the flange 100 of the adjustment screw 55 to maintain the adjustment screw 55 in a longitudinally fixed orientation relative to the proximal cage 50. In some embodiments, the flange 100 is a groove or recess configured to receive the pin 105. In some embodiments, the flange 100 is associated with the groove or recess. In one embodiment, the pin 105 has a cylindrical shape and engages with the adjustment screw 55 along only one side of the adjustment screw 55.

[0037] The components shown in Figure 4 may be formed from any suitable material, such as one or more metals or one or more polymers. Such materials include titanium, steel, cobalt, gold, platinum, silver, iridium, tantalum, tungsten, alloys thereof, polyvinylidene fluoride, polyethylene, polypropylene, polydimethylsiloxane, parylene, polyamide, polytetrafluoroethylene, polymethyl methacrylate, polyimide, PEEK, and polyurethane. In some embodiments, one or more of the components shown in Figure 4 include a porous material. Porous materials may include porous metals, porous polymers, or mixtures of the two. For example, in some embodiments, one or more components include porous titanium or are manufactured from porous titanium. In some embodiments, the porous titanium includes layered sheets of porous titanium that are diffusion-bonded to each other to form a single object. In some embodiments, one or more of the upper shell 15, lower shell 20, distal cage 45, and proximal cage 50 are manufactured from or include layered sheets of porous titanium that are diffusion-bonded to each other. By using such porous components, bone growth becomes possible not only through the transplant window, but also through or into the intervertebral implant 10 itself.

[0038] An insert (see Figure 7) suitable for use with a deployable intervertebral implant 10 has an engagement means (see Figure 8) that engages with the proximal portion of the proximal cage 50, and the insert has an adjustment tool portion that extends through a screw hole 110 to engage with the head 95 of the adjustment screw 55 so as to deploy or fold the intervertebral implant 10 by rotating the adjustment screw 55.

[0039] Figures 5B and 6B are cross-sectional views of the deployable interbody implant 10 in both its undeployed (Figure 5B) and deployed (Figure 6B) states. These figures illustrate the function of the adjustment screw 55 and how the distal cage 45 interacts with the upper shell 15 and lower shell 20 to force the distal ends of the two shells apart, thereby moving the interbody implant 10 from its undeployed to deployed state.

[0040] Figures 5 and 6 further illustrate how the graft window 40 of the upper shell 15 has a corresponding graft window to the lower shell 20, and further show that the two graft windows, along with the openings in the respective structures of the distal cage 45 and proximal cage 50 (see Figure 4), form an opening throughout the entire depth of the intervertebral implant 10 to allow for bone penetration growth.

[0041] Figure 5 shows that when the intervertebral implant 10 is not deployed, the upper shell 15 and lower shell 20 of the intervertebral implant 10 define substantially parallel and separate surfaces. When not deployed, the upper and lower surfaces of the upper shell 15 and lower shell 20, respectively, may be substantially parallel, or they may have a slight angle, such as about 0.5°, about 1°, about 1.5°, about 2°, in the range of about 0° to about 1°, in the range of about 0.2° to about 1.2°, or in the range of about 0.5° to about 2°. In some embodiments, the angle between the upper and lower surfaces, respectively, may be less than about 5°, less than about 4°, less than about 3°, or less than about 2°. According to some embodiments, if the initial angle or pre-deployment angle between the upper and lower surfaces, respectively, is greater than 0°, it may be possible to achieve a larger angle when deployed.

[0042] In one embodiment, the initial angle is achieved by the configuration of the upper shell 15 and lower shell 20, either with or without the pre-deployed intervertebral implant 10. In one embodiment, the upper shell 15 and / or lower shell 20 are thickened toward their respective distal ends. By configuring the upper shell 15 and / or lower shell 20 in this manner, it is possible to achieve an initial angle of about 1° to about 15°, including any angle between the upper shell 15 and the lower shell 20. In one embodiment, the resulting initial angle is at least about 1°, at least about 3°, at least about 5°, at least about 7°, at least about 9°, at least about 11°, at least about 13°, less than about 14°, less than about 12°, less than about 10°, less than about 8°, less than about 6°, and / or less than about 4°.

[0043] In one embodiment, the internal components of the intervertebral implant 10 are identical in embodiments with and without the initial angle. In other words, in one embodiment without the initial angle, an expansion angle of about 20° can be achieved, while the same internal components used in embodiments with a thicker shell having an initial angle of about 10° can achieve an expansion angle of about 30°.

[0044] The length of the interbody implant 10, defined as the distance between the most proximal and most distal portions of the upper shell 15 (or lower shell 20), can be any suitable value. In some embodiments, the length is in the range of approximately 14 mm to approximately 41 mm, including any value between approximately 14 mm and approximately 41 mm. In some embodiments, the length of the interbody implant 10 is approximately 20 mm, approximately 22.5 mm, approximately 25 mm, approximately 27.5 mm, approximately 30 mm, approximately 32.5 mm, at least approximately 20 mm, at least approximately 25 mm, at least approximately 30 mm, at least approximately 35 mm, less than approximately 40 mm, less than approximately 37 mm, less than approximately 33 mm, less than approximately 27 mm, in the range of approximately 15 mm to approximately 25 mm, in the range of approximately 20 mm to approximately 30 mm, or in the range of approximately 25 mm to approximately 35 mm.

[0045] The width of the intervertebral implant 10, which is determined as the distance between the outer edges of the respective side walls of the upper shell 15 (or lower shell 20), can be any suitable value. In some embodiments, the width value is selected to provide maximum stability to the upper and lower vertebrae. In some embodiments, the width is in the range of approximately 7 mm to approximately 27 mm, including any value between approximately 7 mm and approximately 27 mm. In one embodiment, this value is approximately 8 mm, approximately 10 mm, approximately 12 mm, approximately 14 mm, approximately 16 mm, approximately 18 mm, approximately 20 mm, approximately 22 mm, approximately 24 mm, approximately 26 mm, at least approximately 7.5 mm, at least approximately 12.5 mm, at least approximately 17.5 mm, at least approximately 22.5 mm, less than approximately 27 mm, less than approximately 23 mm, less than approximately 19 mm, less than approximately 15 mm, in the range of approximately 7 mm to approximately 13 mm, in the range of approximately 9 mm to approximately 15 mm, in the range of approximately 11 mm to approximately 17 mm, in the range of approximately 13 mm to approximately 19 mm, in the range of approximately 15 mm to approximately 21 mm, in the range of approximately 17 mm to approximately 23 mm, or in the range of approximately 19 mm to approximately 25 mm.

[0046] Figure 6 shows that the angle between the respective faces defined by the upper shell 15 and lower shell 20 in the unfolded state can be in the range of approximately 4° to approximately 40°, including any value between approximately 4° and approximately 40°. In one embodiment, the angle is approximately 10°, approximately 15°, approximately 20°, approximately 25°, approximately 30°, or approximately 35°. In one embodiment, the angle in the unfolded state is at least about 5°, at least about 10°, at least about 15°, at least about 20°, at least about 25°, at least about 30°, in the range of about 5° to about 10°, in the range of about 7.5° to about 12.5°, in the range of about 10° to about 15°, in the range of about 12.5° to about 17.5°, in the range of about 15° to about 20°, in the range of about 17.5° to about 22.5°, in the range of about 20° to about 25°, in the range of about 22.5° to about 27.5°, in the range of about 25° to about 30°, or in the range of about 27.5° to about 32.5°.

[0047] Figure 7 shows an insert 115 for use with an intervertebral implant 10. The insert 115 has a distal end configured to engage with the proximal end of the intervertebral implant 10 and a proximal end configured to be handled and manipulated by a user (e.g., a surgeon). The insert 115 has a deployment tool 120 including a handle 125 and a rod (not shown). The rod extends through a lumen that extends for the length of the insert 115 and extends at least partially beyond the distal end of the insert 115 so that it extends at least partially into the intervertebral implant 10 when the insert 115 engages with the intervertebral implant 10. The distal end of the rod of the deployment tool 120 is configured to engage with the head 95 of an adjustment screw 55. Thus, rotation of the handle 125 rotates the rod of the deployment tool 120, and then the adjustment screw 55 rotates to deploy or fold the intervertebral implant 10.

[0048] The distal end of the insert 115 has a threaded engagement portion 150 (see Figure 8) and a transverse extension portion 130. The engagement portion 150 is configured to engage with the threaded hole 110 of the proximal cage 50. The transverse extension portion 130 provides a counter-torque to the rotation applied by the engagement portion 150 to hold the intervertebral implant 10 in place while the engagement portion 150 rotates to engage or disengage the insert 115 from the intervertebral implant 10. The engagement portion 150 is operated by rotating an engagement knob 135 located toward the proximal end of the insert 115.

[0049] Figure 8 shows that the engagement portion 150 is hollow. This allows the deployment tool 120 to pass through the engagement portion 150 and extend into the intervertebral implant 10, passing through the proximal portion of the proximal cage 50 and engaging with the adjustment screw. Although not shown, the deployment tool 120 can be removed from the insert 115 in order to inject a biologic or bone growth-promoting material into the intervertebral implant 10 via the insert 115.

[0050] Furthermore, in one embodiment, particularly when the intervertebral implant 10 is not deployed, the lateral extension portion 130 contacts the proximal edges of the side walls of the upper shell 15 and the lower shell 20, respectively. This configuration allows the insertor 115 to distribute the insertion force or compressive force to the shell portion, rather than the proximal cage 50 bearing the entire insertion force.

[0051] The proximal portion of the insert 115 has a surface that facilitates the use of the insert 115 for insertion, withdrawal, deployment, or folding of the intervertebral implant 10. In the embodiment shown in Figure 7, the proximal portion of the insert 115 has a plane that is easy for the surgeon to grasp. The proximal portion may further have a deployment indicator 140 that indicates the amount or degree of deployment of the intervertebral implant 10. The deployment indicator 140 may be particularly useful for the surgeon because the deployment may not be visible when the intervertebral implant 10 is inserted into the intervertebral space. Furthermore, fluoroscopic images are unlikely to provide the surgeon with accurate information regarding the deployment angle obtained at that position. The deployment indicator 140 may give a percentage value of the deployment. For example, if the intervertebral implant 10 is configured to achieve an angle of 20° when fully deployed, the deployment indicator 140 will show the percentage of that angle achieved. If the intervertebral implant 10 is not deployed (before insertion), the deployment indicator 140 will show a deployment percentage of 0%. When the intervertebral implant 10 is deployed to approximately 10°, the deployment indicator 140 shows a 50% deployment rate, and when the intervertebral implant 10 is deployed to approximately 20°, the deployment indicator 140 shows a 100% deployment rate. In one embodiment, the deployment indicator 140 is configured to provide the actual degree or angle of deployment.

[0052] In one embodiment, the un-deployed state of the intervertebral implant 10 is defined as a configuration in which the angle between the upper and lower surfaces is greater than 0°. Such a configuration may be advantageous in that it allows for a greater degree of deployment or deployment angle in the final deployed state. In one embodiment, the initial angle is in the range of about 0.5° to about 10°, including any angle between about 0.5° and about 10°. In one embodiment, the initial angle is in the range of about 1°, about 1.5°, about 2°, about 2.5°, about 3°, about 3.5°, about 4°, about 4.5°, about 1° greater, about 3° greater, less than about 9°, less than 7°, in the range of about 0.5° to about 3.5°, in the range of about 2.5° to about 5.5°, in the range of about 4.5° to about 7.5°, and in the range of about 6.5° to about 9.5°.

[0053] As described above, the rotation of the deployment tool 120 not only deploys the intervertebral implant 10, but in some embodiments, it also acts on the deployment indicator 140 to indicate to the surgeon the degree or percentage of deployment achieved by the intervertebral implant 10 at that position. In some embodiments, when the intervertebral implant 10 is initially pre-deployed (e.g., a minimum angle greater than 0°), the deployment tool 120 communicates with the deployment indicator 140 to indicate such pre-deployment. For example, different deployment tools 120 may be provided for each degree or percentage of pre-deployment. In other words, if the intervertebral implant 10 has 1° pre-deployment and 5° pre-deployment, one specific deployment tool 120 is used each time the insert 115 is connected to the intervertebral implant with 1° pre-deployment, so that this is communicated by the deployment tool 120 to the deployment indicator 140. When the intervertebral implant is used with 5° pre-deployment, a different deployment tool 120 is used. For example, if an intervertebral implant 10 is initially pre-deployed to 5° and can reach a 25° exposure, the deployment tool 120 is configured such that the deployment indicator 140 shows the initial exposure as 20%. Therefore, when the surgeon inserts the intervertebral implant 10, the deployment indicator 140 alerts the surgeon that the intervertebral implant 10 is pre-deployed or has an initial exposure greater than 0°. However, in some embodiments, such pre-deployment is not indicated by the deployment indicator 140.

[0054] The insert 115 shown in Figure 7 has a notch facing its proximal end. This notch (and any corresponding notches on the underside of the insert 115) is configured to engage with a reverse torque device (not shown). Such a device may be used to hold the insert 115 in place and prevent twisting of the insert 115 when the handle 125 of the deployment tool 120 is rotated to deploy the intervertebral implant 10.

[0055] The intervertebral implant 10 may be surgically implanted in the patient using any number of suitable methods. In one embodiment, the method for implanting the intervertebral implant 10 includes the first step of engaging the distal end of the insert 115 with the proximal end of the proximal cage 50. This step is performed by bringing the distal tip of the insert 115 into contact with the proximal end of the proximal cage 50 and rotating the engagement knob 135, and then rotating the engagement portion 150 to engage the threads of the engagement portion 150 with the threads of the threaded holes 110 of the proximal cage 50. The engagement knob 135 is rotated until the lateral extension portion 130 advances completely into the respective slots of the proximal end of the intervertebral implant 10 formed in the proximal end of the proximal cage 50 and the proximal ends of the respective side walls of the upper shell 15 and lower shell 20. When the insert 115 engages with the intervertebral implant 10, the deployment tool 120 is inserted through the insert 115, allowing the distal end of the deployment tool to engage with the adjustment screw 55. In one embodiment, the deployment tool 120 is already in a predetermined position within the insert 115 before the insert 115 engages with the intervertebral implant 10.

[0056] Subsequently, the intervertebral implant 10 is positioned within the intervertebral disc space as desired. The positioning of the intervertebral implant 10 to the desired location may be performed using fluoroscopy. For this purpose, one or more components of the intervertebral implant 10 may be at least partially radiopaque. In some embodiments, the intervertebral implant 10 is equipped with one or more radiopaque markers, the primary purpose of which is to assist in the proper positioning of the intervertebral implant 10 within the intervertebral disc space. In some embodiments, the deployment tool 120 is not inserted through the insert 115 until the intervertebral implant 10 is properly positioned within the intervertebral disc space. In embodiments where the intervertebral implant 10 is positioned before the deployment tool 120 is inserted, the proximal end of the insert 115 may be configured to withstand hammer blows that may be required to properly position the intervertebral implant 10.

[0057] With the intervertebral implant 10 properly positioned, a deployment tool 120, which may need to be inserted through the insert 115 at this stage, rotates to rotate the adjustment screw 55, thereby moving the distal cage 45 longitudinally relative to the proximal cage 50. Moving the distal cage 45 away from the proximal cage 50 applies outward pressure to the upper shell 15 and the lower shell 20. In some embodiments, this outward pressure arises from lateral projections 70 (and corresponding lateral projections on the opposite side of the distal cage 45) that slide along angled slots 35 and 85, respectively. In some embodiments, this outward pressure arises from the tapered distal end of the distal cage 45 pressing against the inclined surfaces inside the upper shell 15 and the lower shell 20. In some embodiments, this outward pressure arises from rods 65, 80 pressing against the inclined surfaces inside the upper shell 15 and the lower shell 20. In one embodiment, this outward pressure arises from a combination of two or more of these structural interactions.

[0058] The intervertebral implant 10 is deployed by continuing to rotate the deployment tool 120 until the desired deployment amount is reached. The deployment amount can be observed using a deployment indicator 140 that indicates the deployment amount in terms of degree of deployment, deployment rate, or any other suitable method.

[0059] Once the desired deployment amount is reached, the deployment tool 120 is removed from the insert 115. In one embodiment, the biologic or bone growth-promoting material is then injected into the intervertebral implant 10 by injecting it through the cannula structure of the insert 115. In another embodiment, such material is injected into the intervertebral implant 10 or the space surrounding the intervertebral implant 10 after the insert has been removed from the intervertebral implant 10. The insert is removed from the intervertebral implant by turning the engagement knob 135 until the distal tip of the insert 115 can be freely withdrawn from the surgical space without affecting the position of the intervertebral implant 10.

[0060] Figure 9 shows an alternative embodiment of a deployable intervertebral implant 210 comprising an upper shell 215 and a lower shell 220. Many embodiments of the intervertebral implant 210 are similar to embodiments of the intervertebral implant 10 (including an upper hinge point 225, a lower hinge point 230, a proximal cage 250, a transverse projection 270, an angled slot 235, a dentate body 222, and a graft window 240), but the upper shell 215 and lower shell 220 have openings on their upper and lower surfaces toward the distal end of the intervertebral implant 210, respectively. In the perspective view shown in Figure 9, only the upper opening 212 is shown, but in this embodiment, an opening corresponding to the lower shell 220 is provided. In some embodiments, only one shell has such an opening.

[0061] Figure 10 shows that when the intervertebral implant 210 is deployed (by angled inclinations 260 pressing against the inner surfaces of the upper shell 215 and the lower shell 220, and / or by lateral projections 270 sliding along angled slots 235 and lateral projections (not shown) sliding along angled slots 285, and / or by rods 265, 280 sliding along the inner inclined surfaces of the upper shell 215 and the lower shell 220), the distal ends of the upper shell 215 and the lower shell 220 separate in a clamshell-like manner and engage with the upper and lower vertebral bodies, as well as by retaining projections extending through openings formed in the upper shell 215 and the lower shell 220 to prevent, limit, or reduce the movement or displacement of the intervertebral implant 210 within the intervertebral space. Similar to the intervertebral implant 10, the intervertebral implant 210 comprises an upper rod 265 and a lower rod 280, but in this embodiment, the upper rod 265 functions as a connection point and hinge point for an upper retaining projection 214 that extends through the upper opening 212 when the intervertebral implant 210 is deployed. Correspondingly, the lower rod 280 functions as a connection point and hinge point for a lower retaining projection 216 that extends through the lower opening. In some embodiments, only one expandable retaining projection is provided. In some embodiments, the retaining projection is integrated with the rod. In some embodiments, the retaining projection rotates freely about the rod. The longitudinal translation of the distal cage 245 distally forces the upper retaining projection 214 and the lower retaining projection 216 into their respective openings and slides along their respective openings so that they deploy or extend from the intervertebral implant 210. Conversely, the parallel movement of the distal cage 245 towards the proximal side pulls the superior retaining process 214 and the inferior retaining process 216 back into the intervertebral implant 210.

[0062] Figure 11 is an exploded view of an intervertebral implant 210 which may show how the upper retaining projection 214 and the lower retaining projection 216 are connected to the upper rod 265 and the lower rod 280, respectively. In some embodiments, the two components may be melted, joined, bonded or glued together, or they may consist of a single part.

[0063] Figure 11 further shows that the distal end of the proximal cage 250 has a threaded hole 224. In this embodiment, the distal cage 245 does not have a threaded hole. This means that the adjustment screw 255 is screwed into the threaded hole 224, and when it rotates, moving the adjustment screw 255 longitudinally distally presses the distal end of the adjustment screw 255 against the distal end of the distal cage 245 (the distal end of the adjustment screw 255 may be tapered to reduce friction on part or all of the distal surface of the tip, but is shown as smooth or rounded), thereby moving the distal cage 245, which pushes open the distal ends of the upper shell 215 and the lower shell 220. In one embodiment, the distal end of the adjustment screw 255 is held in place in a predetermined position within the distal end of the distal cage 245 by a pin that allows the adjustment screw 255 to rotate freely. In one embodiment, the distal end of the adjustment screw 255 is configured to snap into place with the distal cage 245.

[0064] In one embodiment, a resistance element (not shown) may be incorporated into the proximal cage 250, preferably at the distal end of the proximal cage 250. Such a resistance element may have a threaded interior through which an adjustment screw 255 is screwed. However, unlike the threaded holes 224 of the proximal cage 250, the resistance element is configured to apply at least some resistance to the rotation of the adjustment screw 255. Such resistance can prevent the intervertebral implant 210, which is deployable during and / or postoperatively, from being accidentally folded and losing volume. The resistance element may include any number of suitable materials, e.g., metals (e.g., steel, titanium, alloys thereof) or polymers (polyvinylidene fluoride, polyethylene, polypropylene, polydimethylsiloxane, parylene, polyamide, polytetrafluoroethylene, polymethyl methacrylate, silicone, polyimide, PEEK, polyurethane, or combinations thereof). In one embodiment, the resistive element is screwed inside, while in another embodiment, the resistive element is not screwed inside and simply applies frictional force to the adjustment screw 255.

[0065] Figure 12 shows an alternative embodiment of the deployable interbody implant 310 that differs significantly from the deployable interbody implant 210 in terms of the configuration of the adjustment screw 355 and how the adjustment screw 355 interacts with the proximal cage 350 and distal cage 345. The other embodiment of the deployable interbody implant 310 mainly reflects the embodiment of the deployable interbody implant 210 and comprises an upper shell 315, a lower shell 320, an upper hinge point 325, a lower hinge point 330, a proximal cage 350, a lateral projection 370, an angled slot 335, an angled slot 385, a dentate body 322, and an upper opening 312. An upper retaining projection 314 and a lower retaining projection 316 are also provided within the interbody implant 310. Similar to the intervertebral implant 210, the rotation point of the upper retaining projection 314 is the upper rod 365, and the rotation point of the lower retaining projection 316 is the lower rod 380. However, in the intervertebral implant 310, both the upper rod 365 and the lower rod 380 are configured to engage with the distal end of the adjustment screw 355. In one embodiment, the distal end of the adjustment screw 355 has a flange or groove toward the distal end of the adjustment screw 355 to accommodate the upper rod 365 and the lower rod 380. This engagement with the adjustment screw 355 allows the adjustment screw 355 to pull back the distal cage 345 so that the intervertebral implant 310 folds or at least partially folds. This configuration makes it possible to reduce the number of components required to achieve the desired deployment and contraction of the intervertebral implant 310.

[0066] Figure 12 further shows that the distal end of the adjustment screw 355 has a partially tapered tip. In one embodiment, this configuration reduces the amount of friction between the distal end of the adjustment screw 355 and the distal cage 345.

[0067] Figure 12 further shows a resistive element 333 having a screw-through hole configured to receive an adjustment screw 355 and resist unintended or undesirable rotation of the adjustment screw 355. The resistive element 333 is configured to be received by a proximal cage 350 and may contain a different material from the proximal cage 350. For example, the resistive element 333 may contain a polymer such as PEEK, in contrast to the proximal cage 350, which may contain a metal such as titanium or a titanium alloy.

[0068] Figure 13 shows an alternative embodiment of a deployable interbody implant 410 that differs from the deployable interbody implant 410 shown in this illustrated embodiment, which not only lacks the upper retaining projection 314 and the lower retaining projection 316, but also primarily consists of an adjustment screw 455 having a pair of screws, a first screw 455A and a second screw 455B. The first screw 455A has a screw hole that screws into and engages with the male thread of the second screw 455B. This configuration increases the amount of translation or movement of the distal cage 445 relative to the proximal cage 450. The first screw 455A is translated relative to the proximal cage 450 by rotating the first screw 455A, which screws into and engages with the screw hole 424 of the proximal cage 450. This rotation further translates the second screw 455B so that its distal end engages with the distal cage 445 and is rotated and secured to the distal cage 445 by the cross pin 455C. Next, the cross pin 455C is secured to the distal cage 445 by crimping the edge 455D of the hole into which the cross pin is inserted during assembly.

[0069] In one embodiment, using a pair of screws as shown in this illustrated embodiment reduces friction between the adjustment screw 455 and the distal cage 445, thereby reducing the torque required to deploy the intervertebral implant 410. In one embodiment, a cross pin 455C is not required to secure the second screw 455B to the distal cage 445, and this can be easily achieved by friction engagement with the distal end of the second screw 455B. However, the use of a cross pin 455C may facilitate closing the intervertebral implant 410, for example, when the intervertebral implant 410 needs to be repositioned or removed from the intervertebral space.

[0070] As in other embodiments disclosed herein, the intervertebral implant 410 comprises an upper rod 465 and a lower rod 480. As in some other embodiments, these rods are configured to slide in angled slots 435 and 485, respectively. This illustrated embodiment shows that these rods may be configured to engage with the upper shell 415 and the lower shell 420 only through their respective angled slots.

[0071] Similar to other embodiments, the upper shell 415 and the lower shell 420 have implantation windows and projections, dentate bodies, or anti-movement mechanisms 422. Furthermore, each shell has a hinge point at its proximal end, which in this embodiment has not only a curved surface but also a curved wall. Thus, each of the upper hinge point 425 and the lower hinge point 430 rotates around its respective proximal engagement mechanism in the proximal cage 450, but the additional curved wall can provide further stability to the intervertebral implant 410 as a whole.

[0072] Embodiment The following embodiments are provided only as examples of specific configurations, materials, arrangements, etc., considered by the authors of this disclosure.

[0073] Embodiment 1. An upper shell having a proximal end and a distal end, defining an upper surface that extends from the proximal end to the distal end and is configured to engage with the lower surface of a first vertebral body, further having a pair of side walls, and having a first angled slot that extends distally along the side wall away from the upper surface, A lower shell having a proximal end and a distal end, defining a lower surface that extends from the proximal end to the distal end and is configured to engage with the upper surface of a second vertebral body, further having a pair of side walls, and having a second angled slot in which at least one of the side walls extends distally in a direction away from the lower surface along the side wall, A control assembly positioned between an upper shell and a lower shell, having an interlocking proximal cage and a distal cage, and an adjustment screw that defines the longitudinal axis, wherein the proximal cage has a proximal hole and a distal hole, the distal cage has a proximal hole, and the adjustment screw extends through the distal hole of the proximal cage. It is equipped with, The proximal portion of the proximal cage has a pair of upper hinge points that are the rotation centers of the upper shell and a pair of lower hinge points that are the rotation centers of the lower shell. The distal cage has a first lateral projection configured to engage with a first angled slot, and a second lateral projection configured to engage with a second angled slot. A deployable intervertebral implant in which, by rotating an adjustment screw, the distal cage is translated parallel along the longitudinal axis, and then the distal ends of the upper and lower shells are separated from a deployed state to a deployed state.

[0074] Embodiment 2. The deployable intervertebral implant of Embodiment 1, wherein the adjustment screw is a pair of screws having a proximal screw and a distal screw, the proximal screw having a screw hole that opens at the distal end, and the distal screw screws into and engages with the screw hole.

[0075] Embodiment 3. A deployable intervertebral implant of Embodiment 2, wherein the distal end of a distal screw engages with the distal cage so that the distal screw rotates and locks relative to the distal cage.

[0076] Embodiment 4. A deployable intervertebral implant according to Embodiments 1, 2, or 3, wherein the distal opening of the proximal cage is threaded, and an adjustment screw engages with the threaded distal opening of the proximal cage by screwing.

[0077] Embodiment 5. A deployable intervertebral implant according to Embodiments 1, 2, 3, or 4, wherein the distal end of the adjustment screw is configured to contact the inner surface of the distal end of the distal cage.

[0078] Embodiment 6. A deployable intervertebral implant of Embodiments 1, 2, 3, 4, or 5, wherein the distal cage further comprises a retaining pin configured to hold an adjustment screw in a predetermined position longitudinally relative to the distal cage.

[0079] Embodiment 7. A deployable intervertebral implant of Embodiments 1, 2, 3, 4, 5, or 6, wherein the distal end of the adjustment screw is at least partially tapered.

[0080] Embodiment 8. The deployable intervertebral implant of Embodiment 1, wherein the distal cage further has a threaded distal bore, and an adjustment screw screws into and engages with the threaded distal bore.

[0081] Embodiment 9. The deployable intervertebral implant of Embodiment 8, wherein the proximal cage further comprises a retaining pin configured to hold an adjustment screw in a predetermined position longitudinally relative to the proximal cage.

[0082] Embodiment 10. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the distal cage further has a distal inclined surface configured to slide and engage with the respective inclined surfaces of the upper and lower shells.

[0083] Embodiment 11. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the distal cage further has a rounded upper surface and a rounded lower surface, respectively, configured to slide and engage with the lower surfaces of the upper and lower shells.

[0084] Embodiment 12. A deployable intervertebral implant of Embodiment 11, wherein the rounded upper and rounded lower surfaces are rods fixed to the distal cage.

[0085] Embodiment 13. The deployable intervertebral implant of Embodiment 12, wherein the rod functions as both the first and second lateral projections of the distal cage.

[0086] Embodiment 14. A deployable intervertebral implant of Embodiment 12 or 13, wherein the rod comprises a material having a coefficient of friction lower than that of the material forming the distal cage.

[0087] Embodiment 15. A deployable intervertebral implant of Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, further comprising expandable upper retaining projections and / or lower retaining projections configured to expand when the deployable intervertebral implant transitions from a non-deployed state to a deployed state.

[0088] Embodiment 16. A deployable intervertebral implant of Embodiment 15, wherein the upper retaining projection and / or lower retaining projection are configured to retract when the deployable intervertebral implant transitions from a deployed state to a non-deployed state.

[0089] Embodiment 17. The upper shell has an upper opening on its upper surface toward the distal end of the upper shell, and the upper opening is configured such that an expandable upper retaining projection can pass through the upper opening when expanded. A deployable intervertebral implant according to embodiment 15 or 16, wherein the lower shell has a lower opening on its lower surface toward the distal end of the lower shell, and the lower opening is configured such that an expandable lower retaining projection can pass through the lower opening when expanded.

[0090] Embodiment 18. A deployable intervertebral implant of Embodiment 15, 16, or 17, wherein the upper retaining projection and / or lower retaining projection are rotatably connected to the distal cage of the control assembly.

[0091] Embodiment 19. A deployable intervertebral implant of Embodiment 18, wherein the upper retaining projection and / or lower retaining projection expand or retract due to parallel movement of the distal cage along the longitudinal axis.

[0092] Embodiment 20. A deployable intervertebral implant according to Embodiments 15, 16, 17, 18, or 19, referencing Embodiments 12, 13, or 14, wherein the upper retaining projection and / or lower retaining projection are attached to the respective rods of the distal cage.

[0093] Embodiment 21. The deployable intervertebral implant of Embodiment 20, wherein the rod of the distal cage is configured to engage with the distal end of an adjustment screw having a radial recess for receiving at least a portion of the rod, and this engagement longitudinally fixes the distal cage to the adjustment screw.

[0094] Embodiment 22. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21, wherein the upper hinge point and the lower hinge point each have a lateral projection configured to engage with the proximal portion of the upper cage and the lower cage.

[0095] Embodiment 23. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22, wherein, when not deployed, the respective side walls of the upper and lower shells are in contact with each other and surround the control assembly.

[0096] Embodiment 24. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, or 23, wherein the distal ends of the upper and lower shells are curved to surround the distal end of the distal cage when the intervertebral implant is not deployed.

[0097] Embodiment 25. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24, wherein the upper shell, lower shell, proximal cage and distal cage each have at least one opening extending from the upper surface of the upper shell to the lower surface of the lower shell to define a channel for bone growth.

[0098] Embodiment 26. A deployable interbody implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25, wherein the deployable interbody implant comprises a titanium alloy.

[0099] Embodiment 27. A deployable intervertebral implant of Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 or 26, further comprising a resistance element configured to resist the rotation of an adjustment screw.

[0100] Embodiment 28. A deployable intervertebral implant of Embodiment 27, wherein the resistive element comprises a polymer.

[0101] Embodiment 29. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28, wherein at least one of the upper shell, lower shell, proximal cage, distal cage, and adjustment screw comprises a porous material.

[0102] Embodiment 30. A deployable intervertebral implant of Embodiment 29, wherein the porous material has two or more layers of porous sheets joined together to form a uniform material.

[0103] Embodiment 31. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, wherein the upper and lower shells are configured to be at least partially nested inside each other when the intervertebral implant is not deployed.

[0104] Embodiment 32. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, wherein the proximal and distal cages further have side walls configured to contact the inner surfaces of the respective side walls of the upper and lower shells to structurally support the intervertebral implant.

[0105] Embodiment 33. A deployable interbody implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 or 32, wherein the edge of at least one side wall of the upper shell has one or more projections, and the edge of at least one side wall of the lower shell has one or more recesses configured to receive one or more projections of the upper shell, so as to give greater structural integrity to the interbody implant when the interbody implant is not deployed.

[0106] Embodiment 34. A deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, or 33, wherein a layer of porous material is further provided on the upper surface of the upper shell and / or the lower surface of the lower shell, and the layer of porous material is located in a notch or recess on the upper and / or lower surface.

[0107] Embodiment 35. A deployable intervertebral implant of Embodiment 34, wherein the layer of porous material comprises one or more sheets of porous titanium alloy.

[0108] Embodiment 36. An insert for use with a deployable intervertebral implant of Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 or 35, A handle portion including an extension, the handle portion having a cannula that extends from the proximal end of the handle portion to the distal end of the extension, An engagement portion having an engagement mechanism provided at the distal end of the extension and configured to engage with an intervertebral implant, and at least one reverse torque extension portion configured to prevent rotation of the intervertebral implant while the engagement mechanism is engaged with or disengaged from the intervertebral implant, A deployment tool comprising a handle and an extension configured to slide and rotate within the cannula of the handle portion, the extension having a tip configured to extend into the intervertebral implant so as to engage with an adjustment screw. It is equipped with, An implant in which an intervertebral implant transitions from a non-deployed state to a deployed state, or from a deployed state to a non-deployed state, by the rotation of a deployment tool engaged with an adjustment screw.

[0109] Embodiment 37. The insert of Embodiment 36, wherein the handle further comprises an engagement knob configured to rotate the engagement mechanism.

[0110] Embodiment 38. The insert of Embodiment 36 or 37, wherein the handle further comprises a deployment indicator configured to show the degree of deployment of the intervertebral implant obtained by the rotation of the deployment tool.

[0111] Embodiment 39. The insertion of Embodiment 38, wherein the deployment tool is configured to give the initial degree of deployment of the intervertebral implant.

[0112] Embodiment 40. The insert of Embodiment 39, with an initial expansion degree greater than approximately 0°, greater than approximately 2°, greater than approximately 4°, or greater than approximately 6°.

[0113] Embodiment 41. A method for implanting a deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35, Using an insert, the intervertebral implant is placed in the intervertebral disc space in a folded state. By rotating the control knob on the insert, and then the adjustment screw, the intervertebral implant is deployed. A method for releasing a deployed intervertebral implant from the insertion device.

[0114] Embodiment 42. The method of Embodiment 41, wherein, before releasing the deployed intervertebral implant from the insert, a bone growth promoting material is injected into the intervertebral implant through an opening at the proximal end of the intervertebral implant.

[0115] Embodiment 43. A method for implanting a deployable intervertebral implant according to Embodiments 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35, Using the insert of Embodiment 36, 37, 38, 39, or 40, the intervertebral implant is placed in the intervertebral disc space in a folded state. By rotating the control knob on the insert, and then the adjustment screw, the intervertebral implant is deployed. A method for releasing a deployed intervertebral implant from the insertion device.

[0116] Embodiment 44. The method of Embodiment 43, wherein a bone growth promoting material is injected into the intervertebral implant through the proximal opening of the cannula before the deployed intervertebral implant is released from the insert.

[0117] While specific embodiments are shown and described herein, it should be understood that various other modifications and adjustments may be made without departing from the spirit and scope of the claimed subject matter. Furthermore, while various aspects of the claimed subject matter are described herein, these aspects do not need to be used in combination. Although the devices, systems, and methods described herein are described in a posterior approach, it should be noted that the devices, systems, and methods described herein may also be used in other surgical procedures, including lateral or anterior approaches.

[0118] Unless otherwise indicated, all numbers used in the specification and claims to represent quantities, properties, etc., such as molecular weight and reaction conditions of the components should be understood to be modified in all examples by the term “approximately”. Therefore, unless otherwise indicated, the numerical parameters described in the specification and the attached claims are approximations, which may vary depending on the desired properties sought to be obtained by embodiments of the present disclosure. At the very least, without attempting to limit the application of the principle of equivalents in the claims, each numerical parameter should be interpreted by applying ordinary rounding techniques, taking into account the number of significant figures stated. Although the numerical ranges and parameters representing the broad scope of the present disclosure are approximations, the numbers described in the specific examples are described as accurately as possible. However, every number inherently contains some error that inevitably arises from the standard deviation obtained in each test measurement. In one embodiment, the terms “approximately” and “about” refer to numerical parameters within 10% of the indicated range.

[0119] The terms “a,” “an,” “the,” and “the” and similar references used in relation to describing embodiments of this disclosure (particularly in relation to the following claims) should be construed to encompass both singular and plural unless otherwise specifically indicated herein or unless clearly inconsistent with the context. The enumeration of value ranges herein is merely intended to serve as a simple way to individually refer to each distinct value within that range. Unless otherwise specifically indicated herein, each individual value is incorporated into the specification as if it were individually described herein. All methods described herein may be performed in any appropriate order unless otherwise specifically indicated herein or unless clearly inconsistent with the context. The use of any and all examples or exemplary language (e.g., “etc.”) herein is merely intended to further illustrate embodiments of this disclosure and does not limit the scope of this disclosure. The language herein should not be construed to indicate any unclaimed elements essential to the implementation of embodiments of this disclosure.

[0120] The grouping of alternative elements or embodiments disclosed herein should not be construed as limiting. Each group member may be claimed individually or in any combination with other members of the group or other elements described herein. It is anticipated that one or more members of a group may be included in or removed from a group for convenience and / or patentability. In the event of any such inclusion or removal, the specification shall be deemed to include groups modified to satisfy the description of all Markush groups used in the appended claims.

[0121] This specification includes certain embodiments, including the best methods known to the inventors for carrying out embodiments of the present disclosure. Needless to say, variations of these described embodiments will be apparent to those skilled in the art by reading the above description. The inventors anticipate that those skilled in the art will appropriately adopt such variations and intend that embodiments of the present disclosure will be carried out in ways other than those specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter described in the claims attached to this application, as permitted by applicable patent law. Furthermore, any combination of the above-described elements of all possible variations is included in this disclosure unless specifically shown herein or is obviously inconsistent with the context.

[0122] The specific embodiments disclosed herein may be further limited in the claims using the phrases “composed of” or “essentially composed of.” When used in the claims, whether filed or added with each amendment, the transitional phrase “composed of” excludes any elements, processes or components not specified in the claims. The transitional phrase “essentially composed of” limits the claims to the specified materials or processes and any materials or processes that do not significantly affect one or more fundamental novel properties. Embodiments of the disclosure thus claimed are essentially or expressly described herein and made possible.

[0123] Furthermore, if any reference is made to patents and publications through this disclosure, each of these references and publications is individually incorporated herein by reference in whole.

[0124] Finally, the embodiments disclosed herein should be understood as examples of the principles of the disclosure. Other modifications that may be adopted are within the scope of the disclosure. Accordingly, alternative configurations of the embodiments of the disclosure may be used in accordance with the teachings herein, without limiting them to examples. Thus, the disclosure is not limited to those precisely shown and described herein.

[0125] Related applications This application claims priority to U.S. Provisional Application No. 62 / 985610, filed on 5 March 2020, and U.S. Provisional Application No. 63 / 062663, filed on 7 August 2020, both of which are incorporated herein by reference in their entirety.

Claims

1. an upper shell having a proximal end and a distal end, defining an upper surface extending from said proximal end to said distal end and configured to engage an inferior surface of a first vertebral body, and further having a pair of side walls, at least one of the side walls having a first angled slot extending distally along said side wall and away from said upper surface; a lower shell having a proximal end and a distal end, defining a lower surface extending from said proximal end to said distal end and configured to engage an upper surface of a second vertebral body, and further having a pair of side walls, at least one of the side walls having a second angled slot extending distally along said side wall and away from said lower surface; a control assembly disposed between the upper and lower shells, the control assembly having interlocking proximal and distal cages and an adjustment screw defining a longitudinal axis, the proximal cage having a proximal bore and the distal cage having a proximal bore, the adjustment screw extending through the distal bore of the proximal cage; It is equipped with a proximal portion of the proximal cage having a pair of upper hinge points about which the upper shell rotates and a pair of lower hinge points about which the lower shell rotates; the distal cage having a first lateral projection configured to engage the first angled slot and a second lateral projection configured to engage the second angled slot; An expandable interbody implant, wherein rotation of the adjustment screw causes the distal cage to translate along the longitudinal axis, which in turn moves the distal ends of the upper and lower shells apart from an undeployed state to a deployed state.

2. 2. The expandable interbody implant of claim 1, wherein the adjustment screws are twin screws having a proximal thread and a distal thread, the proximal thread having a threaded hole opening at a distal end and the distal thread threadingly engaging the threaded hole.

3. The expandable interbody implant of claim 2 , wherein a distal end of the distal screw engages the distal cage such that the distal screw is rotationally fixed relative to the distal cage.

4. The expandable interbody implant of claim 1 , wherein the distal hole of the proximal cage is threaded and the adjustment screw threadably engages the threaded distal hole of the proximal cage.

5. The expandable interbody implant of claim 1 , wherein a distal end of the adjustment screw is configured to abut an interior surface at a distal end of the distal cage.

6. The expandable interbody implant of claim 1 , wherein the proximal cage further comprises a retaining pin configured to hold the adjustment screw in a predetermined longitudinal position relative to the proximal cage.

7. 10. The expandable interbody implant of claim 1, wherein the distal cage further comprises a distal angled surface configured for sliding engagement with respective angled surfaces on the upper and lower shells.

8. 10. The expandable interbody implant of claim 1, wherein the distal cage further comprises rounded upper and lower surfaces configured for sliding engagement with inner surfaces of the upper and lower shells, respectively.

9. The expandable interbody implant of claim 8 , wherein the rounded upper surface and the rounded lower surface are provided with rods secured to the distal cage.

10. The expandable interbody implant of claim 9 , wherein the rod functions as both a first lateral projection and a second lateral projection of the distal cage.

11. The expandable interbody implant of claim 9 , wherein the rod comprises a material having a coefficient of friction lower than a coefficient of friction of a material forming the distal cage.

12. 10. The expandable interbody implant of claim 1, further comprising expandable upper and / or lower retention protrusions configured to expand when the expandable interbody implant transitions from an undeployed state to a deployed state.

13. 13. The expandable interbody implant of claim 12, wherein the upper retention protrusions and / or the lower retention protrusions are configured to retract when the expandable interbody implant transitions from a deployed state to an undeployed state.

14. the upper shell has an upper opening on the upper surface toward a distal end of the upper shell, the upper opening being configured to allow an expandable upper retention protrusion to pass through the upper opening when expanded; 13. The expandable interbody implant of claim 12, wherein the lower shell has a lower opening on the lower surface toward a distal end of the lower shell, the lower opening configured to allow an expandable lower retention protrusion to pass through the lower opening when expanded.

15. 13. The expandable interbody implant of claim 12, wherein the upper retention protrusion and / or the lower retention protrusion are pivotally coupled to a distal cage of the control assembly.

16. 16. The expandable interbody implant of claim 15, wherein translation of the distal cage along the longitudinal axis causes the upper and / or lower retention protrusions to expand or retract.

17. the distal cage further includes rounded upper and lower surfaces configured to slidingly engage inner surfaces of the upper and lower shells, respectively; the rounded upper surface and the rounded lower surface are provided with rods secured to the distal cage; 13. The expandable interbody implant of claim 12, wherein the upper and / or lower retaining protrusions are attached to respective rods of the distal cage.

18. 10. The expandable interbody implant of claim 1, wherein in an undeployed state, the side walls of the upper and lower shells abut one another to enclose the control assembly.

19. 2. The expandable interbody implant of claim 1, wherein the distal ends of the upper and lower shells are curved to surround the distal end of the distal cage when the interbody implant is in an undeployed state.

20. The expandable interbody implant of claim 1 , wherein at least one of the upper shell, the lower shell, the proximal cage, the distal cage, and the adjustment screw comprises a porous material.

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