Patent Publication Number: US-2021186706-A1

Title: Expandable intervertebral implant

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/950,180, entitled EXPANDABLE THREADED INTERVERTEBRAL IMPLANT, which was filed on Dec. 19, 2019, which is incorporated by reference as though set forth herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to surgical devices. More specifically, the present disclosure relates to improved surgical devices for implanting expandable intervertebral implants between adjacent vertebral bodies in a patient. 
     BACKGROUND 
     Spinal fixation procedures utilizing expandable intervertebral implants can be used to correct spinal conditions such as degenerative disc disease, spondylolisthesis, spinal deformities, or other spinal conditions through minimally invasive or invasive spinal surgery. For example, intervertebral discs can degenerate or otherwise become damaged over time. In some instances, an expandable intervertebral implant can be positioned within a space previously occupied by a disc between adjacent vertebral bodies. Such expandable intervertebral implants can help maintain a desired spacing between adjacent vertebrae and/or promote fusion between adjacent vertebrae. The use of bone graft and/or other materials within an area that includes an expandable intervertebral implant can also facilitate the fusion of adjacent vertebral bodies. Accordingly, a need exists for improved expandable intervertebral implants. 
     SUMMARY 
     The various apparatus, devices, systems, and/or methods of the present disclosure have been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available expandable intervertebral implants. The apparatus, devices, systems, and/or methods of the present disclosure may provide interspinous-interlaminar stabilization systems and methods that remedy shortcomings of prior art expandable intervertebral implants. 
     To achieve the foregoing, and in accordance with the disclosure as embodied and broadly described herein, an expandable intervertebral implant may be provided. One general aspect of the expandable intervertebral implant can include an upper plate that may include a first upper side and a second upper side, a lower plate that may include a first lower side and a second lower side, a first lattice that connects the first upper side of the upper plate to the first lower side of the lower plate, a second lattice that connects the second upper side of the upper plate to the second lower side of the lower plate, and an opening having a longitudinal axis between the upper plate, lower plate, first lattice, and second lattice. The expandable intervertebral implant may also include an expansion mechanism that may include a driver that expands the upper plate and the lower plate away from each other along a cephalad-caudal axis by deforming the first lattice and the second lattice. 
     In one aspect, the opening may have internal threads about the longitudinal axis. In addition, the expansion mechanism can include a screw member that may include a shank having threads that engage the internal threads within the opening. In addition, the screw member can have a diameter selected such that rotation of the screw member about the longitudinal axis by activation of the driver separates the upper plate from the lower plate by deforming the first lattice and the second lattice. 
     The driver of the expansion mechanism may include a head of the screw member connected to a proximal end of the shank. The screw member may include a tapered end connected to a distal end of the shank and the screw member may have a cross-sectional diameter greater than a height of the opening. The cross-sectional diameter of the screw member can be greater than a width of the opening. 
     In one aspect, the expansion mechanism may include a set of screw members and each can have a shank that includes threads that engage the internal threads within the opening. Each screw member of the set of screw members can have a different cross-sectional diameter. 
     The upper plate may have an upper lattice and the lower plate may have a lower lattice. The expansion mechanism can be configured such that activation of the expansion mechanism by the driver expands the upper plate and the lower plate away from each other along the cephalad-caudal axis. In addition, or alternatively, activation of the expansion mechanism may also move the first lattice and the second lattice away from each other along a medial-lateral axis by deforming the first lattice, the second lattice, the upper lattice, and the lower lattice. 
     The opening may have an ovoid cross-section that may have a height that is different from a width of the ovoid cross-section. 
     The first lattice and the second lattice may be made of metal. The first lattice and the second lattice each have a common pattern. The pattern, and/or the common pattern, may have one or more of a set of geometric shapes that include pores. 
     One general aspect can include an expandable intervertebral implant that may have an upper plate that may have an upper mesh, a first upper side, and a second upper side, a lower plate that may have a lower mesh, a first lower side, and a second lower side, a first wall that connects the first upper side of the upper plate to the first lower side of the lower plate, the first wall may have a first mesh, a second wall that connects the second upper side of the upper plate to the second lower side of the lower plate, the second wall may have a second mesh, an opening having a longitudinal axis between the upper plate, the lower plate, the first wall, and the second wall, and an expansion mechanism that may have a driver that expands the upper plate and the lower plate away from each other along a cephalad-caudal axis by expanding the first mesh and the second mesh and moves the first wall and the second wall away from each other along a medial-lateral axis by expanding the upper mesh and the lower mesh. 
     Certain embodiments may include one or more of the following aspects. The opening may have internal threads about the longitudinal axis and the expansion mechanism may have a screw member that may include a shank that may have threads that engage the internal threads within the opening, the screw member having a diameter selected such that rotation of the screw member about the longitudinal axis by activation of the driver expands, the first mesh, the second mesh, the upper mesh, and the lower mesh. 
     The opening may have an elliptical cross-section that may have a height that is smaller than a width of the elliptical cross-section. The first mesh and the second mesh may each have a first pattern. The first pattern and the height of the elliptical cross-section of the opening may each be selected such that activation of the driver of the expansion mechanism causes a predetermined increase in distance, a predetermined spacing, between the upper plate and the lower plate. 
     In one aspect, the first mesh and the second mesh may each have a first pattern and the upper mesh and the lower mesh may each have a second pattern. The first pattern and the second pattern may each be selected such that activation of the driver of the expansion mechanism causes a first predetermined increase in a distance between the upper plate and the lower plate that differs from a second predetermined increase in a distance between the first wall and the second wall. 
     The expandable intervertebral implant may have a proximal end and a distal end. The first mesh may span the first wall from the first upper side to the first lower side and from the proximal end to the distal end of the expandable intervertebral implant. The second mesh may span the second wall from the second upper side to the second lower side and from the proximal end to the distal end of the expandable intervertebral implant. The upper mesh may span the upper plate from the first upper side to the second upper side and from the proximal end to the distal end of the expandable intervertebral implant. The lower mesh may span the lower plate from the first lower side to the second lower side and from the proximal end to the distal end of the expandable intervertebral implant. 
     One general aspect can include an expandable intervertebral implant that may have an upper plate that may have an upper lattice, a first upper side, and a second upper side, a lower plate that may have a lower lattice, a first lower side and a second lower side, a first lattice that connects the first upper side of the upper plate to the first lower side of the lower plate, a second lattice that connects the second upper side of the upper plate to the second lower side of the lower plate, an opening having internal threads about a longitudinal axis between the upper plate, the lower plate, the first lattice, and the second lattice, and a screw member that may have a shank that may have threads that engage the internal threads within the opening, the screw member having a diameter such that rotation of the screw member about the longitudinal axis separates the upper plate from the lower plate by deforming the first lattice and the second lattice and separates the first lattice from the second lattice by deforming the upper lattice and the lower lattice. 
     The upper plate, the lower plate, the first lattice, and the second lattice may be made from titanium. The first lattice and the second lattice may each include a first pattern, a size of the opening, and a diameter of the screw member selected such that that rotation of the screw member about the longitudinal axis moves the screw member within the opening and expands the expandable intervertebral implant along a cephalad-caudal axis and along a medial-lateral axis to a target expanded configuration. 
     Certain embodiments, of the expandable intervertebral implant may further include a proximal end, a distal end, and an inserter attachment feature connected to the upper plate, the lower plate, the first lattice, and the second lattice at the proximal end. The upper lattice, the lower lattice, the first lattice, and the second lattice each extend to include the inserter attachment feature. In other words, a pattern for one or more of the upper lattice, the lower lattice, the first lattice, and the second lattice may also be formed within one or more walls of the inserter attachment feature. 
     These and other features and advantages of the present disclosure will become more fully apparent from the following description and appended claims or may be learned by the practice of the disclosure as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the scope of the appended claims, the exemplary embodiments of the present disclosure will be described with additional specificity and detail through use of the accompanying drawings in which: 
         FIG. 1A  is a perspective top view of a proximal end of an expandable intervertebral implant  100 , according to one embodiment of the present disclosure; 
         FIG. 1B  is a perspective top view of a distal end of the expandable intervertebral implant  100  of  FIG. 1A ; 
         FIG. 2A  is a perspective top view of a proximal end of an expandable intervertebral implant  200 , according to one embodiment of the present disclosure; 
         FIG. 2B  is a perspective top view of a distal end of the expandable intervertebral implant  200  of  FIG. 2A ; 
         FIG. 3A  is a perspective top view of a proximal end of an expandable intervertebral implant  300 , according to one embodiment of the present disclosure; 
         FIG. 3B  is a perspective top view of a distal end of the expandable intervertebral implant  300  of  FIG. 3A ; 
         FIG. 3C  is a side elevation view of the expandable intervertebral implant  300  of  FIG. 3A ; 
         FIG. 3D  is a plan view of the expandable intervertebral implant  300  of  FIG. 3A ; 
         FIG. 4A  is a perspective view of a distal end of an expansion mechanism according to one embodiment of the present disclosure; 
         FIG. 4B  illustrates a side elevation view of the expansion mechanism of  FIG. 4A ; 
         FIG. 5A  is an exploded view of the expandable intervertebral implant  300  of  FIG. 3A  with the screw member of  FIG. 4A ; 
         FIG. 5B  is perspective view of the expandable intervertebral implant  300  of  FIG. 3A  in an expanded configuration with the screw member of  FIG. 4A  within the expanded configuration  300 ; 
         FIG. 5C  is a side elevation view of the expandable intervertebral implant  300  of  FIG. 3A  in an expanded configuration; 
         FIG. 5D  is a plan view of the expandable intervertebral implant  300  of  FIG. 3A  in an expanded configuration; 
         FIG. 5E  illustrates a proximal end view of the expandable intervertebral implant  300  of  FIG. 5A  in a collapsed configuration and a screw member; 
         FIG. 5F  illustrates a distal end view of the expandable intervertebral implant  300  of  FIG. 5A  in a collapsed configuration and a screw member; 
         FIG. 5G  illustrates a proximal end view of the expandable intervertebral implant  300  of  FIG. 5A  in an expanded configuration with a screw member; 
         FIG. 5H  illustrates a distal end view of the expandable intervertebral implant  300  of  FIG. 5A  in an expanded configuration with a screw member; 
         FIGS. 6A-6F  illustrates different patterns that can be used in various embodiments of the present disclosure; and 
         FIGS. 7A-7C  illustrates different patterns that can be used in various embodiments of the present disclosure. 
     
    
    
     It is to be understood that the drawings are for purposes of illustrating the concepts of the disclosure and may not be drawn to scale. Furthermore, the drawings illustrate exemplary embodiments and do not represent limitations to the scope of the present disclosure. 
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present disclosure, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus and method, as represented in the Figures, is not intended to limit the scope of the present disclosure, as claimed in this or any other application claiming priority to this application, but is merely representative of exemplary embodiments of the present disclosure. 
     Standard medical directions, planes of reference, and descriptive terminology are employed in this specification. For example, anterior means toward the front of the body. Posterior means toward the back of the body. Superior means toward the head. Inferior means toward the feet. Medial means toward the midline of the body. Lateral means away from the midline of the body. Axial means toward a central axis of the body. Abaxial means away from a central axis of the body. Ipsilateral means on the same side of the body. Contralateral means on the opposite side of the body. A sagittal plane divides a body into right and left portions. A midsagittal plane divides the body into bilaterally symmetric right and left halves. A coronal plane divides a body into anterior and posterior portions. A transverse plane divides a body into superior and inferior portions. These descriptive terms may be applied to an animate or inanimate body. 
     The phrases “connected to,” “coupled to” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be functionally coupled to each other even though they are not in direct contact with each other. The term “abutting” refers to items that are in direct physical contact with each other, although the items may not necessarily be attached together. The phrase “fluid communication” refers to two features that are connected such that a fluid within one feature is able to pass into the other feature. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated. 
     The present disclosure discloses an expandable intervertebral implant. Medical procedures for using expandable intervertebral implants favor an expandable intervertebral implant that is small and compact. For example, minimally invasive or invasive surgery on the spine, such as spinal fusion, may be use a variety of approaches to access the spine, examples include Anterior Lumbar Interbody Fusion (ALIF), Posterior Lumbar Interbody Fusion (PLIF), or Lateral Interbody Fusion (LIF). For each of these spinal procedures, a smaller implant that can be expanded, as needed, to a desired height and/or width, is preferred because the smaller expandable intervertebral implants can cause less disruption of soft tissue and smaller access openings can be used for the procedures. 
     For example, using a smaller expandable intervertebral implant for minimally invasive spine (MIS) surgery techniques can reduce the size of the incisions, soft tissue damage, blood loss, less intrusive implants, post-operative pain, recovery time, risk of surgical complications, and the like. Furthermore, the shape, or profile, of an expandable intervertebral implant can facilitate insertion of the implant during the surgery and provide more stable and secure engagement between the implant and vertebral bodies on either side of a space where the implant is positioned. 
     For example, using a smaller expandable intervertebral implant having fewer parts can result in a more reliable and effective expandable intervertebral implant. Expandable intervertebral implant with fewer parts can be less expensive to fabricate and can be less prone to failure. These and other unique features of the expandable intervertebral implant are discussed below and illustrated in the accompanying drawings. 
     For example, in one embodiment, the expandable intervertebral implant may have two parts, a structure for the expandable intervertebral implant and an expansion mechanism, such as a screw member. An expandable intervertebral implant that includes just a structure that forms the expandable intervertebral implant, and the expansion mechanism can be simpler than other implants and can be easier to operate and install during a surgical procedure. In addition, certain embodiments of the expandable intervertebral implant may include an expansion mechanism that includes a plurality of screw members, each having a different diameter. In such an embodiment, a surgeon can choose which diameter screw member to use to achieve a target expanded configuration. Of course, one skilled in the art may recognize other situations and advantages of an expandable intervertebral implant having a minimal number of parts; this disclosure contemplates all such situations and advantages. 
     Similarly, an expandable intervertebral implant having fewer parts may be fabricated with smaller dimensions in a collapsed configuration. A smaller expandable intervertebral implant can enable MIS surgery techniques that use a narrower incision and/or narrower cannulas to perform the procedure. A smaller expandable intervertebral implant can facilitate positioning and placement of the implant. In certain circumstances two or more expandable intervertebral implants may be used to provide desired support for vertebral bodies. 
       FIG. 1A  is a perspective view depicting one exemplary embodiment of an expandable intervertebral implant  100 . The expandable intervertebral implant  100  may generally include an upper plate  110  configured to engage a superior vertebral body (not shown), a lower plate  120  configured to engage an inferior vertebral body (not shown), a first lattice  130 , a second lattice  140 , an opening  150 , and an expansion mechanism  160 . The expandable intervertebral implant  100  can further include a proximal end  170  and a distal end  180 . 
     As used herein, a “plate” refers to a flat structure. In certain embodiments, a plate can be configured to support a load. In certain embodiments, a plate may comprise a generally planar structure. A plate can be a separate structure connected to, or integrated with, another structure. Alternatively, a plate can be connected to part of another structure. A plate be two-dimensional or three-dimensional and can have a variety of geometric shapes and/or cross-sectional shapes, including, but not limited to a rectangle, a square, or other polygon, as well as a circle, an ellipse, an ovoid, or other circular or semi-circular shape. A plate can be made from a variety of materials including, metal, plastic, ceramic, wood, fiberglass, or the like. 
     One plate may be distinguished from another based on where the plate is positioned within a structure, component, or apparatus. For example, an “upper plate” can include a plate positioned on, near, or integrated with, a structure such that the plate is at, or near, a top of the structure. Similarly, a “lower plate” can include a plate positioned on, near, or integrated with, a structure such that the plate is at, or near, a bottom of the structure. 
     In the illustrated embodiment, the upper plate  110  can be a superior structure of the expandable intervertebral implant  100 . The upper plate  110  can be a three-dimensional rectangular structure having a generally planar external surface. The lower plate  120  can be an inferior structure of the expandable intervertebral implant  100 . The lower plate  120  can be a three-dimensional rectangular structure having a generally planar external surface. In the illustrated embodiment, the upper plate  110  and lower plate  120  can have the same or a similar length and width. 
     The upper plate  110  may include a first upper side  112  and a second upper side  114 . As used herein, a “side” refers to a location on a structure. In general, a side is a location on a structure at, or near, a furthest position away from a central axis of the structure. In one embodiment, the first upper side  112  is at, or near, a longitudinal edge of the upper plate  110  and the second upper side  114  is at, or near, an opposite longitudinal edge of the upper plate  110 . 
     The lower plate  120  may include a first lower side  122  and a second lower side  124  (See  FIG. 1B ). In one embodiment, the first lower side  122  is at, or near, a longitudinal edge of the lower plate  120  and the second lower side  124  is at, or near, an opposite longitudinal edge of the lower plate  120 . 
     The first lattice  130  can form one wall of the expandable intervertebral implant  100 . As used herein, a “lattice” refers to a three-dimensional planar structure having a plurality of pores distributed within a longitudinal plane of the structure. Furthermore, the pores of the lattice are configured to expand and/or compress in response to a tensile force or compressive force applied in opposite directions and at opposite ends of the lattice. In particular embodiments, structures of the lattice that interconnect the pores are configured and made of a material that is elastic such that lattice expands its overall shape in response to tensile force(s) and or contracts its overall shape in response to compressive force(s). In certain embodiments, a tensile force on the lattice in opposite directions and at opposite ends causes the lattice to deform, or stretch, to have a greater surface area. 
     In certain embodiments, the pores of the lattice comprise at least one shape. For example, in one embodiment, each of the pores can have a geometric shape, a polygon shape, a circular shape, an ovoid shape, an elliptical shape, and the like. In certain embodiments, a “lattice” may comprise a “mesh.” As used herein, a “mesh” refers to a three-dimensional planar structure having a plurality of openings distributed within a longitudinal plane of the structure. Each of the plurality of openings of the mesh may be of a common shape. Alternatively, or in addition, the plurality of openings of a mesh may include openings having two or more geometric shapes. 
       FIG. 1A  illustrates the first lattice  130  in general without the pores specifically illustrated, at least in part, because the first lattice  130  can have a variety of different kinds, types, sizes, numbers, formats, designs, and distribution arrangements of the pores. Thus,  FIG. 1A  illustrates a generic lattice for the first lattice  130  and/or  FIG. 1B  illustrates a generic lattice for the second lattice  140 . A few variations and/or embodiments for the first lattice  130  and/or second lattice  140  will be described in more detail herein, however, the claims of this disclosure are not limited to the embodiments illustrated or described. 
       FIG. 1A  illustrates that the first lattice  130  provides structural support and definition to the expandable intervertebral implant  100  and connects the first upper side  112  of the upper plate  110  to the first lower side  122  of the lower plate  120 . 
       FIG. 1B  illustrates that the second lattice  140  provides structural support and definition to the expandable intervertebral implant  100  and connects the second upper side  114  of the upper plate  110  to the second lower side  124  of the lower plate  120 . 
     The expandable intervertebral implant  100  can include an opening  150 . As used herein, an “opening” refers to a gap, a hole, an aperture, a void in a structure, or the like. In certain embodiments, an opening can refer to a structure configured specifically for receiving something and/or for allowing access. In one embodiment, the opening  150  extends from the proximal end  170  to the distal end  180  of the expandable intervertebral implant  100 . The opening  150  can include a longitudinal axis  152  that extends from one end of the opening  150  to the other. The opening  150  is between the upper plate  110 , the lower plate  120 , the first lattice  130 , and the second lattice  140 . In certain embodiments, the longitudinal axis  152  can run through a geometric center of a cross-section of the opening  150 . 
     In certain embodiments, the opening  150  is configured and/or sized to receive an expansion mechanism  160  and/or a component of an expansion mechanism  160  (See  FIG. 5A ). As will be appreciated by those of skill in the art, in this disclosure, the opening  150  can receive a variety of different types of expansion mechanisms  160 . In the illustrated embodiment, the opening  150  includes internal threads  154  about the longitudinal axis  152 . The internal threads  154  can be configured and arranged to engage with threads of an expansion mechanism  160 . One exemplary expansion mechanism  160  is described in more detail in relation to subsequent Figures. Other suitable examples of an expansion mechanism  160  include, but are not limited to a peg, a wedge, a pin, or the like. Those of skill in the art may recognize other suitable expansion mechanisms  160  that can be used in connection with the opening  150 . 
     In certain embodiments, the expansion mechanism  160  can include a driver  162  (See  FIG. 5A ). A driver  162  is a component of the expansion mechanism  160  configured to expand or contract the expansion mechanism  160  when the driver  162  is activated or de-activated. In one embodiment, the driver  162  is configured to expand the upper plate  110  and the lower plate  120  away from each other along a cephalad-caudal axis (See  FIG. 5A ) by deforming the first lattice  130  and the second lattice  140 . Further description of the driver is provided in relation to  FIGS. 4A,5A . 
       FIG. 1A  is a perspective top view from the proximal end  170  of the expandable intervertebral implant  100  and  FIG. 1B  is a perspective top view from the distal end  180  of the expandable intervertebral implant  100  of  FIG. 1A . The distal end  180  of the expandable intervertebral implant  100  is an end that first enters the space between two vertebral bodies as a surgeon installs the expandable intervertebral implant  100 . The proximal end  170  of the expandable intervertebral implant  100  is an end of the expandable intervertebral implant  100  closest to a surgeon installing the expandable intervertebral implant  100  between two vertebral bodies. The proximal end  170  is near an end of the expandable intervertebral implant  100  that includes a removably connects to an insertion tool used to install the expandable intervertebral implant  100 . 
     In certain embodiments, the expandable intervertebral implant  100  and its components can be made from the same material. Alternatively, or in addition, the upper plate  110 , lower plate  120 , first lattice  130 , and second lattice  140  can be made from different materials. For example, the first lattice  130  and second lattice  140  can be made from a material having a different plasticity than the upper plate  110  and/or lower plate  120 . In one embodiment, the first lattice  130  and second lattice  140  can be made from a material having a common plasticity such that first lattice  130  and second lattice  140  deform together under and expansion force created by the expansion mechanism  160 . 
     The expandable intervertebral implant  100  and/or its constituent components may be formed of any biocompatible materials, including but not limited to biocompatible metals such as Titanium, Titanium alloys, stainless steel alloys, cobalt-chromium steel alloys, nickel-titanium alloys, shape memory alloys such as Nitinol, biocompatible ceramics, and biocompatible polymers such as Polyether ether ketone (PEEK) or a polylactide polymer (e.g. PLLA) and/or others. In one embodiment, the first lattice  130  and/or the second lattice  140  can be made of metal. In some embodiments, components of the expandable intervertebral implant  100  may be formed of a less rigid material so that the upper plate  110  and/or lower plate  120  can spread apart from each other in response to the expansion mechanism  160 . 
     The expandable intervertebral implant  100  and/or its constituent components may be manufactured using any known manufacturing method, including casting, forging, milling, additive manufacturing, and/or the like. As used herein, “additive manufacturing” refers to a manufacturing process in which materials are joined together in a process that repeatedly builds one layer on top of another to generate a three-dimensional structure or object. Additive manufacturing may also be referred to using different terms including: additive processes, additive fabrication, additive techniques, additive layer manufacturing, layer manufacturing, freeform fabrication, ASTM F2792 (American Society for Testing and Materials), and 3D printing. Additive manufacturing can build the three-dimensional structure or object using computer-controlled equipment that applies successive layers of the material(s) based on a three-dimensional model that may be defined using Computer Aided Design (CAD) software. Additive manufacturing can use a variety of materials including polymers, thermoplastics, metals, ceramics, biochemicals, and the like. Additive manufacturing may provide unique benefits, as the expandable intervertebral implant  100  together with the pores of the lattices  130 / 140  can be directly manufactured (without the need to generate molds, tool paths, perform any milling, and/or other manufacturing steps). 
       FIG. 2A  is a perspective top view of a proximal end of an expandable intervertebral implant  200 , according to one embodiment of the present disclosure. In the illustrated embodiment, like parts are identified by common numbers in other figures. The embodiment of  FIG. 2A  includes an upper plate  110 , a lower plate  120 , a first lattice  130 , a second lattice  140 , an opening  150 , and an expansion mechanism  160  as described in relation to  FIGS. 1A and 1B . 
     In addition,  FIGS. 2A and 2B  illustrate details of the first lattice  130  and the second lattice  140 . Specifically, the first lattice  130  and the second lattice  140  each have a pattern. As used herein, “pattern” refers to a repeated set of shape, shapes, or design within or upon a planar structure. In certain embodiments, the pattern defines the number, size, position, layout, and distribution of shapes of the lattice. The shapes of the pattern for the lattice can include the openings and/or pores of the lattice. In one embodiment, the pattern includes a distributed set of pores, or shapes, or openings, that include one or more geometric shapes of a set of geometric shapes. In certain embodiments, the set of pores of the opening is uniformly distributed. In other embodiments, the set of pores of the opening is non-uniformly distributed. 
     In one embodiment, the pattern for the first lattice  130  can be different from the pattern for the second lattice  140 . In another embodiment, the first lattice  130  and second lattice  140  both have a common pattern. In the illustrated exemplary embodiment, the first lattice  130  and the second lattice  140  each include a pattern of pores/openings shaped as hexagons. 
     In an embodiment, where the first lattice  130  and second lattice  140  both have the same pattern or a common pattern, activation of the expansion mechanism  160  can cause both the first lattice  130  and the second lattice  140  to expand in an even, uniform, and predictable manner. Consequently, the upper plate  110  and lower plate  120  can maintain a parallel relationship to each other when the expansion mechanism  160  changes the expandable intervertebral implant  100  from a collapsed configuration to an expanded configuration. 
       FIG. 3A  is a perspective top view of a proximal end  170  of an expandable intervertebral implant  300 , according to one embodiment of the present disclosure.  FIG. 3B  is a perspective top view of a distal end  180  of the expandable intervertebral implant  300  of  FIG. 3A . In the illustrated embodiment, like parts are identified by common numbers in other figures. The embodiment of  FIG. 3A  includes an upper plate  110 , a lower plate  120 , a first lattice  130 , a second lattice  140 , an opening  150 , and an expansion mechanism  160  as described in relation to  FIGS. 1A and 1B . 
     In addition, as illustrated in the expandable intervertebral implant  300  of  FIG. 3A , the upper plate  110  includes an upper lattice  310  and the lower plate  120  includes a lower lattice  320 . In certain embodiments, the upper lattice  310  and lower lattice  320  can have the same pattern as the first lattice  130  and/or second lattice  140 . Alternatively, the upper lattice  310  and lower lattice  320  can each have a common pattern different from one of the patterns of the first lattice  130  and/or second lattice  140 . 
     As will be discussed in more detail later, the upper lattice  310  and lower lattice  320  enable expansion of the first lattice  130  and the second lattice  140  away from each other along a medial-lateral axis (shown in  FIG. 5A ). In this manner, the expandable intervertebral implant  300  is configured to expand in four directions when the expansion mechanism  160  is activated. 
     In certain embodiments, the upper plate  110  includes a plurality of teeth  330  and a plurality of grooves  340 . The plurality of teeth  330  can connect to the upper plate  110  along a surface of the upper plate  110 . The plurality of grooves  340  can run perpendicular to the plurality of teeth  330 . The plurality of teeth  330  and plurality of grooves  340  can serve to engage a superior vertebral body. 
     Similarly, the lower plate  120  can include a plurality of teeth  330  and a plurality of grooves (See  FIG. 3C ). The plurality of teeth  330  can connect to the lower plate  120  along a surface of the lower plate  120 . The plurality of teeth  330  serve to engage an inferior vertebral body. The number of teeth  330  and/or their positions on the upper plate  110  and/or lower plate  112  may vary in certain embodiments of an expandable intervertebral implant  100 ,  200 ,  300 . In the illustrated embodiment of  FIGS. 1A-3D , the teeth  330  each point towards the proximal end  170 . Of course, those of skill in the art recognize that other positions, patterns, placement and spacing of the plurality of teeth  330  and/or the plurality of grooves  340  may be used with the expandable intervertebral implant disclosed herein. 
       FIG. 3C  is a side elevation view of the expandable intervertebral implant  300  of  FIG. 3A  and  FIG. 3D  is a plan view of the expandable intervertebral implant  300  of  FIG. 3A . In certain embodiments, the expandable intervertebral implant  300  is symmetrical between its upper plate  110  and lower plate  120  and between its first lattice  130  and second lattice  140 . Therefore, as  FIG. 3C  illustrates a second lattice  140  and  FIG. 3D  illustrates a upper plate  110 , those of skill in the art will recognize and understand the configuration of the symmetrical first lattice  130  and lower plate  120 . 
     Referring to  FIGS. 3A-3D , in certain embodiments, a first wall  350  can be used in place of a first lattice  130  and a second wall  352  used in place of a second lattice  140 . The first wall  350  can include a first mesh  360  and the second wall  352  can include a second mesh  362 . In addition, an upper mesh  370  can be used in place of an upper lattice  310  and a lower mesh  380  in place of a lower lattice  320 .  FIG. 3A  illustrates the second lattice  140  or second wall  352 . Similarly,  FIG. 3B  illustrates an upper lattice  310  or upper mesh  370 . 
       FIG. 3C  illustrates that the lattice or mesh of wall may extend from a proximal end  170  to a distal end  180  of the expandable intervertebral implant  300 . Similarly,  FIG. 3D  illustrates that the upper mesh and/or lower mesh of an upper plate  110  and/or lower plate  120  may extend from the proximal end  170  to the distal end  180 . 
       FIG. 4A  is a perspective view of a distal end of an expansion mechanism  160  according to one embodiment of the present disclosure. The expansion mechanism  160  may be formed of any biocompatible materials, including but not limited to biocompatible metals such as Titanium, Titanium alloys, stainless steel alloys, cobalt-chromium steel alloys, nickel-titanium alloys, shape memory alloys such as Nitinol, biocompatible ceramics, and biocompatible polymers such as Polyether ether ketone (PEEK) or a polylactide polymer (e.g. PLLA) and/or others. In some embodiments, the expansion mechanism  160  may be formed of different materials than the expandable intervertebral implant  100 . For example, the expansion mechanism  160  may be formed a material that is suitably strong enough to withstand torque applied to the driver  162  of the expansion mechanism  160  to activate the driver  162 . 
     In one embodiment, the expansion mechanism  160  includes a screw member  400 . The screw member  400  includes a shank  402 , a head  404 , a proximal end  406 , and a distal end  408 . 
     The shank  402  is a narrow structure that joins the head  404  with the distal end  408 . In one embodiment, the shank  402  includes threads  410 . The threads  410  are configured to engage with internal threads  154  of the opening  150 . The threads  410  may extend from the proximal end  406  to the distal end  408 . Alternatively, the threads  410  may extend from the distal end  408  part way along the shank  402 . In the illustrated embodiment, the shank  402  includes one or more slots  412 . The slots  412  may extend along a length of the shank  402  and may pass through the shank  402  from one side to the opposite side. The slots  412  may facilitate bone growth through the expandable intervertebral implant as part of a recovery process once the expandable intervertebral implant is installed in a patient. 
     In one embodiment, the head  404  serves as the driver  162  of the expansion mechanism  160 . The head  404  can be at the proximal end  406  of the screw member  400 . The head  404  can be used to rotate the screw member  400  about a longitudinal axis  414  of the screw member  400  to activate the expansion mechanism  160 . 
     The screw member  400 , in certain embodiments, may include a tapered end  416  at the distal end  408 . The tapered end  416  facilitates placement and alignment of the screw member  400  with an opening  150  of an expandable intervertebral implant of this disclosure. 
       FIG. 4B  illustrates a side elevation view of the screw member  400  of  FIG. 4A .  FIG. 4B  illustrates that the head  404  connects to a proximal end  406  and the tapered end  416  connects to a distal end  408 . In certain embodiments, the screw member  400  has a circular cross section. As described in more details below, a cross-section of the screw member  400  has a greater diameter than one or more of a height and a width of the opening  150 . The greater height causes the expandable intervertebral implant to expand as the screw member  400  enters the opening  150 . 
       FIG. 5A  is an exploded view of the expandable intervertebral implant  300  of  FIG. 3A  with the screw member  400  of  FIG. 4A . The expandable intervertebral implant  300  is in a collapsed configuration.  FIG. 5A  illustrates an expansion mechanism  160  embodied as a screw member  400  configured to engage internal threads  154  and seat within the opening  150  at the proximal end  170 . In certain embodiments, the internal threads  154  may be considered a part of the expansion mechanism  160 . Alternatively, or in addition, certain embodiments of the expansion mechanism  160  may not require internal threads  154 . 
       FIG. 5A  illustrates an embodiment of the screw member  400  with a head  404  that includes a drive recess  502  on one end of the head  404 . The drive recess  502  is configured to receive a drive member of an inserter tool (not shown) used to install the expandable intervertebral implant. The drive recess  502  can be configured to have any one of a variety of shapes including slotted, Torx, Torx plus, Philips, Quadrex, Pozidriv, square recess, tri-wing, spanner, or the like. The drive recess  502  can be centered on a longitudinal axis of the screw member  400  which aligns with the longitudinal axis  152  when the screw member  400  is inserted into the opening  150 . Of course, those of skill in the art recognize that the shape and configuration of the drive member and the drive recess  502  can be reversed and thus comprise an embodiment within the scope of the present disclosure. 
       FIG. 5B  is perspective view of the expandable intervertebral implant  300  of  FIG. 3A  in an expanded configuration with the screw member  400  of  FIG. 4A  within the expanded configuration  300 . 
     Referring now to  FIGS. 5A and 5B  together, operation of the expandable intervertebral implant  300  is described. During a surgical procedure, a surgeon may install the expandable intervertebral implant  300  through a cannula for a MIS procedure or using another instrument for an invasive procedure. As the expandable intervertebral implant  300  is inserted into the body of the patient, the expandable intervertebral implant  300  is in a collapsed configuration. Once in the desired position, the driver  162  of the expansion mechanism  160  may be activated to transition the expandable intervertebral implant  300  from a collapsed configuration to an expanded configuration. 
     In  FIG. 5A , the expandable intervertebral implant  300  is in a collapsed configuration.  FIG. 5A  illustrates how the screw member  400  can be inserted into the opening  150  to cause the expandable intervertebral implant to transition from a collapsed configuration to a partially expanded configuration or fully expanded configuration. The screw member  400  may be passed through a cannula or inserted into the opening  150  directly by a user. In one embodiment, a cross-section for the tapered end  416  is smaller than, or not larger than, a height and width of the opening  150 . 
       FIG. 5B  illustrates the expandable intervertebral implant  300  in an expanded configuration. As used herein, a “collapsed configuration” refers to an arrangement of an upper plate  110 , a lower plate  120 , a first lattice  130 , a second lattice  140 , an opening  150 , and an expansion mechanism  160  such that the apparatus or assembly has its smallest height. In certain embodiments, the expandable intervertebral implant  300  is configured such that the upper plate  110  engages the lower plate  112  such that the upper plate  110  is as close as possible to the lower plate  112  in the collapsed configuration. As used herein, an “expanded configuration” refers to an arrangement of an upper plate  110 , a lower plate  120 , a first lattice  130 , a second lattice  140 , an opening  150 , and an expansion mechanism  160  such that the apparatus or assembly has its greatest height and/or width. In certain embodiments, the expandable intervertebral implant  300  is configured such that the upper plate  110  moves as far away from the lower plate  120  as possible in the expanded configuration. 
       FIG. 5B  illustrates a three-dimensional axis  510 . The three-dimensional axis  510  includes a cephalad-caudal axis  520 , a medial-lateral axis  530 , and an anterior-posterior axis  540 . The three-dimensional axis  510  is used to identify how an expandable intervertebral implant transitions from a collapsed configuration to an expanded configuration, including a partially expanded configuration. 
     In one embodiment, insertion of the expansion mechanism  160  causes the expansion of one or more sides/walls of the expandable intervertebral implant. In another embodiment, the expansion mechanism  160  may be integrated with, connected, or coupled to the expandable intervertebral implant such that activation of the expansion mechanism  160  causes the expansion of the expandable intervertebral implant. Similarly, de-activation, disengagement, or removal of the expansion mechanism  160  can cause contraction of the expandable intervertebral implant, transition of the expandable intervertebral implant towards a collapsed configuration. In yet another embodiment, lattices or meshes of the expandable intervertebral implant can be configured such that the expandable intervertebral implant retains an expanded configuration or partial expanded configuration in response to de-activation, disengagement, or removal of the expansion mechanism  160 . 
     In certain embodiments, activation of the expansion mechanism  160  can include insertion of the expansion mechanism  160  into the opening  150 . In such an embodiment, the driver  162  may include a force pressing the expansion mechanism  160  into the opening  150 . In the illustrated embodiment, the expansion mechanism  160  is embodied as a screw member  400  and the driver  162  is the drive recess  502 . The expansion mechanism  160  may be activated by inserting the distal end  408  of the screw member  400  into the opening  150  and arranging the threads  410  such that they engage the internal threads  154  and then engaging the drive recess  502  and rotating the screw member  400  about its longitudinal axis  414  in a direction that causes the screw member  400  to move further into the opening  150 . Engagement of the drive recess  502  and rotating the screw member  400  about its longitudinal axis  414  is referred to herein as activation of the driver  162 , for this embodiment. As the screw member  400  moves further into the opening  150 , the opening  150  enlarges to accept the screw member  400 . 
     In one embodiment, an amount of expansion provided by the expansion mechanism  160 , such as the screw member  400 , may be determined, at least in part, by a cross-sectional diameter of the screw member  400 . The greater the cross-sectional diameter of the screw member  400 , the greater the amount of expansion. Furthermore, the direction(s) of expansion may depend on the embodiment of the expandable intervertebral implant used. 
     For example, if the expandable intervertebral implant is embodied as the expandable intervertebral implant  200  of  FIGS. 2A,2B  having a first lattice  130 , a second lattice  140 , a solid upper plate  110 , a solid lower plate  120 , insertion of the screw member  400  into the opening  150  deforms the first lattice  130  and the second lattice  140 . The first lattice  130  and the second lattice  140  deform because the cross-sectional diameter of the screw member  400  is greater than a height of the opening  150 . Insertion of the screw member  400  and deformation of the first lattice  130  and the second lattice  140  expands the upper plate  110  and the lower plate  120  away from each other along the cephalad-caudal axis  520 . This expansion may cause the upper plate  110  to engage a superior vertebral body (not shown) and the lower plate  120  to engage an inferior vertebral body (not shown). Activation of the driver  162  separates the upper plate  110  from the lower plate  120  by deforming the first lattice  130  and the second lattice  140 . 
     If the expandable intervertebral implant is embodied as the expandable intervertebral implant  300  of  FIGS. 3A-3D and 5A, 5B  having a first wall  350  with a first mesh  360 , a second wall  352  with a second mesh  362 , an upper plate  110  that includes an upper mesh  370 , and a lower plate  120  having lower mesh  380 , insertion of the screw member  400  into the opening  150  deforms the first mesh  360 , the second mesh  362 , the upper mesh  370 , and the lower mesh  380 . In such an embodiment, the screw member  400  can have a cross-sectional diameter that is greater than a height and/or a width of the opening  150 . The first mesh  360 , the second mesh  362 , the upper mesh  370 , and the lower mesh  380  deform, at least in part, because the cross-sectional diameter of the screw member  400  is greater than the height and/or the width of the opening  150 . 
     Insertion of the screw member  400  and activation of the driver  162  (head  404  and drive recess  502 ) expands the upper plate  110  and the lower plate  120  away from each other along the cephalad-caudal axis  520  by expanding the first mesh  360  and the second mesh  362  and moves the first wall  350  and the second wall  352  away from each other along a medial-lateral axis  530  by expanding the upper mesh  370  and the lower mesh  380 . This expansion may cause the upper plate  110  to engage a superior vertebral body (not shown) and the lower plate  120  to engage an inferior vertebral body (not shown) and the first wall  350  and the second wall  352  to separate to fill more space between the superior vertebral body and the inferior vertebral body. 
     In one embodiment, activation of the driver  162  can include rotating a screw member  400  about its longitudinal axis  414  moves the screw member  400  deeper into the opening  150  such that the driver  162  expands the first mesh  360 , the second mesh  362 , the upper mesh  370 , and the lower mesh  380 . 
     In one embodiment, the expandable intervertebral implant may be embodied similar to the expandable intervertebral implant  300  illustrated in  FIGS. 3A-3D and 5A, 5B . In such an embodiment, the expandable intervertebral implant can include a first lattice  130  that connected a first upper side  112  of the upper plate  110  to a first lower side  122  of the lower plate  120 . The expandable intervertebral implant can also include a second lattice  140  that connected a second upper side  114  of the upper plate  110  to a second lower side  124  of the lower plate  120 . The expandable intervertebral implant can also include an upper lattice  310  in the upper plate  110  and a lower lattice  320  in the lower plate  120 . The expandable intervertebral implant can include an opening  150  with internal threads  154  about a longitudinal axis  152  between the upper plate  110 , the lower plate  120 , the first lattice  130  and the second lattice  140 . 
     In such an embodiment, insertion of a screw member  400  into the opening  150  deforms the first lattice  130 , the second lattice  140 , the upper lattice  310 , and the lower lattice  320 . In such an embodiment, the screw member  400  can have a cross-sectional diameter that is greater than a height and/or a width of the opening  150 . The first lattice  130 , the second lattice  140 , the upper lattice  310 , and the lower lattice  320  deform, at least in part, because the cross-sectional diameter of the screw member  400  is greater than the height and/or the width of the opening  150 . 
     Insertion of the screw member  400  and activation of the driver  162  (head  404  and drive recess  502 ) separates the upper plate  110  from the lower plate  120  by deforming the first lattice  130  and the second lattice  140  and separates the first lattice  130  and the second lattice  140  by deforming the upper lattice  310  and the lower lattice  320 . In one particular embodiment, the driver  162  is configured to rotate the screw member  400  about the longitudinal axis  414  and such rotation moves the screw member  400  within the opening  150  and expands the expandable intervertebral implant along the cephalad-caudal axis  520  and the medial-lateral axis  530  to a target expanded configuration. This expansion can cause the upper plate  110  to engage a superior vertebral body (not shown) and the lower plate  120  to engage an inferior vertebral body (not shown) and the first lattice  130  and the second lattice  140  to separate to fill more space between the superior vertebral body and the inferior vertebral body. In such an embodiment, activation of the expansion mechanism  160  by the driver  162  expands the upper plate  110  and the lower plate  120  away from each other along the cephalad-caudal axis  520  and moves the first lattice  130  and the second lattice  140  away from each other along a medial-lateral axis  530  by deforming the first lattice  130 , the second lattice  140 , the upper lattice  310 , and the lower lattice  320 . 
       FIG. 5C  is a side elevation view of the expandable intervertebral implant  300  of  FIG. 3A  in an expanded configuration.  FIG. 5D  is a plan view of the expandable intervertebral implant  300  of  FIG. 3A  in an expanded configuration.  FIGS. 5C and 5D  illustrate one embodiment of an expandable intervertebral implant with the expansion mechanism  160  activated such that the expandable intervertebral implant is in an expanded configuration. 
     In the illustrated embodiment, the expansion mechanism  160  comprises a screw member  400  inserted within the opening  150 .  FIG. 5C  illustrates that the first lattice  130  is expanded, deformed, or stretched along the cephalad-caudal axis  520 . Similarly, the second lattice  140  (not shown in  FIG. 5C ) is expanded, deformed, or stretched along the cephalad-caudal axis  520 .  FIG. 5D  illustrates that the upper lattice  310  is expanded, deformed, or stretched along the medial-lateral axis  530 . Similarly, the lower lattice  320  (not shown in  FIG. 5D ) is expanded, deformed, or stretched along the medial-lateral axis  530 . 
       FIGS. 5C and 5D  illustrate that the expandable intervertebral implant  300  includes a proximal end  170  and a distal end  180 . In one embodiment, the expandable intervertebral implant  300  includes a first wall  350  having a first mesh  360  and a second wall  352  having a second mesh  362 .  FIG. 5C  illustrates that the first mesh  360  spans the first wall  350  from the first upper side  112  to the first lower side  122  and from the proximal end  170  to the distal end  180 . Because the first wall  350  is symmetrical to the second wall  352 , those of skill in the art will recognize that the second mesh  362  of the expandable intervertebral implant  300  spans the second wall  352  from the second upper side  114  to the second lower side  124  and from the proximal end  170  to the distal end  180 . 
     In one embodiment, the expandable intervertebral implant  300  includes an upper plate  110  having an upper mesh  370  and a lower plate  120  having a lower mesh  380 .  FIG. 5D  illustrates that the upper mesh  370  spans the upper plate  110  from the first upper side  112  to the second upper side  114  and from the proximal end  170  to the distal end  180 . Because the lower plate  120  is symmetrical to the upper plate  110 , those of skill in the art will recognize that the lower mesh  380  of the expandable intervertebral implant  300  spans the lower plate  120  from the first lower side  122  to the second lower side  124  and from the proximal end  170  to the distal end  180 . 
     In certain embodiments, the expandable intervertebral implant  300  includes an inserter attachment feature  550 . The inserter attachment feature  550  serves to connect the expandable intervertebral implant  300  to an insertion tool (not shown) during an operation. For example, the inserter attachment feature  550  may be configured to removably attach the expandable intervertebral implant  300  to part of an insertion tool.  FIGS. 5C and 5D  illustrate that the inserter attachment feature  550  may have a dove-tail shape ( FIG. 5D ) that enables a clamp, jaws, fork, or similar part of an insertion tool to removably engage with the expandable intervertebral implant  300  when the expandable intervertebral implant  300  is being positioned during an operation. Those of skill in the art will appreciate the different insertion tools that can removably engage the plurality of teeth  330  and provide a counter-torque when an expansion mechanism  160  is activated (such as rotation of a screw member  400 ). 
     Advantageously, as illustrated in  FIGS. 5C and 5D , a lattice, mesh, or other pattern of an upper plate  110 , lower plate  120 , first wall  350 , second wall  352 , first lattice  130 , or second lattice  140  may extend to include the structures of the inserter attachment feature  550 . In this manner, as the expandable intervertebral implant  300  expands along a cephalad-caudal axis  520  and/or medial-lateral axis  530 , components of the inserter attachment feature  550  do not impede the expansion. 
       FIG. 5E  illustrates a proximal end view of the expandable intervertebral implant  300  of  FIG. 5A  in a collapsed configuration and a proximal end  406  of a screw member  400 .  FIG. 5F  illustrates a distal end view of the expandable intervertebral implant  300  of  FIG. 5A  in a collapsed configuration and a distal end  408  of a screw member  400 . 
     Referring now to  FIGS. 5E and 5F , in one embodiment, the opening  150  includes a height H and a width W. The opening  150  may have an ovoid cross-section  552 . The ovoid cross-section  552  includes a height H that is different from a width W of the ovoid cross-section  552 . In one embodiment, the height H is shorter than the width W. Alternatively, or in another embodiment, the opening  150  may have an elliptical cross-section having a height H that is smaller than a width W. 
     The size and shape of the opening  150  and the cross-sectional diameter of the screw member  400  (including the threads  410 ) impact how much the expandable intervertebral implant  300  expands when the screw member  400  is inserted into the opening  150 . In one embodiment, the screw member  400  has a cross-sectional diameter D greater than height H of the opening  150 . In this manner, as the screw member  400  is inserted in the opening, the lattice, mesh, and/or pattern of pores/openings in the upper plate  110  (or upper mesh  370 ), lower plate  120  (or lower mesh  380 ), and first lattice  130  and second lattice  140  (or first wall  350  and second wall  352 ) enable the opening  150  to enlarge to accept the screw member  400 . In certain embodiments, the cross-sectional diameter D of the screw member  400  is greater than width W of the opening  150 . In such an embodiment, insertion of the screw member  400  causes the opening  150  to widen beyond width W. 
     A drive member is configured to engage the drive recess  502  and rotate the screw member  400  in direction  560  or in direction  570 . In one embodiment, rotation of the screw member  400  in direction  560  moves the screw member  400  deeper into the opening  150  and rotation of the screw member  400  in direction  570  moves the screw member  400  out of the opening  150 , extracts the screw member  400 . In one embodiment, activation of a driver  162  includes engaging the drive recess  502  and rotating the screw member  400  in the direction that moves the screw member  400  into the opening  150  and de-activation of the driver  162  includes engaging the drive recess  502  and rotating the screw member  400  in the direction that removes the screw member  400  from the opening  150 . 
       FIGS. 5E and 5F  illustrate the expandable intervertebral implant in a collapsed configuration with a height  580  and a width  590  which are the respective height and width of the expandable intervertebral implant  300  prior to activation of the driver  162  of the expansion mechanism  160 . 
       FIG. 5G  illustrates a proximal end view of the expandable intervertebral implant  300  of  FIG. 5A  in an expanded configuration with a screw member  400 .  FIG. 5H  illustrates a distal end view of the expandable intervertebral implant  300  of  FIG. 5A  in an expanded configuration with a screw member  400 . In the expanded configuration, the height  580  has become a greater height  580 ′ and the width  590  has become a greater width  590 ′.  FIGS. 5G and 5H  illustrate that the expandable intervertebral implant  300  has expanded along both the cephalad-caudal axis  520  and the medial-lateral axis  530  to a target expanded configuration. The target expanded configuration may have the increased height  580 ′ and increased width  590 ′. 
     In certain embodiments, the expandable intervertebral implant  300  can include a first mesh  360  (of first wall  350 ), a second mesh  362  (of second wall  352 ), an upper mesh  370  and a lower mesh  380 . The first mesh  360  and second mesh  362  may each have a particular pattern of pores or openings in the mesh, referred to herein as a first pattern. In addition, the opening  150  may comprise an elliptical cross-section with a predetermined height H. In such an embodiment, the first pattern and height of the elliptical cross-section of the opening  150  may be each selected such that activation of the driver  162  of the expansion mechanism  160  causes a predetermined increase in distance (ΔH=height  580 ′−height  580 ) between the upper plate  110  and the lower a plate  120 . 
     In addition, or alternatively, the upper mesh  370  and lower mesh  380  may each include a second pattern. The second pattern may be the same as the first pattern or the first pattern and the second pattern may each be different. The first pattern and the second pattern may each be selected such that activation of the driver  162  of the expansion mechanism  160  causes a first predetermined increase in a distance, such as (ΔH=height  580 ′−height  580 , or h 1 +h 2 ), between the upper plate  110  and the lower plate  120  that differs from a second predetermined increase in a distance, such as (ΔW=width  590 ′−width  590 , or w 1 +w 2 ), between the first wall  350  and the second wall  352 . By using a different pattern for the upper lattice  310  and lower lattice  320  from a pattern used for the first lattice  130  and second lattice  140  an amount of expansion along a cephalad-caudal axis  520  and a medial-lateral axis  530  can each be independently managed or determined. 
     In certain embodiments, a range of expandable intervertebral implants may be made available to a surgeon. The range of expandable intervertebral implants may include a plurality of variations among the size and/or shape of the opening  150 , pattern(s) for the lattice and/or mesh of the lattices, walls, or plates, different expansion mechanisms  160 , and the like. For example, different patterns for opposite sides of the expandable intervertebral implant may be used in the range of expandable intervertebral implants which each provide a different amount of expansion when installed. 
     If a range of implants may be used for a given procedure, the plurality of variations among the size and/or shape of the opening  150 , pattern(s) for the lattice and/or mesh of the lattices, walls, or plates, different expansion mechanisms  160  may facilitate pre-operative selection of the optimal implant(s). More particularly, a suitable size, shape, ratio of collapsed height and/or width to expanded height and/or width, type of expansion mechanism  160 , and/or other hardware may be pre-operatively selected. In this manner, the surgeon may choose an expandable intervertebral implant that may provide an optimal outcome for the patient. 
     In one embodiment, that includes a single pre-operatively selected expandable intervertebral implant or an expanded configuration selected from a range of implants, the first lattice  130  and the second lattice  140  may each have a pre-selected first pattern, size of the opening  150 , and/or cross-sectional diameter of the screw member  400  such that rotation of the screw member  400  about the longitudinal axis moves the screw member  400  within the opening  150  and expands the expandable intervertebral implant  100 / 300  along a cephalad-caudal axis  520  and along a medial-lateral axis  530  to a target expanded configuration. 
     Alternatively, or in addition, a single expandable intervertebral implant may be available and the expansion mechanism  160  may include a set of screw members  400 . Each member of the set of screw members  400  may have a different cross-sectional diameter. In one embodiment, a surgeon may use a plurality of screw member  400  from the set of screw members  400  to expand the expandable intervertebral implant. For example, the surgeon may start with a screw member  400  having a smaller diameter, insert this screw member  400 , remove the smaller diameter screw member  400 , and then insert progressively larger diameter screw members  400  until an optimal level of expansion is achieved. 
       FIGS. 6A-6F  illustrates different patterns that can be used in embodiments of the present disclosure.  FIG. 6A  illustrates a pattern  600  created by a uniform spacing of geometric shapes  602 . In certain embodiments, the pattern  600  may be formed from one or more other geometric shapes including polygons, and shapes formed from curves such as circles, ovals, ovoids, ellipse, or the like. In certain embodiments, the edges  604  are configured to break or fail as the expandable intervertebral implant expands. This breakage may increase structural strength of components of the expandable intervertebral implant that include these edges  604 . 
     In  FIG. 6A , the geometric shapes  602  are hexagons. The geometric shapes  602  are formed by edges  604  that define pores or openings  606  in the pattern  600 . The pores  606  facilitate expansion of the structure having the pattern. The pores  606  may facilitate bone growth through the expandable intervertebral implant as part of a recovery process once the expandable intervertebral implant is installed in a patient. 
     As an expandable intervertebral implant expands the geometric shapes  602  deform and stretch. The size, shape, and distribution of the pores  606  may be predetermined such that the structure having the pattern will expand to a desired or target distance. 
     In the pattern  600   a  of  FIG. 6A , the geometric shapes  602  are hexagons. In the pattern  600   b  of  FIG. 6B , the geometric shapes  602  are octagons. In the pattern  600   c  of  FIG. 6C , the geometric shapes  602  are diamonds. In the pattern  600   d  of  FIG. 6D , the geometric shapes  602  are ovals. In the pattern  600   e  of  FIG. 6E , the geometric shapes  602  are triangles. In the pattern  600   f  of  FIG. 6D , the geometric shapes  602  are quadrilaterals, such as for example trapezoids. 
       FIGS. 7A-6F  illustrates different patterns  700   a - c  that can be used in various embodiments of the present disclosure. In certain embodiments, the patterns  700   a - c  can include one geometric shape, two geometric shapes, or a combination three or more geometric shapes. The shapes and/or designs that make up the pattern are a set of geometric shapes. Each of the shapes of the pattern can include a pore or opening such that the pattern includes a distributed set of one or more geometric shapes comprising a set of pores. 
     For example, pattern  700   a  illustrates a pattern for embodiments in which the pattern includes two geometric shapes. In the illustrated embodiment, the pattern  700   a  includes a repeated and evenly distributed set of circles  702  and hexagons  704 . 
     Pattern  700   b  illustrates a pattern for embodiments in which the pattern includes three geometric shapes. In the illustrated embodiment, the pattern  700   a  includes a repeated and evenly distributed set of pentagons  706 , ovals  708 , and hexagons  710 . 
     Pattern  700   c  illustrates a pattern for embodiments in which the pattern includes three geometric shapes. In the illustrated embodiment, the pattern  700   a  includes a repeated and evenly distributed set of octagons  712 , diamonds  714 , and triangles  716 . 
     Referring generally to  FIGS. 6A-6F and 7A-7C , those of skill in the art recognize that the pattern used in the mesh or lattices of the present disclosure can be of any shape, design or pattern. The examples disclosed herein, are examples of a few of the possible patterns that can be used. In addition, the mesh and/or lattices that include a pattern can be made from the same material as other structures of the expandable intervertebral implant. For example, each of these structures can be made from titanium or a titanium alloy. For example, in one embodiment, the upper plate  110 , the lower plate  120 , the first lattice  130 , and the second lattice  140  can be made from titanium or a titanium alloy. 
     Alternatively, or in addition, meshes and/or lattices that include a pattern can be made from a different material as other structures of the expandable intervertebral implant. In certain embodiments, the pattern, the size of the pores in the pattern the positioning and distribution of geometric shapes or other designs that create the pattern and the thickness of edges  604  for the pattern can each be selected or designed to achieve a desired increase in distance between plates, walls, or lattices of an expandable intervertebral implant. 
     Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified. 
     Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment. 
     Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. 
     Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112 Para. 6. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles set forth herein. 
     While specific embodiments and applications of the present disclosure have been illustrated and described, it is to be understood that the scope of this disclosure is not limited to the precise configuration and components disclosed herein. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present disclosure set forth herein without departing from it spirit and scope.