Patent Description:
The use of fusion-promoting interbody implantable devices, often referred to as cages or spacers, is well known as the standard of care for the treatment of certain spinal disorders or diseases. For example, in one type of spinal disorder, the intervertebral disc has deteriorated or become damaged due to acute injury or trauma, disc disease or simply the natural aging process. A healthy intervertebral disc serves to stabilize the spine and distribute forces between vertebrae, as well as cushion the vertebral bodies. A weakened or damaged disc therefore results in an imbalance of forces and instability of the spine, resulting in discomfort and pain. A typical treatment may involve surgical removal of a portion or all of the diseased or damaged intervertebral disc in a process known as a partial or total discectomy, respectively. The discectomy is often followed by the insertion of a cage or spacer to stabilize this weakened or damaged spinal region. This cage or spacer serves to reduce or inhibit mobility in the treated area, in order to avoid further progression of the damage and/or to reduce or alleviate pain caused by the damage or injury. Moreover, these type of cages or spacers serve as mechanical or structural scaffolds to restore and maintain normal disc height, and in some cases, can also promote bony fusion between the adjacent vertebrae.

However, one of the current challenges of these types of procedures is the very limited working space afforded the surgeon to manipulate and insert the cage into the intervertebral area to be treated. Access to the intervertebral space requires navigation around retracted adjacent vessels and tissues such as the aorta, vena cava, dura and nerve roots, leaving a very narrow pathway for access. The opening to the intradiscal space itself is also relatively small. Hence, there are physical limitations on the actual size of the cage that can be inserted without significantly disrupting the surrounding tissue or the vertebral bodies themselves.

Further complicating the issue is the fact that the vertebral bodies are not positioned parallel to one another in a normal spine. There is a natural curvature to the spine due to the angular relationship of the vertebral bodies relative to one another. The ideal cage must be able to accommodate this angular relationship of the vertebral bodies, or else the cage will not sit properly when inside the intervertebral space. An improperly fitted cage would either become dislodged or migrate out of position, and lose effectiveness over time, or worse, further damage the already weakened area.

Thus, it is desirable to provide intervertebral cages or spacers that not only have the mechanical strength or structural integrity to restore disc height or vertebral alignment to the spinal segment to be treated, but also be configured to easily pass through the narrow access pathway into the intervertebral space, and then accommodate the angular constraints of this space, particularly for larger lordotic angles. <CIT> describes expandable spinal fusion devices that can be inserted in a subject in a collapsed state through a small surgical corridor, and then expand cephalocaudal only, transverse only, or in both directions. The direction of expansion can also be obtained independently, if desired, after the insertion. <CIT> describes an expandable implant for inserting within a skeletal space. The implant is designed to be inserted into an intervertebral space to replace at least part of an intervertebral disc between adjacent vertebral bodies. The expandable implant contains at least one first expansion compartment and at least one second expansion compartment. The compartments can be inflatable balloons that are inflated by a catheter. Inflating the first expansion compartment expands the implant in a first direction and inflating the second expansion compartment expands the implant in a second direction. <CIT> describes an intervertebral implant including a frame including an end member and an intermediate member pivotally coupled to the end member about a first pivot axis. The intervertebral implant includes a first vertebral contact member pivotally coupled to the frame about a second pivot axis that is substantially perpendicular to the first pivot axis, and a second vertebral contact member coupled to the frame. The frame is configured such that pivoting the intermediate member with respect to the end member about the first pivot axis changes both a width between the first vertebral contact member and the second vertebral contact member with respect to a direction that is substantially parallel to the second pivot axis, and changes a height between the first vertebral contact member and the second vertebral contact member with respect to a direction that is substantially parallel to the first pivot axis. <CIT> describes an expansible intervertebral implant comprising an elongated body along a longitudinal axis comprised between a proximal end and a distal end, a flexible arm mounted in the vicinity of the distal end of the longitudinal body and movable between: a folded-back position with the arm substantially parallel to the axis, and a deployed position with the arm not parallel to the axis and away from the body to expand said implant along an axis, by assuming the general shape of a circular arc, a means for deployment of said flexible arm for deploying the latter from the folded-back position to the deployed position, by the sliding of a proximal portion of said flexible arm with respect to the body inducing an increase in the space occupied by the implant, greater than the space of the implant in the folded-back position. <CIT> describes an expandable fusion device capable of being installed inside an intervertebral disc space to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion. The fusion device described herein is capable of being installed inside an intervertebral disc space at a minimum to no distraction height and for a fusion device capable of maintaining a normal distance between adjacent vertebral bodies when implanted.

According to a first aspect of the present invention, there is provided an intervertebral implant, as defined in claim <NUM>. Optional further features of the intervertebral implant are defined in the dependent claims. The intervertebral implant includes an implant body that defines a superior body configured to face a superior vertebra, and an inferior body configured to face an inferior vertebra. The implant further includes an actuator supported by the implant body, the actuator movable in the implant body from an initial position to a first expansion position, and subsequently from the first expansion position to a second expansion position. Movement of the actuator from the initial position to the first expansion position causes the actuator to urge the implant body to expand along a first direction of expansion, and movement of the actuator from the first expansion position to the second expansion position causes the actuator to urge the implant body to expand along a second direction of expansion that is perpendicular to the first direction of expansion.

The actuator is translatable from the initial position to the first expansion position. The actuator is further translatable from the first expansion position to the second expansion position.

The actuator may be translatable in a distal direction from the initial position to the first expansion position. The actuator may be further translatable in the distal direction from the first expansion position to the second expansion position.

The first direction of expansion is perpendicular to the distal direction. The second direction of expansion is perpendicular to the distal direction and the first direction.

The actuator defines a head that urges the implant body to expand along the first and second directions of expansion.

In some examples, movement of the actuator from the initial position to the first expansion position does not urge the implant body to expand along the second direction of expansion.

In some examples, movement of the actuator from the first expansion position to the second expansion position does not urge the implant body to expand along the first direction of expansion.

The first direction of expansion may cause each of the superior body and the inferior body to expand. The second direction of expansion may cause at least one of the superior and inferior bodies to move away from the other of the superior and inferior bodies.

In some examples of the intervertebral implant: <NUM>) the implant body may define opposed ramped inner side surfaces and ramped superior and inferior surfaces, and at least respective portions of the ramped inner superior and inferior surfaces may be spaced distally from the ramped inner side surfaces, <NUM>) the actuator may ride along the ramped inner side surfaces so as to urge the implant body to expand along the first direction of expansion, and <NUM>) the actuator may ride along the ramped inner superior and inferior surfaces so as to urge the implant body to expand along the second direction of expansion.

The ramped inner superior and inferior surfaces may be stepped.

The actuator comprises a shaft portion and an enlarged head that extends out from the shaft portion along both the first and second directions of expansion. The enlarged head urges the implant body to expand along the first and second directions of expansion.

Expansion of the implant body along the second direction of expansion may change a lordotic angle defined by an exterior superior surface of the superior body and an external inferior surface of the inferior body.

Expansion of the implant body along the second direction of expansion may increase the lordotic angle.

The implant body may comprise a frame that includes a base and each of the superior and inferior bodies that extends distally from the base.

The superior and inferior bodies may flex about the base as the implant body expands along the second direction of expansion.

In some examples of the intervertebral implant: <NUM>) the superior body may comprise a first superior body portion, a second superior body portion, and a superior expandable mesh that may couple the first superior body portion to the second superior body portion, and <NUM>) the inferior body portion may comprise a first inferior body portion, a second inferior body portion, and an inferior expandable mesh that may couple the first inferior body portion to the second inferior body portion.

Expansion of the implant body along the first direction of expansion may cause <NUM>) at least one of the first and second superior body portions to move away from the other of the first and second superior body portions, and <NUM>) at least one of the first and second inferior body portions to move away from the other of the first and second inferior body portions.

The superior mesh may expand as the at least one of the first and second superior body portions moves away from the other of the first and second superior body portions. The inferior mesh may expand as the at least one of the first and second inferior body portions moves away from the other of the first and second inferior body portions.

The intervertebral implant may further comprise an expandable first side mesh that couples the first superior body portion to the first inferior body portion. The intervertebral implant may further comprise an expandable second side mesh that couples the second superior body portion to the second inferior body portion. The first and second side meshes may expand as the implant body expands along the second direction.

The foregoing summary, as well as the following detailed description of illustrative embodiments of the present application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the locking structures of the present application, there is shown in the drawings illustrative embodiments. It should be understood, however, that the application is not limited to the precise arrangements and instrumentalities shown. In the drawings:.

The present disclosure provides various spinal or intervertebral implants, such as interbody fusion spacers, or cages, for insertion between adjacent vertebrae. The devices can be configured for use in either the cervical or lumbar region of the spine. In some embodiments, these devices are configured as PLIF cages, or posterior lumbar interbody fusion cages. These cages can restore and maintain intervertebral height of the spinal segment to be treated, and stabilize the spine by restoring sagittal balance and alignment. In some embodiments, the cages may contain an articulating mechanism to allow expansion and angular adjustment. This articulating mechanism allows upper and lower plate components to glide smoothly relative to one another.

As illustrated in <FIG>, one or more intervertebral implants <NUM> can be inserted into an intervertebral space <NUM> in a first, insertion configuration characterized by a first reduced size its insertion end to facilitate insertion through a narrow access passage. The one or more intervertebral implants <NUM> can be inserted in a PLIF approach into the intervertebral space. However, it is recognized that the one or more intervertebral implants <NUM> can be inserted along any suitable approach as desired. While a pair of intervertebral implants <NUM> are shown inserted into the intervertebral space, it is also appreciated that a single implant can be inserted into the intervertebral space having any suitable size and shape as desired. The intervertebral space <NUM> is defined by a superior vertebra <NUM> and an inferior vertebra <NUM> that are spaced from each other along a transverse direction T, which defines a cranial-caudal direction when the intervertebral implant <NUM> is disposed in the intervertebral space <NUM>. As described herein, structure, elements, devices, and method steps described in the plural applies with equal force and effect to the singular unless otherwise indicated. For instance, while a pair of intervertebral implants <NUM> are illustrated as implanted in the intervertebral space <NUM> in <FIG>, it is appreciated that a single intervertebral implant <NUM> can alternatively be implanted in the intervertebral space <NUM>. Conversely, as described herein, structure, elements, devices, and method steps (not claimed) described in the singular applies with equal force and effect to the plural unless otherwise indicated.

The intervertebral implants <NUM> may be inserted having the first reduced size as illustrated in <FIG>, and then expanded to a second, expanded configuration having an expanded size once implanted, as illustrated in <FIG>. The second expanded size is greater than the first reduced size in at least one direction. In some embodiments, the second expanded size is greater than the first reduced size along two perpendicular directions that are each perpendicular to the direction of insertion. In their second expanded configuration, the cages are able to maintain the proper disc height and stabilize the spine by restoring sagittal balance and alignment.

For instance, as illustrated in <FIG>, the second expanded configuration can include a first expansion in a lateral direction A that is oriented perpendicular to the transverse direction T. In particular, the intervertebral implant <NUM> can expand in a first direction of expansion to achieve the first expansion along the lateral direction A. Thus, the first direction of expansion can be along the lateral direction A. That is, the implant has a first width along the lateral direction A in the first reduced size, and a second width along the lateral direction A in the second expanded size that is greater than the first width.

Further, as illustrated in <FIG>, the second expanded configuration can include a second expansion in a transverse direction T. In particular, the intervertebral implant <NUM> can expand in a second direction of expansion to achieve the second expansion along the transverse direction T. Thus, the second direction of expansion can be along the transverse direction T.

As described in more detail below, the intervertebral implant <NUM> can expand only along the first direction of expansion without expanding in the second direction of expansion. Subsequently, the intervertebral implant can expand only along the second direction of expansion without expanding in the first direction of expansion. In some examples, the implant can simultaneously expand along both the first and second directions of expansion after expanding only along the first direction of expansion and prior to expanding only along the second direction of expansion. Further, in some examples the intervertebral implant <NUM> can be expandable in the second direction of expansion only after expansion in the first direction of expansion has been completed.

It is contemplated that, in some embodiments, the intervertebral implant <NUM> may also be designed to expand in either or both of the first and second directions of expansion in a freely selectable (or stepless) manner to reach its second expanded configuration. The intervertebral implant <NUM> can further be configured to be able to adjust the angle of lordosis, and can accommodate larger lordotic angles in its second expanded configuration. Further, the intervertebral implant <NUM> may promote fusion to further enhance spine stability by immobilizing the adjacent vertebral bodies.

Additionally, the intervertebral implant <NUM> may be manufactured using selective laser melting (SLM) techniques, a form of additive manufacturing. The intervertebral implant <NUM> may also be manufactured by other comparable techniques, such as for example, 3D printing, electron beam melting (EBM), layer deposition, and rapid manufacturing. With these production techniques, it is possible to create an all-in-one, multi-component device which may have interconnected and movable parts without further need for external fixation or attachment elements to keep the components together. Accordingly, the intervertebral implant <NUM> disclosed herein can be formed of multiple, interconnected parts that do not require additional external fixation elements to keep together.

The intervertebral implant <NUM> manufactured in this manner does not have connection seams in some examples, whereas devices traditionally manufactured would have joined seams to connect one component to another. These connection seams can often represent weakened areas of traditionally manufactured implantable devices, particularly when the bonds of these seams wear or break over time with repeated use or under stress. By manufacturing the present intervertebral implant <NUM> using additive manufacturing, connection seams are avoided entirely and therefore the problem is avoided.

In addition, by manufacturing the intervertebral implant <NUM> using an additive manufacturing process, all of the components of the intervertebral implant <NUM> (including both an implant body and an actuator that is configured to expand the implant body as described below) remain a complete construct during both the insertion process as well as the expansion process. That is, multiple components of the intervertebral implant <NUM> are provided together as a collective single unit so that the collective single unit is inserted into the patient, actuated to allow expansion, and then allowed to remain as a collective single unit in situ. In contrast to other implantable implants requiring insertion of external screws or wedges for expansion, in the present embodiments the actuator does not need to be inserted into the cage, nor removed from the cage, at any stage during the process in some examples. This is because the actuator is manufactured to be captured internal to the implant body, and while freely movable within the cage, are already contained within the implant body so that no additional insertion or removal of the actuator is necessary.

In some embodiments, the implantable implant <NUM> can be made with a portion of, or entirely of, an engineered cellular structure that includes a network of pores, microstructures and nanostructures to facilitate osteosynthesis. For example, the engineered cellular structure can comprise an interconnected network of pores and other micro and nano sized structures that take on a mesh-like appearance. These engineered cellular structures can be provided by etching or blasting to change the surface of the device on the nano level. One type of etching process may utilize, for example, HF acid treatment. In addition, these cages can also include internal imaging markers that allow the user to properly align the implantable implant <NUM> and generally facilitate insertion through visualization during navigation. The imaging marker shows up as a solid body amongst the mesh under x-ray, fluoroscopy or CT scan, for example.

Another benefit provided by the implantable implant <NUM> of the present disclosure is that they are able to be specifically customized to the patient's needs. Customization of the implantable implant <NUM> is relevant to providing a preferred modulus matching between the implant device and the various qualities and types of bone being treated, such as for example, cortical versus cancellous, apophyseal versus central, and sclerotic versus osteopenic bone, each of which has its own different compression to structural failure data. Likewise, similar data can also be generated for various implant designs, such as for example, porous versus solid, trabecular versus non-trabecular, etc. Such data may be cadaveric, or computer finite element generated. Clinical correlation with, for example, DEXA data can also allow implantable devices to be designed specifically for use with sclerotic, normal, or osteopenic bone. Thus, the ability to provide customized implantable devices such as the ones provided herein allow the matching of the Elastic Modulus of Complex Structures (EMOCS), which enable implantable devices to be engineered to minimize mismatch, mitigate subsidence and optimize healing, thereby providing better clinical outcomes.

Turning now to <FIG>, the intervertebral implant <NUM> includes an implant body <NUM> and an actuator <NUM> that is disposed in the implant body <NUM>. The actuator <NUM> is configured to drive the implant body <NUM>, and thus the intervertebral implant <NUM>, to expand from the first insertion configuration to the second expanded configuration. The implant body <NUM>, and thus the intervertebral implant <NUM>, defines a distal end <NUM> and a proximal end <NUM> opposite the distal end <NUM>. Thus, a distal direction is defined as a direction from the proximal end <NUM> toward the distal end <NUM>. Conversely, a proximal direction is defined as a direction from the distal end toward the proximal end <NUM>. The distal and proximal directions can be oriented along a longitudinal direction L. The longitudinal direction L can be perpendicular to each of the transverse direction T and the lateral direction A. The distal end <NUM> defines a leading end with respect to an insertion direction into the intervertebral space, and the proximal end <NUM> defines a trailing end with respect to the insertion direction into the intervertebral space.

Referring now in particular to <FIG>, the implant body <NUM> includes a superior body <NUM> and an inferior body <NUM> opposite the superior body <NUM> along the transverse direction T. The superior body <NUM> defines an exterior superior surface <NUM> that is configured to face and abut the superior vertebra <NUM>, and the inferior body <NUM> defines an exterior inferior surface <NUM> that is configured to face and abut the inferior vertebra <NUM>, respectively. In one example, the superior and inferior bodies <NUM> and <NUM> can define projections in the form of teeth, spikes, ridges, or the like, that are configured to grip the superior and inferior bodies <NUM> and <NUM> so as to limit or prevent migration of the intervertebral implant <NUM> in the intervertebral space.

The superior body <NUM> can be split into a first superior body portion 34a and a second superior body portion 34b. The first and second superior body portions 34a and 34b can be aligned with each other along the lateral direction A. Further, the first and second superior body portions 34a and 34b can be mirror images of each other. The implant body <NUM> can include an expandable superior mesh portion <NUM> that extends between the first superior body portion 34a and the second superior body portion 34b. For instance, the superior mesh portion <NUM> can extend from the first superior body portion 34a to the second superior body portion 34b. Thus, the superior mesh portion <NUM> couples the first superior body portion 34a to the second superior body portion 34b. The superior mesh portion <NUM> can extend to the distal end of the implant body <NUM>, or can terminate at a location spaced in the proximal direction from the distal end of the implant body <NUM>. The superior mesh portion <NUM> can be oriented along the lateral direction A. Therefore, as will be described in more detail below, the superior mesh portion <NUM> is expandable so as to permit one or both of the first and second superior body portions 34a and 34b to move away from the other of the first and second superior body portions 34a and 34b as the intervertebral implant <NUM> expands along the lateral direction A.

The implant body <NUM> can define a base <NUM> that is positioned such that the first and second superior body portions 34a and 34b extend in the distal direction from the base <NUM>. The base <NUM> can define the proximal end <NUM> of the implant body <NUM>, and can further define an aperture that is configured to receive an actuation tool that is configured to apply an actuation force to the actuator <NUM>. The base <NUM> can be configured as an annular body that extends continuously about the perimeter of the implant body <NUM>. Thus, in one example, the base <NUM> can lie in a plane that is oriented along the transverse direction T and the lateral direction A. When the intervertebral implant <NUM> is in the first insertion configuration, the first and second superior body portions 34a and 34b can extend parallel to each other. Further, the first and second superior body portions 34a and 34b can be spaced from each other by a first distance when the intervertebral implant <NUM> is in the first insertion configuration. Alternatively, the first and second superior body portions 34a and 34b can abut each other when the intervertebral implant <NUM> is in the first insertion configuration.

The inferior body <NUM> can be split into a first inferior body portion 36a and a second inferior body portion 36b. The first and second inferior body portions 36a and 36b can be aligned with each other along the lateral direction A. Further, the first and second inferior body portions 36a and 36b can be mirror images of each other. The first inferior body portion 36a can be aligned with the first superior body portion 34a along the transverse direction T. Similarly, the second inferior body portion 36b can be aligned with the second superior body portion 34b along the transverse direction T. The implant body <NUM> can include an expandable inferior mesh portion <NUM> that extends from the first inferior body portion 36a and the second inferior body portion 36b. For instance, the inferior mesh portion <NUM> can extend from the first inferior body portion 36a to the second inferior body portion 36b. Thus, the inferior mesh portion <NUM> couples the first superior body portion 34a to the second superior body portion 34b. The inferior mesh portion <NUM> can further extend in the distal direction from the base <NUM>. The inferior mesh portion <NUM> can extend to the distal end of the implant body <NUM>, or can terminate at a location spaced in the proximal direction from the distal end of the implant body <NUM>. The inferior mesh portion <NUM> can be oriented along the lateral direction A. Therefore, as will be described in more detail below, the inferior mesh portion <NUM> is expandable so as to permit one or both of the first and second inferior body portions 36a and 36b to move away from the other of the first and second superior body portions 36a and 36b as the intervertebral implant <NUM> expands along the lateral direction A.

The first and second inferior body portions 36a and 36b can extend in the distal direction from the base <NUM>. When the intervertebral implant <NUM> is in the first insertion configuration, the first and second inferior body portions 36a and 36b can extend parallel to each other. Further, the first and second inferior body portions 36a and 36b can be spaced from each other by a first distance when the intervertebral implant <NUM> is in the first insertion configuration. Alternatively, the first and second superior body portions 36a and 36b can abut each other when the intervertebral implant <NUM> is in the first insertion configuration.

The implant body <NUM> can further include an expandable first side mesh portion <NUM> that extends between the first superior body portion 34a to the first inferior body portion 36a. For instance, the first side mesh portion <NUM> can extend from the first superior body portion 34a to the first inferior body portion 36a. Thus, the first side mesh portion <NUM> couples the first superior body portion 34a to the first superior body portion 34a. The first side mesh portion <NUM> can further extend in the distal direction from the base <NUM>. The first side mesh portion <NUM> can extend to the distal end of the implant body <NUM>, or can terminate at a location spaced in the proximal direction from the distal end of the implant body <NUM>. The first side mesh portion <NUM> can be oriented generally in the transverse direction T. Therefore, as will be described in more detail below, the first side mesh portion <NUM> is expandable along the transverse direction T so as to permit one or both of the first superior body portion 34a and the first inferior body portion 36a to move away from the other of the first superior body portion 34a and the first inferior body portion 36a as the intervertebral implant <NUM> expands along the transverse direction T.

The implant body <NUM> can further include an expandable second side mesh portion <NUM> that extends between the second superior body portion 34b to the second inferior body portion 36b. For instance, the second side mesh portion <NUM> can extend from the second superior body portion 34b to the second inferior body portion 36b. Thus, the second side mesh portion <NUM> couples the second superior body portion 34b to the second superior body portion 34b. The second side mesh portion <NUM> can further extend in the distal direction from the base <NUM>. The second side mesh portion <NUM> can extend to the distal end of the implant body <NUM>, or can terminate at a location spaced in the proximal direction from the distal end of the implant body <NUM>. The second side mesh portion <NUM> can be oriented generally in the transverse direction T. Thus, as will be described in more detail below, the second side mesh portion <NUM> is expandable along the transverse direction so as to permit one or both of the second superior body portion 34b and the second inferior body portion 36b to move away from the other of the first superior body portion 34b and the first inferior body portion 36b as the intervertebral implant <NUM> expands along the transverse direction T.

In one example, the implant body <NUM> can be configured such that the base <NUM> in combination with the first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b define a frame <NUM>. The implant body <NUM> can thus include the frame <NUM> and the mesh portions <NUM>, <NUM>, <NUM>, and <NUM> that each can extend in the distal direction from the base <NUM>. The first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b can be configured as arms that extend out from the frame <NUM> in the distal direction. Further, the first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b can define respective corners of an outer perimeter of the implant body in a plane that is oriented along each of the transverse direction T and the lateral direction A.

As shown, the first and second superior body portions 34a and 34b can be L-shaped in a plane that is oriented along the transverse direction T and the lateral direction A. That is, the first and second superior body portions 34a and 34b can each have a first region that extends laterally so as to define the exterior superior surface <NUM>, and a second region that extends inferiorly toward the first and second inferior body portions 36a and 36b, respectively. Similarly, the first and second inferior body portions 36a and 36b can be L-shaped in the plane that is oriented along the transverse direction T and the lateral direction A. That is, the first and second inferior body portions 36a and 36b can each have a respective first region that extends laterally so as to define the exterior inferior surface <NUM>, and a second region that extends superiorly toward the first and second superior body portions 36a and 36b, respectively.

Thus, the superior mesh portion <NUM> can extend from the first region of the first superior body portion 34a to the first region of the second superior body portion 34b. The inferior mesh portion can extend from the first region of the first inferior body portion 36a to the first region of the second inferior body portion 36b. The first side mesh portion <NUM> can extend from the second region of the first superior body portion 34a to the second region of the first inferior body portion 36a. The second side mesh portion <NUM> can extend from the second region of the second superior body portion 36a to the second region of the second inferior body portion 36b. It is recognized that any one or more up to all of the mesh portions can be interrupted by one or more additional superior body portions, inferior body portions, or side body portions.

The second regions of the first superior body portion 34a and the first inferior body portion 36a can define respective first and second portions of a first side wall <NUM> of the implant body <NUM>. The second regions of the second superior body portion 34b and the second inferior body portion 36b can define respective first and second portions of a second side wall <NUM> of the implant body <NUM>. Thus, the first and second portions of the first and second side walls <NUM> and <NUM>, respectively are continuous with the first regions of the first and second superior body portions 34a and 34b, and the first and second inferior body portions 36a and 36b, respectively, along a respective plane that is oriented along the transverse direction T and the lateral direction A in one example. In other examples, the first and second portions of the first and second side walls <NUM> and <NUM>, respectively, can be spaced from the first and second superior body portions 34a and 34b, and the first and second inferior body portions 36a and 36b, respectively, along the respective plane that is oriented along the transverse direction T and the lateral direction A.

The first and second superior body portions 34a and 34b and the first and second inferior body portions 36a and 36b can extend in the distal direction from the base <NUM>. When the intervertebral implant <NUM> is in the first insertion configuration, the first and second inferior body portions 36a and 36b can extend parallel to each other. Further, the first and second inferior body portions 36a and 36b can be spaced from each other by a first distance when the intervertebral implant <NUM> is in the first insertion configuration. Alternatively, the first and second superior body portions 36a and 36b can abut each other when the intervertebral implant <NUM> is in the first insertion configuration. Similarly, the first superior body portion 34a and the first inferior body portion 36a can extend parallel to each other. Further, the first superior body portion 34a and the first inferior body portion 36a can be spaced from each other, for instance by the first distance, when the intervertebral implant <NUM> is in the first insertion configuration. Alternatively, the first superior body portion 34a and the first inferior body portion 36a can abut each other when the intervertebral implant <NUM> is in the first insertion configuration. Similarly still, the second superior body portion 34b and the second inferior body portion 36b can extend parallel to each other. Further, the second superior body portion 34b and the second inferior body portion 36b can be spaced from each other, for instance by the first distance, when the intervertebral implant <NUM> is in the first insertion configuration. Alternatively, the second superior body portion 34b and the second inferior body portion 36b can abut each other when the intervertebral implant <NUM> is in the first insertion configuration.

The distal end <NUM> of the implant body <NUM> can be tapered so as to facilitate insertion of the intervertebral implant <NUM> into the intervertebral space. That is, each of the first and second superior body portions 34a-34b and the first and second inferior body portions 36a and 36b can be tapered toward at least one or more up to all of the other of the first and second superior body portions 34a-34b and the first and second inferior body portions 36a and 36b at the distal end <NUM> of the implant body <NUM>.

Referring now to <FIG>, the implant body <NUM> is configured to support the actuator <NUM> in an actuation cavity <NUM> of the implant body <NUM>. In particular, the actuator <NUM> can be disposed in the actuation cavity <NUM> as-manufactured in an additive manufacturing process. Thus, the actuator <NUM> need not be separately inserted into the actuation cavity <NUM> in one example. Further, the actuator <NUM> can be dimensioned such that it is not able to be inserted into the actuation cavity. It should be appreciated, however, that the present disclosure is not limited to additively manufacturing the intervertebral implant <NUM> unless otherwise indicated.

The actuator <NUM> can include a shaft portion <NUM> and an enlarged head <NUM> that extends out from the shaft portion <NUM> along the transverse direction T and the lateral direction A. For instance, the enlarged head <NUM> can extend out from the shaft portion <NUM> along the transverse direction T both superiorly and inferiorly, and can further extend out from the shaft portion <NUM> in opposite lateral directions A. The enlarged head <NUM> defines first and second lateral expansion surfaces <NUM> and first and second transverse expansion surfaces <NUM>. The enlarged head <NUM> can extend out from a distal terminal end of the shaft portion <NUM>. The implant body <NUM> can guide the actuator <NUM> to translate along the longitudinal direction L in the actuation cavity upon application of an actuation force to the actuator <NUM> along the longitudinal direction L. For instance, the implant body <NUM> can include one or more guide arms <NUM> that are oriented along the longitudinal direction L and are received in a slot <NUM> of the actuator <NUM>, thereby guiding the actuator <NUM> to translate along the longitudinal direction L. As will be described in more detail below, the enlarged head <NUM> is configured to urge the implant body <NUM> to expand along the first and second directions of expansion. While the enlarged head <NUM> defines the lateral and transverse expansion surfaces <NUM> and <NUM> in one example, it should be appreciated that any portion of the actuator <NUM> can alternatively define the lateral and transverse expansion surfaces <NUM> and <NUM>, such as the shaft portion <NUM> of the actuator <NUM>.

The implant body <NUM> can define first and second inner side surfaces <NUM> and <NUM> that are spaced from each other along the lateral direction A. The inner side surfaces <NUM> and <NUM> can be ramped so as to extend along the lateral direction A as they extend along the longitudinal direction L. That is, each of the first and second inner side surfaces <NUM> and <NUM> can include respective first and second ramped inner side surfaces <NUM> and <NUM> at a lateral expansion region <NUM> of the implant body <NUM>. The first and second ramped side surfaces <NUM> and <NUM> each taper inward toward the other of the first and second inner side surfaces <NUM> and <NUM> as they extend in the distal direction. The first and second ramped side surfaces <NUM> can be mirror images of each other with respect to a midplane that is oriented along the longitudinal direction L and the transverse direction T. Thus, the first and second ramped side surfaces <NUM> and <NUM> can define equal and opposite slopes in one example. Further, the first and second ramped side surfaces <NUM> and <NUM> can be aligned with each other along the lateral direction A. Alternatively, the slopes of the first and second ramped side surfaces <NUM> and <NUM> can be different than each other. The first ramped side surface <NUM> can be defined by both the first superior body portion 34a and the first inferior body portion 36a. Similarly, the second ramped side surface <NUM> can be defined by both the second superior body portion 34b and the second inferior body portion 36b.

The implant body <NUM> can define an inner superior surface <NUM> and an inner inferior surface <NUM> that are spaced from each other along the transverse direction T. The inner superior surface <NUM> and the inner inferior surface <NUM> can be ramped along the transverse direction T as they extend along the longitudinal direction L at a transverse expansion region <NUM> of the implant body <NUM>. That is, the inner superior surface <NUM> defines a superior ramped surface <NUM>, and the inner inferior surface <NUM> defines an inferior ramped surface <NUM>. The ramped surfaces <NUM> and <NUM> each taper inward toward the other of the inner superior surface <NUM> and the inner inferior surface <NUM> as they extend in the distal direction. The superior ramped surface <NUM> and the inferior ramped surface <NUM> can define equal and opposite slopes in one example. Alternatively, the slopes of the superior and inferior ramped surfaces <NUM> and <NUM> can be different than each other.

One or both of the ramped surfaces <NUM> and <NUM> can be stepped. Thus, the ramped surfaces <NUM> and <NUM> can include ramped surface segments <NUM> and risers <NUM> disposed between adjacent ramped surface segments <NUM>. The risers <NUM> can have a slope greater than that of the ramped surface segments <NUM>. Further, each of the risers <NUM> the superior ramped surface <NUM> can have the same slope, and each of the risers <NUM> of the inferior ramped surface <NUM> can have the same slope. The risers <NUM> of the superior ramped surface <NUM> and of the inferior ramped surface <NUM> can have the same slope as each other. The risers <NUM> can have a length along the longitudinal direction L that is less than the length of the ramped surface segments <NUM> along the longitudinal direction L.

The ramped surfaces <NUM> and <NUM> can be mirror images of each other about a midplane that is oriented along the longitudinal direction L and the lateral direction T. Thus, each of the ramped surface segments <NUM> of the superior ramped surface <NUM> can have the same slope, and each of the ramped surface segments <NUM> of the inferior ramped surface <NUM> can have the same slope. Further, the ramped surface segments <NUM> of the superior ramped surface <NUM> and the ramped surface segments <NUM> of the inferior ramped surface <NUM> can have the same slope as each other. The ramped surfaces <NUM> and <NUM> can be aligned with each other along the transverse direction T, such that the ramped surface segments <NUM> of the ramped surfaces <NUM> and <NUM> can be aligned with each other along the transverse direction T, and the risers <NUM> of the ramped surfaces <NUM> and <NUM> can be aligned with each other along the transverse direction T.

With continuing reference to <FIG>, the actuator <NUM> can define at least one actuator ratchet tooth <NUM> such as a plurality of actuator ratchet teeth <NUM>. The actuator ratchet teeth <NUM> can be on one side of the actuator <NUM> or on opposed sides of the actuator <NUM>. In one example, the actuator <NUM> includes first and second rows of actuator ratchet teeth <NUM> that are oriented along the longitudinal direction. The first and second rows of actuator ratchet teeth <NUM> can be opposite each other along the transverse direction T. Alternatively, the first and second rows of actuator ratchet teeth <NUM> can be opposite each other along the lateral direction A. Alternatively still, the actuator ratchet teeth <NUM> can have a length that extends about the actuator <NUM> a distance sufficient to define first and second portions at locations of the actuator <NUM> that are opposite each other. The actuator ratchet teeth <NUM> can be disposed on the shaft portion <NUM> of the actuator <NUM>, but can be alternatively disposed as desired.

The implant body <NUM> can further define at least one implant ratchet tooth <NUM> that is configured to interlock with the at least one actuator ratchet tooth <NUM>. The ratchet teeth <NUM> and <NUM> are configured to interlock so as to resist movement of the actuator <NUM> both in an expansion direction that causes the implant body <NUM> to iterate from the first insertion configuration toward the second expanded configuration, and in a contraction direction that causes the implant body to iterate from the second expanded configuration toward the first insertion configuration. In one example, the implant body <NUM> can include first and second rows of at least one implant ratchet tooth <NUM>. The first and second rows of the at least one implant ratchet tooth can be aligned with the first and second rows of the at least one actuator tooth <NUM>. Thus, the first and second rows of at least one implant ratchet tooth can interlock with first and second rows of at least one actuator ratchet tooth <NUM>.

Further, the at least one actuator ratchet tooth <NUM> and the at least one implant ratchet tooth <NUM> can cam over each other as the actuator <NUM> is translated with respect to the implant body <NUM> along the longitudinal direction L. For instance, at least one or both of the at least one actuator ratchet tooth <NUM> and the at least one implant ratchet tooth <NUM> is displaceable away from the other of the at least one actuator ratchet tooth <NUM> and the at least one implant ratchet tooth <NUM>.

In one example, the implant body <NUM> includes at least one flexible arm <NUM> that carries the at least one implant ratchet tooth <NUM>. The at least one implant ratchet tooth <NUM> can be a single ratchet tooth <NUM> as illustrated, or a plurality of ratchet teeth <NUM>. For instance, the implant body <NUM> includes first and second flexible arms <NUM> that each carry at least one implant ratchet tooth <NUM>. Further, the at least one actuator tooth <NUM> is configured as a plurality of actuator teeth <NUM>. As the actuator <NUM> is translated along the distal direction and the proximal direction, selectively, the at least one implant ratchet tooth cams <NUM> over the actuator teeth <NUM> as the flexible arm <NUM> resiliently deflects away from the actuator teeth <NUM>. When the at least one implant ratchet tooth <NUM> is disposed between adjacent ones of the actuator teeth <NUM>, the teeth <NUM> and <NUM> define a mechanical interference with each other to prevent inadvertent movement of the actuator <NUM>. The mechanical interference can be overcome by application of an actuation force to the actuator <NUM> along the longitudinal direction. The actuator <NUM> can be guided to translate in the implant body <NUM> such that the actuator ratchet teeth <NUM> are aligned with the implant ratchet teeth <NUM> along the longitudinal direction L. That is, the implant body <NUM> can prevent the actuator <NUM> from rotating with respect to the implant body an amount that would bring the actuator teeth <NUM> out of longitudinal alignment with the implant ratchet teeth.

While each of the arms <NUM> carry a single implant ratchet tooth <NUM> and the actuator <NUM> carries a plurality of actuator ratchet teeth <NUM> in the illustrated example, other configurations are envisioned. For instance, each row of the implant body <NUM> can alternatively include a plurality of implant ratchet teeth <NUM> that are configured to intermesh with the at least one actuator ratchet tooth <NUM>. Further, each row of the actuator <NUM> can include a single actuator ratchet tooth <NUM> or a plurality of actuator ratchet teeth <NUM>. Further still, the actuator ratchet teeth <NUM> can be disposed on deflectable actuator arms if desired.

In still another example, referring to <FIG>, the actuator <NUM> can be rotatable about its central longitudinal axis. Thus, when the actuator is in a first rotational position, the actuator ratchet teeth <NUM> can be out of alignment with the implant ratchet teeth <NUM> with respect to the longitudinal direction L. Thus, the actuator <NUM> can be freely translatable in the implant body <NUM> along the longitudinal direction L without causing the actuator ratchet teeth <NUM> to mechanically interfere with the implant ratchet teeth <NUM>. Once the actuator <NUM> has been translated to a desired longitudinal position, the actuator <NUM> can be rotated to a second rotational position, whereby the at least one implant ratchet tooth <NUM> is disposed between adjacent ones of the actuator ratchet teeth <NUM>. In one example, the second rotational position can be ninety degrees offset from the first rotational position. Alternatively or additionally, the at least one actuator tooth <NUM> can be disposed between adjacent ones of a plurality of implant ratchet teeth <NUM>. When the actuator <NUM> is in the second rotational position, mechanical interference defined by the ratchet teeth <NUM> and <NUM> prevent movement of the actuator <NUM> relative to the implant body <NUM> along the longitudinal direction L.

Referring now to <FIG> in general, operation of the intervertebral implant <NUM> will now be described. In particular, the actuator <NUM> is movable in the implant body <NUM> from an initial position shown in <FIG> to a first expansion position shown in <FIG>, and subsequently from the first expansion position to a second expansion position, shown in <FIG>. Movement of the actuator <NUM> from the initial position to the first expansion position causes the actuator <NUM> to urge the implant body <NUM> to expand along a first direction of expansion from the first configuration shown in <FIG> to the first expansion shown in <FIG>. Movement of the actuator <NUM> from the first expansion position to the second expansion position causes the actuator <NUM> to urge the implant body <NUM> to expand along the second direction of expansion that is perpendicular to the first direction of expansion, as illustrated in <FIG>. In one example, the actuator <NUM> is translatable in the distal direction from the initial position to the first expansion position, and further from the first expansion position to the second expansion position. For instance, the actuator <NUM> can translate in the distal direction without undergoing rotation. Alternatively, in an alternative example the actuator <NUM> can be configured as a screw that rotates as it translates in the distal direction.

Referring now to <FIG> in particular, when the actuator <NUM> is in the initial position, the implant body <NUM> is in the first or initial configuration. When the implant body <NUM> is in the first or initial configuration, the implant body <NUM> defines a first width along the lateral direction A and a first height along the transverse direction T. Further, when the actuator <NUM> is in the initial position, the enlarged head <NUM> can be spaced from the ramped side surfaces <NUM> and <NUM> in the proximal direction. Alternatively, the enlarged head <NUM> can be aligned with the ramped side surfaces <NUM> and <NUM> along the lateral direction A. Accordingly, when the actuator <NUM> is in the initial position, the actuator has not yet urged the implant body to expand along the first direction of expansion, which can be defined by the lateral direction A.

As the actuator <NUM> is translated in the distal direction from the first or initial position to the first expansion position in the lateral expansion region <NUM>, the lateral expansion surfaces <NUM> ride along the first and second ramped side surfaces <NUM> and <NUM>, thereby expanding the implant body <NUM> along the lateral direction A from the initial configuration to a laterally expanded configuration, which can define the first expansion. The implant body <NUM> defines a first lateral distance between the proximal ends of the ramped side surfaces <NUM> and <NUM> along the lateral direction A, and a second lateral distance between the distal ends of the ramped side surfaces that is less than the first lateral distance. Therefore, as the lateral expansion surfaces <NUM> ride along the first and second ramped side surfaces <NUM> and <NUM>, the lateral expansion surface <NUM> urges the implant body <NUM> to expand along first direction of expansion to a second width along the lateral direction A that is greater than the first width. The first and second widths can be measured from the outer surface of the first side wall <NUM> to the outer surface of the second side wall <NUM>.

In particular, each of the superior body <NUM> and the inferior body <NUM> can expand along the lateral direction A. For instance, the actuator <NUM> urges at least one or both of the first superior body portion 34a and the second superior body portion 34b (see <FIG>) away from the other of the first superior body portion 34a and the second superior body portion 34b along the lateral direction A. Further, the actuator <NUM> urges at least one or both of the first inferior body portion 36a and the second inferior body portion 36b (see <FIG>) away from the other of the first inferior body portion 36a and the second inferior body portion 36b along the lateral direction A. Further still, the actuator <NUM> can urge either or both of the first side wall <NUM> and the second side wall <NUM> away from the other of the first side wall <NUM> and the second side wall <NUM>. The superior and inferior mesh portions <NUM> and <NUM> can expand along the lateral direction A as the implant body <NUM> expands along the lateral direction A.

While in one example the first and second inner side surfaces <NUM> and <NUM> are ramped, it should be appreciated that alternatively or additionally the lateral expansion surfaces <NUM> can be ramped. That is, the lateral expansion surfaces can be tapered toward each other along the lateral direction A as they extend in the distal direction. Thus, as the actuator <NUM> moves in the distal direction, the lateral expansion surfaces <NUM> can urge the implant body <NUM> to expand along the lateral direction A.

As described above, the first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b can each extend distally from the base <NUM>. Thus, as the implant body <NUM> expands along the first direction of expansion, the first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b can flex laterally outward with respect to the base <NUM>. Thus, the width of the implant body <NUM> along the lateral direction A at the proximal ends of the first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b can be less than the width of the implant body <NUM> along the lateral direction A at the distal ends of the first and second superior body portions 34a-34b and the first and second inferior body portions 36a-36b.

Referring now also to <FIG>, when the implant body <NUM> has expanded along the first direction of expansion, the actuator can be further translated along the distal direction from the first expansion position to the second expansion position, thereby expanding the implant to the second or expanded configuration. The second expansion position can be any position that causes the implant body <NUM> to expand along the second direction of expansion after expansion along the lateral direction A has completed. As will now be described, the second direction of expansion causes at least one or both of the superior and inferior bodies <NUM> and <NUM> to move away from the other of the superior and inferior bodies <NUM> and <NUM>.

When the actuator <NUM> is in the first expansion position, the implant body <NUM> has a first height along the transverse direction T. The implant body <NUM> also has the first height when the actuator <NUM> is in the initial position and the implant body <NUM> is in the first or initial configuration. Further, when the actuator <NUM> is in the first expansion position, the enlarged head <NUM> can be spaced from the superior ramped surface <NUM> and the inferior ramped surface <NUM> along the proximal direction. Alternatively, the enlarged head <NUM> can be aligned with the superior and inferior ramped surfaces <NUM> and <NUM> along the transverse direction T. When the actuator <NUM> is in the first expansion position, the actuator <NUM> has not yet urged the implant body <NUM> to expand along the second direction of expansion, which can be defined by the transverse direction T.

As the actuator <NUM> is translated in the distal direction from the first expansion position toward the second expansion position, the transverse expansion surfaces <NUM> ride along the superior ramped surface <NUM> and the inferior ramped surface <NUM>, thereby urging the implant body <NUM> to expand along the transverse direction T. The implant body <NUM> defines a first distance between the proximal ends of the superior and inferior ramped surfaces <NUM> and <NUM> along the transverse direction T, and a second transverse distance between the distal ends of the superior and inferior ramped surfaces <NUM> and <NUM> that is less than the first transverse distance. Therefore, as the transverse expansion surfaces <NUM> ride along the superior and inferior ramped surfaces <NUM> and <NUM>, the transverse expansion surfaces <NUM> urge the implant body <NUM> to expand along the transverse direction A to a second height along the transverse direction T that is greater than the first height. In particular, the actuator <NUM> urges at least one or both of the superior body <NUM> and the inferior body <NUM> (see <FIG>) away from the other of the superior body <NUM> and the inferior body <NUM> along the transverse direction T. The first and second side mesh portions <NUM> and <NUM> can expand along the transverse direction as the implant body <NUM> expands along the transverse direction T. The mesh portions <NUM>, <NUM>, <NUM>, and <NUM> can be constructed in accordance with any suitable embodiment as desired. In one example, the mesh portions can include a plurality of interconnected links that are movable with respect to each other so as to allow the mesh portions to expand along the respective directions.

As illustrated in <FIG>, when the implant <NUM> has been fully expanded along the second direction of expansion, the superior ramped surface <NUM> and the inferior ramped surface <NUM> can transition from the slopes described above to a second orientation that is less angled with respect to the longitudinal direction L. For instance, at least one or more of the superior and inferior ramped surfaces <NUM> and <NUM> can be oriented substantially along the longitudinal direction L, such as within +/- five degrees of the longitudinal direction L.

As described above, the superior and inferior bodies <NUM> and <NUM> can each extend distally from the base <NUM>. Thus, as the implant body <NUM> expands along the second direction of expansion, the superior and inferior bodies <NUM> and <NUM> can flex outward with respect to the base <NUM> along the transverse direction T. Thus, the height of the implant body <NUM> along the transverse direction T at the proximal ends of the superior and inferior bodies <NUM> and <NUM> can be less than the height of the implant body <NUM> along the transverse direction T at the distal ends of the superior and inferior bodies <NUM> and <NUM>. As a result, expansion of the implant body <NUM> along the second direction of expansion can change, for instance increase, a lordotic angle defined by the exterior superior surface <NUM> and the exterior inferior surface <NUM>. Further expansion of the implant body <NUM> along the second direction of expansion can further change the lordotic angle.

As described above, the ramped surfaces <NUM> and <NUM> can include ramped surface segments <NUM> and risers <NUM> disposed between adjacent ramped surface segments <NUM>. Thus, as the actuator <NUM> translates distally the transverse expansion surfaces <NUM> alternatingly ride along the ramped surface segments <NUM> and risers <NUM>. The implant body <NUM> can achieve a fully expanded height when the actuator <NUM> has translated to a position whereby the actuator <NUM> can no longer be translated along the distal direction. Further as described above, the implant body <NUM> and the actuator <NUM> include respective ratchet teeth <NUM> and <NUM> that are configured to engage each other so as to lock the implant body <NUM> in the second or expanded position. When the ratchet teeth <NUM> and <NUM> engage each other, the actuator <NUM> can be prevented from translating in the proximal direction with respect to the implant body <NUM>. In particular, at least one of the proximal surface of the implant ratchet teeth <NUM> and the distal surface of the actuator ratchet teeth <NUM> can be oriented to prevent the ratchet teeth <NUM> and <NUM> from camming over each other in the proximal direction. Thus, the actuator <NUM> can be prevented from translating in the proximal direction with respect to the implant body <NUM>.

As a result, the actuator <NUM> can be translated in the distal direction to a position whereby the transverse expansion surfaces <NUM> are engaged with the respective ramped surfaces <NUM> and <NUM>. The engagement of the ratchet teeth <NUM> and <NUM> can prevent the actuator <NUM> from translating in the proximal direction, which would cause the implant to collapse along the transverse direction T. Thus, the implant can be expanded to a position to a height along the transverse direction T that is less than the fully expanded height. Further, the ratchet teeth <NUM> and <NUM> can engage when the actuator <NUM> is in the first expansion position. Thus, the implant <NUM> can be locked in the laterally expanded configuration so as to prevent contraction of the implant <NUM> along the lateral direction A without expanding along the transverse direction T. Further, the implant <NUM> can be locked in the laterally expanded configuration and in a transverse expanded configuration having an expanded height less than the fully expanded height. Accordingly, expansion of the implant <NUM> along the transverse direction T can be controlled after the implant <NUM> has been fully expanded along the lateral direction A.

The first and second inner side surfaces <NUM> and <NUM> at the transverse expansion region <NUM> can be oriented along respective planes that are defined by the transverse direction T and the longitudinal direction L when the implant <NUM> has achieved the first expansion. Thus, as the lateral expansion surfaces <NUM> ride along the first and second inner side surfaces <NUM> and <NUM> as the actuator translates in the distal translation of the actuator <NUM> in the transverse expansion region <NUM>, the lateral expansion surfaces <NUM> do not urge the implant body <NUM> to expand along the lateral direction A. Accordingly, distal translation of the actuator head <NUM> in the transverse expansion region <NUM> causes the implant to expand along the transverse direction T without expanding along the lateral direction A. Alternatively, the first and second inner side surfaces <NUM> and <NUM> can be sloped inwardly toward each other along the lateral direction A as they extend in the distal direction. Thus, distal translation of the actuator <NUM> in the transverse expansion region <NUM> can cause the lateral expansion surfaces <NUM> of the actuator <NUM> urge the implant body <NUM> to further expand along the lateral direction A. In one example, the slope of the first and second inner side surfaces <NUM> and <NUM> can be less than the slope of the ramped inner side surfaces <NUM> and <NUM>.

While in one example the superior and inferior surfaces <NUM> and <NUM>, respectively, are ramped, it should be appreciated that alternatively or additionally the transverse expansion surfaces <NUM> can be ramped. That is, transverse expansion surfaces <NUM> can be tapered toward each other along the transverse direction T as they extend in the distal direction. Thus, as the actuator <NUM> moves in the distal direction, the transverse expansion surfaces <NUM> can urge the implant body <NUM> to expand along the lateral direction T.

As described above, at least a portion up to an entirety of the transverse expansion region <NUM> can be disposed distal of the lateral expansion region <NUM>. Thus, at least respective portions up to respective entireties of the superior and inferior ramped surfaces <NUM> and <NUM> can be disposed distal of the ramped side surfaces <NUM> and <NUM>. Accordingly, in one example, movement of the actuator <NUM> from the initial position to the first expansion position does not urge the implant body <NUM> to expand along the second direction of expansion. Alternatively, a portion of the vertical expansion region <NUM> can partially overlap the lateral expansion region <NUM>. Accordingly, the implant body <NUM> can further expand along the lateral direction A as it expands along the transverse direction T. In both examples, at least a portion of the vertical expansion region <NUM> extends distal of the lateral expansion region <NUM>, and the implant is expandable along the transverse direction T without expanding along the lateral direction A.

As described above, the first direction of expansion can be along the lateral direction A, and the second direction of expansion can be along the transverse direction T. Alternatively, the first direction of expansion can be along the transverse direction T, and the second direction of expansion can be along the lateral direction A. In this regard, at least a portion of the lateral expansion region <NUM> can be disposed distal of the transverse expansion region <NUM>.

Claim 1:
An intervertebral implant (<NUM>) comprising:
an implant body (<NUM>) defining a superior body (<NUM>) configured to face a superior vertebra and an inferior body (<NUM>) configured to face an inferior vertebra; and
an actuator (<NUM>) supported by the implant body (<NUM>), the actuator (<NUM>) movable in the implant body (<NUM>) from an initial position to a first expansion position, and subsequently from the first expansion position to a second expansion position,
wherein the actuator (<NUM>) defines a head (<NUM>) and movement of the actuator (<NUM>) from the initial position to the first expansion position causes the actuator head (<NUM>) to urge the implant body (<NUM>) to expand along a first direction of expansion, and movement of the actuator (<NUM>) from the first expansion position to the second expansion position causes the actuator head (<NUM>) to urge the implant body (<NUM>) to expand along a second direction of expansion that is perpendicular to the first direction of expansion.