Patent Description:
A common procedure for handling pain associated with intervertebral discs that have become degenerated due to various factors such as trauma or aging is the use of intervertebral spacers to, e.g., fuse one or more adjacent vertebral bodies. Generally, to fuse adjacent vertebral bodies, the native intervertebral disc is first partially or fully removed. An intervertebral spacer is then typically inserted between neighboring vertebral bodies to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion.

There are a number of known conventional intervertebral spacers and methodologies in the art for accomplishing the vertebral fusion. These include screw and rod arrangements, solid bone implants, and intervertebral spacers which include a cage or other implant mechanism that may be packed with bone and/or bone growth inducing substances. These devices may be implanted between adjacent vertebral bodies in order to fuse the vertebral bodies together, potentially alleviating any associated pain.

However, there are drawbacks associated with the known conventional vertebral spacers and methodologies. Some conventional vertebral spacers may not be optimally configured for insertion into irregular or curved portions of the spine. For example, at the most caudal or most cephalad cervical disc spaces or caudal lumbar levels, conventional, angled instruments used to install conventional fasteners may interfere with the chin, chest, or other portion of a patient's anatomy, making insertion of conventional fastening members difficult.

<CIT> discloses a system according to the known art.

According to the invention it is provided a system for inserting a vertebral having the features of the preamble of claim <NUM>. Further advantageous aspects of the invention are set forth in the dependent claims. According to a further aspect of the invention it is provided a system for inserting a vertebral anchor into a patient, the system comprising: a trailing housing defining a first elongate channel and a second elongate channel; an anchor housing defining a first anchor channel and a second anchor channel, the first anchor channel being aligned with the first elongate channel such that a guide member may extend through the first elongate channel and first anchor channel along a first longitudinal axis, the second elongate channel being aligned with the second anchor channel such that a guide member may extend through the second elongate channel and second anchor channel along a second longitudinal axis, wherein the first and second longitudinal axes are parallel to one another; and the first anchor channel is configured to urge a first vertebral anchor into a first vertebral body defining an intervertebral space and the second anchor channel is configured to urge a second vertebral anchor into a second vertebral body defining the intervertebral space. The system may include a third elongate channel and a third anchor channel, the third anchor channel being aligned with the third elongate channel such that a guide member may extend through the third elongate channel and third anchor channel along a third longitudinal axis that is parallel to the first and second longitudinal axes, wherein the third anchor channel is configured to urge a third vertebral anchor into the first vertebral body. it is described but does not form part of the invention a method of implanting an intervertebral spacer, the method comprising: positioning the intervertebral spacer coupled to a plate into an intervertebral space defined between a first vertebral body and a second vertebral body, wherein the intervertebral spacer comprises a plurality of bores, each of the plurality of bores being configured to receive either a linear fastening element or a curvilinear fastening element; aligning a leading end of a first guide member with a first vertebral anchor; applying a force to the first guide member along a first longitudinal axis to impact the first vertebral anchor through the plate and into the first vertebral body along a trajectory that intersects the first longitudinal axis. In a version the method further includes aligning the first guide member or a second guide member with a second vertebral anchor and applying a force to the first or second guide members along a second longitudinal axis to impact the second vertebral anchor through the plate and into the second vertebral body along a second trajectory that intersects the second longitudinal axis. Advantageously the method further includes aligning the first guide member or a third guide member with a third vertebral anchor and applying a force to the first or third guide members along a third longitudinal axis to impact the third vertebral anchor through the plate and into the first vertebral body along a third trajectory that intersects the third longitudinal axis. In a version, the first and third trajectories could be substantially parallel to one another. In another version the first, second, and third longitudinal axes are parallel to one another.

The present disclosure relates to examples of intervertebral spacers. A method of implanting an intervertebral spacer which is not part of the invention may include positioning the intervertebral spacer within an intervertebral space defined by adjacent vertebral bodies. The intervertebral spacer may include a plurality of bores, and each of the plurality of bores may be configured to receive either a linear fastening element or a curvilinear fastening element.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed examples.

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

<FIG> illustrate the different views of an intervertebral spacer <NUM> according to the present disclosure. The intervertebral spacer <NUM> as shown in <FIG> may be, e.g., a stand-alone anterior lumbar interbody spacer used to provide structural stability in skeletally mature individuals following discectomies. These intervertebral spacers may be available in various heights and geometric configurations to fit the anatomically needs of a wide variety of patients. Specifically, <FIG> illustrate one embodiment of an intervertebral spacer <NUM>. Intervertebral spacer <NUM> may be generally positioned in the intervertebral space between two adjacent vertebral bodies. As shown in the figures, intervertebral spacer <NUM> may include a spacer portion <NUM> and a plate portion <NUM>. In one example, the spacer portion <NUM> may include a graft window <NUM> for the placement of, e.g., bone graft or bone-growth inducing material, to enhance fusion between two adjacent vertebral bodies.

The spacer portion <NUM> can be comprised of any material that is conducive to the enhancement of fusion between the two adjacent vertebral bodies. In one particular embodiment, the spacer portion <NUM> is made of PEEK material, which may be physiologically compatible. It should be noted that any other materials that are physiologically compatible also may be used. The spacer portion <NUM> may include tantalum pins that enable radiographic visualization, or other suitable radiographic markers. The spacer portion <NUM> further may include superior and inferior surfaces that are provided with a plurality of geometric configurations, such as, e.g., protrusions <NUM> (e.g., ribs, bumps, other textures, or the like). The superior and inferior surfaces of the spacer portion <NUM> may be bi-convex for greater contact with the vertebral endplates of the adjacent vertebral bodies. The protrusions <NUM> can be configured to be any size or shape for further anchoring the spacer portion <NUM> to each of the adjacent vertebral bodies. Protrusions <NUM> on the superior and inferior surfaces of each implant may grip the endplates of the adjacent vertebral bodies to aid in expulsion resistance.

The plate portion <NUM> can also be comprised of any physiologically compatible material. In one example, the plate portion <NUM> of the intervertebral spacer <NUM> may be formed from titanium. The plate portion <NUM> may include at least one bore <NUM>. In some embodiments, plate portion <NUM> may include a plurality of bores <NUM>, in such embodiments, one or more bores <NUM> may or may not include threads for receiving corresponding threads on a fastener. That is to say, in some examples, one or more of bores <NUM> may interact with features (e.g., threads) configured to receive features (e.g., corresponding threads) of a fastening member (e.g., a linear bone screw) to be disposed therethrough. Bores <NUM> may be substantially linear. Such a configuration allows bores <NUM> to receive both linear fastening members and curvilinear fastening members. That is, a given bore <NUM> may be configured to receive either a linear fastening member (e.g., a screw) or a curvilinear fastening member (as discussed below in greater detail) at the discretion of an operator, surgeon, physician, or the like. In one embodiment, e.g., bores <NUM> may include one or more features, e.g., threads, that are configured to engage with threads of a fastening member (e.g., a linear fastening member or bone screw). Further, in some examples, a curvilinear fastening member disposed through a given bore <NUM> may be configured so as not to engage the threads of the given bore <NUM>. Still further, each bore <NUM> may include locking features configured to engage with complimentary features on a curvilinear fastening member to prevent the curvilinear fastening member from rotating when disposed through the bore <NUM>. In one example, each bore <NUM> may be defined by a circumferential wall having a recess (not shown) disposed therein. The recess may be configured to receive a protrusion extending from the curvilinear fastening member to prevent the curvilinear fastening member from rotating. In one example, three bores <NUM> may be provided. In yet another example, two outer bores <NUM> may surround a central bore <NUM>. The two outer bores <NUM> may be angled to guide a fastening member (e.g., a vertebral anchor <NUM> described with reference to <FIG>, or a bone screw) along a first trajectory <NUM> shown in <FIG> (e.g., toward one of a superior or inferior surface of intervertebral spacer <NUM>), while the central bore <NUM> may be angled to guide a fastening member along a second trajectory <NUM> (e.g., toward the other of the superior and inferior surface of intervertebral spacer <NUM>), and vice versa. In some examples, all bores <NUM> may guide respective fasteners along the same trajectory. The bores <NUM> can accommodate a straight longitudinal fastening member (e.g., a screw, pin, or the like) and/or a fastening member exhibiting a curvature (e.g., vertebral anchor <NUM> shown in <FIG>). In some examples, a combination of vertebral anchors <NUM> and conventional screws may be used to install the same intervertebral spacer <NUM>.

Also, in the plate portion <NUM> of the intervertebral spacer <NUM>, a fastener back out prevention mechanism may be provided. The fastener back out prevention mechanism may include one or more screws <NUM>, each having a head portion <NUM> and a shank <NUM> having threads 22a. Shank <NUM> may be received by a bore <NUM> (shown in <FIG>) that extends from a first side <NUM> of plate portion <NUM> toward a second side <NUM> of plate portion <NUM>. Shank <NUM> also may be received by a nut <NUM> having a threaded bore 18a (shown in <FIG>). Nut <NUM> may have a substantially rectangular cross-section, or may have another suitable shape. Nut <NUM> may be secured within a recess <NUM> on second side <NUM> of plate portion <NUM>. However, it is contemplated that screws <NUM> may be secured to plate portion <NUM> by any other suitable mechanism. Head portion <NUM> may have a generally rectangular cross-section such that it may prevent a fastening member from backing out of bores <NUM> when disposed in certain configurations (e.g., a blocking configuration). For example, referring to <FIG>, the head portion <NUM> of screw <NUM> may extend over, cover, and/or block at least a portion of the opening of one more of bores <NUM>, preventing a fastening member (e.g., a vertebral anchor <NUM> or a bone screw) extended through a bore <NUM> from backing out of plate portion <NUM> and a vertebral body. It is also contemplated that in some examples, a single head portion <NUM> may extend at least partially over two adjacent bores <NUM> (e.g., both an outer bore <NUM> and a central bore <NUM>), thereby blocking the openings of more than one bore <NUM> at the same time while disposed in a blocking configuration. Head portion <NUM> can be moved from the blocking configuration to a non-blocking configuration by rotating head portion by, e.g., <NUM> degrees or another suitable measure. While depicted as rectangular, it is contemplated that head portion <NUM> may be formed in other suitable elongate shapes, such as, e.g., cylindrical or the like. In the example of <FIG>, plate portion <NUM> may be configured to receive two screws <NUM> in bores <NUM> (shown in <FIG>). Each of the screws <NUM> may be configured to block fastening members disposed in an outer bore <NUM> and a central bore <NUM>, such that each outer bore <NUM> is blocked by a single screw <NUM>, and the central bore <NUM> is blocked by both screws <NUM>.

A coupling mechanism may connect the spacer portion <NUM> and the plate portion <NUM> rigidly to each other, if desired. With reference to <FIG>, the coupling mechanism may include one or more fastening members <NUM> that extend through corresponding recesses <NUM> disposed through spacer portion <NUM> and recesses <NUM> disposed through at least a portion of plate portion <NUM>. In one example, a fastening member <NUM> may extend through the superior and inferior surfaces of spacer portion <NUM> (via a recess <NUM>) and may be received by recess <NUM> of plate portion <NUM>, thereby coupling spacer portion <NUM> and plate portion <NUM>. It is contemplated that recess <NUM> and fastening member <NUM> may include complimentary mating features (e.g., threads) to facilitate coupling of plate portion <NUM> to spacer portion <NUM>. In the example shown in <FIG>, plate portion <NUM> may be formed by three bore sections <NUM>, <NUM>, and <NUM>. Bore sections <NUM>, <NUM>, and <NUM> may either be integrally formed or detachable with spacer portion <NUM>. In one example, bore section <NUM> may be integral with spacer portion <NUM> while bore sections <NUM> and <NUM> may be detachable with spacer portion <NUM> via fastening members <NUM> and recesses <NUM> and <NUM>. In one example, the detachable bore sections <NUM> and <NUM> may include the outer bores <NUM> that are configured to direct a vertebral anchor <NUM> or bone screw along the first exit trajectory <NUM>, and the bore section <NUM> may include the central bore <NUM> configured to direct a vertebral anchor <NUM> or bone screw along the second exit trajectory <NUM>. Further, one or more of the bore sections <NUM>, <NUM>, and <NUM> may include a portion configured to extend through a slot of or other opening in spacer portion <NUM>. In such examples, the recesses <NUM>, <NUM>, or the like associated with the bore sections may align with recesses formed through spacer portion <NUM> to receive fastening members <NUM>.

Plate portion <NUM> also may include coupling features for coupling plate portion <NUM> to an anchor insertion device <NUM> which will be described further with reference to <FIG>. As shown in <FIG>, plate portion <NUM> may include a channel (e.g., a snap-fit channel) <NUM> having an opening disposed in an outer surface of plate portion <NUM>. The channel <NUM> may be configured to receive an extension (e.g., a cantilever and/or snap-fitting extension) of anchor insertion device <NUM> to couple plate portion <NUM> to the insertion device <NUM>. In some examples, channel <NUM> may be disposed in bore section <NUM> of plate portion <NUM>. With continuing reference to <FIG>, channel <NUM> may have a generally ovular opening, although other suitable opening configurations such as, e.g., circular, square, rectangular, star-shaped, or the like are also contemplated. Plate portion <NUM> also may include a bore <NUM> (e.g., a threaded bore) having an opening that is also disposed through an outer surface of plate portion <NUM>. In one example, bore <NUM> may be disposed through bore section <NUM> of plate portion <NUM>.

In an exemplary method, not part of the invention, a physician, surgeon, or other suitable operator may remove, among other things, the native intervertebral disc between two vertebral bodies. The operator then may select a given intervertebral spacer, e.g., intervertebral spacer <NUM>, to replace the removed native intervertebral disc. Based on the geometry of the surrounding vertebral bodies and/or anatomy, the operator may determine that linear fastening members (e.g., linear bone screws), curvilinear fastening members (e.g., vertebral anchors <NUM> or <NUM>), or a combination of linear fastening members and curvilinear fastening members, will provide optimal fit and securement of intervertebral spacer <NUM> between the vertebral bodies. For example, the curvature of the spine at one or more of the vertebral bodies may substantially inhibit the use of the tools and driving members used to install linear fastening members. In such examples, curvilinear fastening members may be selected to secure intervertebral spacer <NUM>. The curvilinear fastening members may be installed through the same linear bore <NUM> that may be configured to receive linear fastening members. Further, the curvilinear fastening members may be installed through the linear bore with a positioning member (described with reference to <FIG>) utilizing a guide member that can be extended only along a linear track.

In one example, one or more curvilinear fasteners may be used to secure intervertebral spacer <NUM> to one vertebral body defining an intervertebral space, while one or more linear fasteners may be used to secure intervertebral spacer <NUM> to the other vertebral body defining the intervertebral space. For example, curvilinear fasteners may be extended through outer bores <NUM> while a linear fastener is extended through central bore <NUM>. Alternatively, linear fastening members may be extended through outer bores <NUM> while a curvilinear fastening member is extended through central bore <NUM>. In yet another example, both linear and curvilinear fastening members may be used to secure the same intervertebral spacer into a given vertebral body. That is, a curvilinear fastening member may be extended through one outer bore <NUM>, while a linear fastening member is extended through the other outer bore <NUM>.

<FIG> depicts an intervertebral spacer <NUM> in accordance with an example of the present disclosure. In some examples, intervertebral spacer <NUM> may be substantially similar to intervertebral spacer <NUM>, or may be another suitable intervertebral spacer. In the example shown in <FIG>, spacer <NUM> may be a generally rectangular spacer defining a cavity <NUM>. Cavity <NUM> may be packed with bone graft or bone-growth inducing materials. Spacer <NUM> may include one or more of inferior surfaces, superior surfaces, biconvex surfaces, among others. In some examples, the surfaces of spacer <NUM> or any other bone contacting surface described in the present disclosure may include one or more of teeth, ridges, friction increasing elements, keels, or gripping or purchasing projections.

Spacer <NUM> may include a plate portion <NUM> that may include one or more features described with reference to plate portion <NUM> of intervertebral spacer <NUM>. In one example, one or more bores <NUM> may disposed through plate portion <NUM>. Though <FIG> depicts two bores <NUM>, those of ordinary skill in the art will recognize that any suitable number of bores may be provided. Bores <NUM> may include one or more features described with reference to bores <NUM> of intervertebral spacer <NUM>. The two bores <NUM> may be angled to guide a fastening member (e.g., a vertebral anchor <NUM> or a bone screw) along differing trajectories. For example, one bore <NUM> may be angled to urge a fastening member along a first trajectory (e.g., toward one of a superior or inferior surface of intervertebral spacer <NUM>), while the other bore <NUM> may be angled to urge a fastening member along a second trajectory (e.g., toward the other of the superior and inferior surface of intervertebral spacer <NUM>). The bores <NUM> can accommodate a straight longitudinal fastening member (e.g., a screw, pin, or the like) and/or a fastening member exhibiting a curvature (e.g., vertebral anchor <NUM> or <NUM>). In some examples, a combination of vertebral anchors <NUM> or <NUM> and conventional screws may be used to install the same intervertebral spacer <NUM> as shown in <FIG>. A circumferential wall defining bores <NUM> may further include one or more recesses <NUM> disposed therein. The one or more recesses <NUM> may be configured to receive one or more protrusions <NUM> disposed on a head portion <NUM> of a vertebral anchor <NUM> (described with reference to <FIG>). Thus, in some examples, recesses <NUM> may be partially-spherical to receive protrusions <NUM>. However, it is contemplated that recesses <NUM> may be formed in any suitable shape configured to receive protrusions <NUM>. Plate portion <NUM> also may include a bore <NUM> having an opening that is disposed through an outer surface of plate portion <NUM>. The bore <NUM> may include one or more features, e.g., threads or other features to engage with an insertion device <NUM> described with further detail below. Intervertebral spacer <NUM> also may include one or more features configured to prevent fastening members from backing out of bores <NUM>, such as, e.g., screws <NUM> described with reference to <FIG>.

Intervertebral spacer <NUM> may be inserted into an intervertebral space between two vertebral bodies in a substantially similar manner as intervertebral spacers <NUM>. In one example, one or more curvilinear fasteners may be used to secure intervertebral spacer <NUM> to one vertebral body defining an intervertebral space, while one or more linear fasteners may be used to secure intervertebral spacer <NUM> to the other vertebral body defining the intervertebral space. For example, a curvilinear fastener may be extended through one bore <NUM> while a linear fastener is extended through the other bore <NUM>.

An insertion device <NUM> is shown in <FIG>, which may be used to position vertebral anchors <NUM> through a plate portion of an intervertebral spacer (e.g., plate portion <NUM> of intervertebral spacer <NUM>) and through a vertebral body. Insertion device <NUM> may extend from a trailing end <NUM> toward a leading end <NUM>. A trailing housing <NUM> may be disposed at trailing end <NUM> and may define one or more elongate channels <NUM>. In the embodiment shown, three elongate channels <NUM> are shown, although any other suitable number of elongate channels <NUM> may be disposed through trailing housing <NUM>. Each of elongate channels <NUM> may receive a guide member <NUM> therethrough. Guide member <NUM> may include a head portion <NUM> and an elongate portion <NUM> that extends away from the head portion <NUM>. In some examples, head portion <NUM> may include one or more flattened and reinforced surfaces configured to receive the force of a striking member (e.g., a hammer or the like). Elongate portion <NUM> may be extended through one or more elongate channels <NUM> toward leading end <NUM>. The distal or leading end of elongate portion <NUM> may include a stepped portion <NUM> (shown in <FIG>). Stepped portion <NUM> may be separated from the remainder of elongate portion <NUM> by a vertical wall <NUM>. In some examples, stepped portion <NUM> may include a smaller cross-sectional dimension (e.g., thickness or width) as compared to a remainder of elongate portion <NUM>.

A connecting housing <NUM> may extend from trailing housing <NUM> toward an anchor housing <NUM> disposed at leading end <NUM>. In some examples, connecting housing <NUM> may be an alignment shaft configured to align elongate channels <NUM> with a corresponding number of anchor channels <NUM> (see <FIG>) disposed in anchor housing <NUM>. In the embodiment shown in <FIG>, connecting housing <NUM> may extend from only one of elongate channels <NUM> to couple trailing housing <NUM> to anchor housing <NUM>. However, those of ordinary skill in the art will appreciate that a shaft <NUM> may extend from more than one elongate channel <NUM> toward anchor housing <NUM>. Guide member <NUM> may extend through an elongate channel <NUM>, through connecting housing <NUM>, and into an anchor channel <NUM>, where it may come into contact with a vertebral anchor <NUM> just before inserting the vertebral anchor <NUM> through a vertebral body, as described further with reference to <FIG>. In some examples, connecting housing <NUM> may merely align certain elongate channels <NUM> in trailing housing <NUM> with anchor channels <NUM> disposed in anchor housing <NUM>. In such examples, elongate portion <NUM> of guide member <NUM> may exit a leading end of elongate channel <NUM> and extend through an open and unconfined space before entering a trailing end of an anchor channel <NUM>.

As best seen in <FIG>, anchor housing <NUM> may include one or more anchor channels <NUM>. Each anchor channel <NUM> may have a variable cross-section along the length of anchor housing <NUM>. In some examples, a given cross-section of anchor channel <NUM> may be t-shaped or any another suitable cross-section. A curvature at the leading end of anchor channel <NUM> may be complimentary to certain portions of a curvilinear anchor (e.g., anchor <NUM> shown in <FIG>). Those portions may include an elongate shank <NUM> and elongate fin <NUM>, shown in <FIG>. That is, anchor channel <NUM> may be defined by a concave surface <NUM> that is complimentary to elongate shank <NUM> of vertebral anchor <NUM>. For example, a laterally extending portion <NUM> of each channel <NUM> may be configured to complement and receive a curved elongate shank <NUM>, and a vertically extending portion <NUM> of each channel <NUM> may receive a curved elongate fin <NUM>. Thus, a vertebral anchor <NUM> may be disposed within each anchor channel <NUM> and may exit anchor channel <NUM> along a given exit trajectory. Some anchor channels <NUM> may urge a vertebral anchor <NUM> along a first exit trajectory <NUM> while other exit channels <NUM> may urge a vertebral anchor <NUM> along a second exit trajectory <NUM>. First exit trajectory <NUM> may extend in a first vertical direction out of the leading end of anchor housing <NUM> while the second, different exit trajectory <NUM> may extend in a second vertical direction out of the trailing end of anchor housing <NUM>. A given anchor housing <NUM> may include a plurality of anchor channels <NUM> that may direct all vertebral anchors <NUM> along the first exit trajectory <NUM>, all vertebral anchors <NUM> along the second exit trajectory <NUM>, or some vertebral anchors <NUM> along the first exit trajectory <NUM> and some vertebral anchors <NUM> along the second exit trajectory <NUM>. Each of first and second trajectories <NUM> and <NUM> may intersect a longitudinal axis of insertion device <NUM> and/or guide member <NUM>. In one example, laterally adjacent anchor channels <NUM> may be configured to direct vertebral anchors <NUM> along different exit trajectories. In the exemplary embodiment shown in <FIG>, anchor housing <NUM> may include three anchor channels <NUM>. Two outer anchor channels <NUM> may be laterally offset from an inner anchor channel <NUM>. The outer anchor channels <NUM> may urge respective vertebral anchors <NUM> along first exit trajectory <NUM> while the inner anchor channel <NUM> may urge a vertebral anchor <NUM> along second exit trajectory <NUM>. Anchor channel <NUM> may further include a stop wall <NUM> (shown in <FIG>) that may extend radially inward from a wall of anchor channel <NUM>. Stop wall <NUM> may be configured to abut a vertical wall of elongate portion <NUM> (of guide member <NUM>) to prevent elongate portion <NUM> from being inserted too far distally into a patient by an operator. Thus, stop wall <NUM> also may prevent an inadvertent excessive force from being applied to intervertebral spacer <NUM> or to a vertebral body by elongate portion <NUM>.

Anchor housing <NUM> includes one or more features to engage with corresponding features disposed on plate portion <NUM> of intervertebral spacer <NUM>. In one example, an extension <NUM> (e.g., a cantilevered snap-fit extension <NUM>) may extend longitudinally outward from the leading end (e.g., a distal face) of anchor housing <NUM>. Extension <NUM> includes one or more surfaces configured to engage channel <NUM> of plate portion <NUM> in a snap fit or other suitable engagement. Anchor housing <NUM> also includes a threaded shank <NUM> that extends longitudinally outward from the leading endface of anchor housing <NUM>. Threaded shank is received by bore <NUM> of plate portion <NUM>. While snap-fit and threaded connections are disclosed in the examples shown by the figures, it should be noted that any other additional or alternative type of engagement may be utilized to couple anchor housing <NUM> to plate portion <NUM>.

Anchor housing <NUM> also may include one or more positioning members <NUM>, as shown in <FIG>. Each positioning member <NUM> may secure a vertebral anchor <NUM> within a respective anchor channel <NUM>. Thus, each anchor channel <NUM> may be associated with its own respective positioning member <NUM>. In one example, positioning member <NUM> may be an elongate cantilever that is coupled to a leading end portion of anchor housing <NUM> via a linkage or hinge <NUM>. In some examples, linkage or hinge <NUM> may be a spring-biased linkage or may be another suitable hinge or linkage. Positioning member <NUM> may extend from linkage <NUM> toward trailing end <NUM>. At its proximal or trailing end, positioning member <NUM> may include a ramp <NUM> and an extension <NUM> spaced from ramp <NUM> by a recess. Ramp <NUM> may be an inclined surface configured to engage elongate portion <NUM> of guide member <NUM>. Positioning member <NUM> may be configured to pivot about the linkage <NUM> and away from an interior of anchor channel <NUM> when ramp <NUM> is engaged by elongate portion <NUM> of guide member <NUM>. In some examples, positioning member <NUM> may pivot in a direction that is opposite to the exit trajectory of its associated anchor channel <NUM>. That is, if a given anchor channel <NUM> is configured to guide a vertebral anchor into a vertebral body along first trajectory <NUM>, the associated positioning member <NUM> of that elongate channel may pivot about linkage <NUM> in the vertical direction that is opposite to the vertical vector of first trajectory <NUM>. On the other hand, if a given anchor channel <NUM> is configured to guide a vertebral anchor <NUM> along the second trajectory <NUM>, the associated positioning member <NUM> of that anchor channel <NUM> may be configured to pivot in a vertical direction that is opposite to the vertical vector of second trajectory <NUM>. Extension <NUM> may include any suitable configuration (e.g., a ball or the like), and may be configured to be releasably coupled to a vertebral anchor <NUM> via groove <NUM>.

Vertebral anchors <NUM> may be loaded into anchor channels <NUM> prior to the coupling of anchor housing <NUM> to plate portion <NUM> of intervertebral spacer <NUM>. Vertebral anchors <NUM> may be loaded from either the trailing end or the leading end of anchor housing <NUM>, if desired. In some examples, vertebral anchors <NUM> may be loaded by a spring-loaded block device. In one example, a vertebral anchor <NUM> may be loaded into the leading end of anchor housing <NUM> with trailing end <NUM> of the vertebral anchor being inserted first. That is, trailing end <NUM> of vertebral anchor <NUM> may be loaded into anchor channels <NUM> before leading end <NUM>. Thus, vertebral anchors <NUM> may be loaded in a reverse manner such that the vertebral anchors <NUM> are loaded in the opposite direction to which they are inserted into the body. As vertebral anchors <NUM> are moved proximally through anchor channels <NUM>, groove <NUM> may be coupled to extension <NUM> of positioning member <NUM>. The docking, mating, or connection of extension <NUM> with groove <NUM> may fix vertebral anchor <NUM> within anchor channel <NUM> until vertebral anchor <NUM> is inserted through a vertebral body. In one example, extension <NUM> may be a ball and a groove <NUM> of vertebral anchor <NUM> may be a socket such that extension <NUM> and groove <NUM> form a ball and socket joint. However, those of ordinary skill in the art will appreciate that any other suitable form of releasable connection may be utilized.

Anchor housing <NUM> may be coupled to intervertebral spacer <NUM> to install vertebral anchors <NUM> into the body. Anchor housing <NUM> and plate portion <NUM> may be aligned via extension <NUM> and channel <NUM>, and/or via shank <NUM> and bore <NUM> in such a manner as to align channels <NUM> of anchor housing <NUM> with bores <NUM> of plate portion <NUM>. The alignment of channels <NUM> and bores <NUM> may permit one or more vertebral anchors <NUM> to be guided from a channel <NUM> through a corresponding bore <NUM> of plate portion <NUM>, and into a vertebral body. Further, the anchor housing <NUM> and plate portion <NUM> may be aligned such that the exit trajectory of a given channel <NUM> may be aligned (e.g., collinear or coplanar) with the exit trajectory of an aligned bore <NUM>. In some examples, the number of channels <NUM> disposed in anchor housing <NUM> may correspond exactly with the number of bores <NUM>. However, it is contemplated that an exact correspondence may not exist between channels <NUM> and bores <NUM>. For example, an anchor housing <NUM> may include fewer channels <NUM> than bores <NUM> in a plate portion. In such examples, anchor housing <NUM> may be coupled to plate portion <NUM> in a number of different configurations. In such examples, after a vertebral anchor <NUM> is inserted through a vertebral body, anchor housing <NUM> may be uncoupled from plate portion <NUM>, reloaded with a new vertebral anchor <NUM>, and recoupled to plate portion <NUM> at a different location.

With continuing reference to <FIG>, there is depicted an exemplary method (not part of the invention) of positioning a vertebral anchor <NUM> via insertion device <NUM>. Referring to <FIG>, vertebral anchor <NUM> is shown loaded into an anchor channel <NUM>. The vertebral anchor <NUM> may be secured within the anchor channel <NUM> via the coupling of extension <NUM> with groove <NUM> of the vertebral anchor <NUM> as set forth above. Elongate portion <NUM> of guide member <NUM> then may be advanced distally (e.g., in the direction of leading end <NUM>) such that the distal end of elongate portion <NUM> may contact ramp <NUM> (<FIG>). In some examples, stepped portion <NUM> of elongate portion <NUM> may contact the ramp <NUM>. Elongate portion <NUM> may be advanced further distally, causing ramp <NUM> to slide vertically upward, thereby disengaging extension <NUM> from groove <NUM> of vertebral anchor <NUM> (<FIG>). As elongate portion <NUM> is advanced further distally, the distal end of elongate portion <NUM> may abut the trailing end <NUM> of vertebral anchor (<FIG>). In some examples, the stepped portion <NUM> of elongate portion <NUM> may abut head portion <NUM> of vertebral anchor <NUM>. Uncoupled from extension <NUM>, vertebral anchor <NUM> then may be advanced out of the leading end of anchor housing <NUM> and anchor channel <NUM> (<FIG>) and ultimately inserted into a vertebral body (not shown) along a given exit trajectory (e.g., trajectory <NUM> or <NUM>. ), as shown in <FIG>. After impacting one vertebral anchor <NUM> through a vertebral body, the same guide member <NUM> (and elongate portion <NUM>) may be withdrawn and reinserted through a different elongate channel <NUM> and anchor channel <NUM> (having another preloaded vertebral anchor <NUM>), to impact a different vertebral anchor <NUM>, if desired. Alternatively, each set of elongate channels may include a dedicated guide member <NUM>.

One embodiment of an insertion device <NUM> is shown in <FIG>. Insertion device <NUM> may extend from a first, trailing end <NUM> toward a second, leading end <NUM>. A base portion <NUM> may include a proximal annular rim <NUM> and base shaft <NUM> extending therefrom. An alignment shaft <NUM> may extend from base shaft <NUM>. In the example shown in <FIG> the leading end <NUM> of alignment shaft <NUM> may have a smaller diameter than the trailing end of alignment shaft <NUM>, although other suitable configurations, including a substantially constant diameter shaft <NUM>, are also contemplated. In some examples, alignment shaft <NUM> may include one or more longitudinally extending windows <NUM>. In some examples, alignment shaft <NUM> may be a hollow elongate shaft accommodating a drive mechanism <NUM> therein. Drive mechanism <NUM> may be configured to actuate a coupling <NUM> disposed at the leading end of alignment shaft <NUM>. Drive mechanism <NUM> may be a spring loaded drive shaft configured to reciprocally move coupling <NUM> between a retracted configuration and an extended configuration. While in the extended configuration, coupling <NUM> may engage with, e.g., bore <NUM> of intervertebral spacer <NUM> to couple insertion device <NUM> to intervertebral spacer <NUM>. While coupling <NUM> is engaged to bore <NUM>, drive mechanism <NUM> may move coupling <NUM> to the retracted configuration to disengage insertion device <NUM> from intervertebral spacer <NUM>.

Coupling <NUM> may be disposed in an anchor housing <NUM> that is disposed at the leading end <NUM> of alignment shaft <NUM>. Anchor housing <NUM> may include at least one anchor channel <NUM>. Anchor channel <NUM> may include one or more features described with reference to anchor channel <NUM> of insertion device <NUM>. For example, anchor channel <NUM> may have a variable cross-section along its length and may have a concave surface <NUM> (shown in <FIG>) that is complimentary to, e.g., elongate shank <NUM> of spacer <NUM> shown in <FIG>. For example, a laterally extending portion of anchor channel <NUM> may receive a curved elongate shank <NUM>. A guide member <NUM> that may be substantially similar to guide member <NUM> may be inserted through anchor channel <NUM> to assist with deploying an anchor disposed therein.

It is contemplated that insertion device <NUM> may include additional or alternative features for attaching to intervertebral spacer <NUM> such as, e.g., positive attachments, cam attachments, threaded attachments or other suitable attachments. In some examples, pins or other members also may prevent the rotation of insertion device <NUM> relative to intervertebral spacer <NUM> when the insertion device <NUM> and intervertebral spacer <NUM> are engaged. In some examples, the leading end of insertion device <NUM> may couple to the anterior face, lateral sides, or other regions of intervertebral spacer <NUM>. In one embodiment, the insertion device <NUM> may include a stop that extends in either the cephalad or caudal direction of a centerline of insertion device <NUM> to prevent the intervertebral spacer <NUM> from being inadvertently impacted undesirably. That is, a stop may extend from the superior or inferior surface of insertion device <NUM> and may contact, e.g., a surface of the intervertebral spacer or vertebral body.

Anchor housing <NUM> may be coupled to an intervertebral spacer, e.g., intervertebral spacer <NUM>, to install vertebral anchors <NUM> into the body. Anchor housing <NUM> and plate portion <NUM> may be aligned via coupling <NUM> and bore <NUM>, in such a manner as to align channel <NUM> of anchor housing <NUM> with a bore <NUM> of plate portion <NUM>. In some examples, anchor channels <NUM> may be laterally offset from the length of alignment shaft <NUM>. The alignment of channel <NUM> and bore <NUM> may permit one or more vertebral anchors <NUM> to be guided from a channel <NUM> through a corresponding bore <NUM> of plate portion <NUM>, and into a vertebral body. Further, the anchor housing <NUM> and plate portion <NUM> may be aligned such that the exit trajectory of a given channel <NUM> may be inline (e.g., collinear or coplanar) with the exit trajectory of an aligned bore <NUM>. While only one anchor channel <NUM> is shown in the example of <FIG>, it is contemplated that additional anchor channels <NUM> may be utilized (e.g., a double or multi-barreled configuration) such that the number of channels <NUM> disposed in anchor housing <NUM> may correspond exactly with the number of bores <NUM> in vertebral spacer <NUM>. In some examples, a guide member may extend through one or more anchor channels <NUM> to simultaneously insert one or more fastening members (e.g., vertebral anchors or screws) through one or more vertebral bodies. Other mechanisms of anchor insertion are also contemplated such as, e.g., a blocking set screw or leaf spring cutout of the spacer or plate that is flexible in the insertion direction and stiff in the expulsion direction. An associated intervertebral spacer also may include rotational stabilizers to add stability to the construct in vivo, and may contain radiographic markers to aid in interoperative visibility.

<FIG> depict an exemplary method (not part of the invention) of positioning a vertebral anchor <NUM> via insertion device <NUM>. Referring to <FIG>, vertebral anchor <NUM> is shown loaded into an anchor channel <NUM>. The vertebral anchor <NUM> may be secured within the anchor channel <NUM> by any suitable mechanism. Guide member <NUM> then may be advanced distally such that the distal end of guide member <NUM> may contact head portion <NUM> of vertebral anchor <NUM> (<FIG>). Guide member <NUM> may extend from trailing end <NUM>, through a trailing opening <NUM> (shown in <FIG>) of anchor channel <NUM> to abut a vertebral anchor <NUM>. Vertebral anchor <NUM> then may be advanced out of the leading end of anchor housing <NUM> and anchor channel <NUM> (<FIG>) and ultimately inserted into a vertebral body (not shown) along a given exit trajectory, as shown in <FIG>. After impacting one vertebral anchor <NUM> through a vertebral body, anchor housing <NUM> may be disengaged from plate portion <NUM>, and another vertebral anchor <NUM> may be loaded into anchor channel <NUM>. When anchor channel <NUM> is reloaded, anchor housing <NUM> may be re-engaged with plate portion <NUM> in a substantially similar manner as before, except that anchor channel <NUM> may be aligned with a different bore <NUM> of vertebral spacer <NUM>.

A vertebral anchor <NUM> shown in <FIG> may extend from a first, trailing end <NUM> toward a second, leading end <NUM>, and may include a head portion <NUM>, an elongate shank <NUM>, and an elongate fin <NUM>. Vertebral anchor <NUM> may be formed from a rigid, bio-compatible material such as, e.g., titanium or polyetheretherketone (PEEK), among others. The head portion <NUM>, elongate shank <NUM>, and elongate fin <NUM> may be formed of the same or of different materials. Portions of vertebral anchor <NUM> may be treated with a titanium and/or hydroxyapatite plasma spray coating to encourage bony on-growth, improving the strength and stability of the connection between the respective component and the underlying bone (e.g., a vertebral body). Any other suitable coating also may be provided on one or more surfaces of vertebral anchor <NUM>. Such coatings may include therapeutic agents (e.g., antibiotic coatings), if desired. Vertebral anchor <NUM> also may include radiopaque markings to facilitate in vivo visualization and insertion. Vertebral anchor <NUM> may be configured to be impacted into vertebral bodies to secure implants within the intervertebral space of a patient. Vertebral anchor <NUM> may be inserted into the patient and impacted through the bone of a vertebral body.

The head portion <NUM> may be disposed at trailing end <NUM> of vertebral anchor <NUM> and may be generally spherical or ball shaped. In some examples, the head portion <NUM> may be shaped in a substantially similar manner as the head portion of other vertebral fastening members (e.g., bone screws). In some examples, the head portion <NUM> may include a bore <NUM> to facilitate removal of vertebral anchor <NUM> from a vertebral body. In some examples, bore <NUM> may be a threaded bore or may include other suitable features to facilitate the extraction of vertebral anchor <NUM> from a vertebral body by, e.g., a pulling tool or the like. In some examples, a tool with a threaded tip may be rotated to threadingly engage bore <NUM>, and the tool may be linearly withdrawn to extract vertebral anchor <NUM> from within a vertebral body. The pooling tool also may include one or more of a cam attachment, an expandable driver, or another feature for removing vertebral anchor <NUM>. A plurality of slots or notches <NUM> may be formed in the outer periphery of head portion <NUM>. In some examples, a plurality of flanges <NUM> may define the plurality of slots <NUM> about the outer periphery of the head portion <NUM>. The flanges <NUM> may be disposed around head portion <NUM> to form a generally t-shaped cross-section. A groove <NUM> (e.g., a semi-cylindrical groove) may be formed in the outer periphery of head portion <NUM>. In some examples, the groove <NUM> may be disposed within one of the flanges <NUM>, or in another suitable location on head portion <NUM>. In some examples, one or more grooves <NUM> may be disposed along the periphery of head portion <NUM>. Groove <NUM> may cooperate with an extension (e.g., extension <NUM> shown in <FIG>) of an installation device as discussed above. In some examples, the flanges <NUM> and slots <NUM> of the head portion <NUM> may cooperate with or be received by complimentary shaped features in a spacer, implant, plate system or the like. The interaction between the flanges <NUM>, slots <NUM>, and the complimentary-shaped features may prevent the relative rotation of vertebral anchor <NUM> before, during and/or after installation of vertebral anchor <NUM> into a vertebral body.

Elongate shank <NUM> may extend away from the head portion <NUM> toward the leading end <NUM>. In some examples, elongate shank <NUM> may be planar and may exhibit a curvature as it extends away from the head portion <NUM>. That is to say, in some examples, elongate shank <NUM> may include a curvilinear configuration. Specifically, elongate shank <NUM> may be curved (e.g., symmetrically curved) about a longitudinal axis. More specifically, elongate shank <NUM> exhibit a curvature about a median longitudinal axis. Further, the elongate shank <NUM> may be curved such that a concave surface <NUM> and a convex surface <NUM> extend from trailing end <NUM> toward leading end <NUM>. The leading end of the elongate shank <NUM> may be formed by a pair of inclined surfaces <NUM> and <NUM> that extend from the lateral ends of elongate shank <NUM> toward an apex <NUM>. Apex <NUM> may be disposed on a longitudinal axis of vertebral anchor <NUM>. Thus, at leading end <NUM>, elongate shank <NUM> may be formed as a projectile point, arrowhead, bladed edge, cutting edge, or the like to facilitate impaction and insertion through bone and/or tissue. To reduce impaction force, the apex <NUM> may feature a hollow style which may be similar to a knife edge. That is, the edge or apex <NUM> of the anchor may approach a shallow angle, e.g., approximately <NUM> degrees at the sharpest point, which may increase closer to a central axis. In some examples, apex <NUM> may be rounded to prevent injury, but may still be sharp around its edges. To further reduce insertion force and manufacturing time, the hollow surfaces may be surface machined using, e.g., a <NUM> full radius mill and, e.g., a <NUM> step-over, which may result in the wavy surface (including a plurality of rolling peaks and valleys) along the face of the hollow surface. As further shown in <FIG>, inclined surfaces <NUM> and <NUM> may include one or more geometric features, such as, e.g., serrations (shown in <FIG>), teeth, tapers, bevels or the like to further facilitate spearing, cutting, slicing, or impacting of elongate shank <NUM> through bone and/or tissue. Inclined surfaces <NUM> and <NUM> also may be formed with an edge (e.g., a v-edge, beveled edge, chisel edge, convex edge or the like) to facilitate impaction.

Elongate fin <NUM> also may extend away from head portion <NUM> toward the leading end <NUM> of vertebral anchor <NUM>. Elongate fin <NUM> also may extend away from the concave surface <NUM> of the elongate shank <NUM>. The vertical periphery of elongate fin <NUM> may be defined by a concave surface <NUM>. In some examples, the elongate shank <NUM> and elongate fin <NUM> may be generally orthogonal to one another and may form a generally t-shaped cross-section. The t-shaped cross-section formed by elongate shank <NUM> and elongate fin <NUM> may reduce impaction forces of vertebral anchor <NUM>, and may increase the torsional stability of vertebral anchor <NUM> as compared to anchors having planar cross-sections. At leading end <NUM>, elongate fin <NUM> may include a ramped surface <NUM> that extends toward apex <NUM>. Ramped surface <NUM> may include one or more of the geometrical features described with reference to inclined surfaces <NUM> and <NUM>. In some examples, a vertical periphery of ramp <NUM> may be beveled and/or have a v-shaped cross-section.

Turning now to <FIG>, a further embodiment of a vertebral anchor <NUM> is depicted. Vertebral anchor <NUM> may extend from a first, trailing end <NUM> toward a second, leading end <NUM>, and may include a head portion <NUM>, an elongate shank <NUM>, and an elongate fin <NUM>. Vertebral anchor <NUM> may be formed from one or more of the materials used to form vertebral anchor <NUM> and may be treated with one or more similar coatings, if desired. Vertebral anchor <NUM> may be inserted into a patient and impacted through bone of a vertebral body.

The head portion <NUM> may be disposed at trailing end <NUM> of vertebral anchor <NUM> and may have a partially spherical outer periphery. In some examples, the head portion <NUM> may be formed by a plurality of spherical segments formed by removing one or more spherical caps from the spherical outer periphery of head portion <NUM>. In the embodiments shown in <FIG>, at least three planar surfaces <NUM>, <NUM>, and <NUM> may define at least a portion of the outer periphery of the partially-spherical head portion <NUM>. In one example, planar surfaces <NUM> and <NUM> may be substantially parallel to one another, and may be substantially orthogonal to planar surface <NUM>. In some examples, planar surface <NUM> may define the proximal-most portion of head portion <NUM> and of vertebral anchor <NUM>. That is, planar surface <NUM> may define the surface that is furthest toward trailing end <NUM> of vertebral anchor <NUM>. A recess (e.g., a concave recess) <NUM> may be disposed within planar surface <NUM> such that planar surface <NUM> may be defined by interrupted hemispherical arc portions, as seen in <FIG>. A bore <NUM> may have an opening disposed within recess <NUM>. Bore <NUM> may extend through head portion <NUM> and may include one or more features described with reference to bore <NUM> of vertebral anchor <NUM>. While not shown in <FIG>, it is contemplated that head portion <NUM> may include other features described with reference to head portion <NUM> of vertebral anchor <NUM>, such as, e.g., grooves and/or mating features configured to secure and position vertebral anchor <NUM> within an anchor channel of an insertion device.

Head portion <NUM> also may include one or more protrusions <NUM> that may extend away from the outer periphery of head portion <NUM>. In the examples shown, protrusions <NUM> may be formed as spherical caps (e.g., partial domes), although protrusions <NUM> may be formed in any other suitable configuration. In some examples, the base of protrusions <NUM> may include an annular rim <NUM> that may, e.g., extend radially away from protrusions <NUM>. In some examples, head portion <NUM> may include two protrusions <NUM> that extend in opposite directions. It is contemplated that another suitable number of protrusions <NUM> may be employed in alternative configurations.

Elongate shank <NUM> may extend away from the head portion <NUM> toward the leading end <NUM>. In some examples, elongate shank <NUM> may be planar and may exhibit a curvature as it extends away from the head portion <NUM>. In some examples, elongate shank <NUM> may be curved (e.g., symmetrically curved) about a longitudinal axis. More specifically, elongate shank <NUM> may exhibit a curvature about a median longitudinal axis. Further, the elongate shank <NUM> may be curved such that a concave surface <NUM> and a convex surface <NUM> extend from trailing end <NUM> toward leading end <NUM>. The leading end of the elongate shank <NUM> may be formed by a pair of inclined surfaces <NUM> and <NUM> that extend from the lateral ends of elongate shank <NUM> toward an apex <NUM>. Apex <NUM> may be disposed on a longitudinal axis of vertebral anchor <NUM>. In some embodiments, apex <NUM> may include a curvilinear periphery. Thus, at leading end <NUM>, elongate shank <NUM> may be formed to include any of the suitable geometries and features disposed on vertebral anchor <NUM> to facilitate impaction.

In one example, the lateral sides of elongate shank <NUM> may include one or more cutouts <NUM>. For example, each lateral side of elongate shank <NUM> may include two cutouts <NUM> to form one or more keels <NUM>. The keels <NUM> may generally extend and point in a reverse manner with respect to a remainder of vertebral anchor <NUM>. That is, the end points of the keels <NUM> may be oriented toward the trailing end <NUM> and not leading end <NUM>. Thus, keels <NUM> may assist in inhibiting vertebral anchor <NUM> from exiting a vertebral body once inserted therein. In the embodiment shown in <FIG>, each lateral side of elongate shank <NUM> may include two cutouts <NUM> and three keels <NUM>, although any other suitable combination of cutouts and keels may be utilized.

One or more apertures <NUM> may disposed through the surface of elongate shank <NUM>. Though depicted as through-holes, apertures 427also may include blind recesses disposed in one or more surfaces of elongate shank <NUM>. Once inserted through the bone of a vertebral body, apertures <NUM> may encourage bony in-growth or on-growth therein, further securing vertebral anchor <NUM> within a respective vertebral body. In some examples, apertures <NUM> may be packed with bone graft or other bone-growth inducing substances.

Elongate fin <NUM> also may extend away from head portion <NUM> toward the leading end <NUM> of vertebral anchor <NUM>. Elongate fin <NUM> also may extend away from the concave surface <NUM> of the elongate shank <NUM>. The vertical periphery of elongate fin <NUM> may be defined by one or more cutouts <NUM> and keels <NUM> in a substantially similar manner as the lateral sides of elongate shank <NUM>. In some examples, the elongate shank <NUM> and elongate fin <NUM> may be generally orthogonal to one another and may form a generally t-shaped cross-section. The t-shaped cross-section formed by elongate shank <NUM> and elongate fin <NUM> may reduce impaction forces of vertebral anchor <NUM>, and may increase the torsional stability of vertebral anchor <NUM> as compared to anchors having planar cross-sections. At leading end <NUM>, elongate fin <NUM> may include a ramped surface <NUM> that extends toward apex <NUM>. Ramped surface <NUM> may include one or more of the geometrical features described with reference to inclined surfaces <NUM> and <NUM>. In some examples, apertures (not shown but similar to apertures <NUM>) may be disposed on or through elongate fin <NUM> to encourage bony in-growth or on-growth therein.

In some examples, vertebral anchors <NUM> and <NUM> may facilitate easy insertion of various vertebral spacers (e.g., stand-alone ACDF and/or ALIF spacers) through the use of inline impaction of anchors <NUM> and <NUM> through the spacer. In some examples, the inline operation may be facilitated through appropriate implant design, instrument design, and design of the implant-instrument interface. In some examples, the various examples of the present disclosure may permit the use of stand-alone spacers at the most caudal or most cephalad cervical disc spaces (e.g., C5-C6/C6-C7 and C2-C3), and at the caudal lumbar levels (e.g., L5-S1) where angled instruments may pose insertion problems due to interference with tissue or other anatomy.

Any aspect set forth in any example may be used with any other example set forth herein. Every device and apparatus set forth herein may be used in a suitable medical procedure, such as, e.g., a vertebral disc replacement procedure, and may be advanced through any suitable body lumen, body cavity, or incision.

Claim 1:
A system for inserting a vertebral anchor (<NUM>, <NUM>) into a vertebral body, the system comprising:
an intervertebral spacer (<NUM>, <NUM>) having at least one bore (<NUM>, <NUM>) with a generally circular cross-section;
at least one vertebral anchor (<NUM>, <NUM>) capable of being received in the at least one bore (<NUM>, <NUM>);
an insertion device (<NUM>) configured for positioning the vertebral anchor (<NUM>, <NUM>) through a plate portion (<NUM>) of the intervertebral spacer (<NUM>, <NUM>), characterized in that the insertion device (<NUM>) comprises:
a trailing housing (<NUM>) defining one or more elongate channels (<NUM>);
an anchor housing (<NUM>) defining one or more anchor channels (<NUM>), a first anchor channel of the one or more anchor channels being configured to guide the vertebral anchor (<NUM>, <NUM>) out of a distal end of the anchor housing (<NUM>) along a first trajectory; and
a guide member (<NUM>) configured to extend through a first elongate channel of the one or more elongate channels (<NUM>) and the first anchor channel (<NUM>), the guide member (<NUM>) configured to move along a first longitudinal axis when disposed within the first elongate channel and the first anchor channel and abut the vertebral anchor (<NUM>, <NUM>) disposed within the first anchor channel (<NUM>),
wherein the first longitudinal axis and the first trajectory intersect one another, characterized in that
the anchor housing (<NUM>) includes one or more features to engage with corresponding features disposed on a plate portion (<NUM>) of an intervertebral spacer (<NUM>), the features comprising a threaded shank (<NUM>) extending longitudinally outward from a leading face of the anchor housing (<NUM>) configured to be received in a threaded bore (<NUM>) of the plate portion (<NUM>) of the intervertebral spacer (<NUM>) and an extension (<NUM>) extending longitudinally outward from the leading face of the anchor housing to (<NUM>) be received in a channel (<NUM>) of the plate portion (<NUM>) of the intervertebral spacer (<NUM>).