Patent Description:
Spinal fixation procedures utilizing intervertebral spacers can be used to correct spinal conditions such as degenerative disc disease, spondylolisthesis, spinal deformities, or other spinal conditions through minimally invasive or invasive spinal surgery. For example, intervertebral discs can degenerate or otherwise become damaged over time. In some instances, an intervertebral spacer can be positioned within a space previously occupied by a disc between adjacent vertebral bodies. Such intervertebral spacers can help maintain a desired spacing between adjacent vertebrae and/or promote fusion between adjacent vertebrae. The use of bone graft and/or other materials within an intervertebral spacer can also facilitate the fusion of adjacent vertebral bodies. Accordingly, a need exists for improved intervertebral spacers and related surgical instrumentation, tools, systems and methods (not forming part of the claimed invention).

The various systems and methods (not forming part of the claimed invention) of the present disclosure have been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available surgical devices, instruments, systems, and methods for implanting intervertebral spacers between vertebral bodies of a patient.

The present invention relates to an intervertebral spacer according to claim <NUM> and a spinal fusion system with said spacer and an insertion tool according to claim <NUM>. According to the invention, an intervertebral spacer may include a superior surface configured to engage a superior vertebral body, an inferior surface configured to engage an inferior vertebral body, and a peripheral wall extending from the superior surface to the inferior surface. The peripheral wall has a distal end and a proximal end that includes a cam surface that is rotatable against a complementary cam surface of an inserter tool such that a first force causes the intervertebral spacer to pivot, relative to the inserter tool, about a pivot point associated with the cam surface.

In other embodiments, a spinal fusion system may include an intervertebral spacer and an inserter tool. The intervertebral spacer may include a superior surface configured to engage a superior vertebral body, an inferior surface configured to engage an inferior vertebral body, and a peripheral wall extending from the superior surface to the inferior surface. The peripheral wall may have a distal end and a proximal end comprising a cam surface that is rotatable against a complementary cam surface such that a first force causes the intervertebral spacer to pivot about a pivot point associated with the cam surface. The inserter tool may include a shroud having a proximal end and a distal end, a handle located toward the proximal end of the shroud, and a cam lobe located at the distal end of the shroud, with the shroud extending between the handle and the cam lobe. The cam lobe may be configured to impart the first force to the cam surface that causes the intervertebral spacer to pivot about the pivot point associated with the cam surface.

In yet other embodiments, a method for (not forming part of the present invention) an intervertebral spacer comprising a cam surface between two vertebral bodies of a patient through use of an inserter tool that comprises a complimentarily shaped cam lobe configured to engage the cam surface and permit selective rotation of the intervertebral spacer relative to the inserter tool may include aligning the cam surface of the intervertebral spacer with the complimentarily shaped cam lobe of the inserter tool. The method may also include moving the cam surface into engagement with the complimentarily shaped cam lobe and inserting the intervertebral spacer between the two vertebral bodies of the patient.

These and other features and advantages of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the systems and methods set forth hereinafter.

Exemplary embodiments of the disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. While the implantation methods described herein do not form part of the invention, they are disclosed as they represent useful background for understanding the invention. Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the scope of the appended claims, the exemplary embodiments of the present disclosure will be described with additional specificity and detail through use of the accompanying drawings in which:.

It is to be understood that the drawings are for purposes of illustrating the concepts of the disclosure and may not be drawn to scale. Furthermore, the drawings illustrate exemplary embodiments and do not represent limitations to the scope of the present disclosure.

Exemplary embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present disclosure, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus and method, as represented in the Figures, is not intended to limit the scope of the present disclosure, as claimed in this or any other application claiming priority to this application, but is merely representative of exemplary embodiments of the present disclosure.

Standard medical directions, planes of reference, and descriptive terminology are employed in this specification. For example, anterior means toward the front of the body. Posterior means toward the back of the body. Superior means toward the head. Inferior means toward the feet. Medial means toward the midline of the body. Lateral means away from the midline of the body. Axial means toward a central axis of the body. Abaxial means away from a central axis of the body. Ipsilateral means on the same side of the body. Contralateral means on the opposite side of the body. A sagittal plane divides a body into right and left portions. A midsagittal plane divides the body into bilaterally symmetric right and left halves. A coronal plane divides a body into anterior and posterior portions. A transverse plane divides a body into superior and inferior portions. These descriptive terms may be applied to an animate or inanimate body.

The phrases "connected to," "coupled to," "engaged with," and "in communication with" refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be functionally coupled to each other even though they are not in direct contact with each other. The term "abutting" refers to items that are in direct physical contact with each other, although the items may not necessarily be attached together. The phrase "fluid communication" refers to two features that are connected such that a fluid within one feature is able to pass into the other feature.

<FIG> illustrate various views of an intervertebral spacer <NUM>, according to an embodiment of the present disclosure. Specifically, <FIG> is a perspective top view of a proximal end <NUM> of the intervertebral spacer <NUM>; <FIG> is a perspective top view of a distal end <NUM> of the intervertebral spacer <NUM>; <FIG> is a top view of the intervertebral spacer <NUM>; <FIG> is a bottom view of the intervertebral spacer <NUM>; <FIG> illustrates a first side <NUM> of the intervertebral spacer <NUM>; <FIG> illustrates a second side <NUM> of the intervertebral spacer <NUM>; <FIG> is a perspective view of the distal end <NUM> of the intervertebral spacer <NUM>; and <FIG> is a perspective view of the proximal end <NUM> of the intervertebral spacer <NUM>.

The intervertebral spacer <NUM> may generally include a superior surface <NUM> configured to engage a superior vertebral body (not shown), an inferior surface <NUM> configured to engage an inferior vertebral body (not shown), and a peripheral wall <NUM> extending from the superior surface <NUM> to the inferior surface <NUM>. The peripheral wall <NUM> may generally comprise the distal end <NUM>, the proximal end <NUM>, the first side <NUM>, and the second side <NUM> of the intervertebral spacer <NUM>.

The proximal end <NUM> of the intervertebral spacer <NUM> may include a cam surface <NUM> that is rotatable against a complementary cam surface of a suitable inserter tool such that a first force causes the intervertebral spacer <NUM> to pivot, relative to the inserter tool, about a pivot point <NUM> associated with the cam surface <NUM>, as will be discussed in more detail below with respect to <FIG>. The cam surface <NUM> may comprise a concave surface having a first radius of curvature <NUM>, as shown in <FIG>. In at least one embodiment, the first radius of curvature <NUM> may be about <NUM>. In other embodiments, the first radius of curvature <NUM> may be between about <NUM> and about <NUM>. However, it will be understood that in other embodiments (not shown), the cam surface <NUM> may alternatively comprise a convex surface. The cam surface <NUM> may also be located closer to the first side <NUM> of the intervertebral spacer <NUM> than the second side <NUM> of the intervertebral spacer <NUM>, or vice versa.

The proximal end <NUM> of the intervertebral spacer <NUM> may also include an aperture <NUM> formed therein, as well as a chamfered surface <NUM> proximate the aperture <NUM>. The chamfered surface <NUM> may be configured to receive a second force from a suitable inserter shaft tip to aid the first force in pivoting the intervertebral spacer <NUM> about the pivot point <NUM> associated with the cam surface <NUM>, as will be discussed in more detail below with respect to <FIG>. Moreover, the aperture <NUM> includes threading <NUM> formed within the aperture <NUM> to facilitate coupling of the intervertebral spacer <NUM> to a suitable inserter shaft, which will also be discussed in more detail below with respect to <FIG>.

As shown in <FIG>, the superior surface <NUM> of the intervertebral spacer <NUM> may comprise a third radius of curvature <NUM> that extends from the proximal end <NUM> of the intervertebral spacer <NUM> to the distal end <NUM> of the intervertebral spacer <NUM>. Likewise, the inferior surface <NUM> of the intervertebral spacer <NUM> may comprise a fourth radius of curvature <NUM> that extends from the proximal end <NUM> of the intervertebral spacer <NUM> to the distal end <NUM> of the intervertebral spacer <NUM>, as shown in <FIG>.

In at least one embodiment, the fourth radius of curvature <NUM> may be substantially equal to the third radius of curvature <NUM>. As defined herein, "substantially equal to" means "equal to," or within about a + or - <NUM>% relative variance from one another.

In some embodiments, the third and fourth radii of curvatures <NUM>, <NUM> may each range from about <NUM> to about <NUM>.

In a particular embodiment, the third and fourth radii of curvatures <NUM>, <NUM> may each be about <NUM>.

As shown in <FIG>, the superior surface <NUM> of the intervertebral spacer <NUM> may comprise a fifth radius of curvature <NUM> that extends from the first side <NUM> of the intervertebral spacer <NUM> to the second side <NUM> of the intervertebral spacer <NUM>. Likewise, the inferior surface <NUM> of the intervertebral spacer <NUM> may comprise a sixth radius of curvature <NUM> that extends from the first side <NUM> of the intervertebral spacer <NUM> to the second side <NUM> of the intervertebral spacer <NUM>, as shown in <FIG>.

In at least one embodiment, the sixth radius of curvature <NUM> may be substantially equal to the fifth radius of curvature <NUM>.

In some embodiments, the fifth and sixth radii of curvatures <NUM>, <NUM> may each range from about <NUM> to about <NUM>.

In a particular embodiment, fifth and sixth radii of curvatures <NUM>, <NUM> may each be about <NUM>.

In this manner, the third, fourth, fifth, and sixth radii of curvatures <NUM>, <NUM>, <NUM>, <NUM> of the superior and inferior surfaces <NUM>, <NUM> of the intervertebral spacer <NUM> may together result in a dome shape with "high spots" (or maximal thickness of the intervertebral spacer <NUM>) toward the centers of the superior and inferior surfaces <NUM>, <NUM>. These high spots may help reduce frictional forces acting upon the superior and inferior surfaces <NUM>, <NUM> when the intervertebral spacer <NUM> is inserted between two vertebral bodies. In this manner, these high spots may help reduce the force needed to rotate the intervertebral spacer <NUM> after it has been inserted between two vertebral bodies, as will be discussed below in more detail with respect to <FIG>.

The intervertebral spacer <NUM> may include a central bone graft aperture <NUM> formed through the superior and inferior surfaces <NUM>, <NUM> of the intervertebral spacer <NUM>, as well as one or more side bone graft apertures <NUM> formed in the first and second sides <NUM>, <NUM> of the intervertebral spacer <NUM>. The central bone graft aperture <NUM> and the one or more side bone graft apertures <NUM> may each be configured to receive bone graft material (not shown) and/or other suitable materials that are known in the art. The intervertebral spacer <NUM> may also include one or more serrated teeth <NUM> formed in the superior and inferior surfaces <NUM>, <NUM> of the intervertebral spacer <NUM>. The one or more serrated teeth <NUM> may be configured to help stabilize the intervertebral spacer <NUM> between adjacent vertebral bodies during the fusion process. Moreover, bone graft and/or other suitable materials may also be placed between adjacent serrated teeth <NUM> of the intervertebral spacer <NUM> in order to enhance the fusion process and/or help stabilize the intervertebral spacer <NUM> between adjacent vertebral bodies during the fusion process.

The intervertebral spacer <NUM> may also include one or more first marker apertures <NUM> and a second marker aperture <NUM>. The one or more first marker apertures <NUM> may each be configured to receive a first radiopaque maker <NUM>, as shown in <FIG>. The second marker aperture <NUM> may be configured to receive a second radiopaque maker <NUM>, as shown in <FIG>. The first and second radiopaque makers <NUM>, <NUM> may be made from any suitable radiopaque material, such as tantalum (as one non-limiting example). The first and second radiopaque makers <NUM>, <NUM> may be respectively inserted into the first and second marker apertures <NUM>, <NUM> in order to couple the first and second radiopaque makers <NUM>, <NUM> to the intervertebral spacer <NUM>, as can be seen in the exploded view shown in <FIG>. In this manner, the first and second radiopaque makers <NUM>, <NUM> may be used to verify whether or not the intervertebral spacer <NUM> has been correctly placed between adjacent vertebral bodies via a suitable x-ray imaging process, which may be performed intraoperatively and/or postoperatively.

<FIG> illustrate various views of differently sized intervertebral spacers, according to embodiments of the present disclosure. Specifically, <FIG> illustrate various views of an intervertebral spacer <NUM> having a height "H" (see <FIG>) of about <NUM> and a length "L" (see <FIG>) of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>; and <FIG> illustrate various views of an intervertebral spacer <NUM> having a height of about <NUM> and a length of about <NUM>.

<FIG> illustrate various views of an inserter tool <NUM> and its components, according to an embodiment of the present disclosure. Specifically, <FIG> is a perspective top view of a proximal end <NUM> of the inserter tool <NUM>; <FIG> is a perspective top view of a distal end <NUM> of the inserter tool <NUM>; <FIG> is a top view of the inserter tool <NUM>; <FIG> is a bottom view of the inserter tool <NUM>; <FIG> is a right side view of the inserter tool <NUM>; <FIG> is a left side view of the inserter tool <NUM>; <FIG> illustrates the distal end <NUM> of the inserter tool <NUM> with an extended inserter shaft tip <NUM>; <FIG> illustrates the distal end <NUM> of the inserter tool <NUM> with a retracted inserter shaft tip <NUM>; <FIG> is a perspective side view of the proximal end <NUM> of a shroud <NUM> of the inserter tool <NUM>; <FIG> is a perspective side view of the distal end <NUM> of the shroud <NUM>; <FIG> is a close-up perspective view of the distal end <NUM> of the shroud <NUM> illustrating a cam lobe <NUM>; <FIG> is a close-up side view of the distal end <NUM> of the shroud <NUM> illustrating the cam lobe <NUM>; <FIG> is a perspective view of a proximal end <NUM> of an inserter shaft <NUM> of the inserter tool <NUM>; <FIG> is a perspective view of a distal end <NUM> of the inserter shaft <NUM>; <FIG> is a close-up perspective view of the distal end <NUM> of the inserter shaft <NUM>; and <FIG> is a close-up side view of the distal end <NUM> of the inserter shaft <NUM>.

As shown in <FIG>, the inserter tool <NUM> may generally comprise the shroud <NUM>, the inserter shaft <NUM> (enclosed by the shroud <NUM>), a handle <NUM> located toward the proximal end <NUM> of the shroud <NUM>, and the cam lobe <NUM> located at the distal end <NUM> of the shroud <NUM>. The handle <NUM> may be coupled to the shroud <NUM> via a shroud stem <NUM> (see <FIG> and <FIG>) and the shroud <NUM> may generally extend between the handle <NUM> and the cam lobe <NUM>.

As shown in <FIG>, the inserter shaft <NUM> may be coupled to a knob <NUM> at its proximal end <NUM> and have the inserter shaft tip <NUM> at its distal end <NUM>. The knob <NUM> may be accessible through a window <NUM> formed in the shroud <NUM> (see <FIG> and <FIG>). The knob <NUM> may be translated distally with respect to the shroud <NUM> (as indicated by arrow <NUM> shown in <FIG>) to extend the inserter shaft tip <NUM> from the distal end <NUM> of the shroud <NUM> through the inserter shaft aperture <NUM> (see <FIG>). The knob <NUM> may also be translated proximally with respect to the shroud <NUM> (as indicated by arrow <NUM> shown in <FIG>) to retract the inserter shaft tip <NUM> into the distal end <NUM> of the shroud <NUM>.

As shown in <FIG>, the inserter shaft tip <NUM> may have a conical shape that is configured to engage the chamfered surface <NUM> formed in the intervertebral spacer <NUM>, as will be discussed in more detail below with respect to <FIG>. The inserter shaft <NUM> may also include threading <NUM> formed along the inserter shaft <NUM> proximate the inserter shaft tip <NUM>. In this manner, the inserter shaft <NUM> may be removably couplable to the intervertebral spacer <NUM> by rotating the inserter shaft <NUM> relative to the intervertebral spacer <NUM> to engage the threading <NUM> of the inserter shaft <NUM> (i.e., first threading) with the threading <NUM> formed in the intervertebral spacer <NUM> (i.e., second threading).

As shown in <FIG>, the cam lobe <NUM> may comprise a complementarily shaped convex cam lobe surface <NUM> having a second radius of curvature <NUM> that is substantially equal to the first radius of curvature <NUM> shown in <FIG>. However, it will be understood that in other embodiments, the cam lobe <NUM> may alternatively comprise a concave surface that is complementarily shaped to a convex cam surface formed in a suitable intervertebral spacer (not shown).

In this application, surfaces that are "complementary" or "complementarily shaped" are surfaces that are shaped to follow similar pathways. In some embodiments, complementarily shaped surfaces may be concave and convex, respectively. Further, in some exemplary embodiment, complementarily shaped surfaces may have arcuate shapes. The radii of curvature of complementarily shaped surfaces may be similar, for example, with the surface having a concave curvature having a radius of curvature slightly larger than the radius of curvature of the convex surface. However, complementary surfaces, or complementarily shaped surfaces, need not, in all embodiments, be concave and convex (respectively), arcuate, or possessed of similar radii of curvature.

In at least one embodiment, the cam lobe <NUM> may be located closer to the top of the shroud <NUM> above a distal surface <NUM>. In this embodiment, the distal surface <NUM> of the shroud <NUM> may be concave. However, it will also be understood that in other embodiments (not shown), the cam lobe <NUM> may be located closer to the bottom of the shroud <NUM> below a distal surface of the shroud <NUM>, and the distal surface of the shroud <NUM> may be at least partially concave, convex, and/or straight.

<FIG> illustrate various spinal fusion systems including an intervertebral spacer <NUM> and an inserter tool <NUM> during various stages of operation. Specifically, <FIG> illustrates a spinal fusion system <NUM> prior to assembly; <FIG> illustrates the spinal fusion system <NUM> after assembly; <FIG> illustrates a spinal fusion system <NUM> with the intervertebral spacer <NUM> partially rotated via a first force <NUM>; <FIG> illustrates a spinal fusion system <NUM> with the intervertebral spacer <NUM> partially rotated via the first force <NUM> and a second force <NUM>; <FIG> illustrates a spinal fusion system <NUM> with the intervertebral spacer <NUM> fully rotated via the first force <NUM>; and <FIG> illustrates a spinal fusion system <NUM> with the intervertebral spacer <NUM> fully rotated via the first force <NUM> and the second force <NUM>.

<FIG> illustrate how the intervertebral spacer <NUM> may be removably coupled to the inserter tool <NUM>. This may be accomplished by aligning the cam surface <NUM> with the cam lobe <NUM>, moving the cam surface <NUM> into engagement with the complimentarily shaped cam lobe <NUM> (see arrow <NUM> in <FIG>), and engaging the threading <NUM> of the inserter shaft <NUM> with the threading <NUM> of the intervertebral spacer <NUM> to removably couple the intervertebral spacer <NUM> to the inserter shaft <NUM> (and thus the inserter tool <NUM>), as shown in <FIG>.

<FIG> and <FIG> illustrate how the cam surface <NUM> of the intervertebral spacer <NUM> is rotatable against the complementary cam lobe surface <NUM> of the cam lobe <NUM> coupled to the inserter tool <NUM>, such that a first force <NUM> causes the intervertebral spacer <NUM> to pivot, relative to the inserter tool <NUM>, about the pivot point <NUM> associated with the cam surface <NUM>. In these embodiments, the cam lobe <NUM> is configured to impart the first force <NUM> to the cam surface <NUM> as the inserter tool <NUM> is pushed distally, causing the intervertebral spacer <NUM> to pivot about the pivot point <NUM> associated with the cam surface <NUM>. As previously discussed, frictional forces may act upon the superior and inferior surfaces <NUM>, <NUM> of the intervertebral spacer <NUM> when it is inserted between two vertebral bodies. In this manner, the frictional forces imparted on the intervertebral spacer <NUM> by the vertebral bodies may act to oppose the first force <NUM> and help facilitate rotation of the intervertebral spacer <NUM> as it is inserted between the vertebral bodies.

<FIG> and <FIG> show how the chamfered surface <NUM> of the intervertebral spacer <NUM> is configured to receive a second force <NUM> from the inserter shaft tip <NUM> to further aid the first force <NUM> in pivoting the intervertebral spacer <NUM> about the pivot point <NUM> associated with the cam surface <NUM>. This may be accomplished by pushing the inserter shaft <NUM> distally, causing the inserter shaft tip <NUM> to engage the chamfered surface <NUM> of the intervertebral spacer <NUM> and pivot the intervertebral spacer <NUM> about the pivot point <NUM> associated with the cam surface <NUM>. In a similar manner, the frictional forces imparted on the intervertebral spacer <NUM> by the vertebral bodies may act to oppose both of the first and second forces <NUM>, <NUM> and help facilitate rotation of the intervertebral spacer <NUM> as it is inserted between the vertebral bodies.

<FIG> illustrate an example implantation process <NUM> for an intervertebral spacer <NUM> relative to a vertebral body <NUM>, according to one embodiment of the present disclosure. Specifically, <FIG> illustrates the intervertebral spacer <NUM> inserted into the disc space above the vertebral body <NUM> during a transforaminal insertion procedure; <FIG> illustrates rotation of the intervertebral spacer <NUM> relative to the vertebral body <NUM> via one or more of the processes described above with respect to <FIG>; and <FIG> illustrates final placement of the intervertebral spacer <NUM> relative to the vertebral body <NUM> with the inserter tool <NUM> decoupled from the intervertebral spacer <NUM> and removed from the surgical site.

<FIG> illustrate another example implantation process <NUM> for one or more intervertebral spacers <NUM> relative to a vertebral body <NUM>, according to another embodiment of the present disclosure. Specifically, <FIG> illustrates one intervertebral spacer <NUM> inserted into the disc space above the vertebral body <NUM> during a posterior insertion procedure, with the aid of a tool <NUM> providing distraction during the insertion process, and <FIG> illustrates final placement of two intervertebral spacers <NUM> relative to the vertebral body <NUM>.

<FIG> illustrates a flowchart of a method <NUM> (not forming part of the claimed invention) for inserting an intervertebral spacer between two vertebral bodies of a patient, according to an embodiment of the present disclosure. In general, the method <NUM> may include the use of an intervertebral spacer comprising a cam surface and an inserter tool that comprises a complimentarily shaped cam lobe configured to engage the cam surface and permit selective rotation of the intervertebral spacer relative to the inserter tool. The inserter tool may also comprise an inserter shaft with first threading and the intervertebral spacer may additionally comprises an aperture with second threading. The inserter shaft further comprise an inserter shaft tip and the intervertebral spacer may also comprise a chamfered surface proximate the aperture.

The method <NUM> may begin with a step <NUM> in which the cam surface of the intervertebral spacer may be aligned with the complimentarily shaped cam lobe of the inserter tool.

Once the cam surface of the intervertebral spacer has been aligned with the complimentarily shaped cam lobe of the inserter tool, the method <NUM> may proceed to a step <NUM> in which the cam surface may be moved into engagement with the complimentarily shaped cam lobe and the first threading of the inserter shaft may be engaged with the second threading of the intervertebral spacer to removably couple the intervertebral spacer to the inserter shaft.

Once the intervertebral spacer has been removably coupled to the inserter shaft, the method <NUM> may proceed to a step <NUM> in which the intervertebral spacer may be inserted between the two vertebral bodies of the patient.

Alternatively, or in addition thereto, once the intervertebral spacer has been inserted between the two vertebral bodies of the patient, the method <NUM> may proceed to a step <NUM> in which a first force may be applied to the cam surface with the complimentarily shaped cam lobe to cause the intervertebral spacer to pivot, relative to the inserter tool, about a pivot point associated with the cam surface.

Alternatively, or in addition thereto, the method <NUM> may proceed to a step <NUM> in which a second force may be applied to the chamfered surface with the inserter shaft tip to aid the first force in pivoting the intervertebral spacer about the pivot point associated with the cam surface.

Alternatively, or in addition thereto, the method <NUM> may proceed to a step <NUM> in which the first threading of the inserter shaft may be disengaged with the second threading of the intervertebral spacer, the inserter shaft may be removed from the patient, and the method <NUM> may end.

Any methods disclosed herein comprise one or more steps or actions for performing the described method. One or more of the method steps and/or actions may be omitted from and of the methods disclosed herein. Moreover, any of the method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.

Reference throughout this specification to "an embodiment" or "the embodiment" means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment.

Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim requires more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment.

Recitation in the claims of the term "first" with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles set forth herein.

Claim 1:
An intervertebral spacer (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising:
a superior surface (<NUM>) configured to engage a superior vertebral body;
an inferior surface (<NUM>) configured to engage an inferior vertebral body; and
a peripheral wall (<NUM>) extending from the superior surface to the inferior surface, the peripheral wall comprising:
a distal end (<NUM>); and
a proximal end (<NUM>) comprising: a cam surface (<NUM>) that is rotatable against a complementary cam lobe (<NUM>) surface of an inserter tool (<NUM>) such that a first force (<NUM>) causes the intervertebral spacer to pivot, relative to the inserter tool, about a pivot point (<NUM>) associated with the cam surface; and an aperture (<NUM>),
wherein:
the cam surface comprises a concave surface having a first radius of curvature (<NUM>), the concave surface configured to receive the cam lobe comprising a complementarily shaped convex surface having a second radius of curvature (<NUM>) that is substantially equal to the first radius of curvature; and
the aperture includes a first threading (<NUM>) formed within the aperture to facilitate coupling of the intervertebral spacer to the inserter shaft of the inserter tool.