Patent Description:
Spinal deformities may result from disease, age, or trauma causing destabilization of the spine. To correct destabilization of a patient's spine, posterior fusion device systems may be used. The posterior fusion device systems that are currently available are designed to be applicable to single and multiple level stabilizations. These posterior fusion device systems and the instrumentation used for insertion into a patient's spine are extensive, complicated, and expensive.

<CIT> and <CIT> disclose a single level fusion systems according to the prior art.

Embodiments of the present invention provide single level fusion systems that can maintain or re-establish anatomic spacing within a patient's spine. Some of the methods and procedures disclosed herein do not form part of the presently claimed invention, but are useful in understanding the implementation, usefulness and advantages of the presently claimed invention.

The present invention is defined in claim <NUM> while preferred embodiments are set forth in the dependent claims <NUM>-<NUM>.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the detailed description herein, serve to explain the principles of the invention. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention.

Generally stated, disclosed herein are single level fusion systems. Further, surgical methods (not claimed) for inserting the single level fusion systems are discussed.

In this detailed description and the following claims, the words proximal, distal, anterior, posterior, medial, lateral, superior, inferior, cephalad and caudally are defined by their standard usage for indicating a particular part of a bone or implant according to the relative disposition of the natural bone or directional terms of reference. For example, "proximal" means the portion of an implant nearest the insertion instrument, while "distal" indicates the portion of the implant farthest from the insertion instrument. As for directional terms, "anterior" is a direction towards the front side of the body, "posterior" means a direction towards the back side of the body, "medial" means towards the midline of the body, "lateral" is a direction towards the sides or away from the midline of the body, "superior" means a direction above and "inferior" means a direction below another object or structure, "cephalad" means a direction toward the head and "caudally" means a direction toward the inferior part of the body.

Referring to the drawings, wherein like reference numerals are used to indicate like or analogous components throughout the several views, and with particular reference to <FIG>, there is illustrated an exemplary embodiment of a single level fusion system <NUM>. The single level fusion system <NUM> may include a first fastener assembly <NUM>, a second fastener assembly <NUM>, and an elongate member <NUM>.

With continued reference to <FIG>, the first fastener assembly <NUM> may include a first fastener <NUM> and a set screw <NUM>. The first fastener <NUM> may have a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> may be, for example, threaded along its entire length, threaded along only a portion of the length, or non-threaded. As shown in <FIG>, the head <NUM> may include a first arm <NUM>, a second arm <NUM>, and a passageway <NUM> extending between the first arm <NUM> and the second arm <NUM>. The first arm <NUM> and second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be, for example, planar, as shown, or alternatively may be curved concavely or convexly. The first arm <NUM> and second arm <NUM> may have, for example, a threaded portion <NUM> that extends along at least a portion of the interior surface of the first arm <NUM> and the second arm <NUM> from the top surface of the first and second arms <NUM>, <NUM> toward the base <NUM>.

As shown in <FIG>, the set screw <NUM> may include a top surface <NUM> and a bottom surface <NUM>. The set screw <NUM> may also include a tool engagement opening <NUM> extending into the set screw <NUM> from the top surface <NUM> toward the bottom surface <NUM>. In addition, the set screw <NUM> may include threads <NUM> on the exterior surface extending from the top surface <NUM> to the bottom surface <NUM>.

The second fastener assembly <NUM>, as shown in <FIG> and <FIG>, may include a second fastener <NUM> and a hinge member <NUM>. The second fastener <NUM> may have a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> may be, for example, threaded along its entire length, threaded along only a portion of its length, or non-threaded. As shown in <FIG>, the head <NUM> may include a first arm <NUM>, a second arm <NUM>, and a passageway <NUM> extending between the first arm <NUM> and the second arm <NUM>. The first arm <NUM> and the second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the head <NUM>. The first arm <NUM> and second arm <NUM> may, for example, each include an opening <NUM> extending from the interior surface to an exterior surface of the arms <NUM>, <NUM>.

Although the fasteners shown throughout the present description, such as fasteners <NUM>, <NUM>, are shown as being straight, it is also contemplated that the fasteners may have curved shafts that may be driven into the patient's vertebrae rather than screwed.

As shown in <FIG> and <FIG>, at least one hinge member <NUM> may be positioned within the openings <NUM> in the first arm <NUM> and the second arm <NUM>. The at least one hinge member <NUM> may also, for example, pass through the elongate member <NUM> to secure the elongate member <NUM> to the second fastener <NUM>.

The elongate member <NUM> may include a first end <NUM> and a second end <NUM>, as shown in <FIG>. In one embodiment, it is contemplated that the elongate member <NUM> may include an opening (not shown) near the second end <NUM> to receive the at least one hinge member <NUM>. In an alternative embodiment, it is contemplated that the elongate member <NUM> may include at least one hinge member <NUM> coupled to the second end <NUM> of the elongate member <NUM>. Alternative attachment mechanisms, as known by one of ordinary skill in the art, which enable the elongate member <NUM> to rotate with respect to the second fastener <NUM> are also contemplated.

The system <NUM> may be implanted by first obtaining a first fastener assembly <NUM>, a second fastener assembly <NUM>, and an elongate member <NUM>. Next, the elongate member <NUM> may be coupled to the second fastener assembly <NUM> by inserting the hinge member <NUM> into the openings <NUM> in the second fastener <NUM> to secure the elongate member <NUM> to the second fastener <NUM>. Then the first fastener <NUM> and second fastener assembly <NUM> with the attached elongate member <NUM> may each be inserted into the desired vertebrae. After insertion of the first fastener <NUM> and the second fastener <NUM>, the elongate member <NUM> may be moved into position between the first arm <NUM> and second arm <NUM> of the first fastener <NUM>. Next, the set screw <NUM> may be inserted at least partially to secure the elongate member <NUM> into the head of the first fastener <NUM>. It may be desirable to only partially insert the set screw <NUM> to allow for the elongate member <NUM> to slide within the passageway <NUM> to enable the surgeon to position the first fastener <NUM> with respect to the second fastener <NUM> to maintain or re-establish proper spacing and alignment within the patient's spine. Once the desired position of the first fastener <NUM> and second fastener <NUM> is achieved, the set screw <NUM> may be fully inserted to secure the elongate member <NUM> in the desired position. Finally, the patient's incision may be closed.

Another single level fusion system <NUM> is shown in <FIG>. The single level fusion system <NUM> may include a first fastener assembly <NUM>, a second fastener assembly <NUM>, and an elongate member <NUM>. The first fastener assembly <NUM> may include a first fastener <NUM> and a set screw <NUM>. The first fastener <NUM> may include a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> and neck <NUM> may be of the type described above with reference to the shaft <NUM> and neck <NUM>, as described above, which will not be described again here for brevity sake. The head <NUM> may include a first arm <NUM>, a second arm <NUM>, and a passageway <NUM> extending between the first arm <NUM> and the second arm <NUM>. The first arm <NUM> and second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be curved or arced concavely to receive a correspondingly shaped elongate member <NUM>. The first arm <NUM> and second arm <NUM> may have, for example, a threaded portion <NUM> that extends along at least a portion of the interior surface of the first arm <NUM> and the second arm <NUM> from the top surface of the first and second arms <NUM>, <NUM> toward the base <NUM>. The first and second arms <NUM>, <NUM> may be similar to first and second arms <NUM>, <NUM>, however the first and second arms <NUM>, <NUM> are longer than the first and second arms <NUM>, <NUM>. The first and second arms <NUM>, <NUM> may also each include a break off line <NUM>. The break offline <NUM> provides a guide for shortening the first fastener <NUM> and the line <NUM> may be, for example, grooved or non-grooved. The longer arms <NUM>, <NUM> may provide for a larger head <NUM> to make it easier to start the insertion of the fastener <NUM> into the patient. However, it may not be desirable to have a longer head <NUM> remain in the patient, thus the line <NUM> provides for a break off point to shorten the arms <NUM>, <NUM> of the head <NUM>.

The set screw <NUM> may include a top surface <NUM>, a bottom surface <NUM>, a tool engagement opening <NUM>, and threads <NUM> of the type described above with references to set screw <NUM> and the top surface <NUM>, bottom surface <NUM>, tool engagement opening <NUM>, and threads <NUM>, respectively, which will not be described again here for brevity sake.

The second fastener assembly <NUM> may include a second fastener <NUM>, a set screw <NUM>, and a hinge member <NUM>. The second fastener <NUM> may have a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> and neck <NUM> may be of the type described above with reference to shaft <NUM> and neck <NUM> as described above and which will not be described again here for brevity sake. The head <NUM> may include a first arm <NUM>, a second arm <NUM>, and a passageway <NUM> extending between the first arm <NUM> and the second arm <NUM>. The first arm <NUM> and second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the bottom of the head <NUM> which couples to the shaft <NUM>. The first arm <NUM> and second arm <NUM> may, for example, each include an opening <NUM> extending from the interior surface to an exterior surface of the arms <NUM>, <NUM>. The opening <NUM> may be a tapered opening which, for example, is larger near the top of the head <NUM> and tapers as the opening <NUM> extends toward the shaft <NUM>. The at least one hinge member <NUM> may be positioned within the opening <NUM> in the first arm <NUM> and the second arm <NUM>. In addition, the hinge member <NUM> may also, for example, pass through the elongate member <NUM> to secure the elongate member <NUM> to the second fastener <NUM>.

The elongate member <NUM>, as shown in <FIG> and <FIG>, includes a first end <NUM> and a second end <NUM>. The elongate member <NUM> may be round at the first end <NUM> and rectangular at the second end <NUM>. The elongate member <NUM> may include an opening <NUM> near the second end <NUM> to receive the at least one hinge member <NUM>. The elongate member <NUM> may have a tapered portion <NUM> positioned between the round first end <NUM> and the rectangular second end <NUM>. The elongate member <NUM> may also have an end surface <NUM> with an opening <NUM>.

The system <NUM> may be implanted by first obtaining a first fastener assembly <NUM>, a second fastener assembly <NUM>, and an elongate member <NUM>. Then the elongate member <NUM> may be coupled to the second fastener assembly <NUM> by inserting the hinge member <NUM> into the openings <NUM> in the second fastener <NUM> to secure the elongate member <NUM> to the second fastener <NUM>. Next, the first fastener <NUM> and the second fastener assembly <NUM> with the attached elongate member <NUM> may each be inserted into the desired vertebrae. After insertion of the first fastener <NUM> and the second fastener <NUM>, the elongate member <NUM> may be moved into position between the first arm <NUM> and second arm <NUM> of the first fastener <NUM>. Next, a first set screw <NUM> may be inserted at least partially to secure the elongate member <NUM> into the head <NUM> of the first fastener <NUM>. The first set screw <NUM> may be inserted partially to allow for the surgeon to slide the elongate member <NUM> within the passageway <NUM> to position the first fastener <NUM> with respect to the second fastener <NUM> to maintain or re-establish proper spacing and alignment within the patient's spine. The second end <NUM> of the rod <NUM> may also be slid within the opening <NUM> to the desired position. Once the desired position is achieved, the first set screw <NUM> may be tightened to secure the elongate member <NUM> at the first end <NUM> and a second set screw <NUM> may be inserted into the head <NUM> of the second fastener <NUM> and tightened to secure the elongate member <NUM> at the second end <NUM>.

An alternative elongate member <NUM> is shown in <FIG>. The elongate member <NUM> includes a first end <NUM> and a second end <NUM>. The first end <NUM> of the elongate member <NUM> may have a polygon shape, such as a hexagon shape, and the second end <NUM> may have a rectangular shape. The elongate member <NUM> may include an opening <NUM> near the second end <NUM> to receive the at least one hinge member <NUM>. The elongate member <NUM> may have a tapered portion <NUM> positioned between the polygonal first end <NUM> and the rectangular second end <NUM>. The elongate member <NUM> may also have an end surface <NUM>. It is also contemplated that the elongate members disclosed herein may have multiple shapes including but not limited to square, rectangle, round, hexagonal, as well as any combination of these shapes depending on the fasteners that the elongate members are engaging.

A fastener member <NUM> is shown in <FIG>. The fastener member <NUM> includes a shaft <NUM>, a head <NUM>, and a neck portion <NUM> connecting the shaft <NUM> and the head <NUM>. The head <NUM> may include a first arm <NUM>, a second arm <NUM>, and a passageway <NUM> extending between the first arm <NUM> and second arm <NUM>. The first arm <NUM> and second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be, for example, planar or curved to correspond to the elongate member being received within the head <NUM> of the fastener member <NUM>. The first arm <NUM> and the second arm <NUM> may each have, for example, openings <NUM> extending from the interior surface to an exterior surface of the arms <NUM>, <NUM>. The openings <NUM> may be configured to receive, for example, a larger hinge member to provide for a stronger connection between the fastener member <NUM> and an elongate rod. The shaft <NUM> may be, for example, threaded along its entire length, threaded along only a portion of the its length, or non-threaded.

Referring now to <FIG>, an alternative embodiment of a single level fusion system <NUM> is shown. The system <NUM> may include a first fastener assembly <NUM>, a second fastener assembly <NUM>, and an elongate member <NUM>. The first fastener assembly <NUM> may include a first fastener <NUM> and a set screw <NUM>. The first fastener <NUM> may include a shaft <NUM> and a head <NUM> coupled to the top of the shaft <NUM>. The shaft <NUM> may be of the type described above with reference to shaft <NUM>. The head <NUM> may include a first arm <NUM>, a second arm <NUM>, and passageway <NUM> extending between the first arm <NUM> and the second arm <NUM>. The first arm <NUM> and second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the head <NUM>. The first arm <NUM> and the second arm <NUM> may have, for example, a threaded portion <NUM> that extends along at least a portion of the interior surface of the first arm <NUM> and the second arm <NUM> from the top surface of the first and second arms <NUM>, <NUM> toward the base <NUM>. The base <NUM> may include, for example, a protrusion <NUM> extending out from the base <NUM>. The protrusion <NUM> may alternatively be a ball or sphere to allow for the elongate member <NUM> to pivot with respect to the first fastener <NUM>. A ball or sphere protrusion <NUM> provides a bi-radius feature that allows for angulation of the rod in the sagittal plane.

As shown in <FIG>, the second fastener assembly <NUM> may include a second fastener <NUM> and a set screw <NUM>. The second fastener <NUM> may be of the type described above with reference to first fastener <NUM>. The shaft <NUM>, first arm <NUM>, second arm <NUM>, passageway <NUM>, base <NUM>, and protrusion <NUM> may be of the type described above with reference to shaft <NUM>, first arm <NUM>, second arm <NUM>, passageway <NUM>, base <NUM>, and protrusion <NUM>, as described above and which will not be described again here for brevity sake. The second fastener <NUM> may further include openings <NUM> extending from the exterior surface to an interior surface.

With continued reference to <FIG>, the set screws <NUM> may include a top surface <NUM>, a bottom surface <NUM>, and threads <NUM> positioned on the exterior surface of the set screws <NUM> and extending from the top surface <NUM> to the bottom surface <NUM>. The set screw <NUM> may also include a tool engagement opening <NUM> extending into the set screws <NUM> from the top surface <NUM> toward the bottom surface <NUM>. In addition, the bottom surface <NUM> of the set screws <NUM> may include a protrusion extending away from the set screw <NUM>.

The elongate member <NUM>, as shown in <FIG>, may include a first end <NUM> and a second end <NUM>. The elongate member <NUM> may include a first recess <NUM> extending from a top surface of the elongate member <NUM> toward the bottom surface and between the first end <NUM> and the second end <NUM>. In addition, the elongate member <NUM> may also include a second recess <NUM> extending from a bottom surface of the elongate member <NUM> toward the top surface and between the first end <NUM> and the second end <NUM>. The first recess <NUM> and second recess <NUM> of the elongate member <NUM> are sized and shaped to correspond to the protrusions <NUM>, <NUM>. When the elongate member <NUM> is positioned within the heads <NUM>, <NUM>, the recesses <NUM>, <NUM> mate with the protrusions <NUM>, <NUM>. In addition, the protrusions on the bottom surface <NUM> of the set screws <NUM> are sized and shaped to engage the recess <NUM> to allow the set screws <NUM> to securely couple the elongate member <NUM> to the first and second fasteners <NUM>, <NUM>.

A method (not claimed) for inserting the devices <NUM>, <NUM>, and <NUM> of <FIG> and <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM>, <NUM>, <NUM> into a first pedicle of a first vertebra. Then, the second fastener or pedicle screw <NUM>, <NUM>, <NUM> with the elongate member <NUM>, <NUM>, <NUM> is coupled to and in line with the longitudinal axis of the second fastener <NUM>, <NUM>, <NUM> may be inserted into an adjacent pedicle of a second vertebra. The fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be inserted using a guide wire or free hand. Next, the elongate member <NUM>, <NUM>, <NUM> is turned perpendicular to the fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and inserted in the desired position in the head <NUM>, <NUM>, <NUM> of the first fastener <NUM>, <NUM>, <NUM>. A locking mechanism, for example, set screws <NUM>, <NUM>, <NUM> may be inserted into the head <NUM>, <NUM>, <NUM> of the first fastener <NUM>, <NUM>, <NUM> and tightened down to secure the elongate member <NUM>, <NUM>, <NUM> to the first fastener <NUM>, <NUM>, <NUM>. A second locking mechanism, for example, set screws <NUM>, <NUM>, <NUM>, may also optionally be inserted into the head <NUM>, <NUM>, <NUM> of the second fastener <NUM>, <NUM>, <NUM>. Finally, the patient's incision may be closed.

According to the invention, a single level fusion system <NUM> is depicted in <FIG>. The single level fusion system <NUM> may include a first fastener assembly <NUM>, a second fastener assembly <NUM>, and an elongated member <NUM>. The first fastener assembly <NUM> may include a first fastener <NUM> and a fastener <NUM>. The first fastener <NUM> may be of the type described above with reference to first fastener <NUM>, which will not be described again here for brevity sake. The first fastener <NUM> may also include a threaded portion <NUM> on the exterior of head <NUM>.

As shown in <FIG>, the fastener <NUM> may include an exterior surface <NUM> and an interior surface <NUM>. The interior surface <NUM> may be threaded to secure the fastener <NUM> to the head <NUM> of the first fastener <NUM>. As seen in <FIG>, the fastener <NUM> may have a shape of, for example, a polygon, such as a hexagon.

The second fastener assembly <NUM>, as shown in <FIG>, may include a second fastener <NUM> and a hinge member <NUM>. The second fastener <NUM> may be of the type described above with reference to second fastener <NUM>, which will not be described again here for brevity sake. The second fastener <NUM> may also include a threaded portion <NUM> on the exterior of head <NUM>. The at least one hinge member <NUM> may be positioned within the openings <NUM> in the first and second arms <NUM>, <NUM>. The at least one hinge member <NUM> may also, for example, pass through the elongate member <NUM> to secure the elongate member <NUM> to the second fastener <NUM>.

A method (not claimed) for inserting the single level fusion system <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM> into a first pedicle of a first vertebra. Then the second fastener or pedicle screw <NUM> with the elongate member <NUM> coupled to and extended in line with the longitudinal axis of the second fastener <NUM> may be inserted into an adjacent pedicle of a second vertebra. The fasteners <NUM>, <NUM> may be inserted using a guide wire or free hand. Next the elongate member <NUM> is turned perpendicular to the fasteners <NUM>, <NUM> and inserted in the desired position in the head <NUM> of the first fastener <NUM>. A locking mechanism, for example, a nut <NUM> is then secured around the head <NUM> of the first fastener <NUM> and tightened down to secure the elongate member <NUM> to the first fastener <NUM>. A second locking mechanism, for example, a nut or set screw (not shown), may also optionally be secured to the head <NUM> of the second fastener <NUM> to secure the elongate member <NUM> to the second fastener <NUM>. Finally, the patient's incision may be closed.

The fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be cannulated through the center of the shaft along the long axis of the fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> and include an opening (not shown) to enable insertion over a guide wire, k-wire, pin, or the like to assist with insertion into the patient.

The elongate members <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may have a length. The length of the elongate members <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> will be selected based on the procedure being performed and whether compression or distraction is desired. For example, a rod that is longer than the position of the in situ fasteners will be used for distraction to move the engaged vertebrae apart and a rod that is shorter than the in situ position of the fasteners will be used for compression to pull the engaged vertebrae together. The length of elongate members <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may range from, for example, approximately <NUM> to <NUM> and more specifically approximately <NUM> to <NUM>. The elongate members <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be straight or curved along the longitudinal axis.

Referring now to <FIG>, a single level fusion system <NUM> is shown. The single level fusion system <NUM> may include a first fastener <NUM>, a second fastener <NUM>, an elongate member <NUM>, and a set screw <NUM>. The first fastener <NUM> may include a shaft <NUM> and an attachment portion <NUM> with an opening (not shown). The shaft <NUM> may be, for example, threaded from the attachment portion <NUM> to the tip or along only a portion of the length from the attachment portion <NUM> to the tip.

The second fastener <NUM>, as shown in <FIG>, may include a shaft <NUM>, an attachment portion <NUM>, and a connector portion <NUM> that couples the shaft <NUM> to the attachment portion <NUM> at approximately a <NUM>° angle. The shaft <NUM> may be, for example, threaded from the connector portion <NUM> to the tip or along only a portion of the length from the connector portion <NUM> to the tip. The attachment portion <NUM> and connector portion <NUM> may be round.

The elongate member <NUM> may have a first end <NUM> and a second end <NUM>, as shown in <FIG>. The elongate member <NUM> may also include an attachment groove <NUM> in the first end <NUM>. The first end <NUM> may also include at least one opening <NUM> extending from the exterior surface of the elongate member <NUM> into the attachment groove <NUM>. The elongate member <NUM> may also have a first opening <NUM> extending through the elongate member <NUM> from a first side to a second side for receiving the attachment portion <NUM> of the second fastener <NUM>. The first opening <NUM> may have, for example, an oval shape. In addition, the elongate member <NUM> may include a second opening <NUM> extending from a top surface into the first opening <NUM>. The second opening <NUM> may include, for example, a plurality of overlapping screw holes forming a scalloped shaped second opening <NUM>. The second opening <NUM> may include threads <NUM>.

The single level fusion system <NUM> may also include a set screw <NUM>. As seen in <FIG>, the set screw <NUM> may include a top surface <NUM> and a bottom surface <NUM>. The set screw <NUM> may also include a tool engagement opening <NUM> extending into the set screw <NUM> from the top surface <NUM> toward the bottom surface <NUM>. In addition, the set screw <NUM> may include threads <NUM> on the exterior surface extending from the top surface <NUM> to the bottom surface <NUM>.

With continued reference to <FIG>, the single level fusion system <NUM> may be assembled by inserting the attachment portion <NUM> of the first fastener <NUM> into the attachment groove <NUM> of the elongate member <NUM> and aligning the opening (not shown) in the attachment portion <NUM> with the openings <NUM> in the elongate member <NUM>. Next, a hinge member <NUM> may be inserted through an opening <NUM> in the elongate member <NUM> and the opening (not shown) in the attachment portion <NUM> to moveably couple the first fastener <NUM> to the elongate member <NUM>. In use, the first fastener <NUM> and coupled elongate member <NUM> may be inserted into a first vertebra in a patient and the second fastener <NUM> may be inserted into a second adjacent vertebra. Then, the attachment portion <NUM> may be inserted into the first opening <NUM>. The attachment portion <NUM> may be translated within the first opening <NUM> until a desired position is achieved, then the set screw <NUM> may be inserted into the second opening <NUM> to secure the attachment portion <NUM> to the elongate member <NUM>. When the set screw <NUM> is inserted into the second opening <NUM>, the threads <NUM> of the set screw <NUM> engage one set of threads <NUM> in the second opening <NUM>.

The fasteners <NUM>, <NUM> and the elongate member <NUM> may be cannulated through the center of the shafts along a longitudinal axis to enable insertion over a guide wire, k-wire, pin, or the like to assist with insertion into the patient.

A method (not claimed) for inserting the single level fusion system <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM> with the elongate member <NUM> extended in line with the longitudinal axis of the fastener <NUM> into a first pedicle of a first vertebra. A second fastener or pedicle screw <NUM> may then be inserted into an adjacent second pedicle of a second vertebra. The fasteners <NUM>, <NUM> may be inserted using a guide wire if the fasteners <NUM>, <NUM> are cannulated or free hand. Then the elongate member <NUM> may be turned perpendicular to the fastener <NUM>. Next the attachment portion <NUM> of the second fastener <NUM> may be turned into the slot <NUM> of the elongate member <NUM>. A locking mechanism, for example, a set screw <NUM> may be inserted into a desired position in the second opening <NUM> of the elongate member <NUM> and tightened down to secure the second fastener <NUM> to the elongate members <NUM>. Finally, the patient's incision may be closed.

Another single level fusion system <NUM> is shown in <FIG> and includes a first fastener <NUM>, a second fastener assembly <NUM>, and an elongate member <NUM>. The first fastener <NUM> may include a shaft <NUM> and an attachment portion <NUM> with an opening (not shown). The shaft <NUM> may be, for example, threaded from the attachment portion <NUM> to the tip or along only a portion of the length from the attachment portion <NUM> to the tip.

The second fastener assembly <NUM>, as shown in <FIG>, includes a second fastener <NUM> and a translating rod <NUM>. The second fastener <NUM> may include a shaft <NUM> and an attachment portion <NUM> with an opening (not shown). The shaft <NUM> may be, for example, threaded from the attachment portion <NUM> to the tip or along only a portion of the length from the attachment portion <NUM> to the tip. The translating rod <NUM> may include an attachment groove <NUM> in the second end of the translating rod <NUM>. The second end may also include at least one opening <NUM> extending from the exterior surface of the translating rod <NUM> into the attachment groove <NUM>. The second fastener <NUM> may be attached to the translating rod <NUM> by aligning the opening (not shown) in the second fastener <NUM> with the at least one opening <NUM> in the translating rod <NUM>. Then, a hinge member <NUM> may be inserted and secured to couple the second fastener <NUM> to the translating rod <NUM>.

The elongate member <NUM> may have a first end and a second end, as shown in <FIG>. The elongate member <NUM> may also include an attachment groove <NUM> in the first end. The second end may include a first opening <NUM> extending from the second end of the elongate member <NUM> toward the first end through the interior of the elongate member <NUM>. The first opening <NUM> may be sized to receive the translating rod <NUM> of the second fastener assembly <NUM>. The first opening <NUM> may have, for example, a round shape or other shape to match the shape of the translating rod <NUM>. In addition, the elongate member <NUM> may include a second opening <NUM> extending from a top surface into the first opening <NUM>. The second opening <NUM> may include, for example, a plurality of overlapping screw holes forming a scalloped shaped second opening <NUM>. The second opening <NUM> may include threads <NUM> in each of the overlapping screw holes.

With continued reference to <FIG>, the single level fusion system <NUM> may be assembled by inserting the attachment portion <NUM> of the first fastener <NUM> into the attachment groove <NUM> of the elongate member <NUM> and aligning the opening (not shown) in the attachment portion <NUM> with the openings <NUM> in the elongate member <NUM>. Next, a hinge member <NUM> may be inserted through the opening <NUM> in the elongate member <NUM> and the opening (not shown) in the attachment portion <NUM> to moveably couple the first fastener <NUM> to the elongate member <NUM>. The second fastener <NUM> may be coupled to the translating rod <NUM> to form the second fastener assembly <NUM>. The second fastener <NUM> may be coupled to the translating rod <NUM> by aligning the opening (not shown) in the attachment portion <NUM> of the second fastener <NUM> with the at least one opening <NUM> in the elongate member <NUM>. In use, the first fastener <NUM> and coupled elongate member <NUM> may be inserted into a first vertebra in a patient and the second fastener assembly <NUM> may be inserted into a second adjacent vertebra. Then the translating rod <NUM> may be inserted into the first opening <NUM>. The translating rod <NUM> may be slid within the first opening <NUM> until a desired position is achieved. Then, the set screw <NUM> may be inserted into the second opening <NUM> to secure the translating rod <NUM> of the second fastener assembly <NUM> to the elongate member <NUM>. When the set screw <NUM> is inserted into the second opening <NUM>, the threads <NUM> of the set screw <NUM> engage one set of threads <NUM> in the second opening <NUM>.

As illustrated in <FIG>, the first fastener <NUM> may rotate with respect to the elongate member <NUM>, for example, almost <NUM>° being restrained only by contact with the elongate member <NUM>. The second fastener <NUM> may also rotate with respect to the translating rod <NUM>, for almost <NUM>° and again only be restrained by contact with the translating rod <NUM>. The fasteners <NUM>, <NUM> each have a variable range of motion and the angle of the fasteners <NUM>, <NUM> after implantation will generally be determined by the patient's anatomy. In addition, as shown in <FIG>, the second fastener assembly <NUM> may translate into and out of the elongate member <NUM>. Further, as shown in <FIG>, the second fastener assembly <NUM> may rotate approximately <NUM>° within the opening <NUM> of the elongate member <NUM>.

The fasteners <NUM>, <NUM>, translating rod <NUM>, and the elongate member <NUM> may be cannulated through the center of the shafts along a longitudinal axis to enable insertion over a guide wire, k-wire, pin, or the like to assist with insertion into the patient.

A method (not claimed) for inserting the single level fusion system <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM> with the coupled elongate member <NUM> extended in line with the longitudinal axis of the fastener <NUM> into a first pedicle of a first vertebra. A second fastener or pedicle screw <NUM> with the coupled translating rod <NUM> extended in line with the longitudinal axis of the fastener <NUM> may then be inserted into an adjacent second pedicle of a second vertebra. The fasteners <NUM>, <NUM> may be inserted using a guide wire if the fasteners <NUM>, <NUM>, translating rod <NUM>, and elongate member <NUM> are cannulated or free hand. Then the elongate member <NUM> may be turned perpendicular to the fastener <NUM> and the translating rod <NUM> may be turned perpendicular to the fastener <NUM>. Next, the translating rod <NUM> may be inserted into the first opening <NUM> of the elongate member <NUM>. A locking mechanism, for example, a set screw <NUM> may be inserted into a desired position in the second opening <NUM> of the elongate member <NUM> and tightened down to secure the translating rod <NUM> of the second fastener assembly <NUM> to the elongate member <NUM>. Finally, the patient's incision may be closed.

<FIG> show single level fusion systems <NUM>, <NUM>. The single level fusion system <NUM>, as shown in <FIG>, may include a first fastener assembly <NUM> and a second fastener assembly <NUM>. The first fastener assembly <NUM> may include a shaft <NUM>, an elongate member <NUM>, and a neck <NUM> for securing the shaft <NUM> to the elongate member <NUM>. The shaft <NUM> may, for example, be attached perpendicular to the elongate member <NUM> and the shaft <NUM> may be fixed or rotatable with respect to the elongate member <NUM>. The elongate member <NUM> may include a body with the shaft <NUM> attached at a first end and a first opening <NUM> at the second end for receiving the second fastener assembly <NUM>. The first opening <NUM> may extend from the second end into the body of the elongate member <NUM> toward the first end. The elongate member <NUM> may also include a second opening <NUM> extending from the top surface into the first opening <NUM>. The opening <NUM> may be, for example, threaded. The second fastener assembly <NUM> may include a second fastener <NUM> and a threaded rod <NUM>. The threaded rod <NUM> may include a non-threaded portion <NUM> at a second end. The portion <NUM> may include a first opening <NUM> extending entirely through the threaded rod <NUM> perpendicular to the longitudinal axis of the threaded rod <NUM>. The threaded rod <NUM> may also include a second opening <NUM> extending from a side of the threaded rod <NUM> through to the first opening <NUM>. The first opening <NUM> and second opening <NUM> may be positioned relatively perpendicular. The second opening <NUM> may be configured to receive a locking mechanism <NUM>. The second opening <NUM> may be, for example, threaded to receive the locking mechanism <NUM>. The second fastener <NUM> may have a first end <NUM> and a second end which may be pointed. The second fastener <NUM> may be attached to the threaded rod <NUM> by inserting the first end <NUM> of the second fastener <NUM> into the opening <NUM> in the threaded rod <NUM>. Once the second fastener <NUM> is in a desired position with respect to the threaded rod <NUM>, then a locking mechanism <NUM> may be inserted to secure the second fastener <NUM> to the threaded rod <NUM>. The single level fusion system <NUM> may be formed by screwing the threaded rod <NUM> of the second fastener assembly <NUM> into the opening <NUM> in the elongate member <NUM> of the first fastener assembly <NUM>.

The single level fusion system <NUM>, as shown in <FIG>, may include a first fastener <NUM> and a second fastener assembly <NUM>. The first fastener assembly <NUM> may include a shaft <NUM>, an elongate member <NUM>, and a neck <NUM> for securing the shaft <NUM> to the elongate member <NUM>. The shaft <NUM> may be, for example, attached angled to the elongate member <NUM> and the shaft <NUM> may be fixed or rotatable with respect to the elongate member <NUM>. The elongate member <NUM> may include a body with the shaft <NUM> attached at a first end and a first opening <NUM> at the second end for receiving the second fastener assembly <NUM>. The first opening <NUM> may extend from the second end into the body of the elongate member <NUM> toward the first end. The first opening <NUM> may be, for example, threaded. The elongate member <NUM> may also include a second opening <NUM> extending from the top surface into the first opening <NUM>. The second fastener assembly <NUM> is of the type described above with reference to <FIG>. The single level fusion system <NUM> may be formed by screwing the threaded rod <NUM> of the second fastener assembly <NUM> into the opening <NUM> in the elongate member <NUM> of the first fastener assembly <NUM>.

The locking mechanisms <NUM> may be, for example, set screws of the type described above with reference to set screw <NUM>, which will not be described again here for brevity sake. Alternative locking mechanisms <NUM> are also contemplated to secure the portions of the single level fusion systems <NUM>, <NUM> together. The set screws <NUM>, as shown in <FIG>, include a top surface <NUM> and a tool engagement opening <NUM>.

The shaft <NUM> and fastener <NUM> and the elongate member <NUM> may be cannulated through the center of the shafts along a longitudinal axis to enable insertion over a guide wire, k-wire, pin, or the like to assist with insertion into the patient.

A method (not claimed) for inserting the single level fusion systems <NUM>, <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert the first fastener <NUM>, <NUM> with the elongate member <NUM>, <NUM> extended in line with the longitudinal axis of the fastener <NUM>, <NUM> into a first pedicle of a first vertebra. Then the threaded rod <NUM> may be inserted or screwed into the first opening <NUM>, <NUM> of the elongate member <NUM>, <NUM>. The threaded rod <NUM> may be screwed to a desired position with respect to the elongate member <NUM>, <NUM> and the length of the threaded rod <NUM> extending out from the elongate member <NUM>, <NUM> will determine the amount of compression or distraction of the two vertebrae. Next the second fastener <NUM> is inserted through the first opening <NUM> on the distal end of the threaded rod <NUM> and into a second pedicle in a second adjacent vertebra. The fasteners <NUM>, <NUM> may be inserted using a guide wire if the fasteners are cannulated or free hand. The second fastener <NUM> may be secured to the threaded rod <NUM> by inserting a locking mechanism, for example, a set screw <NUM> into the second opening <NUM> in the threaded rod <NUM>. Then a locking mechanism, for example, a cap or set screw <NUM>, may be inserted into the second opening <NUM>, <NUM> and tightened down to secure the threaded rod <NUM> to the elongate member <NUM>, <NUM>. Finally, the patient's incision may be closed.

A single level fusion device <NUM> is shown in <FIG>. The single level fusion device <NUM> may include a first fastener <NUM> and a second fastener <NUM>. The first fastener <NUM> may include a shaft <NUM>, a head <NUM>, and a neck <NUM> extending out of the head <NUM> for coupling the shaft <NUM> to the head <NUM>. The shaft <NUM> may include a threaded portion and an attachment portion <NUM>. The head <NUM> may include a first opening <NUM> and a second opening <NUM>. The first opening <NUM> may extend through the head <NUM> and into the second opening <NUM>. The first opening <NUM> may be threaded to receive a set screw <NUM>. The neck <NUM> may include two arms <NUM>. The neck <NUM> may also include an opening (not shown) to receive a hinge member <NUM>. The attachment portion <NUM> of the shaft <NUM> may be positioned between the two arms <NUM> of the neck <NUM> aligning an opening (not shown) in the attachment portion <NUM> with the opening (not shown) in the neck <NUM> and the hinge member <NUM> inserted into the openings to moveably couple the head <NUM> to the shaft <NUM>. The hinge member <NUM> allows for the head <NUM> to pivot or rotate relative to the shaft <NUM>. The second fastener <NUM>, as shown in <FIG>, may include a shaft <NUM> and an attachment portion <NUM> with a protrusion <NUM> extending out from the attachment portion <NUM>. The protrusion <NUM> may have a round or ball shape.

As shown in <FIG> and <FIG> and more specifically in <FIG> and <FIG>, the set screw <NUM> may include a top surface <NUM> and a bottom surface <NUM>. The set screw <NUM> may also include a tool engagement opening <NUM> extending into the set screw <NUM> from the top surface <NUM> toward the bottom surface <NUM>. In addition, the set screw <NUM> may include threads <NUM> on the exterior surface extending from the top surface <NUM> to the bottom surface <NUM>. It is also contemplated that the set screw <NUM> may be replaced with a ratcheting mechanism (not shown) that allows for the second fastener <NUM> to pass into the opening <NUM> in the first fastener <NUM> in a first direction, but prevents the second fastener <NUM> from moving through the opening <NUM> in a second reverse direction.

To assemble the single level fusion device <NUM>, the attachment portion <NUM> of the second fastener <NUM> may be inserted into the opening <NUM> of the head <NUM> of the first fastener <NUM>. The attachment portion <NUM> may be inserted until the protrusion <NUM> is positioned within the opening <NUM>. Once inserted, the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM>. Then, a set screw <NUM> may be inserted into the first opening <NUM> to secure the protrusion <NUM> within the opening <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>. Additional rotation of the first fastener <NUM> with respect to the second fastener <NUM> may then be achieved for insertion into a patient by rotating the first and second fasteners <NUM>, <NUM> at the hinge member <NUM>.

<FIG> illustrate another single level fusion device <NUM>. The single level fusion device <NUM> includes a first fastener <NUM> and a second fastener <NUM>. The first fastener <NUM> may include a shaft <NUM>, a neck <NUM> attached to the shaft <NUM> at a connection point <NUM>, and a head <NUM> coupled to the neck <NUM> at a position opposite the shaft <NUM>. The neck <NUM> may be tapered from the head <NUM> to the shaft <NUM>. In addition, the neck <NUM> may be fixed. The shaft <NUM> may be threaded along the entire length or only along a portion of the length. The head <NUM> may include a first opening <NUM> and a second opening <NUM>. The first opening <NUM> may extend from the exterior surface of the head <NUM> into the second opening <NUM>. The first opening <NUM> may be threaded for receiving a set screw <NUM>. The second opening <NUM> may extend entirely through the head <NUM>. The second fastener <NUM> and the set screw <NUM> are described in greater detail above and will not be described again here for brevity sake. It is also contemplated that the set screw <NUM> may be replaced with a ratcheting mechanism (not shown) that allows for the second fastener <NUM> to pass into the opening <NUM> in the first fastener <NUM> in a first direction but prevents the second fastener <NUM> from moving through the opening <NUM> in a second reverse direction.

To assemble the single level fusion device <NUM>, the attachment portion <NUM> of the second fastener <NUM> may be inserted into the opening <NUM> of the head <NUM> of the first fastener <NUM>. The attachment portion <NUM> may be inserted until the protrusion <NUM> is positioned within the opening <NUM>. Once inserted the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM>. Then, a set screw <NUM> may be inserted into the first opening <NUM> to secure the protrusion <NUM> within the opening <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>.

Referring now to <FIG>, a single level fusion device <NUM> may include a first fastener <NUM> and a second fastener <NUM>. The first fastener <NUM> may include a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> may be threaded, for example, along its entire length or along only a portion of the length. The head <NUM> may include a first arm <NUM>, a second arm <NUM>, and a passageway <NUM> extending between the first arm <NUM> and the second arm <NUM>. The first arm <NUM> and second arm <NUM> each have an interior surface formed by the passageway <NUM>. The passageway <NUM> also forms a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be, for example, curved. The first arm <NUM> and second arm <NUM> may be shaped, for example, curved, to match the shape of the attachment portion <NUM> of the second fastener <NUM>. In addition, the first fastener <NUM> may include an opening <NUM> with threads <NUM> for receiving a set screw <NUM>. The second fastener <NUM> and set screw <NUM> are described in greater detail above and will not be described again here for brevity sake.

To assemble the single level fusion device <NUM>, the attachment portion <NUM> of the second fastener <NUM> may be inserted into the passageway <NUM> of the head <NUM> of the first fastener <NUM>. The attachment portion <NUM> may be inserted until the protrusion <NUM> is positioned within the passageway <NUM>. Once inserted, the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM>. Then a set screw <NUM> may be inserted into the opening <NUM> to secure the protrusion <NUM> within the passageway <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>.

An alternative embodiment of a single level fusion device <NUM> is shown in <FIG> and includes a first fastener <NUM>, a second fastener <NUM>, and a set screw <NUM>. The first fastener <NUM> may include a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> may be threaded, for example, along its entire length or along only a portion of the length. The head <NUM> may include a first arm <NUM>, a second arm <NUM> opposite the first arm <NUM> forming a passageway. The first arm <NUM> and second arm <NUM> may be connected by a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be, for example, curved. The first arm <NUM> and second arm <NUM> may be shaped, for example, curved, to match the shape of the attachment portion <NUM> of the second fastener <NUM>. In addition, the first arm <NUM> and second arm <NUM> may include threads <NUM> on the interior surface extending from the top surface of the head <NUM> down toward the base <NUM>.

The second fastener <NUM>, as shown in <FIG>, may include a shaft <NUM> and an attachment portion <NUM> with a protrusion <NUM> extending out from the attachment portion <NUM>. The protrusion <NUM> may have a round or ball shape. The protrusion <NUM> may include a plurality of openings <NUM> to make the protrusion <NUM> deformable. The openings <NUM> create a collapsible or crushable construct <NUM> that crimps down onto the threads <NUM> in the head <NUM> of the first fastener <NUM> to secure the second fastener <NUM> to the first fastener <NUM> as the set screw <NUM> is inserted.

To assemble the single level fusion device <NUM>, the attachment portion <NUM> of the second fastener <NUM> may be inserted into the head <NUM> of the first fastener <NUM>. The attachment portion <NUM> may be inserted until the protrusion <NUM> is positioned between the first arm <NUM> and the second arm <NUM>. Once inserted the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM> to reach a desired position. Then a set screw <NUM> may be inserted into the head <NUM> between the first arm <NUM> and the second arm <NUM> to secure the protrusion <NUM> within the head <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>. The plurality of openings <NUM> in the protrusion <NUM> allow the protrusion <NUM> to be deformed when a set screw <NUM> is inserted.

<FIG> illustrates a single level fusion device <NUM> and includes a first fastener <NUM>, a second fastener <NUM>, and a set screw <NUM>. The first fastener <NUM> may include a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> may be threaded, for example, along its entire length or along only a portion of the length. The head <NUM> may include a first arm <NUM>, a second arm <NUM> opposite the first arm <NUM> forming a passageway. The length of the first arm <NUM> and second arm <NUM> may be longer as shown although the arms <NUM>, <NUM> may be longer or shorter than the length of the arms <NUM>, <NUM> shown. The first arm <NUM> and second arm <NUM> may be connected by a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be, for example, curved. The first arm <NUM> and second arm <NUM> may be shaped, for example, curved, to match the shape of the attachment portion <NUM> of the second fastener <NUM>, specifically to match the protrusion <NUM>. In addition, the first arm <NUM> and second arm <NUM> may include threads <NUM> on the interior surface extending from the top surface of the head <NUM> down toward the base <NUM>. The second fastener <NUM> and set screw <NUM> are described in greater detail above and will not be described again here for brevity sake.

To assemble the single level fusion device <NUM>, the attachment portion <NUM> of the second fastener <NUM> may be inserted into the head <NUM> of the first fastener <NUM>. The attachment portion <NUM> may be inserted until the protrusion <NUM> is positioned between the first arm <NUM> and the second arm <NUM>. Once inserted the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM>. Then a set screw <NUM> may be inserted into the head <NUM> between the first arm <NUM> and the second arm <NUM> to secure the protrusion <NUM> within the head <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>.

The fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be cannulated through the center of the shafts along a longitudinal axis to enable insertion over a guide wire, k-wire, pin, or the like to assist with insertion into the patient.

A method (not claimed) for inserting the single level fusion system <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next, the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM>, <NUM>, <NUM>, <NUM>, <NUM> into a first pedicle of a first vertebra. Also using an image guidance or fluoroscopy device, a second fastener or pedicle screw <NUM>, <NUM> may then be inserted through the head <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the first fastener <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and into an adjacent second pedicle of a second vertebra. The first fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may have a variable angled neck <NUM> or a fixed neck <NUM>, <NUM>, <NUM>, <NUM>. The fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be inserted using a guide wire if they are cannulated or free hand. A locking mechanism, for example, a set screw <NUM> may be inserted into the head <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the first fastener <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and tightened down to secure the second fastener <NUM>, <NUM> to the first fastener <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The locking mechanism may be inserted, for example, from the side of the heads of fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, as shown in <FIG>, or from the top of the heads of the fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, as shown in <FIG>. Finally, the patient's incision may be closed.

A fastener <NUM> is shown in <FIG>. The fastener <NUM> includes a threaded shaft <NUM>, a neck <NUM>, and a head <NUM>. The threaded shaft <NUM> is coupled to the neck <NUM> at connection <NUM> which angles the threaded shaft <NUM> with respect to the neck <NUM>. The head <NUM> is coupled to the neck <NUM> at connection <NUM>.

Referring now to <FIG>, a fastener assembly <NUM> is shown and includes a fastener <NUM> and a coupling mechanism <NUM>. The fastener <NUM> may include a shaft <NUM>, a neck <NUM>, and a head <NUM>. The neck <NUM> is positioned between and couples the head <NUM> to the shaft <NUM>. The coupling mechanism <NUM> may include a body <NUM> with a first opening <NUM> and a second opening <NUM>. The body <NUM> may have, for example, a generally rectangular or oval shape. The first opening <NUM> may be positioned relatively perpendicular to the second opening <NUM>. The first opening <NUM> may receive the head <NUM> of the fastener <NUM> and the second opening <NUM> may receive an end of a second fastener, for example, second fastener <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>.

Another fastener <NUM> is shown in <FIG>. The fastener <NUM> may include a shaft <NUM>, a neck <NUM>, and a head <NUM>. The neck <NUM> is positioned between the shaft <NUM> and the head <NUM> and may the neck <NUM> may extend out of the shaft <NUM> at either a straight or angled position to arrange the head <NUM> either in line or angled with respect to the shaft <NUM>. The head <NUM> may include a first arm <NUM>, a second arm <NUM> positioned opposite the first arm <NUM>, and a base <NUM> connecting the first arm <NUM> and the second arm <NUM>. The base <NUM> may have an interior surface that is, for example, planar or curved in either a concave or convex shape. The interior surface of the first arm <NUM> and the second arm <NUM> may each include a threaded portion <NUM> for receiving a set screw, such as, set screw <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

Referring now to <FIG>, a single level fusion device <NUM> is shown. The single level fusion device <NUM> may include a first fastener <NUM>, a second fastener <NUM>, and a screw <NUM>. The first fastener <NUM> may include a shaft <NUM>, a head <NUM>, and a neck <NUM> connecting the shaft <NUM> and the head <NUM>. The shaft <NUM> may be threaded, for example, along its entire length or along only a portion of the length. The head <NUM> may include a first arm <NUM>, a second arm <NUM> opposite the first arm <NUM> forming a passageway. The first arm <NUM> and second arm <NUM> may be connected by a base <NUM> near the bottom of the head <NUM>. The base <NUM> may be, for example, curved. The first arm <NUM> and second arm <NUM> may be shaped, for example, curved, to match the shape of the protrusion <NUM> of the attachment portion <NUM> of the second fastener <NUM>. In addition, the first arm <NUM> and second arm <NUM> may have a knurled or roughened surface <NUM> on the interior surface extending from the top surface of the head <NUM> down toward the base <NUM>. It is also contemplated that in an alternative embodiment, the first fastener <NUM> could be a fastener <NUM> or <NUM> including a head <NUM> or1080.

The second fastener <NUM>, as shown in <FIG>, may include a shaft <NUM> and an attachment portion <NUM> with a protrusion <NUM> extending out from the attachment portion <NUM>. The protrusion <NUM> may have a round or ball shape. The attachment portion <NUM> may include openings <NUM> extending from a first end of the second fastener <NUM> into the protrusion <NUM> to make the protrusion <NUM> deformable. The screw <NUM> includes a head <NUM> and a shaft <NUM> extending out of the bottom of the head <NUM>. The shaft <NUM> of the screw <NUM> may be sized and shaped to be inserted into one of the openings <NUM> in the attachment portion <NUM> and protrusion <NUM> to expand the protrusion <NUM> to couple the second fastener <NUM> to the first fastener <NUM>.

To assemble the single level fusion device <NUM>, the attachment portion <NUM> of the second fastener <NUM> may be inserted into the head <NUM> of the first fastener <NUM>. The attachment portion <NUM> may be inserted until the protrusion <NUM> is positioned between the first arm <NUM> and the second arm <NUM>. Once inserted the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM>. Then, the screw <NUM> may be inserted into the attachment portion <NUM> and protrusion <NUM> to secure the protrusion <NUM> within the head <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>. The plurality of openings <NUM> in the protrusion <NUM> allow the protrusion <NUM> to be deformed when a screw <NUM> is inserted.

The fasteners <NUM>, <NUM> may be cannulated through the center of the shafts along a longitudinal axis of the fasteners <NUM>, <NUM> to enable insertion over a guide wire, k-wire, pin, or the like to assist with insertion into the patient.

A method (not claimed) for inserting the single level fusion system <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next, the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM> into a first pedicle of a first vertebra. The image guidance or fluoroscopy device may also be used to insert a second fastener or pedicle screw <NUM> through the head <NUM> of the first fastener <NUM> and into an adjacent pedicle of a second vertebra. The first fasteners <NUM> may have a variable angled neck or a fixed neck. The fasteners <NUM>, <NUM> may be inserted using a guide wire if the fasteners <NUM>, <NUM> are cannulated or free hand. A locking mechanism, for example, a screw <NUM> may be used to secure the first fastener <NUM> and second fastener <NUM>. The screw <NUM> may be inserted into the end of the attachment portion <NUM> of the second fastener <NUM> to expand the protrusion <NUM> of the second fastener <NUM> and secure the second fastener <NUM> within the head <NUM> of the first fastener <NUM>. Finally, the patient's incision may be closed.

As shown in <FIG>, the method of inserting the single level fusion system <NUM> may further include inserting the first fastener <NUM> into a first vertebra <NUM>. The second fastener <NUM> may then be inserted through the head <NUM> of the first fastener <NUM> and into the second vertebra <NUM>. Once the protrusion <NUM> of the second fastener <NUM> is positioned in the head <NUM> of the first fastener <NUM> and the first fastener <NUM> and second fastener <NUM> are in the desired position within the first and second vertebrae <NUM>, <NUM>, then the screw <NUM> may be inserted. The screw <NUM> may be inserted into the openings <NUM> in the second fastener <NUM> to expand the protrusion <NUM> in the head <NUM> to secure the second fastener <NUM> to the first fastener <NUM>.

As shown in <FIG>, the method of inserting the single level fusion system <NUM> may alternatively include inserting the first fastener <NUM> into the second vertebra <NUM>. The second fastener <NUM> may then be inserted through the head <NUM> of the first fastener <NUM> and into the first vertebra <NUM>. Once the protrusion <NUM> of the second fastener <NUM> is positioned in the head <NUM> of the first fastener <NUM> and the first fastener <NUM> and second fastener <NUM> are in the desired position within the second and first vertebrae <NUM>, <NUM>, respectively, then the screw <NUM> may be inserted. The screw <NUM> may be inserted into the openings <NUM> in the second fastener <NUM> to expand the protrusion <NUM> in the head <NUM> to secure the second fastener <NUM> to the first fastener <NUM>.

A single level fusion device <NUM> is shown in <FIG>. The single level fusion device <NUM> may include a first fastener <NUM>, a second fastener <NUM>, a securement member <NUM>, and a set screw <NUM>. The first fastener <NUM> and the set screw <NUM> are describe above in greater detail and will not be described again here for brevity sake. The second fastener <NUM> may include a shaft <NUM>, an attachment portion <NUM> with a protrusion <NUM> extending out from the attachment portion <NUM>, and an end portion <NUM> extending out from the protrusion <NUM>. The protrusion <NUM> may have a round or ball shape. The protrusion <NUM> may include a plurality of openings <NUM> to make the protrusion <NUM> deformable. The securement member <NUM> may include a base <NUM> with a top surface <NUM> and four legs <NUM> extending down from the top surface <NUM>. The top surface <NUM> may also include an opening <NUM> extending through the top surface for receiving the protrusion <NUM>.

To assemble the single level fusion device <NUM>, the protrusion <NUM> of the second fastener <NUM> may be inserted into the head <NUM> of the first fastener <NUM>. The protrusion <NUM> may be positioned between the first arm <NUM> and the second arm <NUM>. Once inserted the second fastener <NUM> may be rotated slightly within the head <NUM> of the first fastener <NUM> until the desired position is achieved. Then, the securement member <NUM> may be inserted into the head <NUM> between the arms <NUM>, <NUM> and positioned over the protrusion <NUM>. Next, a set screw <NUM> may be inserted into the head <NUM> between the first arm <NUM> and the second arm <NUM> to secure the securement member <NUM> and the protrusion <NUM> within the head <NUM> of the first fastener <NUM> to secure the first fastener <NUM> in a desired position with respect to the second fastener <NUM>. The plurality of openings <NUM> in the protrusion <NUM> allow the protrusion <NUM> to be deformed when a set screw <NUM> is inserted.

A method (not claimed) for inserting the single level fusion system <NUM> of <FIG> into a patient may include cutting a small incision in the patient, for example, a <NUM> incision. Next, the fascia is cut and muscles are split in line of the fibers to expose the patient's vertebrae. Once the vertebrae are exposed, an image guidance or fluoroscopy device may be used to insert a first fastener or pedicle screw <NUM> into a first pedicle of a first vertebra. The image guidance or fluoroscopy device may also be used to insert a second fastener or pedicle screw <NUM> through the head <NUM> of the first fastener <NUM> and into an adjacent pedicle of a second vertebra. The first fastener <NUM> may have a variable angled neck or a fixed neck. The fasteners <NUM>, <NUM> may be inserted using a guide wire if the fasteners <NUM>, <NUM> are cannulated or free hand. A locking mechanism, for example, a set screw <NUM> may be used to secure the first fastener <NUM> and second fastener <NUM>. The locking mechanism may also optionally include a securement member <NUM> which may be inserted over the second fastener <NUM> before inserting the set screw <NUM>. The set screw <NUM> may be inserted into the head <NUM> of the first fastener <NUM> to secure the protrusion <NUM> of the second fastener <NUM>. Finally, the patient's incision may be closed.

Referring now to <FIG>, a rodless single level fusion system <NUM> is shown. The system <NUM> may include a first fastener or screw <NUM>, a second fastener or screw <NUM>, and a connector <NUM>. The connector <NUM> may be configured to receive the first fastener <NUM> and the second fastener <NUM>. The first fastener <NUM> may be, for example, a screw, straight wire, or curved wire. The first fastener <NUM> may include a first portion <NUM> and a second portion <NUM>. The first portion <NUM> may have a, for example, hexagonal shape and may extend from a first end of the screw <NUM> to a position near the midpoint. The second portion <NUM> may be, for example, threaded and may extend from a second end of the screw <NUM> to a position near the midpoint. The second fastener <NUM> may be, for example, a screw, straight wire, or curved wire. The second fastener <NUM> may include a first portion <NUM> and a second portion <NUM>. The first portion <NUM> may have a, for example, hexagonal shape and may extend from a first end of the screw <NUM> to a position near the midpoint. The second portion <NUM> may be, for example, threaded and may extend from a second end of the screw <NUM> to a position near the midpoint.

The connector <NUM> may include a first member <NUM>, a second member <NUM>, and a locking pin <NUM> coupling the first member <NUM> and a second member <NUM>. The terms "locking pin", "locking mechanism", "locking means", "fixation mechanism" and "fixation means" may be used interchangeably herein to refer to a structure that secures the first member <NUM> with respect to the second member <NUM> at a desired angulation. The first member <NUM> may include a first hinge connector <NUM> with an opening (not shown) to receive the locking pin <NUM>. The first member <NUM> may also include a channel <NUM> extending along the longitudinal axis of the first member <NUM> for receiving the first fastener <NUM>. The first member <NUM> may further include an opening (not shown) for receiving a first securement member <NUM> to secure the first fastener <NUM> to the first member <NUM> at a desired length. The opening may extend from an exterior surface of the first member <NUM> into the channel <NUM>. The second member <NUM> may include a second hinge connector <NUM> with an opening (not shown) to receive the locking pin <NUM>. The first hinge connector <NUM> and second hinge connector <NUM> are hingedly coupled together by the locking pin <NUM>. The second member <NUM> may also include a channel <NUM> extending along the longitudinal axis of the second member <NUM> for receiving the second fastener <NUM>. The second member <NUM> may further include an opening (not shown) for receiving a second securement member <NUM> to secure the second fastener <NUM> to the second member <NUM> at a desired length. The opening may extend from an exterior surface of the second member <NUM> into the channel <NUM>. The first hinge connector <NUM> is rotatably coupled to the second hinge connector <NUM> by the locking pin <NUM> and allows for the first member <NUM> and the second member <NUM> to rotate with respect to each other about the locking pin <NUM>. In addition, the locking pin <NUM> may secure the connector <NUM> at a desired angle between the first member <NUM> and the second member <NUM>. The angle between the first member <NUM> and the second member <NUM> may be, for example, approximately <NUM>° to <NUM>°. More preferably, the locking pin <NUM> may be secured at angles of, for example, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>° and <NUM>° between the first member <NUM> and the second member <NUM>.

Referring now to <FIG>, a rodless single level fusion system <NUM> is shown. The system <NUM> may include a first fastener or screw <NUM>, a second fastener or screw <NUM>, and a connector <NUM>. The connector <NUM> may be configured to receive the first fastener <NUM> and the second fastener <NUM>. The first fastener <NUM> may be, for example, a screw, straight rod, or curved rod, which may be smooth or fluted. The first fastener <NUM> may include a first portion <NUM> and a second portion <NUM>. The first portion <NUM> may have a, for example, hexagonal shape and may extend from a first end of the screw <NUM> to a position near the midpoint. The second portion <NUM> may be, for example, threaded and may extend from a second end of the screw <NUM> to a position near the midpoint. The second fastener <NUM> may be, for example, a screw, straight rod, or curved rod, which may be smooth or fluted. The second fastener <NUM> may include a first portion <NUM> and a second portion <NUM>. The first portion <NUM> may have a, for example, hexagonal shape and may extend from a first end of the screw <NUM> to a position near the midpoint. The second portion <NUM> may be, for example, threaded and may extend from a second end of the screw <NUM> to a position near the midpoint.

The connector <NUM> may include a first member <NUM>, a second member <NUM>, a hinge pin <NUM> coupling the first member <NUM> and a second member <NUM>, and a locking mechanism <NUM>. The first member <NUM> may include a first hinge connector <NUM> with an opening (not shown) to receive the hinge pin <NUM>. The first member <NUM> may also include an opening <NUM> extending along the longitudinal axis of the first member <NUM> for receiving the first fastener <NUM>. The first member <NUM> may further include an opening (not shown) for receiving a first securement member <NUM> to secure the first fastener <NUM> to the first member <NUM> at a desired length. The first member <NUM> may also include an adjustment member <NUM> with an opening <NUM>. The adjustment member <NUM> may be, for example, curved or arced. The opening <NUM> may be sized, for example, to receive a locking mechanism <NUM>. The connector <NUM> provides for angular adjustment, in multiple planes and includes a locking mechanism to provide rigid fixation between bone screws <NUM>, <NUM> to address variability in patient anatomy.

The second member <NUM> may include a second hinge connector <NUM> with an opening (not shown) to receive the pin <NUM>, as shown in <FIG>. The first hinge connector <NUM> and second hinge connector <NUM> are hingedly coupled together by the pin <NUM>. The second member <NUM> may also include an opening <NUM> extending along the longitudinal axis of the second member <NUM> for receiving the second fastener <NUM>. The second member <NUM> may further include an opening (not shown) for receiving a second securement member <NUM> to secure the second fastener <NUM> to the second member <NUM> at a desired length. The second member <NUM> may also include a groove <NUM> shaped to receive the adjustment member <NUM>. The second member <NUM> may also include a securement member (not shown) for the locking mechanism <NUM> to be secured to in order to lock the connector <NUM> at a desired angle between the first fastener <NUM> and the second fastener <NUM>. The first hinge connector <NUM> is rotatably coupled to the second hinge connector <NUM> by the locking pin <NUM> and allows for the first member <NUM> and the second member <NUM> to rotate with respect to each other about the hinge pin <NUM>.

Referring now to <FIG>, a single level fusion system <NUM> is shown. The system <NUM> is an alternative embodiment of the system <NUM> of <FIG>. The system <NUM> may include a first fastener or screw <NUM>, a second fastener or screw <NUM>, and a connector <NUM>. The connector <NUM> may be configured to receive the first fastener <NUM> and the second fastener <NUM>. The first and second fasteners <NUM>, <NUM> are of the type described above and will not be described again here for brevity sake. The connector <NUM> may include a first member <NUM>, a second member <NUM>, a hinge pin <NUM> coupling the first member <NUM> and a second member <NUM>, and a locking mechanism <NUM>. The first member <NUM> may be of the type described above with reference to <FIG> and will not be described again here for brevity sake. The connector <NUM> provides for angular adjustment, in multiple planes and includes a locking mechanism to provide rigid fixation between bone screws <NUM>, <NUM> to address variability in patient anatomy.

The second member <NUM> may include a second hinge connector <NUM> with an opening (not shown) to receive the pin <NUM>, as shown in <FIG>. The first hinge connector <NUM> and second hinge connector <NUM> are hingedly coupled together by the pin <NUM>. The second member <NUM> may also include an opening <NUM> extending along the longitudinal axis of the second member <NUM> for receiving the second fastener <NUM>. The second member <NUM> may further include an opening (not shown) for receiving a second securement member <NUM> to secure the second fastener <NUM> to the second member <NUM> at a desired length. The second member <NUM> may also include an opening <NUM> for receiving the locking mechanism <NUM>. The locking mechanism <NUM> may extend through the opening <NUM> in the adjustment member <NUM> in order to lock the connector <NUM> at a desired angle between the first fastener <NUM> and the second fastener <NUM>. The first hinge connector <NUM> is rotatably coupled to the second hinge connector <NUM> by the locking pin <NUM> and allows for the first member <NUM> and the second member <NUM> to rotate with respect to each other about the hinge pin <NUM>.

Another single level fusion system <NUM> is shown in <FIG>. The single level fusion system <NUM> may include a first fastener or screw <NUM>, a second fastener or screw <NUM>, and a connector <NUM>. The connector <NUM> may be configured to receive the first fastener <NUM> and the second fastener <NUM>. The first and second fasteners <NUM>, <NUM> are of the type described above and will not be described again here for brevity sake. The connector <NUM> may be, for example, a one piece connector. The connector <NUM> may include a first opening <NUM> extending from a top portion through to a bottom portion of the connector <NUM>. The first opening <NUM> may be sized and shaped to receive the first fastener <NUM>. The connector <NUM> may also include a second opening <NUM> extending from a top portion through to a bottom portion generally along a longitudinal axis of the connector <NUM>. The second opening <NUM> may be sized and shaped to receive the second fastener <NUM>. The first opening <NUM> may be spaced apart from the second opening <NUM>. The connector <NUM> may also include an opening (not shown) for receiving a first securement member <NUM> to secure the first fastener <NUM> in the first opening <NUM> at a desired length. The connector <NUM> may further include an opening (not shown) for receiving a second securement member <NUM> to secure the second fastener <NUM> in the second opening <NUM> at a desired length.

<FIG> shows yet another single level fusion system <NUM>. The single level fusion system <NUM> may include a first fastener or screw <NUM>, a second fastener or screw <NUM>, and a connector <NUM>. The connector or clamp connector <NUM> may be configured to receive the first fastener <NUM> and the second fastener <NUM>. The first and second fasteners <NUM>, <NUM> are of the type described above and will not be described again here for brevity sake. The connector <NUM> may be, for example, a two piece connector. The connector <NUM> may include a first member <NUM> and a second member <NUM>. The first and second members <NUM>, <NUM> may be coupled together with a first fastener <NUM> and a second fastener <NUM>. The connector <NUM> may also include a first opening <NUM> extending from a top portion through to a bottom portion of the connector <NUM>. The first opening <NUM> may be sized and shaped to receive the first fastener <NUM>. The connector <NUM> may also include a second opening <NUM> extending from a top portion through to a bottom portion generally along a longitudinal axis of the connector <NUM>. The second opening <NUM> may be sized and shaped to receive the second fastener <NUM>. The first opening <NUM> may be spaced apart from the second opening <NUM>. The connector <NUM> may also include an opening (not shown) for receiving a first securement member <NUM> to secure the first fastener <NUM> in the first opening <NUM> at a desired length. The connector <NUM> may further include an opening (not shown) for receiving a second securement member <NUM> to secure the second fastener <NUM> in the second opening <NUM> at a desired length.

The connectors <NUM> and <NUM>, as shown in <FIG>, may be, for example, non-pivoting locking blocks already positioned at the desired angle of correction.

A method (not claimed) of using the single level fusion system <NUM> is shown in <FIG>. The method may include preparing a patient's vertebrae for insertion of the single level fusion system <NUM>. Next, a first fastener <NUM> may be inserted into a first vertebra <NUM> and a second fastener <NUM> may be inserted into a second vertebra <NUM>, as shown in <FIG>. The first and second fasteners <NUM>, <NUM> are inserted to allow for divergence in only one dimension. As shown in <FIG>, the posterior-anterior view shows one trajectory for the first and second fasteners <NUM>, <NUM> in which divergence is only in one dimension, for example, cephalad-caudal. The cephalad directed fastener <NUM>, <NUM> may pass through one cortical layer and may end in the pedicle. The caudal directed fastener <NUM>, <NUM> may pass through the thick cortical layer of the superior facet of the inferior vertebra and end in the pedicle. Once the fasteners <NUM>, <NUM> are inserted into the vertebrae, the proximal ends of the fasteners <NUM>, <NUM> may be connected by the connector <NUM>. Referring now to <FIG>, the axial view shows the trajectory through the facet and pedicle for the trajectory drawn in <FIG>. After the connector <NUM> is coupled to the first and second fasteners <NUM>, <NUM>, the connector <NUM> may be secured at the desired angle between the first and second fasteners <NUM>, <NUM>. Finally, the patient's incision may be closed.

Another method (not claimed) of using the single level fusion system <NUM> is shown in <FIG>. The method may include preparing a patient's vertebrae for insertion of the single level fusion system <NUM>. Next, a first fastener <NUM> may be laterally inserted into a first vertebra <NUM> and a second fastener <NUM> may be laterally inserted into a second vertebra <NUM>, as shown in <FIG>. The first and second fasteners <NUM>, <NUM> are inserted to allow for divergence in two dimensions to increase pull-out strength. The fastener <NUM>, <NUM> inserted in the cephalad direction engages two cortices as well as the pedicle, while the fastener <NUM>, <NUM> inserted in the caudal direction engages four cortices. There are two trajectories for the first and second fasteners <NUM>, <NUM> in which divergence is in multiple directions, cephalad-caudal, medial-lateral and lateral right or lateral left. The cephalad directed fasteners <NUM>, <NUM> may pass through two cortices as well as the pedicle. The fasteners <NUM>, <NUM> inserted in a cephalad, medial-lateral, and lateral right or left direction achieves three dimensional stability. Alternatively, caudal directed fasteners <NUM>, <NUM> engage four cortical surfaces as well as the pedicle to also achieve three dimensional stability. Referring now to <FIG>, the axial view shows the medial lateral trajectory through the medial facet, pedicle, and lateral vertebral cortex of the vertebrae <NUM>, <NUM>. After the connector <NUM> is coupled to the first and second fasteners <NUM>, <NUM> the connector <NUM> may be secured at the desired angle between the first and second fasteners <NUM>, <NUM> and located lateral to the spinous process. Finally, the patient's incision may be closed.

Claim 1:
A single level spinal fusion system (<NUM>, <NUM>, <NUM>, <NUM>), comprising:
a first fastener assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the first fastener assembly (<NUM>), comprises:
a first fastener (<NUM>); and
a fastener (<NUM>), wherein an interior surface (<NUM>) of the fastener (<NUM>) is threaded to secure the fastener (<NUM>) to an exterior surface of a head (<NUM>) of the first fastener (<NUM>);
a second fastener assembly (<NUM>, <NUM>, <NUM>, <NUM>); and
an elongate member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) with a first end (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and a second end (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the elongate member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) couples the first fastener assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to the second fastener assembly (<NUM>, <NUM>, <NUM>, <NUM>), and wherein the first end (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) engages the first fastener assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and the second end (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is hingedly connected to the second fastener assembly (<NUM>, <NUM>, <NUM>, <NUM>).