Corpectomy device and methods of use thereof

A spinal fixation device includes a housing defining a chamber and a longitudinal axis, and an end plate assembly operatively coupled with the housing. The end plate assembly includes a first end plate configured to engage a vertebral body and first and second support assemblies operatively coupled to the first end plate. The first support assembly is selectively movable between a first position in which the first end plate is spaced apart from the housing and a second position in which the first end plate is adjacent the housing. The second support assembly is transitionable between a first state in which the first end plate has a first angular orientation and a second state in which the first end plate has a second angular orientation.

BACKGROUND

Technical Field

The present disclosure relates to an apparatus for treating spinal conditions, and more particularly, to an intervertebral implant.

Background of Related Art

The human spine includes thirty-three vertebrae. The vertebrae interlock with one another to form a spinal column. Each vertebra has a cylindrical bony body (vertebral body), two pedicles extending from the vertebral body, a lamina extending from the pedicles, two wing-like projections extending from the pedicles, a spinous process extending from the lamina, a pars interarticularis, two superior facets extending from the pedicles, and two inferior facets extending from the lamina. The vertebrae are separated and cushioned by thin pads of tough, resilient fiber known as inter-vertebral discs. Inter-vertebral discs provide flexibility to the spine and act as shock absorbers during activity. A small opening (foramen) located in each vertebra allows passage of the spinal cord. When the vertebrae are properly aligned, the spinal cord passes through without a problem. However, when the vertebrae are misaligned or a constriction is formed in the spinal canal, nerves of the spinal cord may get compressed and may cause back pain, leg pain, or other neurological disorders.

Disorders of the spine that may cause misalignment of the vertebrae or constriction of the spinal canal include spinal injuries, infections, tumor formation, herniation of the inter-vertebral discs (i.e., slippage or protrusion), arthritic disorders, and scoliosis. In these pathologic circumstances, surgery may be tried to either decompress the neural elements and/or fuse adjacent vertebral segments. Decompression may involve laminectomy, discectomy, or corpectomy. Laminectomy involves the removal of part of the lamina, i.e., the bony roof of the spinal canal. Discectomy involves removal of the inter-vertebral discs. Corpectomy involves removal of the vertebral body as well as the adjacent inter-vertebral discs.

A number of spinal surgical devices may be used to promote bony fusion after decompressing the spinal nerves. For instance, surgeons often replace the diseased vertebral tissue with one or more spinal cages and bone support matrix. Spinal cages support adjacent vertebral segments, while furthering spinal fusion of adjacent vertebral bodies. Scientists and clinicians have developed a number of devices and methods for decompressing spinal nerves. Improvements to these methods and devices are nevertheless still possible. Reference may be made to U.S. Patent Publication No. 2014/0277503 filed on Mar. 14, 2014, entitled “Spinal Fixation Device,” the entire content of which is incorporated herein by reference, for a detailed discussion of the construction and operation of a spinal fixation system and an instrumentation for use therewith.

Furthermore, intervertebral spacer implants used as a stand-alone device or provided in an assembly including a retention mechanism to help alleviate expulsion and movement of the implant when placed in the spine, are well known. Such implant assemblies are advantageous in providing an implant that is easier to insert in the spine. Intervertebral spacer implant assemblies which include a spacer and a plate, where the plate comprises a supplemental or alternative retention mechanism having one or more holes in the anterior end of the plate that are directed toward the superior, inferior or both end plates of adjacent vertebrae are also known in the art. Such implants are used to stabilize and immobilize the spinal segments in the treatment of single or multi-level degenerative disc disease, spinal stenosis, and failed previous fusions, as well as other spine conditions.

To meet the problem of preventing expulsion of the interbody device and for providing stability to the anatomy, a need exists for an spinal fixation device that can be secured to the spine and provide anterior column support and stabilization, while providing a maximum fusion area.

SUMMARY

In accordance with an embodiment of the present disclosure, there is provided a spinal fixation device including a housing defining a chamber and a longitudinal axis, and an end plate assembly operatively coupled with the housing. The end plate assembly includes a first end plate configured to engage a vertebral body and first and second support assemblies operatively coupled to the first end plate. The first support assembly is selectively movable between a first position in which the first end plate is spaced apart from the housing and a second position in which the first end plate is adjacent the housing. The second support assembly is transitionable between a first state in which the first end plate has a first angular orientation and a second state in which the first end plate has a second angular orientation. The first and second angular orientations are defined with respect to the longitudinal axis.

In an embodiment, the first support assembly may include a first support and a first rotatable member rotatably secured in the chamber of the housing. The first support may be rotatably coupled to the first rotatable member such that rotation of the first rotatable member causes axial displacement of the first support. The first support may include a protrusion portion pivotably coupled with the first end plate. The first support may define a slot along the longitudinal axis. The housing may include a pin configured to be received in the slot of the first support to facilitate axial movement of the first support.

In another embodiment, the housing may define a bore adjacent the first rotatable member.

In yet another embodiment, the housing may include an inner wall having a ledge to inhibit axial displacement of the first rotatable member.

In still yet another embodiment, the first rotatable member may include circumferentially arranged teeth.

In still yet another embodiment, the second support assembly may include a second support and a second rotatable member rotatably secured in a passage of the first support. The second support may be rotatably coupled to the second rotatable member such that rotation of the second rotatable member causes axial displacement of the second support. The second support may include a protrusion portion operatively coupled with the first end plate. The protrusion portion of the second support may define a bore configured to receive a pin. The first end plate may define a slot configured to receive the pin such that axial displacement of the second support enables selective transition of the first end plate from the first angular orientation to the second angular orientation.

In still yet another embodiment, the first support may define a locking bore adjacent the second rotatable member. The second rotatable member may include circumferentially arranged teeth.

In accordance with another embodiment of the present disclosure, there is provided a kit for spinal surgery. The kit includes a spinal fixation device and a surgical instrument. The spinal fixation device includes a housing defining a chamber and first and second end plate assemblies. The first end plate assembly is operatively coupled with the housing. The first end plate assembly includes a first end plate configured to engage a vertebral body and first and second support assemblies operatively coupled to the first end plate. The first support assembly is selectively movable between a first position in which the first end plate is spaced apart from the housing and a second position in which the first end plate is adjacent the housing. The second support assembly is movable between a first state in which the first end plate has a first angular orientation and a second state in which the first end plate has a second angular orientation. The second end plate assembly is interchangeable with the first end plate assembly. The second end plate assembly includes a second end plate having dimensions different from the first end plate, and third and fourth support assemblies. The third support assembly is selectively movable between a third position different from the first or second position of the first support assembly and a fourth position different from the first or second position of the first support assembly. The fourth support assembly is movable between a third state in which the second end plate has a third angular orientation different from the first or second angular orientation of the first end plate and a fourth state in which the second end plate defines a fourth angular orientation different from the first or second angular orientation of the first end plate. The surgical instrument includes an engaging portion configured to securely engage the housing of the spinal fixation device.

The surgical instrument may further includes a driver including an engaging portion having teeth configured to engage circumferentially arranged teeth of a first rotatable member of the first support assembly, such that rotation of the driver causes axial displacement of the first support of the first support assembly.

The first support may define a bore adjacent circumferentially arranged teeth of a second rotatable member. The bore of the first support may be dimensioned to receive the engaging portion of the driver of the surgical instrument to enable engagement of the teeth of the driver and the circumferentially arranged teeth of the second rotatable member, such that rotation of the driver causes axial displacement of the second support.

In accordance with another aspect of the present disclosure, there is provided a method of spinal surgery including positioning a spinal fixation device between adjacent vertebral bodies. The spinal fixation device includes a housing and an end plate assembly operatively coupled with the housing. The end plate assembly includes a first end plate configured to engage a vertebral body and first and second support assemblies operatively coupled to the first end plate. The method further includes adjusting a length of the spinal fixation device by transitioning the first support assembly from a first position in which the first end plate and the housing define a first distance to a second position in which the first end plate and the housing define a second distance different from the first distance; and varying an angular orientation of the first end plate with respect to a longitudinal axis defined by the spinal fixation device by transitioning the second support assembly from a first state in which the first end plate defines a first angular orientation to a second state in which the first end plate defines a second angular orientation.

In an embodiment, the method may further include securing the position of the first support assembly to maintain the length of the spinal fixation device. In addition, the method may further include securing the position of the second support assembly to maintain the angular orientation of the first end plate.

In another embodiment, inserting the spinal fixation device may include attaching a surgical insertion device to the housing.

In yet another embodiment, the method may further include distracting the adjacent vertebral bodies.

In yet another embodiment, adjusting the length of the spinal fixation device may include rotating a first rotatable member of the first support assembly to cause axial displacement of a first support coupled to the first end plate. Furthermore, varying the angular orientation of the first end plate may include rotating a second rotatable member of the second support assembly to cause axial displacement of a second support coupled to the first end plate.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Particular embodiments of the present disclosure will be described herein with reference to the accompanying drawings. As shown in the drawings and as described throughout the following description, and as is traditional when referring to relative positioning on an object, the terms “proximal” and “trailing” may be employed interchangeably, and should be understood as referring to the portion of a structure that is closer to a clinician during proper use. The terms “distal” and “leading” may also be employed interchangeably, and should be understood as referring to the portion of a structure that is farther from the clinician during proper use. In addition, the term “cephalad” or “cranial” is used in this application to indicate a direction toward a patient's head, whereas the term “caudad” indicates a direction toward the patient's feet. Further still, the term “medial” indicates a direction toward the middle of the body of the patient, whilst the term “lateral” indicates a direction toward a side of the body of the patient (i.e., away from the middle of the body of the patient). The term “posterior” indicates a direction toward the patient's back, and the term “anterior” indicates a direction toward the patient's front. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

With reference toFIGS. 1-4, an embodiment of the present disclosure is shown generally as a spinal fixation device500configured and adapted to be positioned between vertebral bodies to support vertebral bodies and to promote spinal fusion. By way of example, spinal fixation device500may be inserted into the patient laterally, posteriorly, anteriorly, or obliquely. Additionally, spinal fixation device500may be inserted into the patient through procedures such as, e.g., posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), lateral lumbar interbody fusion (LLIF), oblique lumbar interbody fusion (OLIF), or lateral extracavitary (LECA) procedures.

With reference toFIGS. 1-4 and 7, spinal fixation device500includes a housing510and an end plate assembly560interchangeably coupled with housing510. End plate assembly560includes a first end plate540and first and second support assemblies660,680operatively supporting first end plate540. Housing510includes a second end plate550. First and second end plates540,550are configured to engage end plates of adjacent vertebral bodies. In particular, first and second end plates540,550are configured to engage, e.g., endplates of superior and inferior vertebral bodies, respectively. With brief reference toFIGS. 5 and 6, each of first and second end plates540,550may include a plurality of pyramidal shaped spikes533a,533b(i.e., tetrahedrons) to aid in securing spinal fixation device500to the adjacent vertebral bodies for enhanced gripping of the vertebral bodies and minimizing movement of spinal fixation device500relative to the vertebral bodies. However, it is also contemplated that each of first and second end plates540,550may include ridges or similar projections to aid in securing spinal fixation device500to the vertebral bodies.

End plate assembly560may be configured as a modular assembly that is interchangeably mounted in housing510. For example, a plurality of end plate assemblies560may be provided with varying parameters such as, e.g., footprint and lordosis, such that the clinician may selectively attach a desired end plate assembly560to housing510to meet the needs of each patient or surgical procedure being performed. In this manner, end plate assembly560may be tailored to achieve a desired lordosis of first end plate540and a desired axial spacing between housing510and first end plate540, as will be discussed hereinbelow. It is also contemplated that the desired axial spacing between first and second end plates540,550may be tailored by selecting a desired length of housing510and/or end plate assembly560.

Spinal fixation device500may be made of titanium, titanium alloy, stainless steel, allograft bone, autologous bone graft, polyetheretherketone (PEEK), cobalt chrome, polymeric materials, a combination thereof, or any other suitable biocompatible material. In particular, spinal fixation device500may be formed of bone, or an artificial material other than bone which may be harder or stronger than bone, such as, e.g., ceramic materials. For example, various parts of spinal fixation device500such as, e.g., first and second end plates540,550, may be formed of titanium by 3D printing. Housing510may include a bone growth promoting material such as, e.g., bone morphogenic protein and hydroxyapatite. Housing510may define a cavity551to accommodate bone graft material therein. It is envisioned that bone support matrix can be placed within cavity551of housing510. As used herein, a “bone support matrix” is a material that facilitates osteogenesis. Suitable bone support matrices can be resorbable or nonresorbable and osteoconductive or osteoinductive. Non-limiting examples of suitable bone support matrices include synthetic materials, bone morphogenic proteins (BMPs), and heterologous, homologous, or autologous bone and derivatives thereof. The bone support matrix may be radiolucent on x-rays.

With reference toFIGS. 7 and 8, housing510includes first and second ends524,526and an outer wall512extending between first and second ends524,526. Outer wall512defines bores527a,527b,527cdimensioned to operatively engage insertion instrument6000(FIGS. 18 and 19), as will be discussed hereinbelow. For example, bores527a,527b,527cmay be defined in anterior or anterolateral portions of housing510. Outer wall512may further define a slot531(FIG. 8) and bores525dimensioned to receive pins527to operatively secure first support assembly660in housing510, as will be discussed hereinbelow. Outer wall512further defines a bore537dimensioned to receive a pin535that slides along a slot605defined in first support602in order to guide and facilitate axial movement of first support602within housing510. The length of slot605may define a range of axial displacement of first and second support assemblies660,680. Thus, the length of slot605may be tailored to meet the needs of each surgical procedure. For example, slot531and bores525,537may be defined in posterior or posterolateral portions of housing510.

With continued reference toFIGS. 7 and 8, first end524of housing510defines an aperture522and second end526of housing510includes second end plate550, e.g., integrally formed, with housing510. Housing510defines a chamber520configured to receive at least a portion of end plate assembly560through aperture522. End plate assembly560is selectively positionable within chamber520. End plate assembly560includes a first support assembly660releasably supported on a shoulder530(FIG. 11) of housing510and a second support assembly680operatively coupled with first support assembly660.

First support assembly660includes a first support602, a spacer606, and a first rotatable member610rotatably supported on shoulder530(FIG. 11) of housing510. First support602includes a threaded portion602athreadably coupled to first rotatable member610, and a protrusion portion604(FIG. 12) defining a bore604atherethrough. Bore604ais dimensioned to receive a pin555such that protrusion portion604is, e.g., pivotably, coupled to first end plate540. First support602defines a passage607dimensioned to receive at least a portion of second support assembly680. First support602further defines bores609dimensioned to receive pins617to operatively secure second support assembly680to first support602. First support602further defines a locking bore613providing access to second rotatable member690. Locking bore613is also dimensioned to receive a screw615to inhibit relative movement between second support assembly680and first support602.

First rotatable member610is positioned on shoulder530(FIG. 11) of housing510through slot531(FIG. 8) defined in, e.g., posterior or posterolateral portions, of housing510. Spacer606is placed in slot531to enclose and rotatably secure first rotatable member610within chamber520of housing510. Spacer606may act as a barrier to prevent any debris, tissue, or bone from entering any gaps that may be present between housing510and first rotatable member610. Further, spacer606may also inhibit debris from depositing in teeth612aof first rotatable member610.

Spacer606includes an arcuate surface606cconfigured to enable rotation of first rotatable member610. Spacer606defines opposing bores606aconfigured to be aligned with bores525(FIG. 8) defined in housing510to receive respective pins527therein to secure spacer606with housing510. Housing510further includes a ledge571(FIG. 11) such that when first rotatable member610is disposed on shoulder530of housing510, ledge571and shoulder530inhibit axial displacement of first rotatable member610within chamber520of housing510. Under such a configuration, rotation of first rotatable member610causes axial displacement of first support602threadably coupled with inner threads619(FIG. 7) of first rotatable member610. In this manner, the distance between first end plate540and housing510may be selectively adjusted.

For example, a length of spinal fixation device500can range from about 18 mm to about 32 mm. The length of spinal fixation device500may be based in part on the initial length of the device. For example, the length of the spinal fixation device500may be increased by an additional 4 mm. It is envisioned that the length of spinal fixation device500may be increased in any increment from about 0 mm to about 16 mm.

With continued reference toFIGS. 7 and 8, second support assembly680is operatively coupled to first end plate540to selectively adjust the angular orientation of first end plate540with respect to longitudinal axis “A-A” (FIG. 9). With brief reference toFIGS. 12-15, second support assembly680includes a second support682translatably disposed within passage607of first support602, a second spacer686, and a second rotatable member690rotatably supported within passage607of first support602. Second support682includes a threaded portion682athreadably coupled to second rotatable member690, and a protrusion portion684defining a bore684atherethrough. Bore684ais dimensioned to receive pin555(FIG. 8) such that protrusion portion684is coupled to first end plate540. Second support682further defines slots682bdimensioned to receive respective pins617extending through bores609of first support602to slidably secure second support682with first support602.

With continued reference toFIGS. 7 and 8, second spacer686defines bores689aligned with respective slots682bof second support682and bores609of first support602such that pins617are received through respective bores609of first support602, bores689of second spacer686, and slots682bof second support682. In this manner, second spacer686is secured with first support602while enabling axial displacement of second support682relative to first support602. Second spacer686may act as a barrier to prevent any debris, tissue, or bone from entering any gaps that may be present between the first support602and second rotatable member690. Furthermore, spacer686may also inhibit debris from depositing in teeth691of second rotatable member690.

With brief reference toFIGS. 7, 8, and 11, at least a portion of second rotatable member690of second support assembly680is rotatably disposed within passage607of first support602. In particular, second rotatable member690is disposed on a shoulder612of first support602. Under such a configuration, shoulder612of first support602and second spacer686inhibit axial displacement of second rotatable member690while enabling rotation of second rotatable member690. Second rotatable member690includes an inner wall693threadably coupled with threaded portion682aof second support682. In this manner, rotation of second rotatable member690causes axial displacement of second support682relative to first support602and housing510. Bore684aof protrusion portion684of second support682is aligned with slot542bof first end plate540such that pin555is received in slot542bof first end plate540and bore648aof protrusion portion684of second support682. Under such a configuration, axial displacement of second support682causes angular displacement of first end plate540. In particular, first end plate540may pivot about pin555disposed within bore542aof first end plate540. Slot542bhas a larger dimension than pin555to facilitate pivoting of first end plate540about pin555in bore542a.While second support assembly680is shown to selectively adjust the angular orientation of first end plate540with respect to longitudinal axis “A-A” (FIG. 9), it is also envisioned that second support assembly680may be operatively coupled to first end plate540to further adjust the distance between first end plate540and housing510.

Housing510defines an axis “X-X” (FIG. 9) orthogonal to a longitudinal axis “A-A” (FIG. 9) defined by outer housing510. For example, first end plate540may define a 0° angle with respect to axis “X-X” (i.e., a 90° angle with respect to axis “A-A”). Angular orientation of first end plate540may be selectively adjustable to better align first end plate540with an adjacent vertebral body to more accurately align spinal fixation device500with the adjacent vertebral body. First end plate540may be selectively adjustable in a range from about 0° to about 45° with respect to axis “X-X” (i.e., from about 90° to about 135° with respect to axis “A-A”).

With reference toFIGS. 16 and 17, there is shown an insertion instrument6000for use with spinal fixation device500to position spinal fixation device500between adjacent vertebral bodies. Insertion instrument6000includes a handle6010and an elongate body6020extending from handle6010. Insertion instrument6000defines a channel6035(FIG. 22) configured to receive an adjusting driver7500(FIG. 22). Elongate body6020includes engaging portion6032defining bores6037dimensioned to be aligned with bores527a,527c(FIG. 2) of housing510. Bores6037of engaging portion6032are dimensioned to receive respective securing members6039a,6039bto secure insertion instrument6000with housing510. Securing members6039a,6039bmay be threadably coupled with respective bores527a,527cof housing510to securely attach spinal fixation device500with insertion instrument6000(FIG. 19).

With reference toFIGS. 18-23, when engaging portion6032of insertion instrument6000is secured with housing510, respective securing members6039a,6039b(FIG. 17) are received within bores527a,527cof housing510, respectively. A driver7000may be utilized to threadably secure securing members6039a,6039bwithin respective bores527a,527b. Alignment of securing members6039a,6039bwith bores527a,527cprovides alignment between bore527bof housing510and channel6035of insertion instrument6000. Adjusting driver7500may be inserted into channel6035of insertion instrument6000to engage teeth612a(FIG. 2) of first rotatable member610with an engaging portion7520of the adjusting driver7500. Rotation of adjusting driver7500rotates first rotatable member610, causes axial displacement of first support602, which, in turn, causes axial displacement of first end plate540with respect to housing510. In this manner, end plate assembly560is selectively positionable relative to housing510through rotation of first rotatable member610. In this manner, a length of spinal fixation device500may be selectively tailored to, e.g., the intervertebral space.

With reference now toFIGS. 24 and 25, an engaging portion7520of adjusting driver7500may be inserted into locking bore613of first support602to operatively engage teeth691(FIG. 7) of second rotatable member690. In this manner, when adjusting driver7500is rotated, teeth691of second rotatable member690rotatably engage engaging portion7520of adjusting driver7500, which, in turn, causes axial displacement of second support682(FIG. 8) with respect to first support602. This interaction causes angular displacement of first end plate540or pivoting of first end plate540about bore604a(FIG. 7) of first support602. Such a configuration enables the clinician to selectively adjust angular orientation of first end plate540with respect to housing510to achieve the desired lordosis.

In this manner, first end plate540may be advantageously angled to provide a desired amount of lordosis tailored to the need of each patient. For example, first end plate540may be positioned substantially orthogonal to the longitudinal axis “A-A” (FIG. 9) and adjacent first end524of housing510. Alternatively, first end plate540may define an acute angle with respect to longitudinal axis “A-A” (FIG. 10) and spaced apart from first end524of housing510.

With reference now toFIGS. 26-28A, insertion instrument6000may be provided with an extension member8000configured to be attached to insertion instrument6000to provide a handle offset from a longitudinal axis “Y” defined by insertion instrument6000to facilitate insertion of spinal fixation device500into the patient. In particular, extension member8000includes an engaging portion8010configured to, e.g., frictionally, receive handle6010of insertion instrument6000, and a handle portion8020. Handle portion8020extends from engaging portion8010such that handle portion8020is offset from longitudinal axis “Y-Y” of insertion instrument6000.

With reference toFIGS. 29-31A, insertion instrument6000may be provided with an extension member9000in accordance with another embodiment of the present disclosure. Extension member9000includes an engaging portion9010configured to receive handle6010of insertion instrument6000. Extension member9000further includes a handle portion9020extending from engaging portion9010such that handle portion9020is offset from longitudinal axis “Y-Y” of insertion instrument6000. Handle portion9020includes a slider9030(FIG. 32) configured to engage notch6050defined in handle6010to further secure engaging portion9010with handle6010. Slider9030is operatively coupled to collar9040disposed about a neck portion9050of handle portion9020such that sliding of collar9040transitions slider9030between an engaged position in which slider9030securely engages notch6050of handle6010and a disengaged position in which the slider9030is disengaged from notch6050of handle6010. Collar9040may be coupled to a biasing member9042to bias slider9030towards the engaged state.

In use, the clinician first distracts vertebral bodies of interest to establish the intervertebral space. The clinician may then remove vertebral tissue, if necessary or desired. First and second supports602,682of first support assembly660and second support assembly680, respectively, are selectively positioned to achieve a desired orientation of first end plate540and length of spinal fixation device500. Insertion instrument6000is coupled with spinal fixation device500by, e.g., threadably, coupling engaging portion6032(FIG. 17) with bores527a,527c(FIG. 2) of housing510. Spinal fixation device500is then positioned adjacent a desired intervertebral space between vertebral bodies.

Upon inserting spinal fixation device500in the intervertebral space, adjusting driver7500can be inserted through channel6035(FIGS. 22 and 23) of insertion instrument6000to further adjust the axial distance between first end plate540and housing510by placing engaging portion7520through bore527bdefined in housing510such that teeth7504of engaging portion7520of adjusting driver7500engage teeth612aof first rotatable member610. In this manner, rotation of adjusting driver7500causes rotation of first rotatable member610, which, in turn, imparts axial translation of first support602. In this manner, the clinician may adjust the axial distance between first end plate540and housing510, i.e., length of spinal fixation device500. Adjusting driver7500is rotated until a desired length of spinal fixation device500is effected through axial movement of end plate assembly560. At this time, screws190may be inserted into respective bores521,527bto secure the axial position of first support602.

In addition, after removing adjusting driver7500and insertion instrument6000, adjusting driver7500can be inserted into locking bore613(FIG. 4) of first support602to operatively engage teeth691(FIG. 4) of second rotatable member690(FIG. 7) to adjust the angular orientation of first end plate540with respect to housing510(i.e., axis “A-A”) to mimic or closely match the degree of curvature along the spine comprising the adjacent vertebra. With reference toFIGS. 24 and 25, engaging portion7520of adjusting driver7500is inserted into locking bore613of first support602such that teeth7504of engaging portion7520of adjusting driver7500engage teeth691of second rotatable member690. Rotation of adjusting driver7500causes rotation of second rotatable member690, which, in turn, causes axial displacement of second support682. Axial displacement of second support682with respect to first support602enables the clinician to adjust the angular orientation of first end plate540with respect to housing510to achieve the desired lordosis or kyphosis. It is contemplated that the clinician may make further adjustments by alternating length adjustment and angular adjustment to achieve the desired length of spinal fixation device500and angular orientation of first end plate540. Upon achieving the desired length of spinal fixation device500and angular orientation of first end plate540, screw615may be placed in locking bore613. Screw615may be threadably secured in locking bore613by using driver7000. In particular, screw615may include a boss615a(FIG. 8) configured to be disposed between two adjacent teeth691of second rotatable member690to inhibit rotation of second rotatable member690.

Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, the above description, disclosure, and figures should not be construed as limiting, but merely as exemplifications of particular embodiments. For example, while the angular orientation of first end plate540is shown to be adjustable in cephalad and caudad directions, it is also contemplated that first end plate540may be adjustable in the medial and lateral directions. It is to be understood, therefore, that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure.