Patent Publication Number: US-10327914-B2

Title: Spinal implant system and method of use

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of application U.S. patent application Ser. No. 14/692,463, filed on Apr. 21, 2015, which is hereby incorporated by reference herein, in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to medical devices for the treatment of musculoskeletal disorders, and more particularly to a surgical system and method for treating a spine. 
     BACKGROUND 
     Spinal pathologies and disorders such as degenerative, isthmic and iatrogenic spondylolisthesis, degenerative disc disease, disc hemiation, and stenosis may result from disease and degenerative conditions caused by injury, prior surgery and aging. These spinal disorders typically result in symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility. Kyphosis and lysthesis or anterior translation of one vertebra in relation to the next may occur in many of these conditions and pathologies. 
     Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Current surgical treatment of these spinal disorders includes decompression and restoration of the normal alignment of the spine with concomitant fusion. Techniques used to commonly achieve these goals may include laminectomy, discectomy, internal spinal fixation, correction of the kyphotic deformity and the insertion of implantable interbody prosthetics. As part of these surgical treatments, spinal constructs, such as, for example, bone fasteners, spinal rods and interbody devices can be used to correct the pre-existing kyphosis and vertebral translational deformity and to provide stability to a treated region. For example, during surgical treatment, interbody implants and spinal pedicle screws can be used to correct abnormal alignment of the spinal vertebrae and provide stability serving to immobilize the spinal motion segment, and with bone graft, can result in a stable fusion. This disclosure describes an improvement over these prior technologies. 
     SUMMARY 
     In one embodiment, a method for treating a spine is provided. The method comprises the steps of: disposing an interbody implant adjacent a first vertebral surface and a second vertebral surface of an intervertebral disc space, the interbody implant engaging the vertebral surfaces at a selected angular orientation; connecting the interbody implant with at least one of the vertebral surfaces via at least one fastener that is engaged with the interbody implant and fixed with the vertebral surface such that the at least one fastener is movable to a plurality of axial orientations relative to the interbody implant; and manipulating the vertebral surfaces such that the at least one fastener is fixed relative to the interbody implant. In some embodiments, spinal implants, surgical instruments and systems are provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more readily apparent from the specific description accompanied by the following drawings, in which: 
         FIG. 1  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 2  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure; 
         FIG. 3  is a perspective view of components of one embodiment of a system in accordance with the principles of the present disclosure; 
         FIG. 4  is a cross section view of components shown in  FIG. 2 ; 
         FIG. 5  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 6  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 7  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 8  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 9  is a plan view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 10  is a plan view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 11  is a plan view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 12  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure; 
         FIG. 13  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure; 
         FIG. 14  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 15  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 16  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 17  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 18  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure; 
         FIG. 19  is a plan view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 20  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 21  is a para-sagittal cross section view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 22  is a para-sagittal cross section view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; 
         FIG. 23  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae; and 
         FIG. 24  is a side view of components of one embodiment of a system in accordance with the principles of the present disclosure disposed with vertebrae. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments of the surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of a surgical system including a spinal implant with variable angle screw fixation. In one embodiment, the systems and methods of the present disclosure are employed with a spinal joint fusion, for example, with a cervical region, a thoracic region, a lumbar region, and/or a sacral region of a spine. In some embodiments, the present surgical system comprises a spinal implant including a hyper-lordotic cage with variable angle screw fixation. In some embodiments, the present surgical system includes a spinal implant configured to facilitate curvature and compress a spine posteriorly without a complete pedicle-subtraction osteotomy (PSO). In some embodiments, the present surgical system is employed with a method including a Smith-Petersen osteotomy for removal of posterior-most bony structures. 
     In some embodiments, the present surgical system comprises a spinal implant including anti-back out screws. In some embodiments, the screws include multiple degrees of freedom and/or play, such as, for example, poly-axial and/or multi-axial screws when engaged with the spinal implant. In some embodiments, the screws are locked and prevented from back out by posterior compression of the spine. 
     In some embodiments, the present surgical system comprises a spinal implant including a hyper-lordotic wedged cage configured to restore a selected lordotic curve to the spine. In some embodiments, the cage includes apertures configured for engagement with anti-back out screws through the cage. In some embodiments, the screws are poly-axial at insertion until a posterior force is applied to impart and support the introduction of lordosis. In some embodiments, the screws are locked into place. In some embodiments, the screws are locked, such as, for example, with slots disposed in the cage. In some embodiments, the screws include heads that slide into the slots when lordosis is imparted and threads on the proximal end of the screws engage and/or penetrate threads or ridges around a proximal periphery of the screw holes. In some embodiments, the cage includes multi-part screw heads configured to prevent back out when a lordotic force is applied. In some embodiments, the cage is configured for disposal of bone graft or osteoinductive material. 
     In some embodiments, the present surgical system comprises a spinal implant including a cage configured for direct lateral interbody fusion (DLIF) procedures. In some embodiments, the present surgical system utilizes two screws. In some embodiments, the present surgical system utilizes three to four or more screws. In some embodiments, the present surgical system includes a cage configured for anterior lumbar interbody fusion (ALIF) procedures. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L5/S1 disc space in a range of 4 through 35 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L5/S1 disc space of 15 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L5 vertebral body in a range of 0 through 19 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L5 vertebral body of 9 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L4/L5 disc space in a range of −2 through 26 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L4/L5 disc space of 12 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a vertebral body in a range of 4 through −14 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a vertebral body of 3 degrees. In some embodiments, the present surgical system is employed with a method to achieve a selected average lordosis for a L4/L5 disc space of 40 degrees. 
     In some embodiments, the present surgical system includes a spinal implant configured to prevent plowing into an osteoporotic endplate causing a reduction in an increase of lordosis during posterior correction. In some embodiments, the present surgical system includes a spinal implant configured to prevent backing and/or kicking out of a disc space. 
     In some embodiments, the present surgical system includes a stabilizing lordotic cage. In some embodiments, the present surgical system is employed with a method to achieve and/or increase lordosis at a lumbo-sacral junction in a range of 25 through 40 degrees. In some embodiments, the cage is configured to prevent back out. In some embodiments, the present surgical system includes pedicle screws employed with a method including spondylolisthesis procedures to correct lordosis during the insertion of a posterior pedicle screw. 
     In some embodiments, the present surgical system includes a lordotic cage. In some embodiments, the present surgical system includes one or more self-retained, non-locked poly-axial screws. In some embodiments, the screws are locked to the cage and are configured to swivel. In some embodiments, the present surgical system is employed with a method such that the screws include a crown and are configured to prevent back out as the crown of the screw is locked in the cage while allowing angular movement. In some embodiments, the present surgical system is employed with a method such that during posterior surgery and compression, lordosis is increased and the screws do not back out of the cage. In some embodiments, the present surgical system is employed with a method such that during posterior compression, the screws will be disposed in a horizontal orientation and lordosis will increase to prevent back out. 
     In some embodiments, the present surgical system includes a spinal implant including screws that are locked and fixed. In some embodiments, the present surgical system includes a spinal implant including screws that allow for the correction of lordosis posteriorly. In some embodiments, the present surgical system is employed with a method to achieve and/or increase lordosis to 25 degrees. In some embodiments, the present surgical system is employed with a method to achieve and/or increase lordosis in a range of 25 through 30 degrees. In some embodiments, the present surgical system includes a spinal implant including a poly-axial non-locked screw that comprises two parts. In some embodiments, the spinal implant includes a part having a crown that threads into a metallic portion of a cage such that the crown is locked with the cage. In some embodiments, the spinal implant includes a part having a spherical poly-axial screw head that is retained in the crown and has 25 degrees of freedom of movement in one or a plurality of directions. In some embodiments, the screw is blocked and/or resisted and/or prevented from backing out of the spinal implant when tightened. In some embodiments, a screw driver has a double mechanism, which includes a part for engaging the screw and a part for engaging the crown. In some embodiments, the screw is configured for engagement with a stellar head and an octagonal part. 
     In some embodiments, the present surgical system includes a poly-axial non-locked or a mono-axial locked screw. In some embodiments, the present surgical system includes a spinal implant that allows use of a locked screw if lordosis is achieved and no further lordosis is desired. In some embodiments, the present surgical system allows the use of a first locked screw and a second poly-axial screw for a moderate increase of lordosis. In some embodiments, for maximum lordosis, both screws are poly-axial in a posterior approach. In some embodiments, a head of the screw is about 7 to about 8 millimeters (mm) in diameter. In some embodiments, a shaft of the screw is about 5 or 6 mm. In some embodiments, the screw is a self-tapping poly-axial screw. In some embodiments, the screw includes a locking thread surface configured to lock with the cage. 
     In some embodiments, the present surgical system includes a self-retaining non-locked poly-axial screw. In some embodiments, the screw includes a metallic thread configured to lock with the cage. In some embodiments, the screw is self-tapping and self-drilling to lock the poly-axial screw. In some embodiments, the present surgical system includes a screwdriver having two parts or tips, such as, for example, one hexagonal for the screw and one star-like for the crown. In some embodiments, the screwdriver comprises a threaded portion to lock into the crown. 
     In some embodiments, the present surgical system includes a poly-axial and/or a mono-axial screw utilized to increase lordosis during a posterior approach. In some embodiments, the present surgical system includes caps configured to block and/or lock the screws to prevent backing out. In some embodiments, if no posterior surgery is necessary, mono-axial locking and blocking screws are used. 
     In some embodiments, the present surgical system includes a cage having an anterior window. In some embodiments, the window allows additional packing of bone graft upon insertion of the cage with tissue. In some embodiments, the present surgical system includes implanting a cage at a L4/L5 vertebral level such that a bottom screw is offset to the left and a top screw is offset to the right. In some embodiments, each screw is slightly offset. In some embodiments, the screws are disposed in a convergent orientation. In some embodiments, a larger screw is inserted into a sacrum S1 and a shorter screw is inserted into a lumbar L5. 
     In some embodiments, the present surgical system includes a cage having anterior windows disposed adjacent to the screws to pack bone once the cage is inserted with tissue thereby preventing bone graft loss during cage insertion. In some embodiments, bone graft material can be packed into the cage by pushing the bone graft material into the cage through the anterior windows and into the disc space. In some embodiments, the present surgical system is employed with a method including a Smith Petersen osteotomy coupled with insertion of pedicle screws. In some embodiments, the screws are about 30 mm in length and have about a 4.5 to about a 5 mm diameter. In some embodiments, a lordosis of about 25 degrees is achieved. 
     In some embodiments, the present surgical system includes a cage that includes chambers for bone graft. In some embodiments, the cage includes a plurality of chambers for bone graft. In some embodiments, an outer surface of the cage is knurled and/or spiked. In some embodiments, the cage comprises a chamber for mobility of the screw, such as, for example, posterior mobility. In some embodiments, a poly-axial screw is inserted into the chamber. In some embodiments, the cage is about 26 mm in length and about 30 to about 38 mm wide. In some embodiments, the chambers are about 8 mm to about 9 mm wide. In some embodiments, the chamber for the screw is about 6 mm. In some embodiments, the outer surface of the cage is toothed to prevent kick out. In some embodiments, several poly-axial screws are provided with the cage. In some embodiments, four poly-axial screws are used with the cage for the L5/S1 vertebral level. In some embodiments, the cage includes screws that are laterally inserted with tissue. In some embodiments, four screws are used with the cage for a posterior approach. In some embodiments, four screws are used with an intervertebral body implant. In some embodiments, in the lumbar L4/5 vertebral levels and other vertebral levels including cervical, thoracic and lumbar vertebral levels, smaller poly-axial screws are provided. In some embodiments, the screw holes of the cage can be inserted laterally to avoid the dissection of a bifurcation to the right. In some embodiments, mono-axial or poly-axial screws can be inserted depending on the desire to increase lordosis. 
     In some embodiments, the present surgical system is employed with a method that includes a cervical spine application. In some embodiments, the present surgical system includes a cervical implant with a threaded step bolt screw mechanism in the middle of the implant. In some embodiments, the present surgical system includes a cervical implant with multiple poly-axial screws. In some embodiments, the cervical implant includes a threaded mechanism for a step bolt screw. 
     In some embodiments, the cervical spine application comprises poly-axial screws and a threaded step bolt screw mechanism, which increases lordosis with an anterior plate system. In some embodiments, the present surgical system includes a cervical cage having a threaded mechanism in the middle of the cervical cage for a step bolt screw to advance and to draw the spine to a cervical plate. In some embodiments, the cervical cage is about 7 mm in length and about 15 mm wide. In some embodiments, the screw is about 3.5 mm wide. In some embodiments, the threaded step bolt screw mechanism has about a 3 mm thread. In some embodiments, a 7 mm spacer is provided for use in the threaded step bolt screw mechanism. In some embodiments, the screw is about 30 mm in length. 
     In some embodiments, the present surgical system is employed with a method that includes correction of a cervical kyphotic deformity with a stand-alone instrument including a cage and a plate. In some embodiments, the surgical system includes step bolt screws, standard cervical bone screws and anterior plates. In some embodiments, the present surgical system is employed with a method that includes correction of a kyphotic cervical spine into a lordotic cervical spine such that an implant with a lordotic configuration, which includes freely movable but locked poly-axial screws, and step bolt screws are employed. 
     In some embodiments, the cervical cage has a width of about 17 mm and converges to adapt to the shape of an anterior disc space. In some embodiments, a top and a bottom of the cage is knurled to prevent kick out. In some embodiments, the cage has a lordosis including a 5 degree increment. In some embodiments, a step bolt mechanism is a poly-axial mechanism with 30 degrees of freedom of movement in each direction to allow tolerance in the plate placement and insertion of a step bolt screw from the plate into a threaded bore hole of the plate. In some embodiments, the cervical cage can be used as a stand-alone cage in the cervical spine. In some embodiments, mono-axial locked screws are employed. In some embodiments, poly-axial screws are provided that are non-locked to allow a small subsidence of the cage into the adjacent endplates to promote fusion and prevent kick out of the cage. In some embodiments, the cage is utilized with posterior spine instrumentation to provide additional lordosis. 
     In some embodiments, the present surgical system includes a narrow cervical plate to facilitate insertion of a poly-axial step bolt mechanism and allows extension for the poly-axial screws of the cage for locking after the reduction of the kyphosis has used the poly-axial properties of the screws. In some embodiments, the plate includes a narrow portion between the vertebrae and a larger portion at the level of the vertebrae to allow for the insertion of two screws per vertebrae. In some embodiments, a locking mechanism or anti kick out mechanism is provided that is configured for each screw to prevent the back out of the screw. 
     In some embodiments, present system and methods are employed with a lumbar technique. In some embodiments, a patient is positioned in a supine position on an operating room (OR) table with a radiolucent part of the table over the lumbar spine. In some embodiments, a cage is filled with bone graft material and/or bone enhancer. In some embodiments, once the cage has been inserted, the OR table is oriented to increase the lordosis of the lumbar spine. In some embodiments, if an end plate is in contact on c-arm fluoroscopy, a locking screw is inserted. In some embodiments, if the end plate is not in flush contact with tissue, a poly-axial screw is inserted to allow for further lordosis during posterior compression and osteotomy. In some embodiments, once the cage has been inserted, additional bone graft can be inserted through the anterior window to pack the inside of the cage so that bone fills into the disc space. In some embodiments, a posterior approach is utilized with posterior compression of the segment that increases the segmental lordosis. In some embodiments, Smith Petersen osteotomies of a vertebral segment may be employed to achieve lordosis. In some embodiments, frontal rotation of vertebrae is facilitated with non-locked poly-axial screws. In some embodiments, the cage is prevented from backing out with the poly-axial screws. 
     In some embodiments, the present surgical system includes a spinal implant comprising a 10 degree spacer including a 20 mm height in a front portion and 13 mm height in a back portion to achieve lordosis of 13 degrees. In some embodiments, the present surgical system includes a spinal implant comprising a 28 degree spacer including a 20 mm height in a front portion and 10 mm height in a back portion to achieve lordosis of 14 degrees and there is a gap posteriorly with no bony contact. In some embodiments, compression in the back portion is provided to increase lordosis to 24 degrees. 
     In some embodiments, the present surgical system includes blocked screws to prevent backing out while maintaining poly-axial freedom of movement. In some embodiments, the present system and methods provided can be utilized at a lumbar L3/L4 level with Smith Petersen osteotomies. In some embodiments, the present system and methods can achieve overall lordosis for three vertebral levels of about 30 degrees to 60 degrees. 
     In some embodiments, the present surgical system is employed with a method that includes resection of pedicles for further posterior compression to achieve a contact between the bony end plates and the superior and inferior portions of the cage. In some embodiments, the anterior windows in the cages allow for placement of packed additional bone graft material once the cage has been inserted to achieve fusion. In some embodiments, the present surgical system is employed with a method that includes a transformational lumbar interbody fusion (TLIF) approach that provides a posterior discectomy and further posterior compression. In some embodiments, the present system and methods provide about 30 degrees of correction. 
     The present disclosure may be understood more readily by reference to the following detailed description of the embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this application is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting. Also, in some embodiments, as used in the specification and including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It is also understood that all spatial references, such as, for example, horizontal, vertical, top, upper, lower, bottom, left and right, are for illustrative purposes only and can be varied within the scope of the disclosure. For example, the references “upper” and “lower” are relative and used only in the context to the other, and are not necessarily “superior” and “inferior”. 
     As used in the specification and including the appended claims, “treating” or “treatment” of a disease or condition refers to performing a procedure that may include administering one or more drugs to a patient (human, normal or otherwise or other mammal), employing implantable devices, and/or employing instruments that treat the disease, such as, for example, micro discectomy instruments used to remove portions bulging or herniated discs and/or bone spurs, in an effort to alleviate signs or symptoms of the disease or condition. Alleviation can occur prior to signs or symptoms of the disease or condition appearing, as well as after their appearance. Thus, treating or treatment includes preventing or prevention of disease or undesirable condition (e.g., preventing the disease from occurring in a patient, who may be predisposed to the disease but has not yet been diagnosed as having it). In addition, treating or treatment does not require complete alleviation of signs or symptoms, does not require a cure, and specifically includes procedures that have only a marginal effect on the patient. Treatment can include inhibiting the disease, e.g., arresting its development, or relieving the disease, e.g., causing regression of the disease. For example, treatment can include reducing acute or chronic inflammation; alleviating pain and mitigating and inducing re-growth of new ligament, bone and other tissues; as an adjunct in surgery; and/or any repair procedure. Also, as used in the specification and including the appended claims, the term “tissue” includes soft tissue, muscle, ligaments, tendons, cartilage and/or bone unless specifically referred to otherwise. 
     The following discussion includes a description of a surgical system and related methods of employing the surgical system in accordance with the principles of the present disclosure. Alternate embodiments are also disclosed. Reference is made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning to  FIGS. 1-10 , there are illustrated components of a surgical system, such as, for example, a spinal implant system  10 . 
     The components of spinal implant system  10  can be fabricated from biologically acceptable materials suitable for medical applications, including metals, synthetic polymers, ceramics and bone material and/or their composites. For example, the components of spinal implant system  10 , individually or collectively, can be fabricated from materials such as stainless steel alloys, commercially pure titanium, titanium alloys, Grade 5 titanium, super-elastic titanium alloys, cobalt-chrome alloys, stainless steel alloys, superelastic metallic alloys (e.g., Nitinol, super elasto-plastic metals, such as GUM METAL®), ceramics and composites thereof such as calcium phosphate (e.g., SKELITE™), thermoplastics such as polyaryletherketone (PAEK) including polyetheretherketone (PEEK), polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO 4  polymeric rubbers, polyethylene terephthalate (PET), fabric, silicone, polyurethane, silicone-polyurethane copolymers, polymeric rubbers, polyolefin rubbers, hydrogels, semi-rigid and rigid materials, elastomers, rubbers, thermoplastic elastomers, thermoset elastomers, elastomeric composites, rigid polymers including polyphenylene, polyamide, polyimide, polyetherimide, polyethylene, epoxy, bone material including autograft, allograft, xenograft or transgenic cortical and/or corticocancellous bone, and tissue growth or differentiation factors, partially resorbable materials, such as, for example, composites of metals and calcium-based ceramics, composites of PEEK and calcium based ceramics, composites of PEEK with resorbable polymers, totally resorbable materials, such as, for example, calcium based ceramics such as calcium phosphate such as hydroxyapatite (HA), corraline HA, biphasic calcium phosphate, tricalcium phosphate, or fluorapatite, tri-calcium phosphate (TCP), HA-TCP, calcium sulfate, or other resorbable polymers such as polyaetide, polyglycolide, polytyrosine carbonate, polycaroplaetohe and their combinations, biocompatible ceramics, mineralized collagen, bioactive glasses, porous metals, bone particles, bone fibers, morselized bone chips, bone morphogenetic proteins (BMP), such as BMP-2, BMP-4, BMP-7, rhBMP-2, or rhBMP-7, demineralized bone matrix (DBM), transforming growth factors (TGF, e.g., TGF-β), osteoblast cells, growth and differentiation factor (GDF), insulin-like growth factor  1 , platelet-derived growth factor, fibroblast growth factor, or any combination thereof. 
     Various components of spinal implant system  10  may have material composites, including the above materials, to achieve various desired characteristics such as strength, rigidity, elasticity, compliance, biomechanical performance, durability and radiolucency or imaging preference. The components of spinal implant system  10 , individually or collectively, may also be fabricated from a heterogeneous material such as a combination of two or more of the above-described materials. The components of spinal implant system  10  may be monolithically formed, integrally connected or include fastening elements and/or instruments, as described herein. In one embodiment, a spinal implant, as described herein, may be formed substantially of a biocompatible metal, such as titanium and selectively coated with a bone-growth promoting material, such as HA. In one embodiment, a spinal implant, as described herein, may be formed substantially of a biocompatible polymer, such as PEEK, and selectively coated with a biocompatible metal, such as titanium, or a bone-growth promoting material, such as HA. In some embodiments, titanium may be plasma sprayed onto surfaces of the spinal implant to modify a radiographic signature of the spinal implant and/or improve bony ongrowth to the spinal implant by application of a porous or semi-porous coating of titanium. 
     Spinal implant system  10  may be employed, for example, with minimally invasive procedures, including percutaneous techniques, mini-open surgical techniques and/or open surgical techniques to deliver and introduce instrumentation and/or spinal implants, such as, for example, an interbody implant, such as, for example, a interbody cage  12 , as shown in  FIG. 1 , at a surgical site within a body of a patient, which includes, for example, vertebrae V. In some embodiments, spinal implant system  10  can include spinal constructs including one or more bone fasteners, such as, for example, bone screws, spinal rods, tethers, connectors, plates and/or instruments, as described herein. In some embodiments, spinal implant system  10  is employed to achieve consistent, measured lordosis in a spinal segment of vertebrae V to be corrected and fused, and/or resist and/or prevent inducement of kyphosis. In some embodiments, spinal implant system  10  is employed to utilize the strength properties of a vertebral endplate of vertebrae V to resist and/or prevent subsidence and kyphosis. 
     Interbody cage  12  includes a body  13  that extends between an anterior surface  14  and a posterior surface  16 . Anterior surface  14  is configured to face an anterior side of a body and be disposed adjacent an anterior portion of vertebrae, such as, for example, an anterior portion A 1  of a lumbar spine, which includes an L5-S1 intervertebral space of vertebrae V. Posterior surface  16  is configured to face a posterior side of a patient body and be disposed adjacent a posterior portion of vertebrae, such as, for example, a posterior portion P 1  of the L5-S1 intervertebral space. 
     Interbody cage  12  includes a vertebral engaging surface  18  and a vertebral engaging surface  20 . Surface  18  is substantially planar and configured to engage endplate tissue of a vertebral body, such as, for example, an endplate E 1  of an L5 vertebral body, as shown in  FIGS. 1 and 5-8 . Surface  20  is configured to engage endplate tissue of a vertebral body, such as, for example, an endplate E 2  of an S1 vertebral body. In some embodiments, surfaces  18 ,  20  may include teeth. In some embodiments, surfaces  18 ,  20  may be rough, textured, porous, semi-porous, dimpled, knurled, toothed, grooved and/or polished such that it facilitates engagement with tissue. In some embodiments, the vertebral tissue may include intervertebral tissue, endplate surfaces and/or cortical bone. 
     Surface  18  is disposed at a selected angular orientation α relative to surface  20  to form a wedge shaped configuration of interbody cage  12 . In some embodiments, this configuration of interbody cage  12  achieves segmental lordosis of one or more vertebra, as described herein. In some embodiments, angle α includes a range of −2 through 26 degrees. In some embodiments, angle α includes 12 degrees. In some embodiments, angle α includes a range of 4 through −14 degrees. In some embodiments, angle α includes 3 degrees. In some embodiments, angle α includes 40 degrees. 
     Interbody cage  12  includes a surface  22  disposed anteriorly along interbody cage  12 . Surface  22  defines a portion of an opening, such as, for example, an axial slot  30 , as shown in  FIGS. 1 and 6 . Slot  30  extends between surface  22  and surface  18 , and includes a portion of surface  18 . Slot  30  extends transverse to a longitudinal axis of body  13  and is disposed in alignment with vertebra L5 for fixation with tissue. 
     Slot  30  is configured for disposal of a bone fastener, such as, for example, a bone screw  32 , as described herein. Spinal implant system  10  includes one or more bone screws  32 , as shown in  FIG. 2 , for attaching interbody cage  12  with tissue, as described herein. Bone screw  32  comprises a portion, such as, for example, a spherical head  50  and a portion, such as, for example, an elongated threaded shaft  52  configured for penetrating tissue. Bone screws  32  are engageable with interbody cage  12  between a first configuration such that bone screws  32  are movable to one or a plurality of axial orientations in angular ranges β 1 , β 2  relative to axes A 2 , A 3 , described herein, relative to interbody cage  12  and a second configuration such that bone screws  32  are fixed relative to interbody cage  12 . 
     Head  50  includes an engagement portion  54  configured for engagement with a surgical instrument  56 , as shown in  FIG. 3 . Shaft  52  has a cylindrical cross section configuration and includes an outer surface having an external thread form. In some embodiments, the external thread form may include a single thread turn or a plurality of discrete threads. In some embodiments, other engaging structures may be located on the shaft, such as, for example, nail configuration, barbs, expanding elements, raised elements and/or spikes to facilitate engagement of the shaft with tissue, such as, for example, vertebrae. 
     In some embodiments, all or only a portion of shaft  52  may have alternate cross section configurations, such as, for example, oval, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, undulating, arcuate, variable and/or tapered. In some embodiments, the outer surface of shaft  52  may include one or a plurality of openings. In some embodiments, all or only a portion of the outer surface of shaft  52  may have alternate surface configurations, such as, for example, smooth and/or surface configurations to enhance fixation with tissue, such as, for example, rough, arcuate, undulating, porous, semi-porous, dimpled, polished and/or textured. In some embodiments, all or only a portion of shaft  52  may be cannulated. 
     Slot  30  extends in a transverse configuration relative to surface  18  and defines an axis A 2 . In some embodiments, slot  30  facilitates movement of bone screw  32  to one or a plurality of axial orientations in an angular range of β 1  relative to axis A 2 . In some embodiments, bone screw  32  is disposed with slot  30  and engageable with body  13  such that bone screw  32  comprises a multi-axial and/or poly-axial fastener extending from body  13 . 
     In some embodiments, a portion of slot  30  includes a threaded portion  34 . Portion  34  is configured for engagement with a member, such as, for example, a crown  36 . Crown  36  is configured to support bone screw  32 . In some embodiments, bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  30 . In some embodiments, bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in an angular range of β 1  relative to axis A 2  and crown  36 . In some embodiments, bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue and/or body  13 . 
     Surface  22  defines a portion of an opening, such as, for example, an axial slot  40 , as shown in  FIG. 5 . Slot  40  extends between surface  22  and surface  20 , and includes a portion of surface  20 . Slot  40  is disposed in alignment with vertebra S1 for fixation with tissue. 
     Slot  40  is configured for disposal of a bone screw  32 , as described herein. Slot  40  extends in a transverse configuration relative to surface  20  and defines an axis A 3 . In some embodiments, slot  40  facilitates movement of bone screw  32  to one or a plurality of axial orientations in an angular range of β2 relative to axis A 3 . In some embodiments, bone screw  32  is disposed with slot  40  and engageable with body  13  such that bone screw  32  comprises a multi-axial and/or poly-axial fastener extending from body  13 . In some embodiments, bone screw  32  disposed with slot  40  may be alternately configured relative to a bone screw  32  disposed with slot  30  and/or comprise alternate movement or rotation capabilities relative to a bone screw  32  disposed with slot  30 . 
     In some embodiments, a portion of slot  40  includes a threaded portion  44 . Portion  44  is configured for engagement with a crown  36 , as described herein. Crown  36  is configured to support a bone screw  32  disposed with slot  40 . In some embodiments, bone screw  32  slidably engages and/or translates relative to crown  36  disposed with slot  40  and/or the surface that defines slot  40 . In some embodiments, bone screw  32  moves and/or rotates to one or a plurality of axial orientations in an angular range of β 2  relative to axis A 3  and crown  36  disposed with slot  40 . In some embodiments, bone screw  32  abuts and/or frictionally engages crown  36  disposed with slot  40  to resist and/or prevent backout of bone screw  32  disposed with slot  40  from tissue and/or body  13 . 
     Crowns  36  are configured for disposal within slots  30 ,  40 , respectively, and engageable with portions  34 ,  44 . Crown  36  includes a wall  60  having a surface  62  and a surface  64 , as shown in  FIG. 4 . Surface  62  is threaded to facilitate engagement with slots  30 ,  40 . Surface  64  defines a protrusion, such as, for example, a circumferential flange  66 . Flange  66  is configured to retain head  50  and facilitate rotation of bone screw  32  forming a self-retained, non-locked multi-axial or poly-axial screw. In some embodiments, bone screw  32  is configured in a locked orientation with crown  36  such that screw  32  is prevented from backing out while maintaining movement within the plurality of axial orientations β 1 , β 2  relative to interbody cage  12 . In some embodiments, bone screw  32  is configured in a locked orientation with crown  36  such that screw  32  is prevented from backing out while allowing angular movement and maintaining movement within the plurality of axial orientations β 1 , β 2  relative to interbody cage  12 . 
     In some embodiments, surface  64  is smooth to facilitate rotation of head  50  within crown  36  within the plurality of axial orientations β 1 , β 2  relative to interbody cage  12  in the first configuration, as shown by arrows C in  FIG. 4 . As bone screw  32  rotates, head  50  engages surface  64  for a friction fit between surface  64  and head  50  into the second configuration to fix bone screw  32  relative to interbody cage  12 . In some embodiments, all or only a portion of surface  64  may have alternate surface configurations, such as, for example, rough, arcuate, undulating, porous, semi-porous, dimpled, polished and/or textured to enhance fixation with head  50 . 
     In some embodiments, slot  40  is offset in a lateral direction and slot  30  is offset in a contralateral direction. In some embodiments, slots  30 ,  40  are slightly offset. In some embodiments, slots  30 ,  40  are disposed in a convergent orientation. 
     In some embodiments, as shown for example in  FIG. 10 , spinal implant system  10  includes an interbody cage  12   a , similar to interbody cage  12 , which includes a surface that defines an opening configured to receive an agent, which may include bone graft (not shown) and/or other materials, as described herein, for employment in a fixation or fusion treatment. In some embodiments, the cross-sectional geometry of interbody cage  12   a  may have various configurations, such as, for example, round, oval, oblong, triangular, polygonal having planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe shape, U-shape or kidney bean shape. In some embodiments, interbody cage  12   a  includes one or more anterior windows  29   a . In some embodiments, window  29   a  allows for additional packing of bone graft upon insertion of interbody cage  12   a  with tissue. 
     In some embodiments, bone screw  32  may be engaged with tissue in various orientations, such as, for example, series, parallel, offset, staggered and/or alternate vertebral levels. In some embodiments, one or more of bone screws  32  may comprise multi-axial screws, sagittal angulation screws, pedicle screws, mono-axial screws, uni-planar screws, facet screws, fixed screws, tissue penetrating screws, conventional screws, expanding screws, wedges, anchors, buttons, clips, snaps, friction fittings, compressive fittings, expanding rivets, staples, nails, adhesives, posts, fixation plates and/or posts. 
     In assembly, operation and use, as shown in  FIGS. 5-9 , spinal implant system  10 , similar to the systems described herein, is employed with a surgical procedure for treatment of a spinal disorder, such as those described herein, affecting a section of a spine of a patient. Spinal implant system  10  may also be employed with other surgical procedures. To treat the affected section of vertebrae V of a subject body of a patient, the patient is oriented such that the procedure can be performed anteriorly to provide direct anterior access to an L5-S1 intervertebral space along a surgical pathway, described herein, while avoiding selected muscular and abdominal anatomical structures. While some examples shown herein depict L5 and S1, it should be understood that the various embodiments could be used in procedures for the treatment of any selected levels of the human spine, including the cervical spine, thoracic spine and/or lumbar spine, including but not limited to disposing interbody cage  12   a , similar to interbody cage  12  with screws  32 , with the L4-L5 disc space, as shown in  FIG. 10 . In some embodiments, spinal implant system  10  is employed with a patient in a prone position, and/or employed with various additional surgical approaches to the spine, including posterior, posterior mid-line, direct lateral, postero-lateral, and/or antero lateral approaches. 
     In some embodiments, a discectomy is performed adjacent the L5-S1 intervertebral space. In some embodiments, sequential trial implants are delivered and used to distract the L5-S1 intervertebral space and apply appropriate tension in the L5-S1 intervertebral space allowing for indirect decompression. In some embodiments, the size of interbody cage  12  is selected after trialing, interbody cage  12  is visualized by fluoroscopy and oriented before malleting into the L5-S1 intervertebral space. 
     A preparation instrument is employed to remove disc tissue, fluids, adjacent tissues and/or bone, and scrape and/or remove tissue from endplate surfaces E 1  of vertebra L5 and/or endplate surface E 2  of vertebra S1. In some embodiments, vertebral facets, such as, for example, an L5 inferior facet and an S1 superior facet are resected. A trans-foraminal discectomy is performed to create vertebral space between vertebral bodies L5, S1. 
     In some embodiments, a resection of pedicles is conducted for further posterior compression to achieve a contact between the bony end plates and the superior and inferior portions of interbody cage  12 . In some embodiments, the present surgical system is employed with a method that includes a transformational lumbar interbody fusion (TLIF) approach to provide a posterior discectomy and further posterior compression. 
     Interbody cage  12  is selected such that surface  18  is disposed at a selected angular orientation α relative to surface  20 , as described herein. In some embodiments, pilot holes or the like are made in selected vertebra L5 and vertebra S1 of vertebrae V adjacent the L5-S1 intervertebral space for receiving bone screws  32 . An inserter (not shown) is attached with interbody cage  12  to deliver interbody cage  12  adjacent to a surgical site for implantation adjacent the L5-S1 intervertebral space. Anterior surface  14  faces an anterior side of the body adjacent anterior portion A 1  and posterior surface  16  faces a posterior side P 1  of the body, as described herein. Surface  18  engages endplate tissue of endplate E 1  and surface  20  is disposed facing endplate tissue of endplate E 2 . 
     Slot  30  is aligned with vertebra L5 and oriented to receive a bone screw  32 /crown  36  assembly. In some embodiments, screw  32  and crown  36  are separately disposed with slot  30  and engaged therein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  30  in a first configuration, as described herein. 
     Bone screw  32  is engaged with tissue of vertebra L5. Bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in an angular range of β 1  relative to axis A 2  and crown  36 . Bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue of vertebra L5 and/or body  13 . 
     Slot  40  is aligned with vertebra S1 and oriented to receive a bone screw  32 /crown  36  assembly. In some embodiments, screw  32  and crown  36  are separately disposed with slot  40  and engaged therein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  40  in a first configuration, as described herein. 
     Bone screw  32  is engaged with tissue of vertebra S1. Bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in an angular range of β 2  relative to axis A 3  and crown  36 . Bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue of vertebra S1 and/or body  13 . 
     Interbody cage  12  is disposed with vertebrae L5, S1 such that interbody cage  12  comprises a fulcrum between endplate surfaces E 1 , E 2 . Endplate surfaces E 1 , E 2  engage surfaces  18 ,  20  to achieve a selected segmental lordosis of vertebrae L5, S1 as facilitated by angle α. Endplate surfaces E 1 , E 2  engage surfaces  18 ,  20  such that bone screw  32  abuts and/or frictionally engages crown  36  to lock screws  32  and interbody cage  12  in a fixed configuration with vertebrae L5, S1. 
     In some embodiments, spinal implant system  10  includes a surgical instrument I, as shown in  FIGS. 6-9 , employed to manipulate vertebrae L5, S1. Surgical instrument I includes lever arms, such as, for example, extender pedicles screws  70 . Pedicle screws  70  are attached with vertebrae L5, S1 to manipulate vertebrae L5, S1. Surgical instrument I manipulates vertebrae L5, S1 such that endplate surfaces E 1 , E 2  exert a compressive force, in the direction shown by arrows D in  FIG. 7 , on interbody cage  12  such that interbody cage  12  comprises a fulcrum during compression and screws  32  are movable to one or a plurality of axial orientations in a first configuration, as described herein. As such, surgical instrument I manipulates vertebrae L5, S1 to rotate vertebrae L5, S1, to achieve segmental lordosis of vertebrae L5, S1 as determined by angle α and locks screws  32  and interbody cage  12  in a fixed configuration with vertebrae L5, S1. In some embodiments, spinal implant system  10  includes interbody cage  12  employed in connection with a surgical procedure and method to treat a spine and facilitate manipulating vertebrae to a selected curvature and compression of a spine posteriorly without a complete PSO. For example, interbody cage  12  is employed with the surgical procedure and method, which includes a Smith-Petersen osteotomy for removal of only posterior-most bony structures of selected vertebral levels of vertebrae V, as described herein. 
     In some embodiments, spinal implant system  10  may comprise various surgical instruments, such as, for example, drivers, extenders, reducers, spreaders, distractors, blades, clamps, forceps, elevators and drills, which may be alternately sized and dimensioned, and arranged as a kit. In some embodiments, spinal implant system  10  may comprise the use of microsurgical and image guided technologies, such as, for example, surgical navigation components employing emitters and sensors, which may be employed to track introduction and/or delivery of the components of system  10  including the surgical instruments to a surgical site. See, for example, the surgical navigation components and their use as described in U.S. Pat. Nos. 6,021,343, 6,725,080 and 6,7969,88, the entire contents of each of these references being incorporated by reference herein. 
     Upon completion of a procedure, as described herein, the surgical instruments, assemblies and non-implanted components of spinal implant system  10  are removed and the incision(s) are closed. One or more of the components of spinal implant system  10  can be made of radiolucent materials such as polymers. Radiopaque markers may be included for identification under x-ray, fluoroscopy, CT or other imaging techniques. In some embodiments, the use of surgical navigation, microsurgical and image guided technologies, as described herein, may be employed to access, view and repair spinal deterioration or damage, with the aid of spinal implant system  10 . In some embodiments, spinal implant system  10  may include one or a plurality of interbody implants, rods, tethers, plates, connectors and/or bone fasteners for use with a single vertebral level or a plurality of vertebral levels. In some embodiments, spinal implant system  10  may include one or a plurality of bone fasteners that may comprise multi-axial screws, sagittal angulation screws, pedicle screws, mono-axial screws, uni-planar screws, facet screws, fixed screws, tissue penetrating screws, conventional screws, expanding screws, wedges, anchors, buttons, clips, snaps, friction fittings, compressive fittings, expanding rivets, staples, nails, adhesives, posts, fixation plates and/or posts. 
     In one embodiment, spinal implant system  10  includes an agent, which may be disposed, packed, coated or layered within, on, adjacent or about the components and/or surfaces of spinal implant system  10 , and/or disposed with tissue. In some embodiments, the agent may include bone growth promoting material, such as, for example, bone graft to enhance fixation of the components and/or surfaces of spinal implant system  10  with vertebrae. In some embodiments, the agent may include one or a plurality of therapeutic agents and/or pharmacological agents for release, including sustained release, to treat, for example, pain, inflammation and degeneration. 
     In one embodiment, as shown in  FIG. 11 , spinal implant system  10 , similar to the systems and methods described herein, comprises an interbody cage  112 , similar to interbody cage  12  described herein. Interbody cage  112  includes a plurality of bone screws  32 , as described herein, fastened with a first vertebral level, such as, for example, an L5 vertebral level and a plurality of bone screws  32  fastened with a second vertebral level, such as, for example, an S1 vertebral level. 
     Interbody cage  112  includes a plurality of spaced apart slots  130   a ,  130   b , similar to slot  30  described herein, which are aligned with vertebra L5 and oriented to receive bone screw  32 /crown  36  assemblies, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surfaces that define slots  130   a ,  130   b  in a first configuration, as described herein. Bone screws  32  disposed with slots  130   a ,  130   b  are engaged with tissue of vertebra L5 and rotatable to a plurality of axial orientations in a selected angular range relative to its axis and crown  36 . Bone screws  32  abut and/or frictionally engage crowns  36  of slots  130   a ,  130   b  to resist and/or prevent backout of bone screws  32  from tissue of vertebra L5 and/or interbody cage  112 . 
     Interbody cage  112  includes a plurality of spaced apart slots  140   a ,  140   b , similar to slot  40  described herein, which are aligned with vertebra S1 and oriented to receive bone screw  32 /crown  36  assemblies, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surfaces that define slots  140   a ,  140   b  in a first configuration, as described herein. Bone screws  32  disposed with slots  140   a ,  140   b  are engaged with tissue of vertebra S1 and rotatable to a plurality of axial orientations in a selected angular range relative to its axis and crown  36 . Bone screws  32  abut and/or frictionally engage crowns  36  of slots  140   a ,  140   b  to resist and/or prevent backout of bone screws  32  from tissue of vertebra S1 and/or interbody cage  112 . 
     Interbody cage  112  is disposed with vertebrae L5, S1 such that interbody cage  112  achieves a selected segmental lordosis of vertebrae L5, S1 similar to that described herein. The endplate surfaces of vertebrae L5, S1 engage the surfaces of interbody cage  112  such that bone screws  32  abut and/or frictionally engage crowns  36  of slots  130   a ,  130   b ,  140   a ,  140   b  to lock screws  32  and interbody cage  112  in a fixed configuration with vertebrae L5, S1. 
     In one embodiment, as shown in  FIG. 12 , spinal implant system  10 , similar to the systems and methods described herein, comprises an interbody cage  212 , similar to interbody cage  12  described herein. Interbody cage  212  includes a plurality of cavities, such as, for example, chambers  229  configured for disposal of an agent, as described herein. The outer surface of interbody cage  212  includes teeth  221 , which may be oriented in one or a plurality of directions for engagement and fixation with tissue. In some embodiments, the outer surface of interbody cage  212  may be rough, textured, porous, semi-porous, dimpled, knurled, grooved and/or polished to facilitate engagement with tissue. 
     Interbody cage  212  defines an opening, such as, for example, a spheroidal joint  230 . Spheroidal joint  230  is aligned with a selected vertebral level and oriented to receive a head  50  of a bone screw  32 , as described herein. Spheroidal joint  230  supports head  50  and head  50  slidably engages the surfaces that define spheroidal joint  230  for relative movement therein in a first configuration, as described herein. 
     Bone screw  32  disposed with spheroidal joint  230  is engaged with tissue of a selected vertebral level and rotatable to a plurality of axial orientations in a selected angular range relative to its axis and spheroidal joint  230 . Bone screw  32  abuts and/or frictionally engages the surfaces that define spheroidal joint  230  to resist and/or prevent backout of bone screw  32  from tissue of a selected vertebral level and/or interbody cage  212 . Interbody cage  212  is disposed with selected vertebral levels such that interbody cage  212  achieves a selected segmental lordosis of the selected vertebral levels, similar to that described herein. 
     The endplate surfaces of the selected vertebral levels engage the surfaces of interbody cage  212  such that bone screw  32  abuts and/or frictionally engages the surfaces that define spheroidal joint  230  to lock screw  32  and interbody cage  212  in a fixed configuration with the selected vertebral levels. In some embodiments, interbody cage  212  can include one or a plurality of spheroidal joints  230 , which may be aligned, co-axial, define a trajectory, arcuately oriented, offset, staggered, in series, parallel, transverse and/or spaced apart. In some embodiments, as shown in  FIG. 13 , interbody cage  212  includes a spheroidal joint  230   a  having an extended chamber  231  with an increase in posterior translation and/or mobility of head  50  to facilitate posterior translation and/or mobility of screw  32 . 
     In one embodiment, as shown in  FIGS. 14-16 , spinal implant system  10 , similar to the systems and methods described herein, comprises an interbody cage  312 , similar to interbody cage  12  described herein. Interbody cage  312  is configured for implantation along a direct lateral interbody fusion (DLIF) approach. 
     Interbody cage  312  is selected and the components of interbody cage  312  are delivered via a lateral surgical pathway to the surgical site such that a surface  318  is disposed at a selected angular orientation α 2  relative to a surface  320 , similar to that described herein. Pilot holes or the like are made in selected vertebra L4 and vertebra L5 of vertebrae adjacent the L4-L5 intervertebral space for receiving bone screws  32 . An inserter (not shown) is attached with interbody cage  312  to deliver interbody cage  312  adjacent to a surgical site for implantation adjacent the L4-L5 intervertebral space. Anterior surface  314  faces an anterior side of the body adjacent anterior portion A 1  and posterior surface  316  faces a posterior side P 1  of the body, as described herein. Surface  318  engages endplate tissue of endplate E 1  and surface  320  is disposed facing endplate tissue of endplate E 2 . 
     A slot  330 , similar to slot  30  described herein, is aligned with vertebra L4 and oriented to receive a bone screw  32 /crown  36  assembly, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  330  in a first configuration, as described herein. 
     Bone screw  32  is engaged with tissue of vertebra L4. Bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in a selected angular range relative to its axis and crown  36 , similar to that described herein. Bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue of vertebra L4 and/or interbody cage  312 . 
     A slot  340 , similar to slot  40  described herein, is aligned with vertebra L5 and oriented to receive a bone screw  32 /crown  36  assembly, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  340  in a first configuration, as described herein. 
     Bone screw  32  is engaged with tissue of vertebra L5. Bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in a selected angular range relative to its axis and crown  36 . Bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue of vertebra L5 and/or interbody cage  312 . 
     Interbody cage  312  is disposed with vertebrae L4, L5 such that interbody cage  312  comprises a fulcrum between endplate surfaces E 1 , E 2 . Endplate surfaces E 1 , E 2  engage surfaces  318 ,  320  to achieve a selected segmental lordosis of vertebrae L4, L5 as facilitated by angle α 2 . Endplate surfaces E 1 , E 2  engage surfaces  318 ,  320  such that bone screw  32  abuts and/or frictionally engages crown  36  to lock screws  32  and interbody cage  312  in a fixed configuration with vertebrae L4, L5. 
     In some embodiments, spinal implant system  10  includes a surgical instrument I, as shown in  FIGS. 15 and 16 , employed to manipulate vertebrae L4, L5. Surgical instrument I includes extender pedicles screws  70 , which are attached with vertebrae L4, L5 to manipulate vertebrae L4, L5. Surgical instrument I manipulates vertebrae L4, L5 such that endplate surfaces E 1 , E 2  exert a compressive force on interbody cage  312  such that interbody cage  312  comprises a fulcrum during compression and screws  32  are movable to one or a plurality of axial orientations in a first configuration, as described herein. As such, surgical instrument I manipulates vertebrae L4, L5 to rotate vertebrae L4, L5, to achieve segmental lordosis of vertebrae L4, L5 as determined by angle α 2  and locks screws  32  and interbody cage  312  in a fixed configuration with vertebrae L4, L5. 
     In one embodiment, as shown in  FIG. 17 , spinal implant system  10 , similar to the systems and methods described herein, comprises an interbody cage  412 , similar to interbody cage  312  described herein. The components of interbody cage  412  are delivered via a lateral surgical pathway to the surgical site and include a plurality of bone screws  32 , as described herein, fastened with an L4 vertebral level and a plurality of bone screws  32  fastened with an L5 vertebral level. 
     Interbody cage  412  includes a plurality of spaced apart slots  430   a ,  430   b , similar to slot  330  described herein, which are aligned with vertebra L4 and oriented to receive bone screw  32 /crown  36  assemblies, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surfaces that define slots  430   a ,  430   b  in a first configuration, as described herein. Bone screws  32  disposed with slots  430   a ,  430   b  are engaged with tissue of vertebra L4 and rotatable to a plurality of axial orientations in a selected angular range relative to its axis and crown  36 . Bone screws  32  abut and/or frictionally engage crowns  36  of slots  430   a ,  430   b  to resist and/or prevent backout of bone screws  32  from tissue of vertebra L4 and/or interbody cage  412 . 
     Interbody cage  412  includes a plurality of spaced apart slots  440   a ,  440   b , similar to slot  340  described herein, which are aligned with vertebra L5 and oriented to receive bone screw  32 /crown  36  assemblies, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surfaces that define slots  440   a ,  440   b  in a first configuration, as described herein. Bone screws  32  disposed with slots  440   a ,  440   b  are engaged with tissue of vertebra L5 and rotatable to a plurality of axial orientations in a selected angular range relative to its axis and crown  36 . Bone screws  32  abut and/or frictionally engage crowns  36  of slots  440   a ,  440   b  to resist and/or prevent backout of bone screws  32  from tissue of vertebra L5 and/or interbody cage  412 . 
     A surgical instrument I manipulates vertebrae L4, L5. Surgical instrument I includes extender pedicles screws  70 , which are attached with vertebrae L4, L5 to manipulate vertebrae L4, L5. Surgical instrument I manipulates vertebrae L4, L5 such that endplate surfaces of vertebrae L4, L5 exert a compressive force on interbody cage  412  such that interbody cage  412  comprises a fulcrum during compression and screws  32  are movable to one or a plurality of axial orientations in a first configuration, as described herein. As such, surgical instrument I manipulates vertebrae L4, L5 to rotate vertebrae L4, L5, to achieve segmental lordosis of vertebrae L4, L5 and locks screws  32  and interbody cage  412  in a fixed configuration with vertebrae L4, L5. 
     In one embodiment, as shown in  FIGS. 18-22 , spinal implant system  10 , similar to the systems and methods described herein, comprises an interbody cage  512 , similar to the interbody cages described herein. Interbody cage  512  extends between an anterior surface  514  and a posterior surface  516 . Anterior surface  514  is configured to face an anterior side of a body and be disposed adjacent to an anterior portion of vertebrae, such as, for example, an anterior portion of a cervical spine and intervertebral space between a C2 vertebra and a C3 vertebra of vertebrae V. Posterior surface  516  is configured to face a posterior side of a patient body and be disposed adjacent a posterior portion of vertebrae, such as, for example, a posterior portion of the C2-C3 intervertebral space. 
     Interbody cage  512  includes a surface  518  disposed at a selected angular orientation relative to a surface  520 , similar to surfaces  18 ,  20  described herein, to form interbody cage  512  for achieving segmental lordosis of one or more vertebra adjacent the C2-C3 intervertebral space, similar to that described herein. 
     Interbody cage  512  is selected such that surface  518  is disposed at a selected angular orientation relative to surface  520 , similar to that described herein. Pilot holes or the like are made in selected vertebra C2 and vertebra C3 of vertebrae adjacent the C2-C3 intervertebral space for receiving bone screws  32 . An inserter (not shown) is attached with interbody cage  512  to deliver interbody cage  512  adjacent to a surgical site for implantation adjacent the C2-C3 intervertebral space. Surface  518  engages endplate tissue of vertebra C2 and surface  320  is disposed facing endplate tissue of vertebra C3. 
     A slot  530 , similar to slot  30  described herein, is aligned with vertebra C2 and oriented to receive a bone screw  32 /crown  36  assembly, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  530  in a first configuration, as described herein. Bone screw  32  is engaged with tissue of vertebra C2. Bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in a selected angular range relative to its axis and crown  36 , similar to that described herein. Bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue of vertebra C2 and/or interbody cage  512 . 
     A slot  540 , similar to slot  40  described herein, is aligned with vertebra C3 and oriented to receive a bone screw  32 /crown  36  assembly, similar to that described herein. Crown  36  supports bone screw  32  and bone screw  32  slidably engages and/or translates relative to crown  36  and/or the surface that defines slot  540  in a first configuration, as described herein. Bone screw  32  is engaged with tissue of vertebra C3. Bone screw  32  is movable and/or rotatable to one or a plurality of axial orientations in a selected angular range relative to its axis and crown  36 . Bone screw  32  abuts and/or frictionally engages crown  36  to resist and/or prevent backout of bone screw  32  from tissue of vertebra C3 and/or interbody cage  512 . 
     Interbody cage  512  is disposed with vertebrae C2, C3 such that interbody cage  512  comprises a fulcrum between the endplate surfaces of vertebrae C2, C3. The endplate surfaces engage surfaces  518 ,  520  to achieve a selected segmental lordosis of vertebrae C2, C3. In some embodiments, the endplate surfaces engage surfaces  518 ,  520  such that bone screw  32  abuts and/or frictionally engages crown  36  to lock screws  32  and interbody cage  512  in a fixed configuration with vertebrae C2, C3. In some embodiments, as shown in  FIG. 23 , spinal implant system  10  includes a plurality of interbody cages  512  implanted with a plurality of intervertebral spaces between a plurality of vertebral levels of the cervical spine to treat a cervical kyphotic deformity with stand-alone instrumentation such that a kyphotic cervical spine is corrected to a selected lordotic cervical spine, as described herein. 
     In some embodiments, interbody cage  512  defines an opening, such as, for example, a spheroidal joint  550 , as shown in  FIG. 18 . Spheroidal joint  550  is oriented to receive a head  572  of a step bolt screw  570 . Spheroidal joint  550  supports head  572  and head  572  slidably engages the surfaces that define spheroidal joint  550  for relative movement therein in a first configuration, as described herein. 
     Step bolt screw  570  disposed with spheroidal joint  550  is rotatable to a plurality of axial orientations in a selected angular range relative to its axis and spheroidal joint  550 . In some embodiments, step bolt screw  570  abuts and/or frictionally engages the surfaces that define spheroidal joint  550  to resist and/or prevent backout of step bolt screw  570  from interbody cage  512 . In some embodiments, step bolt screw  570  abuts and/or frictionally engages the surfaces that define spheroidal joint  550  to lock step bolt screw  570  and interbody cage  512  in a fixed configuration with vertebrae C2, C3. In some embodiments, interbody cage  512  can include one or a plurality of spheroidal joints  550 , which may be aligned, co-axial, define a trajectory, arcuately oriented, offset, staggered, in series, parallel, transverse and/or spaced apart. Spheroidal joint  550  is disposed centrally between slot  530  and slot  540 , as shown in  FIG. 19 . 
     Interbody cage  512  includes a plate  560 , which has a substantially rectangular configuration. In some embodiments, plate  560  can be variously configured, such as, for example, tubular, oval, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, variable, hollow and/or tapered. Plate  560  includes a portion  562  configured to engage a vertebral level, such as, for example, vertebra C2 and a portion  564  configured to engage a vertebral level, such as, for example, vertebra C3, as shown in  FIG. 20 . In one embodiment, plate  560  may be attached with interbody cage  512  prior to implantation or in situ. 
     Plate  560  includes an opening  566  configured for disposal of step bolt screw  570  to connect plate  560  with interbody cage  512 . Step bolt screw  570  includes an elongated post  574  configured for disposal with opening  566 . Plate  560  is configured for translation and angulation along post  574  to facilitate orientation and engagement of plate  560  with vertebrae for fixing the components of interbody cage  512  with vertebrae. A nut  576  is threaded with step bolt screw  570  to lock plate  560  with interbody cage  512  to fix the components of interbody cage  512  with vertebrae. In some embodiments, as shown in  FIG. 24 , spinal implant system  10  includes a plurality of interbody cages  512  and a plate  560  that extends over a plurality of vertebral levels. Interbody cages  512  are implanted with a plurality of intervertebral spaces between a plurality of vertebral levels of the cervical spine and plate  560  is connected with the plurality of vertebral levels to treat a cervical kyphotic deformity with stand-alone instrumentation such that a kyphotic cervical spine is corrected to a selected lordotic cervical spine, as described herein. 
     It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.