Abstract:
A spine stabilization and fusion system includes a lateral cage and a lateral block plate. The lateral cage is configured to be placed between an upper vertebra and a lower vertebra, and a face of the lateral cage includes one or more first holes configured to receive fasteners and a first shaft bore configured to receive a shaft. The lateral block plate includes one or more second holes extending from a lateral face of the lateral block plate to a medial face of the lateral block plate and configured to receive the fasteners. The one or more second holes are configured to align with the one or more first holes of the lateral cage. The lateral block plate also includes a second shaft bore configured to receive the shaft, where the second shaft bore is configured to align with the first shaft bore of the lateral cage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the priority benefit of U.S. Provisional App. No. 62/235,643 filed on Oct. 1, 2015, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Lumbar spine fusion, or arthrodesis, is a surgical procedure that is performed to fuse two or more vertebrae together. During the procedure, a surgeon places a bone graft or other biological and/or scaffold material that is intended to promote new bone growth between two or more vertebrae. One form of fusion involves removing the majority of the intervertebral disk and replacing the disk with a structural cage that holds bone graft or other material. The spine segments being fused may be stabilized with spinal instrumentation such as a plate and screws. This type of fusion can be performed through a direct lateral or anterolateral retroperitoneal surgical approach. Spinal fusion surgery can be used to relieve nerve generated pain, and to treat ailments such as lumbar degenerative disk disease, spinal stenosis, lumbar spondylolisthesis, and scoliosis. 
       SUMMARY 
       [0003]    An illustrative spine stabilization and fusion system includes a lateral cage and a lateral block plate. The lateral cage is configured to be placed between an upper vertebra and a lower vertebra, and a face of the lateral cage includes one or more first holes configured to receive fasteners and a first shaft bore configured to receive a shaft. The lateral block plate includes one or more second holes extending from a lateral face of the lateral block plate to a medial face of the lateral block plate and configured to receive the fasteners. The one or more second holes are configured to align with the one or more first holes of the lateral cage. The lateral block plate also includes a second shaft bore configured to receive the shaft, where the second shaft bore is configured to align with the first shaft bore of the lateral cage. 
         [0004]    A method for spine stabilization and fusion includes placing a lateral cage into a disk space between an upper vertebra and a lower vertebra. A face of the lateral cage includes one or more first holes configured to receive fasteners and a first shaft bore configured to receive a shaft. The method also includes placing a lateral block plate adjacent to the lateral cage. The lateral block plate includes one or more second holes extending from a lateral face of the lateral block plate to a medial face of the lateral block plate and configured to receive the fasteners. The lateral block plate also includes a second shaft bore configured to receive the shaft. The method further includes placing the fasteners through the one or more second holes of the lateral block plate, through the one or more first holes of the lateral cage, and into endplates of the upper vertebra and the lower vertebra. 
         [0005]    The foregoing is a summary of the disclosure and thus by necessity contains simplifications, generalizations, and omissions of detail. Consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, features, and advantages of the devices and/or processes described herein, as defined by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIGS. 1A-1C  depict a lateral block plate in accordance with an illustrative embodiment. 
           [0007]      FIG. 2  depicts a lateral cage in accordance with an illustrative embodiment. 
           [0008]      FIG. 3A  depicts an insertion handle, a lateral block plate, and a lateral cage in a disassembled configuration in accordance with an illustrative embodiment. 
           [0009]      FIG. 3B  depicts an insertion handle, a lateral block plate, and a lateral cage in an assembled configuration in accordance with an illustrative embodiment. 
           [0010]      FIG. 3C  depicts an insertion handle, a lateral block plate, and a lateral cage in an assembled configuration, with screws placed through and engaging the lateral block plate and passing freely through a wall of the lateral cage, in accordance with an illustrative embodiment. 
           [0011]      FIG. 4A  depicts a front view of a lateral block plate and a lateral cage with screws placed through and engaging the lateral block plate and passing freely through a side wall of the lateral cage, in accordance with an illustrative embodiment. 
           [0012]      FIG. 4B  is a frontal cross sectional view of a lateral block plate and a lateral cage with screws placed through a lateral cage and passing freely through a side wall of the lateral cage, with a screw head engaging the lateral block plate, in accordance with an illustrative embodiment. 
           [0013]      FIGS. 4C and 4D  are angled and top views, respectively, of a lateral block plate and screws adjacent to a lateral cage as depicted in  FIG. 4A . 
           [0014]      FIG. 5A  depicts a side view of a lateral plate in accordance with an illustrative embodiment. 
           [0015]      FIG. 5B  depicts an angled view of a lateral block plate and screws adjacent to a lateral cage, as well as a lateral plate that is attached to the lateral block plate with a bolt, in accordance with an illustrative embodiment. 
           [0016]      FIGS. 5C and 5D  depict a side view of a lateral block plate and screws adjacent to a lateral cage, as well as a lateral plate that is attached to the lateral block plate, in accordance with an illustrative embodiment.  FIG. 5B  shows a lateral plate in a straight configuration, whereas  FIG. 5C  shows a lateral plate in an angled configuration. 
           [0017]      FIGS. 6A-6C  depict a front view, a top view, and an angled view, respectively, of a lateral block plate and screws adjacent to a lateral cage, as well as a lateral plate that is attached to a lateral block plate, with screws now placed through and engaging the lateral plate, in accordance with an illustrative embodiment. 
           [0018]      FIG. 6D  depicts a front view of a lateral cage with a lateral plate, without the lateral block plate, with screws engaging the lateral plate, in accordance with an illustrative embodiment. 
           [0019]      FIGS. 7A-7C  depict a front view and two angled views showing the lateral sides of the of a lateral block plate with screws, in accordance with an illustrative embodiment. 
           [0020]      FIGS. 8A-8C  depict a front view and two angled views showing the lateral sides of a lateral plate attached to a lateral block plate with screws engaging both plates, in accordance with an illustrative embodiment. 
           [0021]      FIG. 9  depicts a front view of a spine segment with a vertebral body above and below a disk space, with the disk space occupied by the lateral block plate and screws adjacent to a lateral cage, as well as a lateral plate and screws, with the screws secured to the vertebral bodies, in accordance with an illustrative embodiment. 
           [0022]      FIGS. 10A and 10B  depict a side view and a top view, respectively, of a lateral block plate and a lateral plate and screws adjacent to a lateral cage, with lines drawn to indicate cross sectional planes depicted in  FIGS. 10C and 10D , in accordance with an illustrative embodiment. 
           [0023]      FIG. 11  is a flow diagram depicting a process for performing a lumbar spine fusion with a lateral block plate and/or a lateral plate in accordance with an illustrative embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the subject matter described herein. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the described subject matter, since the scope of the subject matter is best defined by the appended claims. 
         [0025]    Spinal fusion procedures can be performed via several different approaches, including the lateral retroperitoneal approach or anterolateral retroperitoneal approach. Regardless of the approach used, traditional interbody spinal fusion procedures involve removal and replacement of an intervertebral disk with a cage that is used to provide structural support to the patient in place of the removed disk. The cage usually holds bone graft or other material that promotes a bony fusion, and typically fills some or all of the space that was previously occupied by the removed disk. The cage may be held in place and stabilized by a plate that is mounted outside of the disk space in a vertical position that is substantially perpendicular to both the disk space and the cage. The plate is secured by screws bored into the lateral sides of vertebral bodies above and below the disk space. As such, in traditional procedures, the plate is mounted to the sides of the vertebrae and sits outside the disk space with the screws penetrating the lateral vertebral body cortex, as opposed to sitting partially or completely within the disk space with the screws penetrating the endplates of the vertebrae. 
         [0026]    Such spinal fusion techniques are prone to several problems due in part to the position in which the plate is mounted to the vertebral bodies. The psoas muscle and lumbar nerve plexus both run along the lateral sides of the vertebral bodies in the lumbar portion of the spine, making it difficult for the surgeon to properly place the vertical plate without interfering with one or both of the psoas muscle and the lumbar nerve complex. It can be difficult to hold the plate in position on the vertebral body while drilling the screw holes, as the force of the drill guide and the action of the drill on the hard vertebral bone have a tendency to cause the plate to migrate cephalad or caudal during drilling. Additionally, even when the surgeon is able to successfully place the plate, conventional plates may be prominent and can cause irritation to the psoas muscle and/or the lumbar nerve plexus. Another issue is the presence of pedicle screws in the vertebral body below or caudal to the fusion in cases where a patient has had a previous instrumented spinal fusion and now has developed adjacent segment deterioration above or cephalad to the previous fusion. In this situation it can be difficult to place a screw through a plate because the new screw trajectory often overlaps with the existing screw, and the surgeon is forced to place a longer plate than desired in order to allow for new screw placement below or cephalad to the existing screws. In view of these problems, the inventor has designed a new system that utilizes a cage in conjunction with a plate that may be positioned entirely or predominantly within the disk space. Additionally, the new system uses a plate or plates that are initially attached to the cage, which holds the plate or plates firmly in position so there is no plate movement during drilling, and then the plate or plates are detached from the cage to allow for separate biomechanical forces on the cages and plate or plates during patient activity. 
         [0027]    Broadly, the embodiments described herein provide a spinal fusion plate that may be placed within the intervertebral space along with a cage in lateral and anterolateral spinal fusion procedures. Another lateral plate can be attached to the intervertebral plate, or can be used primarily, to provide additional options of achieving spinal stability. The spinal plates described herein solve the problems of traditional systems with plate placement and plate prominence and screw placement above a previous instrumented fusion because it can sit within the disk space, rather than outside the disk space. The system also solves the problem of plate migration during drilling because the plate or plates are initially attached to the lateral cage during the drilling and screw placement process. 
         [0028]      FIG. 1A  depicts a lateral or side view of a lateral block plate  100 , in accordance with an illustrative embodiment. It is called a lateral block plate because in at least one embodiment it is shaped like a rectangular block. The lateral block plate  100  may be provided in different heights, such as in 1 millimeter (mm) increments starting at approximately 5 mm up to about 20 mm, depending on the thickness of the cage and the vertical dimensions of the intervertebral space to be filled. The lateral block plate  100  may have the same height anteriorly and posteriorly, or it can be configured to be taller anteriorly than posteriorly, thus reproducing or restoring a patient&#39;s lumbar lordosis. The plate width (i.e., the distance between the most lateral aspect of the plate and the most medial aspect of the plate) is selected to be between about 3-8 mm, preferably on the order of 5 mm. The lateral block plate length (i.e., the distance between the most posterior aspect of the plate and the most anterior aspect of the plate) can depend on the width of the cage, the width of the vertebrae to be fused, and/or the number of screw holes (e.g., 2, 3, or 4) to be used to secure the lateral block plate, and may be between about 15 mm-25 mm, preferably on the order of 20 mm. In alternative embodiments, different dimensions may be used for the height, width, and/or length of the lateral block plate. The lateral block plate  100  can be made with various materials, including titanium, titanium alloy, polyether ether ketone (PEEK), or a carbon fiber/PEEK combination. These are all existing materials that are commonly used for the manufacture of implanted medical devices. The lateral block plate is manufactured using existing manufacturing methods and standards that are currently used in the manufacture of medical implants. It should be understood, of course, that the foregoing relates to exemplary embodiments and that modifications may be made without departing from the spirit and scope of the invention as set forth in the claims. 
         [0029]    Holes  105  and  110  accommodate screws or fasteners that pass through the lateral block plate  100  to secure it to bone. In an alternative embodiment, a lateral block plate may include more than two holes to accommodate screws or fasteners. In an illustrative embodiment, hole  105  is angled upwards between 10 and 25 degrees and hole  110  is angled downwards between 10 and 25 degrees. In alternative embodiments, different angles may be used for the holes  105  and  110 . Holes  105  and  110  are tapered to allow for passage of a threaded screw shaft (shown later) through the plate with screw head engagement of the plate without the screw head being prominent. Hole  120  is threaded and accommodates an insertion handle or a bolt to attach a lateral plate (shown later) to a lateral block plate  100 . In an alternative embodiment, hole  120  may not be threaded, but may be designed to accommodate a fastener that will attach to a lateral plate (shown later). 
         [0030]      FIG. 1B  depicts a back side view of a lateral surface of a lateral block plate  100 , in accordance with an illustrative embodiment. Holes  105  and  110  accommodate screws or fasteners that pass through the lateral block plate to secure it to bone. Hole  105  is angled upwards between 10 and 25 degrees and hole  110  is angled downwards between 10 and 25 degrees. Hole  120  is threaded and accommodates an insertion handle or a bolt to attach a lateral plate to the lateral block plate. In an alternative embodiment, hole  120  may not be threaded, but may be designed to accommodate a fastener that will attach to a lateral plate (shown later).  FIG. 1C  depicts an angled view of a lateral block plate  100 , in accordance with an illustrative embodiment. Holes  105  and  110  accommodate screws or fasteners that pass through the lateral block plate to secure it to bone. Hole  105  is angled upwards between 10 and 25 degrees and hole  110  is angled downwards between 10 and 25 degrees. Hole  120  is threaded and accommodates an insertion handle or a bolt to attach a lateral plate to the lateral block plate. In an alternative embodiment, hole  120  may not be threaded, but may be designed to accommodate a fastener that will attach to a lateral plate (shown later). 
         [0031]      FIG. 2  depicts an angled view of a structural fusion cage  200 , also called a lateral cage  200 , that is designed to be inserted into the intervertebral space after a discectomy is performed via a retroperitoneal direct lateral or anterolateral approach, in accordance with an illustrative embodiment. A lateral cage may be comprised of walls  205 ,  210 ,  215 ,  220 , and  225 , or in an alternative embodiment, may be compromised of more or fewer walls. Wall  215  is the leading edge of the lateral cage  200 , in that it is inserted first into the disk space, and faces laterally, opposite the surgical wound. Wall  205  is opposite wall  215  and faces lateral towards the surgical wound and is the only visible part of the cage to the surgeon once it is inserted in the disk space. As an example, if cage  200  was inserted via a right-sided direct lateral surgical approach, wall  215  would be the leading edge of insertion and would therefore face the left side of the patient&#39;s body, and wall  205  would face the right side of the patient&#39;s body, and would be visible from the surgical wound. While the dimensions of the cage may vary, it is estimated that the height will vary between approximately 6 mm and 20 mm, the length (the distance from wall  205  to wall  215 , inclusive) will vary between approximately 35 mm and 60 mm, and the width (the distance from wall  210  to  220 , inclusive) will vary between approximately 15 mm and 25 mm. Hole  260  is threaded and accommodates an insertion handle or a bolt to attach a lateral plate (shown later) to the lateral block plate. In an alternative embodiment, hole  260  may not be threaded, but may be designed to accommodate a fastener that will attach to a lateral plate (shown later). Holes  250  are designed to allow free passage of screws or fasteners that will be placed through a lateral block plate  100  to secure a lateral block plate  100  to a vertebral body or bodies. In an alternative embodiment, holes  250  may be located eccentrically in a cephalad or caudal direction in wall  205 , such that holes  250  are completely open in a cephalad or caudal direction, to allow for free passage of screws or fasteners. 
         [0032]      FIG. 3A  depicts a disassembled angled view of the lateral cage  200 , the lateral block plate  100 , and an insertion handle  300 , in accordance with an illustrative embodiment. Insertion handle  300  has a threaded leading end  305  that threads into lateral block plate  100  through threaded hole  120  and through lateral cage  200  through threaded hole  260 . Insertion handle  300  has a shaft portion  310  of variable length and a back end  315  of variable configuration. Alternative embodiments of insertion handle  300  could have a variety of mechanisms to connect to lateral block plate  100  and lateral cage  200  rather than through a threaded terminal end  305  and threaded holes  120  and  260 . 
         [0033]      FIG. 3B  depicts an assembled angled view of a lateral cage  200 , a lateral block plate  100 , and an insertion handle  300 , in accordance with an illustrative embodiment. The lateral block plate  100  is securely held to lateral cage  200  through their connection to insertion handle  300 , and can now be inserted into an intervertebral disk space as part of the fusion operation. Once inserted into the intervertebral disk space, screws  350  with a threaded shaft portion  360  and head portion  370  can be placed through lateral block plate  100  and lateral cage  200  to engage the vertebral bodies above and below the lateral cage  200 , as depicted in  FIG. 3C . The screw threaded shaft portion  360  will pass freely through the holes  105  and  110  (not shown here, shown in  FIGS. 1A-1C ) in the lateral block plate  100  and through the holes  250  (not shown) in the lateral cage  200 , whereas the screw head portion  370  when fully inserted will engage the lateral block plate  100  and securely hold the lateral block plate  100  in place in the intervertebral space (shown later). In an alternative embodiment, fasteners other than screws  350  may be used to secure the lateral block plate  100  and the lateral cage  200  to the vertebral bodies. 
         [0034]      FIG. 4A  depicts a front view of the lateral block plate  100  and the lateral cage  200  with screws  350  placed through and engaging the lateral block plate  100  and passing freely through a side wall of the lateral cage  200 , in accordance with an illustrative embodiment. Screws  350  are inserted into the vertebral bodies above and below the disk space being fused. Screws  350  are approximately 4 mm to 6 mm in diameter and between 20 mm and 60 mm in length. Provided the lateral block plate  100  is seated entirely or partially within the disk space, screws  350  enter the endplates of the vertebral bodies above and below the disk space being fused and are anchored in the cancellous vertebral body bone. If the lateral block plate is positioned more lateral, screws  350  may enter the lateral cortex of the vertebral bodies above and below the disk space being fused. The screw pathways may be established with a drill or an awl prior to insertion of screws  350 . The rigid connection of the lateral block plate to the lateral cage via the insertion handle (not shown) prevents cage migration during screw pathway drilling and screw placement. In an alternative embodiment, fasteners other than screws may be used to secure a lateral block plate  100  to a vertebral body. Insertion handle  300  (not shown) has been removed after screw insertion. 
         [0035]      FIG. 4B  is a frontal cross sectional view of a lateral block plate  100  and a lateral cage  200  with screw  350  placed through hole  110  in lateral block plate  100  and passing freely through hole  250  in a side wall of lateral cage  200 , in accordance with an illustrative embodiment. Screw  350  is comprised of a threaded shaft portion  360  and a head portion  370 . Hole  110  is tapered and has a larger diameter portion  155  that accommodates head portion  370 , allowing the head portion  370  to seat fully or nearly-fully within lateral block plate  100  once inserted; and hole  110  has a smaller diameter portion  150  that is slightly larger than and allows free passage of threaded shaft portion  360  but is smaller than head portion  370 . When screw  350  is inserted fully, head portion  370  tightly presses up against the smaller diameter portion  150  of hole  110 , this securing the lateral block plate  100  to bone.  FIG. 4C  is an angled view of a lateral block plate  100  and screws  350  with screw heads  370  and threaded screw shafts  360 , with the lateral block plate  100  adjacent to a lateral cage  200  as depicted in  FIG. 4A  and  FIG. 4B , in accordance with an illustrative embodiment.  FIG. 4D  is top view of a lateral block plate  100  and screws  350  adjacent to a lateral cage  200  as depicted in  FIGS. 4A and 4B , in accordance with an illustrative embodiment. 
         [0036]      FIG. 5A  depicts a side view of a lateral plate  500  with a tapered waist  525  and with a central hole  510  and eccentric holes  520 , in accordance with an illustrative embodiment. Holes  520  allow for bone screws or fasteners to be placed for securing the lateral plate to bone. Central hole  510  allows for passage of a threaded bolt ( 550  shown in  FIG. 5B ) to connect the lateral plate  500  to a lateral block plate, or to allow for an insertion handle (shown in  FIGS. 3A-3B ) to engage a lateral plate  500 , a lateral block plate  100 , and a lateral cage  200  (shown in  FIG. 5B ) such that they can be inserted as a single unit prior to screw placement. Another option is for the surgeon to engage a lateral plate  500  with an insertion handle in order to hold it rigidly in place during screw pathway drilling and screw placement. In an alternative embodiment, a lateral plate  500  may not have a tapered waist and so may be shaped in a more rectangular manner and may include 3, 4, or more holes to accommodate bone screws or fasteners, and may be secured to a lateral block plate by a mechanism other than a bolt. The lateral plate  500  can be made with various materials, including titanium, titanium alloy, polyether ether ketone (PEEK), or a carbon fiber/PEEK combination. These are all existing materials that are commonly used for the manufacture of implanted medical devices. The lateral plate is manufactured using existing manufacturing methods and standards that are currently used in the manufacture of medical implants. It should be understood, of course, that the foregoing relates to exemplary embodiments and that modifications may be made without departing from the spirit and scope of the invention as set forth in the claims. 
         [0037]      FIG. 5B  depicts an angled view of the lateral block plate  100  and screws  350  adjacent to the lateral cage  200  as well as a lateral plate  500  that is attached to the lateral block plate  100  via bolt  550 , in accordance with an illustrative embodiment. Bolt  550  is an optional feature that can be passed through central hole  510  as depicted in  FIG. 5A , and would be placed after removal of the insertion handle (not shown) per the surgeon&#39;s discretion. Bolt  550 , if used, would mate the lateral plate  500  to the lateral block plate  100  but would not mate to the lateral cage  200 . In an alternative embodiment, the bolt  550  can also be used to mate the lateral plate  500  to the lateral block plate  100  and to the lateral cage  200 .  FIGS. 5C and 5D  depict a side view of the lateral block plate  100  and screws  350  adjacent to the lateral cage  200 , as well as the lateral plate  500  that is attached to the lateral block plate  100  via bolt  550 , in accordance with illustrative embodiments.  FIG. 5C  shows a side view of the lateral plate  500  in a straight configuration, whereas  FIG. 5D  shows a side view of the lateral plate  500  in a rotated configuration. The lateral plate  500  can be placed and rotated at any angle with respect to lateral block plate  100 , provided the screw pathway does not overlap with the face of the lateral block plate. When the lateral plate  500  is positioned straight as in  FIG. 5C , if the plate is designed with a tapered waist as depicted in  FIGS. 5A and 5C , the screws  350  can be placed or accessed with the lateral plate  500  in place. The lateral plate  500  could then be rotated as depicted in  FIG. 5D . When the lateral plate  500  is positioned rotated as in  FIG. 5D , if the plate is designed with a tapered waist as depicted in  FIG. 5A , the screws  350  are held in a locked position in that they are prevented from backing out due to the overlapping of plate  500  with the screw heads of screws  350 . 
         [0038]      FIG. 6A  depicts a front view of the lateral block plate  100  with screws  350  adjacent to the lateral cage  200 , as well as the lateral plate  500  that is attached to the lateral block plate  100  via bolt  550 , with screws  650  now passing through and engaging the lateral plate  500 , in accordance with an illustrative embodiment. Screws  650  have the same general configuration as screws  350 , with a threaded shaft  360  as depicted in  FIG. 4B  and a screw head  370  that engages a plate as depicted in  FIGS. 4B and 4C . Though similar in configuration, screws  650  are separately identified from screws  350  in this description to distinguish them from screws  350 . The primary difference between screws  650  and screws  350  is that screws  350  pass through and engage via the screw head the lateral block plate  100  whereas screws  650  pass through and engage via the screw head the lateral plate  500 . Hence in this description, the fundamental difference between the screw  350  and the screw  650  is not necessarily the physical dimensions of the screw, but the plate with which they are associated. Screws  350  are associated with the lateral block plate  100  and screws  650  are associated with the lateral plate  500 . Screws  350  and screws  650  may have different dimensions depending on surgeon preference.  FIG. 6B  depicts a top view and  FIG. 6C  depicts an angled view of the lateral block plate  100  with screws  350  adjacent to the lateral cage  200 , as well as the lateral plate  500  that is attached to the lateral block plate  100  via bolt  550 , with screws  650  now passing through and engaging the lateral plate  500 , in accordance with illustrative embodiments. 
         [0039]      FIG. 6D  depicts a front view of the lateral plate  500  adjacent to the lateral cage  200  with screws  650  passing through and engaging the lateral plate  500 , in accordance with an illustrative embodiment. In an alternative embodiment, lateral plate  500  could be designed to accommodate more than two screws  650 , the most common configuration likely being a total of four screws. In the configuration depicted in  FIG. 6D , the surgeon has elected to not use a lateral block plate  100  as seen in  FIGS. 6A-6C . The lateral plate  500  is initially secured to the lateral cage  200  via an insertion handle (not shown) in a manner similar to the assembly steps depicted in  FIGS. 3A-3C , except in the method used as depicted in  FIG. 6D  the insertion handle engages the lateral plate  500  and the lateral cage  200 , rather than engaging the lateral block plate  100  and the lateral cage  200  as depicted in  FIGS. 3A-3C . Once the lateral cage  200  is inserted into the intervertebral space as part of the spinal fusion and the lateral plate  500  rests against the lateral aspects of the vertebral bodies above and below the disk space, the lateral plate  500  is held rigidly in position by virtue of the firm connection of the insertion handle (not shown) to the lateral plate  500  and the lateral cage  200 , and the screw holes can be drilled. The advantage to this configuration is the rigid connection of the lateral plate  500  to the lateral cage  200 , which due to the lateral cage being firmly seated within the disk space and with further control imparted by the insertion handle, prevents any movement or migration of the plate during screw pathway drilling and screw insertion. In one embodiment, a drill guide can be designed to mate with the insertion handle and rest against the plate, allowing for ease of drilling for the screws. Once screws  650  are placed into the vertebral bodies, the insertion handle (not shown) is removed, thereby completely disengaging a lateral plate  500  from the lateral cage  200 , allowing the lateral plate  500  and the lateral cage  200  to be subject to separate biomechanical forces as the spinal column is loaded during patient activity. 
         [0040]      FIG. 7A  depicts a front view of the lateral block plate  100  with screws  350 , in accordance with an illustrative embodiment.  FIGS. 7B and 7C  depict angled views of the lateral block plate  100  with screws  350 , in accordance with illustrative embodiments. Lateral block plate  100  in  FIGS. 7A-7C  is depicted without the lateral cage  200  or lateral plate  500  as seen in  FIGS. 6A-6C . 
         [0041]      FIG. 8A  depicts a front view of the lateral plate  500  attached to the lateral block plate  100  via bolt  550  with screws  650  placed through and engaging the lateral plate  500  and screws  350  placed through and engaging the lateral block plate  100 , in accordance with an illustrative embodiment.  FIGS. 8B and 8C  depict angled views of the lateral plate  500  attached to the lateral block plate  100  via bolt  550  (not shown in  FIG. 8B ) with screws  650  placed through and engaging lateral plate  500  and screws  350  placed through and engaging lateral block plate  100 , in accordance with illustrative embodiments. Lateral block plate  100  and lateral plate  500  in  FIGS. 8A-8C  are depicted without the lateral cage  200  as seen in  FIGS. 6A-6C . 
         [0042]      FIG. 9  depicts a front view of the lateral block plate  100  with associated screws  350  and the lateral plate  500  with associated screws  650  adjacent to the lateral cage  200  ( 950  collectively, as shown in  FIG. 6A ) after insertion into disk space  925  between vertebrae  900  and  905 , in accordance with an illustrative embodiment. Vertebrae  900  is above or cephalad to the disk space and includes vertebral body  901  and pedicles  910  and  911  and spinous process  915 . Vertebrae  905  is below or caudal to the disk space and includes vertebral body  906  and pedicles  912  and  913  and spinous process  915 . The screw  350  inserted into vertebral body  906  passes above or cephalad to pedicle  912 , so will pass above or cephalad to a pedicle screw (not shown) that would occupy pedicle  912  from a previous instrumented spinal fusion. The length of screw  350  can be selected to stop short of pedicle  913  if it is occupied with a pedicle screw (not shown) from a previous instrumented spinal fusion. The screw  650  may also be placed in a manner as to avoid a screw occupying pedicle  912 . 
         [0043]      FIG. 10A  depicts a side view of the lateral block plate  100  and lateral plate  500  and screws  350 , and screw heads  370  of screws  650  (screws  650  not visible due to the angle of view), with lines  1000  and  1001  drawn to indicate cross sectional planes depicted in  FIGS. 10C and 10CD  respectively, in accordance with illustrative embodiments.  FIG. 10B  depicts a top view of the lateral block plate  100  with associated screw  350  and the lateral plate  500  with associated screw  650 , with lines  1000  and  1001  drawn to indicate cross sectional planes depicted in  FIGS. 10C and 10CD  respectively, in accordance with illustrative embodiments. In  FIG. 10B , screws  650  and  350  overlap, so only a single screw of each  350  and  650  are visible, though there are four screws present as depicted in  FIG. 10A .  FIG. 10C  depicts a cross sectional image through plane  1000  (as shown in  FIGS. 10A and 10B ) of the lateral cage  200  inserted in a disk space  925  between a vertebrae  900  and a vertebrae  905 , with the lateral block plate  100  and the lateral plate  500 , in accordance with an illustrative embodiment. The lateral block plate  100  can sit entirely or partially within the disk space  925 , or can be positioned outside and lateral to the disk space  925 , whereas the lateral plate  500  is always positioned entirely outside a disk space  925 . The screw  350  passes through the lateral block plate  100  and lateral cage  200  and is inserted into a vertebral body  901 , with the screw head of a screw  350  engaging the lateral block plate  100 , thus securing the lateral block plate  100  firmly to the vertebral body  901 . The screw  650  passes through the lateral plate  500  and is inserted into the vertebral body  906 , with the screw head of the screw  650  engaging the lateral plate  500 , thus securing the lateral plate  500  firmly to the vertebral body  906 .  FIG. 10D  depicts a cross sectional image through plane  1001  (as shown in  FIGS. 10A and 10B ) of the lateral cage  200  inserted in the disk space  925  between the vertebrae  900  and the vertebrae  905 , with the lateral block plate  100  and the lateral plate  500 , in accordance with an illustrative embodiment. The screw  350  passes through the lateral block plate  100  and the lateral cage  200  and is inserted into the vertebral body  906 , with the screw head of the screw  350  engaging the lateral block plate  100 , thus securing the lateral block plate  100  firmly to the vertebral body  906 . The screw  650  passes through the lateral plate  500  and is inserted into the vertebral body  901 , with the screw head of the screw  650  engaging the lateral plate  500 , thus securing the lateral plate  500  firmly to the vertebral body  901 . 
         [0044]      FIG. 11  is a flow diagram depicting a process for performing a lumbar spine fusion in accordance with an illustrative embodiment. In alternative embodiments, fewer, additional, and/or different operations may be performed. Additionally, the use of a flow diagram is not meant to be limiting with respect to the order of operations performed. 
         [0045]    In an operation  1100 , the surgeon makes an incision and performs a retroperitoneal anterolateral or direct lateral approach to access the disk space to be fused in a manner well known to those skilled in the art. 
         [0046]    In an operation  1105 , the surgeon performs a lateral or anterolateral lumbar discectomy in a manner well known to those skilled in the art, in preparation for performing a fusion. 
         [0047]    In an operation  1110 , a lateral cage is attached to a lateral block plate via an insertion handle and is inserted into the disk space being fused. In illustrative embodiments, the disassembled lateral cage and lateral block plate and insertion handle are described with reference to  FIG. 3A , and the assembled lateral cage and lateral block plate and insertion handle are described with reference to  FIG. 3B . 
         [0048]    In an operation  1115 , the surgeon drills screw holes and places screws through the lateral block plate into the vertebral bodies above and below the disk space being fused. In an illustrative embodiment, the lateral block plate with screws are described with reference to  FIG. 3C . 
         [0049]    In an operation  1120 , the surgeon removes the insertion handle, thus disengaging the lateral block plate from the lateral cage. This could be the conclusion of the fusion operation, or optionally depending on surgeon discretion in an operation  1125 , the surgeon may now attach a lateral plate to the lateral block plate with a bolt. This holds the lateral plate rigidly in place to prevent plate migration during subsequent drilling of the screw holes and screw placement. Alternatively the surgeon could use an insertion handle to hold the lateral plate rigidly in place during screw pathway drilling. In an illustrative embodiment, the lateral block plate with screws through and engaging the lateral block plate, as well as the adjacent unattached lateral cage, are described with reference to  FIGS. 5B-5D . Screws can now be placed through the lateral plate into the vertebral bodies above and below the disk level to be fused. In an illustrative embodiment, the lateral block plate with screws through and engaging the lateral block plate, and the lateral plate with screws through and engaging the lateral plate, as well as the adjacent unattached lateral cage, are described with reference to  FIGS. 6A-6C  and  FIG. 9 . 
         [0050]    In an operation  1130 , if the surgeon has used both the lateral block plate and the lateral plate and they are attached via a bolt, the surgeon may choose to remove the bolt connecting the lateral block plate to the lateral plate, allowing the lateral block plate with associated screws and the lateral plate with associated screws to be exposed to separate biomechanical forces. The choice of leaving the bolt in place or removing it is based on the clinical circumstances and is up to the discretion of the surgeon. Once the lateral cage, lateral block plate and/or lateral plate, and screws are fully inserted, the surgeon then completes the operation by closing the wound in a manner well known to those skilled in the art. 
         [0051]    The components described herein can be made in a variety of lengths and/or shapes to accommodate various patient anatomies and surgeon preferences. The components can be made from stainless steel, titanium, titanium-alloy, cobalt-chrome, polyether ether ketone (PEEK), a carbon fiber/PEEK combination, or any suitable material that is able to withstand the biomechanical stresses under which they will be placed. 
         [0052]    The foregoing description of illustrative embodiments has been presented for purposes of illustration and of description. It is not intended to be exhaustive or limiting with respect to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosed embodiments. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.