Patent Publication Number: US-2016235448-A1

Title: Spinal plate selection and positioning system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/157,412, filed Jan. 16, 2014, which claims the benefit of U.S. Provisional Application No. 61/753,420, filed Jan. 16, 2013, entitled “SPINAL PLATE SELECTION AND POSITIONING SYSTEM,” which is hereby incorporated by reference herein in its entirety, including but not limited to those portions that specifically appear hereinafter, the incorporation by reference being made with the following exception: In the event that any portion of the above-referenced applications is inconsistent with this application, this application supercedes said above-referenced applications. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND 
     1. The Field of the Present Disclosure 
     The present disclosure relates generally to medical devices, and more particularly, but not necessarily entirely, to medical implants and instrumentation utilized in spinal-fusion surgical procedures. 
     2. Description of Related Art 
     Spinal fusion surgery is often performed to reduce pain caused by aging or injury. Spinal fusion surgery typically involves fusing two or more vertebrae in the spinal column. Fusion of the vertebrae may be accomplished using a bone fixation device, such as an interbody plate. In particular, rigid interbody plates may be secured to the vertebrae. The interbody plates may stabilize the spinal column. Fasteners, such as bone screws, may be utilized to secure the interbody plates to the vertebrae. For this reason, interbody plates are generally rigid but may have some adjustability for sizing purposes. Rods may sometimes also be utilized to provide greater stabilization. 
     It is further known to use an interbody cage in conjunction with a spinal fusion procedure. In particular, an interbody cage may be implanted by press fit into the disc space between two adjacent vertebrae. (This, of course, may first require removal of the patient&#39;s natural disc.) In this regard, the use of an interbody cage has been found to reduce post-operative discomfort and pain. Interbody cages may take a wide variety of forms. For example, interbody cages may be formed from alloys or plastic. In some instances, interbody cages are packed with autologous bone material in order to promote fusion. That is, this supplementary bone material, such as an allograft or an autograft, may be used in conjunction with the patient&#39;s natural bone growth process to fuse the vertebrae. In other instances, interbody cages may be made entirely of, or partly of, either a human graft (allograft or autograft) or an animal graft (xenograft). 
     An interbody plate and an interbody cage may be utilized together. In this instance, the interbody plate may extend over a disc space containing the interbody cage. The interbody plate may then be secured to the two vertebrae defining the disc space using fasteners. An interbody plate is ideally positioned parallel to the longitudinal axis of the spine and symmetrically over the disc space. In practice, however, proper alignment and positioning of the interbody cage may be difficult to accomplish due to (i) narrow wounds which obscure surgical landmarks; (ii) blood or other tissue may obscure landmarks; (iii) the interbody plate itself may obscure landmarks; (iv) drill guides that are used to drill pilot holes may further obscure landmarks; and (v) the interbody plate may move prior to being secured without the surgeon being aware. 
     In the past, some techniques have been developed in an attempt to properly align and position interbody plates and interbody cages. One technique includes the use of a trial cage connected to a drill guide. In particular, the trial cage is temporarily installed into the disc space. The attached drill guide is then utilized to drill pilot holes in the adjacent vertebrae. The trial cage and drill guide are then removed and the interbody cage is implanted into the disc space. The plate is then positioned and fastened to the vertebrae using the pilot holes. This technique, however, has limitations. One limitation is that there is no assurance that the trial cage and the actual interbody cage are located in the same position. Another limitation is that there is no assurance that the interbody plate is positioned correctly with respect to the pilot holes. A further limitation is that the positioning of the interbody cage relative to the interbody plate is not controlled. 
     Another attempt to properly align and position interbody plates and interbody cages is taught by Fraser et al. (U.S. Patent Publication No. 2011/004253). Fraser teaches the use of an interbody plate that includes integral mating elements that are adapted to slidably engage an interbody cage. One draw back to Fraser&#39;s teachings is that there is no assurance that the interbody plate is centered over the interbody cage or that the cage is properly positioned in the disc space prior to the plate being secured. 
     Despite the advantages of known alignment and positioning techniques, improvements are still being sought. For example, many of the prior art devices cannot assure that an interbody plate and interbody cage are ideally positioned. The prior art is thus characterized by several disadvantages that are addressed by the present disclosure. The present disclosure minimizes, and in some aspects eliminates, the above-mentioned failures, and other problems, by utilizing the methods and structural features described herein. 
     The features and advantages of the present disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the present disclosure without undue experimentation. The features and advantages of the present disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the disclosure will become apparent from a consideration of the subsequent detailed description presented in connection with the accompanying drawings in which: 
         FIG. 1  is a perspective view of an interbody cage according to an embodiment of the present disclosure; 
         FIG. 2  is a perspective view of a holding rod according to an embodiment of the present disclosure; 
         FIG. 3  is a perspective view of an interbody plate according to an embodiment of the present disclosure; 
         FIG. 4  is a perspective view of a guide member according to an embodiment of the present disclosure; 
         FIG. 5  is a perspective view of a drill guide according to an embodiment of the present disclosure; 
         FIG. 6  is another perspective view of the drill guide shown in  FIG. 5  according to an embodiment of the present disclosure; 
         FIG. 7  is a perspective view of another drill according to an embodiment of the present disclosure; 
         FIG. 8  is an exploded view of an assembly according to an embodiment of the present disclosure; 
         FIG. 9  is a partially exploded view of the assembly shown in  FIG. 8  according to an embodiment of the present disclosure; 
         FIG. 10  depicts a procedure for installing an interbody cage in a disc space according to an embodiment of the present disclosure; 
         FIG. 11  depicts a procedure for drilling pilot holes and installing plate fasteners in a vertebra according to an embodiment of the present disclosure; 
         FIG. 12  depicts a procedure for drilling pilot holes and installing plate fasteners in a vertebra according to an embodiment of the present disclosure; 
         FIG. 13  depicts a procedure for removing a drill guide according to an embodiment of the present disclosure; 
         FIG. 14  depicts an installed interbody plate and interbody cage according to an embodiment of the present disclosure; and 
         FIG. 15  depicts a pair of installed interbody plates and interbody cages according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     For the purposes of promoting an understanding of the principles in accordance with the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the disclosure as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the disclosure claimed. 
     In describing and claiming the present disclosure, the following terminology will be used in accordance with the definitions set out below. It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. As used herein, the terms “comprising,” “including,” “containing,” “characterized by,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps. 
     Applicant has discovered a spinal plate selection and positioning system for use in a spinal fusion surgery. In an embodiment, the system may include a guide member removably attached to an interbody cage by a holding rod. After the interbody cage has been installed into a disc space defined between a first vertebra and a second vertebra using the holding rod, the guide member may be utilized to align and position an interbody plate over the disc space. The guide member may center the interbody plate over the interbody cage and also prevent the interbody plate from rotating about a longitudinal axis of the guide member. Thus, the guide member may align and position the interbody plate with reference to the interbody cage since the guide member and interbody cage are coupled. 
     A drill guide may then also be aligned and positioned over the disc space using the guide member. Pilot holes may then be drilled in the vertebrae defining the disc space using the drill guide. Using the drill guide, fasteners may be installed to secure the interbody plate to the vertebrae. The drill guide may then be removed from the guide member and the guide member may be detached from the interbody cage, now secured in the disc space beneath the interbody plate. 
     Referring now to  FIG. 1 , there is depicted an exemplary interbody cage  100  pursuant to an embodiment of the present disclosure. The interbody cage  100  may include a body member  102 . The body member  102  may have a superior surface  104  and an inferior surface  105  (not explicitly visible in  FIG. 1 , but understood to be opposite of the superior surface  104 ). A sidewall  106  may circumscribe the body member  102 . The sidewall  106  may extend between the superior surface  104  and the inferior surface  105 . The sidewall  106  may define, for the body member  102 , a proximal surface  108  and a distal surface  110  (not explicitly visible in  FIG. 1 , but understood to be opposite of the proximal surface  108 ). 
     A threaded bore  112  may be formed in the proximal surface  108  of the sidewall  106 . As will be explained in more detail hereinafter, the threaded bore  112  may engage a threaded end of a holding rod that is utilized to position and implant the interbody cage  100  in a disc space defined between two adjacent vertebrae. A key slot  114  may also be formed in the proximal surface  108  of the sidewall  106 . The key slot  114  may extend from the superior surface  104  to the inferior surface  105  of the body member  102 . In an embodiment, the key slot  114  may pass through the threaded bore  112 . As will be explained in more detail hereinafter, the key slot  114  may engage key members extending from a guide member. 
     Formed in the superior surface  104  of the body member  102  may be grooves or cutouts  120  and  122 . As will be explained in detail hereinafter, the grooves  120  and  122  may form reliefs in the superior surface  104  to allow passage of fasteners utilized to secure an interbody plate to vertebrae in a spinal column. The grooves  120  and  122  may extend from the proximal surface  108  of the sidewall  106  toward the distal surface  110  of the sidewall  106 . The grooves  120  and  122  may taper upwards, in the superior direction, as they extend toward the distal surface  110  such that they taper out. 
     One of the grooves  120  and  122  may be disposed on either side of the threaded bore  112 . It will be appreciated that the inferior surface  105  of the body member may contain grooves similar in size, shape and location to the grooves  120  and  122  in the superior surface  104 . In an embodiment, the grooves in the inferior surface  105  may differ in size, shape, and location to the grooves  120  and  122  in the superior surface  104 . 
     Although the body member  102  is depicted as a solid member, it will be appreciated that the body member  102  may take a wide variety of configurations according to embodiments of the present disclosure. In an embodiment, the body member  102  may comprise a hollow interior portion for receiving a bone graft. Further, the body member  102  may be formed from a wide range of biocompatible materials as is known to one having ordinary skill. 
     Pursuant to an embodiment of the present disclosure, the present disclosure may provide a plurality of interbody cages of varying height, i.e., the distance between the superior surface  104  and the inferior surface  105 , to accommodate disc spaces of varying sizes. In an embodiment, a surgeon may trial fit multiple interbody cages until the right fit is obtained. 
     Referring now to  FIG. 2 , there is depicted a holding rod  150  pursuant to an embodiment of the present disclosure. The holding rod  150  may extend from a proximal end  152  to a distal end  154 . A knob  156  may be located at the proximal end  152  of the holding rod  150 . The distal end  154  may include a plurality of threads  158 . A shaft  160  may extend between the proximal end  152  and the distal end  154 . The knob  156  may include grip enhancing means  162 , such as serrations. In an embodiment, the threads  158  on the distal end  154  of the holding rod  150  are configured and adapted to engage the threaded bore  112  of the interbody cage  100  (see  FIG. 1 ). It will be appreciated that the holding rod  150  may be utilized to facilitate the installation of the interbody cage  100  into a disc space between two adjacent vertebrae. 
     The present disclosure further contemplates other means of securing the holding rod  150  to the interbody cage  100 . In an embodiment, the holding rod  150  may engage the interbody cage  100  by a snap or press fit. In an embodiment, the holding rod  150  may include an expandable head, activated proximally, that engages a receiving portion in the interbody cage  100  when the head is expanded. In an embodiment, the holding rod  150  may engage the interbody cage  100  using a twist-lock mechanism. 
     Referring now to  FIG. 3 , there is depicted an interbody plate  170  pursuant to an embodiment of the present disclosure. The plate  170  may include a body member  172  according to an embodiment of the present disclosure. The body member  172  may include a proximal end  174  and a distal end  175  (not explicitly visible in  FIG. 3 , but the distal end  175  is understood to be on the opposite side of the interbody plate  170  from the proximal end  174 ). In an embodiment, the body member  172  of the plate  170  is substantially rectangular in shape. 
     An inner surface  176  of the body member  172  may define a guide hole  178 . In an embodiment, the guide hole  178  may be located in the center of the body member  172 . The guide hole  178  may extend from the proximal end  174  to the distal end  175 . In an embodiment, the guide hole  178  may be noncircular. In an embodiment, the guide hole  178  may be oval. 
     The body member  172  may further comprise fastener holes  180 A,  180 B,  180 C and  180 D. Holes  180 A and  180 B may define a first set of holes and holes  180 C and  180 D may define a second set of holes. The first set of holes  180 A,  180 B may allow fasteners (not explicitly shown) to secure the plate  170  to a first vertebra (not explicitly shown) and the second set of holes  180 C,  180 D may allow fasteners (not explicitly shown) to secure the plate  170  to a second vertebra (not explicitly shown). One of the first set of holes  180 A,  180 B may be disposed on either side of the guide hole  178 . One of the second set of holes  180 C,  180 D may be disposed on either side of the guide hole  178 . The first set of holes  180 A,  180 B may be angled. The second set of holes  180 C,  180 D may be angled. 
     The body member  172  may further comprise a pair of guide holes  182 A and  182 B. The guide holes  182 A and  182 B may facilitate the positioning of a drill guide over the holes  180 A- 180 D as will be explained in detail hereinafter. 
     Referring now to  FIG. 4 , there is depicted an elongated guide member  200  pursuant to an embodiment of the present disclosure. The guide member  200  may have a proximal end  202  and a distal end  204 . A body portion  206  of the guide member  200  may extend between the proximal end  202  and the distal end  204 . The body portion  206  may extend along a longitudinal axis  208 . A cannulation  210  may extend from the proximal end  202  to the distal end  204 . 
     In an embodiment, the guide member  200  may include key members  212  and  214  extending from the distal end  204 . The key members  212  and  214  are configured and adapted to engage the key slot  114  of the interbody cage  100  (see  FIG. 1 ) as will be explained in more detail hereinafter. It will be appreciated that the use of the key members  212  and  214 , and the key slot  114 , prevent the elongated guide member  200  from rotating about its longitudinal axis  208  when removably secured to the interbody cage  100 . 
     In an embodiment, the cannulation  210  is configured and adapted to allow the shaft  160  of the holder rod  150  (see  FIG. 2 ) to be inserted into, and pass through, the guide member  200 . In an embodiment, a cross section of the guide member  200  in a plane perpendicular to its longitudinal axis  208  may be noncircular. In an embodiment, the cross section is oval. The guide member  200  may have an outer surface  216 . In an embodiment, the holding rod  150  and the guide member  200  may be formed as a single unit rather than as a two piece assembly as shown. 
     Referring now to  FIGS. 5 and 6 , there is depicted a drill guide  250  pursuant to an embodiment of the present disclosure. The drill guide  250  may comprise a handle  252 . A shaft  254  may extend from the handle  252 . A base member  256  may be attached to the distal end of the shaft  254 . A first guide tube  258  and a second guide tube  260  may extend from the base member  256 . It will be appreciated that the first guide tube  258  and the second guide tube  260  may each include a hollow passageway for allowing the passage of a drill bit and fasteners through the base member  256 . Further, while the drill guide  250  is shown with two guide tubes, it will be appreciated that, pursuant to embodiments of the present disclosure, the drill guide  250  may comprise a single guide tube or any number of guide tubes. 
     As perhaps best seen in  FIG. 6 , an inner surface  262  of the base member  256  may define a guide hole  264 . In an embodiment, the guide hole  264  is noncircular. In an embodiment, the guide hole  264  is oval. As will be explained in further detail hereinafter, the guide hole  264  may receive the guide member  200  to align and position the drill guide  250  over a disc space. Further, extending from the base member  256  may be a first guide post  266  and a second guide post  268 . As will be explained in more detail hereinafter, the first guide post  266  and the second guide post  268  may align the drill guide  250  with respect to the interbody plate  170 . 
     Referring now to  FIG. 7 , there is depicted a surgical drill  300  according to an embodiment of the present disclosure. The drill  300  may be a manually operated drill. In an embodiment, the drill  300  may be a powered surgical drill. 
     The drill  300  may comprise a handle  302 . A shaft  304  may extend from the handle. It will be appreciated that the diameter of the shaft  304  may allow the shaft  304  to snugly fit in the passageways in the hollow tube guides  258  and  260  of the drill guide  250 . Disposed on the end of the shaft  304  may be a drill bit  306 . The drill bit  306  may be utilized to drill pilot holes in vertebrae as is known to one having ordinary skill. 
     Referring now to  FIGS. 8, 9, and 10 , there is depicted an exploded view of a system  350  for spinal fixation. The system  350  may comprise the interbody cage  100 , the guide member  200 , and the holding rod  150 . As perhaps best viewed in  FIG. 9 , the holding rod  150  is installed into the cannulation  210  of the guide member  200 . The proximal end  202  of the guide member  200  may abut against the knob  156  of the holding rod  150 . The length of the holding rod  150  may be sufficient such that the threads  158  on the distal end  154  extend from the distal end  204  of the guide member  200 . 
     As perhaps best observed in  FIG. 10 , the distal end  154  of the holding rod  150  is installed into the threaded bore  112  of the interbody cage  100 . The knob  156  may provide a grip for a surgeon to grasp and position the interbody cage  100 . In addition, the knob  156  may receive hits from an impaction tool, such as a hammer, to impact the interbody cage  100 . The distal end  204  of the guide member  200  may serve as a depth gauge when installing the interbody cage  100  by abutting against two vertebrae defining the disc space. 
     Further, the key members  212  and  214  extending from the distal end  204  of the guide member  200  may engage the key slot  114  of the interbody cage  100 . It will be appreciated by those of ordinary skill that the key slot engagement positively locates the guide member  200  with respect to the interbody cage  100  and prevents the guide member  200  from moving or rotating about the holding rod  150  or its longitudinal axis  208 . 
     Referring now to  FIGS. 10-14 , there is depicted a spinal fusion procedure according to an embodiment of the present disclosure. As previously described, the holding rod  150  may be utilized to removably secure the guide member  200  to the interbody cage  100  as observed in  FIG. 10 . This may be done prior to installing the interbody cage  100  into the disc space. 
     A disc space  400  defined between a first vertebra  402  and a second vertebra  404  may be prepared by removing the natural disc as is known to those having ordinary skill. Next, the interbody cage  100  may be positioned into the disc space  400  by a surgeon using the holding rod  150  having the guide member  200  disposed thereon. The interbody cage  100  may be impacted into the disc space  400 . Once the interbody cage  100  has been installed in the disc space  400 , it may be positioned using the holding rod  150 . The depth of the cage  100  in the disc space may be determined by the distal end  204  of the guide member  200 , which may abut against the first vertebra  402  and the second vertebra  404 . It will be appreciated that the guide member  200  may extend outside of the body of the patient when attached to the interbody cage  100 . 
     As seen in  FIG. 11 , with the interbody cage  100  positioned in the disc space  400 , the interbody plate  170  is aligned and positioned over the disc space  400  using the guide member  200 . In particular, the proximal end  202  of the guide member  200  is installed into the guide hole  178  of the interbody plate  170 . The plate  170  is then slid down the length of guide member  200  into position over the disc space  400 . 
     The guide member  200  may position and align the interbody plate  170  above the interbody cage  100 . In particular, the inner surface  176  of the plate  170  that defines the guide hole  178  may engage the outer surface  216  of the guide member  200 . It will be appreciated that the noncircular nature of the cross section of the guide member  200  prevents the plate  170  from rotating or otherwise becoming misaligned over the disc space  400 . 
     Once the interbody plate  170  is positioned over the disc space  400 , the drill guide  250  may be installed onto the guide member  200  and positioned over the interbody plate  170 . In particular, the guide hole  264  of the drill guide  250  is installed onto the proximal end  202  of guide member  200  and slid into position over the interbody plate  170 . At this point, the first guide post  266  and the second guide post  268  of the base member  256  of the drill guide  250  may engage the pair of guide holes  182 A and  182 B of the interbody plate  170  to ensure that the drill guide  250  is properly positioned with respect to the plate  170  and the cage  100 . 
     In an embodiment, the drill guide  250  and the plate  170  may be preassembled such that they can be installed as one unit over the guide member  200 . Various methods of securing the drill guide  250  and the plate  170  together are envisioned and fall within the scope of the present disclosure. In an embodiment, the guide posts  266  and  268  may have a press or snap fit into the guide holes  182 A and  182 B of the plate  170 . In an embodiment, the guide posts  266  and  268  may threadably engage the guide holes  182 A and  182 B of the plate  170 . In an embodiment, the drill guide  250  and the plate  170  may be magnetically coupled. Thus, the present disclosure contemplates various engagements means to secure the drill guide  250  and the plate  170  together such that they can be inserted together. Once the fasteners are installed to secure the plate  170 , as explained below, the drill guide  250  may be detached from the plate  170  to allow the drill guide  250  to be removed. 
     Once the drill guide  250  is in place and locked with the plate  170 , the drill  300  may be utilized to drill pilot holes in the vertebrae  402  and  404 . In particular, with the guide tubes  258  and  260  of the drill guide  250  aligned over the first set of holes  180 A,  180 B, the drill  300  may be utilized to drill two pilot holes in the vertebra  402 . It will be appreciated that the drill bit  306  passes through the holes  180 A and  180 B in the plate  170 . Further, as the diameter of the shaft  304  of the drill  300  is just slightly smaller than the diameter of the guide tubes  258  and  260  of the drill guide  250 , the bit  306  will be properly aligned. Once the pilot holes have been created, and before the drill guide  250  is removed, fasteners  410  may be installed into the guide tubes  258  and  260  to secure the plate  170  to the first vertebra  402 . 
     As seen in  FIG. 12 , once the fasteners  410  have been installed into the first set of holes  180 A,  180 B in the first vertebra  402 , the drill guide  250  may be removed from the guide member  200 , reoriented by 180 degrees, and then reinstalled onto the guide member  200 . The drill  300  may then be utilized to drill pilot holes in the vertebra  404 . Again fasteners  410  may be utilized to secure the interbody plate  170  to the vertebra  404  through the second set of holes  180 C,  180 D in the plate  170 . With the interbody plate  170  secured, the drill guide  250  and the elongated guide member  200  may be removed as shown in  FIGS. 13 and 14 . In particular, to remove the elongated guide member  200 , the threads  158  on the distal end  154  of the guide member  200  may be unscrewed from the threaded bore  112  of the interbody cage  100 . As shown in  FIG. 15 , multiple interbody plates  170  may be utilized to fuse several levels of vertebrae of a patient. 
     It will be appreciated that although the engagement that removably secures the guide member  200  to the interbody cage  100  has been described herein as a threaded engagement between the holding rod  150  and the threaded bore  112 , that any engagement that removably secures the guide member  200  to the interbody cage  100  falls within the scope of the present disclosure. Further, it will be appreciated that the grooves in the superior surface  104  and the inferior surface  105  of the body member  102  of the interbody cage  100  allow the fasteners utilized to secure the interbody plate  170  to pass within the grooves. 
     It will be appreciated that it is a distinct advantage of the present disclosure to accurately position the interbody plate  170  above a vertebral gap. This accurate positioning of the plate  170  may allow the length of the interbody plate  170  to be kept to a minimum, which may allow the use of multiple plates  170  at multiple adjacent levels in the spine as shown in  FIG. 15 . This feature may have biomechanical advantages and improve fusion rates over single long plates. It also means that where access is limited, such as in minimally invasive procedures, the more easily small plates can be selected and positioned without fear the screws will damage or move a cage installed between the vertebral space. 
     Further, it will be appreciated that using the plate  170  would mean that the bone fasteners may cut into the cage  100  without the grooves in the superior and inferior surfaces of the cage  100  (see  FIG. 1 ). In an embodiment, the grooves are positioned to align with the shortest plates possible for any given size of cage so that even with a very short plate, the fasteners will not cut the cage. 
     In an embodiment, the plate  170  may be utilized as a buttress plate that is only secured to a single vertebra and whose sole function is prevent back out of a cage. It will be appreciated that this may be useful where a second stage adjustment of the relative position of the vertebrae is desired and would be limited by having fasteners installed into both vertebrae. Such a buttress plate may have one or two screws, but again correct alignment and ease of placement would be helpful using the concepts of the present invention. 
     Those having ordinary skill in the relevant art will appreciate the advantages provided by the features of the present disclosure. For example, it is a feature of the present disclosure to provide a spinal plate selection and positioning system. Another feature of the present disclosure is to provide a guide member that removably attaches to an interbody cage, the guide member aligning and positioning an interbody plate and drill guide. It is a further feature of the present disclosure, in accordance with one aspect thereof, to provide an interbody cage with grooves in its superior and inferior surfaces for allowing passage of fasteners utilized to secure an interbody plate. 
     In the foregoing Detailed Description, various features of the present disclosure are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description of the Disclosure by this reference, with each claim standing on its own as a separate embodiment of the present disclosure. 
     It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present disclosure. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present disclosure and the appended claims are intended to cover such modifications and arrangements. Thus, while the present disclosure has been shown in the drawings and described above with particularity and detail, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made without departing from the principles and concepts set forth herein.