Abstract:
According to some embodiments, a method of inserting a lateral implant within an intervertebral space defined between an upper vertebral member and a lower vertebral member includes creating a lateral passage through a subject in order to provide minimally invasive access to the intervertebral space, at least partially clearing out native tissue of the subject within and/or near the intervertebral space, positioning a base plate within the intervertebral space, wherein the base plate comprise an upper base plate and a lower base plate and advancing an implant between the upper base plate and the lower base plate so that the implant is urged into the intervertebral space and the upper vertebral member is distracted relative to the lower vertebral member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/786,160, filed Mar. 14, 2013, the entirety of which is hereby incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    This application relates generally to devices, systems and methods for the treatment of the spine, and more specifically, to spinal implants and related tools, systems and methods. 
         [0004]    2. Description of the Related Art 
         [0005]    Surgical approaches to the intervertebral space are utilized for a variety of indications and purposes, such as, for example, biopsy (e.g., for evaluation of possible infection, other pathology, etc.), discectomy (e.g., for decompression of nerve roots, to prepare for subsequent fusion procedures, etc.), disc height restoration or deformity correction, disc replacement or repair (e.g., annular repair), discogram, gene therapy and/or other procedures or treatments. 
         [0006]    Various approaches are currently used to access the interbody or intervertebral space of a patient&#39;s thoracic, lumbar and sacral spine. These include anterior approaches (ALIF) (e.g., open, mini-open retroperitoneal, etc.), lateral approaches (e.g., costotranversectomy, extreme lateral, etc.), posterolateral approaches (e.g., posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), etc.) and axial approaches (e.g., axial lumbar interbody fusion). Further, many minimally invasive and percutaneous approaches rely on radiographic landmarks with or without direct view to access a targeted interbody space. In addition, many, if not all, of these currently used approaches require violation of the disc annulus to access the disc space. 
         [0007]    Fusion surgery of the thoracic, lumbar and sacral spine is often performed for a variety of indications, including degenerative joint disease, deformity, instability and/or the like. Typically, traditional fusion approaches involve relatively large, open incisions performed under direct vision. Minimally invasive surgical techniques and corresponding surgical implants have become more popular in an attempt to reduce morbidity and generally improve outcomes. Multiple variations of percutaneous systems (e.g., pedicle screw and rod systems, facet screw systems, etc.) have been developed. Such systems can allow for instrumentation placement with fluoroscopic guidance (e.g., using radiographically recognizable body landmarks) and/or other imaging technologies. Current fusion techniques, including those that utilize open and minimally invasive approaches, often require direct visualization. However, such techniques typically involve traversing spaces that are occupied by neural elements. Thus, these neural elements need to be retracted or otherwise moved during the execution of spinal procedures that precede implantation (e.g., annulotomy, discectomy, disc space and/or vertebral endplate preparation, etc.). Retraction of sensitive neural elements can also be required during the delivery of an implant to the spine. 
         [0008]    These approaches typically require contact and retraction of nerve roots and/or sensitive visceral organs, blood vessels and/or other sensitive portions of the anatomy. Contact and retraction of these structures can place them at risk, thereby increasing the likelihood of complications and damage to a patient. Accordingly, a need exists for improved approaches for spinal fusion and/or access to intervertebral spaces. 
       SUMMARY 
       [0009]    According to some embodiments, a method of inserting a lateral implant within an intervertebral space defined between an upper vertebral member and a lower vertebral member includes creating a lateral passage through a subject in order to provide minimally invasive access to the intervertebral space, at least partially clearing out native tissue of the subject within and/or near the intervertebral space, positioning a base plate within the intervertebral space, wherein the base plate comprise an upper base plate and a lower base plate and advancing an implant between the upper base plate and the lower base plate so that the implant is urged into the intervertebral space and the upper vertebral member is distracted relative to the lower vertebral member. 
         [0010]    According to some embodiments, advancing an implant between the upper and lower base plates comprises using a mechanical device (e.g., a threaded-system using a rotable handle to advance a rod or other actuator, manual or mechanically-assisted device, etc.). In some embodiments, the implant comprises at least one groove and at least one of the upper base plate member and the lower base plate member comprises at least one protruding feature, the at least one groove being configured to align and move relative to the at least one protruding feature. In some embodiments, the implant is delivered through the base plate using a rail or other alignment system. In some embodiments, the implant comprises at least one of PEEK, titanium and/or the like. In some embodiments, the base plate comprises titanium, stainless steel or another medically-acceptable metal or alloy. 
         [0011]    According to some embodiments, the method further includes securing at least one screw (e.g., 1, 2, 3, 4, more than 4, etc.) through an opening of the implant after the implant has been properly secured within the intervertebral space. In one embodiment, the screw also passes through at least a portion of the upper or lower base plate member and/or the upper or lower vertebra. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    These and other features, aspects and advantages of the present application are described with reference to drawings of certain embodiments, which are intended to illustrate, but not to limit, the present inventions. It is to be understood that these drawings are for the purpose of illustrating the various concepts disclosed herein and may not be to scale. 
           [0013]      FIG. 1  schematically illustrates one embodiment of a spinal implant system with the implant not positioned within the target intervertebral space; 
           [0014]      FIG. 2  illustrates the system of  FIG. 1  with the implant positioned between the base plate members and implanted within the intervertebral space; 
           [0015]      FIGS. 3A and 3B  illustrate various views of a base plate of an implant system according to one embodiment; 
           [0016]      FIG. 4  illustrates a side view of a spinal implant system according to one embodiment; 
           [0017]      FIGS. 5A-5C  illustrate various views of one embodiment of a base plate for use in a spinal implant system; 
           [0018]      FIGS. 6A and 6B  illustrate various views of one embodiment of an implant configured for use in a spinal implant system; 
           [0019]      FIG. 7A  illustrates one embodiment of a base plate configured for use in a spinal implant system; 
           [0020]      FIG. 7B  illustrates one embodiment of an implant configured to be used together with the base plate of  FIG. 7A ; 
           [0021]      FIGS. 8A-8C  illustrate various time-sequential side views during a spinal implant procedure according to one embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    A variety of examples described below illustrate various configurations that may be employed to achieve desired improvements. The particular embodiments and examples are only illustrative and not intended in any way to restrict the general concepts presented herein and the various aspects and features of such concepts. 
         [0023]    According to some embodiments, the present application discloses various devices, systems and methods for accessing the intervertebral or interbody space of a patient&#39;s spine and/or performing certain procedures related to spinal fusion using minimally invasive surgery (MIS) techniques. As discussed in greater detail herein, the intervertebral or interbody space of the targeted portion of the patient&#39;s spine is accessed and/or treated minimally invasively using, at least in some embodiments, a lateral approach. The terms “intervertebral space” and “interbody space” are used interchangeably herein, and generally refer to the space, gap or region between adjacent vertebral members. By way of example, as illustrated in  FIG. 1 , the intervertebral space  14  between adjacent vertebrae  10 ,  12  can be accessed using one or more lateral openings or passages created laterally through the subject&#39;s anatomy (e.g., using one or more access device, such as, retractors, dilators, etc.). In some embodiments, such openings or passages are created, accessed and/or otherwise use using MIS techniques or procedures. 
         [0024]      FIG. 1  schematically illustrates one embodiment of a spinal fusion or stabilization system  50 . As shown, the system  50  can include upper and lower plates  300  or other members that are positioned along the endplates of the upper and lower vertebral members  10 ,  12 . In some embodiments, the plates  300  generally extend across the entire or substantially the entire width of the vertebrae  10 ,  12 . In some embodiments, the plates  300  are the same length or substantially the same length as the spinal implant  200  that will be delivered between the plates  300  and into the intervertebral space  14 . For example, the plates  300  and/or the implant  200  can be approximately 40 to 60 mm long (e.g., 40, 45, 50, 55, 60 mm, lengths between the foregoing ranges, etc.). In other embodiments, however, the length of the implant is greater than 60 mm or less than 40 mm, as desired or required. 
         [0025]    In some embodiments, once the plates have been properly positioned within the target intervertebral space  14 , the implant  200  can be delivered (e.g., laterally) between the upper and lower plates or other members  300 . The delivery of the implant  200  between the plates  300  can be performed with or without the use of a mechanical delivery tool (e.g., by using a threaded delivery device or other device providing for mechanical advantage, etc.). Regardless of the exact manner in which the implant  200  is advanced into the intervertebral space  14 , the upper and lower plates  300  can provide one or more advantages or benefits. For example, the use of the plates  300  can help distribute forces and moments along a larger surface area. This is schematically and generally illustrated by the force distribution diagram F in  FIG. 2 . Accordingly, the likelihood of potentially damaging localized forces, moments and/or other stresses on a particular portion or area of the adjacent vertebrae  10 ,  12  can be reduced or eliminated. 
         [0026]    Further, in some embodiments, the use of the upper and lower plates  300  can facilitate the delivery of the implant  200  within the target interbody space with greater ease and less resistance. As a result, the endplates and other portions of the adjacent vertebrae  10 ,  12  can be protected against shearing, fractures and/or other damage. This can be especially important when the implant  100  causes distraction (e.g.,. separation or opening) of a collapsed or partially collapsed interbody space  14 , as represented by the arrows  16  in  FIG. 2 . 
         [0027]    As discussed herein, one or both sides of the upper and/or lower plates can include spikes, teeth, other protruding members and/or other engagement features. For example, if such engagement features are positioned along the top of the upper plate or the bottom of the lower plate, the engagement features can be advanced into the adjacent endplate(s) as the implant  200  is moved between the plates  300 . This can help secure the plates to the adjacent vertebrae  10 ,  12 . In some embodiments, engagement features can be positioned along the opposite surfaces of the plates (e.g., along the bottom of the upper plate and/or along the top of the lower plate). Such engagement features can help prevent or reduce the likelihood of relative movement between the implant  200  and the plates  300  following implantation. As discuss in greater detail herein, the plates can include one or more other features, such as, for example, rails or guiding members (e.g., to assist in moving the implant more easily and more predictably between the plates), tabs or other portions configured to receive one or more screws or other fasteners (e.g., to further secure the system  100  to the spine after delivery into the intervertebral space) and/or the like. 
         [0028]      FIGS. 3A and 3B  illustrate different views of one embodiment of plates (e.g., base plates)  300  configured for use in a lateral spinal fusion system. As shown, the base plates  300  can include upper and lower plates  310 ,  314 . The base plates  300  can be shaped, sized and configured to span across an entire width of the subject&#39;s vertebrae  10 ,  12 . In other embodiments, the base plates  300  extend beyond one or more side of the vertebral periphery or do not extend to the lateral edge of the vertebrae (e.g., are short by a certain clearance distance from one or more lateral edges of the vertebrae). As shown in  FIG. 3A , the plate members  310 ,  314  can include one or more protruding members  320  that extend toward each other (e.g., toward the intervertebral space). Such protruding members can be fixed or movable. For example, in some embodiments, the protruding members  320  are deployable (e.g., before, during or after advancement of an implant between the base plates  300 ). 
         [0029]    With continued reference to  FIG. 3A , a system can include a guiding assembly  500  that can be strategically positioned along one of the lateral ends of the targeted intervertebral space. The guiding assembly  500  can include an alignment device  510  that may comprise one or more alignment components  514 ,  516 . Regardless of its exact configuration and design, the alignment device can advantageously permit a surgeon or other practitioner to accurately position the guiding assembly  500  for the subsequent delivery of an implant therethrough and between the base plates  300 . As shown in  FIG. 3A , the alignment components  514 ,  516  and/or one or more other portions or components of the assembly can include a flange or other abutment or securement portion  518 . Such a flange  518  can be fixedly or movable positioned along the adjacent vertebrae  10 ,  12  of the subject to ensure proper alignment into the targeted intervertebral space. 
         [0030]    As illustrated in  FIG. 4 , an implant  200  can be delivered between the base plates  300  and into the intervertebral space using a mechanical advancement device. Therefore, in some embodiments, the guiding assembly  500  can advantageously comprise a mechanical advancement device or feature. For example, in  FIG. 4 , the guiding assembly comprises a threaded delivery portion that is configured to advance an implant  200  between the base plate members  310 ,  314  by turning a rotable handle or other advancement tool. As a user rotates the handle  520 , a rod  522  or other actuator is moved forwardly (e.g., distally) in the direction of the implant  200 . The implant  200  can be directly or indirectly coupled to the actuator  522  via one or more coupling or other detachable connections  526 , as desired or required. As the rod is advanced distally, the implant (e.g., lateral cage) can be guided between the base plate members  310 ,  314  and into the intervertebral space. Consequently, the base plate members  310 ,  314  separate and are urged toward the adjacent endplates of the vertebrae. In some embodiments, as illustrated schematically in  FIG. 4 , the implant can include a taper (e.g., bullet design) along its distal end to facilitate initial entry and subsequent distraction and separation of the base plate  300 . 
         [0031]    With continued reference to  FIG. 4 , the guiding assembly  500  can include one or more structures  510  that ensure that the implant stays within the guiding assembly  500  and aligned with the intervertebral space during advancement between the plates. Such structure  510  can, for example, help reduce any deflection or misdirection of the implant&#39;s leading end during distal delivery to the intervertebral space, especially when relatively high forces are being exerted on the implant (e.g.,. that may otherwise cause the implant to move our of alignment with the base plates). In some embodiments, the implant  200 , the base plates  300  and/or any other portion of the system can include rails or other alignment features that further help maintain a proper alignment of the implant during advancement between a subject&#39;s vertebrae. 
         [0032]      FIGS. 5A-5C  illustrate various views of another system comprising base plates  300  for receiving a spinal implant. As shown, an alignment device  510 ′ can be positioned relative to one or more of the adjacent vertebrae  10 ,  12  more securely. For example, one or more screws S or other fasteners can be used to secure one or more portions of the alignment device to the upper and/or lower vertebral members of the subject. In some embodiments, the alignment devices  510 ′ comprise one or more flanges or plates P through which the screws S or other fasteners can be placed. Once the alignment device  510 ′ has been secured to the subject, the implant can be delivered between the base plate members  310 ,  314 . The alignment device  510 ′, base plate  300  and/or other portions of the system can be left in place after the implant has been secured between the subject&#39;s vertebrae. In other embodiments, however, one or more components of the system (e.g., base plate  300 , screws, etc.) can be left in place after implantation, and in some instances, may help reinforce or otherwise benefit the treated area. 
         [0033]    One embodiment of an implant  200  that can be used with the spinal systems disclosed herein is illustrated in  FIGS. 6A and 6B . As best shown in the top view of  FIG. 6B , the implant  200  can include one or more open regions or chambers  210  for holding a grafting material. In addition, the implant can include one or more grooves  220  or other recesses along its anterior and/or posterior walls. In some embodiments, such grooves  220  or other features can align and mate with corresponding rails, protrusions or features of the base plate  300 . Accordingly, the grooves, rails and/or other features can help safely, accurately and predictably move the implant  200  into the target intervertebral space (e.g., between adjacent base plate members). 
         [0034]    In some embodiments, the implant comprises PEEK, titanium or other acceptable materials. For example, in some embodiments, the implant  200  comprises a metal edge plate  226  through which one or more screws (not shown in  FIGS. 6A and 6B ) can be subsequently delivered to secure the implant  200  to one or more vertebrae. In some arrangements, the plate  226 , which can be positioned along the proximal end of the implant  200 , comprises titanium or other acceptable metal or alloy. 
         [0035]      FIG. 7A  illustrates a side view of one embodiment of a base plate  300  comprising upper and lower plate members  310 ,  314 . As shown, the base plate members  310 ,  314  can include one or more protruding members  320 . Such protruding members  320  can include tabs, bumps, spikes, other sharp, smooth and/or rounded features or members and/or the like. In some embodiments, the protruding members  310 ,  314  can be fixed (e.g., non-movable, non-deployable, etc.) and/or movable (e.g., selectively retractable, deployable, etc.). For example, in some embodiments, the protruding members  320  of the upper and/or lower plate members  310 ,  314  are deployable using a mechanical connection, a temperature change and/or using some other mechanism of action, device or method. 
         [0036]      FIG. 7B  illustrates a top view of one embodiment of an implant  200  that is configured to be used with the base plate  300  of  FIG. 7A . Specifically, as shown, the implant  200  can include one or more grooves, holes, recesses or other openings  240  that are shaped, sized and otherwise configured to receive corresponding protruding members  320  of the base plate  300 . In some embodiments, the protruding members  320 ′ of the base plate  300  include a curved leading edge in order to permit the groove  240  of the implant  200  to only temporarily engage the member  320 ′ as the implant is advanced into the target intervertebral space. Thus, the protruding members can sequentially engage and disengage a groove on the implant (e.g., in a ratcheting manner). In some embodiments, the implant can only be permitted to be advanced in one direction (e.g., distally). Such an embodiment can be helpful when using base plates  300  that have fixed protruding members  320 . In embodiments comprising deployable protruding members, the need for such ratcheting system (e.g., that permits movement in at least one direction) may not be needed, as the protruding members  320  can be selectively deployed only when the implant is properly positioned between the base plate members. 
         [0037]    In some embodiments, the use of protruding members and corresponding grooves or other recesses can help with guiding an implant  200  between adjacent base plate members (e.g. during delivery). Such embodiments can also assist in securely maintaining the implant in its implanted positioned following delivery of the implant in the target intervertebral space. 
         [0038]    As illustrated schematically in  FIGS. 8A-8C , a lateral implant device in accordance with the various embodiments disclosed herein, can be delivered to the target intervertebral space minimally invasively (e.g., through one or more tissue dilations or other openings). As discussed in greater detail herein, once the base plate  300  has been properly positioned between the subject&#39;s vertebrae  10 ,  12 , a guiding assembly  500  can be positioned through a dilator or other access opening and in general alignment with the targeted intervertebral space. The implant can be advanced using a mechanical device (as illustrated in  FIG. 8A ) and/or using some other method or device. Further, the implant and base plate can include one or more features or members (e.g., rails, grooves, etc.) to assist in accurately moving the implant in the desired anatomical location of the subject&#39;s spine. Once the implant has been advanced between the base plate members  310 ,  314  and properly within the intervertebral space, the guiding assembly  500  can be removed. 
         [0039]    With reference to  FIG. 8B , in some embodiments, a screwdriver or other mechanical device  600  can be delivered through a dilator, cannula or other access device C to advance one or more screws S or other fasteners through corresponding openings along the proximal end of the implant  200 . Therefore, the position of the implant  200  relative to the subject&#39;s spine can be safely and firmly maintained, as shown in  FIG. 8C . The screws S can be routed through the implant, the base plate and/or the vertebra, as desired or required. However, in other embodiments, the use of screws S or other fasteners is not needed or required to maintain the implanted implant between the base plate members and the adjacent vertebrae. In some embodiments, a total of four fixation screws are positioned through the proximal end of the implanted implant (e.g., two above and two below). In other embodiments, more or fewer screws or other fasteners can be used, as desired or required. 
         [0040]    In order to remove disk material, cartilage, endplate or other vertebral tissue and/or native tissue of a subject during an implantation procedure, a surgeon or other practitioner can use any of the rasping or other tissue cutting devices and methods disclosed in U.S. patent application Ser. No. 13/422,816, titled TRANSPEDICULAR ACCESS TO INTERVERTEBRAL SPACES AND RELATED SPINAL FUSION SYSTEMS AND METHODS, filed Mar. 16, 2012 and published as U.S. Publ. No. 2012/0265250 on Oct. 18, 2012, and U.S. Provisional Patent Application No. 61/783,839, titled DEVICES AND METHODS FOR TRANSPEDICULAR STABILIZATION OF THE SPINE and filed on Mar. 14, 2013, the entireties of both of which are hereby incorporated by reference herein and made a part of the present application. 
         [0041]    To assist in the description of the disclosed embodiments, words such as upward, upper, bottom, downward, lower, rear, front, vertical, horizontal, upstream, downstream have been used above to describe different embodiments and/or the accompanying figures. It will be appreciated, however, that the different embodiments, whether illustrated or not, can be located and oriented in a variety of desired positions. 
         [0042]    Although the subject matter provided in this application has been disclosed in the context of certain specific embodiments and examples, it will be understood by those skilled in the art that the inventions disclosed in this application extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the subject matter disclosed herein and obvious modifications and equivalents thereof. In addition, while a number of variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions disclosed herein. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combine with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of the subject matter provided in the present application should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.