Abstract:
A spinal stabilization system and method are provided for treating a patient&#39;s spinal column, for maintaining preselected spacing and movement between adjacent vertebrae in a spinal column, and for providing overall stability thereto. The system includes an interlaminar member positioned in the space intermediate a first vertebra and the vertebrae positioned immediately below and adjacent to the first vertebra. The interlaminar member is operatively connected to an adjustable support structure and cooperates therewith to maintain the preselected spacing between adjacent vertebrae and to provide overall stability to the spinal column.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 15/408,157, filed on Jan. 17, 2017, which is a continuation of U.S. patent application Ser. No. 15/332,947, filed Oct. 24, 2016, which is a continuation of U.S. patent application Ser. No. 14/209,138, filed Mar. 13, 2014, which claims the benefit of U.S. Provisional Application No. 61/794,543, filed Mar. 15, 2013; the entire disclosures of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of medical apparatus and methods for using the same. More specifically, the present invention relates to systems and methods for treating spinal conditions, and specifically for systems for stabilizing vertebrae in the spinal column. More specifically, the present invention relates to interlaminar vertebral stabilization devices for placement between adjacent vertebra and including supporting devices for stabilization of the vertebral segments above and below the vertebra being treated. 
       BACKGROUND OF THE INVENTION 
       [0003]    Injury to and/or diseases of the spine frequently result in damage to or abnormalities in the vertebrae, the intervertebral discs, the facet joints and to the connective tissue and ligaments around the spine. Such damage or abnormalities may result in spinal instability causing misalignment of the vertebral column and wear of the intervertebral discs and vertebral bony surfaces, a chronic and progressive deterioration which typically results in severe pain, loss or restriction of motion, and eventually, loss of mobility of the individual suffering from the condition. 
         [0004]    One treatment option for addressing spinal disorders is via surgical intervention and the placement of fusion, stabilization and/or repair devices on or adjacent to the spine or between adjacent vertebrae. Certain surgical procedures are irreversible, for example, fusion techniques using bone grafts or synthetic implants to fuse vertebra, and may also significantly alter vertebral range of motion. Other procedures, for example procedures for installing spinal implants or pedicle screw systems for fixating two or more vertebrae, are intricate, time consuming and highly invasive. Alternative solutions include the insertion of interspinous or intra-laminar spacers in the space between adjacent vertebrae to control relative motion between and to stabilize the two vertebrae. However, the stabilization does not extend above or below the insertion point, leaving the remaining portions of the spinal column subject to unstable motion and the potential damage resulting therefrom. 
         [0005]    Various prior art systems have attempted to address the problems described above. U.S. Pat. No. 5,645,599 issued to Samani on Jul. 8, 1997 (the &#39;599 patent), discloses an interspinal implant device having a generally u-shaped, spring-like configuration for insertion between the spinal processes of adjacent vertebrae. Samani&#39;s device includes opposing pairs of upwardly and downwardly extending brackets adapted to be secured to the spinal process, thereby providing for flexible positioning of the adjacent vertebrae. However, the apparatus of the &#39;599 patent does not attribute to the overall stability of the spinal column; its effect being limited to the two specific vertebrae to which it is attached. It is also difficult to attach multiple devices configured in accordance with Samani&#39;s disclosure at adjacent segments due to interference of the bracket portions. 
         [0006]    Hochschuler et al disclose various intra-laminar stabilization systems in U. S. Patent Application Publication No. US 2009/0204150 published on Aug. 13, 2009 (the &#39;150 publication), and in U. S. Patent Application Publication No. US 2011/0106163 published on May 5, 2011 (the &#39;163 publication). The &#39;150 publication discloses a pair of oppositely disposed hook members that are translationally positioned on a rod and adapted to engage the laminar regions of adjacent vertebra and maintain a preselected spacing there between. However, the apparatus of the &#39;150 publication does not stabilize other vertebrae in the spinal column, its effect being limited to the two adjacent vertebrae which it engages. 
         [0007]    The Hochschuler et al. &#39;163 publication discloses an interlaminar stabilizing system which includes a structure adapted to be disposed between two adjacent vertebrae as described above with respect to the apparatus of the &#39;150 publication. The &#39;163 structure further includes a support structure which is secured to the second vertebra to further restrict the interval spacing between the adjacent vertebrae. However, the system of the &#39;163 disclosure also does not stabilize the vertebrae in the remaining portions of the spinal column for the reasons set forth above. 
         [0008]    Moreover, none of the known prior art systems address the problem of “transition syndrome” or “adjacent segment disease” associated with fusion of adjacent vertebrae. In fusion, if a motion segment is eliminated via fusion, the unfused adjacent segments above and below the fused vertebrae take up and bear the additional forces induced by bending and rotational movement of the spine, which may result in so-called “transition syndrome” over the long term. In addition, none of the prior art systems provide for augmenting previously installed spinal hardware to enhance stability, adjust intervertebral distraction, and so forth. 
         [0009]    Accordingly, a need exists for an improved spinal stabilization system which provides both flexibility and stability to the spinal column and which addresses the combination of problems not solved by the prior art. 
       SUMMARY OF THE INVENTION 
       [0010]    The stated problems and other needs in the art as apparent from the foregoing background may be addressed in accordance with the systems and methods of the present invention as set forth in various embodiments disclosed herein. 
         [0011]    In an embodiment, an improved spinal stabilization system is provided for maintaining preselected spacing and movement between adjacent vertebrae and also for providing overall stability to the spinal column. 
         [0012]    In one embodiment, a spinal stabilization system is provided which includes at least one interlaminar member adapted to be inserted between two adjacent vertebrae and a stabilizing structure for stabilizing the vertebrae at least one layer above and below the two adjacent vertebrae. 
         [0013]    In another embodiment, a spinal stabilization system is provided which includes a blocking member to limit movement of adjacent vertebrae to prevent narrowing of the spinal canal and nerve compression. 
         [0014]    In yet another embodiment, a spinal stabilization system is provided which includes at least one adjustable cross-linking member to enhance stability of the spine. 
         [0015]    In still another embodiment, a method for treating a patient&#39;s spinal column is disclosed employing at least one of the embodiments of the spinal stabilization system of the present invention. 
         [0016]    These and other features of the present invention will be apparent from the accompanying description of the invention, diagrams and supplemental supporting materials provided herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a front plan view of a spinal stabilization system of the present invention; 
           [0018]      FIG. 2  is a side perspective view of a spinal stabilization system of the present invention; 
           [0019]      FIG. 3  is a side plan view of a spinal stabilization system of the present invention; 
           [0020]      FIG. 4  is a bottom perspective view of a spinal stabilization system of the present invention; 
           [0021]      FIG. 5  is a top perspective view of a spinal stabilization system of the present invention; 
           [0022]      FIG. 6  is an enlarged side plan view of a portion of the spinal stabilization system of the present invention shown in  FIG. 3  showing an upper portion of the stabilization system affixed to a spinal column; 
           [0023]      FIG. 7  is a side perspective view of a portion of the spinal stabilization system shown in  FIG. 6 ; 
           [0024]      FIG. 8  is an exploded front perspective view of a portion of the spinal stabilization system shown in  FIGS. 6 and 7 ; 
           [0025]      FIG. 9  is an exploded rear perspective view of a portion of the spinal stabilization system shown in  FIGS. 6, 7 and 8 ; 
           [0026]      FIG. 10  is a front plan view of a spinal stabilization system of the present invention affixed to a spinal column; 
           [0027]      FIG. 11  is a bottom front perspective view of a spinal stabilization system of the present invention affixed to a spinal column; 
           [0028]      FIG. 12  is a top front perspective view of a spinal stabilization system of the present invention affixed to a spinal column; and 
           [0029]      FIG. 13  is a side perspective view of a spinal stabilization system of the present invention affixed to a spinal column. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0030]    It should be noted that the present description is by way of illustration only, and that the concepts and examples presented herein are not limited to use or application with any single system or methodology. Hence, while the details of the system and methods described herein are for the convenience of illustration and explanation with respect to the exemplary embodiments, the principles disclosed may be applied to other types of spinal stabilization systems without departing from the scope of the present invention. 
         [0031]    Referring now to  FIG. 1 , a spinal stabilization system according to an embodiment of the present invention is shown generally at  10  (which for purposes of brevity will be referred to herein as “the system”). The system includes a first interlaminar member  12  adapted to be positioned between adjacent vertebra in a spinal column. As shown in greater detail in  FIGS. 6 and 7 , the interlaminar member  12  is shown positioned between a first vertebra  14  and a second adjacent vertebra  16  in a spinal column  18 . 
         [0032]    The system further includes a second interlaminar member  20  adapted to be positioned between the second vertebra  16  and a third vertebra  22  in the spinal column  18 . Both the first and second interlaminar members are operatively connected to a support structure shown generally at numeral  25  in  FIG. 1 . By way of example, in the embodiment shown, the support structure and the first interlaminar member are integrally formed from a single piece of material such as titanium or stainless steel suitable for use as a medical implant device. However, it is to be understood that other means for connecting the interlaminar device to the support structure such as hinges, pins, threaded fasteners and the like may also be used without departing from the scope of the invention. 
         [0033]    The support structure  25  comprises a pair of support members or guide rods  28  secured to the first interlaminar support member  12  and extending in a direction upwardly therefrom substantially parallel to one another. The second interlaminar member  20  includes a body portion  21  of a preselected thickness t, which is most clearly illustrated in  FIG. 9 . Thickness t is selected based upon the spacing between the second and third vertebrae and is intended to be smaller in size than the spacing to allow for flexion of the spinal column  18 . 
         [0034]    The body portion  21  further includes a pair of oppositely positioned ears  30  extending laterally outwardly from the body portion in opposing directions, each of the ears containing an aperture  32  structured and arranged to slideably receive one of the support members or guide rods  28 . As will be discussed in greater detail below, the second interlaminar member is movably supported by upwardly extending support members or guide rods, and the position of the second interlaminar member  20  relative to the first interlaminar member  12  may be adjusted depending upon the dimensions of the specific spinal column on which the system is installed and the range of motion desired. Once the position of the second interlaminar member  20  has been selected, it is locked in place by a pair of set screws or other suitable fastening means  34  extending through each of the ears  30  and adapted to releaseably engage the respective guide rod extending therethrough. 
         [0035]    Referring now to  FIGS. 2, 3, 7 and 8 , the first interlaminar member is 12 depicted in greater detail. The first interlaminar member comprises a U-shaped body  40  defined by an elastic midsection  42 , two spaced apart end portions  44 , and a pair of juxtaposed legs  46 , each leg extending substantially parallel to one another from one of the respective ends in a direction generally outwardly away from the spinal column  18  ( FIG. 7 ) and spaced apart a preselected distance d. Distance d is determined by the size of the first interlaminar member, which, in turn, is selected based upon the spacing between the first and second vertebrae. The first interlaminar member is intended to fuse the first and second vertebrae. Accordingly, it is sized to be a tight fit, and the elastic properties of the U-shaped body  40  act as a spring or shock absorber in the interface between the two vertebrae. Further, the uppermost one of the legs  46  is longer than the lower one of the legs, thereby forming a handle  48  which may be used to insert and position the system during surgery. 
         [0036]    Referring again to  FIG. 1 , the support structure  25  further includes a T-shaped frame member  50  operatively connected to the first and second interlaminar members  12  and  20  and extends generally downwardly therefrom in a direction substantially parallel to the spinal column  18 . The T-shaped frame member includes an elongate body  52  having first and second end portions  54 ,  56 , the first end portion being operatively connected to the first interlaminar member  12 , and an elongate cross member  58 . The cross member has first and second end portions  60 ,  62  and a midpoint  64  and is structured and arranged to be connected to the second end portion  56  of the body  52  at approximately the midpoint  64 . Each of the ends  60 ,  62  of the cross member  58  are adapted to receive and adjustably secure first and second support members  66  and  68  respectively. In the embodiment shown, each of the end portions  60 ,  62  have an aperture  70 ,  72  formed therein respectively for receiving one of the support members  66 ,  68 , each of which may be held in a preselected position by a set screw  74 . 
         [0037]    In the embodiment shown, by way of example only and not of limitation, the support members are in the form of guide rods  66 ,  68 , each guide rod having an upper end  76  and a lower end  78 . Each of the upper and lower ends of the support members  66 ,  68  has a securing device  80  slideably positioned thereon and adapted to be secured thereto by means of set screws  82 . By way of example, each of the securing devices is shown in the form of a pedicle screw  84 , each pedicle screw being structured and arranged to be secured to one of the vertebra of the spinal column  18 . 
         [0038]    The installation and operation of the spinal support system  10  of the present invention are illustrated in greater detail in  FIGS. 6, 7, and 10-13 . The system advantageously may be installed where other spinal fusion devices or similar medical apparatus are already in place to add stability to the spinal column above and below the installation point, to control flexion and/or rotational movement of the spine or selected vertebrae with respect to one another, and to prevent impingement of adjacent vertebrae, spinal processes, pedicle screws and medical hardware on one another. By way of example, as best shown in  FIGS. 6 and 7 , a surgeon may insert the system  25  into the space between adjacent vertebrae  14  and  16  by gripping handle  48  and making the insertion. The tight fitting U-shaped body  40  not only serves to control any motion between the adjacent vertebrae or even eliminate it entirely, thereby effectively fusing the vertebrae, but also serves as a dampening cushion or spring device by virtue of the spring-like elasticity of the body  40  translated to the vertebrae via legs  46 . Thereafter, the second interlaminar member  20  may be selectively positioned intermediate vertebra  16  and vertebra  22  to permit flexion on a forward direction but to limit extension in the rearward direction and to limit compression of the spinal segment, thereby imparting enhanced stability to the spinal column above the fused vertebrae. 
         [0039]    In a similar manner, support structure  25 , via the T-shaped frame member  50  and support members or guide rods  66  and  68 , provides support to the spinal processes located below the fused vertebrae  14  and  16 . As shown in  FIGS. 10-13 , the pedicle screws  80  may be positioned in first vertebra  14  and in either vertebra  15  immediately adjacent to vertebra  14 , or at a lower level as shown by vertebra  17 , thus extending the stabilizing effect of the novel support system of the present invention to multiple levels in the spinal column  18 . More than one level may be addressed simply by lengthening the rods  66  and  68  and slideably positioning multiple pedicle screws  80  thereon for selective positioning along the spinal column. 
         [0040]    In one aspect, the cross member midpoint  64  may be configured, structured and arranged to be adjustably (e.g., pivotably or translatably) connected or secured to the second end portion  56  of the body  52  at approximately the midpoint  64  in order to allow a surgeon during the course of the surgical procedure to adjust and align components of the implant in relation to the patient&#39;s bony anatomy and in relation to support members  66  and  68 . 
         [0041]    In another aspect, elongate body  52  may be comprised of multiple pieces. For example, one or more linear racks may be configured in operable relation with gear mechanisms, thereby forming a ratchet device (not shown), in order to extend the distance between first and second end portions  54  and  56  thereby permitting a surgeon during the course of the surgical procedure to adjust and align components of the implant in relation to the patient&#39;s bony anatomy and subsequently securing them in place. For example, a ratchet mechanism configuration may permit the surgeon to progressively extend elements of the implant to better appose a lamina. 
         [0042]    In yet another aspect, each of the ends  60 ,  62  of the cross member  58  may be configured to permit a degree of adjustability (e.g., pivotably or translatably) to receive and adjustably secure first and second support members  66  and  68  respectively. For example any cross-link variable adjustment mechanism or fastener known in the art may be employed to accomplish the desired fixation between the ends  60 ,  62  of the cross member  58  and first and second support members  66  and  68 . 
         [0043]    According to particular embodiments, interlaminar member  20  may be configured to permit connection to guide rods  28  via an approach that is substantially perpendicular to the longitudinal axis of guide rods  28 . In other words, after the other components of the system have been implanted via a posterior approach to the posterior aspect of the spine, the interlaminar member  20  may follow a generally similar approach trajectory and then be secured to the guide rods  28  with, e.g., set screws in a similar manner to the engagement between the ends  60 ,  62  of the cross member  58  and first and second support members  66  and  68 . Furthermore, in another aspect, an interlaminar member  20  may be used alone (and may alternatively be configured to be similar to the U-shaped body  40 ) and may be directly engaged with a first and second support members  66  and  68  and positioned between the lamina and spinous processes of the spine. 
         [0044]    In particular aspects, the different elements of the system may be configured with tool engagement features in order to permit a surgeon to grasp the implant with a tool assembly or insertion tool to ease implantation of the various components. For example, the insertion tool may be configured as a pair of pliers or hemostats. As another example, a threaded portion of a tool assembly may reversibly secure to a complementary threaded portion of the implant in order to ease implantation. E.g., a tool assembly may be comprised of a cannulated shaft with a retainer shaft housed substantially within, the retainer shaft further configured with a threaded portion at its distal end which may extend out of a distal end of the retainer shaft and a handle located and attached to a proximal end of the retainer shaft; the distal end of the retainer shaft may have a feature that permits rotation of the retainer shaft via another tool, such as the mechanical arrangement that exists between a wrench and nut, in order to secure the tool assembly to the implant. After implantation of the implant the tool assembly may be decoupled and removed. 
         [0045]    Changes may be made in the above methods and systems without departing from the scope hereof. It should thus be noted that the matter contained in the above description and/or shown in the accompanying figures should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present systems and methods, which, as a matter of language, might be said to fall there between.