Abstract:
A system and method for stabilizing a spine of an animal subject involving a transverse rod installation instrument assembly for inserting a transverse rod on the spine of a subject percutaneously comprising: a first rod clamp extender mounted on a ipsilateral rod clamp and a second rod clamp extender mounted on a contralateral rod clamp wherein the ipsilateral rod clamp and the contralateral rod clamp are secured to a vertebra at the ipsilateral and contralateral pedicle; and a pivoting installation instrument pivotably mounted to the first rod clamp extender and the second rod clamp extender to pass a transverse rod percutaneously through a head portion of the ipsilateral side rod clamp and to the head portion of the contralateral rod clamp after passing through a spinous process of the vertebra through pivot axis “A” such that the transverse rod is secured at the head portion of the ipsilateral rod clamp and the head portion of the contralateral rod clamp.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application PCT/US14/63152, filed Oct. 30, 2014, entitled “Percutaneous Transverse Connector System”, which claims priority to and the benefit of the filing of U.S. Provisional Patent Application No. 61/898,332, entitled “Percutaneous Transverse Connector System”, filed on Oct. 31, 2013, and the specification and claims thereof are incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0003]    Not Applicable. 
       COPYRIGHTED MATERIAL 
       [0004]    Not Applicable. 
       BACKGROUND 
       [0005]    The system and method of this invention relates to an implantable spinal fixation system for the surgical treatment of spinal disorders and apparatus for implantation. 
         [0006]    Spinal column disorders such as scoliosis, kyphosis, lordosis, spondylolisthesis, ruptured, broken, fractured or slipped discs are treated with spinal fixation. Spinal fixation uses surgical implants or constructs which mechanically immobilize the treated area of the spine with the goal of causing the fusion of the treated vertebrae. One type of spinal fixation utilizes a pair of longitudinal rods that run parallel or longitudinally along the spine and are affixed to pedicles of the appropriate vertebrae or to the sacrum and act as anchor points for the longitudinal rods. Bone screws are generally placed two per vertebrae with one at each pedicle on either side of the spinous process of the vertebrae. Clamp assemblies join the spine rods to the screws. When a pair of transverse rod/connectors are fastended in parallel on either side of the spinous process, the assembly can be significantly strengthened. However, the instrumentation with transverse rods described requires open surgery and a large incision. In doing so, the skin and tissue surrounding the surgical site must be cut, removed and or repositioned in order for the surgeon to access the location where the stabilization device is to be installed. This type of invasive surgery leads to risk of long recovery time, disruption of muscle, trauma damage and scarring to the tissue. 
         [0007]    In recent years minimally invasive spinal (MIS) procedures have become more common. The advantages of MIS procedures compared with open surgery are less pain, faster recovery, less intra-operative blood loss, and generally greater patient satisfaction. With the advent of innovative devices and techniques, physicians now routinely perform MIS procedures that traditionally would require open surgery. One of the shortcomings of MIS procedure/surgery is the inability to place a transverse connector through a percutaneous route. Transverse connectors are used during spinal instrumentation procedures to add rigidity to the overall construct offered by longitudinal rods alone. Transverse rods add stability during axial rotation (twisting) and lateral bending (side to side bending) of the spine. During open procedures the placement of transverse connectors are straight forward but require muscle dissection as well as other downsides mentioned herein. 
         [0008]    Minimally invasive surgery wherein a long incision through a muscle group such as those along the spine to expose multiple levels of vertebrae is not required. Minimally invasive surgery may be achieved with percutaneous minimally invasive spinal procedures where minimal if any muscle dissection is required. Currently minimally invasive surgery is not available to insert transverse rods into the spine, for example, to add rigidity to an instrumentation construct consisting of pedicle screws and longitudinal rods involving multiple levels of vertebrae. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0009]    One embodiment of the present invention provides a transverse rod installation instrument assembly for inserting a transverse rod on the spine of a subject percutaneously. A first rod clamp extender is mounted on an ipsilateral rod clamp and a second rod clamp extender is mounted on a contralateral rod clamp wherein the ipsilateral rod clamp and the contralateral rod clamp are secured to a vertebra at the ipsilateral and contralateral pedicle. A pivoting installation instrument is pivotably mounted to the first rod clamp extender and the second rod clamp extender to pass a transverse rod percutaneously through a head portion of the ipsilateral side rod clamp and to the head portion of the contralateral rod clamp after passing through a spinous process of the vertebra through pivot axis “A” path such that the transverse rod is secured at the head portion of the ipsilateral rod clamp and the head portion of the contralateral rod clamp. Further, the first rod clamp extender has a cylinder with a pair of opposing arms that extends superior to the cylinder wherein at the bottom of the cylinder is a docking ring for engaging with the bolts on a pair of opposing wings of the ipsilateral rod clamp assembly when the cylinder of the first rod clamp extender is positioned over the pair of opposing wings. The pair of opposing arms on the first rod clamp extender includes a hole in each arm of the pair wherein the hole in each arm of the pair of opposing arms aligns. The second rod clamp extender has a cylinder with a pair of opposing arms that extends superior to the cylinder wherein at the bottom of the cylinder is a docking ring for engaging with the bolts on a pair of opposing wings of the contralateral rod clamp assembly when the cylinder of the second rod clamp extender is positioned over the pair of opposing wings. The docking ring has an internal grove for securing the bolt on the side of the wing of the rod clamp assembly when the rod clamp assembly is in use to stabilize the extender onto the rod clamp assembly. The pair of opposing arms on the second rod clamp extender includes a hole in each arm of the pair wherein the hole in each arm of the pair aligns. The first rod clamp extender and the second rod clamp extender are secured together with a bolt that fits through each hole in each arm of the pair of opposing arms of the first rod clamp extender and each hole in each arm of the pair of opposing arms of the second rod clamp extender such that the bolt passes first through an arm of a first rod clamp extender and then through an arm of the second rod clamp extender before passing through the opposing arm of the first rod clamp extender and then the opposing arm of the second rod clamp extender. The pivoting installation instrument pivotably mounted to the first rod clamp extender and the second rod clamp extender is secured to the first rod clamp extender and the second rod clamp extender via the bolt. 
         [0010]    Another embodiment of the present invention provides for an orthopedic clamp system for use with a rod for immobilizing bone comprising a rod clamp assembly having a clamp with an upper surface and a lower surface and a rod receiving section positioned superior to the clamp the rod receiving section having a pair of opposing wings that extend from the rod receiving section. The clamp includes a tightening screw through its upper surface for securing the clamp to a longitudinal rod immobilized to the bone and a polyaxial head that is positioned between the rod receiving section and the clamp. The polyaxial head allows for freedom of movement when positioning a transverse rod passer in the rod receiving section. The rod receiving section is threaded to mate with a set screw to tighten a transverse rod positioned in the rod receiving section. The pair of opposing wings include a bolt on an outer surface of the pair of opposing wings used to secure a docking ring of a rod clamp extender when the rod clamp extender is positioned over the pair of opposing wings. The pair of opposing wings create an open space along the length “L” of the rod clamp assembly which space permits a transverse rod receiving section to be observed from above. The wings above the rod receiving section are releaseably attached to the rod receiving section. 
         [0011]    Another embodiment of the present invention provides for a method for inserting a transverse spinal rod into a patient comprising attaching a first rod clamp assembly onto a first longitudinal rod that is secured to a first vertebrae having a first side of a spinous process of the patient wherein the first rod clamp assembly is introduced to the longitudinal rod through a first minimally invasive incision on the back of the patient at the level of the first vertebrae. A second rod clamp is attached to the assembly onto a second longitudinal rod that is secured to the first vertebrae on a second side of the spinous process of the patient wherein the second rod clamp assembly is introduced to the longitudinal rod through a second minimally invasive incision on the back of the patient at the level of the first vertebrae. A first rod clamp extender is placed onto a pair of opposing wings of the first rod clamp assembly. A clamp of the first rod clamp assembly is secured to the first longitudinal rod with a screw on the upper surface of the clamp of the first rod clamp assembly. A second rod clamp extender is secured onto a pair of opposing wing of the second rod clamp assembly. A clamp of the second rod clamp assembly is secured to the second longitudinal rod with a screw on the upper surface of the clamp of the second rod clamp assembly. An extracorporeal portion of the first rod clamp extender is secured to an extracorporeal portion of the second rod clamp extender via a transverse rod passer pivotably mounted to the first rod clamp extender and the second rod clamp extender about a pivot axis “A” whose pivot axis passes through the head of the first rod clamp assembly, the spinous process, and the head of the second rod clamp assembly. A transverse rod opening is created in the spinous process by piercing the spinous process with an awl that is directed to the spinous process via the transverse rod passer as the transverse rod passer is moved through pivot axis “A” path percutaneously. The transverse rod connector is inserted into the head of the second rod clamp assembly after passing through the spinous process and through the head of the first rod clamp assembly via the transverse rod connector guiding the transverse rod through pivot axis “A” path. The transverse rod is secured to the first rod clamp assembly. 
         [0012]    Further still, the transverse rod is connected to a handle with a flexible section that is removable from the transverse rod for allowing the transverse rod to be positioned in a guide tube of the transverse rod passer. An awl for creating an opening in the spinous process includes a handle having a flexible shaft and a sharp tip portion that is inserted through the guide tube of the transverse rod passer. The first rod clamp assembly and the second rod clamp assembly is disconnected from the transverse rod passer. The screw on the upper surface of the clamp of the first rod clamp assembly is tightened with a screw driver inserted percutaneously. The pair of opposing wings of the first rod clamp assembly is detached from the head portion leaving the head portion secured to the transverse rod. 
         [0013]    Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0014]    The accompanying drawings in the attachment, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings: 
           [0015]      FIG. 1A-C  is an illustration of a rod clamp and rod clamp assembly according to one embodiment of the present invention from different view; 
           [0016]      FIG. 2  is a stabilizing tower to slide over wings of a rod clamp according to one embodiment of the present invention; 
           [0017]      FIG. 3A-G  illustrates a transverse rod passer system according to one embodiment of the present invention; 
           [0018]      FIG. 4  illustrates a transverse rod installment instrument assembly according to one embodiment of the present invention; 
           [0019]      FIG. 5  illustrates a transverse rod passer assembly in association with a spinous process of a vertebra according to one embodiment of the present invention; 
           [0020]      FIG. 6  illustrates a transverse rod through the spinous process of a vertebra in association with the transverse rod passer assembly according to one embodiment of the present invention; and 
           [0021]      FIG. 7  illustrates a transverse rod associated with rod clamps and bony structure of a vertebra according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    As used herein “a” or “an” means one or more. 
         [0023]    One aspect of one embedment of a present invention provides for a system and method for placement of a transverse connector on the spine of an animal subject (e.g. human) wherein minimal if any muscle dissection is required. 
         [0024]    A set of innovative instruments and method of using the same that allow precise placement of a transverse rod across the vertebrae to a transverse rod connector through a percutaneous route. 
         [0025]    According to one embodiment of the present invention a method for spinal fusion of adjacent vertebral bodies is provided wherein an installation instrument for guiding a transverse rod to connect with a rod clamp through a minimally invasive incision is discussed. The method further provides that the transverse rod is passed through the head of an ipsilateral rod clamp and inserted through spinous process before connecting with the head of a contralateral rod clamp. 
         [0026]    An aspect of the present invention provides a transverse rod installation instrument for transcutaneous placement of a transverse rod wherein the installation instrument is mounted to rod clamp extensions whose position is secured in an animal subject. 
         [0027]    One aspect of one embodiment of the present invention is a minimally invasive method to stabilize bony structures. 
         [0028]    One aspect provides for a method to connect two (2) or more rod clamps with a connecting element. 
         [0029]    A method to attach a transverse rod inserter on an installation instrument to the extensions and guiding the transverse rod into a desired position relative to the rod clamps. 
         [0030]    A fixed geometric relationship to guide the transverse rod into a position proximate to the rod clamps. 
         [0031]    According to one embodiment of the present invention an installation instrument is mounted to the rod clamp extension element in spatial relation to the anchors about a pivot point. The instrument is rotated about the pivot point to guide the transverse rod to the desired location. 
         [0032]    According to another embodiment of the present invention an installation instrument assembly is provided having an ispilateral rod clamp extension designed to slide onto the wings of an ipsilateral rod clamp and a contralateral rod clamp extension designed to slide onto the wings of a contralateral rod clamp. The rod clamp extensions each have an arm with a hole at the end of the arm through which the two rod clamp extensions are secured together. The installation instrument mounts to the ipsilateral and contralateral rod clamp extension arms when the rod clamp extensions are mounted to rod clamps positioned on either side of the spinous process of a vertebra. In this position, the two arms will overlap slightly when the rod clamp extensions are properly positioned on the rod clamps to allow the holes at the end of each arm to overlap. The installation assembly is held together with a fastener that passes through all four holes of the arms including the holes of the arms and the holes at the attachment ends of the installation instrument which sandwich the two holes of the arms to connect the installation instrument assembly together. The rod clamps to which the rod clamp extension are mounted are positioned on either side of spinous process and the rod clamps are secured to a pedicle of a vertebra structure with pedicle screws. The installation instrument is pivotable about a pivot axis that is formed by a line that runs through the holes of the side arms and holes of the attachment ends when assembled. The installation instrument is moveable with respect to the rod clamps to position a transverse brace through the spinous process of the vertebra and secure the ends of the transverse rod to the head of the ipsilateral and contralateral rod clamps. 
         [0033]    Referring now to  FIGS. 1A  rod clamp assembly  100  having a pair of opposing wings  104  that extend from clamp  101  includes a tightening screw  105  which locks the clamp  101  to the longitudinal rod  102  (not shown). There is a polyaxial head  109  which allows for freedom of movement when positioning the rod passer. Referring now to  FIG. 1B , a tightening screw  105  sits in the superior portion of the clamp  101  and acts to close down on the longitudinal rod on the medial side of the rod but can secure the rod on the lateral side of the rod as well. As shown by the arrows at the wings, the poilyaxial head also allows for rotation. Bolts  111  are positioned on the side of the wings and are used to secure the extenders (not shown) when the extenders are positioned over the wings. Referring now to  FIG. 1C , the clamp  101  is secured to a longitudinal rod  102 . The longitudinal rod  102  is secured to a bony structure such as a vertebra with a pedicle screw inserted into a pedicle of the vertebra. The longitudinal rod  102  is positioned in the clamp  101 . Once pedicle screws and longitudinal rods are placed, a site is identified on the rod clamp  100  where the transverse connector will be connected, for example at head  107  of rod clamp assembly  100 . The head  107  has threads and below the threads a transverse rod trough which is located superior to the clamp  101 .  FIG. 1C  is a side view of the rod clamp and wings. The wings  104  create a space  103  along the length “L” of the rod clamp as illustrated. A portion of the wind of the rod clamp assembly is located extracorporeal. An empty portion at the head  107  of rod clamp assembly is identified where the transverse connector will be attached and secured with set screws. The set screws are introduced through the distal opning of the rod clamp assembly. 
         [0034]    Facial openings are made is the skin and muscle and a standard nasal speculum is used to visualize the rod clamp  100  and longitudinal rod  102 . 
         [0035]    Referring now to  FIG. 2 , a stabilizing tower  201  is placed on the wings  104  of the rod clamp assembly  100  and passes down the rod clamp wings  104 . Opening  202  in stabilizing tower  201  is used to insert screw driver for tightening screw  105  of  FIG. 1B . Once the clamp is seated on the longitudinal rod for example, the rod clamp sits as deep as possible against the longitudinal rod. The tightening screw  105  on the rod clamp  101  is tightened to prevent the rod clamp  101  from becoming disengaged from the longitudinal rod  102 . In the case of a spinal fusion there would be two rod clamps with a first rod clamp secured on a left pedicle of vertebra V and a second rod clamp secured on a right pedicle of vertebra V as is shown in  FIG. 5 . 
         [0036]    The stabilizing tower is removed from the rod clamp wings. Referring now to  FIG. 3A-3G , rod clamp extender/extension  303 A having arm  301 A with a hole  302 A is placed over the wings of a rod clamp assembly  100 . Rod clamp extender/extension cyclinder  303 B having arm  301 B with a hole  302 B is placed over the wings of a second rod clamp attached to a different part of the bony structure. Hole  302 A is aligned with hole  302 B having a bolt that fits in hole  302 A while hole  302 A 1  is aligned with hole  302 B 1  having a bolt that fits in hole  302 A 1  and also with attachment end  315  of  FIG. 3D  and attachment end  313  of  FIG. 3D  of installation instrument  307  of  FIG. 3D  such that rod clamp extension  303 A, rod clamp extension cyclinder  303 B and installment instrument  307  can be secured together by nut  305  at the end of rod  304  of  FIG. 3C  as is illustrated for the assembly in  FIG. 4 . An awl  329  of  FIG. 3E  having a handle  317 , a flexible shaft (for example a spring)  319  and a tip portion  321  is inserted through the guide tube  309  of instrument  307  as illustrated in  FIG. 3D . The flexible shaft permits the shaft  319  of the awl to flex during insertion in guide tube  309 .  FIG. 3B  identifies the interior of the extender of either  303 A or  303 B. There is a docking ring  306  for locking the extender onto the bolt  111  of wing  104  when the assembly is in use and the rod is passed through the spinous process. An internal grove  310  secures the bolt  111  to stabilize the extender onto the wing of the rod clamp.  FIG. 3F  illustrate a transverse rod connected to a handle with a flexible section. The handle and flexible section are removeable from the transverse rod. The portion of  324  that is flexible for allowing the transverse rod to be positioned in guide tube  309 .  FIG. 3G  illustrates a cross sectional view  316  of the extenders in position over the rod clamp wings. The groove  317  at the bottom of the extenders slide over the bolts  111 . Once the extenders are securely seated, the docking ring  306  locks the extender onto the rod clamp wings. 
         [0037]    Referring now to  FIG. 4 , the installation instrument assembly  307  attached to the arms of rod clamp extender is illustrated. The pivot Axis “P” about which the installation instrument pivots is illustrated. The arms  301 A and  301 B join and may be connected to attachment end  315  and attachment end  313  with connector of  FIG. 3C . Alternative installment instrument  307  can be used with end  305  securing section  304  in place. 
         [0038]    A skin and facial incision is made for when the awl  329  enters the skin on the Ipsilateral side of the body and the guide tube  309  is advanced until the spinous process is encountered. Referring now to  FIG. 5 , with firm pressure the awl  329  positioned in guide tube  309  is advanced through the spinous process along arc A on radius R. Visual confirmation through the contralateral rod clamp will confirm that the awl has passed through the spinous process. The guide tube  309  sits in the tranverse rod trough of  107  which is superior to  101  but leaves adequate space at the bottom for the awl  329  to pass through. 
         [0039]    Referring now to  FIG. 6 , the guide tube  309  follows the same trajectory as the awl is then swung out, the awl is removed and a permanent transverse rod  324  of the appropriate length (confirmed on fluoroscopy) is inserted in the guide tube  309  of the traverse rod passer. The guide tube  309  of the transverse rod passer is again advanced through arc A over radius R until the transverse rod  323  is appropriately seated in the head portion  107  of the rod clamps  101 . The installation instrument is removed. The rod clamp extension is removed and wings  104  are broken off above section  107  leaving behind the transverse rod anchor  703  located superior to the clamp  101  with the transverse rod and the longitudinal rod in position secured to the bony structures of the pedicle and the spinous process. 
         [0040]    Referring now to  FIG. 7 , transverse rod anchor  703  secured to the transverse rod  323  via set screws (not shown) with clamp  101  secured to longitudinal rod  102  with longitudinal rod  102  secured to the vertebrae by pedicle screws (not shown) is illustrated. 
         [0041]    Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference