Abstract:
A guide wire comprises a longitudinal body having a proximal end portion and an opposing distal end portion. The proximal and distal end portions have rigid shafts with a flexible portion disposed therebetween. The flexible portion is fixedly attached to the proximal end portion and distal end portion. An outer surface of the flexible portion has a diameter equal to an outer surface of the proximal end portion and an outer surface of the distal end portion. The distal end portion further comprises at least one marker disposed therein configured to locate a distal tip of the guide wire during imaging.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The subject invention claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/247,011 filed Oct. 27, 2015 and U.S. Provisional Patent Application Ser. No. 62/247,020 filed Oct. 27, 2015, the disclosures of which are herein incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The subject invention is directed to a medical device, and more particularly, to a guidewire for spinal fixation. 
         [0004]    2. Description of Related Art 
         [0005]    The human spinal column consists of a series of thirty-three stacked vertebrae. Through injury or disease, one or more components of a vertebra become damaged thereby necessitating spinal procedures to remove or modify the damaged component. One way to stabilize the spinal column after such procedures is through spinal fixation. 
         [0006]    A spinal fixation procedure can involve rigidly or dynamically fixing adjacent stacked vertebrae vertically through bone grafting and/or rigid mechanical fixation assemblies. A spinal fixation device used in such a procedure may be a rigid or semi-rigid mechanical support system which is surgically implanted into the vertebral column in order to obtain stabilization of spinal fractures, correction of spinal deformities, or treatment of degenerative spinal disease. 
         [0007]    The percutaneous technique used to gain access to the intervetebral disc is well known to those of skill in the art. Generally, this technique can be used to place a guide-wire and cannula under C-arm fluoroscopic guidance. Typically, the surgeon would advance a sufficient length of the guide wire into the surgical site to make contact with the bony structure or soft tissue where the surgeon wishes to perform a surgical procedure. When performing spine surgery, the surgeon generally advances a variety of surgical tools over the guide wire, such as a drill and a tap for creating a threaded hole, and then the surgeon typically advances a cannulated bone screw over the guide wire for attachment to the bony structure or tissue. However, when using a relatively stiff guide wire the guide wire can block a surgeon&#39;s field of view because the wire is not easily manipulated. 
         [0008]    Further, the guidewire distal tip follows a tortuous or winding path as it is inserted into the subject. The distal tip is flexible to avoid damaging interior walls and/or tissue that the guidewire tip contacts along the winding path. One problem with currently available guidewires concerns the visibility of the guidewire. If the guidewire is fully opaque on a viewing screen, it can hinder viewing. Guidewires that have only an opaque tip do not adequately depict the path on the viewing monitor. 
         [0009]    Therefore, there arises a need for a guidewire that is made from a single piece having a flexible portion with a marker to allow the guidewire to follow the tortuous path and having a sufficient column strength to allow manipulation of the guidewire from an external access site and including viewing capabilities. 
       SUMMARY OF THE INVENTION 
       [0010]    The subject invention is directed to a new and useful guide wire that includes a longitudinal body having a proximal end portion and an opposing distal end portion. The proximal and distal end portions have rigid shafts. A flexible portion is disposed between the proximal and distal end portions. 
         [0011]    The flexible portion is fixedly attached to the proximal end portion and distal end portion. An outer surface of the flexible portion has a diameter equal to an outer surface of the proximal end portion and an outer surface of the distal end portion. The flexible portion is a coil tube that includes stainless steel. 
         [0012]    The proximal portion has a longitudinal dimension shorter than a longitudinal dimension of the distal portion and the flexible portion individually. The flexible portion has a longitudinal dimension shorter than a longitudinal dimension of the distal portion. The flexible portion is approximately five inches. The distal portion is approximately thirteen inches and the proximal portion is approximately one inch. The distal end portion has a distal tip configured for guiding a pedicle screw insertion. 
         [0013]    The subject invention is also directed to a guide wire comprising a longitudinal body having a proximal end portion and an opposing distal end portion. The distal end portion having at least one marker disposed therein configured to locate a distal tip of the guide wire during imaging. The at least one marker is a high density biocompatible material placed within the distal end portion of the guide wire. The at least one marker is positioned such that a central portion of the marker is co-linear with a distal tip of the guide wire. 
         [0014]    Preferably, the at least one marker is machined into a core of the longitudinal body. In one embodiment, the at least one marker is a straight wire. In another embodiment, the at least one marker is a spherical ball. In yet another embodiment, two markers are positioned within the distal end portion of the guide wire perpendicular to each other forming an X shape when viewed laterally along a length of the guide wire. 
         [0015]    These and other features of the guide wire of the subject invention and the manner in which it is manufactured and employed will become more readily apparent to those having ordinary skill in the art from the following enabling description of the preferred embodiments of the subject invention taken in conjunction with the several drawings described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein: 
           [0017]      FIG. 1  is a side schematic view of an exemplary embodiment of a flexible guide wire constructed in accordance with the present disclosure, showing a flexible portion between a rigid proximal end portion and a rigid distal end portion; 
           [0018]      FIG. 2  is an exploded side view of the flexible guide wire of  FIG. 1 , showing the flexible portion fixedly attached to the proximal and distal end portions; 
           [0019]      FIG. 3  is a side schematic view of the flexible guide wire, showing a bend in the flexible portion; 
           [0020]      FIG. 4  is a schematic view of the flexible guide wire in use; 
           [0021]      FIG. 5  is a perspective view of a distal end portion of an exemplary embodiment of a guide wire constructed in accordance with the present disclosure, showing a marker in the shape of a cylindrical wire; 
           [0022]      FIG. 6  is a top plan view taken in the direction of arrow  6  of the guide wire of  FIG. 5 ; 
           [0023]      FIG. 7  is a perspective view of a distal end portion of another embodiment of a guide wire constructed in accordance with the present disclosure, showing a marker in the shape of ball; 
           [0024]      FIG. 8  is a top plan view of the guide wire taken in the direction of arrow  8  of  FIG. 7 ; 
           [0025]      FIG. 9  is a perspective view of a distal end portion of yet another embodiment of a guide wire constructed in accordance with the present disclosure, showing two wire markers perpendicular to each other; and 
           [0026]      FIG. 10  is a top plan view of the guide wire taken in the direction of arrow  10  of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Referring now to the drawings wherein like reference numerals identify similar structural features of the claimed invention, there is illustrated in  FIG. 1  a flexible guide wire in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral  100 . The guide wire  100  is a one-piece longitudinal body  112  configured for use with a C-arm during an operating procedure. The guide wire  100  of the present disclosure has central axis with a proximal end portion  114  and an opposing distal end portion  116  aligned parallel to the central axis. Both the proximal and distal end portions  114 ,  116  are rigid shafts that provide stability to the guide wire  100 . 
         [0028]    A flexible portion  118  is positioned between the proximal and distal end portions  114 ,  116  and fixedly attached thereto. The flexible portion  118  includes a coiled tube formed generally perpendicular to the central axis. The flexible portion  118  allows the guide wire  100  to bend as needed. For example, in some embodiments, the flexible guide wire  100  can be introduced into a surgical site to allow for the introduction of instruments or implants over the flexible guide wire and the surgeon creates an incision in the body to provide access to the surgical site. 
         [0029]    In some embodiments, the described method is used to introduce a flexible guide wire to a pedicle of a vertebra to allow for the introduction of a bone drill, bone tap, implant driver, and a threaded spinal implant over the guide wire to the pedicle. It is important to note that such guide wires, including the flexible guide of the present invention, can realistically be used to guide instruments and implants into many locations within the body to allow for a surgeon to complete a surgical procedure. The present disclosure is not meant to limit the use of the flexible guide wire to the disclosed surgical application described herein. 
         [0030]    The distal end portion  116  has a larger longitudinal dimension than each of the flexible portion  118  and the proximal portion  114 . Preferably, the distal end portion  116  is approximately thirteen inches and the proximal end portion  114  is one inch. The flexible portion  118  includes a stainless steel flexible coil tube that is approximately five inches. Typical guide wires are too long and interfere with the c-arm and therefore need to be moved out of the way. The currently disclosed guidewire  100  is designed so as not to interfere with the c-arm view, however, those skilled in the art will readily appreciate that the length and diameters of each portion may vary depending upon the application. 
         [0031]    As shown in  FIG. 2 , the flexible portion  118 , the proximal portion  114  and distal portion  116  align to form one continuous body  112 . More specifically, an outer surface  118   a  of the flexible portion  118  has a diameter equal to a diameter of an outer surface  114   a  of the proximal portion  114  and an outer surface  116   a  of the distal portion  116 . This provides an easier entry/exit of the guide wire into the incision thereby causing fewer traumas and scarring for the patient. In addition, this provides sufficient column strength to manipulate the guide wire  100 . The rigid proximal portion  114  provides a smooth solid end. Further, the flexible portion  118  can be attached to the proximal and distal end portions  114 ,  116  by welding or the like. 
         [0032]    With reference to  FIGS. 3 and 4 , the flexible guide wire  100  is shown with a bend  122  in the flexible portion  118 . The coil tube of the flexible portion  118  is biased toward a straight configuration (as shown in  FIG. 1 ), yet sufficiently flexible to navigate an access pathway between vertebrae  132   a,    132   b  (as shown in  FIG. 4 ).  FIG. 4  illustrates the flexible guide wire  100  during an operating procedure. The location of insertion of the guide wire  100  is determined by radiographic means (e.g., C-arm flouroscope) and driven until the distal tip  124  reaches the desired location on the surface of a pedicle bone. The distal tip  124  is designed and configured to easily thread through for example, a pedicle screw to achieve accurate placement. 
         [0033]    The guide wire  100  of the present disclosure further includes at least one radio-opaque marker  126  placed in the distal end portion  116  near the distal tip  124  to allow a user a clear image of the location of the distal tip  124   a.  The marker  126  is a tantalum marker(s), including high density biocompatible material. Preferably, the marker  126  is mechanically placed within a generally solid core  112   a  of the longitudinal body  112  at the distal end portion  116  using standard machining methods. This prevents the marker  126  from interfering with the function and external design of the guide wire  100 . 
         [0034]    The marker  126  or markers can be placed in such a way that different configurations or shapes are created when an image is taken from the proximal portion  114 . With reference to  FIG. 1 , the marker  126  is shown as cylindrical rod/wire. Preferably, the marker  126  is positioned such that when the lateral image is taken, the marker  126 , best shown in  FIG. 6 , indicates the location of the distal tip  124   a  which is aligned with a central portion  128  of the marker  126 . 
         [0035]    Similarly, as shown in another embodiment of guide wire  200  of  FIGS. 7 and 8 , the marker  226  can be a spherical ball/bead placed within the longitudinal body  212  of the guide wire  200 . The spherical ball  226  is co-linear such that when viewed as a lateral fluoroscopy image a central region  228  (as seen in  FIG. 8 ) of the ball/bead  226  indicates the location of the distal tip  224   a.    
         [0036]    With reference to  FIGS. 9 and 10 , yet another embodiment of a guide wire  300  is shown with two markers  326   a,    326   b  positioned within the distal end portion  316 . The markers  326   a ,  326   b  are cylindrical rods/wires that are positioned perpendicular to one another. Viewing the guide wire  300  from a lateral fluoroscope illustrates an “X” shape such that the central region  328  indicates the location of the distal tip  324   a.  The markers  326   a,    326   b  are shown as two rod markers however the use of a plurality of markers is not limited to rod markers. For example, a rod and spherical ball can be used in combination. In another embodiment, multiple spherical balls can be placed in varying configurations to act as makers for taking measurements. Further, markers are not limited to placement within the distal end portion. The markers may be strategically placed throughout the longitudinal body to act as additional guiding features. 
         [0037]    While the marker(s) disclosed herein is shown and described for use on a guide wires those skilled in the art will readily appreciate the same can be implemented within spinal needles, temporary pins, or the like in which tip differentiation would be beneficial. Further, while the marker(s) shown and described herein are meant to represent specific shapes, those skilled in the art will readily appreciate that various shapes and configurations can be used to achieve the same results. 
         [0038]    While the subject invention has been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications may be made thereto without departing from the spirit and scope of the subject invention as defined by the appended claims.