Abstract:
An apparatus is provided for performing spinal surgery having a handle assembly, a screw guide, and a retractor. A shaft is provided with a handle, a neck portion and a connecting portion. The screw guide is provided with a connecting element coupled to the connecting portion of the handle assembly. A retractor for retracting tissue is coupled to the screw guide, wherein the neck portion of the handle assembly is provided with a spring loaded sleeve adapted to engage one of a plurality of holes positioned on a portion of the connecting element. The connecting portion is pivotably coupled to the connecting element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to provisional application Ser. No. 61/178,710 filed on May 15, 2009, which is incorporated herein in it&#39;s entirety by reference thereto. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an instrument for guiding a screw and retracting soft tissue. 
     BACKGROUND OF THE INVENTION 
     During spinal surgery, there is a need to guide a screw into the spine and retract soft tissue around the surgery area. Previously, specific instruments are used to guide a screw into the spine and other specialized instruments are used to retract the soft tissue around the surgery area. 
     There is a need for a single instrument that allows the screw to be guided as well as retract soft tissue. 
     SUMMARY OF THE INVENTION 
     An apparatus for performing spinal surgery having a handle assembly, a screw guide, and a retractor. A shaft is provided with a handle, a neck portion and a connecting portion. The screw guide is provided with a connecting element coupled to the connecting portion of the handle assembly. A retractor for retracting tissue is coupled to the screw guide, wherein the neck portion of the handle assembly is provided with a spring loaded sleeve adapted to engage one of a plurality of holes positioned on a portion of the connecting element. The connecting portion is pivotably coupled to the connecting element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more readily understood with reference to the embodiments thereof illustrated in the attached drawing figures, in which: 
         FIGS. 1 and 2  illustrate a front view and a side view of the drill guide and retractor system according to the present invention; 
         FIGS. 3 and 4A-4C  illustrate exploded and perspective views of the handle assembly of the present invention; 
         FIG. 5  illustrates an exploded view of the connection element of the handle assembly according to the present invention; 
         FIG. 6  illustrates the screw guide and the connection element according to the present invention; 
         FIGS. 7 and 8  illustrate exploded views of the screw guide according to the present invention; and 
         FIGS. 9 and 10  illustrate perspective views of the retractor according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the invention will now be described. The following detailed description of the invention is not intended to be illustrative of all embodiments. In describing embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. 
       FIGS. 1 and 2  illustrate various views of the screw guide and soft tissue retractor system  10  according to one embodiment of the present invention. As illustrated in  FIGS. 1 and 2 , the system  10  is configured with a handle assembly  12 , a screw guide  14 , and a retractor  16 . In one embodiment, the screw guide and soft tissue retractor system is utilized to stabilize the facets of the spine as an aid to fusion of adjacent vertebrae. 
       FIGS. 3 and 4  illustrate exploded views of the handle assembly  12  of the present invention. The handle assembly  12  is composed of a handle portion  18 , a sleeve  20 , and connecting element  22 . The upper portion of the handle assembly is angled away from the blade and is designed not to interfere with the handle assembly of the drill guide. The handle angles away to avoid contact with soft tissue. The handle is also removable from the blade to eliminate interference when using other instrumentation. 
     The sleeve  20  is adapted to enclose the shaft portion  24  of the handle assembly  12 .  FIGS. 3-5  illustrate the spring loaded sleeve  20  which works with the incremental cuts in a manner so that the spring loaded sleeve  20  is designed to be pulled back towards the handle to disengage the handle  12  from a standard orientation. The sleeve  20  will then snap into the next slot available automatically. This mechanism is a push button release and spring loaded lock which is used to secure the many proximal attachments that can be inserted into the handle assembly. The spring-loaded lock has a dowel  28  that enters one of the plurality of holes  30  which is designed to snap into a mating hole in the attachments. When adding an attachment, the part is automatically locked into the handle assembly. To remove the attachment, the user will push the button, which removes the dowel from the circular through way, thereby allowing the user to easily remove that attachment. 
     More specifically, the shaft portion  24  is provided with a spring  26  which the sleeve  20  encompasses when the system is assembled. The sleeve  20  is also provided with a dowel  28  and is designed to translate along the shaft portion  24 , via the spring mechanism provided on the shaft portion  24  of the handle assembly  12 . The dowel  28  is designed and configured to engage one of a plurality of holes  30  positioned on the connecting element  22 . The handle assembly  12  is adapted to translate angularly within the connecting element  22 . Once a position is selected for the handle assembly  18 , the sleeve  20  is translated and the dowel  28  is fit into one of the plurality of holes  30 . The connecting element  22  and handle assembly  12  may be coupled together through the use of pin  32  which extends through the hole  30  of the shaft portion  24  which secures the connecting element  22  to the handle assembly  12 . 
       FIG. 5  illustrates an exploded view of the connecting element  22  according to the present invention. The connecting element  22  is configured to receive the shaft portion  24  of the handle assembly  12  in slot  34 . As mentioned above, pin  32  is utilized to couple the shaft portion  24  to the connecting element  22 . The shaft portion  24  once connected to the connecting element is pivotable so that the handle assembly  12  may be rotated into different predetermined locations. Also, on the connecting element  22 , there is provided a mechanism for the screw guide  14  to be coupled to the connecting element  22 , which is discussed in greater detail with regard to  FIG. 6 . 
     A spring loaded pin assembly  38  is utilized in another portion of the connecting element  22  to enable access to instruments other than the screw guide. For instance through hole  42  may be used to provide access to the surgical site for instruments such as a k-wire. Cannulas that enable this can be adapted to fit into the through hole  42 . The spring loaded pin assembly  38  is configured to actuate pin  40 . Pin  40  extends through the inner wall of the through hole  42  and extends out through hole  44 . When the spring loaded pin assembly  38  is engaged, pin  40  is retreated from the through hole  36 , thereby enabling a cannula or any other instrument to be positioned within the through hole  42 . Once the instrument is positioned in the through hole, the spring loaded pin assembly  38  is disengaged, allowing pin  40  to engage the instrument and thereby locking the instrument within the connecting element  22 . 
       FIG. 6  illustrates the screw guide  14  attached to the connecting element  22  of the present invention. The screw guide  14  is designed as a cannula that attaches to the connecting element  22 . More specifically, the screw guide  14  is configured and dimensioned to be cylindrical in shape which enables a surgeon an easier access for insertion into soft tissue. The geometry of the screw guide  14  is also configured so that a continuous smooth surface is provided to eliminate the change of damaging the surrounding soft tissue. The screw guide  14  is further provided with protrusions on the bottom surface of the guide  14  to allow the guide to be docked or articulate on the fracture site. The distal end of the screw guide  14  has a bottom surface that matches the curve of the cervical spine in this particular embodiment of the invention. Although, the distal end may be configured to match the curve of any portion of the spine. The matching curvature of the distal end aides in establishing the trajectory of the instruments and implants. 
     Now turning to  FIGS. 7 and 8 , the screw guide  14  will be discussed in greater detail. As illustrated in  FIGS. 7 and 8 , a connecting element  46  is provided on the top surface of the guide  14 , and this connecting element  46  is the locking mechanism by which the screw guide  14  is attached to the handle assembly  12 . The connecting element  46  is configured to fit into the slot  48  provided on the upper surface of the connecting element  22 , as seen in  FIG. 6 . The screw guide  14  is also provided with rails  50  on the top surface that are spaced apart and angled to allow the screw guide to couple with the retractor. At the distal end of the guide, there is provided a protrusion  52  which is coupled to the distal end of the guide by pins  54 , that is used to dock or articulate the screw guide  14  near or about the surgical site. The distal portion of the guide  14  also is configured to have a curvature which enables accessing the surgical site easier. The guide  14  is also configured with three radioopaque rods  56  with two rods being placed 180 degrees apart and one being positioned vertically, as illustrated in  FIGS. 7 and 8 . The rods  56  are used in conjunction with x-ray imaging to provide alignment verification through lateral and anterior-posterior x-ray images. 
       FIGS. 9 and 10  illustrate the top and bottom views of the soft tissue retractor  16  in greater detail. The retractor  16  is utilized to access the surgical site and providing a safe cavity for inserting of the screw guide. The soft tissue retractor  16  is typically the first instrument assembled to the screw guide and the first instrument used. It is used for reaching the fracture side initially, and creates a safe cavity to the insert the screw guide. The tip of the soft tissue retractor  16  has a concave shape to match the anterior geometry of the normal cervical vertebral body. This allows the soft tissue retractor to be seated on the anterior body instead of having a flat tip that unstablizes the retractor. 
     The soft tissue retractor  16  also includes at least three radio opaque balls  58  that is pressed into the surface of the soft tissue retractor  16  that allows the user to verify the retractor&#39;s position through lateral and anterior-posterior imaging. At least two of the balls  58  will be visible when the retractor is level in the lateral plane while the ball at the tip will be visible when the retractor has reached the vertebral body. The retractor blade  16  is also composed of a radiolucent material so that the blade itself is visible in the x-ray images. 
     As further illustrated in  FIG. 9 , axial slots  60  are provided on the bottom portion of the retractor  16 . These slots  60  are configured and designed to couple the retractor  16  with the rails of the screw guide. It should be noted that any mechanism for attaching the rails to the screw guide can be used. For example, a dove tail type connection can be used couple the screw guide to the retractor  16 .  FIG. 10  also illustrates the top portion of the retractor. In this particular embodiment, a connection assembly  62  is provided for attaching the retractor to another instrument such as a hex driver so that the surgeon may remove the retractor without removing the screw guide from the screw guide assembly. 
     While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations can be made thereto by those skilled in the art without departing from the scope of the invention as set forth in the claims.