Abstract:
An improved bone retractor tool includes a pair of arms pivotably connected to one in a pliers-like configuration and a pair of tissue engagement plates each having forward and rearward portions, each of the pair of tissue engagement plates mounted on the upper end of one of the pair of arms and extending generally parallel with one another when the pair of arms are in closed position. Forward bone engagement spikes are mounted on and extend forwards from the forward portions of the tissue engagement plates. A releasable securement mechanism is mounted on the pair of arms for releasably retaining the pair of arms in a selected position relative to one another, and a tensioning device is mounted on the pair of arms for tensioning the lower ends away from one another thereby forcing the pair of tissue engagement plates towards one another upon the securement mechanism being released.

Description:
CROSS-REFERENCE TO RELATED PATENTS 
     This application claims priority based on a provisional patent, specifically on the Provisional Patent Application Ser. No. 60/920,839 filed Mar. 30, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention is directed to surgical tools and, more particularly, to an improved bone retractor tool which includes a pair of pliers-like arms pivotably connected to one another, a pair of tissue engagement plates each mounted on an upper end of one of the arms and extending generally parallel with one another, the tissue engagement plates each further including forward bone engagement spikes which extend forward from the plates for entering into and being releasably retained within the bone of a person on whom an operation is being performed, a ratcheting securement mechanism mounted on one of the arms for releasably retaining the arms in a selected position relative to one another, and a tensioning device for tensioning the lower ends of the arms away from one another to force the tissue engagement plates towards one another when the ratcheting securement device is released. 
     2. Description of the Prior Art 
     Many different surgical procedures require access to the bones being operated upon, such as bone grafts and the like. One such procedure is commonly referred to as the “Evans” procedure, and it is a calcaneal lengthening procedure which requires a transverse bone cut through the distal part of the calcaneus. The bone then must be retracted to insert a graft wedge in the calcaneus to lengthen the lateral column and correct a flat foot. However, it is not simply a matter of accessing the bone and performing the graft, as the tissue and bone surfaces must be retracted to properly perform the operation. In fact, many different retractors have been developed and used but these invariably utilize the idea of inserting some element into the joint to retract the surfaces, which works well initially but then makes it difficult to access the desired surfaces to clean the cartilage off for a competent fusion. Also, a procedure that this gives advantage to is a fusion of two small joints. Impacting the spikes into the bone adjacent to the joint allows the joint to be opened and cleaned out without the retractor being in the way. After the joint is cleaned off, the holes from the spikes can be used for a staple to be inserted for fixation of the fusion or the previous Evans procedure. Basically, current methods and devices render the actual insertion of the graft a more difficult procedure because the retractor itself is in the way. 
     Therefore, an object of the present invention is to provide an improved bone retractor tool. 
     Another object of the present invention is to provide an improved bone retractor tool which includes a pliers-like handle and a pair of parallel plates, one mounted on each of the upper ends thereof, such that the plates may be spread apart from one another to open the graft area. 
     Another object of the present invention is to provide an improved bone retractor tool which, when spread apart, leaves the space between the plates open and unimpeded to facilitate access to the graft area. 
     Another object of the present invention is to provide an improved bone retractor tool which includes bone engagement spikes on the forward ends of the plates which enter the bone for easier separation of the joint for grafting of the tendon or ligament thereto and then are usable for insertion of a staple or the like therein to secure the bone joint in its original configuration. 
     Finally, an object of the present invention is to provide improved bone retractor tool which is relatively simple and durable in construction and is safe, efficient and effective in use. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved bone retractor tool which includes a pair of arms pivotably connected to one another intermediate the upper and lower ends thereof, the pair of arms pivotable between an open position and a closed position and a pair of tissue engagement plates each having forward and rearward portions, each of the pair of tissue engagement plates mounted on the upper end of one of the pair of arms and extending generally parallel with one another when the pair of arms are in the closed position. Forward bone engagement spikes are mounted on and extend forwards from the forward portions of the pair of tissue engagement plates. A releasable securement mechanism is mounted on at least one of the pair of arms for releasably retaining the pair of arms in a selected position relative to one another, and a tensioning device is mounted on at least one of the pair of arms for tensioning the lower ends of the pair of arms away from one another thereby forcing the pair of tissue engagement plates towards one another upon the securement mechanism being released. 
     The present invention thus provides numerous advantages over the prior art. For example, because access between the tissue engagement plates is not impeded by operative structures of the bone retractor tool, it is far easier for the doctor using the present invention to properly and efficiently perform the operation in which the present invention is being used. Furthermore, as the present invention can be releasably secured in many different spaced positions, it can be used for persons of all different sizes and in many different configurations. Finally, because the bone engagement spikes form holes in the bone which are then usable for insertion and retention of securement staples therein, formation of additional holes in the bone for the staples becomes unnecessary and therefore bone damage and trauma is minimized, which therefore renders the present invention a substantial improvement over the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the bone retractor tool of the present invention; 
         FIG. 2  is a top plan perspective view of the device showing how the movement of the arms coincides with movement of the engagement plates; 
         FIG. 3  is a detailed perspective view of the left and right tissue engagement plates of the present invention; and 
         FIG. 4  is a perspective view of the present invention being used to assist in a bone graft. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The bone retractor tool  10  of the present invention is shown best in  FIGS. 1-4  as including left and right arms  12  and  14  which are connected to one another at a pivoting joint  16  positioned towards the upper ends  18  and  20  of the left and right arms  12  and  14 . It is preferred that the left and right arms  12  and  14  have a similar shape and function as plier arms, with the dimensions of the left and right arms  12  and  14  being approximately six to eight inches in length, and further that they be constructed of stainless steel or the like so that the bone retractor tool  10  may be cleaned in an autoclave device or the like. 
     Mounted on the upper ends  18  and  20  of left and right arms  12  and  14  are left and right tissue engagement plates  30  and  32 , as shown best in  FIGS. 1-3 . In the preferred embodiment, each of the left and right tissue engagement plates  30  and  32  would be generally identical in size, shape and construction materials, and therefore the description of left tissue engagement plate  30  should be understood to apply equally to right tissue engagement plate  32 . In the preferred embodiment, left tissue engagement plate  30  would be generally rectangular in shape and have dimensions of approximately three quarters of an inch to one-half inches in length and one-half to one inch in height, with the forward end  34  of left tissue engagement plate  30  further including a pair of forwardly-extending bone engagement spikes  36   a  and  36   b . The bone engagement spikes  36   a  and  36   b  would each extend forward from the forward end  34  of left tissue engagement plate  30  and would be approximately one quarter to three quarters of an inch in length and further would be generally flat and in parallel alignment with the left tissue engagement plate  30  yet which would also include a pointed side configuration, as shown best in  FIG. 1 , such that each of the pair of forwardly-extending bone engagement spikes  36   a  and  36   b  has a configuration similar to that of a sharpened picket of a picket fence. It is preferred that the bone engagement spikes  36   a  and  36   b  be constructed of the same hardened stainless steel metal used to construct left tissue engagement plate  30  so that the bone engagement spikes  36   a  and  36   b  are very sturdy and strong and will easily enter into and engage the bone during use of the bone retractor tool  10  of the present invention. 
     Mounted on the lower end  24  of right arm  14  and extending towards the lower end  22  of left arm  12  is a ratcheting securement device  50  which, in the preferred embodiment, would include a pivotally mounted ratchet arm  52  mounted on a pivot mount base  54  connected to and mounted on the lower end  24  of right arm  14 . The ratchet arm  52  extends across and engages the lower end  22  of left arm  12  with the ratchet teeth  56  of ratchet arm  52  selectively engaging the lower end  22  of left arm  12  to retain the left arm  12  in a selected position relative to the right arm  14 , as shown best in  FIG. 2 . The ratchet arm  52  would be disengaged from the lower end  22  of left arm  12  by pivoting the ratchet arm  52  downwards on pivot mount base  54  to disengage the ratchet teeth  56  from the lower end  22  of left arm  12 . The left arm and right arm  12  and  14  may then be pivoted relative to one another about pivoting joint  16  without being releasably retained in a selected position by the ratcheting securement device  50 . 
     Finally, a tension device  60  is provided which extends between and connects the left and right arms  12  and  14  by a pair of tension spring plates  62  and  64  each mounted on one of the left and right arms  12  and  14 . The tension device  60  acts to bias the left and right arms  12  and  14 , specifically the lower ends  22  and  24  of left and right arms  12  and  14 , away from one another thus forcing the left and right tissue engagement plates  30  and  32  into contact with one another, as shown best in  FIGS. 2 and 3 . Of course, it should be noted that many different types of securement devices  50  and tension devices  60  may be used with the bone retractor tool  10  of the present invention which perform substantially the same functions, and such substitutions would be understood by one skilled in the art. 
     Also, it may be important to include a securement screw operative to releasably fix the pivoting joint  16  in a selected position, thereby providing two separate means by which the relative positions of left and right arms  12  and  14  may be fixed. The securement screw  26  would be mounted adjacent pivoting joint  16  and would be operative to tighten the pivoting joint  16  to prevent the pivoting motion of the left and right arms  12  and  14  relative to one another, and by merely untightening the securement screw  26 , the pivoting motion of left and right arms  12  and  14  via pivoting joint  16  may be resumed. 
     In use, the bone retractor tool  10  of the present invention would be inserted into the incision in the tissue above the location where the surgery is taking place, namely in the correct position to operate on the afflicted bone. The insertion begins with the left and right tissue engagement plates  30  and  32  in parallel contact with one another in closed position. The closed position is where the plates are approximately 1 cm apart from each other to place the osteotomy/bone cut or joint in between the plates. The forward portions of the left and right tissue engagement plates  30  and  32  are slid into the incision and the bone engagement spikes  36   a  and  36   b  on the left and right tissue engagement plates  30  and  32  are then tamped into the two adjacent bones (i.e. a joint) or into the ends of a cut bone approximately one-fourth of an inch, the arms are pushed together and the plates will distract the bone therein so that the bone graft may be inserted. It should be noted that it is generally preferred that the bone retractor tool  10  of the present invention be used with small joints, although it may be possible to use the invention with larger joints should the need arise. Once the bone engagement spikes  36   a  and  36   b  are inserted into the bone, the lower ends  22  and  24  of the left and right arms  12  and  14  are moved towards one another thus pivoting the left and right arms  12  and  14  about the pivoting joint  16  such that the left and right tissue engagement plates  30  and  32  and hence bone engagement spikes  36   a  and  36   b  move away from one another. The joint or cut bone will be distracted, thus opening access to the procedure location, and due to the configuration of the present invention, there is nothing between the left and right tissue engagement plates  30  and  32  and thus the inside of the bone and/or joint is fully exposed to allow unimpeded access to the bone. Also, as the left and right tissue engagement plates  30  and  32  are within the incision and the bone, the surrounding tissue and skin on the outer sides of the left and right tissue engagement plates  30  and  32  is pushed outwards, and due to the elasticity of the skin and tissue, the incision is widened without causing further damage to the skin and tissue. The incision is thus opened to provide access to the repair area and because the left and right tissue engagement plates  30  and  32  do not have any structure extending directly between them, there is nothing to interfere with access to the bone area being operated upon, unlike those devices found in the prior art. 
     Once the incision is opened the desired amount, the left and right arms  12  and  14  are secured in the selected positions by engagement of the securement screw  26  on the pivoting joint  16  or, preferably, by engagement of the ratcheting securement device  50  to secure the left and right arms  12  and  14  in the selected position. It is important to note that because the bone engagement spikes  36   a  and  36   b  are generally flat with a pointed side configuration, they engage substantially more bone surface thereby generally preventing the spikes from slicing through the bone as you retract, as is often encountered in using cylindrical spikes found in the prior art. This added feature allows the improved retractor of the present invention to be used in softer bone and obtain a better fusion site without creating as much damage to the adjacent bone. Also, the base of each of the left and right tissue engagement plates  30  and  32  from which the bone engagement spikes  36   a  and  36   b  extend forms a bone penetration stop face  38  which prevents the bone engagement spikes  36   a  and  36   b  from being over-inserted, thus preventing unintentional damage to the bone being operated upon. 
     Once the operation is completed, the bone retractor tool  10  is removed by releasing the securement screw  26  on the pivoting joint  16  or the ratcheting securement device  50 , pivoting the left and right arms  12  and  14  about the pivoting joint  16  to bring the left and right tissue engagement plates  30  and  32  towards one another, shifting the tool back and forth to release the bone engagement spikes  36   a  and  36   b  from the bone, then removing the left and right tissue engagement plates  30  and  32  from the incision by lifting them out of the incision. The bone or bones return to their pre-retracted state, and the surgeon or nurse may then put a staple across the joint/bone which utilizes the same holes that were formed by insertion of the bone engagement spikes  36   a  and  36   b . The operation then can be completed by the surgeon or nurse at their leisure. 
     It is to be understood that numerous additions, modifications and substitutions may be made to the bone retractor tool  10  of the present invention which fall within the intended broad scope of the above description. For example, the size, shape and construction materials used in connection with the bone retractor tool  10  may be modified or changed so long as the intended functional features are neither degraded nor destroyed. Furthermore, although the present invention has been described as being generally designed for use in connection with bone grafts or other such repairs, it should be noted that the bone retractor tool  10  may be used in many other types of operations as will be determined through use of the invention. Finally, it should be noted that the operative elements of the bone retractor tool  10  such as the bone engagement spikes  36   a  and  36   b  and the left and right tissue engagement plates  30  and  32  may be modified in size and shape depending on the intended usage of the present invention, and such modification would be understood by one skilled in the art of medical equipment and the use thereof. 
     There has therefore been shown and described a bone retractor tool  10  which accomplishes all of its intended objectives.