Abstract:
A support fixture for setting a fractured distal radius includes a pair of lower support plates extending in opposite directions and a central support bracket movable away from the support plates. The support plates are pivotable relative to one another. To set a fractured distal radius, the forearm of the patient is attached to one of the support plates and his hand is attached to the other of the support plates. Then, the support plates are pivoted and clamped to achieve a desired positioning of bones adjacent to the fracture. Next, the central support bracket is moved away from the support plates, moving the patient&#39;s wrist until another desired positioning of these bones is achieved.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to an apparatus and method for use in the setting, or reduction, of a fractured distal radius. 
   2. Background Information 
   The fracture of the distal radius is one of the most common human fractures, occurring in as many as 350,000 people per year in the United States alone. The application of an extension force and lateral depression for reducing a fracture of the distal radius is well known, having been described in the 1901 edition of Gray&#39;s Anatomy in the following manner, “The treatment consists in flexing the forearm, and making a powerful extension from the wrist and elbow, depressing at the same time the radial side of the hand, and retaining the parts in that position by well-padded pistol-shaped splints.” 
   Conventional methods for reducing a fractured distal radius require that the physician or surgeon must be helped by an assistant during the process. Two or more people are required to apply the extension force to the hand into a configuration providing an additional extension force at the site of the fracture, and to further manipulate any bone fragments or separated sections into position. What is needed is a convenient fixture for applying such forces during the process of setting this type of fracture, so that a physician or surgeon can reduce the fracture without requiring the help of an assistant. 
   U.S. Pat. No. 6,123,705 describes a support fixture for setting a fractured distal radius includes a housing having a strap for fastening the fixture to the patient&#39;s forearm, a sliding section, sliding within the housing as a screw is rotated, and a pivoting section extending from a distal end of the sliding section. The sliding section also includes a structure for supporting the patient&#39;s wrist. The distal end of the pivoting section includes a pair of fingertraps. Two of the patient&#39;s fingers are held in the fingertraps, while an extension force is applied between his forearm and hand through the rotation of the screw, and while his hand is twisted by adjusting the angle of the pivoting section to increase the gap between fractured sections of bone, causing reduction of the fracture to occur. 
   U.S. Pat. No. 5,074,291 describes a hand traction surgical table having an adjustable surgical table frame. An arm board having an upper surface and a lower surface is mounted on the surgical table frame, thereby providing an operating surface for surgical procedures on the wrist and forearm. A pulley is mounted on the surgical table frame, and a reduction force applying cable is mounted through the pulley. A finger retention device is mounted at a first end of a cable and a force applicator is mounted at a second end of the cable so that a predetermined reduction force can be applied to the patient&#39;s hand. 
   U.S. Pat. No. 5,006,120 shows the use of a device including a weight, a pulley, and fingertraps to hold a patient&#39;s arm extended, reducing a distal fracture of the radius during an operation installing, with a number of screws and blades extending into the bone, a plate spanning a fracture of the distal radius. What is needed, is a convenient means to support the wrist, from below and from a side, in a manner that the angle of the wrist can be controlled during the setting of such a fracture, and, for example, during the installation of a plate spanning a fracture of the distal radius. 
   A number of other patents, such as U.S. Pat. Nos. 4,554,915, 5,545,162, 5,741,251, and 6,197,027 describe external fixation frames which are used, for example, for immobilizing bone segments adjacent a fracture or joint. Again, what is needed is a convenient means to support the wrist in a manner that the angle of the wrist can be controlled during the installation of an external fixation frame. 
   SUMMARY OF THE INVENTION 
   According to a first aspect of the invention, there is provided a support fixture for setting a fractured distal radius of a forearm. The support fixture includes a central mounting structure, a pair of support brackets a clamping member, and a central support bracket. The pair of support plates extends along a first plane in opposite directions from the central mounting structure and pivotable on the central mounting structure in the first plane relative to one another. The clamping member is engageable to hold the support plates in a fixed relationship with one another. The central support bracket extends from the central mounting structure spaced apart from the support plates and is movable perpendicular to the first plane along the central mounting structure. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1  is a perspective view of a support fixture built in accordance with the present invention; 
       FIG. 2  is a vertical cross-sectional elevation of the support fixture of  FIG. 1 , taken through a central mounting structure therein; 
       FIG. 3  is a bottom plan view of a support plate within the support fixture of  FIG. 1 ; 
       FIG. 4  is a vertical cross-sectional elevation of the support plate of  FIG. 3 , taken as indicated by section lines IV—IV therein; and 
       FIG. 5  is a perspective view of the support fixture of  FIG. 1  in use to set a fracture of a distal radius. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a perspective view of a support fixture  10  built in accordance with the present invention. The support fixture  10  includes a first support plate  12 , a second support plate  14 , a central support bracket  16 , and a central mounting structure  18  mounting the support plates  12 ,  14  to pivot relative to one another and further mounting the central support bracket  16  to move in or opposite the direction of arrow  20 , perpendicular to a plane in which the support plates  12 ,  14  extend. 
     FIG. 2  is vertical cross-sectional elevation of the support fixture  10 , taken through the central mounting structure  18  to show the arrangement thereof. The central mounting structure  18  includes a clamping member  22  having a threaded surface  24  engaging a threaded hole  26  within the first support plate  12 . The clamping member  22  additionally includes a bearing surface  28 , axially aligned with the threaded surface  24  to extend through a clearance hole  30  in the second support plate  14 , and a knob  32  used to rotate the clamping member  22 . When the threaded surface  24  is loosely held (i.e., not tightened) within the threaded hole  26  of the first support plate  12 , the second support  12  pivots on the bearing surface  28 , relative to the first support plate  12  within the plane in which the support plates  12 ,  14  extend. Threads from the threaded hole  26  may extend around some or all of the bearing surface  28 . When the threaded surface  24  is tightened within the threaded hole  26 , a shoulder  34  of the clamping member  22  holds the lower surface  36  of the upper support plate  14  against the adjacent upper surface  38  of the support plate  12 , preventing rotation of these plates  12 ,  14  relative to each other. 
   The central mounting structure  18  also includes a bracket screw member  40 , rotatably mounted on pivot shaft portion  42  of the clamping member  22 . The bracket screw member  40  includes an externally threaded surfaces  44  engaging a threaded hole  46  within the central support bracket  16 , so that rotation of the bracket screw member  40  relative to the central support bracket  16  moves the central support bracket  16 , relative to the bracket screw member  40 , in or opposite the direction of arrow  20 , perpendicular to the plane in which the support plates  12 ,  14  extend. 
   Each of the support plates  12 ,  14  has an upper surface  48  for supporting either the hand or forearm of the patient. The central support bracket  16  has a support surface  50  for supporting the wrist of the patient as it is elevated above the lower surfaces of the hand and forearm and a wall  52  extending outward from the support surface  50  to restrain rotation of the central support bracket  16  as bracket screw member  40  is rotated by means of a knob  54  to move the central support bracket  16  in or opposite the direction of arrow  20 . 
     FIG. 3  is a fragmentary bottom plan view of the second support plate  14 , showing a pattern of radially-extending ridges  56  and grooves  58  on the lower surface  36  of this plate  14  around the clearance hole  28 . 
     FIG. 4  is a fragmentary vertical cross-sectional view of the second support plate  14 , taken as indicated by section lines IV—IV in  FIG. 3 , showing adjacent ridges  56  and grooves  58 . 
   Referring to  FIGS. 2–4 , the lower surface  36  of the second support plate  14  and the upper surface  38  of the first support plate  12  each include similar, mating patterns of ridges  56  and grooves  58 , which extend below and above the adjacent flat area  60  of the lower surface  36 . When these surfaces  36  and  38  are held together by tightening the threaded surface  24  of the clamping member  22  within the threaded hole  26  of the first support plate  12 , the ridges  56  and grooves  58  form matching serrations that prevent pivoting movement of the support plates  12 ,  14  relative to one another. That is, the engagement of ridges  56  of the second support plate  14  within grooves  58  of the first support plate  12 , together with the engagement of ridges  56  of the first support plate  12  within grooves  58  of the second support plate  14 . On the other hand, when the surfaces  36  and  38  are allowed to move apart by loosening the threaded surface  24  of the clamping member  22  within the threaded hole  26  of first support plate  12 , the ridges  56  of the first support plate  12  can move past the ridges  56  of the second support plate  14 , so that the support plates  12 ,  14  may be pivoted relative to one another. The surfaces  36 ,  38  additionally include recessed annular grooves  62  to accommodate misalignment between the patterns of ridges  56  and grooves  58  on the first and second support plates  12 ,  14 . 
   The lower surface  36  of the second support plate  14  preferably includes a waffle pattern of cavities  64  extending upward to webs  66  extending along the upper surface  48  of this plate  14 . Preferably, the lower surface  68  of the first support plate  12  additionally includes a similar pattern of cavities  60 . These cavities  60 , reduce the amount of plastic resin needed to produce parts having sufficient stiffness and simplify the process of molding parts with suitable stiffness. 
   The process for setting, or reducing a fractured distal radius in accordance with the present invention will now be discussed in reference to  FIG. 5 , which is a perspective view of the support fixture  10  as used to perform this process with the forearm  70  and hand  72  of the patient each being fastened to the support plates  12 ,  14  of the support fixture  1  by means of a web  74 , and with the wrist  76  disposed adjacent to the central support bracket  18 . For example, each of the webs  74  may be a strip of self-adherent bandage sold under the registered trademark MEDI-RIP by Hartmann-Conco of Rock Hill, S.C. Such a material clings to itself when wrapped tightly more than once around the forearm  70  or hand  72 . Alternately, the webs  74  may each be formed as part of the apparatus  10 , with two parts of a textile web being joined by loop and hook closure pads sold under the registered trademark VELCRO. The forearm  70  and hand  72  are oriented on the apparatus  10  so that the central mounting structure  18  is disposed laterally outward from the forearm  70 , with the hand being attached to either the first support structure  12 , as shown in  FIG. 5 , or the second support structure  14 , to place the central mounting structure  18  outside the forearm  70 , regardless of whether the right or left forearm is being treated. 
   After the forearm  70  and hand  72  are fastened to the apparatus  10  by means of the webs  74 , a process of manipulation of the apparatus  10  to set the fracture is begun, preferably to be carried out with the aid of fluoroscopic visualization of the fracture area to determine when a desirable relationship among the fractured bone structures has been attained. The various elements of the apparatus  10  are preferably composed of materials, such as thermoplastic resins, that are transparent to the radiation used for fluoroscopic visualization. 
   This process of manipulation of the apparatus  10  begins with manually adjusting the angular relationship the first and second support plates with the clamping member loosened to permit relative pivoting movement of these plates. First, the support plates  12 ,  14  are manually pivoted relative to one another so that the hand  72  is pivoted laterally outward, in the direction of arrow  78 . When the desired relationship of the bones in the fracture area has been attained in this way, preferably as verified by fluoroscopic visualization, the support plates  12 ,  14  are locked together by tightening the clamping member  22  by rotating the knob  32 . Then, the central support bracket  16  is moved away from the lower support plates  12 ,  14  by rotating the knob  54  to turn the bracket screw member  40 . When the central support  16  has moved the wrist  76  so that the bones adjacent the fracture are moved into a desirable position, again preferably as verified through fluoroscopic visualization, this manipulation process is determined to have been completed. 
   At this point, the position of bones adjacent the fracture may by further maintained by attaching an external fixation device, such as the device described in U.S. Pat. No. 6,197,027, the disclosure of which is incorporated herein by reference, so that various pins extend into these bones. Alternate fixation means, including the attachment internal of screws and plates to hold the bones together, as well known to those skilled in the art, may alternately be employed. Portions of the webs  74  may be cut away to clear surgical sites, or two or more straps may be used in place of a web, so that access to surgical sites will not be impaired. 
   While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention.