Abstract:
A sternal closure clamp device assembly for securing and retaining longitudinally divided halves of a sternum, the assembly having at least two sternal clamps retained by clamp receiving members, the clamp receiving members being joined by a linking assembly whereby the distance between the clamps can be adjusted and fixed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention generally relates to devices used to rejoin a human sternum that has been severed longitudinally, and more particularly relates to such devices that function in a clamping manner to retain the severed sternum portions in a closed and abutting relationship post-operatively. 
         [0002]    It is often necessary in surgical operations to longitudinally sever the patient&#39;s sternum so that the ribs may be spread to provide access to internal organs such as the heart. It is then necessary to secure the sternum halves together for post-operative recovery. Various closure techniques are used to accomplish this task. For example, holes may be drilled into the sternum halves and suture material passed through and tightened to cinch the sternum halves together. Apertured plates may be added to further rigidify the sternum post-operatively, with the suture material being passed through the apertures in the plate and the sternum. Encircling members may be wrapped around the sternum and tightened. Toothed bridging members extending across the cut line may be pressed into the sternum surfaces and/or secured with threaded rods extending between the sternal halves. 
         [0003]    Another sternal closure technique involves the use of expandable and contractible clamps having hook-like projections or engagement members on both ends, the clamp being positioned laterally relative to the sternal incision with the projections being disposed between adjoining rib pairs. The clamp is then linearly contracted or compressed to shorten the device and force the sternal halves together, the clamp typically comprising two members joined in a linear telescoping manner. Locking or securing means, either permanent or releasable, maintain the clamp in the contracted configuration. 
         [0004]    Examples of such techniques and devices are described in U.S. Pat. No. 3,473,528 to Mishkin et al., U.S. Pat. No. 4,201,215 to Crossett et al., U.S. Pat. No. 4,279,248 to Gabbay, U.S. Pat. No. 4,583,541 to Barry, U.S. Pat. No. 5,139,498 to Astudillo Ley, U.S. Pat. No. 6,051,007 to Hogendijk et al., U.S. Pat. No. 6,217,580 to Levin, U.S. Pat. No. 6,302,899 to Johnson et al., U.S. Pat. No. 6,540,769 to Miller, III, and U.S. Pat. No. 6,712,821 to Gabbay. 
         [0005]    While sternal clamps have proven very useful in stabilizing and rejoining a longitudinally severed sternum, there are situations where it would be beneficial to stabilize, rigidify and fix multiple sternal clamps relative to each other, such that in addition to clamping the sternum transversely the sternum is also longitudinally braced. It is an object of this invention to provide an array of sternal closure clamp devices that are joined together in the longitudinal direction parallel to the sternum such that a rigid framework or scaffold results. It is a further object to provide such an array where the separation distance between adjoining sternal clamps is adjustable in order to optimize the separation distance between adjoining sternal clamps. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention is in general an array of sternal closure clamp devices for post-operatively closing, securing and supporting a patient&#39;s sternum that has been longitudinally severed into two sternal halves. Each of the sternal clamps generally comprises a pair of slidingly interconnected body members that together form an expandable clamp, with one or more rearward-extending engagement members disposed on the outer end of one of the body members and one or more rearward-extending engagement members disposed on the outer end of the other body member. The engagement members are means to engage, secure or otherwise retain the sternal halves in an abutting relationship, with the engagement members having hooks, projections, fingers or the like disposed on their ends, whereby with the sternal clamps extending across the two sternal halves, the engagement members can be disposed against the outer edges of the sternal halves and between adjoining ribs to secure the sternal halves in an adjoining manner. 
         [0007]    Each of the adjoining sternal clamps are joined in the longitudinal direction (i.e., the direction parallel to the longitudinal axis of the sternum) by a linking assembly that defines a framework or scaffold for rigidly linking each of the sternal clamps in a fixed manner. Most preferably, the linking assembly comprises means for adjusting the distance between adjoining sternal clamps. 
         [0008]    Alternatively, in the case of a transverse cut through the sternum, the array can be oriented such that sternal clamps extend between rib pairs on either side of the sternum and the engagement members are disposed against the ribs themselves instead of the sternum. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of an array containing a pair of sternal clamps. 
           [0010]      FIG. 2  is a front view of the array embodiment of  FIG. 1 . 
           [0011]      FIG. 3  is a side view of the array embodiment of  FIG. 1 . 
           [0012]      FIG. 4  is a front view of an interior clamp receiving member for use in an array containing three sternal clamps. 
           [0013]      FIG. 5  is a front view of an array containing three sternal clamps. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    With reference to the drawings, the invention will now be described in detail with regard for the best mode and the preferred embodiment. The invention is an adjustable sternal closure clamp array used to close, secure and support a sternum post-operatively, the sternum having been severed longitudinally into left and right lateral sternal halves to provide access to the interior of the chest. The array insures that the sternum is stabilized laterally, such that the two sternal halves are pressed together, and longitudinally, such that the distance between adjoining sternal clamps remains fixed. In the preferred embodiment, the longitudinal distance between adjoining sternal clamps is adjustable to account for variation in patient size and other factors. 
         [0015]    The sternal clamps presented in the drawings are of the type of sternal clamp set forth in U.S. Publication No. US20060167458A1, the disclosure of which is incorporated herein by reference. These clamps are utilized as representations for any sternal clamp. It is to be understood however that the particular embodiment or structure of the sternal clamps of the invention is not limited to this particular type, structure or style. 
         [0016]      FIGS. 1 through 3  illustrate a paired array wherein two sternal clamps  10  are joined by a linking assembly  20 . The sternal clamps  10  each comprise a first sliding member  11  and a second sliding member  12 , with projection members  13  extending rearward from the outer ends of each sliding member  11  and  12 . This type of sternal clamp structure is well known in the art, and allows the sternal clamps  10  to be expanded such that the projection members  13  can be inserted between ribs and to the outside of the sternal halves. The clamps  10  are then contracted to force the sternal halves into abutment. 
         [0017]    The linking assembly  20  may be an integral member of fixed dimension, but most preferably is an assembly adjustable in length longitudinally, such that the distance between the sternal clamps  10  can be altered as required. The linking assembly  20  as shown in  FIGS. 1-3  comprises a first clamp receiving member  21  and a second clamp receiving member  22 , each having paired flanges  34  that secure and retain the sternal clamps  10 . Alternative means for retaining the sternal clamps  10 , such as through the use of fastening members, mechanical interlocks or the like, could also be utilized. Linking assembly adjustment means  23  for adjusting the length of the linking assembly  20  are provided, and may comprise as shown a first bridging member  24  and a second bridging member  25  which cooperate in a telescoping or sliding relationship to connect the clamp receiving members  21  and  22 , whereby the separation distance between sternal clamps  10  can be lengthened or shortened. As shown in this embodiment, first bridging member  24  comprises a pair of arm members  31  defining a central slot  32  and second bridging member  25  comprises a base member  35  with an internally-threaded screw receiving aperture (not shown). The screw receiving aperture receives screw member  27 , which in combination with ridge members  28  define a link securing means  26  for securely fastening the two bridging members  24  and  25  together. In this manner the sternal clamps  10  can be properly spaced in the longitudinal direction parallel to the sternum prior to clamping the sternal halves together. 
         [0018]      FIGS. 4 and 5  illustrate another embodiment of the invention in which the array comprises three sternal clamps  10 . In this embodiment, the linking assembly  40  comprises an interior clamp receiving member  41  having flanges  55  to retain the middle sternal clamp  10  of the grouping. The interior clamp receiving member  41  comprises first and second interior clamp bridging members  51  and  52  that extend to opposite sides of the interior clamp receiving member  41 . As illustrated in this embodiment, the first interior clamp bridging member  51  comprises a base member  53  with an internally-threaded screw receiving aperture  54 . The second interior clamp bridging member  52  comprises a pair of arm members  54  defining a central slot  56 . 
         [0019]    The first interior clamp bridging member  51  cooperates with the first outer clamp bridging member  43  of the first outer clamp receiving member  45 , and the second interior clamp bridging member  52  cooperates with the second outer clamp bridging member  44  of the second outer clamp receiving member  46 , to define clamp adjustment means for adjusting the length of the linking assemblies  40  in the same manner as clamp adjustment means  23  discussed above. Link securing means  47 , as described above, are provided for joining the first and second outer clamp receiving members  45  and  46  to the first and second interior clamp bridging members  51  and  52  of interior clamp receiving member  41 , such that the separation distance between the sternal clamps  10  can be adjusted as required. 
         [0020]    It is understood that equivalents and substitutions for certain elements described above may be obvious to those of ordinary skill in the art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.