Abstract:
In a surgical severing instrument comprising two cutting jaws movable relative to each other from an open position to a cutting position by means of hand grips movable relative to each other, in order to improve the handling, in particular, of the severed parts, it is proposed that two clamping jaws movable relative to each other from an initial position to a clamping position be arranged alongside the cutting jaws, and that actuators be provided on the surgical severing instrument, which, upon movement of the cutting jaws from the open position to the cutting position, simultaneously move the clamping jaws from their initial position to the clamping position.

Description:
[0001]    The present disclosure relates to the subject matter disclosed in German application number 10 2009 007 455.4 of Feb. 4, 2009, which is incorporated herein by reference in its entirety and for all purposes. 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a surgical severing instrument having two cutting jaws movable relative to each other from an open position to a cutting position by means of hand grips which are movable relative to each other. 
         [0003]    Such severing instruments are often of pliers-like construction and serve to sever tissue or parts of implants, for example, for severing protruding wire pins or the like. The cutting jaws may be normal cutting arms of scissors-like construction or in the fashion of cutting pliers. In all cases, the cutting jaws are moved towards each other with opposed cutting edges and can thereby sever material that is arranged between them. 
         [0004]    In particular, when severing parts of implants, it is necessary to collect the severed parts carefully and remove them from the body when the operation takes place inside the body. 
         [0005]    A pliers-like cutting element of this kind is described, for example, in DE 195 34 831 C2. 
         [0006]    Surgical severing instruments are also known, which are combined with clamping jaws, the function of the clamping jaws consisting, for example, in grasping tissue or objects which are to be severed. In known instruments of this kind, separate actuating members are provided for actuating the clamping jaws and for actuating the cutting jaws. The actuating members are actuated separately using the hand grip, so that the surgeon can carry out a clamping and a cutting procedure successively (U.S. Pat. No. 6,358,268 B1; U.S. Pat. No. 4,600,007). This is awkward and may also result in cutting procedures being carried out without the cut-off parts being secured by the clamping jaws. 
         [0007]    The object of the invention is to so construct a generic surgical severing instrument that the handling while collecting severed parts can be improved with it. 
       SUMMARY OF THE INVENTION 
       [0008]    This object is accomplished, in accordance with the invention, in a surgical instrument of the kind described at the outset by two clamping jaws movable relative to each other from an initial position to a clamping position being arranged alongside the cutting jaws, and by actuators being provided on the surgical severing instrument, which, upon movement of the cutting jaws from the open position to the cutting position, simultaneously move the clamping jaws from their initial position to the clamping position. 
         [0009]    Accordingly, upon actuating the cutting jaws, the clamping jaws are also closed as a consequence thereof, i.e., moved to the clamping position, so that it is ensured that during the severing or cutting by means of the cutting jaws, the severed parts are definitely grasped by the clamping jaws without the user having to specially actuate the clamping jaws using separate handling members. By providing actuators on the severing instrument, actuation of the clamping jaws is bound to occur for each cutting procedure. 
         [0010]    In particular, it may be provided that the cutting jaws and/or the clamping jaws are movable relative to each other by being pivoted about a pivot axis. The cutting jaws and the clamping jaws are preferably mounted coaxially. 
         [0011]    It is particularly advantageous for the clamping jaws to be each connected to an actuating lever, and for the clamping jaws to be moved from the initial position to the clamping position by the actuating levers being brought closer together. This results in a pliers-type instrument. 
         [0012]    It is expedient for the actuators to be arranged on the hand grips of the severing instrument and to engage the actuating levers of the clamping jaws. 
         [0013]    In particular, it may be provided that the actuators are projections on the hand grips, which abut on the outer sides of the actuating levers. 
         [0014]    In accordance with a particularly preferred embodiment, it is provided that a spring element which attempts to move the cutting jaws or the clamping jaws to their open position or initial position engages the severing instrument and/or the clamping jaws. Accordingly, the severing instrument is transferred to the cutting position against the action of these spring elements, and, similarly, the clamping jaws are transferred to their clamping position against the action of the spring element. Prior to the actuation, both the cutting jaws and the clamping jaws are therefore open, i.e., they are located in the open position or in the initial position. 
         [0015]    In accordance with a further preferred embodiment, a locking device for enabling movement of the clamping jaws from the initial position to the end position, but not in the reverse direction, is associated with the clamping jaws. The clamping jaws thus remain in the clamping position after being moved into it, and they therefore retain between them parts clamped between the clamping jaws and severed after the cutting procedure. The cutting jaws can be moved back into the open position again after a cutting procedure, but the clamping jaws remain in the closed clamping position also after completion of the cutting procedure and after opening of the severing instrument. 
         [0016]    For example, the locking device may be constructed as a latching bar which is operative between the actuating levers of the clamping jaws, as is known per se in pliers-type surgical instruments. 
         [0017]    In another preferred embodiment, it is provided that the locking device is formed by latching surfaces on the clamping jaws, which are arranged concentrically with a pivot axis of the clamping jaws and abut on each other. In particular, these latching surfaces may be fitted with saw-tooth-shaped teeth, which allow the latching surfaces to slide past each other in one direction, but not in the reverse direction. 
         [0018]    It is particularly advantageous for the clamping jaws and possibly the actuating levers to be constructed as a structural unit which is detachably connectable to the severing instrument. Firstly, it is thus possible, after detachment of this structural unit from the severing instrument, to use the severing instrument without this structural unit, i.e., in the usual manner as a simple severing instrument without any additional clamping device, and, secondly, it is possible to fit a severing instrument with a structural unit which brings about the clamping of the severed components, and to construct this structural unit as a disposable part, for example, as a plastic part, in which case, the severing instrument is fitted with a new structural clamping unit for each operation. 
         [0019]    In particular, the structural unit may be in the form of pliers having two arms pivotably connected to each other, which form actuating levers and carry the clamping jaws at their distal ends. This pliers-like structural unit may possibly have a significantly shorter length than the severing instrument, it sufficing for the actuating levers of the structural clamping unit to extend over part of the length of the hand grips of the severing instrument. 
         [0020]    In accordance with a preferred further development of the severing instrument, it may also be provided that the cutting jaws carry deforming projections which, when the components arranged between the cutting jaws are being severed, bend locking elements arranged on the components or on elements carried by the components and thereby lock the locking elements relative to other components or elements. Such a severing instrument not only holds the severed components securely by means of the closed clamping jaws but also locks the parts remaining, for example, on an implant relative to one another by deforming or bending locking elements provided thereon by means of the deforming projections arranged on the cutting jaws. The cutting jaws are therefore given a double function, namely the function of severing implant parts or the like, on the one hand, and the function of deforming or bending parts in order to lock them, on the other hand. 
         [0021]    The following description of preferred embodiments of the invention serves in conjunction with the drawings for further explanation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  shows a perspective view of a pliers-type severing instrument with clamping pliers in engagement during the shortening of metal pins on an intervertebral implant; 
           [0023]      FIG. 2  shows a perspective view of the severing instrument of  FIG. 1  with open cutting jaws and open clamping jaws; 
           [0024]      FIG. 3  shows a view similar to  FIG. 2  with closed cutting jaws and closed clamping jaws; 
           [0025]      FIG. 4  shows a view similar to  FIG. 3  with cutting jaws opened after the cutting procedure and clamping jaws still closed; 
           [0026]      FIG. 5  shows a perspective view of the severing instrument of  FIG. 2  in the area of the cutting jaws and the clamping jaws; 
           [0027]      FIG. 6  shows a perspective view of an intervertebral implant with locking elements prior to a cutting procedure and prior to the bending of the locking elements; 
           [0028]      FIG. 7  shows a view similar to  FIG. 6  after the severing of implant parts and after the bending of locking elements; and 
           [0029]      FIG. 8  shows a side view of a modified embodiment of a severing instrument in the area of the cutting jaws and the clamping jaws with a locking device in the form of latching surfaces lying with surface-to-surface contact against one another. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    The drawings show a pliers-type severing instrument  1  with two cutting jaws  2 ,  3  which are mounted for pivotal movement relative to each other. The cutting jaws  2 ,  3  are engaged by an arm  4  and  5 , respectively. The arms  4 ,  5  are also pivotably connected to each other and also pivotably connected to the cutting jaws  2  and  3 , respectively, so that upon pivotal movement of the two arms  4 ,  5  relative to each other, the two cutting jaws  2 ,  3  are also pivoted relative to each other about their common pivot bearing. 
         [0031]    The two cutting jaws  2 ,  3  are pressed apart by leaf-shaped spring elements  6 ,  7  arranged between the two arms  4 ,  5 , so that upon pressing together the two arms  4 ,  5 , the arms  4 ,  5  have to be pressed together against the force of these spring elements  6 ,  7 . Accordingly, the arms  4 ,  5  are normally in the open position in which they are maximally spaced from each other, and, as a result, the cutting jaws  2 ,  3  are also in an open position in which cutting edges  8 ,  9  on the cutting jaws  2 ,  3  are maximally spaced from each other. Such a severing instrument  1  in the form of cutting pliers is known per se and can be used for severing portions of tissue or implant parts or the like. In the embodiment shown in the drawings, this severing instrument  1  is used to sever and thereby shorten metallic pins  10 ,  11  which extend through an intervertebral implant  12 , after implantation into the intervertebral space between two adjacent vertebral bodies  13 ,  14 . Of the intervertebral implant  12  shown in the drawings, it is essentially the pins  10 ,  11  that are of importance, and, therefore, the further construction of the intervertebral implant  12  will not be explained in greater detail. 
         [0032]    After insertion of the intervertebral implant  12 , the pins  10 ,  11  protrude from it and must be shortened. This is done with the severing instrument  1 . 
         [0033]    The severing procedure is carried out close to an end plate  15  of the intervertebral implant  12 , through which the two pins  10 ,  11  pass. For the severing of the pins, this end plate  15  is placed in a recess  16 ,  17  of the two cutting jaws  2 ,  3 , which is located immediately beside the cutting edges  8 ,  9  of the cutting jaws  2 ,  3  ( FIG. 5 ), so that an exact positioning of the intervertebral implant  12  and the pins  10 ,  11  protruding from it relative to the cutting jaws  2 ,  3  is thereby enabled. 
         [0034]    Arranged on the severing instrument  1  on the side of the cutting jaws  2 ,  3  located opposite these recesses  16 ,  17  is a clamping instrument  18 , also of pliers-type construction, which has two clamping jaws  19 ,  20  pivotably connected to each other, which are fixedly connected to an arm-like actuating lever  21  and  22 , respectively. The actuating levers, each carrying a clamping jaw, are pivotably connected to each other by a bearing shaft  23  extending transversely through them. They intersect at the bearing point, so that the clamping jaws  19 ,  20  can be pivoted out of an open initial position into a closed clamping position when the two actuating levers  21 ,  22  are pivoted relative to each other. There is also provided between the actuating levers  21 ,  22  an elastic spring element  24 , which pivots the actuating levers  21 ,  22  into the open position and which has to be deformed when the actuating levers  21 ,  22  are pivoted relative to each other. 
         [0035]    This pliers-type clamping instrument  18  is arranged at the side of the severing instrument  1  in such a way that the pivot axis of the clamping jaws  19 ,  20  defined by the bearing shaft  23  and the pivot axis of the two cutting jaws  2 ,  3  are arranged coaxially, so that in the closed state the cutting edges  8 ,  9  of the cutting jaws  2 ,  3  and the clamping surfaces of the clamping jaws  19 ,  20  are located in a common plane. 
         [0036]    Arranged on the two arms  4 ,  5  are side pins  25 ,  26 , which engage the outer sides of the two actuating levers  21 ,  22 , which have depressions  27 ,  28  for receiving the pins  25 ,  26 . The clamping instrument  18  may be held on the severing instrument  1  for detachment in its entirety therefrom, for example, by the bearing shaft  23  being screwed into the severing instrument  1 , preferably into a bearing shaft, not shown in the drawings, of the cutting jaws  2 ,  3 . By releasing this screw connection, the connection of the clamping instrument  18  to the severing instrument  1  can also be thereby released, i.e., it is readily possible to exchange the clamping instrument  18  in a simple way. This clamping instrument can therefore be designed as a disposable part. For example, this clamping instrument could consist of a sterilizable plastic material, which after completion of an operation is detached from the severing instrument  1  and then disposed of. 
         [0037]    Mounted for pivotal movement on one of the two actuating levers of the clamping instrument  18  is a latching bar  29 , which passes through an opening  30  on the other actuating lever  22  and carries saw-tooth-shaped projections  31  on one side thereof. These interact with a corresponding projection, not shown in the drawings, in the opening  30  in such a way that the projections  31  slide along this projection in the opening  30  when the two actuating levers  21 ,  22  are pivoted relative to each other, but that the projections  31  so engage the projection in the opening  30  that an opening of the actuating levers  21 ,  22 , i.e., a pivoting apart, is prevented. To pivot the two actuating levers  21 ,  22  apart, the latching bar  29  must be pivoted by pressure on its free end constructed as a grip surface  32 . The latching bar  29  is then pressed by a spring element  33  with its projections  31  against the projection in the opening  30 . 
         [0038]    This locking device formed by the latching bar  29  thus makes it possible to close the clamping instrument  18 . An opening, on the other hand, is only possible when the user intentionally presses the grip surface  32  of the latching bar  29 . 
         [0039]    The clamping instrument  18  is closed as a consequence of the closing movement of the arms  4 ,  5 , and the parts of the pins  10 ,  11  severed during the closing of the cutting jaws  2 ,  3  are held between the clamping jaws  19 ,  20  which are also closed. When the severing instrument  1  is opened again, the clamping instrument  18  still remains closed owing to the latching bar  29  and continues to hold the cut-off parts of the pins  10 ,  11  firmly, which can then be removed from the operating site together with the severing instrument  1  and the clamping instrument  18  held thereon. The latching bar  29  is usually only released outside of the operating site, so that the severed parts can then be removed. These may, however, also remain in the closed clamping instrument  18 , which is then detached in its entirety from the severing instrument  1  and disposed of. 
         [0040]    The clamping instrument  18  thus ensures that the severed parts of the pins  10 ,  11  cannot get lost in an uncontrolled manner. Moreover, the clamping instrument  18  has the additional advantage that shortly before the severing of the pins  10 ,  11 , these are secured between the clamping jaws  19 ,  20 , so that the pins are prevented from sliding away during the severing procedure. 
         [0041]    In the embodiment of  FIGS. 1 to 5 , the locking device of the actuating levers  21 ,  22  is formed by the latching bar  29 . 
         [0042]    In contrast thereto, in the embodiment according to  FIG. 8 , which is otherwise of similar construction and in which like parts bear like reference numerals, a free pivotability of the two actuating levers  21 ,  22  in the closing direction and a blocking or locking in the opening direction are achieved by the two actuating levers  21 ,  22  respectively carrying on the sides that face each other a latching disc  34 ,  35  which concentrically surrounds the bearing shaft  23 . These two latching discs  34 ,  35  are fitted with saw-tooth-shaped teeth which engage one another, so that the latching discs  34 ,  35  can slide past each other in one direction of rotation, whereas a blocking occurs in the opposite direction of rotation. The two latching discs  34 ,  35  thus form a kind of freewheel by means of which a closed position once reached can also be retained. 
         [0043]    This can only be released for the user by the clamping instrument  18  being completely detached from the severing instrument  1 , for example, by screwing out the bearing shaft  23  by means of a turning knob  36  which is connected to it. 
         [0044]    From the illustration in  FIG. 5  it will be clear that there are arranged in the recesses  16 ,  17 , which are immediately adjacent to the cutting edges  8 ,  9  of the cutting jaws  2 ,  3 , deforming projections  37 ,  38 , which project into the receiving space formed by the recesses  16 ,  17 , and which, upon closing the cutting jaws  2 ,  3 , bend over locking projections  39 ,  40  on the end plate  15 .  FIG. 6  shows these locking projections  39 ,  40  in the undeformed state on one side of the end plate  15 , where they protrude in the plane of the end plate  15  towards opposite sides, whereas  FIG. 7  shows how these locking projections  39 ,  40  are bent at right angles after the cutting procedure and thus lie with their side against a component  41  of the intervertebral implant  12  and thereby lock it against displacement. The locking projections  39 ,  40  are bent over by being made to abut on the deforming projections  37 ,  38  in the recesses  16 ,  17  during closure of the cutting jaws  2 ,  3 , so that the cutting jaws assume a double function in this respect, namely firstly the deformation of the locking projections  39  and  40 , and, secondly, the severing of the pins  10 ,  11 .