Patent Abstract:
A connecting device for a surgical instrument having at least one mobile cutting element which is reciprocally movable relative to a fixed jaw by operation of a resiliently loaded mobile grip wherein the connecting device includes an indexing mechanism which can be moved to a first position to permit mounting or removal of the mobile cutting element and a second position to permit independent mounting or removal of the mobile grip.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a surgical instrument comprising a connecting device which permits, according to defined and independent positions, the rapid assembly and/or dismantling of the mobile cutting element and its actuating grip. 
     The connecting device is intended for surgical instruments comprising cutting elements which slide relative to one another. 
     The connecting device is more particularly applicable to surgical instruments comprising a fixed cutting element and a mobile cutting element which are actuated by the agency of an elastically loaded mobile grip. 
     2. Description of the Related Art 
     The applicant has filed patent applications FR 98/05 689 and FR 98/05 690 in France relating to a surgical instrument and a connecting device. 
     The surgical instrument possesses a main body on which a mobile clamping jaw slides by the agency of an elastically loaded grip. 
     The main body is formed by a fixed grip which is extended by an elongate support forming a fixed clamping jaw. The mobile clamping jaw, which is actuated by means of the elastically loaded grip, slides on the fixed clamping jaw in a longitudinal direction. 
     The fixed and mobile clamping jaws respectively possess, opposite the fixed and mobile grips, cutting means which interact with each other during the longitudinal displacements of the said mobile clamping jaw to make successive cuts in the hard bone tissue or soft tissue of a patient. 
     The connecting device in patent applications FR 98/05 689 and FR 98/05 690 merely permit the rapid assembly and dismantling of the mobile element without parts of the,instrument having to be withdrawn. The connecting device comprises means for the angular indexing of the,mobile grip about its axis of rotation to permit, in a given position, the positioning or withdrawal of the mobile element of the main body of the instrument. 
     SUMMARY OF THE INVENTION 
     The purpose of the connecting device according to the present invention is to improve that described in patent applications FR 98/05 689 and FR 98/05 690 in the name of the applicant so as to enable, in predefined and independent positions, both the assembly or dismantling of the mobile element and the assembly or dismantling of the mobile grip. 
     The connecting device for a surgical instrument according to the present invention comprises indexing means defining a first series of angular positions permitting the positioning or withdrawal of the mobile element and a second series of angular positions, independent of the first, for the assembly or dismantling of the mobile grip. 
     The connecting device according to the present invention possesses angular indexing means which are formed by: 
     an elastically loaded pivot for the pivoting of the mobile grip relative to the fixed grip of the main body of the instrument, 
     and guide means solidly fixed to the said mobile grip and interacting with the said pivot and a drive spindle provided on the mobile element for its longitudinal movements relative to the main body. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The description which follows, having regard to the attached drawings, which are given by way of non-limiting examples, will provide a better understanding of the invention, the features which it possesses and the advantages which it is capable of providing: 
     FIG. 1 is a view showing a surgical instrument according to the present invention. 
     FIGS. 2 to  6  are views show the main body of the surgical instrument in detail. 
     FIGS. 7 to  14  are views showing, in detail, the mobile element sliding on the main body of the surgical instrument. 
     FIG. 15 is a view showing the mobile grip of the surgical instrument. 
     FIGS. 16 to  18  are views showing the pivot of the mobile grip on the main body of the surgical instrument. 
     FIG. 19 is a view showing the position of the pivot when the surgical instrument is in operation. 
     FIG. 20 is a view showing the position of the pivot for the positioning or withdrawal either of the mobile grip or of the mobile cutting element. 
     FIGS. 21 a  and  22   a  are views showing the extreme positions of the mobile grip on the main body for the positioning or withdrawal of the mobile cutting element when the pivot is in the position according to FIG.  20 . 
     FIGS. 21 b  to  21   d  and  22   b  to  22   d  are views illustrating the positions of the mobile grip and of the pin of the mobile cutting element in operation when the pivot is in the position according to FIG.  19 . 
     FIGS. 21 e  and  22   e  are views showing the extreme positions of the mobile grip on the main body during its positioning or withdrawal when the pivot is in the position according to FIG.  20   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a surgical instrument  1  of the Kerrison forceps type, comprising a connecting device  100  which permits, in accordance with defined and independent angular positions, the rapid assembly and/or dismantling of a mobile cutting element  8  and of its actuating grip  5 . 
     The surgical instrument  1  comprises a main body  2  formed by a fixed grip  3  which is extended in a substantially horizontal plane by a fixed element or an elongate support  4  constituting a fixed clamping jaw. 
     The main body  2  comprises, at the junction between the fixed grip  3  and the fixed clamping jaw  4 , a mobile grip  5  which pivots about an elastically loaded pivot  6 . 
     The mobile grip  5  is connected to the fixed grip  3  by spring plates  7  which are provided between the two grips to restore the mobile grip  5  to its original position after each pivoting movement. 
     The fixed clamping jaw  4  of the main body  2  interacts with a mobile element or a mobile clamping jaw  8  which slides in a longitudinal direction from front to rear on the said fixed clamping jaw  4  when a force is applied to the mobile grip  5 . 
     The connecting device  100  comprises angular indexing means which make it possible to set the mobile grip  5  in defined and independent angular positions for the positioning or withdrawal of the mobile element  8  of the main body  2 , on the one hand, and the assembly or dismantling of the mobile grip  5  of the said body, on the other hand. 
     FIGS. 2 to  6  show the main body  2  which possesses, within its thickness and at the point of the junction between the grip  3  and the clamping jaw  4 , an aperture of conical profile  9  delimited by opposite and inclined surfaces  10 ,  11  in order that the more open side of the said aperture faces towards the upper edge  12  of the fixed clamping jaw  4 . 
     The main body  2  comprises, on each side of the aperture  9 , an arcuate lug  13  which is pierced by a drilled hole  14  intended to receive the pivot  6  to guide the mobile grip  5  in rotation. 
     The maximum travel of the mobile grip  5  about the pivot  6  within the aperture  9  of the main body  2  is delimited by the inclined and opposite surfaces  10 ,  11 , as will be more clearly seen in due course. 
     The fixed clamping jaw  4  possesses, towards its free end which is opposite to the end through which the aperture  9  passes, a tip  15  extending in a substantially vertical direction, either upwards or downwards relative to the longitudinal axis of the surgical instrument  1 . 
     The tip  15  possesses, within its thickness, a hollow  16  delimiting opposite edges  17  which are inclined relative to the upper edge  12  of the fixed clamping jaw  4 . The edges  17  of the tip  15  are machined to form cutting elements in order to cut bony fragments or soft tissue (FIG.  5 ). 
     The opposite edges  17  of the tip  15  are chamfered outwards at an angle α of approximately 30 degrees relative to the outer edge of the said tip (FIG.  6 ). 
     The fixed clamping jaw  4  is solidly fixed, at its upper edge  12  and opposite the tip  15 , to a T-shaped peg  18  allowing the longitudinal guiding of the mobile clamping jaw  8 . 
     Likewise, the fixed clamping jaw  4  comprises, in the vicinity of the tip  15 , another T-shaped peg  19  which improves the guiding of the mobile clamping jaw  8  over the entirety of its travel (FIGS. 3,  4 ). 
     Moreover, the T-shaped peg  19  possesses, towards the peg  18 , a portion  19   a  of a lesser height than that envisaged for the peg  19 . 
     FIGS. 7 to  14  show the element, or mobile clamping jaw  8 , which comprises, at one of its ends and within its thickness, an arcuate recess  20 . Through this recess passes a drive spindle  21  which interacts with the mobile grip  5  to convert the rotary movements of the said grip into linear movement in order for the mobile clamping jaw  8  to slide on the fixed clamping jaw  4 . 
     The recess  20  communicates with a groove  22  which extends towards the other end of the mobile clamping jaw  8 . The groove  22  possesses, immediately in the extension of the recess  20 , opposite ribs  23  separated by an aperture  24  to form a slide which interacts with the T-shaped peg  18  of the fixed clamping jaw  4  (FIGS. 8,  9 ). 
     The opposite ribs  23  extend into a portion of the groove  22  to form a zone within which the peg  18  is not guided, to permit, in accordance with a defined angular position, the positioning or withdrawal of the mobile clamping jaw  8 . 
     The latter comprises in its inner portion a channel  25  opening opposite to the recess  20  at the position of an inclined end formed by inclined edges  26  which are machined to possess a cutting profile (FIGS. 10,  11 ). 
     The opposite edges  26  of the inclined end of the mobile clamping jaw  8  are chamfered outwards at an angle β of approximately 30 degrees relative to the outer edge of the said clamping jaw (FIGS. 13,  14 ). 
     Furthermore, the upper portions of the opposite edges  26  of the mobile clamping jaw  8  are chamfered towards the interior of the channel  25  at an angle χ of approximately 30 degrees relative to the upper edge of the said clamping jaw. 
     The channel  25  extends towards the recess  20  to open outwards and into the upper portion of the mobile clamping jaw  8  via an oblong opening  27 . 
     It will be noted that the channel  25  is designed to form a magazine making it possible to retain the bone fragments cut away by means of the chamfered edges  17  and  26  of each clamping jaw, both fixed  4  and mobile  8 . 
     The channel  25  possesses, in the vicinity of the inclined edges  26  and at the position of the lower edge  28  of the mobile clamping jaw  8 , opposite ribs  29  separated by an aperture  30  so as to constitute a slide which interacts with the T-shaped peg  19  of the fixed clamping jaw  4  (FIG.  11 ). 
     It will be noted that the channel  25  of the mobile clamping jaw  8  possesses a U-shaped profile which is open towards the lower edge  28 . 
     FIG. 15 shows in detail the mobile grip  5 , which possesses an angled section formed by a short first branch  31  extended by a longer second branch  46 . 
     The first branch  31  is extended, opposite to the second branch  46 , by a plate  32  pierced by a drilled hole  33  communicating with an oblong and open-ended aperture  34 . 
     The drilled hole  33  is designed with a diameter slightly greater than that envisaged for the oblong aperture  34 . 
     The drilled hole  33  is designed to accommodate the pivot  6  in order that the grip  5  may pivot about the latter when it is mounted on the main body  2  of the instrument  1 . 
     The oblong aperture  34  made in the plate  32  of the grip  5  is designed to receive the drive pin  21  passing through the recess  20  of the mobile clamping jaw  8 . 
     FIGS. 16 to  20  show in detail the various elements forming the pivot  6  allowing the pivoting of the mobile grip  5  relative to the main body  2 . 
     The pivot  6  is formed by a screw  35  having a tightening head  36  solidly fixed to a cylindrical body  37  whose end opposite the said head possesses a threaded portion  38 . 
     A compression spring  39  is arranged around the cylindrical body  37  so as to bear against the tightening head  36  and the main body  2  of the surgical instrument  1 , in the assembled position. 
     The cylindrical body of the screw  35  possesses a diameter slightly smaller than that envisaged for the drilled hole  33 , but greater than that of the oblong aperture  34 . 
     The cylindrical body  37  possesses, on each side of its longitudinal axis and from the head  36  towards the threaded portion  38 , a flattened portion  47  reducing in diameter or width over a part of its length. 
     The latter, contained between the diametrically opposed flattened portions  47 , is of a slightly smaller size than the oblong aperture  34  of the plate  32 . 
     The pivot  6  comprises a tightening nut  40  which interacts with the threaded portion  38  of the screw  35 . 
     The tightening nut  40  possesses, on its periphery, an indexing finger  41  which extends towards the head  36  of the screw  35  when the said nut is screwed onto the said screw. The indexing finger  41  is disposed in a plane parallel to that containing the pivot  6  of the mobile grip  5 . 
     The indexing finger  41  comprises an elongate portion  42  possessing two straight and parallel opposite faces  43 ,  44 . 
     Opposite the indexing finger  41 , the tightening nut  40  comprises an open-ended hole  48  which interacts with a finger  49 , extending parallel to the axis of the drilled holes  14  and solidly fixed to the main body  2  for the translatory guidance of the pivot  6  (FIGS.  19  and  20 ). 
     The assembly of the instrument  1  comprises screwing the pivot  6  onto the main body  2  in a manner such that its tightening screw  35  provided with the spring  39  is introduced into the drilled hole  14  of the first lug  13  and then passes through the other drilled hole  14  of the second lug  13  to allow the nut  40  to be screwed onto the threaded portion  38  of the cylindrical body  37 . 
     The assembly of the mobile grip  5  between the two lugs  13  of the main body  2  takes place when the spring  39  of the pivot  6  is compressed to present the flattened portions  47  within the aperture  9  (FIG.  20 ). 
     Specifically, in this position, the nut  40  is moved away from the main body allowing the plate  32  of the grip  5  to be presented in an inclined position and bearing against the surface  11  of the aperture  9  (FIGS. 21 e ;  22   e ). 
     It will be noted that the flattened portions  47  f the pivot  6  interact with the aperture  34  of the late  32  until the said pivot is accommodated in the drilled hole  33 . 
     Locking of the grip  5  on the main body  2  is achieved when the pressure on the pivot  6  is withdrawn. 
     The transverse movement of the pivot  6  under the force of the spring  39  enables the flattened portions  47  of the screw  35  to be positioned outside the drilled hole  33  to prevent any communication with the aperture  34 , as a result of the difference in diameter between the latter and the screw  35  (FIG.  19 ). 
     The positioning of the grip  5  on the main body  2  enables the plate  32  to pass through the aperture  9  and to emerge above the upper edge  12  of the fixed clamping jaw  4  in order to present the oblong aperture  34  for the assembly of the mobile element  8 . 
     The positioning of the mobile clamping jaw  8  on the fixed clamping jaw  4  can only be achieved when the plate  32  of the mobile grip  5  is in the immediate vicinity of the inclined surface  10  of the aperture  9  of the main body  2  (FIGS. 21 a ,  22   a ). 
     For this purpose, it is therefore necessary to exert further pressure to the head  36  of the screw  35  of the pivot  6  in order to compress the spring  39  and release the elongate portion  42  of the indexing finger  41  of the nut  40  (FIG.  20 ). 
     As soon as the portion  42  is withdrawn from its original position, the mobile grip  5 , under the force of the elastic means  7 , can pivot through a few additional degrees about its pivot  6  in order for the indexing finger  41  to bear against the branch  31  and the shoulder SO. 
     In this position, the plate  32  of the grip  5  is placed in the immediate vicinity of the inclined surface  10  in order for the aperture  34  to be directed towards the rear of the main body  2  so as to free its access. The position of the plate  32  allows the introduction of the drive spindle  21  passing through the recess  20  of the mobile clamping jaw  8  in the oblong aperture  34 . 
     It will be found that, in this position, the flattened portions  47  of the pivot  6  are not disposed parallel to the edges of the aperture  34 , thus preventing any possibility of withdrawal of the mobile grip  5 . 
     Simultaneously with the positioning of the spindle  21  in the aperture  34 , the T-shaped peg  18  of the fixed clamping jaw  4  is accommodated in the groove portion  22  furthest from the recess  20  of the mobile clamping jaw  8 , while the peg  19  interacts with the channel  25  provided towards the inclined end of the said mobile clamping jaw. 
     It is then sufficient to press lightly on the mobile grip  5 , compressing the elastic restoring means  7 , for it to pivot about the pivot  6 , thus permitting the indexing finger  41  to be restored to its original position under the action of the spring  39 . 
     In operation, the mobile grip  5 , solidly fixed to the plate  32 , allows the displacement of the mobile clamping jaw  8  on the fixed clamping jaw  4  between an open position, where the chamfered edges  17  and  26  are moved apart from one another, and a closed position, where the chamfered edges  17  and  26  bear against one another (FIGS. 21 b ,  21   c ,  21   d ;  22   b ,  22   c ,  22   d ). 
     Specifically, the angular range of movement of the mobile grip  5  within the aperture  9  of the main body  2  is limited by the indexing finger  41  of the pivot  6  to allow the translatory movement of the mobile clamping jaw  8  on the fixed clamping jaw  4  in accordance with defined longitudinal movements. 
     It will be noted that the grip  5  is automatically restored to its position of rest, in other words when the clamping jaws  4  and  8  are opened by the agency of the elastic restoring means  7  provided between the said mobile grip  5  and the fixed grip  3  of the main body  2 . 
     The transition from the open position to the closed position of the clamping jaws  4  and  8  enables the surgeon to cut fragments of bone or soft tissue by means of the chamfered edges  17 ,  26 . 
     The pieces cut away during the successive movements of the mobile clamping jaw  8  on the fixed jaw  4  are recovered in the channel  25  to prevent their falling amid the operating area. 
     The profile of the peg  19 , possessing a portion  19   a  of lesser height, makes it possible to prevent the build-up within the channel  25  of pieces of tissue cut away by the chamfered edges  17 ,  26 . 
     When the channel  25  is filled with fragments of bone or soft tissue, it is possible to extract them through the oblong opening  26  made in the upper part of the mobile clamping jaw  8 . 
     The connecting device  100  allows the mobile clamping jaw  8  to be withdrawn from the main body  2 , independently of the mobile grip  5 , for the recovery of the fragments of bone or soft tissue, following a procedure reversing that described above for its positioning. 
     Specifically, it is sufficient to apply pressure to the head  36  of the screw  35  of the pivot  6  in order to compress the spring  39  and release the elongate portion  42  of the indexing finger  41  of the nut  40  from its original position between the branch  31  and the shoulder  50  (FIG.  20 ). 
     As soon as the portion  42  is withdrawn from its original position, the mobile grip  5 , under the force of the elastic means  7 , can pivot through a few additional degrees about its pivot  6  in order for the indexing finger  41  to bear against the branch  31  and the shoulder  50 . 
     In this position, the plate  32  of the grip  5  is placed in the immediate vicinity of the inclined surface  10  in order for the aperture  34  to be directed towards the rear of the main body  2  so as to free its access. 
     The position of the plate  32  allows the withdrawal of the spindle  21  from the oblong aperture  34 , and the simultaneous release of the ribs  23  and  29  from the plugs  18  and  19  for withdrawal of the mobile clamping jaw  8  of the main body  2  (FIGS. 21 a ,  22   a ). 
     The mobile grip  5  may likewise be dismantled when it is necessary to carry out complete sterilization of the surgical instrument  1 . 
     For this purpose, it is necessary to unlock the elastic means  7  in order to release the mobile grip  5  from the fixed grip  3  of the main body  2 . 
     Subsequently, it is sufficient to exert pressure on the head  36  of the screw  35  of the pivot  6  in order to compress the spring  39  and release the elongate portion  42  of the indexing finger  41  of the nut  40  from its original position between the branch  31  and the shoulder  50  (FIG.  20 ). 
     In this position, the plate  32  of the mobile grip  5  is positioned in the immediate vicinity of the inclined surface  11  of the aperture  9 , while the flattened portions  47  of the screw  35  are disposed parallel to the edges of the oblong aperture  34  in order for the pivot  6  to be able to slide within the latter for the purpose of withdrawal of the grip  5  (FIGS. 21 e ,  22   e ). 
     FIGS. 22 a  to  22   e  show an alternative embodiment of the profile of the oblong aperture  34  of the plate  32  when the surgical instrument  1  possesses no peg  18  on the main element  2  for the guiding of the mobile element  8 . 
     It will be noted that the oblong aperture  34  possesses, opposite the drilled hole  33 , and in accordance with its longitudinal axis, an oblong seating  51  which possesses a greater width than that envisaged for the said aperture. 
     Likewise, the drive spindle  21  disposed inside the recess  20  of the mobile element possesses diametrically opposed flattened portions  52  which define a spindle size which is substantially smaller than the width of the oblong aperture  34 . 
     By contrast, the diameter of the drive spindle  21  is greater than the width of the aperture  34  to prevent its extraction in the operating position of the surgical instrument, as explained previously (FIGS. 22 b  to  22   d ). 
     The positioning or withdrawal of the mobile element  8  takes place in the same manner as described above, specifically in that the plate  32  must again be in the vicinity of the inclined surface  10  to allow the introduction of the drive spindle  21  in order that its flattened portions  52  are disposed parallel to the opposite edges of the oblong seating  51 . 
     In the operating position, it will be found that the drive spindle  21  retained in the seating  52  constitutes a means for guiding the mobile element  8 , preventing its withdrawal under the compressive forces necessary to cut away fragments of bone or soft tissue between the inclined and chamfered edges  17 ,  26 . 
     It will be noted that the connecting device  100  according to the present invention may be provided on other surgical instruments to permit, in a given position, the positioning or the withdrawal of the mobile element  8  and of the mobile grip  5  of the said instrument.

Technology Classification (CPC): 0