Abstract:
The present invention relates to a clamping sleeve for clamping a cannulated drill and a guide wire for medical purposes, wherein the clamping sleeve can be introduced into the chuck of a drilling machine, comprising:
       at least one drill contact area which protrudes into the interior of the clamping sleeve in order to clamp the cannulated drill, through which the guide wire runs, when a force acts inwards on the outer side of the clamping sleeve;   at least one wire contact area in order to clamp an exposed part of the guide wire which is not enveloped by the cannulated drill when the force acts inwards on the outer side of the clamping sleeve;   wherein the at least one wire contact area and the at least one drill contact area lie sequentially in the longitudinal direction of the clamping sleeve.

Description:
RELATED APPLICATION DATA 
     This application claims the priority of U.S. Provisional Application No. 61/104,861, filed on Oct. 13, 2008, which is hereby incorporated in its entirety by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a clamping sleeve for clamping a cannulated drill and a guide wire, in particular a Kirschner wire. The clamping sleeve thus in particular serves medical purposes. The clamping sleeve is intended to simultaneously clamp the cannulated drill and the guide wire, such that the cannulated drill is fixed relative to the guide wire. 
     BACKGROUND OF THE INVENTION 
     In known cannulated drills, the guide wire is guided loosely through the drill. In the known method, the guide wire serves in particular to guide the drill. 
       FIG. 1  schematically shows a fracture  22  or fissure  22  in a bone  20 . The bone fracture  22  is fixed using two Kirschner wires  30  and  32 . In the prior art, another Kirschner wire  10  is then inserted. The position of the inserted Kirschner wire  10  is checked by means of an x-ray apparatus or C-arm. If the check reveals that the position is not correct, the Kirschner wire  10  is removed and re-inserted until the check using the x-ray apparatus reveals an acceptable position of the Kirschner wire  10 . An incorrect position of the Kirschner wire  10  can also result when the Kirschner wire  10  is navigated, since the Kirschner wire  10  can be bent in the bone  20 . “Navigation” here means for example attaching marker elements or a marker array consisting of a number of marker elements to a part of the Kirschner wire or to an object which is fixedly connected to the Kirschner wire. In the case of a wire which is clamped in a chuck, for example, this would be the corresponding drilling machine and a marker array at the target region, for example the fractured bone. The position of the marker elements is detected by a detection device. The marker elements can actively emit beams or waves (for example, infrared beams) or passively reflect beams or waves (for example, infrared beams). The emitted or reflected beams or waves are detected by a detector (for example, an infrared camera). The position of the marker elements can thus be determined from the detection signals. Since the relative position between the marker elements and the part to be navigated (in this case, the tip of the Kirschner wire) is known, the position of the Kirschner wire  10  can be determined, but only providing the Kirschner wire  10  is not bent. 
     Once the position of the Kirschner wire  10  has been approved, a cannulated drill  11  is guided over the Kirschner wire, in order to create a drill hole  40 —indicated in  FIG. 1  by a broken line—on the bone, by means of a drilling machine. Once the drill hole has been completed, the drill is removed and a screw is threaded over the Kirschner wire in order to fix the bone fracture at the envisaged position by means of the screw. The Kirschner wire assists in correctly positioning the screw as the screw is screwed into the drilling channel produced. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to enable the guide wire to be drilled into an object together with the drill during the drilling process. 
     The above object is solved by a clamping sleeve for clamping a cannulated drill and a guide wire for medical purposes, wherein the clamping sleeve can be introduced into the chuck of a drilling machine, comprising: at least one drill contact area which protrudes into the interior of the clamping sleeve in order to clamp the cannulated drill, through which the guide wire runs, when a force acts inwards on the outer side of the clamping sleeve; at least one wire contact area in order to clamp an exposed part of the guide wire which is not enveloped by the cannulated drill when the force acts inwards on the outer side of the clamping sleeve; wherein the at least one wire contact area and the at least one drill contact area lie sequentially in the longitudinal direction of the clamping sleeve, and by a system consisting of the cannulated drill, the guide wire and said clamping sleeve, wherein if the clamping sleeve surrounds the cannulated drill comprising an interior guide wire, both are fixed if a force acts inwards, wherein if there is no force acting inwards, the distance between the wire contact area and the guide wire is different to, i.e. greater or smaller than, the distance between the drill contact area and the cannulated drill, and/or the clear width in the region of the drill contact areas is greater than the diameter of the drill if there is no force acting inwards, and/or the clear width in the region of the wire contact area is greater than the diameter of the guide wire if there is no force acting inwards. The dependent claims are directed to advantageous embodiments. 
     The clamping sleeve in accordance with the invention can advantageously be introduced into the chuck of a drilling machine. It thus lies between the inner surface of the chuck and the outer surface of the cannulated drill and the outer surface of the guide wire which is not enveloped by the cannulated drill. 
     The clamping sleeve preferably comprises at least one drill contact area which serves to fix the cannulated drill when the drill contact area is pressed against the cannulated drill. The drill contact area preferably protrudes into the interior of the clamping sleeve, in particular in the radial direction. The drill contact area relays a force, which acts on the outer side of the clamping sleeve and is in particular exerted by the chuck, onto the cannulated drill, such that in particular a force-fit connection between the cannulated drill and the clamping sleeve results. Alternatively or additionally, recesses or protrusions can be formed in the cannulated drill or in the drill contact area, which interlock in such a way that a positive-fit connection results. 
     The cannulated drill has a drilling tip which is situated at one end (the first end) of the drill. The guide wire protrudes at least from the other end (the second end). The second end of the drill comprises the drill shaft. A tip of the guide wire can in particular protrude from the first end. The drill contact area of the clamping sleeve preferably contacts the drill shaft, while the wire contact area contacts the guide wire which protrudes from the second end of the drill. A part of the drill, in particular the drilling tip, preferably protrudes from one end (the first end) of the clamping sleeve, while the guide wire in particular protrudes from the other end (the second end). The longitudinal direction of the clamping sleeve runs from the first end to the second end of the clamping sleeve. The drill contact area and the wire contact area preferably lie sequentially along this longitudinal direction. The first end is then also referred to as the first longitudinal end. The second end is then also referred to as the second longitudinal end. 
     The wire contact area and/or drill contact area preferably protrude inwards in the radial direction. The at least one wire contact area preferably protrudes further inwards than the at least one drill contact area. The wire contact area thus has a smaller distance from the (virtual) longitudinal axis of the clamping sleeve which runs in the longitudinal direction. 
     The drill contact area and wire contact area are preferably formed such that they enable and ensure a full contact, in particular a positive-fit and/or force-fit contact, with the drill and/or guide wire, in particular when an external force acting inwards is exerted on the clamping sleeve. If the drill shaft is cylindrically formed, then the surface of the drill contact area is preferably likewise cylindrical, i.e. formed as a cylindrical area portion. If the guide wire is cylindrically formed, then the surface of the wire contact area is preferably likewise cylindrically formed, i.e. in the shape of a cylindrical area portion which surrounds the guide wire. A positive-fit connection between the drill and the drill contact area and/or between the guide wire and the wire contact area can also be formed. To this end, protrusions or recesses can for example be formed along the circumference of the drill and/or guide wire, with which matching, in particular complementarily formed extensions or recesses on the clamping sleeve can engage. 
     Preferably, the clamping sleeve is elastically spread, i.e. it dilates in particular in the direction of the first end, wherein this dilation can be reduced or completely eliminated due to the clamping sleeve being elastically formed, in particular when an external force acts. The dilation is in particular shown by the fact that the wire contact area and/or drill contact area is inclined with respect to the longitudinal axis of the clamping sleeve. The inclination is preferably such that surface points on the surface of the wire contact area and/or drill contact area are increasingly distant from the longitudinal axis of the clamping sleeve, in the longitudinal direction of the clamping sleeve in the direction of the first end of the clamping sleeve (which is nearer to the drill tip than the second end of the clamping sleeve). The aforesaid spreading and/or inclination and the associated increasing distance from the longitudinal axis preferably obtains in the state of the clamping sleeve in which there is no force acting on it. The clamping sleeve is preferably formed such that due to the elasticity and/or deformability of the clamping sleeve, the spread state can be corrected by applying an external force, such that the surfaces of the drill contact area and/or wire contact area run parallel to the surfaces of the drill and/or guide wire. In particular, this is intended to result in a parallel profile when the drill contact area and/or wire contact area are completely in contact with the drill and/or wire, respectively. 
     The clamping sleeve is preferably sub-divided into sectors in its longitudinal direction. These sectors are in particular (on average) increasingly distant from the longitudinal axis of the clamping sleeve, from the second end of the clamping sleeve to the first end. At least one sector preferably comprises at least one drill contact area and at least one wire contact area. Preferably, each sector comprises at least one drill contact area and at least one wire contact area. The sectors are preferably connected to each other at one end, preferably the second end, of the clamping sleeve (for example, in a material fit and/or integrally). The sectors are spaced apart from each other over a broad region of the longitudinal extension of the clamping sleeve, in particular separated by a gap, if there is no force acting inwards on the clamping sleeve from without. This longitudinal region of the clamping sleeve for which spacing is provided between the sectors preferably extends over more than 50% of the length of the clamping sleeve, preferably over more than 80% of the length of the clamping sleeve. A spacing is preferably provided at the first end of the clamping sleeve, from where it extends in the direction of the second end. The spacing can in particular be formed as a gap which tapers from the first end to the second end. 
     The spacing of the sectors is preferably formed such that when a force is applied inwards from without, the sectors are moved towards each other until they mutually approach or contact each other. The drill contact area and/or the wire contact area is preferably formed such that when the sectors contact, a parallel surface of the wire contact area and/or drill contact area arises, which is parallel to the longitudinal axis of the clamping sleeve, as viewed in the longitudinal direction of the clamping sleeve. 
     The wire contact area is part of a wire contact portion of the clamping sleeve, which extends (radially) outwards from the wire contact area to the outer area of the clamping sleeve. The drill contact area is part of a drill contact portion of the clamping sleeve, which extends (radially) outwards from the drill contact area to the outer area of the clamping sleeve. The wire contact portion is connected to one end of the clamping sleeve, in particular the second end, by a first connecting portion. The wire contact portion is preferably also connected to the drill contact portion by a second connecting portion. The first connecting portion is preferably formed to be more elastic than the wire contact portion and/or the drill contact portion. The second connecting portion is preferably formed to be more elastic than the wire contact portion and/or the drill contact portion. In particular, the first connecting portion can exhibit a different elasticity to the second connecting portion. The first connecting portion can for example be formed to be more elastic than the second connecting portion. 
     The different elasticity can be realized in various ways. It can for example be realized by different wall thicknesses of the portions or by different materials. The sectors can also be formed with different widths, which can be achieved by expanding the spacing (the gaps in the region of the portions). In other words, the portions are constricted or waisted at the points where they are to be more elastic. 
     In one embodiment, the clamping sleeve can be configured such that, if it is for example inserted in a chuck and a force acting inwards is to be exerted on it via the chuck, the chuck only contacts a part or a region of the clamping sleeve. In particular, the embodiment can be configured such that the chuck only contacts a region of the clamping sleeve which is nearer to one of the two longitudinal ends (the first or second end) of the clamping sleeve than to the other longitudinal end. The region is in particular in the vicinity of the first (i.e. in particular flared) end of the clamping sleeve. The drill contact portion is in particular formed to be protruding with respect to at least one of the following portions: the first connecting portion; the second connecting portion; and the wire contact portion. In this way, the drill contact portion is pressed in the direction of the longitudinal axis by an application of force, while other portions are in particular not in contact with the chuck. In particular, the drill contact portion performs a sort of pivoting movement about an elastic region of the first and/or second connecting portion. Depending on how the elasticity of the first and/or second connecting portion is formed, the circumference of the pivoting movement about the first connecting portion can turn out different to that about the second connecting portion. This can be used to achieve a contact between the drill contact area and the drill and between the wire contact area and the guide wire in a desired sequence, while the chuck pushes ever further inwards, i.e. draws nearer and nearer to the longitudinal axis of the clamping sleeve. 
     As stated above, the clamping sleeve in accordance with the invention is preferably used in a navigated system. In this case, it is advantageous if the position of the drilling tip is known relative to the drilling apparatus (drilling machine). This is for example achieved by a calibrating step by means of a second known navigated object which can indicate the position of the drill tip relative to the marker devices fastened to the Kirschner wire. 
     In order to facilitate use and to validate the length calibration in a navigated application, the sleeve can additionally also comprise a stopper for the chuck, in order to prevent the sleeve from slipping into a chuck which is too large. This stopper protrudes (radially) outwards. As viewed in the longitudinal direction of the clamping sleeve, this chuck stopper is therefore nearer to the drilling tip than the chuck is. 
     In order to further validate the length calibration for navigation, by positioning the drill and in particular the drilling tip in a defined way relative to the clamping sleeve, an abutting area for the end of the drill is preferably provided which is also referred to here as the “drill end abutting area”. This drill end abutting area is preferably part of the clamping sleeve, in particular an integral part, and preferably protrudes into the interior of the clamping sleeve in the direction of the longitudinal axis, in particular radially inwards. It in particular protrudes oblique, transverse or perpendicular to the direction of longitudinal extension of the clamping sleeve. The drill end abutting area can be part of the wire contact portion and can in particular be formed by the part of the wire contact portion which is nearest to the first end of the clamping sleeve. It can in particular be an area of the wire contact portion which faces the first end of the clamping sleeve. 
     The present invention is also directed to a system which, in addition to the clamping sleeve, also preferably comprises the cannulated drill and/or the guide wire. The properties already described above apply to this system, in particular when a force is applied or if there is no force applied. This system is in particular configured such that the distance between the guide wire and the wire contact area and the distance between the drill and the drill contact area are selected such that, as the force applied outwards from within increases, a force-fit contact ultimately arises between the clamping sleeve and both the drill and the guide wire. This can in particular be realized in such a way that the distances between the wire contact area and the guide wire are selected to be different to those between the drill contact area and the drill. Preferably, the distance between the drill contact area and the drill is greater than the distance between the wire contact area and the guide wire, if there is no force being exerted. 
     The inner diameter in the region of the drill contact area is preferably greater than the diameter of the drill, when free of any forces. The inner diameter at the wire contact area is preferably greater than the diameter of the wire, when free of any forces. 
     The system can also comprise a drilling machine, a drilling apparatus or a chuck, to which a marker device is in particular attached. The marker device preferably comprises a number of marker elements, in particular in a defined position relative to each other. The marker elements can actively emit signals, or can reflect signals. The signals are in particular beams or waves, for example infrared beams or ultrasound waves. The signals can be detected by a detection device, in order to determine the position of the marker device. 
     If an independent calibration for the position of the drill tip is not used, a known position of the drilling tip is then revealed solely by the defined position between the marker device and the drilling machine and between the drilling machine and the chuck and between the chuck and the clamping sleeve and between the clamping sleeve and the drilling tip, if the dimensions of all the objects are known, by detecting the marker device. 
     The invention is also directed to the use of the clamping sleeve in accordance with the invention and the system in accordance with the invention, in particular to their use for navigating a drill, in particular the drill tip, in particular relative to an object such as for example an implant or a body structure (bone, for example). The invention is preferably also directed to a navigation system which includes a data processing device and a detection device. The detection device serves to detect the aforesaid marker elements, which can for example be attached to the drilling apparatus and/or to the clamping sleeve. The detection signals are processed by the data processing device, in order to determine the position of the drill, in particular the drill tip, wherein the principles known from image-guided surgery (IGS) are in particular used. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features of the invention are disclosed in the following detailed description. Features of different embodiments can be combined with each other. 
         FIG. 1  shows the approach when placing a guide wire in accordance with the prior art. 
         FIG. 2  shows an approach in accordance with the invention. 
         FIG. 3  shows a system in accordance with the invention, in accordance with a preferred embodiment, which comprises a clamping sleeve in accordance with the invention. 
         FIG. 4  shows a cross-section through the clamping sleeve in accordance with the invention. 
         FIG. 5  shows a three-dimensional view of the clamping sleeve in accordance with the invention. 
         FIG. 6  shows another embodiment of the system in accordance with the invention, which comprises a clamping sleeve in accordance with the invention. 
         FIG. 7  shows an exterior (three-dimensional) view of the clamping sleeve of  FIG. 6 . 
         FIG. 8  shows a cross-sectional view of the clamping sleeve of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 2  shows an approach in accordance with the invention. The bone fracture is preferably fixed in advance using the Kirschner wires  30  and  32 . Instead of a conventional drill, however, a navigated drill comprising a marker device is used, such that the position of the drilling tip relative to the bone is known at any time, i.e. as opposed to the prior art, multiple attempts using a Kirschner wire are not required. The Kirschner wire  10  is guided through the cannulated drill  11 . A tip  16  of the Kirschner wire  10  can protrude from the tip of the drill  11 .  FIG. 2  shows the situation before the drill  11  is inserted into the bone  20  in order to create the drilling channel  40 . 
     Proceeding from the situation shown in  FIG. 2 , the cannulated drill  11  is simultaneously introduced into the bone together with the Kirschner wire  10 . Since the cannulated drill is navigated (for example, according to the principles of image-assisted navigation in IGS surgery (image-guided surgery)), the drill hole  40  can be created in the predetermined position, and the Kirschner wire can in particular be positioned exactly. If the drill is introduced together with the Kirschner wire, then the Kirschner wire can be knocked firmly into the bone before the cannulated drill  11  is withdrawn. 
     Cannulated drills are commonly available to the surgeon. If he navigated them while drilling the drill hole, he could achieve a drill hole at the desired location even without Kirschner wires. However, the cannula in the drill then becomes clogged with bone material, which impedes the drilling process. The guiding assistance of the Kirschner wire when introducing the screw is also missing. 
     If a surgeon inserted the Kirschner wire loosely in the cannulated drill, in order to prevent the above, the Kirschner wire would be pushed away from the drilling tip by the bone material during the drilling process. In accordance with the invention, the Kirschner wire is therefore fixed relative to the cannulated drill.  FIG. 3  shows how this is achieved in accordance with an embodiment in accordance with the invention. 
     A clamping sleeve  1  in accordance with the invention is for example pressed inwards by a force F. The clamping sleeve  1  is formed such that the force F creates at least a force-fit contact between the guide wire  10  and the clamping sleeve  1  and between the cannulated drill  11  and the clamping sleeve  1 . More specifically, two contact areas are provided. A drill contact area  12  contacts the drill  11 , in order to achieve a force-fit connection with the drill  11 . A wire contact area  13  contacts the guide wire  10 , in order to achieve a force-fit connection with the guide wire  10 . The force F is applied by the chuck of a drilling apparatus or drilling machine. To this end, the arrangement shown in  FIG. 3  is inserted into the chuck  52  of the drilling machine  50  or drilling apparatus  50 . The guide wire  10  can in particular run through the drilling apparatus  50 . A marker device  54  comprising marker elements  56 ,  57  and  58  can be attached to the drilling machine  50 . This marker device can be detected using a detection device (not shown) of a navigation system for navigating instruments. By detecting the marker device, it is then possible to navigate the drill and in particular the drilling tip. The chuck  52  abuts a stopper  7 , formed in the manner of a flange, at the first end of the clamping sleeve  1 . This results in a known relative position between the clamping sleeve  1  and the marker device  54 . Furthermore, the drill  11  abuts the drill end abutting area  13 b which is situated to the left of the wire contact area  13  in  FIG. 3 . This results in a known relative position between the clamping sleeve  1  and the drill  11 . Since the distance between the drilling tip at one end of the drill and the other end of the drill  11  is known, the relative position between the drill tip and the marker device  54  is therefore known, such that the drill tip can be navigated by detecting the marker device  54 . In order to register the drilling tip in the reference frame of the navigation system, and in particular in order to determine the position of the drilling tip relative to the marker device, a scanning process is preferably performed in which the position of surface points or regions of the drilling tip and/or drill  11  and/or clamping sleeve  1  are detected. To this end, a calibrating matrix is for example used such as is commonly used when calibrating/validating tools or implants. This calibrating matrix can in particular be used to determine the position of the tip and the shape of the instrument—in this case, the drilling tip and/or drill and/or clamping sleeve. As an alternative to the aforementioned approach, the drill tip can for example be detected by the navigation system using a so-called pointer or any other tool having a known geometry. The pointer or tool comprises at least two markers which, when detected, allow the position of a specific point, for example the pointer tip, to be determined. If the defined point abuts the drilling tip, the position of the drill tip is therefore detected. In particular, it is registered in the reference frame of the navigation system. The position of the drilling tip relative to the marker device  54  is in particular therefore known. 
     As shown in  FIG. 3 , the marker device  54  can be detected by means of a detection device  120 . The detection device  120  is part of a navigation system which in particular comprises a data processing device  100  which processes the detected signals in order to determine the location of the marker arrays or marker devices. The navigation system can in particular determine the location of the drill tip. The monitor  110  can be used to display the location of the drill tip, for example relative to a bone  20  on which a marker device can for example also be arranged. 
       FIG. 4  shows a clamping sleeve  1  in cross-section. The longitudinal axis of the clamping sleeve is shown by a dot-dash line. The clamping sleeve is flared to the left, at an angle α relative to the longitudinal axis. The contact areas  12  and  13  are connected via a stay  2 . The wire contact area  13  is connected to the right-hand end  15  via a stay  3 . The right-hand end  15  faces the drilling apparatus  50 . The stays or connecting portions  2  and  3  can have different lengths and/or different thicknesses and/or can be formed from different materials. In this way, a rigidity or elasticity can arise between the end  15  and the wire contact area  13  which is different from the rigidity or elasticity provided between the wire contact area  13  and the drill contact area  12 . By setting a different elasticity and/or by setting the aperture angle α and/or by the size of the clear widths D 1  and D 2 , it is possible to set the applied external force F at which contact arises between the wire contact area  13  and the guide wire  10  and between the drill contact area  12  and the cannulated drill  11  and/or the extent to which the clamping sleeve has to be pressed together in order to ensure said contact. 
     The connecting portions or stays  2  and  3  are in particular formed to be more elastic than the regions  12   a  and  13   a  which respectively lie radially outwards from the contact areas  12  and  13 . 
     If a force F is then exerted on the clamping sleeve  1  via a chuck, as shown in  FIG. 3 , the end of the clamping sleeve facing the drill side (the left-hand end, see  FIG. 3 ) pivots inwards, such that an angle β (not shown) between the drill contact area and the longitudinal axis of the clamping sleeve is reduced in the direction of longitudinal extension of the clamping sleeve. In the situation shown in  FIG. 4 , without the application of an external force, the angle β is equal to the angle α shown. Thus, the clamping sleeve is preferably elastically formed and allows the sleeve to pivot about the end  15  facing away from the drill (the right-hand end, see  FIG. 3 ), such that the angle β is reduced. The angle α is the angle between the wire contact area and the longitudinal axis, as viewed in the direction of longitudinal extension of the clamping sleeve. As the force F increases, this angle α is initially reduced less than the angle β, as shown in  FIG. 6 . This is due to the fact that the force F also causes a pivoting movement about approximately the middle of the stay  2 . 
     If a force is then applied to the clamping sleeve  1 , this results in the pivoting movement described above, until a right-hand end  12   b  of the drill contact area (i.e. an end facing the drill) comes into contact with the drill and/or until a right-hand end  13   b  of the wire contact area comes into contact with the guide wire. Since the connecting portions  2  and  3  are formed to be more elastic than the portions  12   a  and  13   a , which are assigned to the drill contact area or the wire contact area, respectively, a flexing or pivoting process can be performed about approximately the middle  2   a  and  3   a  of the connecting portions  2  and  3  as the force F is increased, until the drill contact area  12  fully abuts the drill  11  and the wire contact area  13  fully abuts the guide wire  10 . 
       FIG. 5  shows an exterior view of the clamping sleeve in accordance with the invention. The clamping sleeve is sub-divided into various sectors in its longitudinal direction. The sectors are separated by slits  8  which taper in the longitudinal direction. The slits  8  taper to the right, i.e. in the direction of the drill. The individual sectors are connected to each other at the right-hand end  9 . If the sectors are pressed together by the application of an external force, for example by a chuck, such that the slits close, then the exterior shape of the clamping sleeve can preferably become cylindrical. Preferably, the wire contact areas and/or the drill contact areas in particular form closed cylindrical areas along the circumference, when pressed together. 
     A protrusion is situated at the left-hand end of the clamping sleeve facing away from the drill, which protrudes radially outwards and in particular serves as a stopper area  7  for the chuck  52 , more specifically as a stopper area  7  for the end of the chuck  52  which faces away from the drilling apparatus. This is shown in  FIG. 3 . The extension which protrudes radially outwards and forms the stopper area  7  is for example formed in a similar way to a flange. An opening  6  is situated at the other end of the clamping sleeve and is provided in order to guide the guide wire  10  through, as is evident from  FIG. 3 . In  FIG. 5 , an alternative embodiment of the slits is indicated by broken lines, in accordance with which the slits  8  do not taper continuously from left to right but rather comprise cavities  8   a  and  8   b . These cavities  8   a  and  8   b  mean that a sector  1   a  of the clamping sleeve in the region of the connecting portions  2  and  3  becomes narrower in the circumferential direction of the clamping sleeve. While the sector  1   a  has a width a in the circumferential direction outside the connecting portions  2  and  3 , this width is reduced to the width a′ and a″ in the region of the connecting portions  2  and  3  due to the cavities  8   a  and  8   b . This leads to an increased elasticity of the sector portion in the region of the connecting portions  2  and  3 . 
       FIG. 6  shows another embodiment. The connecting portions  2  and  3  are formed differently in  FIG. 6  than in  FIG. 3 . In  FIG. 3 , they are shown to have the same thickness. In  FIG. 6 , the connecting portion  2  is thicker than the connecting portion  3 . This means that the connecting portion  2  is more rigid than the connecting portion  3 . Therefore, when an external force F is applied, kinking occurs first and/or more strongly in a middle region  3   a  of the connecting portion  3 . The middle region  2   a  of the connecting portion  2  kinks less and/or only when the force is further increased. If the distance between the drill contact area  12  and the drill  11  and between the wire contact area  13  and the guide wire  10  is suitably selected, this results in the wire contact area  13  likewise fully abutting the guide wire  10  when the drill contact area  12  fully abuts the drill contact area  12 . Due to the greater elasticity of the region  3   a  as compared to the region  2   a , and since the portion  12   a  assigned to the drill contact area  12  protrudes radially outwards with respect to the portion  13   a  assigned to the wire contact area (and in particular also with respect to the connecting portions  2  and  3 ), the force F acts on this portion  12   a  first. This leads to a pivoting or flexing process about the region  3   a , which is formed to be more deformable or elastic than the portion  2   a . This results in a contact between the left-side end of the portion  12   a  and the cannulated drill  11  first. If further force is applied, the contact area  12  becomes more and more parallel to the direction of longitudinal extension of the drill  11 . This simultaneously means that the wire contact area is lowered further and further, until it finally likewise contacts the guide wire  10 , such that a force-fit connection between the clamping sleeve and the guide wire results. If it is lowered further until a force fit and positive fit exists between the contact area  12  and the cannulated drill  11 , this results in the maximum achievable clamping force on the force-fit and positive-fit connection between the clamping jaw  13  and the wire. 
     The portion  12   a  belonging to the drill contact area protrudes outwards by an edge  12   c . This edge  12   c  is also clearly shown in the exterior view of the clamping sleeve  1  in  FIG. 7 . The clamping sleeve  1  is otherwise designed as shown in  FIG. 5 . 
       FIG. 8  shows again, in an enlargement, the cross-section of the clamping sleeve such as is shown in  FIG. 6 . The clear widths D 1  and D 2 , which are defined by the drill contact area  12  and the wire contact area  13 , respectively, are suitably selected in order to achieve a full contact with the drill or guide wire when a force is applied. 
     Computer program elements of the invention may be embodied in hardware and/or software (including firmware, resident software, micro-code, etc.). The computer program elements of the invention may take the form of a computer program product which may be embodied by a computer-usable or computer-readable storage medium comprising computer-usable or computer-readable program instructions, “code” or a “computer program” embodied in said medium for use by or in connection with the instruction executing system. Within the context of this application, a computer-usable or computer-readable medium may be any medium which can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction executing system, apparatus or device. The computer-usable or computer-readable medium may for example be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, apparatus, device or medium of propagation, such as for example the Internet. The computer-usable or computer-readable medium could even for example be paper or another suitable medium on which the program is printed, since the program could be electronically captured, for example by optically scanning the paper or other suitable medium, and then compiled, interpreted or otherwise processed in a suitable manner. The computer program product and any software and/or hardware described here form the various means for performing the functions of the invention in the example embodiment(s). 
     Although the invention has been shown and described with respect to one or more particular preferred embodiments, it is clear that equivalent amendments or modifications will occur to the person skilled in the art when reading and interpreting the text and enclosed drawing(s) of this specification. In particular with regard to the various functions performed by the elements (components, assemblies, devices, compositions, etc.) described above, the terms used to describe such elements (including any reference to a “means”) are intended, unless expressly indicated otherwise, to correspond to any element which performs the specified function of the element described, i.e. which is functionally equivalent to it, even if it is not structurally equivalent to the disclosed structure which performs the function in the example embodiment(s) illustrated here. Moreover, while a particular feature of the invention may have been described above with respect to only one or some of the embodiments illustrated, such a feature may also be combined with one or more other features of the other embodiments, in any way such as may be desirable or advantageous for any given application of the invention.