DE10013331A1 - Surgical holder for body joint has clamping elements, pressure element, drive mechanism and three-sided space. - Google Patents

Abstract

The holder (1) consists of two clamping elements (3,4) and a pressure element (11.5) positioned so as to enclose on three sides a space (100) between them and joined by a drive mechanism (7-10,14-17). Each clamping element is linked to a drive lever . The drive mechanism comprises a pressure-drive for the pressure element. The clamping elements are moved so as to reduce their relative distance apart towards the space between and to the pressure element.

Description

The invention relates to a surgical treatment of a joint or a joint prosthesis, especially when implanting a knee joint prosthesis, usable holding device according to the preamble of claim 1.

From the German patent application DE-OS 197 00 474 A1 is a pair of pliers known surgical instrument with which a fixation element for holding can be tensioned by bone elements. There are two of them as industries designated pivot arms are provided which are mounted on a base body. For tensioning the fixing element is by swiveling the branches Working member moved relative to the base body.  

The working member has two clamping jaws that can be placed on the fixing element, which can be subjected to an axial pulling force when swiveling the branches are. The fixing element consists of two relatively small fixing plates, which are moved against each other by the axial pulling force and thereby individual Can hold bone elements.

However, such an instrument cannot disadvantageously be used by the surgeon treatment of a joint or a prosthetic joint, in particular knee steering prosthesis, because fixation elements are required here, which - in relation to the longitudinal axis of the instrument - are essentially radial Can generate directional holding forces. To ensure adequate Fixation between the holding device and the outside of the prosthesis must the holding forces must also be directed towards each other.

It is a further disadvantage of the known surgical instrument that the intended holding elements are small in area and thereby a relatively high effort is required to fix the desired to achieve appropriate elements.

Based on the shortcomings of the prior art, the invention therefore lies the task is based on a holding device of the type mentioned specify with which with relatively little effort in a simple manner force components directed against one another and / or transversely to one another can be. The force components should be essentially the same size in order a secure, external bracing of the holding device on a joint or on a joint prosthesis, especially a knee joint prosthesis.

The object is achieved by a holding device, the characteristics of which are known in drawing part of claim 1 are described.

The invention includes the finding that with a parallelogram  Linkage at the corner points of this parallelogram directed towards each other, in generated essentially equal forces and transferred from these key points can be, if these points by external force on the Parallelogram can be moved in the same way. Such forces can be caused by the in a parallelogram leverage advantageously in relative small amount of force from the outside in the required to fix objects Chen size are generated.

According to the preferred embodiment of the invention, the holding device Direction for fixing of necessary during surgical treatment at least parts of a joint or joint prosthesis, especially one Knee joint or a knee prosthesis, a guide device and with arranged on the guide device. There are at least two clamping elements, a pressure element and one with the clamping elements Drive device connecting the guide device is provided and such arranged to each other that they have a space between them from three sides include and are connected to each other via the drive device in such a way that a movement of the pressure element in the direction of the space with a Movement of the clamping elements in the direction of this space for generation a clamping force acting on an object located in the intermediate space goes.

The drive device comprises a lever drive such that each clamping element is articulated with at least one drive lever. The drive lever has a connection with a pressure drive for the printing element fiction according to such that the clamping element in the direction of the space moved, by the pressure drive a force component on the Druckele is generated in the direction of the gap. At the same time, the relative lateral distance of the clamping elements, if this is due to the lever drive at the same time in the direction of the joint or Joint or prosthesis part are moved.  

To fix one between the ends of the clamping elements for receiving the the space required to secure the joint or joint prosthesis parts strut-shaped drive levers spaced apart from one another are provided. These struts are on the one hand with the pressure drive carrying the pressure element, which on the joint or joint to be treated surgically End of the guide device facing the prosthesis is arranged, and on the other hand articulated with the clamping element. Two drive levers, one The section of the pressure drive and a clamping element each form the sides parts of an essentially parallelogram or trapezoidal four-bar linkage, which with its side formed by the pressure drive on the guide direction is attached.

According to the preferred embodiment of the invention there are two clamps elements each as a side of one of the parallelogram-shaped four-joint hen. The two four-bar joints are mirror-symmetrical to one another on the guide facility arranged. This can be done in these parallelogram-shaped four-bar joints respective clamping element when force is exerted on one of the parallelogram corner points te on which the drive levers are articulated to the clamping element, make a movement parallel to the central body. To create this The lever drive provided on the guide device acts on the force, which according to the preferred embodiment of the invention is rotatable mounted, threaded drive spindle and one on the drive Has axially movable sliding piece. To transmit the movement of the sliding piece on the respective parallelogram-shaped four-bar linkage are two Push rods provided. The connection between the push rod and the Sliding piece or the Paral formed by the drive lever and clamping element The lelogram corner point is articulated.

The push rods are arranged symmetrically to the drive spindle and point in essentially the same length, so a similar and to the drive spindle mirror symmetrical movement of the holding elements to each other  can to the desired force effect for fixing a joint or a To produce joint or prosthesis part.

According to an advantageous variant of the invention it is provided that the thrust extend in parallel planes.

According to another advantageous embodiment of the invention, the Holding device a drive device with only one pressure drive, in which arranged a rack axially displaceable by the drive spindle is net, in which the ends of the holding elements are connected to the central body intervening struts. This Eden the articulated in the central body Holding elements are equally provided with a toothing, which to the force Transfer from the pressure drive to the holding elements in the rack intervenes. On the one hand, this simplifies the design in a favorable manner Structure of the holding device, since the push rods for power transmission are no longer are necessary, on the other hand, the change can be made by direct intervention the toothing very simply the gear ratio of the individual movements adapt to the respective requirements.

For positioning the holding device on the joint or joint prosthesis part the holding device with one end of its pressure drive on the joint or Articulated prosthesis part with simultaneous thrust movement. Because of the Rack coupling results in a lateral clamp movement of the clamp elements in the direction of the joint or joint prosthesis part. By a turn the drive spindle of the drive device can be with the joint or Articulated prosthesis part axially in contact with the end of the pressure drive be moved. Thus, the holding device is easily by three Force components can be fixed firmly to the joint or joint prosthesis part.

According to a favorable variant of the invention, the rack and in the The ends of the struts on the central body have a trapezoidal serration, since here  the uniformity of the relative movement of the two holding elements is particularly simple is to be secured.

According to a further advantageous variant of the invention, the clamp elements formed as a substantially claw-shaped jaws to cheap Conditions for the introduction of force into the joint or joint to be fixed to create prosthetic parts.

In the preferred embodiment of the invention is for actuating the drive despindel the drive provided a handwheel. Depending on the diameter the handwheel can change the amount of force that is required is the desired holding force when fixing a joint or joint to produce prosthetic part.

According to another advantageous development of the invention, the print former carries on its joint facing the joint or joint or prosthesis part to be fixed Side a pressure element designed as a stop, with which the Haltvor Direction on the part to be fixed if the clamping elements by the Lever drive can be moved. This stop is particularly convenient Manageability of the holding device favorable if this during an operati ven intervention must be positioned in the corresponding joint area.

In an advantageous variant of the holding device according to the invention is between rule central body and sliding piece a spring element arranged to on a fold the sliding back of the sliding piece while relaxing the Haltvor to facilitate direction.

Other advantageous developments of the invention are in the subclaims are identified or described below together with the description of the preferred embodiment of the invention with reference to the figures.  

Show it:

Fig. 1 shows a preferred embodiment of the invention in perspektivi shear representation,

FIGS. 2a and 2b, the embodiment shown in Fig. 1 of the invention in top view and in side view,

FIGS. 3a and 3b, the embodiment of the invention in the open state shown in Figs. 1, 2a and 2b and

FIGS. 4a and 4b, another advantageous embodiment of the invention in to view from above and in side view.

The retaining device 1 shown in Figs. 1, 2a, 2b, 3a and 3b for fixing of at least parts of a knee joint or a knee joint prosthesis at a surgical treatment has a guide device 2 and two at the Füh inference means arranged clamping jaws 3, 4 which are movable by a lever drive 16 , 17 . In order to secure between the ends 3.1 and 4.1 of the clamping jaws 3 , 4 a space 100 required for receiving the joint or joint prosthesis parts to be secured, spaced-apart, strut-shaped guide levers 7 , 8 , 9 , 10 are provided. The struts 7 , 8 , 9 , 10 are on the one hand with a central body 11 of the pressure drive, which is arranged on a surgically treated joint or joint or prosthesis part 101 towards the end of the guide device 2 - displaceable ver by the drive spindle 14 , and on the other hand, each connected to a clamping jaw 3 or 4 by means of a joint 7.1 , 8.1 or 9.1 , 10.1 and 11.1 , 11.2 , 11.3 and 11.4 .

Two struts 7 , 8 or 9 , 10 , the central body 11 of the pressure drive and a clamping jaw 3 or 4 each form the side parts of an essentially parallelogram-shaped four-bar linkage 12 or 13 , which with its side formed by the central body 11 on the guide device 2 is attached. The two parallelograms 12 , 13 are arranged mirror-symmetrically to one another on the guide device.

In these four-bar joints 12 , 13 , the respective clamping jaw 3 , 4, when force is exerted on one of the four-bar corner points 12.1 or 13.1 , at which the strut 7 and 9 are articulated to the clamping jaw 3 or 4 , one parallel to that in wesentli chen Execute central body 11 directional movement, the relative distance between the jaws is simultaneously reduced. This creates a clamping force by means of which the prosthesis part 101 located in the free space 100 is fixed. The lever drive 16 , 17 , which is connected to a sliding piece 15 , is used to generate this force. The sliding piece 15 is guided axially displaceably along the guide device 2 . In addition, the sliding piece 15 includes a threaded spindle 14 rotatably mounted in the guide device 2 . To transmit the movement of the sliding piece 15 to the parallelo-shaped four joints 12 , 13 , a push rod 16 , 17 is hen vorgese.

The sliding piece 15 can also be arranged freely movable with respect to the threaded spindle 14 , so that the clamping jaws 3 and 4 are moved towards one another by pushing the sliding piece 15 in the direction of the central body 11 .

In a preferred embodiment variant, the sliding piece 15 and threaded spindle 14 are in engagement with one another in such a way that the sliding piece is axially displaced by rotating the threaded spindle 14 . The threaded spin del 14 is axially immovable in the central body 11 . Due to the spindle drive, larger forces can be introduced into the lever parallelogram 7 , 8 , 9 , 10 , 3 and 4 via the sliding piece 15 and the push rods acting as the drive levers 16 and 17 , so that the clamping jaws 3 and 4 can exert large clamping forces.

In a likewise preferred embodiment variant, the sliding element 15 and the threaded spindle 14 are connected to one another in such a way that the threaded spindle 14 can rotate freely in the sliding piece 15 , but the sliding piece is non-displaceable in the direction of the longitudinal axis of the threaded spindle 14 . In this variant exporting approximately engages the thread of the threaded spindle 14 in such a way in the Zentralkör by a 11 that that the threaded despindel shifts axially during rotation of the threaded spindle 14 with respect to the fourteenth At the same time, the central body 11 is guided axially displaceably by the guide device 2 . By the central body is axially displaced by rotating the threaded or drive spindle 14, a stop is 11.5 of the central body 11 of the moved with respect to the end of the threaded spindle 14 in the direction of joint or joint or prosthesis part 101 to be treated, while the clamping jaws 3 and 4 to be moved laterally towards the joint or joint or prosthesis part 101 to be treated. Thus, when the clamping force is generated by the clamping jaws, a compressive force directed transversely to the clamping force generated by the clamping jaws is simultaneously introduced into the prosthesis part, so that the prosthesis part 101 is clamped on three sides.

In this way, by coupling the lever drive 16 , 17 for the clamping jaws 3 , 4 with the pressure drive 11 , 14, a drive device is realized in which the relative lateral spacing of the clamping jaws 3 , 4 is reduced when the lever drive in the direction of the treating joint or joint or prosthesis part 101 are moved and at the same time a movement of the central body 11 of the pressure drive takes place in the same direction.

The spindle 14 carries a stop 11.5 as a pressure element on its side facing the knee joint or prosthesis part to be fixed, with which the holding device 1 is supported on the knee joint part 101 to be fixed when the clamping jaws 3 , 4 by the drive 14 , 15 can be moved. The stop 11.5 is pivotally attached to the end of the spindle 14 by means of a ball joint. The stop 11.5 is also favorable for easy handling of the holding device 1 , since it can be positioned in the corresponding joint area without special effort during an operation.

When the spindle 14 is axially immovable in the central body 11 , the stop 11.5 can also be pivotally attached to the central body 11 by means of a ball joint.

The connection between the push rod 16 or 17 and the sliding piece 15 is designed as a joint 18.1 or 18.2 . The other end of the push rods 16 , 17 forms part of the articulated connection 7.1 or 9.1 between the parallelogram corner point 12.1 , 13.1 formed by a strut 7 , 9 and the clamping jaw 3 , 4 .

The push rods 16 , 17 extending in mutually parallel planes are arranged symmetrically to the threaded spindle 14 and have essentially the same length, so that a similar and mirror-symmetrical movement of the clamping jaws 3 , 4 to the threaded spindle 14 can take place in order to achieve the desired one To generate force to fix the knee joint or prosthesis part 101 . For further synchronization of the movement of the guide levers or struts 7 and 9 or 8 and 10 , these can be gear-like at their inner ends and arranged in relation to one another such that the gear-like ends of the mutually associated struts 7 and 9 or 8 and 10 mesh with one another .

The arranged between the central body 11 and the sliding piece 15 straight coil spring 15.1 supports in a simple manner the sliding back of the slide assembly 15 when the clamping jaws 3 , 4 have to be returned to their starting position when the holding device 1 is relaxed.

A handwheel 19 , which is screwed to the end of the threaded spindle 14 facing away from the central body by 11 of the pressure drive, serves to actuate the drives.

In FIGS. 4a and 4b, a holding device 20 with a Führungseinrich tung and 21 to a pressure drive, which is a stationary disposed Zentralkör per 22 has, shown in the open state. A toothed rack 24 which is axially displaceable by a threaded spindle 23 is arranged in the central body. The ends of the struts 25 , 26 and 27 , 28 engage in this toothed rack 24 and connect the claw-shaped clamping jaws 29 and 30 to the central body 22 . These ends of the struts 25 , 26 and 27 , 28 which are mounted in the central body 22 in joints 31 , 32 and 33 , 34 are equally provided with a toothing 35 which engages in the toothing of the toothed rack 24 to transmit force to the clamping jaws.

The pressure drive of the holding device 20 consists of the threaded spindle 23 and the toothed rack 24 axially displaceable on it within the central body 22 . If the holding device 20 is placed on the prosthesis part using the guide device 21 with the stop 22.1 while simultaneously applying axial pressure, the clamping jaws 29 , 30 move in the direction of the prosthesis part and press against one another from the side. By slightly turning the hand wheel (compare position 19 in FIG. 1), the pressure force introduced into the prosthesis part via the stop 22 , 1 can be increased somewhat, as a result of which the prosthesis part can be fixed extremely easily in the holding device 20 .

Since no push rods for power transmission to the jaws 29 , 30 are required anymore, on the one hand, the constructive structure of the holding device 20 is simplified in a favorable manner, and on the other hand, by changing the teeth 35 directly, the change in the toothing 35 can easily change the gear ratio of the individual movements to the respective requirements to adjust.

A trapezoidal toothing 35 on the rack 24 and at the ends of the struts 25 , 26 , 27 , 28 has proven to be particularly advantageous in practical use.

The embodiment of the invention is not limited to the above benen preferred embodiments. Rather, there are a number of variations possible, which of the solution shown is fundamentally different makes use of any type.

Claims (15)

1. Holding device ( 1 , 20 ), in particular for parts of the body such as a knee joint or prostheses ( 101 ) corresponding to the parts of the body, with two clamping elements ( 3 , 4 , 29 , 30 ) and a pressure element ( 11.5 , 22.1 ), which are in relation to one another are arranged so that they enclose an intermediate space ( 100 ) from three sides and via a drive device ( 7 , 8 , 9 , 10 , 14 , 15 , 16 , 17 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ) are connected to each other in such a way that when the clamping elements ( 3 , 4 , 29 , 30 ) move in the direction of the intermediate space, a clamping force acting on an object ( 101 ) located in the intermediate space is generated, characterized in that the drive device has a Lever drive comprises, such that each clamping element ( 3 , 4 , 29 , 30 ) is articulated to a drive lever ( 16 , 17 , 25 , 26 , 27 , 28 ) so that the clamping elements ( 3 , 4 , 29 , 30 ) while reducing their relative distance towards the Zw i space ( 100 ) and relative to the pressure element ( 11.5 , 22.1 ) are movable, and that the drive device has a pressure drive ( 11 , 14 or 22 , 23 ) for the pressure element ( 11.5 , 22.1 ), which is a movement of the Pressure element ( 11.5 , 22.1 ) generated in the direction of the space ( 100 ). 2. Holding device according to claim 1, characterized in that the pressure drive ( 11 , 14 or 22 , 23 ) for the pressure element ( 11.5 , 22.1 ) is coupled to the lever drive for the clamping elements ( 3 , 4 , 29 , 30 ) that the pressure element and the clamping elements ( 3 , 4 , 29 , 30 ) are simultaneously moved in the direction of the intermediate space while reducing their relative distance. 3. Holding device according to claim 1 or 2, characterized in that a drive spindle ( 14 , 23 ) is provided for the pressure drive, which at least indirectly with or with the drive levers ( 7 , 8 , 9 , 10 , 16 , 17 , 24 , 25 , 26 , 27 , 28 ) is engaged. 4. Holding device according to one of the preceding claims, characterized in that the lever drive each has a four-bar linkage ( 7 , 8 , 9 , 10 , 11 or 22 , 25 , 26 , 27 , 28 ) for parallelogram or trapezoidal guidance of the clamping elements ( 3 , 4 , 29 , 30 ), the four-bar linkage being deformable by the drive lever ( 16 , 17 ) for moving the clamping elements. 5. Holding device according to claim 4, characterized in that the Vierge joints ( 7 , 8 , 9 , 10 , 11 or 22 , 25 , 26 , 27 , 28 ) are arranged substantially mirror symmetrical to the drive spindle ( 14 , 23 ) . 6. Holding device according to claim 3, 4, or 5, characterized in that the drive spindle ( 14 ) is mounted in a guide device ( 2 ) and an axially movable displacement piece ( 15 ) is provided on the drive spindle, which by at least two push rods ( 16 , 17 ) as a drive lever are each connected to one of the four joints ( 7 , 8 , 9 , 10 , 11 or 22 , 25 , 26 , 27 , 28 ) at a point where the respective clamping element ( 3 , 4 ) engages. 7. Holding device according to claim 6, characterized in that the push rods ( 16 , 17 ) are arranged symmetrically to the drive spindle ( 14 ) and have substantially the same length. 8. Holding device according to claim 7, characterized in that the push rods ( 16 , 17 ) extend in mutually parallel planes. 9. Holding device according to one of the preceding claims, characterized in that the same drive spindle ( 14 , 23 ) is provided for the pressure drive and the lever drive. 10. Holding device according to one of the preceding claims, characterized in that between the pressure drive ( 11 ) and the sliding piece ( 15 ), preferably designed as a helical spring element ( 15.1 ) is arranged to slide back the sliding piece ( 15 ) when relaxing to facilitate the holding device. 11. Holding device according to one of claims 1, 2 or 3, characterized by a pressure drive ( 22 ) which has a rack ( 24 ) which is axially displaceable by the drive spindle ( 23 ) and which, in sections of gear-shaped ends of the clamping elements ( 29 , 30 ) engages with the pressure drive ( 22 ) connecting drive lever ( 25 , 26 , 27 , 28 ). 12. Holding device according to claim 11, characterized in that the toothed rod ( 24 ) and in the pressure drive ( 22 ) mounted ends of the drive lever ( 25 , 26 , 27 , 28 ) have a trapezoidal toothing ( 35 ). 13. Holding device according to one of the preceding claims, characterized in that the clamping elements are designed as essentially claw-shaped clamping jaws ( 3 , 4 , 29 , 30 ). 14. Holding device according to one of the preceding claims, characterized in that a hand wheel ( 19 ) is provided for actuating the drive spindle ( 14 , 23 ). 15. Holding device according to one of the preceding claims, characterized in that the pressure element ( 11.5 , 22.1 ) is exchangeably attached to the pressure drive ( 11 , 22 ).