WO2024084035A1 - Surgical instrument for resetting fractures - Google Patents

Abstract

A surgical instrument for resetting fractures comprises a carrier piece with a guide structure that defines a longitudinal axis, a hook releasably fastened to the carrier piece, a spindle movably guided in the guide structure of the carrier piece along the longitudinal axis, said spindle having an outer thread, a spindle mating piece movably mounted on the carrier and having an engagement structure that is designed to engage in the outer thread of the spindle, and an elastic preloading element that preloads the spindle mating piece into an engagement position in which the engagement structure is in engagement with the outer thread of the spindle such that the spindle can be displaced along the longitudinal axis by means of a rotation about a spindle axis parallel to the longitudinal axis, wherein the spindle mating piece can be moved into a release position in which the engagement between the outer thread and the engagement structure is released to the extent that the spindle can be displaced along the longitudinal axis through the application of an axial force directed along the spindle axis.

Description

DESCRIPTION

Title

Surgical instrument for reducing fractures

Technical area

The present invention relates to a surgical instrument for repositioning fractures, e.g. for aligning or generally for moving individual bone parts or fragments.

State of the art

In the case of broken bones or fractures, it may be necessary to realign or reposition the individual fragments during a surgical procedure. Instruments with a hook and a mandrel are usually used for this purpose, whereby the hook and mandrel can be moved relative to each other in order to reposition the bone parts using the hook and mandrel.

CN 2 117 861 U describes a surgical tool for setting bone screws. The tool has a fixation instrument for fixing the bone fragments to be screwed. The fixation instrument comprises an inner tube, which is provided with an external thread at a rear end and has an elongated recess in a central region, and an outer tube, which is slidably guided on the inner tube and has an elongated recess. An arcuate fixation hook is attached to a front end of the inner tube. A rod is slidably guided inside the inner tube, the front end of which is designed to rest against a bone fragment and which is provided with transverse grooves in a central region. A pivotable lever is provided on the outer tube, which is preloaded by a spring into an engagement position in which one end of the lever is in engagement with the transverse grooves of the rod. An axial position of the outer tube relative to the inner tube can be fixed by means of a flange nut which is screwed onto the thread at the rear end of the inner tube.

Another surgical instrument for holding a connecting plate on a broken bone is described in EP 0 686 375 A1, in which a tube piece is slidably guided on a rod with an external thread and a hook provided at the end, said tube piece having a second hook section for counter-holding. A wing nut is screwed onto the external thread of the rod, by means of which a force can be applied to the tube piece in the axial direction, which generates a clamping force between the hook sections.

The displacement or tensioning of a clamping element guided on a hook via a clamping nut which engages with an external thread provided on the hook is also described in DE 299 16 202 U1.

EP 2 844 166 A1 describes a positioning instrument with a box, a first rod which is guided through a passage of the box and is axially displaceable relative to the box, and a second rod which is displaceably guided on the first rod. The first rod has transverse grooves on its outer circumference and can be locked to the box by means of a pre-tensioned lever which engages in the transverse grooves. The first rod also has an axial bore through which the second rod protrudes. The second rod is provided with an external thread and can be axially displaced by means of a nut which is fixedly positioned relative to the first rod. US 2 427 128 A discloses a surgical instrument for reducing fractures, wherein an elastic prestressing element prestresses a spindle or a toothed arc segment in the direction of an actuating handle.

Disclosure of the invention

It is an object of the present invention to provide an improved instrument for reducing fractures, in particular an instrument which is practical to handle and at the same time facilitates a precisely dosed application of force.

This object is achieved in each case by an instrument having the features of claim 1.

According to the invention, a surgical instrument for reducing fractures comprises a carrier piece with a guide structure defining a longitudinal axis, a hook detachably attached to the carrier piece, a spindle which is movably guided in the guide structure of the carrier piece along the longitudinal axis and which has an external thread, a spindle counterpart which is movably mounted on the carrier and has an engagement structure which is designed to engage in the external thread of the spindle, and an elastic prestressing element which prestresses the spindle counterpart into an engagement position in which the engagement structure is in engagement with the external thread of the spindle, so that the spindle can be displaced along the longitudinal axis by rotation about a spindle axis parallel to the longitudinal axis, e.g. coaxial, wherein the spindle counterpart can be moved into a release position in which the engagement between the external thread and the engagement structure is released to such an extent that the spindle can be released by applying an axial force directed along the spindle axis. force can be moved along the longitudinal axis, in particular without rotating the spindle about the spindle axis.

The spindle is mounted on the support piece so that it can be moved along the longitudinal axis in the guide structure. Together with the hook, which is detachably attached to the support piece, a distance between a working end of the spindle and a working end of the hook facing away from the support piece can be varied by linearly moving the spindle along the longitudinal axis, e.g. reduced in order to reposition or reduce a fracture using the working ends.

According to the invention, the spindle has an external thread which engages with an engagement structure of a spindle counterpart mounted on the carrier and prestressed by a prestressing element. The prestressing element is coupled to the spindle counterpart in such a way that it applies a prestressing force to the spindle counterpart and thereby prestresses it into an engagement position. The prestressing element can, for example, be supported on the carrier piece and on the spindle counterpart. The spindle counterpart can be moved into a release position against the prestressing force of the prestressing element. When the engagement structure is engaged with the external thread of the spindle, the spindle can be moved linearly by rotating it about its spindle longitudinal axis, for example in order to be able to precisely apply a desired force to the fracture. If rapid adjustment of the spindle along the longitudinal axis is desired, the spindle counterpart can be moved into the release position so that it allows linear displacement of the spindle without rotation about the spindle longitudinal axis. One advantage of the invention is that the spindle can be adjusted quickly to cover a larger distance, as well as precisely in small distance ranges. This facilitates the simple and quick handling of the instrument.

Advantageous embodiments and further developments arise from the subclaims which refer back to the independent claims in conjunction with the description.

According to advantageous embodiments, it can be provided that the guide structure is formed by a recess in the carrier piece. This ensures that the spindle is guided securely. The recess can be formed, for example, as a hole with a circular cross-section. However, other cross-sectional shapes are also conceivable.

According to advantageous embodiments, it can be provided that the guide structure extends continuously between a first end and a second end of the carrier piece. For example, the bore or generally the recess can extend over the entire length of the carrier piece.

According to advantageous embodiments, the spindle can be moved with a working end beyond the second end of the carrier piece, so that the fracture can be repositioned by the working end of the spindle and an end region of the hook facing away from the carrier, with an actuating end of the spindle opposite the working end protruding beyond the first end of the carrier piece. The spindle thus extends over the entire length of the carrier piece. For example, the actuating end can be provided with a handle to facilitate turning and pushing the spindle. According to advantageous embodiments, it can be provided that the working end of the spindle can be moved into the guide structure of the carrier piece. In this way, a maximum possible working area is realized between the hook and the spindle. Furthermore, the working area can be flexibly adapted, e.g. by means of a shorter spindle and/or different hooks.

According to advantageous embodiments, it can be provided that the working end of the spindle has a locking piece, in particular in the form of a ball, with which an attachment, in particular in the form of a plate, can be locked, wherein the guide structure at the second end of the carrier piece preferably has a receptacle through which the working end of the spindle can be moved in the direction of the first end of the carrier part, so that the attachment locked with the locking piece can be released from the spindle in the receptacle, in particular pulled off. The receptacle can be formed, for example, by an end region of the guide structure. For example, if the guide structure is designed in the form of a bore or generally by a recess, the recess can have a widening at its axial end. The attachment locked with the working end of the spindle can be inserted into this receptacle by moving the spindle into the guide structure and can be stripped off the spindle therein. An advantage of this design is that the attachment can be removed without tools, which, for example, reduces the risk of injury.

According to advantageous embodiments, it can be provided that the spindle has a first spindle part, on which the external thread is formed, and a second spindle part, which is guided on the first spindle part so as to be linearly movable and is preloaded by a spring against movement in the direction of the first spindle part. The first and the second spindle part are thus resiliently mounted relative to each other. As a result, a force applied to the fracture by the spindle can be limited cushioned, e.g. if the working end of the spindle accidentally comes into contact with the fracture during quick adjustment.

According to advantageous embodiments, it can be provided that the carrier piece has a flat or substantially flat first surface and a flat or substantially flat second surface which is oriented opposite to the first surface, wherein the longitudinal axis runs parallel to the first and second surfaces. The carrier piece can in particular be designed as a substantially plate-shaped part, wherein the guide structure extends along the surfaces. In particular, the recess, which optionally forms the guide structure, can run in the material between the first and second surfaces.

According to advantageous embodiments, the carrier piece can be designed as a handle. The carrier piece therefore fulfils both the function of a handle by which the instrument can be held and the function of guiding the spindle and holding the hook. This further facilitates handling of the instrument and achieves a more compact structure.

According to advantageous embodiments, it can be provided that the spindle counterpart is mounted on the carrier piece in such a way that the engagement structure is movable between the engagement position and the release position in a direction transverse to the longitudinal axis.

According to advantageous embodiments, it can be provided that the engagement structure is formed at a first end of the spindle counterpart and a second end protrudes from the carrier piece with respect to a transverse direction extending perpendicular to the longitudinal axis. Thus, the spindle counterpart can be can be easily operated from the edge or side of the carrier piece to disengage the engagement structure from the external thread of the spindle. This further simplifies the operation of the instrument.

According to advantageous embodiments, it can be provided that the spindle counterpart is mounted on the carrier piece so that it can rotate about an axis of rotation extending perpendicular to the longitudinal axis. For example, the spindle counterpart can be designed as a type of rocker arm, which facilitates simple operation. It can also optionally be provided that the axis of rotation is formed between a first end and a second end of the spindle counterpart. If the spindle counterpart protrudes laterally beyond the carrier piece with the second end, the engagement structure can thus be released from the external thread of the spindle, for example by moving the second end of the spindle counterpart in the direction of the carrier piece. This further facilitates intuitive and simple operation of the instrument.

According to advantageous embodiments, it can be provided that the spindle counterpart is mounted on the carrier piece in a linear guide extending transversely to the longitudinal axis so that it can be moved linearly. This design also allows easy handling for moving the spindle counterpart from the engagement position into the release position.

According to advantageous embodiments, it can be provided that the engagement structure has a plurality of engagement elements, in particular in the form of teeth or pins, which can be brought into engagement with the external thread. This offers the advantage that the axial force can be better supported on the engagement structure. According to advantageous embodiments, it can be provided that the engagement elements have at least one sliding surface which, with respect to the longitudinal axis, faces a first end of the carrier piece and is inclined in such a way that the external thread of the spindle slides along the sliding surface when an axial force is applied along the spindle axis from the first end towards a second end of the carrier piece, so that the engagement structure is moved from its engagement position to its release position. The engagement structure can thus be disengaged in one direction, namely in the direction from the rear, first end to the front, second end of the carrier piece, by an axial force on the spindle. This means that the spindle can thus be pushed through in one direction without actively actuating the spindle counterpart, which further facilitates handling.

According to advantageous embodiments, it can be provided that the carrier piece has a holder with a receiving gap and a linearly movable locking bolt, wherein the hook has a connecting piece positioned in the receiving gap with a locking opening into which the locking bolt protrudes in a locking position or locking position in order to fix the hook to the carrier piece. The hook is thus detachably, in particular positively connected to the carrier piece via the connecting piece, which is attached to one end of the hook. By fixing the connecting piece by means of a locking bolt in the receiving gap, an easily detachable but reliable connection is realized.

According to advantageous embodiments, it can be provided that the connecting bolt can be moved out of the locking opening of the connecting piece of the hook without tools by applying a pulling force, so that the hook can be removed from the carrier piece. This further facilitates the handling of the instrument. According to advantageous embodiments, it can be provided that the holder has a first block with a passage in which the locking bolt is guided, and a second block spaced from the first block by the receiving gap, wherein the locking bolt has a head located outside the receiving gap for applying the tensile force. The bolt can thus be moved out of the receiving gap on the head without the need to use a tool.

According to advantageous embodiments, it can be provided that the locking bolt is secured in a form-fitting manner to the first block in the locking position and in a retracted position in which the locking bolt is retracted from the receiving gap, i.e. does not protrude into the locking opening, against falling out of the passage. For example, the bolt can be provided with a groove in which a first and a second recess are formed at a distance from one another, with a securing element, e.g. in the form of a ball, being held on the first block, which protrudes into the groove and is pre-tensioned into the groove by a spring. When the locking bolt is positioned in the locking position, the securing element engages in the first recess; when the locking bolt is positioned in the retracted position, the securing element engages in the second recess. The protection against falling out further facilitates the handling of the instrument, in particular the preparation of the instrument, e.g. the disinfection of the device.

According to advantageous embodiments, it can be provided that the holder and the connecting piece are designed in such a way that the connecting piece can be fixed to the holder in several rotational positions with respect to a central axis of the locking bolt. For example, the holder and the connecting piece can each have contact surfaces which lie against one another and thereby ensure a positive fixation with respect to rotation about the central axis. Optionally, the holder can be provided with different contact surfaces that enable fixation in different rotational positions.

According to advantageous embodiments, the surgical instrument can have an actuating piece for applying a torque to the spindle and a torque limiter which couples the actuating piece to the spindle and is designed to allow a relative rotation between the spindle and the actuating piece when the torque applied to the actuating piece exceeds a predetermined threshold value. As a result, the force applied by the spindle to the fracture can be limited in a simple and effective manner. This further facilitates the dosage of the force applied by the instrument.

With regard to directional information and axes, in particular directional information and axes relating to the course of physical structures, the course of an axis, a direction or a structure "along" another axis, direction or structure is understood to mean that these, in particular the tangents resulting at a respective point of the structures, each run at an angle of less than or equal to 45 degrees, preferably less than or equal to 30 degrees and particularly preferably parallel to one another.

With regard to directions and axes, in particular directions and axes relating to the course of physical structures, the course of an axis, a direction or a structure "transversely" to another axis, direction or structure is understood to mean that these, in particular the tangents resulting at a respective point of the structures, are each at an angle of greater than 45 degrees, preferably greater than or equal to 60 degrees and particularly preferably perpendicular to each other.

Brief summary of the drawings

The invention is explained below with reference to the figures of the drawings. The figures show:

Fig. 1 is a perspective view of a surgical instrument according to an embodiment of the present invention;

Fig. 2 is a sectional view of the instrument shown in Fig. 1;

Fig. 3 is a detailed view of the area indicated by the letter Z in Fig. 2;

Fig. 4 is a sectional view of a surgical instrument according to another embodiment of the present invention;

Fig. 5 is a partial plan view of a surgical instrument according to another embodiment of the present invention;

Fig. 6 is a sectional view of a surgical instrument according to a

Embodiment of the present invention in the region of a second end of a carrier piece of the instrument; Fig. 7 shows the instrument from Fig. 1, with a hook of the instrument shown in a rotated position;

Fig. 8A is a partial view of a surgical instrument according to another embodiment of the present invention;

Fig. 8B is a partial view of a surgical instrument according to another embodiment of the present invention;

Fig. 9 is a partial view of a surgical instrument according to another embodiment of the present invention;

Fig. 10 is a partial view of a surgical instrument according to another embodiment of the present invention;

Fig. 11 is a partial view of a surgical instrument according to another embodiment of the present invention;

Fig. 12 is a sectional view of a surgical instrument according to a

Embodiment of the present invention in the region of a second end of a carrier piece of the instrument;

Fig. 13 is a partial view of a surgical instrument according to another embodiment of the present invention;

Fig. 14 is a perspective view of a surgical instrument according to another embodiment of the invention; Fig. 15 is a perspective view of a surgical instrument according to another embodiment of the invention;

Fig. 16 is a perspective view of a surgical instrument according to another embodiment of the invention;

Fig. 17 is a side view of a surgical instrument according to another embodiment of the invention;

Fig. 18 is a partial view of the instrument shown in Fig. 17 in a

sectional view; and

Fig. 19 is a partial representation of a surgical instrument according to a further embodiment of the invention in a sectional view.

In the figures, the same reference symbols designate identical or functionally identical components, unless otherwise stated.

Description of implementation examples

Fig. 1 shows an example of a surgical instrument 100 for reducing fractures. As shown in Fig. 1, the instrument 100 has a carrier piece 1, a hook 2, a spindle 3 and a spindle counterpart 4. Furthermore, the instrument 100 comprises, as shown in Figs. 2 and 3, an elastic prestressing element 5.

The carrier piece 1 can, as shown by way of example in Figs. 1 and 2, be designed, for example, as a plate-shaped part with a substantially T-shaped circumference. In general, the carrier piece 1 can extend between a first end 11 and a second end 12 in a longitudinal direction. Optionally, the carrier piece 1 has a flat or substantially flat first surface 1a and a flat or substantially flat second surface 1b which is oriented opposite to the first surface 1a, as shown by way of example in Fig. 1. The first and second surfaces 1a, 1b are connected by a peripheral surface 1c which defines the outer circumference of the carrier piece 1. Optionally, the carrier piece 1 can have a plurality of openings 13 which are adjacent in the longitudinal direction and extend between the first and second surfaces 1a, 1b. The carrier piece 1 can in particular be designed as a handle. For example, the carrier piece 1 can have recesses 1d in the peripheral surface 1c, as shown by way of example in Fig. 1, or a general structure. Alternatively or additionally, the outer circumference of the carrier piece 1 can have lateral projections 19, as shown purely by way of example in Fig. 1, in order to make it easier to grip the carrier piece 1 by hand.

The carrier piece 1 generally has a guide structure 10 which defines a longitudinal axis A1. The longitudinal axis A1 extends, as shown in Fig. 1, between the first and the second end 11, 12 of the carrier piece 1. In particular, the longitudinal axis A1 can extend parallel to the first and the second surface 1a, 1b of the carrier piece 1. As shown schematically in Figs. 1 and 2, the guide structure 10 can be formed, for example, by a bore or generally a recess 10A in the carrier piece 1. For example, the recess 10A or generally the guide structure 10 can extend continuously from the first to the second end 11, 12 of the carrier piece 1, as is shown by way of example in Fig. 1. As shown schematically in Fig. 12 and explained in detail later, the recess 10A, which in the example shown is realized as a bore, can be widened at the second end 12 of the carrier piece 1 in order to form a receptacle 12A. The carrier piece 1 can in particular be made of a metal material, for example of stainless steel, titanium or the like. It would also be conceivable for the carrier piece 1 to be made of a plastic material.

The hook 2 is used to apply a force or to move the fracture, in particular a bone fragment. As shown in Fig. 1 purely by way of example, the hook 2 can extend between a first end 21 and a second end 22, the hook 2 having a curved, for example essentially U-shaped section 2A at least in the region of the second end 22. The hook 2 shown in Fig. 1 purely by way of example has a first, at least partially linear section 2A, which extends from the first end 21, and the curved section 2B adjoining the linear section 2A, which has the second end 22. The invention is not limited to this hook shape. In Figs. 8 to 11, further hooks 2 are shown by way of example, which are explained in more detail below.

The hook 2 is detachably attached to the carrier piece 1. In particular, the hook 2, as shown schematically in Fig. 1, can be attached to the carrier piece 1 at its first end 21, in particular in the region of the second end 12 of the carrier piece 1.

As shown by way of example in Fig. 1, the carrier piece 1 can, for example, have a holder 14 to which the hook 2 is releasably fixed by means of a locking bolt 17. Fig. 6 shows a schematic sectional view in the region of the second end 12 of the carrier piece 1 through the holder 14 and the hook 2. In general, the holder 14 has a receiving gap 14A, which can be defined, for example, as in Fig. 6, by a first block 15 and a second block 16. The first and second blocks 15, 16 can, for example, protrude from the first surface 1a of the carrier 1 and be spaced apart along the longitudinal axis A1. The first block 15 has a passage 15A. The The second block 16 optionally has an opening 16A positioned coaxially to the passage 15A. The locking bolt 17 is mounted in the passage 15A so as to be linearly movable.

As further shown in Fig. 6, the hook 2 can be provided at its first end 21 with a connecting piece 24 which can be inserted into the gap 14A and has a locking opening I. The connecting piece 24 can, for example, have a shape corresponding to the gap 14A. The locking bolt 17 is movable between a locking position, which is shown in Fig. 6, and a retracted position. In the locking position, the locking bolt 17 projects through the locking opening ZI of the connecting piece 24 of the hook 2 and optionally additionally into the opening 16A of the second block 16, as shown in Fig. 6. In this position of the locking bolt 17, the hook 2 is fixed to the carrier piece 1. In the retracted position, the locking bolt 17 is retracted from the receiving gap 14A and thus also from the locking opening ZI, so that the hook 2 can be removed from the carrier piece 1.

As shown schematically in Fig. 6, the locking bolt 17 can have a head 17A, which forms an end of the locking bolt 17 that protrudes from the block 15 outside the receiving gap 14A. A user can grip the locking bolt 17 at this head 17A and apply a pulling force to move it into the retracted position. The connecting bolt 17 can generally be moved out of the locking opening ZI of the connecting piece 24 of the hook 2 without tools by applying a pulling force.

Furthermore, it can be provided that the locking bolt 17 is secured in a form-fitting manner to the first block 15 in the locking position and in the retracted position against falling out of the passage 15A. For example, as shown purely by way of example in Fig. 6, a securing element 18 can be provided in the first block 15 which is guided perpendicular to a central or longitudinal axis M17 of the bolt 17 and is prestressed by means of a spring (not shown) such that it projects into a groove 18A extending along the longitudinal axis M17 of the locking bolt 17 and rests on the bottom of the groove 18A. The securing element 18 can be, for example, a ball, a pin or the like. A first and a second notch 18B, 18C are formed at axial ends of the groove 18A. When the locking bolt 17 is positioned in the locking position, as shown in Fig. 6, the securing element 18 engages in the first notch 18B. When the locking bolt 17 is positioned in the retracted position, the securing element 18 engages in the second notch 18C.

Furthermore, the holder 14 and the connecting piece 24 can optionally be designed such that the connecting piece 24 can be fixed to the holder 14 in several rotational positions with respect to a central axis of the locking bolt 17. In Fig. 1, for example, it is shown that the hook 2 is fixed to the holder 14 such that the curved section 2B lies in a plane that extends perpendicular to the first surface 1a of the carrier piece 1 or parallel to a vertical direction H1 of the holder. In Fig. 7, however, it is shown that the hook 2 is fixed to the holder 14 such that the curved section 2B lies in a plane that extends parallel to the first surface 1a of the carrier piece 1 or parallel to a transverse direction C1 of the holder. A vertical axis A24 of the connecting piece 24 therefore extends parallel in Fig. 7 and therefore perpendicular to the first surface 1a of the carrier piece 1 in Fig. 1.

The fixing in the different rotational positions can be achieved, for example, by means of a positive connection as a result of contact surfaces 14k, 24k lying against one another, as is shown schematically in Fig. 6. In the rotational position shown in Figs. 6 and 1, a flat contact surface 24k of the connecting piece 24 lies on a flat first Contact surface 14k of the holder 14, which is oriented away from the first surface 1a of the carrier piece 1 and runs parallel to it. In the rotational position shown in Fig. 7, the flat contact surface 24k of the connecting piece 24 rests against a flat second contact surface 141 of the holder 14 (Fig. 1), which runs perpendicular to the first surface 1a of the carrier piece 1. Other fixing options in different rotational positions are also conceivable, e.g. via corresponding polygonal shapes of the locking bolt 17 and the locking opening I of the connecting piece 24.

The spindle 3 extends along a spindle axis A3 between a working end 31 and an actuating end 32. As shown in Fig. 1, the spindle 3 has an external thread 30, e.g. a metric thread, a round thread, a sawtooth thread, a flat thread, a trapezoidal thread, a tapered thread, a Whitworth thread, a pipe thread or the like. As shown in Figs. 1 and 2, the external thread 30 can optionally be formed only in part of the length of the spindle 3. At the working end 31, the spindle 3 can optionally have a ball head with a point, as shown purely by way of example in Figs. 1 and 2. The working end 31 serves to apply a force to the fracture together with the end 22 of the hook 2 in order to reposition it. At the actuating end 32 of the spindle 3, an actuating piece 36, e.g. in the form of a handle as in Figs. 1 and 2 shown schematically.

As shown in particular in Fig. 2, the spindle 3 is guided in the guide structure 10 of the carrier piece 1 so as to be movable along the longitudinal axis A1. In particular, the spindle 3 extends through the recess 10A. The spindle axis A3 is parallel, in particular coaxial, to the longitudinal axis A1. As shown in Figs. 1 and 2, it can be provided that the spindle 3 has a length between its working end 31 and its actuating end 32 that is greater than a length of the carrier piece 1 along the longitudinal axis A1 between the first and the second end 11, 12. In general, the spindle 3 with the working end 31 can be moved beyond the second end 12 of the carrier piece 1, so that the fracture can be repositioned by the working end 31 of the spindle 3 and the second end 22 of the hook 2. At the same time, the actuating end 32 of the spindle 3 protrudes beyond the first end 11 of the carrier piece 1, as shown in Figs. 1 and 2. Furthermore, it can also be optionally provided that the working end 31 of the spindle 3 can be moved into the guide structure 10 of the carrier piece 1. The spindle 3 can thus be retracted so far that it no longer protrudes beyond the second end 12 of the carrier piece 1. For example, the spindle 3 at the first end 11 of the carrier piece 1 can be pulled out of the guide structure 10 or the recess 10A.

The spindle counterpart 4 and the elastic prestressing element 5 can be seen in Figs. 2 and 3. The spindle counterpart 4 has an engagement structure 40 which is designed to engage in the external thread 30 of the spindle 3. As is shown in particular in Fig. 3 by way of example, the engagement structure 40 can have a plurality of engagement elements 40A, e.g. in the form of teeth as shown purely by way of example in Fig. 3, which are adapted in their shape and arrangement to the pitch and the flank shape of the threads of the external thread so that they can be brought into engagement with the external thread 30. As an alternative to teeth 43, other engagement elements, e.g. in the form of pins or the like, could also be provided.

As shown by way of example in Figs. 2 and 3, the spindle counterpart 4 can generally be an elongated component that extends between a first end 41, on which the engagement structure 40 is formed, and a second end 42. The spindle counterpart 4 is movably mounted on the carrier piece 1. For example, the carrier piece 1 can have a recess 45, e.g. as an opening in the peripheral surface 1c, in which the spindle counterpart 4 is movably mounted. The The spindle counterpart 4 can, for example, be mounted on the carrier piece 1 so as to be rotatable about an axis of rotation A4 extending perpendicular to the longitudinal axis A1. This is shown by way of example in Figs. 2 and 3, wherein the carrier piece 1 is here mounted so as to be rotatable between its first and second ends 41, 42 about the axis of rotation A4, which extends perpendicular to the first surface 1a of the carrier piece 1. Alternatively, it can also be provided that the spindle counterpart 4 is mounted on the carrier piece 1 so as to be linearly displaceable in a linear guide (not shown) extending transversely to the longitudinal axis A1, e.g. along the holder transverse direction C1. The second end 42 can, for example, protrude laterally beyond the carrier piece 1 or the peripheral surface 1c with respect to the holder transverse direction C1, which extends generally transversely to the longitudinal axis A1, as is shown in Fig. 3 by way of example for the rotatably mounted spindle counterpart 4.

The spindle counterpart 4 is generally movable between an engagement position, which is shown in Fig. 3, and a release position. In the engagement position, the engagement structure 40 is in engagement with the external thread 30 of the spindle 3. In the example of Fig. 3, the engagement elements 40A thus engage in the external thread 30 of the spindle 3. As a result, the spindle 3 can be displaced along the longitudinal axis A1 by rotating about its spindle axis A3, e.g. in order to apply force to a fracture via the working end 31 with the hook 2 as a counter bearing. In the release position (not shown), the engagement between the external thread 30 and the engagement structure 40 is canceled at least to the extent that the spindle 3 can be displaced along the longitudinal axis A1 by applying an axial force directed along the spindle axis (A3), in particular without rotating the spindle 3 about the spindle axis.

The elastic pre-tensioning element 5 can be designed as a spring, e.g. as a leg spring, as shown in Fig. 3, or as a leaf spring, torsion spring, spiral spring or the like. The pre-tensioning element 5 pre-tensions the spindle counterpart 4 into the engagement position. For example, as shown in Fig. 3, the preloading element 5 can be supported on the carrier piece 1 and on the spindle counterpart 4 and apply a preload force to the spindle counterpart 4. In the example of Fig. 3, the preloading element 5 applies a force directed away from the longitudinal axis A1 between the axis of rotation A4 and the second end 42 to the spindle counterpart 4, which causes the engagement structure 40 provided on the first end 41 to be held in engagement with the external thread 30 of the spindle 3.

To move the spindle counterpart 4 from the engagement position into the release position, a force directed opposite to the preload force of the preload element 5 can be applied to the second end 42 of the spindle counterpart 4, for example by a user moving the second end 42 of the spindle counterpart 4 in the direction of the carrier piece 1 with respect to the holder transverse direction C1. In general, it can be provided that the spindle counterpart 4 is mounted on the carrier piece 1 in such a way that the engagement structure 40 can be moved between the engagement position and the release position in a direction transverse to the longitudinal axis A1. It is also conceivable that the force required to move the spindle counterpart 4 from the engagement position into the release position is applied via the spindle 3. For example, the engagement elements 40A can have at least one sliding surface which, with respect to the longitudinal axis A1, faces the first end 11 of the carrier piece 1 and is inclined such that the external thread 30 of the spindle 3 slides along the sliding surface when an axial force is applied along the spindle axis A3 from the first end 11 in the direction of the second end 12 of the carrier piece 1, thereby displacing the engagement structure 40 outwardly transversely to the longitudinal axis A1, so that the engagement structure 40 is moved from its engagement position to its release position. Regardless of how the spindle counterpart 4 is moved from the engagement position to the release position, a linear movement of the spindle 3 along the longitudinal axis A1 can take place in the release position without having to rotate the spindle 3. This makes it easier to quickly cover larger distances.

Optionally, a securing element 44 can be provided which secures the spindle counterpart 4 in the engaged position against movement into the release position. As shown by way of example in Fig. 4, the securing element 44 can be designed, for example, as a screw which fixes the spindle counterpart 4 to the carrier piece 1. If the spindle counterpart 4 is rotatably mounted on the carrier piece 1, as shown by way of example in Fig. 4, the securing element 44 can, for example, be guided through the spindle counterpart 4 in the region of the second end 42 and be supported on the carrier piece 1.

While instruments 100 with only one spindle counterpart 4 are shown in Figs. 1 to 4, the invention is not limited to this. Fig. 5 shows an example of an instrument 100 which has a first and a second spindle counterpart 4A, 4B, which are arranged on opposite sides of the carrier piece 1 with respect to the holder transverse direction C1. The mode of operation is identical to the mode of operation with only one spindle counterpart 4, wherein in Fig. 5 an engagement structure 40 of the first and second spindle counterpart 4A, 4B engages in the external thread 30 of the spindle 3.

As already explained, the carrier piece 1 can be combined with various hooks 2. These can, for example, be releasably fixed to the holder 14 in the manner described. In Figs. 1, 7 and 8A, a hook 2 is shown, the second end 22 of which is positioned coaxially to the spindle axis A3 or longitudinal axis A1. Fig. 8B shows, by way of example, a hook 2, the second end 22 of which is positioned at a distance d22 from the spindle axis A3 or longitudinal axis A1. The second end 22 is on the side of the first surface 1a of the carrier piece 1. Fig. 9 shows a hook 2 in which the curved section 2B has a significantly larger radius than in Figs. 1, 7 and 8 and whose second end 22 is positioned at a distance d22 from the spindle axis A3 or longitudinal axis A1 on the side of the second surface 1b of the carrier piece 1.

In Figs. 1 and 7 to 9, the hooks 2 each extend in one plane, e.g. in a plane containing the longitudinal axis A1. Fig. 10 shows an example of a hook 2 which has a first linear section 2C which extends from the first end 21 of the hook 2 in the plane containing the longitudinal axis A1, and a second linear section 2D which extends at an angle from one end of the first linear section 2A. Fig. 11 shows an example of a hook 2 which also has a first and a second linear section 2C, 2D, the first linear section 2C extending from the first end 21 of the hook 2 in the plane containing the longitudinal axis A1. The second linear section 2D is connected to the first linear section 2C by a connecting section 2E which extends from the end of the first linear section 2C at an angle thereto and extends parallel to the plane containing the longitudinal axis A1.

As already explained above, it can optionally be provided that the working end 31 of the spindle 3 can be moved into the guide structure 10 of the carrier piece 1. The guide structure 10 can optionally have a receptacle 12A at the second end 12 of the carrier piece 1. As shown schematically and purely by way of example in Fig. 12, the receptacle 12A can be formed, for example, by an end region of the recess 10A, which optionally has a larger diameter than the rest of the recess 10A. This receptacle 12A can be used, for example, to strip an attachment 35 from the working end 31 of the spindle 3. The working end 3 of the spindle 3 can optionally have a locking piece 34, e.g. in the form of a ball, which in the present Example of Fig. 12 is additionally provided with a point. In principle, other locking pieces 34, e.g. lugs, brackets, grooves, rockers, etc. are also conceivable. An attachment 35, e.g. in the form of a plate as shown in Fig. 12, can have a locking structure 35A complementary to the locking piece 34, e.g. in the form of a recess, which can be locked to the locking piece 34. When the working end 31 of the spindle 3 can be moved in the direction of the first end 11 of the carrier part 1, the attachment 35 comes into contact with the second end 12 of the carrier part 1, while the part locked to the locking piece 34 is moved into the receptacle 12A and is released from the spindle 3, in particular pulled off.

Although only one-piece spindles 3 have been explained so far, the invention is not limited to this. Optionally, the spindle 3 can have a first spindle part 3A, on which the external thread 30 is formed, and a second spindle part 3B, which is guided so as to be linearly movable on the first spindle part 3A. This is shown by way of example and schematically in Fig. 13. The second spindle part 3B has the working end 31. For example, it can be provided that one of the spindle parts 3A, 3B has a bore 33A positioned coaxially to the spindle axis A3, e.g. the first spindle part 3A, as shown in Fig. 13, and the other of the spindle parts 3A, 3B has a guide shaft 33B, in Fig. 13 the second spindle part 3B, which is guided in the bore 33A. Furthermore, it can be provided that the bore 33A is connected to the outer circumference of the respective spindle part 3A, 3B by an elongated hole 33C, and a locking pin 33D is guided in the elongated hole 33C, which is connected to the guide shaft 33B of the other spindle part 3A, 3B. The spindle parts 3A, 3B can be preloaded away from each other by means of a spring 33, i.e. against a movement of the spindle parts 3A, 3B towards each other. When the working end 31 comes into contact with a bone part, the force applied is thus limited by the spring 33 until the spring travel and/or the guide path defined by the bore 33A and the guide shaft 33B has come to an end. Figs. 14 and 15 each show an instrument 100 which is constructed as explained above and additionally has a clamp 6 for attaching a connecting rod (not shown) via which the instrument 100 can be connected to another instrument 100. The clamp 6 can be attached, for example, to the first block 15 of the holder 14, as shown by way of example in Fig. 14. Alternatively, the clamp 6 can also be provided in the region of the second end 12 of the carrier 1 on its second surface 1b, as shown by way of example in Fig. 15. As a further alternative, it is also conceivable that the clamp 6 is attached to the hook 2, e.g. to its connecting piece 24.

Fig. 16 shows an example of a further surgical instrument 100, which differs from the instrument 100 shown in Figs. 1 and 2 only by the connection of the optional actuating piece 36 to the spindle 3.

As shown schematically in Fig. 16, the instrument 100 can optionally additionally have a torque limiter 7. The torque limiter 7 is connected to the actuating end 32 of the spindle 3. The torque limiter 7 can in particular be detachably connected to the actuating end 32 of the spindle 3, for example via a coupling 38, e.g. in the form of an AO coupling, W, Dental, Hudson, ZIH, WA coupling or the like, as shown by way of example in Fig. 16. Alternatively, the torque limiter 7 can also be firmly connected to the actuating end 32 of the spindle 3. The actuating piece 36 is firmly or detachably connected to the torque limiter 7. The torque limiter 7 thus couples the actuating piece 36 to the spindle 3.

The torque limiter 7 may, for example, have an input element (not shown) connected to the actuating piece 36 and an output element (not shown) which is connected to the spindle 3. The output and input elements can, for example, be in frictional contact and be preloaded against one another so that they slide against one another when a predetermined threshold is reached when a torque is applied to the output and input elements. The input and output elements and consequently spindle 3 and actuating piece 36 can thus rotate against one another when a predetermined torque is exceeded. Of course, a different structural design of the torque limiter 7 is also conceivable. In general, the torque limiter 7 is designed to permit a relative rotation between the spindle 3 and the actuating piece 36 when the torque applied to the actuating piece 36 exceeds a predetermined threshold value.

Figs. 17 to 19 show examples of further surgical instruments 100 which differ from the instrument 100 shown in Figs. 1 and 2 only by an optional stop 39 provided on the spindle 3. As shown schematically in Fig. 17, the stop 39 can be provided on the outer circumference of the spindle 3. The stop 39 can, for example, be designed as a component separate from the spindle 3 which is detachably connected to the spindle 3. For example, the stop 39 can have two ring segments which can be screwed together in order to be clamped to the spindle 3. Alternatively, the stop 39 can also be formed integrally with the spindle 3. The spindle 3 can, for example, have a radial collar which forms a projection in the outer circumference of the spindle 3, as shown schematically and purely by way of example in Figs. 18 and 19.

As shown in Figs. 17 to 19, the stop 39 can be arranged in an area facing away from the working end 31. The first end 11 or the peripheral surface 1c of the carrier piece 1, as shown by way of example in Figs. 17 and 18. Alternatively, it is also conceivable that the guide structure 10 itself functions as a counter bearing. For example, the recess 10A can be widened in the region of the first end 11 of the carrier piece 1, so that between the first and the second end 11, 12 of the carrier piece 1 a shoulder 10B is formed in the recess 10A, against which the stop 39 of the spindle 3 strikes when the spindle 3 moves in the direction of the second end 12 of the carrier piece 1, as is shown schematically in Fig. 19.

Although the present invention has been explained above by way of example using exemplary embodiments, it is not limited to this, but can be modified in many different ways. In particular, combinations of the above exemplary embodiments are also conceivable. In particular, the functioning of the instrument 100 was explained above merely by way of example in that the fracture is acted upon jointly by means of the hook 2 and the spindle 3. However, the instrument 100 can also be used with just the spindle 3, while the hook 2 is dismantled from the carrier piece 1. Conversely, the spindle 3 can also be dismantled from the carrier piece 1 and only the hook 2 can be attached to the carrier piece 1. Thus, the instrument 100 can in principle be used in three different configurations, namely as a combination instrument with hook 2 and spindle 3, as a so-called single-prong with only the hook 2, or as a so-called ball spike with only the spindle 3.

Reference symbols (excerpt):

100 Surgical Instrument

1 carrier piece

A1 Longitudinal axis

10 Management structure

2 hooks

3 spindle

30 external thread

4 spindle counterpart

40 Intervention structure

5 Preload element

A3 spindle axis

10A recess

11 first end of the carrier piece

12 second end of the support piece

31 End of work

22 End area

32 End of operation

34 Locking piece

35 Essay

12A recording

3A first spindle part

3B second spindle part

33 Spring

1a first surface

1 b second surface

41 first end of spindle counterpart 42 second end of spindle counterpart

C1 Holder cross direction

A4 rotation axis

40A engagement elements

14 holders

14A receiving slot

17 Locking bolt

24 Connector

27 Locking opening

15 first block

15A continuity

16 second block

17A Head

36 Actuator

7 Torque limiter

Claims

CLAIMS Surgical instrument (100) for repositioning fractures, comprising: a carrier piece (1) with a guide structure (10) defining a longitudinal axis (A1); a hook (2) detachably attached to the carrier piece (1); a spindle (3) movably guided in the guide structure (10) of the carrier piece (1) along the longitudinal axis (A1), which has an external thread (30); a spindle counterpart (4) movably mounted on the carrier piece (1) with an engagement structure (40) which is designed to engage in the external thread (30) of the spindle (3); and an elastic prestressing element (5) which prestresses the spindle counterpart (4) into an engagement position in which the engagement structure (40) is in engagement with the external thread (30) of the spindle (3), so that the spindle (3) can be displaced along the longitudinal axis (A1) by rotating about a spindle axis (A3) parallel to the longitudinal axis (A1), wherein the spindle counterpart (4) can be moved into a release position in which the engagement between the external thread (30) and the engagement structure (40) is released to such an extent that the spindle (3) can be displaced along the longitudinal axis (AI) by applying an axial force directed along the spindle axis (A3). Surgical instrument (100) according to claim 1, wherein the guide structure (10) is formed by a recess (10A) in the carrier piece (1). Surgical instrument (100) according to claim 1 or 2, wherein the guide structure (10) extends continuously between a first end (11) and a second end (12) of the carrier piece (1), wherein the spindle (3) is provided with a working end (31) can be moved beyond the second end (12) of the carrier piece (1), so that the fracture can be repositioned by the working end (31) of the spindle (3) and an end region (22) of the hook (2) facing away from the carrier (1), and wherein an actuating end (32) of the spindle (3) located opposite the working end (31) protrudes beyond the first end (11) of the carrier piece (1). Surgical instrument (100) according to claim 3, wherein the working end (31) of the spindle (3) can be moved into the guide structure (10) of the carrier piece (1). Surgical instrument (100) according to claim 4, wherein the working end (31) of the spindle (3) has a locking piece (34), in particular in the form of a ball, with which an attachment (35), in particular in the form of a plate, can be locked, wherein the guide structure (10) at the second end (12) of the carrier piece (1) preferably has a receptacle (12A) through which the working end (31) of the spindle (3) can be moved in the direction of the first end (11) of the carrier part (1), so that the attachment (35) locked to the locking piece (34) can be released, in particular removed, from the spindle (3) in the receptacle (12A). Surgical instrument (100) according to one of the preceding claims, wherein the spindle (3) has a first spindle part (3A) on which the external thread (30) is formed, and a second spindle part (3B) which is guided on the first spindle part (3A) in a linearly movable manner and is prestressed by a spring (33) against movement in the direction of the first spindle part (3B). Surgical instrument (100) according to one of the preceding claims, wherein the carrier piece (1) has a flat or substantially flat first surface (1a) and a flat or substantially flat second surface (1b). which is oriented opposite to the first surface (1a), wherein the longitudinal axis (AI ) runs parallel to the first and the second surface (1a, 1 b). Surgical instrument (100) according to one of the preceding claims, wherein the carrier piece (1) is designed as a handle. Surgical instrument (100) according to one of the preceding claims, wherein the spindle counterpart (4) is mounted on the carrier piece (1) in such a way that the engagement structure (40) is movable between the engagement position and the release position in a direction transverse to the longitudinal axis (AI ). Surgical instrument (100) according to one of the preceding claims, wherein the engagement structure (40) is formed at a first end (41) of the spindle counterpart (4) and a second end (42) of the spindle counterpart (4) protrudes from the carrier piece (1) with respect to a transverse direction extending perpendicular to the longitudinal axis (AI). Surgical instrument (100) according to one of the preceding claims, wherein: the spindle counterpart (4) is mounted on the carrier piece (1) so as to be rotatable about an axis of rotation (A4) extending perpendicular to the longitudinal axis (A1); or the spindle counterpart (4) is mounted on the carrier piece (1) so as to be linearly displaceable in a linear guide extending transversely to the longitudinal axis (A1). Surgical instrument (100) according to claim 11, wherein the spindle counterpart (4) is mounted on the carrier piece (1) so as to be rotatable and the axis of rotation (A4) is between a first end (41) and a second end (42) of the spindle counterpart (4). Surgical instrument (100) according to one of the preceding claims, wherein the engagement structure (40) has a plurality of engagement elements (40A), in particular in the form of teeth or pins, which can be brought into engagement with the external thread (30). Surgical instrument (100) according to claim 13, wherein the engagement elements (40A) have at least one sliding surface which, with respect to the longitudinal axis (AI), faces a first end (11) of the carrier piece (1) and is inclined such that the external thread (30) of the spindle (3) slides along the sliding surface when an axial force is applied along the spindle axis (A3) from the first end (11) in the direction of a second end (12) of the carrier piece (1), so that the engagement structure (40) is moved from its engagement position to its release position. Surgical instrument (100) according to one of the preceding claims, wherein the carrier piece (1) has a holder (14) with a receiving gap (14A) and a linearly movable locking bolt (17), wherein the hook (2) has a connecting piece (24) positioned in the receiving gap (14A) with a locking opening (27) into which the locking bolt (17) projects in a locking position in order to fix the hook (2) on the carrier piece (1). Surgical instrument (100) according to claim 15, wherein the connecting bolt (17) can be removed from the locking opening without tools by applying a tensile force. (27) of the connecting piece (24) of the hook (2) so that the hook (2) can be removed from the carrier piece (1). Surgical instrument (100) according to claim 15 or 16, wherein the holder (14) has a first block (15) with a passage (15A) in which the locking bolt (17) is guided, and a second block (16) spaced from the first block (15) by the receiving gap (14A), wherein the locking bolt (17) has a head (17A) located outside the receiving gap (14A) for applying the tensile force. Surgical instrument (100) according to claim 17, wherein the locking bolt (17) in the locking position and in a retracted position in which the locking bolt (17) is retracted from the receiving gap (14A) is each positively secured to the first block (15) against falling out of the passage (15A). Surgical instrument (100) according to one of claims 15 to 18, wherein the holder (14) and the connecting piece (24) are designed such that the connecting piece (24) can be fixed to the holder (14) in several rotational positions with respect to a central axis of the locking bolt (17). Surgical instrument (100) according to one of the preceding claims, additionally comprising: an actuating piece (36) for applying a torque to the spindle (3); and a torque limiter (7) which couples the actuating piece (36) to the spindle (3) and is designed to allow a relative rotation between the spindle (3) and the actuating piece (36) when the The torque applied to the actuating piece (36) exceeds a predetermined threshold value.