WO2015049558A2

WO2015049558A2 - Reposition forceps

Info

Publication number: WO2015049558A2
Application number: PCT/IB2014/001692
Authority: WO
Inventors: Daniel REISINGER; Severin REISINGER
Original assignee: Redam-Instrumente Gmbh
Priority date: 2013-09-03
Filing date: 2014-09-03
Publication date: 2015-04-09
Also published as: WO2015049558A3; CH708407B1

Abstract

The invention relates to a reposition forceps (100) with at least one first, upper branch (1) and at least one second, lower branch (2), having the first, upper branch (1) and the second, lower branch (2) hinged in a common pivot point (3); the first, upper branch (1) comprising a rigid, first upper forceps arm (4), a first handle piece (5) and a first, upper instrument tip (10) with a target sleeve (11); and the second, lower branch (2) comprising a rigid, second lower forceps arm (7), a second handle piece (8) and a second, lower instrument tip (15) with a target spike (16); and the reposition forceps (100) comprising at least one spring (6, 9); and a stroke (H) of the instrument tips (10, 15) is carried out by an actuation pressure (D₁) on the handle pieces (5, 8) against a spring force (F₁-F₂) of the spring (6, 9).

Description

4 001692

1

Reposition Forceps

[001] The present invention relates to a medical

instrument, as it is used for example in the conduct of surgery in which bones (e.g. finger, hand or foot bones) need to be repositioned, for example after a position displacing oblique fracture. For the implementation of such so-called open

repositions exist already reposition clamps and reposition pliers used for the removal of the defective position of the bone in line with an operation by means of osteosynthetic implants (screws, nails, plates, wires, amongst others) .

[002] These reposition clamps and reposition pliers typically have arresting locks or so-called raster detents, in the form of single latching clamps or barb-shaped interlocking single teeth or counter-mounted toothed racks. However, the functionality of such arresting locks or raster detents is not optimal suitable for very precise and fine repositioning, because the branches of an instrument equipped with such a locking mechanism, typically have to be compressed beyond the optimal closure point, in order to loosen again up to the effective locked state, when released- The closure of such reposition instruments results, depending on the size of the toothing, in larger or smaller steps, but is not continuously.

[003] In the case of repositioning, this optimal closure point results, when setting the repositioning clamp or

repositioning pliers, on one hand from a not too high

compressive stress on the broken or slivered bone fragments, so that no further damage to the bone fragments can occur by setting the branch tips- On the oth hand, the repositioning instrument should sit securely and should not move or loosen when applying the osteosynthetic implants (for example, when drilling a hole for the insertion of a irschner wire) . [004] Furthermore, known reposition instruments generally have a target sleeve or targeting aid, by which means a drill or directly the Kirschner wire can be set guidedly into the bone fragments. A disadvantage of these known reposition instruments however is that the surgeon does not get any precise

information, where exactly in the bone fragment the drill tip or Kirschner wire tip will be located on the opposite side of the target sleeve or where exactly it will exit.

[005] A further disadvantage of known reposition clamps and reposition pliers is that the branch tips or the instrument generally have or has too large dimensions to meet the sometimes very confined space available at small and delicate hand bones.

[006] Another disadvantage may be at known reposition clamps and reposition pliers, that if no scaling is provided, or only one representing perhaps an opening degree of the

instrument, but not representing at the same time for example exactly the depth of a set bore, the surgeon is forced to repeated and time consuming remeasuring.

[007] The problem or the object of the present invention is to provide, while avoiding the above-men ioned disadvantages, a precise and reproducible continuously adjustable reposition forceps, which is furthermore particularly well suited for the constricted space available at repositioning of hand bones, and is generally optimized in its properties and its application.

[008] The solution of the problem consists according to the invention in a first instance in the arrangement of two forceps parts or forceps arms, which are preferably hinged to in a common pivot point. Further, a reposition forceps according to the invention comprises at least one spring that acts cn the forceps arms with an opening pressure. Thus a reversal of the principle of operation of known reposition clamps or reposition pliers is effected insofar, as that a pressure builds up in the reposition instrument not until upon compression of the bone fragments, but due to the at least one spring, already the free operation of a reposition forceps according to the invention is carried out against the spring tension.

[009] The forceps arms or forceps parts themselves are preferably designed rigid. A basic version of a reposition forceps according to the invention thus comprises a first branch which is completely rigid from the instrument tip to pivot point and a second, flexible branch, which comprises in turn the rigid forceps arm and the at least one spring. The spring of the at least one spring-biased branch, which is articulated by means of this in the pivot point, is preferably a leaf spring.

[0010] As other spring types or spring assemblies come for example spring clips into consideration, disposed between the branches or the forceps arms, but basically also single or double volute springs or coil springs. Also in consideration comes a spring similar as at Feilchenfeld forceps, i.e. a fabrication of the forceps arms of bent spring steel or a fabrication of both forceps arms including the pivot point of a single-pieced, bent spring steel.

[0011] Since it is a medical instrument, for the benefit of the best possible cleaning or sterilization, it is preferred to avoid inaccessible areas like small cracks and inside surfaces; simple designs are preferred, for example, one utilizing a leaf spring connection between the rigid forceps arm and the common pivot point. This connection may be welded, screwed, riveted, soldered or glued together.

[0012] In a preferred embodiment of a reposition forceps according to the invention, each of the two rigid forceps arms are symmetrically attached with a leaf spring, in the common pivot point and form in this manner two flexible branches. But it would be also feasible to realize a reposition forceps according to the invention with two rigid forceps arms that are connected in a common pivot point and pressed apart by a spring clip arrangement.

[0013] Furthermore, it is preferred that a reposition forceps according to the invention comprises at least one stroke limitation, continuously adjustable, in at least one direction of stroke- This can be achieved by means of an either straight or curved bar, or of a straight or curved rod, at which a clamp stop is continuously shiftable. However, a stroke limitation in the form of a threaded rod is preferred, to which a nut is continuously rotatable.

[0014] With one end, the threaded rod is preferably located at the internal side of a branch, preferably riveted and/or welded and/or soldered, and furthermore preferably guided by an elongated guide slot of the other branch.

[0015] At the other end of the threaded rod it is preferred to install a limrter pin that prevents, on one hand, an accidentally complete unscrewing of the adjusting nut, and, on the other hand - coinciding with the maximum opening of the forceps - it represents a maximum value of at least one scale, which is preferably displayed on the threaded rod. This at least one scale can show digits or colors, or both, and preferably coinciding with the opening stroke of a reposition forceps according to the invention, in the sense, that the scale shows the maximum depth with which a drill or a Kirschner wire is insertable between the branch tips. To be more specific, the closed position corresponds to the zero value on the scale, and a particular opening stroke o£ the reposition forceps is preferably represented in millimeters as the distance between the instrument tips or rather as the combined thickness of the bone fragments. In this way, the operator obtains the

information that, for example, when 15 mm value is displayed on the scale, a 10 mm long screw would be indicated- Then, he may use for boring, a drill bit with a corresponding graduation indicating the offset by the length of the target sleeve and the drilling sleeve, when the drill bit has already penetrated 10 mm into the bone material.

[0016] The threaded rod can have, for the scale or scales, one or more flattened longitudinal surfaces, preferably aligned perpendicular to a longitudinal axis of the reposition forceps. Alternatively or in addition, the threaded rod, with or without a scale, may also be flattened along the sides that can come into contact with the edges of the elongated guide slot- This can be useful at a reposition forceps according to the

invention, when for example, an entanglement occurs in the closed position, due to the non-parallelism of the bone fragment top and bottom. In this way, the possibility is eliminated for sure that the upper branch gets caught with the elongated guide slot in the threads of the threaded rod.

[0017] The threaded rod preferably has a limiting stop at its lower end, riveted with the lower branch. This stop is setting the maximum closure of a reposition forceps according to the invention, by making full contact with the edges of the elongated guide slot. This stop is preferably dimensioned in such manner, that the tips of the instrument cannot converge and are thus protected.

[0018] The adjusting nut preferably forms a cone-shaped extension that stays in contact with the upper or outer edges of the elongated guide slot, due to the spring-biased opening pressure of the forceps arms. The inner threaded hole has referably no chamfer, in order to yield a good reading precision on the scale- The adjusting nut is preferably serrated, preferably at its maximum outside diameter. [0019] The adjusting nut and the threaded rod preferably have a thread with a pitch in a range between 0.1 and 0.5 mm. preferably of 0.25 mm, to wit 4 turns of the adjustment nut generate an axial movement of the adjusting nut of 1 mm along a longitudinal axis of the threaded rod. This is a pitch val e, which guarantees a good adjustment at good self-locking potential at the same time, even also at spherical or rolled thread. The latter are preferred because of their smooth surfaces for reasons of good cleaning and sterilization.

[0020] It would basically be possible to provide the threads of the adjusting nut with such a play, that the threaded rod could be formed in a slight bend, of course, under maintenance of the pitch and the required free movement and self-locking.

[0021] A central portion of a reposition forceps according to the invention, which preferably extends between the leaf springs and the threaded rod, further comprises preferably thickened handle pieces, which are preferably arranged

approximately in the center of the part or preferably

approximately in the center of mass of a reposition forceps according to the invention, and placed respectively opposite, in both branches. These thickened handles serve for improved handling and haptic, but on the other hand, for an optimization of the weight and balance of a reposition forceps according to the invention .

[0022] The compression of the thickened handles results in a closing movement, which is composed, in particular when using approximately equal strong leaf springs at each branch of the instrument, in a first movement of the threaded rod through the elongated guide slot and a second, opposite movement of the elongared guide hole, versus the threaded rod. As already mentioned at the beginning, it would also be possible, as an option, to design one branch completely rigid, i.e. without spring. Then the closing movement would only consist of an arcuated movement of the flexible branch against the rigid branch .

[0023] The threaded rod or also a screw with head may be mounted at will, on the one branch or the other.

[0024] The branch which is in the application case rather the upper one, is that one, which is in the case of a reposition forceps according to the invention with only one spring-biased branch, preferably also the spring-biased one. Furthermore, a target sleeve is arranged at the instrument tip of this upper branch approximately in a right angle to the longitudinal axis of the reposition forceps or the longitudinal axis of the upper branch. This target sleeve is preferably cut diagonally, so that it forms a beaked tip. Moreover, the tip is preferably hollow, for receiving a drill sleeve or drill aid, which in turn is preferably designed in different sizes and with different bore diameters, as a set available and insertable in the target sleeve as required,

[0025] The insertion of the drill sleeve or drill aid in the target sleeve is effected preferably by overcoming a slight resistance, for example, by pressing a small circularly outer diameter thickening into a corresponding internal groove. The inner diameter of the target sleeve and the outer diameter of the drill sleeve or drill aid can be optionally designed in a form- fitting polygonal correspondence, in this way, the drill sleeve or drill aid would be arranged in the target sleeve in a secured manner against falling out or twisting. The drill sleeve is preferably at its maximum outer diameter serrated.

[0026] The opposite, lower branch forms preferably at its instrument tip a target spike. The bone fragments to be repositioned are grasped with the tip of the target sleeve and the target spike. The target spike preferably has a length in a range of 2 to 20 mm and is preferably 10 mm. An advantage of this relative long target spike is that it can penetrate through the soft tissue, if the exposure of only one side of the bone or bone fragments suffices.

[0027] The tip of the target sleeve and the target spike are at a reposition forceps according to the invention preferably offsetted, what means, that the target spike is proximally interposed and corresponds approximately to the drilling axis, which is defined by the drill sleeve. In this way, the surgeon obtains the precise information, where on the opposite side of the bone fragment the drill or the Kirschner wire will be placed, or where it will leak, when drilled through. In this latter situation, a hole or a long hole in the lower branch in the vicinity of the target spike can be helpful, in order to be able to come with the drill or Kirschner wire therethrough.

[0028] The target spike and the target sleeve don't have to be equal in length and may be optionally arranged in an angle to the branches, which is smaller than right. This angle may lie in a range of 85 to 75 degrees and is preferably 80 degrees. This angle is preferably chosen so that the two instrument tips would impinge then nearly perpendicular to a bone fragment, when the reposition forceps is half open or when working with a

repositioning position which approximately corresponds to half the stroke of the reposition forceps.

[0029] The fixed connections between the single parts of a reposition forceps according to the invention are preferably welded or soldered, sanded and furthermore preferably surface treated. As already mentioned, further types of joining techniques like screwing, riveting and/or adhesive bonding come also into consideration.

[0030] A reposition forceps according to the invention is preferably totally surface treated, preferably also

antibacterial nano-coated, for example with nano-silver, or plasma-coated using a new developed process by the Fraunhofer Institute for Manufacturing Technology and Applied Materials Research IFAM in Bremen/Germany and the Plasmatreat GmbH in Steinhagen/Germany .

[0031] Also into consideration come so-called lotus blossom surfaces, but also a nano-coating according to the process of the company nanopool GmbH in HUlzweiler-Schvialbach/Germany .

[0032] Further into consideration coming surface treatments relate to coatings, which give a dark-matte color to the entire reposition forceps, so that there is no reflection under the illumination of operation lights or of a microscope. This is preferably achieved as the surfaces of a reposition forcepa according to the invention are at least partially sandblasted or coated with a black ceramic. Furthermore, color-coding comes into consideration, but also surface treatments that counteract premature wear of the reposition forceps or the instrument tips. As latter treatment comes in particular the so-called diamond coating into consideration.

[0033] The handle pieces of a reposition forceps according to the invention may also be flat or round grips, which have preferably a width or a diameter in a range of 5-35 mm and preferably approx- 15 mm- The handle pieces may have a ribbing, such as a so-called pyramid ribbing for improved contact in the hand of the operator. Furthermore preferred is however a so- called golf ball design, which is characterized in oval curved deepenings in the surface in approximately 1-10 mm in diameter, preferably in a length of about 4 mm and a width of about 3 mm. This golf ball design gives best results in terms of cleaning or sterilization, but also with respect to handling and feel.

[0034] A reposition forceps according to the invention is preferably made of titanium or one or more titanium alloys, but also other materials come into consideration, like stainless steel alloys or a composite of these materials.

[0035] The springs may be welded to the grip section surface, screwed on, riveted to or glued on, but however, also possible is an open-sided or a closed cut-out in the grip piece, in which the spring is insertable bayonet-like, before welding or soldering.

[0036] By such means of a cutout, it is basically possible to provide a reposition forceps according to the invention, with interchangeable tips. This means that any arbitrary instrument combination can be selected, not only before welding, soldering, screwing, riveting or gluing. But, disregarding the fixed connection, even also during subsequent use, the instrument tips can also remain exchangeable.

[0037] Optionally, the stroke motion of a reposition forceps according to the invention, may be limited by a stop bolt, mounted between the forceps arms. This stop bolt can be foreseen instead of, or in addition to the already described stopper on the threaded rod.

[0038] In a preferred embodiment of a reposition forceps according to the invention, the stroke motion is composed of nearly simultaneous stroke motions of a first and a second branch, i.e. both branches are due approximately same spring strengths to the same extent flexible- However, in the scope of the disclosure of the present application, lie also embodiments of reposition forceps according to the invention with a rigid and a flexible branch, as well as two rigid branches that are connected with a curved spring steel or with a joint.

[0039] Furthermore are within the scope of the disclosure of the present application such embodiments of a reposition forceps according to the invention, in which a function reversal of the instrument is accomplished- Such a reposition forceps according to the invention with reversed branches opens when pressing the handle pieces and closes with spring pressure when released- In this way, in certain applications it may be advantageous to be able to set the reposition forceps with only one hand, then release it and it still remains in the already set position. Subsequently, an optional stroke limitation or fixation can be set or screwed in place, in addition to the already holding spring force.

[0040] The disclosed different embodiments of a reposition forceps according to the invention are, related to the not basic functional relevant features, arbitrarily combinable with each other. So are for example all described embodiments combinable with the described spring types, also within one single reposition forceps, as well as are combinable with each other the embodiments with or without stroke limitation, with or without scale, with or without thickened handle pieces, with or without stop, with or without deflection, with or without surface treatment, coloring, matting or diamond coating with the described different types of grips, as well as regarding the disclosed materials or composites thereof.

[0041] The present application discloses a method for repositioning with a such as previously disclosed reposition forceps, with the following basic steps:

a) - Setting of the reposition forceps by grasping the bone fragments to be repositioned between the target sleeve and the target spike by applying an actuation pressure to the handle pieces

b) - closing of the continuously adjustable stroke limitation by twisting of the adjusting nut until its cone-like extension stops at the edges of the elongated guide slot in the first, upper branch;

c) - inserting into the target sleeve, of a drill sleeve, selected out of a set;

d) - drilling or directly setting of a screw or a Kirschner wire through a guide bore into the drill sleeve;

e) - removing of the drill sleeve;

f) - loosening f the adjusting nut;

g) - removing of the reposition forceps.

[0042] A reposition forceps according to the invention brings the following advantages:

- It, is particularly well suited, due to the small dimensions and configuration as forceps, for fine repositioning of small and near together located bones.

- It works spring force-based with a continuous stroke limitation .

- When grasping the bone fragments, exactly only that pressure is exerted, which is necessary.

- It provides a secure hub in the set state .

- The surgeon obtains the exact information where the drill or the Kirschner wire is placed in the bone fragment, or where it will exit.

- The scale displays the drill depth, a remeasurement is not required .

- The instrument tips are protected against contact by a stop.

- By limiting the stroke with a fine pitch, it offers a good adjustability.

- The drill sleeve is secured against falling out and/or twisting .

- The angles of the instrument tips to the branches are optimized.

- The handling of the reposition forceps is overall optimized.

- The surfaces are well sterilizable .

- The surfaces are free of reflection.

- If provided, the instrument tips are interchangeable.

- If a reversal of branches is provided, for certain

applications, reposition forceps instrument may be better suited. [0043] Further or advantageous embodiments of a reposition forceps according to the invention are subject of the dependent claims .

[0044] The list of reference numerals is part of the disclosure .

[0045] By means of figures, the invention is symbolically and exemplarily exemplified in more detail. The figures are described coherently and comprehensively. They are schematic and exemplary representations and are not true to scale, also not in the relation of the individual components to each other.

Identical reference numerals denote the same component, reference numerals having different indices indicate

functionally identical or similar components.

[0046] It shows thereby

Fig. 1 a schematic and perspective view of an exemplary first embodiment of a reposition forceps according to the invention, in opened position;

Fig. 2 a schematic representation of the embodiment of a reposition forceps according to the invention shown in Fig. 1, also perspective view, but in closed position;

Fig. 3 a schematic and perspective view of the embodiment of a reposition forceps according to the invention shown in the figures 1 and 2, in compressed position and in a view from oblique below;

Fig. 4 a schematic and perspective view of a blank of a lower branch of a reposition forceps according to the invention from the previous figures;

Fig. S a schematic and perspective view of a blank of a upper branch of a reposition forceps according to the invention from the figures 1-3;

Figure 6 a schematic view of a threaded rod of a stroke limitation of a reposition forceps according to the invention from the figures 1-3; Fig. Ί a schematic view of an adjusting nut of a stroke limitation of a reposition forceps according to the invention from the figures 1-3;

Fig. 8 a schematic view of a target sleeve of the reposition forceps from the figures 1-3;

Fig. 9 a schematic side view of a second embodiment of a further reposition forceps according to the invention with a pivot point for the branches in the form of a curved spring; Fig. 10 a schematic side view of a third embodiment of a further reposition forceps according to the invention with a pivot point for the branches, in the form of a joint and a spring clip assembly and

Fig- 11 a schematic side view of a fourth embodiment of a further reposition forceps according to the invention with a deflection of the branches.

[0047] in Fig. 1, an exemplary first embodiment of a reposition forceps 100 is shown schematically, which has a longitudinal direction along a longitudinal axis LA, with a first, upper branch 1 and a second, lower branch 2, connected in each case in a common pivot point 3 to each other, preferably welded or soldered. The first, upper branch 1 comprises a first, upper forceps arm 4, a first, thickened handle piece 5, and a first leaf spring 6. The second, lower branch 2 comprises a second, lower forceps arm 7, a second, thickened handle piece 8, and a second leaf spring 9.

[0048] The first, upper branch 1 of the reposition forceps

100 forms as a first, upper instrument tip 10 a target sleeve 11, which is approximately perpendicular to the longitudinal orientation of the first upper forceps arm 4, along a drilling axis BA and inserted in a drill sleeve 12. in this view one can see of the drill sleeve 12 only a serrated head 13 and a guide bore 14, through which a screw or a irschner wire is set- [0049] The second, lower branch 2 of the reposition forceps

100 forms as second , lower instrument tip 15 and a target spike 16, which is also disposed approximately perpendicular to the longitudinal orientation of the second, lower forceps arm 7.

[0050] The reposition forceps 100 further comprises a stroke limitation 200, which in turn, comprises a threaded rod 17, which is disposed in the shown position along an axis Y. The threaded rod 17 is fixed with a lower end to the second, lower forceps arm 7 and forms in a lower part a thickened stop 18.

[0051] At an upper end of the threaded rod 17, an adjusting nut 19 is screwed onto a thread 20. The adjusting nut 19 has a serrated head 21, and a cone-shaped extension 22 , which serves as opening stop 23 for the forceps arm 4 and respectively for the edges of an elongated guide slot 24, against a first spring force Fi of the leaf spring 6 and against a hereto added, second spring force F₂ of the leaf spring 9- [0052] The threaded rod 17 further ha3 a flattened

longitudinal surface 25, to which a scale 26 is applied. At the upper end of the threaded rod 17, a limiter pin 27 is installed.

[0053] An actuation pressure Di on the thickened handle pieces 5 and 8 causes a stroke motion H of the instrument tips 10 and 15. The maximum stroke motion H ranges from reaching the end of the lower edges of Che elongated guide slot 24 on the stop 18, what then would correspond a closed minimal position or minimum opening Ρ_{α η} of the reposition forceps 100, up to reaching the upper edges of the elongated guide slot 24 at the cone-shaped extension 22 of the adjusting nut 19, whereupon the adjusting nut 19 as shown contacts the limiter pin 27, what in turn corresponds to a shown maximum open position or maximum opening P_max. [ 0054 ] Furthermore, in the shown view, it can be seen that on the upper side of the first, thickened handle piece 5 , oval depressions 28 are disposed, resulting in a so-called golf ball design.

[0055] In the Fig. 2, the reposition forceps 100 from Fig. 1 is shown again in a perspective overall view, taut this time however, corresponding to the maximal closed minimum position or minimum opening P_Mn. This means, that the adjusting nut 19 is screwed maximally down on the threaded rod 17, namely so, that the first, upper forceps arm 4 respectively the lower edges of the elongated guide slot 24 contacts the stop 18. The first, upper forceps arm 4 and the second, lower forceps arm 7 are no longer movable. Furthermore it can be seen, that for their protection, even in this position, the first, upper instrument tip 10 or the target sleeve 11 and the second, lower instrument tip 15 or the target spike 16 do not touch.

[0056] In the Fig. 3, the reposition forceps 100 from the figures 1 and 2 is illustrated again in a perspective overall view, this time however from oblique below. One needs to visualize, that a hand actuation pressure D_¾ is exerted manually against the spring forces Fi and F_z, and thus, although the adjusting nut 19 is not in contact with the first, upper forceps arm 4, the reposition forceps 100 is in the complete closed minimum position P_{m n}. This is well recognizable in the fact that the lower edges of the elongated guide hole 24 touch the stop 18.

[0057] Furthermore, it is well recognizable that the threaded rod 17 is inserted into a mounting bore 29 of the second, lower branch 2, preferably riveted and welded or soldered, and that the second, thickened handle piece 8 shows also the so-called golf ball design resulting in oval deepenings 28a, like the top side of the first, thickened handle piece 5, too .

[0058] Furthermore, the drill sleeve 12 is shown exploded.

Thereby one may see, that the serrated head 13 forms below centric an insertion sleeve 30, through which passes the guide bore 14, also centric. By means of this insertion sleeve 30, the drill sleeve 12 is insertable into a receiving bore 32 of the target sleeve 11. Optionally, the drill sleeve 12 can be secured against radial rotation about the drilling axis BA, by forming the insertion sleeve 30 and the receiving bore 32 not round, but for example tetragonal.

[0059] Furthermore, it is in this Fig. 3 well recognizable, that the second, lower instrument tip 15 of the second, lower branch 2 and the target spike 16 of the second, lower forceps arm 7 are arranged in an offset V to the first, upper instrument tip 10 of the first, upper branch 1, respectively proximally offsetted to a target tip 31 of the target sleeve 11 of the first, upper forceps arm 4. The target spike 16 rather

corresponds to the drilling axis BA and gives the surgeon thus a good and accurate indication, looking at the underside of the bone fragments to be repositioned, where the bore is located.

[0060] In the Fig. 4, the second, lower branch 2 of the reposition forceps 100 from the previous figures 1-3 is shown separately. The mounting bore 29 is now well identifiable, as well as a fastener thickening 33, which serves for the welding or soldering with the other branch of the reposition forceps.

[0061] The Fig. 5 shows the first, upper branch 1 of the reposition forceps 100 from the previous figures 1-3 separately. One can see the elongated guide slot 24, a fastener thickening 33a corresponding to the fastener thickening 33 of the branch 2 from the Fig. 4, and opposed a mounting bore 34, into which the target sleeve 11 is inserted. [0062] In the Fig. 6, the threaded rod 17 is shown, with the scale 26 on the flattened longitudinal surface 25. It may be disposed also several flattened longitudinal surfaces, with or without scales.

[0063] The Fig. 7 shows the adjustment nut 19, with its cone-shaped extension 22 and a centrally arranged threaded bore 35. [0064] In the Fig. 8, the target sleeve 11 is shown separately and enlarged, with the target tip 31 and the through- going receiving bore 32.

[0065] The Fig. 9 shows a second embodiment of a further reposition forceps 100a, which differs from the reposition forceps 100 from the figure 1-3, in that a curved spring steel 36 forms a common pivot point 3a. A first, upper branch la and a second, lower branch 2a are respectively pushed apart with a spring force F3 respectively F₄.

[0066] An actuation pressure D₂ that acts on both sides of handle pieces 5a and 8a, is in the illustrated position of the reposition forceps 100a smaller to equal as the spring forces F₃ and F₄, and thus the upper edges of an elongated guide slot 24a are in contact with a cone-shaped extension 22a of an adjusting nut 19a. Due to the fact that the adjusting nut 19a is in a maximal upper position at a limiter pin 27a, the Fig. 9 shows a maximally opened maximum position Ρ_ω¾ι of the reposition forceps 100a.

[0067] There are no further differences to the reposition forceps 100 illustrated in the figures 1-3, so that the known parts have the same reference numerals, but upgraded to a higher index a or by one digit. [0068] In the Fig. 10 is shown, analogue to the Fig. 9, a further embodiment of a reposition forceps 100b, likewise in a maximally opened maximum position P^_J- This reposition forceps 100b has a common pivot point 3b in form of a joint 37, in which a complete rigid first, upper branch lb and an also complete rigid second, lower branch 2b are hinged to, and which in turn open due to spring forces F₅ and F& of a spring clip assembly 38. This spring clip assembly 38 may comprise two spring clips 39a and 39b, but also only one single S-shaped.

[0069] The Fig. 11 shows a fourth embodiment of a further reposition forceps 100c, which is characterized basically by a deflection 40, of a first, upper branch lc and a second, lower branch 2c. Both of these branches lc and 2c are respectively hinged to by means of a leaf spring 6a and 9a in a common pivot point 3c, which is optionally designed as a rounded handle 41.

[0070] The spring forces F and F₈ of the leaf springs 6a and

9a press a first, upper forceps arm 4c and a second, lower forceps arm 7c into the illustrated, closed minimum position Pnun3_/ as long as an actuation pressure D₄ is not higher than spring forces F₇ and Fj. With the reposition forceps 100c instrument tips 15c and 10c are opened by the actuation pressure E>₄, applied respectively on the handles 5c and 8c, and by releasing, the bone fragments to be repositioned are grasped.

This release can be achieved completely by removing the hands, because the spring forces F₇ and Fs are preferably laid-out in such corresponding strong manner, that the instrument tips 15c and 10c remain in the set position on the bone fragments. Thus stand the surgeon both hands at his disposal, for the subsequent securing with an adjusting nut 19c, without having to apply any further actuation pressure D₄. This can be for certain

applications perhaps advantageous. List of Reference Numerals

1, la-lc - first, upper branch

2, 2a-2c - second, lower branch

3, 3a-3c - common pivot point

4, 4a-4c - first, upper forceps arm

5, 5a-5c - first, thickened handle piece

6, 6a - first leaf spring

7, 7a-7c - second, lower forceps arm

8, 8a-8c - second, thickened handle piece

9, 9a - second leaf spring

10, lOa-lOc - first, upper instrument tip

11, lla-llc - target sleeve

12, 12a-12c - drill sleeve

13, I3a-I3c - serrated head

14 - guide bore

15, 15a-15c - second, lower instrument tip

16, 16a-16c - target spike

17, 17a-17c - threaded rod

18, 18a-18c - limiting stop

19, 19a-19c - adjusting nut

20, 20a-20c - thread

21, 21a-21c - serrated head

22, 22a-22c - cone-shaped extension

23 - opening stop

24, 24a-24c - elongated guide slot

25 - flattened longitudinal surface

26 - scale

27, 27a-27c - limiter pin

28, 28a - oval deepening

29 - mounting bore

30, 30a - insertion sleeve

31 - target tip

32 - receiving bore

33, 33a - fastener thickening

34 - mounting bore 35 - threaded bore

36 - curved spring steel

37 - joint

38 - spring clip assembly

39a, 39b - spring clip

40 - deflection

41 - rounded handle

100, lOOa-lOOc - reposition forceps

200, 200a-200c - stroke limiter

BA, BA1-BA₃ drilling axis

Di~Di - actuation pressure

Fj-Fs - spring force

H, H₁-H3 - stroke

LA, LAj.-L¾₅ - longitudinal axis

P_fftax, Pmaxi-Prcax3 maximum position, maximum opening Pmin _f Pmiru- Pmin- ~ minimum position, minimum openin^> V - offset

Y, Yj- 3 - axis, ordinate

Claims

Patent Claims

1. Reposition forceps (100, lOOa-lOOc) with at least one first, upper branch (1, la-lc) and at least one second, lower branch (2, 2a-2c) , having the first, upper branch (1, la-lc) and the second, lower branch (2, 2a-2c) hinged in a common pivot point (3, 3a 3c) ; the first, upper branch (1, la-lc) comprising a rigid, first upper forceps arm (4, 4a-4c) , a first handle piece (5, 5a-5c) and a first, upper instrument tip (10, lOa-lOc) with a target sleeve (11, lla-llc) ; and the second, lower branch (2, 2a -2c) comprising a rigid, second lower forceps arm (7, 7a-7c) , a second handle piece (8, 8a-8c) and a second, lower instrument tip (15, 15a-15c) with a target spike (16, 16a-16c) ; and the reposition forceps (100, lOOa-lOOc) . comprising at least one spring (6, 6a, 9, 9a, 36, 39a, 39b); and a stroke (H, Hj-H₃) of the instrument tips (10, lOa-lOc 15, 15a-15c) is carried out by an actuation pressure (Dj.-D₄) on the handle pieces (5, 5a~5c, 8/ 8a-8c) against a spring force (F]_.-F₈) of the spring (6, 6a, 9, 9a, 36 , 39a, 39b) .

2. Reposition forceps (100, lOOa-lOOc) according to claim 1, characterized in that the reposition forceps (100, lOOa-lOOc) comprises a continuously adjustable stroke limitation (200, 200a-200c) .

3. Reposition forceps (100, lOOa-lOOc) according to claim 2, characterized in that the stroke limitation (200, 200a-200c) comprises a scale (26) .

4. Reposition forceps (100, lOOa-lOOc) according to one of the preceding claims 2 or 3, characterized in that the stroke limitation (200, 200a-200c) comprises a threaded rod (17, 17a- 17c) with at least one flattened longitudinal surface (25); with a limiting stop (18, 18a-l8c) ; with a limiter pin (27, 27a-27c) and an adjusting nut (19, 19a-19c) with a cone-shaped extension (22, 22a-22c) , and that the threaded rod (17, I7a-17c) is fixed by means of a mounting bore (29) at the second, lower forceps arm (7, 7a-7c) and is guided through an elongated guide slot (24, 24a-24c) in the first, upper forceps arm (4, 4a-4c) .

5. Reposition forceps (100, lOOa-lOOc) according to one of the preceding claims, characterized in that the target sleeve (11, lla-llc) has a receiving bore (32) in which a drill sleeve (12, 12a-12c) is insertable.

6. Reposition forceps (100, lOOa-lOOc) according to claim 5, characterized in that the target sleeve (11, lla-llc) and the drill sleeve (12, 12a-12c) comprise a security against falling out and twisting of the drill sleeve (12, 12a-12c) .

7. Reposition forceps (100, lOOa-lOOc) according to one of the preceding claims, characterized in that the target spike (16, 16a-16c) is arranged proximally offsetted to a target tip (31) of the target sleeve (11, lla-llc) .

8. Reposition forceps (100, lOOa-lOOc) according to one of the preceding claims, characterized in that the target sleeve (11, lla-llc), related to the first, upper forceps arm (4, 4a-4c) and the target spike (16, I6a-16c) , related to the second, lower forceps arm (7, 7a-7c) , are arranged in an angle, which lies in a range of 85 to 75 degrees and is preferably 80 degrees.

9. Reposition forceps (100, lOOa-lOOc) according to one of the preceding claims, characterized in that the surfaces of the reposition forceps (1O0, lOOa-lOOc) are nano- and/or plasma- coated .

10. Reposition forceps (100, lOOa-lOOc) according to one of the preceding claims, characterized in that the handle pieces (5, 5a-5c, 8, 8a-8c) comprise oval deepenings (28, 28a), arranged in rows .

11. Reposition forceps (lOOb) according to one of the preceding Claims, characterized in that the reposition forceps (100b) comprises a joint (37) in which the branches (lb, 2b) are hinged to.

12- Re osition forceps (100c) according to one of the preceding claims, characterized in that the reposition forceps (100c) comprises a deflection (40) of the branches (lc, 2c) .

13- Process for the application of the reposition forceps (100, lOOa-lOOc) according to one of the preceding claims 1-12,

characterized in that the following process steps are performed: a) - Setting of the reposition forceps (100, lOOa-lOOc) by grasping the bone fragments to be repositioned between the target sleeve (11, lla-llc) and the target spike (16, 16a-16c) by applying an actuation pressure (Di-D«) to the handle pieces (5, 5a-5c, 8, 8a-8c) ;

b) - closing of the continuously adjustable stroke limitation (200, 200a-200c) by twisting of the adjusting nut (19, 19a-19c) until its cone-like extension (22, 22a-22c) stops at the edges of the elongated guide slot (24, 24a-24c) in the first, upper branch (1, la-lc) ;

c) - inserting into the target sleeve (11, lla-llc), of a drill sleeve (12, 12a-12c) , selected out of a set;

d) ~ drilling or directly setting of a screw or a Kirschner wire through a guide bore (14) in the drill sleeve (12, 12a~12c) ; e) - removing of the drill sleeve (12, 12a-12c) ;

f) - loosening of the adjusting nut (19, 19a-19c) ;

g) - removing of the reposition forceps (100, lOOa-lOOc) .