EP1675516A1

EP1675516A1 - System for the minimally invasive treatment of a bone fracture, especially of a proximal humeral or femoral fracture

Info

Publication number: EP1675516A1
Application number: EP04817195A
Authority: EP
Inventors: Georg Gradl
Original assignee: Intercus GmbH
Current assignee: Intercus GmbH
Priority date: 2003-10-18
Filing date: 2004-10-15
Publication date: 2006-07-05
Also published as: WO2005037117B1; US20070225714A1; WO2005037117A1; DE10348932B4; DE10348932A1; US7927333B2

Abstract

The invention relates to a system for the minimally invasive treatment of a bone (3) fracture, especially of a proximal humeral or femoral fracture. The inventive system comprises an osteosynthesis plate (1) having a supporting section (12) in the cortical substance and an additional fastening section (5) on the bone (3). A second linking section (20) of the guide element (4) and the shaft (18) of the fixing element (20) are configured as an axially displaceable anti-tilt slide bearing. The system comprises at least one anti-twist screw (28) in the supporting section (12) as a means for preventing the detached bone fragment from rotation.

Description

SYSTEM FOR THE MINIMALLY INVASIVE TREATMENT OF A FRACTURE OF A BONE, IN PARTICULAR A PROXIMUM HUMERUS OR FEMUR FRACTURE

description

The invention relates to a system for minimally invasive care of a fracture of a bone, in particular a proximal humeral or Fe fracture.

As is known, surgical therapy has a permanent place in the care of bone fractures. It is usually indicated when there is considerable dislocation of the fracture fragments, a malfunction of the fragments caused by the fracture cannot be remedied by reduction alone or in the case of multi-fragment fractures. In principle, priority is given to surgical methods with the least degree of soft tissue damage and the advantage of early postoperative movement therapy. Therefore, the importance of systems for minimally invasive care of bone fractures is increasing. However, suitable systems are not available for all of the various fractures that occur minimally invasive care available. In the case of the shoulder, access from the outside of the upper arm has also not been customary to date, since there is a risk of injury to the axillary nerve in known surgical techniques.

The use of plates and screws is one of the standard procedures for treating upper arm fractures that affect the head end of the humerus (also called the humerus). In the case of these fractures, also called proximal humeral fractures, the plates and screws are inserted in a conventional manner, that is to say not in a minimally invasive manner, over a sufficiently large skin incision, which is about 10 cm long in adults. To attach the plate to the humerus with the screws, the muscular membranes and muscles, but also the joint capsule of the shoulder joint must be severed. Fracture healing is satisfactory with this procedure. The large operative access is very stressful for the shoulder. Since the shoulder joint has very little bony guidance and a thick coat of musculature envelops the shoulder, the interventions in the soft tissue of the shoulder required for inserting the plates and screws are usually associated with considerable postoperative movement restrictions.

In order to avoid damage to the soft tissue, intramedullary bundle nailing has become known as a particularly gentle procedure for the treatment of proximal humeral fractures. Here, after opening the bone marrow cavity, thin nails in the medullary canal are made over a small skin incision, just above the elbow, up to the upper end of the humerus and over pushed the fracture site. However, this procedure is only suitable for a few very simple fracture types. In the case of fractures with several fragments, the nails travel through the open bone areas in the fracture area and interfere in the joint.

A system known as a "dynamic hip screw" has become known for the treatment of fractures which affect the hip-side end of the femur (also called the proximal femur fracture). This system is used to connect a bone fragment to the non-fractured part of the bone. The dynamic The hip screw system has a screw that is screwed into the bone fragment after a corresponding drill hole has been drilled in. The screw is dimensioned such that it is received over the entire length of the drill hole. The free end of this screw is secured using a plate The plate has at one end a tubular section arranged at an angle to the longitudinal axis of the plate, which is inserted into the borehole of the bone before the plate is attached to the bone, around the free end of the aforementioned Pick up and fix screw. The dynamic hip screw However, ben system cannot be used in a minimally invasive manner. It is also not suitable for the treatment of humeral fractures.

According to US Pat. No. 5,429,641, a system for minimally invasive treatment of a fracture of a bone is also known. Are inserted into a sleeve in the bones here, "long screws" via a connecting section. The system of "long ^screws" "is tip-resistant and axially displaceable slidably built up, but only during screwing into the bone. The disadvantage here is that after the screws have been set, it is a rigid, tension-type connection that prevents axial displacement after installation.

The present invention therefore has the task of specifying a system for minimally invasive care of bone fractures, by means of which high stability can be achieved in the area of the fracture and at the same time soft tissue is only damaged to a small extent.

This object is achieved by a system for minimally invasive treatment of a fracture of a bone, in particular a proximal humerus or femur fracture, comprising an osteosynthesis plate, which has a support section which can be positioned with a support surface on the bone adjacent to the fracture, and an attachment section Fixing the osteosynthesis plate to the bone has a fixing element for fixing in a fragment of the bone loosened by the fracture, and a guide element which can be fixed to the osteosynthesis plate via a first connecting section and which has a second connecting section for guiding the fixing element, the Support section of the osteosynthesis plate has at least a first recess and the fixation element and the guide element can be inserted into the bone through the first recess. This design makes it possible to minimally invasively stabilize fractures, in particular subcapital humerus and fire fractures, with an osteosynthesis plate and to hold the bone fragments in position relative to one another.

The osteosynthesis plate according to the invention can be inserted through a small incision, which is made in the subcapital humeral fracture below the humerus, to the bone and then pushed up along the bone, scraping the muscles, until the support section is adjacent to the fracture to be stabilized comes to lie. After the osteosynthesis plate has been fixed to the bone in this position by means of the fastening section, the fixation element can be inserted into the bone through the first recess through a further small skin incision and after a borehole has been drilled in the bone and fixed in the bone fragment detached by the fracture , The guide element, which is likewise inserted through the first recess, is connected via its first connecting section to the osteosynthesis plate and via its second connecting section to the fixation element, as a result of which it is guided in a manner that stabilizes the fracture. With the system according to the invention, even more complicated fractures can be treated in a minimally invasive manner without having to damage soft tissue to a greater extent. This is particularly advantageous in the case of proximal humerus fractures, since neither the muscles that support the shoulder nor the joint capsule are significantly affected. Accordingly, post-operative healing is accelerated. Restrictions on shoulder movement are significantly reduced. According to an advantageous embodiment of the invention, it is provided that the first recess in the support section and the guide element are designed such that a longitudinal axis of the guide element and a surface extending tangentially to the side of the osteosynthesis plate facing the bone form an angle between 50 ° and 70 °, include in particular between 55 ° and 65 °. An osteosynthesis plate designed in this way is particularly suitable for proximal humeral fractures.

Unwanted movements of the guide element are counteracted in that fastening means are provided on the osteosynthesis plate and / or the guide element, which hold the guide element axially fixed in both directions after insertion into the osteosynthesis plate.

Handling is simplified in that alignment means are provided, by means of which the rotational position of the guide element relative to the osteosynthesis plate can be set and / or controlled. This is particularly advantageous if an additional bone splinter fixation element is to be connected to the guide element, as will be explained in more detail below.

According to an advantageous embodiment, the fastening means comprise a groove formed in the first recess of the support section and a corresponding nose formed on the guide element which can be inserted into the groove. A stop for abutment against the nose is provided in the groove, which limits a rotational movement of the guide element. As a result, the rotational position of the guide element relative to the osteosynthesis plate can be set and / or checked.

Alternatively, the fastening means can comprise an external thread formed on the first connecting section of the guide element and an internal thread which can be brought into engagement and formed in the first recess.

Good guidance of the fixation element is achieved in that the second connecting section of the guide element is designed as a receptacle in which a shaft of the fixation element is received in a tilt-stable and axially displaceable manner. Due to the axial displaceability, shrinkage occurring at the bone gap during the healing process can be compensated for. Accordingly, the fixation element can also be referred to as a sliding fixation element or, in the case of a design of the fixation element, as a screw as a sliding screw.

According to one embodiment of the invention, the shaft of the fixation element has driver surfaces, by means of which the fixation element is held in the receptacle in a rotationally fixed manner. On the one hand, this enables the fixation element to be screwed into the bone fragment using a tool, and under certain circumstances also using the guide element. At the same time, this ensures that the guide element and fixation element are secured against rotation. Alternatively, the shaft of the fixation element can also be held rotatably in the receptacle. According to a particularly advantageous embodiment of the invention, a bone splinter fixing element is provided, which can be fixed in or on the guide element, in particular in a transverse bore provided therein. This design is particularly advantageous if, as is often the case, the fracture has resulted in three or even more bone fragments. Using the bone splinter fixation element, a further fragment of the bone can then be held on the osteosynthesis plate and the bone healing can thus be accelerated.

According to a development of this inventive concept, the transverse bore is arranged in the guide element such that a longitudinal axis of the elongated bone splinter fixing element and a longitudinal axis of the guide element enclose an angle between 60 ° and 100 °, in particular between 70 ° and 90 °. As a result, the system according to the invention is particularly suitable for humerus fractures in which the tubercle majus fragment has been separated.

This fragmented fragment can not only be held by the bone splinter fixation element, but pressure can also be exerted in the desired direction, which is advantageous for rapid bone formation.

Fixing a splintered bone fragment or splinter is easier if that

Bone splinter fixation element is designed as a screw which has a pressure body having claws. A further improvement is achieved in that means are provided to prevent rotation of the detached bone fragment. For this purpose, an anti-rotation screw having a head is preferably provided, which can be inserted into the detached bone fragment through at least one second recess in the support section.

Due to the fixation by the fixation element, which is held on the guide element on the osteosynthesis plate, and the anti-rotation screw, rotational movements of the bone fragment are reliably prevented.

The fixation of the anti-rotation screw on the osteosynthesis plate is improved in that the second recess has an internal thread and the anti-rotation screw on its head has a corresponding external thread.

Greater stability is achieved by this design, in particular a tilting movement of the anti-rotation screw is prevented.

For the minimally invasive introduction of the system according to the invention, it has a target bracket which can be detachably connected to the osteosynthesis plate. This aiming arm enables the osteosynthesis plate to be brought into the desired position in a minimally invasive manner, to be attached to the bone, and the fixation element, the guide element, the anti-rotation screw and the bone splinter fixation element to be inserted into the bone. 10

The drilling of the bones and the assembly of the individual elements are made easier by the fact that the aiming arm has target bores which are aligned with the recesses in the osteosynthesis plate.

It has been shown that it is also possible for the system to perform minimally invasive treatment of bone fractures without the aid of the osteosynthesis plate, provided the cortical bone has sufficient strength.

In this case, the guide element is fastened directly in the corticalis by screwing in according to the invention. The fixation element slidably mounted in or on the guide element is fastened here, as already described, in the broken fracture part of the bone. To prevent rotation of the fracture part, at least one anti-rotation screw can be driven into the corticalis in the supporting section of the bone so that it extends into the soft part of the fragment of the bone loosened by the fracture. Here too, as already described, at least one bone splinter fixation element can be fastened in or on the guide element.

If the fixing element is fastened by screwing it directly into the osteosynthesis plate or also into the corticalis, then the first connecting section is preferably shaped at the end in such a way that a target bracket for the direction of drilling of the bone splitter fixing element can be attached to it in such a way that it is problem-free after drilling Attachment of the bone can be done in or on the guide element. Depending on the operational requirements, guide elements can also be used, in or on which a plurality of bone splinter fixation elements can be attached.

The drilling direction for the anti-rotation screws when using an osteosynthesis plate can also be determined using known drilling templates.

In a further embodiment variant, the connecting section between the fixation element and the guide element is designed in such a way that problem-free sliding among one another is possible, but decoupling by a limit stop, such as a snap ring, a pin, a flange or the like on the connecting section of the guide element or shaft of the fixation element of both parts is prevented because it engages in a circumferential groove.

Another advantage here is that the axial displacement when sliding, e.g. can be limited to a predetermined value by the width of the groove. It has been shown that an axial displacement of up to 10 mm is generally sufficient for a fracture.

In one embodiment, the shaft of the fixation element is mounted in a receptacle of the guide element in a sliding, tilt-stable and axially displaceable manner. In a further embodiment, the shaft of the fixation element is designed such that it engages around the second connecting section of the guide element from the outside. Here, too, it is slidable, tilt-resistant and axially displaceable. Limitation is also possible. It is particularly advantageous if the slidingly mounted connection is designed in such a way that the fixation element can rotate about the axis.

In these embodiments, a fixation recess is arranged centrally for receiving a turning tool at the end of the shaft of the fixation element. This fixation recess can have the shape of an internal thread for receiving a screw or another shape for receiving a non-positive connection element, so that a forced rotation of the fixation element for screwing into the fracture part of the bone is possible. In this case, a continuous turning tool bore for receiving the turning tool is arranged axially in the guide element.

Further objectives, features and possible uses of the present invention result from the following description of the exemplary embodiment with reference to the drawing. All of the described and / or illustrated features, alone or in any combination, form the subject matter of the invention, regardless of their combination in individual claims or their relationship.

1 shows a side view, partly in section, of the system according to the invention for minimally invasive treatment of a fracture of a bone; 2a shows a plan view of the osteosynthesis plate according to the invention; 2b shows a cross section through the osteosynthesis plate shown in FIG. 2a transversely to its longitudinal direction; 3 shows a sectional illustration of a system according to the invention in its installed position; 4 shows a section through the system according to the invention along the line AA in FIG. 3; 5 shows a section through an inventive system approximately along the line BB in FIG. 3, but in a slightly modified embodiment; 6 shows a sectional illustration along the line AA through an alternative embodiment; 7 shows a sectional illustration of a system according to the invention in its installation position without an osteosynthesis plate; Fig. 8 is a sectional view of the connecting section with the inner shaft of the fixation element. Fig. 9 is a sectional view of the connecting section with the outer shaft of the fixation element

A system for minimally invasive treatment of a fracture of a bone is shown in the figures. The system according to the invention is basically suitable for the treatment of different bone fractures. However, it is particularly suitable for proximal humerus or femur fractures, i.e. for those bone fractures that affect the end of the upper arm or thigh bone close to the body. The figures and the following description explain the invention by way of example with reference to the th system for the treatment of a proximal humeral fracture without restricting the invention thereto.

As can be seen from FIGS. 1 and 3, the system designed as a kit contains an osteosynthesis plate 1, a fixation element 2 for fixation in a fragment of the bone 3 loosened by the fracture, and a guide element 4 for the fixation element 2.

The elongate rigid osteosynthesis plate 1 has a fastening section 5, via which the osteosynthesis plate 1 can be fastened to the intact shaft of the bone 3. For this purpose, three through openings 6, 7, 8 arranged in a line are arranged in the approximately rectangular fastening section 5. These make it possible to introduce means for fastening the osteosynthesis plate 1 into the bone 3. In the embodiment shown, the through openings 6 and 8 are circular, while the through opening 7 is an elongated hole extending along the longitudinal axis of the osteosynthesis plate. According to the invention, three cortical screws are provided as means for fastening the osteosynthesis plate. The cortical screw 10 designed for the through hole 7 designed as an elongated hole has a rounded screw head, also referred to as a spherical head. In contrast, the cortical screws 9 and 10 have a cylindrical screw head, which is provided with an external thread. An internal thread corresponding to the external thread of the heads of the cortical screws 9 and 11 is provided in the through openings 6 and 8 of the osteosynthesis plate 1, into which the heads of the cortical screws 9 and 11 can be screwed in to a rash. With this design, the cortical screws 9 and 11 are held firmly and firmly on the osteosynthesis plate in every direction. The cortical screws 9 and 11 all have a thread on their shaft which is suitable for screwing into the corresponding holes provided in the bone 3.

Above the fastening section 5, the osteosynthesis plate 1 has a support section 12, which in the embodiment shown is somewhat wider than the fastening section 5. In a different way, both sections can in particular also be of identical width. For which the insertion of the osteosynthesis plate 1 under a muscle is facilitated in that the free end of the support section 12 has a sliding area with a reduction in thickness and is designed to run flat towards the bone (not shown).

The support section 12 also has an approximately rectangular basic shape. It has (four) bores 13, each of which extends from the front side shown in FIG. 2a to the side of the osteosynthesis plate 1 facing the bone. The holes 13 make it possible to temporarily fix the fracture in order to subsequently insert the fixation element 2 into the fragment of the bone 3 separated by the fracture. This can be done, for example, by so-called Kirschner wires, which are introduced into the bone 3 through the bores 13. In addition, after removing the Kirschner wires, if necessary, additional screws (not shown) can be inserted through the bores 13 into the bone 3 to stabilize the fracture. For this the holes 12 have an internal thread into which the screws can be screwed in at an angle-stable manner via an external thread provided on their head.

Furthermore, the support section 13 has (three) obliquely arranged through holes 38, each of which extends from the front side shown in FIG. 2a into the side surface 14. This can be seen in FIG. 2b, which shows a cross section through the support section 12 in the region of the lower two through holes 38. When the osteosynthesis plate 1 is used in an open, that is to say not minimally invasive, operation, the through holes 38 can be used to fix fragments of fragments (in particular the tubercle majus fragment) with threads.

FIG. 2b also shows that the underside of the osteosynthesis plate 1 is concavely curved in a direction transverse to its longitudinal axis, as a result of which the contact with the bone 3 is improved. The support section 12 of the osteosynthesis plate 1 has a slightly convex shape in the direction of its longitudinal axis. This improves contact with the enlarged head of the bone 3.

A first recess 15 is provided in the support section 12 and extends through the osteosynthesis plate 1. The first recess 15 and the fixation element 2 and the guide element 4 described in more detail below are dimensioned such that the fixation element 2 and the guide element 4 pass through the first recess 15, starting from the position shown in FIG. a borehole to be drilled beforehand therein and brought into the position shown in FIG can. Accordingly, the outer diameter of the fixation element 2 and the guide element 4 is somewhat smaller than the inner diameter of the first recess 15. The first recess 15 in the support section 12 and the guide element 4 are designed such that a longitudinal axis of the guide element 4 and an imaginary tangent to the Bone 3 facing side of the osteosynthesis plate enclose an angle of 50 ° to 70 °, in particular 55 ° to 65 °. The free end of the guide element 4 points away from the fastening section 5. This angular arrangement is achieved in that the first recess 15 extends obliquely through the support section 12.

The fixation element 2 is designed as a screw and has at its front end 16 a self-tapping thread suitable for screwing into the bone 3. At the rear end 17 of the fixation element 2, a shaft 18 is formed, via which it can be connected to the guide element 4. In the embodiment shown, the shaft 18 is hollow.

The guide element 4 takes over the guidance of the fixation element 2. For this purpose, the guide element 4 has a first connecting section 19, via which it can be fixed to the osteosynthesis plate 1. In the second connecting section 20 formed on the opposite free end of the guide element 4, a receptacle 21 for the shaft 18 of the fixation element 2 is provided. The shaft 18 and the receptacle 21 are designed such that the fixation element 2 is received in the guide element 4 in a tilt-stable and axially displaceable manner is. Due to the displaceability of the fixation element 2, any displacements in the area of the fracture that occur during the healing process can be smoothly compensated for. Accordingly, the fixation element 2 designed as a screw can also be referred to as a sliding screw in the illustrated embodiment.

In the direction of rotation, the fixation element 2 is held firmly in the receptacle 21 in the embodiment shown. For this purpose, corresponding driver surfaces 22 are formed on the shaft 18 and in the receptacle 21, as shown in FIGS. 3 and 4. The design enables the fixation element 2 to be screwed into the bone 3 while rotating the guide element 4. At the same time, a rotation lock is produced in this way, which prevents relative rotation between fixation element 2 and guide element 4. In the embodiment shown, two parallel, opposing driver surfaces 22 are provided on the outside of the otherwise cylindrical shaft 18. However, another non-circular corresponding cross-sectional shape of the shaft 18 and the receptacle 21, for example a square or hexagon, can also be used.

In Figure 6, which shows a sectional view as in Figure 4, the section through the shaft 18 and the receptacle 21 of an alternative embodiment is shown. Here, the fixation element 2 and the guide element 4 are not rotationally fixed to one another. This is achieved by a circular cross section of shaft 18 and receptacle 21, which have no driver surfaces exhibit. This design enables the guide element 4 to be screwed onto the fixation element 2 intraoperatively, which can facilitate assembly.

The guide element 4, which has a smooth cylindrical outer shape, is continuous and can therefore also be referred to as a sliding sleeve. The outer diameter of the guide element 4 and the first recess 15 in the osteosynthesis plate 1 is dimensioned such that the guide element 4 in the osteosynthesis plate 1 is held in a tilt-stable and precisely fitting manner. The system can be adapted to different sized bones by different lengths of the guide element 4.

Movements of the guide element 3 after insertion into the osteosynthesis plate 1 are undesirable. Therefore, fasteners 23 are provided which hold the guide element 4 axially fixed in both directions. In the embodiment shown, the fastening means 23 are formed by the projection in the form of a nose 24 of the guide element 4, which protrudes laterally on the guide element 4 and can be brought into engagement with a groove 25 in the osteosynthesis plate 1. The groove 25 extends transversely, in particular perpendicularly to the longitudinal axis of the guide element 4 and is arranged in the region of the first diminution 15. Figure 5 illustrates this. According to FIG. 3, the groove 25 extends up to the top of the osteosynthesis plate 1. As a result, the nose 24 can easily be inserted into the groove 25. Alternatively or additionally, as shown in FIG. 5, the groove 25 can have an enlarged, outwardly open section 26, via which the nose 24 can be inserted into the groove 25. According to the invention, means 27 are further provided to prevent rotation of the bone fragment detached by the fracture. In the illustrated embodiment, these comprise an anti-rotation screw 28 having a head, which can be inserted into the detached bone fragment through at least one second recess 29 formed in the support section 12 of the osteosynthesis plate 1. In the embodiment shown, the second recess 29 is arranged in such a way that the anti-rotation screw 28 extends parallel to the longitudinal axis of the guide element 4, specifically on the side of the first recess 15 facing the fastening section 5. Alternatively and differently than shown, the anti-rotation screw 28 and the guide element 4 can also be arranged at an angle to one another (in particular 10 ° to 45 °), which under certain circumstances enables even better fracture stabilization.

Like the cortical screws 9 and 11, the anti-rotation screw 28 has an enlarged head 30 with an external thread, which can be screwed into a corresponding internal thread provided in the second recess 29 up to a stop. The anti-rotation screw 28 is designed as a shaft screw, which is not provided over the entire length of the screw shaft, but only at the end opposite the head 30, with a thread suitable for screwing into the bone 3.

Embodiments are not shown in which a plurality of anti-rotation screws are arranged and used in the fastening section. The system according to the invention also provides a bone splinter fixation element 31. However, this does not necessarily have to be used. It is particularly advantageous if the fracture has resulted in three or more bone fragments. In the embodiment shown for the treatment of a proximal humeral fracture, the tuberculum majus fragment can be securely fixed by the bone splinter fixation element 31. This takes place in that the bone splinter fixation element 31, which is designed as a screw in the embodiment shown, is introduced into and held by a transverse bore 32 formed in the guide element 4. The bone splinter fixing element 31 has an elongated shaft which is provided at its lower end with a thread which can be screwed into an internal thread provided in the transverse bore 32. The transverse bore 32 and thus the longitudinal axis of the bone splinter fixation screw 31 on the one hand and the longitudinal axis of the guide element 4 on the other hand enclose an angle between 60 ° and 100 °, in particular between 70 ° and 90 °.

Here, the longitudinal axis of the bone splinter fixation screw 31 is inclined away from the osteosynthesis plate 1 when the angle W is less than 90 ° and towards the osteosynthesis plate 1 when the angle W is more than 90 °.

In the embodiment shown, the bone splinter fixation element 31 is designed as a claw screw which, under its expanded screw head, has a pressure body 33 having a plurality of claws. In order to be able to screw the bone splinter fixation element 31 into the transverse bore 32 without problems, it is necessary to bring the guide element 4 into the correct rotational position beforehand, since otherwise the bone splinter fixation element 31 would miss the opening of the cross bore 32. Alignment means are used for this, by means of which the rotational position of the guide element 4 relative to the osteosynthesis plate 1 can be set and / or controlled. In the embodiment shown, the correct positioning of the guide element 4 is ensured by providing a stop 34 in the groove 25 for abutment against the nose 24, which limits the rotational movement of the guide element 4.

Thus, by moving the nose 24 until it abuts the stop 34, the guide element 4 can be correctly and precisely aligned.

FIG. 1 also shows a aiming arm 35, which makes it possible to position the system according to the invention in a minimally invasive manner and to fasten it to the bone. The aiming arm 35 is connected to the osteosynthesis plate 1 without play, but releasably, via a clamping cut 36. For this purpose, a dovetail guide can be provided between the aiming arm 35 and the osteosynthesis plate 1. The aiming arm 35 makes it possible to provide the necessary drill holes in the bone 3 and then to mount the further elements of the system according to the invention on the bone 3. The aiming arm 35 is particularly important in the case of minimally invasive restoration, since the remaining system components cannot be assembled under direct visual control. Target holes 37 are provided in the aiming arm 35, which are aligned with the recesses in the osteosynthesis plate. These holes 37 are used in a known manner to guide drills in order to be able to drill 3 holes in the bone. Likewise, the various elements of the system according to the invention can be brought to their intended position in a minimally invasive manner with the aid of the guide.

In FIG. 7 the system is shown in the installed state as in FIG. 3, the osteosynthesis plate being dispensed with due to the sufficient strength of the corticalis.

FIGS. 8 and 9 show a section of the connecting section between the guide element 4 and the fixing element 2. In FIG. 8, the shaft 18 is located in the second connecting section 20 in such a way that an axial and tilt-proof sliding movement is possible. The arranged limit stop 39, here in the form of a pin, which engages in a circumferential groove, prevents the shaft 18 from slipping out of the second connecting section 20 unintentionally. In contrast to FIG. 8, the shaft 18 of the fixation element is arranged in FIG. 9 in such a way that it surrounds the second connecting section 20 in an axially displaceable and tilt-stable manner on the outside. Here again, a limit stop 39 is arranged. The axial mobility can thus be set to a predetermined length. In order for the fixation element 2 to be screwed in, which can also be rotatably mounted in or around the second connecting section 20, a fixation recess 41 is arranged centrally at the rear end of the fixation element 17. In this example it is an internal thread into which a turning tool, not shown, which is Tool bore 40 of the guide element 4 can be guided, is screwed in and thus generates a non-positive connection.

All elements of the system according to the invention remaining in the body are made of titanium or stainless steel. The aiming arm 35 is made of wood or plastic to allow fluoroscopy.

The function and handling of the system according to the invention is explained below on the basis of the procedure for an operation of a sybital humerus fracture.

After a necessary repositioning of the fracture fragments of a proximal humeral fracture, a small incision is made in the area of the upper arm below the upper arm head and the osteosynthesis plate 1 is inserted through it to the bone and then carefully pushed up along the bone 3 while scraping off the muscles. The aiming arm 35 is already firmly connected to the osteosynthesis plate 1. In this way, the osteosynthesis plate 1 is pushed to the desired position until the support section 12 comes to lie adjacent to the fracture. Then the osteosynthesis plate 1 by means of the cortical screws 9, 10, 11 on the. Bone 3 shaft fixed. For this purpose, a drill guided in a known manner through the target bores 37 in the aiming arm 35 is driven through the through openings 6, 7 and 8 into the shaft of the bone 3, and the corresponding cortical screws 9, 10, 11 are inserted into the bone. Here, the cortical screw 10 having the ball head is first mounted. The as long Hole-shaped through opening 7 then allows the exact position of the osteosynthesis plate 1 to be corrected relative to the bone 3 before the position of the osteosynthesis plate 1 is finally fixed by inserting the cortical screws 9 and 11 into the through openings 6 and 8.

The fracture can then be temporarily fixed by inserting 13 Kischner wires through the holes into the part of the bone 3 affected by the fracture. This provisional fixation is important in order to be able to drill holes in the bone 3 in the next step through the first and second recesses 15, 29 which extend into the head fragment detached by the fracture. For this purpose, as in all other drill holes to be made in the bone 3, the guidance through the target bores 37 formed in the aiming arm 35 is used, which are aligned with the corresponding recesses 15, 29 or through openings 6, 7, 8 of the osteosynthesis plate 1.

After completion of the drill holes, the fixation element 2 with its self-tapping thread is screwed into the head fragment loosened by the break and thereby fixed. The screwing in can be carried out with the help of a suitable tool, possibly also using the

Guide element 4 happen, which is connected with its second connecting portion 20 to the fixation element 2. In any case, the guide element 4 is pushed through the first recess 15 with a suitable tool and positioned so that it is in the bone

3 extends, the shaft 18 of the fixation element 2 in the Recording 21 is received and the nose 24 is inserted into the groove 25. The guide element 4 is thus secured against undesired axial movement.

Slightly below and parallel to the guide element 4, the anti-rotation screw 28 is inserted using the aiming arm 35 in order to fix the head fragment. The risk of undesirable fracture movements during the operation is reduced if the anti-rotation screw 28 having a smaller diameter is inserted in front of the fixation element 2 having a larger diameter.

If necessary, a further drill hole is made through this fragment from above at an angle (based on the position of the bone shown in FIG. 3) into the bone 3 using the aiming arm 35 to fix the tubercle majus fragment. This takes place before the insertion of the guide element 4 into the bone 3. After the guide element 4 has been positioned by rotating the nose 24 up to the stop 34 such that the borehole for the bone splinter fixation element 31 is aligned with the transverse bore 32, the bone splinter fixation element 31 is inserted into the Cross bore 32 screwed in and the tubercle majus fragment fixed in this way.

The Kirschner wires for temporary fixation are then removed and, if necessary, replaced by screws which extend through the bores 13 and are screwed with their heads into the internal thread formed in the bores 13. Finally, the aiming arm on the clamping section 36 is detached from the osteosynthesis plate 1 and removed therefrom. The osteosynthesis plate 1, the fixation element 2, the guide element 4, the anti-rotation screw 28, the bone splinter fixation element 31 and the cortical screws 9, 10, 11 remain in the body as an implant until the fracture has healed completely.

If the corticalis has sufficient strength, the guide element 4 can also be fastened with the fixation element 2 directly in the corticalis of the bone 3. To prevent rotation of the fragment, at least one anti-rotation screw 28 can also be inserted directly in the fastening section.

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LIST OF REFERENCE NUMBERS

Osteosynthesis plate Fixation element Bone guide element Fastening section Through opening Through opening Through opening Corticalis screw Corticalis screw Corticalis screw Support section Bores Side surface First recess Front end of the fixation element Rear end of the fixation element Shank First connection section Second connection section Admission driving surface Fastening device Nose groove Extended section Means for preventing rotation Anti-rotation screw Second recess Head bones splinter Cross bore Pressure body Stop Aiming arm Clamping section Target bores Through holes Limit stop Turning tool bore Fixation recess

Claims

claims

1. System for minimally invasive treatment of a fracture of a bone (3), in particular a proximal humerus or femur fracture, comprising an osteosynthesis plate (1) which has a support section (12) which is connected to a

Support surface on the bone (3) can be positioned adjacent to the fracture, and an attachment section

(5) to fix the osteosynthesis plate (1) on the

Bone (3), a fixation element (2) for fixing in a fragment of the bone (3) loosened by the fracture, and a guide element (4) which can be fastened to the osteosynthesis plate (1) via a first connecting section (19) and which has a second connecting section (20) for guiding the fixation element (2), the support section (12) of the osteosynthesis plate (1) having at least a first recess (15) and through the fixation element (2) and the guide element (4) the first recess (15) can be inserted into the bone (3).

2nd System according to claim 1, characterized in that the first recess (15) in the support section (12) and the guide element (4) are formed such that a longitudinal axis of the guide element (4) and a tangent on the side facing the bone (3) form an angle between 50 ° and 70 °, in particular between 55 ° and 65 °, of the osteosynthesis plate (1).

3. System according to claim 1 or 2, so that fastening means (23) are provided which hold the guide element (4) axially in both directions after insertion into the osteosynthesis plate (1).

4. System according to claim 3, d a d u r c h g e k e n n z e i c h n e t that alignment means are provided by which the rotational position of the guide element (4) relative to the osteosynthesis plate (1) can be adjusted and / or controlled.

5. System according to claim 3 and 4, characterized in that the fastening means (23) in the first recess (15) of the support section (12) formed groove (25) and a corresponding, on the guide element (4) formed nose (24) comprise, which can be inserted into the groove (25).

6. System according to claim 5, characterized in that in the groove (25) a stop (34) for abutment against the nose (24) is provided, which limits a rotational movement of the guide element.

7. System according to claim 3 or 4, characterized in that the fastening means (23) comprise an external thread formed on the first connecting section (19) of the guide element (4) and an internal thread which can be brought into engagement therewith and formed in the first recess (15) ,

8. System according to any one of claims 1 to 7, characterized in that the second connecting section (20) of the guide element (4) is designed as a receptacle (21) in which a shaft (18) of the fixation element (2) is tilt-stable and axially displaceably received is.

9. System according to claim 8, so that the shaft (18) of the fixation element (2) has driver surfaces (22) by means of which the fixation element (2) is held in the receptacle (21) in a rotationally fixed manner.

10. System, according to one of claims 1 to 9, characterized in that it includes a bone splitter ixierungselement (31) which is fixable in or on the guide element (4), in particular in a transverse bore (32) provided therein.

11. The system according to claim 10, characterized in that the transverse bore is arranged in the guide element (4) such that a longitudinal axis of the bone splinter fixing element (31) and a longitudinal axis of the guide element (4) form an angle between 60 ° and 100 °, in particular between 70 Include ° and 90 °.

12. The system of claim 10 or 11, so that the bone splitter fixing element (31) is designed as a screw which has a pressure body (33) with claws.

13. System according to claim 1 to 12, so that means (27) are provided for preventing rotation of the detached bone fragment.

14. System according to claim 13, characterized in that the means for preventing rotation include an anti-rotation screw (28) having a head (30), which by at least a second recess (29) in the support portion (12) of the osteosynthesis plate (1) in the detached fragment of the bone (3) can be used.

15. System according to claim 14, characterized in that the second recess (29) has an internal thread and the anti-rotation screw (28) on its head (30) has a corresponding external thread.

16. System according to one of claims 1 to 15, g e k e n e z e i c h n e t d u r c h, a aiming arm (35) which is releasable via at least one clamping section (36) with the osteosynthesis plate (1).

17. The system of claim 16, so that the aiming arm (35) has target holes (37) which are aligned with the recess in the osteosynthesis plate (1) when the aiming arm (35) is connected to the osteosynthesis plate (1).

18. System according to claim 1, so that the fixation element (2) has a screw head with a self-tapping thread.

19. System for minimally invasive treatment of a fracture of a bone (3), in particular a proximal humerus or femur fracture, comprising a support section (12) in the corticalis or by means of an osteosynthesis plate (1) with an additional fastening section (5) on the bone (3) , a fixation element (2) for fixing in a fragment of the bone (3) loosened by the fracture, and a guide element (4), which via a first connecting section (19) in the support section (12) on the osteosynthesis plate (1) or in the corticalis can be fastened and has a second connecting section (20) for guiding the fixation element (2), wherein the second connecting section (20) of the guide element (4) and the shaft (18) of the fixation element (21) are designed as tilt-resistant and axially displaceable slide bearings, and the system as a means for preventing rotation of the detached bone fragment has at least one anti-rotation screw (28 ) is arranged in the support section (12) and can be inserted into the detached fragment of the bone.

20. System according to claim 19, characterized in that the second connecting section (20) of the guide element (4) and the shaft (18) of the fixation element (2) are designed as sliding bearings so that the shaft (18) of the fixation element (2) in or is arranged around the second connecting section (20).

21. System according to claim 19, so that the fixation element (2) as a sliding screw with a thread at its front end (16) and the shaft (18) in or around the second connecting section (20) is tilt-stable and axially movable.

22. System according to claim 19, characterized in that the shaft of the fixation element (2) in or around the second connecting section (20) is axially limited movable.

23. System according to one of claims 19 to 22, so that the shaft (18) and the second connecting section (20) are circular in such a way that an axial rotation of the fixation element (2) in or around the guide element (4) is possible.

24. System according to claim 19, characterized in that the support section (12) and the guide element (4) are formed such that a longitudinal axis of the guide element (4) and a tangent to the outside of the cortical bone (3) an angle between 50 ° and 70 °, especially between 55 ° and 65 °.

25. The system as claimed in claim 19, so that it includes at least one bone splinter fixing element (31) which can be fixed in or on the guide element (4), in particular in at least one transverse bore (32) provided therein.

26. System according to claim 25, characterized in that a transverse bore (32) is arranged in the guide element (4) in such a way that a longitudinal axis of the bone splinter fixing element (31) and a longitudinal axis of the guide element (4) form an angle between 60 ° and 100 °, include especially between 70 ° and 90 °.

27. System according to claims 19, 25 or 26, so that the bone splitter fixing element (31) is designed as a screw which has a pressure body (33) with claws.

28. The system as claimed in claim 19, so that fastening means (23) are provided which hold the guide element (4) axially fixed in both directions after insertion into the osteosynthesis plate (1) or into the corticalis.

29. System according to claim 19, so that alignment means are provided by means of which the rotational position of the guide element (4) can be adjusted and / or controlled relative to the bone splitter fixing element (31).

30. System according to claim 19, so that the guide element (4) axially has a turning tool bore (40) for receiving a turning tool.

31. System according to claim 19, so that the fixation element (2) has a screw head with a self-tapping thread.