EP1643917A1

EP1643917A1 - Aiming device

Info

Publication number: EP1643917A1
Application number: EP03737813A
Authority: EP
Inventors: Romano Matthys-Mark
Original assignee: Synthes AG Chur
Current assignee: Synthes GmbH
Priority date: 2003-07-14
Filing date: 2003-07-14
Publication date: 2006-04-12
Also published as: AU2003245785A1; WO2005004728A1; BR0318402A; CN1832704A; CA2532653A1; US8114093B2; JP2007504845A; US20060161168A1

Abstract

The invention relates to an aiming device (1) which is used to guide and place longitudinal bone fixing means (4) in a predetermined direction with respect to a bone fixing device (6). The aiming device (1) comprises securing means (5) which can be detachably secured to a bone fixing device (39). The aiming device comprises A) a first centering part (13) which can be placed on the bone fixing device (39), and a second centering part (3) which is arranged at a distance from the first centering part; B) both of the centering parts (13;3) comprise at least one pair of guiding elements (14, 29) which are arranged in a coaxial manner in relation to each other.

Description

target device

The invention relates to a target device according to the preamble of patent claim 1.

In the case of bone fixation devices, in particular bone plates, the problem arises of attaching them to the bone fragments by means of suitable longitudinal bone fixation means, such as bone screws, bone wires, bone pins or Kirschner wires, so that the longitudinal bone fixation means have a very specific direction to the bone fixation device, in particular a very specific angle Have bone plate.

This problem arises in particular in the case of bone plates which consist of a plastic and do not yet have plate holes, for example according to WO01 / 12081.

A device with a centering sleeve for placing the bone fixation means on a plastic plate is known from DE-U 200 19 026. This known device comprises a aiming arm, to which a bone plate can be fastened by means of a fastening means, and a guide part which is displaceable on the aiming arm and displaceable and rotatable relative to the bone plate. The only guide part is tubular and is used for centering and guiding surgical instruments and / or implants. The tubular design of the guide part only allows the inclusion of a bone fixation agent. In the event that, for example, several Kirschner wires are to be placed on a bone plate, the guide part for each Kirschner wire to be placed has to be displaced and realigned relative to the insertion handle, which means that four Kirschner wires, for example, have to be put in a lot of time.

The invention seeks to remedy this. The invention has for its object to provide a target device which on the one hand allows the positioning of drilling instruments or drill sleeves in a predetermined direction to the bone and / or on the other hand the surgeon the introduction of longitudinal Bone fixation means (Kirschner wires) allowed in a predetermined, preferably divergent direction in the bones.

The invention achieves the stated object with a target device which has the features of claim 1.

The advantages achieved by the invention can essentially be seen in the fact that, thanks to the aiming device according to the invention:

- The longitudinal bone fixation agent can be precisely positioned by the surgeon without first having to implant a Kirschner wire into the bone;

- The position of the Kirschner wires is clearly predetermined by the anatomy on the humerus and the selected position below the axilary nerve and is reproducible by the target device (this is not the case with a target device that allows the user to freely choose the positioning);

- The bone fixation element can be implanted as well as explanted.

In a preferred embodiment, the two centering parts have at least two pairs of guides which are coaxial to one another. Each pair of guides comprises a guide in the first centering part, which is arranged at the front end of the aiming arm and can be connected to the bone fixation device, and a guide in the second centering part, which is arranged on the handle part of the aiming arm. The guide pairs are preferably designed such that the axes of the different guide pairs diverge. This has the advantage that several bone fixation means (Krschner wires) can be implanted without having to adjust and readjust the target device to the directions of the individual Kirschner wires. The bone fixation device is preferably designed as a bone plate.

In another embodiment, the two centering parts and the aiming arm are designed such that the two centering parts on the aiming device are interchangeable. This achieves the further advantage that a set of centering part pairs with different orientations of the guide pairs is longitudinal Bone fixation agents can be placed at predetermined angles, for example to a bone plate.

In yet another embodiment, the guides are fixed with respect to the centering parts, so that undesired displacements of the guides relative to the centering parts are not possible.

In a further embodiment, the centering parts can only be connected to the target device in a position defined with respect to the target device. This configuration on the one hand eliminates errors in the assembly of the target device and on the other hand the positions of the two centering parts are easy to find, which considerably simplifies the assembly of the target device.

In yet another embodiment, the aiming device comprises a two-part aiming arm with a sleeve suitable for receiving the fastening means between the aiming arm and bone fixation means and a handle part arranged transversely to the central axis. The first centering part is preferably fixedly connected to this sleeve, the sleeve being secured relative to the handle part against rotation about the central axis of the sleeve.

In another embodiment, the guides in the second centering part arranged on the handle part of the insertion handle are designed as bores, so that the drill sleeves or bone fixation means that can be inserted into the bores are enclosed over their entire circumference and cannot shift laterally. The guides in the first centering part, which can be fastened, for example, to a bone plate, are preferably designed as centering grooves which are coaxial to the axes of the bores.

In yet another embodiment, the aiming device comprises one or more bores for receiving longitudinal aiming aids, which are preferably designed in the form of straightening rods and simplify the alignment of the aiming device on the patient's body for the surgeon. The bone plates used are preferably made of PEEK, an implantable plastic with very good mechanical properties. The plate is provided with a central hole, which is used for the temporary fixation of the target instrument on the plate. Due to the conical internal thread (suitable for the head locking screws) in the hole, but also after fixing the Kirschner wires and removing the target instrument, a corresponding bone screw can be fixed in it in order to additionally anchor the bone plate with the bone.

Further advantageous embodiments of the invention are characterized in the dependent claims.

The invention is explained in more detail below on the basis of the partially schematic illustration of an exemplary embodiment.

Show it:

1 shows a longitudinal section through an embodiment of the aiming device according to the invention;

1 shows an embodiment of the aiming device 1 according to the invention, which comprises a two-part aiming arm 2, a first and a second centering part 13; 3 for receiving and guiding four bone fixation means 4, for example Kirschner wires, and a fastening means 5 which can be fastened to a bone plate 6.

The two-part aiming arm 2 consists of a longitudinal, hollow cylindrical sleeve 8 with a central axis 9 and a handle part 7, which can be fastened at the rear end 11 of the sleeve 8 by means of a screw 10 and is arranged transversely to the central axis 9. The first centering part is at the front end 12 of the sleeve 8 13 attached, which includes skew to the central axis 9 guides 14 in the form of centering grooves for the bone fixation means 4, so that the bone fixation means 4 are guided through the guides 14 of the first centering part 13 immediately before they penetrate into the bone plate 6. The central bore 15 of the sleeve 8 penetrates it first centering part 13 likewise, so that the likewise cylindrical fastening means 5 can be passed through the central bore 15 coaxially to the central axis 9. The sleeve 8 is locked on the handle part 7 against rotation about the central axis 9 by means of an anti-rotation device 34. The anti-rotation device 34 is realized by the screw 10 which can be screwed into the handle part 7, the tip 35 of which can be received in a recess 36 on the sleeve 8, so that after the screw 10 has been locked, the sleeve 8 is fixed together with the centering part 13 in the handle part 7 ,

The fastening means 5 is provided at its tip 16 with a conical external thread 17, which can be screwed into a complementary internal thread 18 in the bore 40 made in the bone plate 6. The fastening means 5 is fastened together with the bone plate 6 to the insertion handle 2 by means of a nut 21, which can be screwed via an external thread 20 attached to the rear end 19 of the fastening means 5 and rests on the handle part 7.

The second centering part 3 is designed as a cuboid block and is provided with three spherical depressions 23 on its side surface 22 directed against the aiming arm 2, while the aiming arm 2 has three spherical elevations 25 on its end face 24 directed against the second centering part 3, which are complementary to the depressions 23 having. The elevations 25 engaging in the depressions 23 secure the second centering part 3 against rotation relative to the insertion handle 2. The second centering part 3 is fastened by means of a screw 26, which can be screwed into a corresponding bore 27 having an internal thread in the second centering part 3, and the screw head 28 of which rests on the grip part 7. Furthermore, the second centering part 3 comprises four guides 29, which penetrate the second centering part 3 transversely to the central axis 9 and are designed in the form of bores, the axes 30 of which run transversely to the central axis 9 and are skewed relative to one another. The guides 29 are arranged such that their axes 30 are aligned with the guides 14 designed as centering grooves in the first centering part 13, so that the bone fixation means 4, when they are pushed through the guides 29, both in the guides 29 arranged away from the bone plate 6 as well as in the guides 14 located near the bone plate 6. Furthermore, holes 31 for receiving aiming aids 32, 33 in the form of straightening rods are provided on the centering part 3 and on the grip part 7. The bores 31 are aligned such that the first aiming aid 32, which can be attached to the handle part 7, is perpendicular to the central axis 9, while the second aiming aid 33, which can be attached to the centering part 3, stands in the direction of the connecting straight line between the centering part 3 and the centering part 13. The target aids 32, 33 enable the surgeon to align the target device 1 with respect to the bone to be treated.

The use and function of the target device according to the invention is described in more detail below on the basis of the surgical method for the proximal humerus: A) Implantation:

1. There is a rough reduction of the fractured proximal humerus over the soft tissues;

2. 2 - 3 cm skin incision below the axilary nerve on the proximal humerus;

3. Bluntly prepare the way to the shaft with your index finger;

4. Guide the aiming device with the mounted plate to the shaft and position it accordingly using the external target wires;

5. Anchoring the target device in the predetermined position on the humeral shaft via a 2.5 mm K-wire;

6. Insert the drill sleeve into the marked hole in the target instrument and advance it to the plate with a circular oscillating motion around the longitudinal axis;

7. Insert the 2.0 mm drill bit. Before drilling, check the alignment of the target instrument along the longitudinal axis again and correct if necessary. With the correct position along the longitudinal axis and the height, the cortex is drilled out in the shaft area;

8. Remove the 2.0 mm drill and insert the first 2.5 mm K-wire up to the fracture line. Leave the drill sleeve in the target instrument and use the second drill sleeve for the next Kirschner wire; 9. Same procedure (pre-drilling and inserting the K-wire up to the fracture line) for the remaining three K-wires; 10. Definitive reduction of the fracture and subsequent screwing in of the Kirschner wires to the end position chosen by the surgeon;

11. Remove the target device from the plate; 12. Cut the protruding ends of the Kirschner wires with the cutter as close as possible to the surface of the board;

13. The ends of the Kirschner wires now protrude approx. 8-10 mm from the plate surface.

14. End of osteosynthesis.

B) Explantation:

1. 2 - 3 cm skin incision below the axilary nerve on the proximal humerus;

2. Prepare the path bluntly to the plate with your index finger;

3. Guide the aiming device to the plate and fasten it again with the fastening screw on the plate;

4. inserting the extraction bolt into the target device up to the end of the Kirschner wire;

5. Turn the extraction bolt counterclockwise and remove the Kirschner wire by hand. The same procedure for the remaining Kirschner wires;

6. Remove the target device

7. End of explantation.

Claims

claims

1. Aiming device (1) for guiding drilling instruments, drill sleeves and / or guiding and setting longitudinal bone fixation means (4) in a predetermined direction relative to a bone fixation device (39), the aiming device (1) with fastening means (5) for releasable fastening is provided on a bone fixation device (39); characterized in that the target device (1)

A) comprises a first centering part (13) suitable for bearing against a bone fixation device (39), and a second centering part (3) spaced therefrom, wherein

B) the two centering parts (13; 3) have at least one pair of coaxial guides (14; 29).

2. Target device (1) according to claim 1, characterized in that the bone fixation device (39) is a bone plate (6).

3. Aiming device (1) according to claim 1 or 2, characterized in that the two centering parts (13; 3) have at least two pairs of guides (14; 29) which are coaxial with one another, the axes (30) of the guide pairs diverging.

4. Target device (1) according to one of claims 1 to 3, characterized in that the two centering parts (13; 3) on the target device (1) are interchangeable.

5. Aiming device (1) according to one of claims 1 to 4, characterized in that the guides (14; 29) with respect to the centering parts (13; 3) are fixed.

6. Target device (1) according to one of claims 1 to 5, characterized in that the centering parts (13; 3) can only be connected to the target device (1) in a position defined with respect to the target device (1).

7. Aiming device (1) according to one of claims 1 to 6, characterized in that it has a two-part aiming arm (2) with a for receiving the fastening means (5) suitable sleeve (8) having a central axis (9) and a handle part (7) arranged transversely to the central axis (9).

8. Aiming device (1) according to claim 7, characterized in that the first centering part (13) is fixedly connected to the sleeve (8) and the sleeve (8) is secured relative to the handle part (7) against rotation about the central axis (9) is.

9. Aiming device (1) according to one of claims 1 to 6, characterized in that the guides (29) in the second centering part (3) are bores with axes (30).

10. Aiming device (1) according to claim 9, characterized in that the guides (14) in the first centering part (13) to the axes (30) are coaxial centering grooves.

11. Aiming device (1) according to one of claims 1 to 11, characterized in that it has one or more bores (31) for receiving longitudinal aiming aids (32; 33), preferably in the form of straightening rods.