The invention relates to an aiming device for inserting angle-stable, long screws in the articular region of a bone for optimal treatment of joint fractures with plate/screw systems, using a distal humerus as an example.
For example, the patents US-20020032465-A1, US-20030220651-A1, U.S. Pat. No. 4,625,718, U.S. Pat. No. 4,848,327 and WO-03041595-A1 may be mentioned in relation to the prior art.
However, US 2003/0009171 A1 will be discussed in particular. This discloses a multiplicity of aids for fitting an elbow prosthesis, in particular an aiming device for drilling the articular region of the bone along its joint axis. This aiming device consists of a bow which is clamped on the articular region by means of a screw spindle. A guide zone for inserting a drill into the articular region along said joint axis is integrated in the screw spindle. The bore which can be produced in this manner serves here for inserting a pin which subsequently permits alignment of the elbow prosthesis and is then removed again. The insertion of a screw is not envisaged in this apparatus.
Even if this device disclosed in US 2003/0009171 A1 is intended for a completely different purpose, the preparation of bores therewith which is intended by the inventor could in certain circumstances be carried out, even if with considerable disadvantages. The known device has no possibility for preventing the risk of penetration into the joint, which is also unimportant in the course of fitting an elbow prosthesis since the joint is removed in any case and is replaced. However, during osteosynthesis, treatment of the bone in as gentle a manner as possible is a precondition. As already mentioned, the placing of the distal screw required in osteosynthesis after drilling is complete is possible only if the device or at least the screw spindle were to be removed. However, this would eliminate the compression produced by the device for ensuring cohesion of any bone fragments. During the entire course of the operation with this known device, continuous stability is therefore not possible. Finally, the drill would disadvantageously have to have at least the length of the screw spindle and of the desired drilled hole, with the result that increased vibrations may adversely influence the drilling.
It is the object of the present invention to eliminate these disadvantages.
It should be possible by means of the invention to insert distal screws which are as long as possible through the bone in that region of the articular block which is in the vicinity of the joint, for which purpose the bores are accordingly to be introduced in a targeted manner and without any penetration into the joint, with the result that, after insertion of a screw, optimal fixation in the good bone should be achieved. Any screws opposite to one another should moreover be capable of being brought past one another as closely as possible in a targeted manner and approximately along an axis without collision. This should be ensured in particular directly during the first attempt in order to protect the bone as far as possible. The compression of the bone fragments of the articular block during the entire duration of the operation is also to be maintained in order thereby to ensure a stable connection and good clinical results.
The aiming device according to the invention and according to claim 1 consists of a bow, optionally having various cut-outs for weight reduction, and achieves the objects set. A preferred embodiment has the following design, a screw spindle which can be actuated by means of a nut and is intended for fixing the aiming device on the articular region of the bone is provided on the bow. A cylindrical guide which in turn bears an adaptor bush so as to permit rotational movement is mounted on the opposite end of the bow. Cylindrical guide and adaptor bushing are suitable firstly for guiding a bone screw and secondly for bearing a drill bushing having preferably an external thread. A target plate for connection to a bone plate is intended for producing a temporary plug connection with the adaptor bushing of the aiming device.
Before the operation, the target plate is screwed to a lateral implant (bone plate). By means of the plug connection, the target plate with the lateral implant is mounted on the adaptor bushing of the aiming device. The drill bushing is then inserted into the orifice in the cylindrical guide and, passing through the adaptor bushing and the target plate; comes into contact with complementary internal thread in a bore of the implant. Everything is now placed together on the fragmented bone, clamped by the screw spindle of the aiming device and fixed with a proximal bone screw through the implant. With the aid of the aiming device according to the invention, it is therefore possible to determine the point of emergence of the distal, angle-stable screws prior to drilling. When everything is correctly aligned, drilling can be effected through the integrated drill bushing. Furthermore, the length of the screw to be used and hence the depth of the hole to be drilled can be determined directly using the aiming device, in particular with reference to the scale mounted on its screw spindle.
After removal of the drill bushing screwed to the implant, the compression persists via the plug connection between adaptor bushing and target plate. This is an important advantage in contrast to the known device. By using the target plate, it is therefore possible, after removal of the drill bushing, to screw in the screw while the aiming bow is mounted, i.e. under compression. The removed drill bushing now also frees the larger diameter required by the bone screw. The bone screw fits firmly with its head on the same implant thread which the drill bushing has previously held. In addition, the alignment of further screws is simplified in that the position of the already inserted screw is indicated by the aiming device so that they are inserted in a completely targeted manner parallel to the joint axis and through the best bone of the distal part. When this has been completed, the aiming device and the target plate can be removed.
Further developments of the invention are shown in the Figures and indicated in the independent patent claims.
The list of reference numerals is part of the disclosure.
The invention is explained in more detail schematically and by way of example with reference to figures.
The figures are described in relation to one another and as a whole. Identical reference numerals denote identical components, and reference numerals with different indices indicate functionally identical or similar components.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2004/000441 | 2/20/2004 | WO | 00 | 5/2/2007 |
Publishing Document | Publishing Date | Country | Kind |
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WO2005/089660 | 9/29/2005 | WO | A |
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3674375 | Reed et al. | Jul 1972 | A |
3867932 | Huene | Feb 1975 | A |
4159716 | Borchers | Jul 1979 | A |
4235428 | Davis | Nov 1980 | A |
4364381 | Sher et al. | Dec 1982 | A |
4465065 | Gotfried | Aug 1984 | A |
4625718 | Olerud et al. | Dec 1986 | A |
4710075 | Davison | Dec 1987 | A |
4848327 | Perdue | Jul 1989 | A |
4997434 | Seedhom et al. | Mar 1991 | A |
5152764 | Goble | Oct 1992 | A |
5254079 | Agbodoe et al. | Oct 1993 | A |
5409493 | Greenberg | Apr 1995 | A |
5713117 | Bliss | Feb 1998 | A |
5893553 | Pinkous | Apr 1999 | A |
6299616 | Beger | Oct 2001 | B1 |
20020032465 | Lemer | Mar 2002 | A1 |
20020087163 | Dixon et al. | Jul 2002 | A1 |
20030009171 | Tornier | Jan 2003 | A1 |
20030220651 | Pusnik et al. | Nov 2003 | A1 |
20040102788 | Huebner et al. | May 2004 | A1 |
Number | Date | Country |
---|---|---|
0 132 284 | Jan 1985 | EP |
132284 | Jan 1985 | EP |
1 354 562 | Oct 2003 | EP |
WO 03041595 | May 2003 | WO |
Entry |
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International Search Report of PCT/IB2004/000441, mail date Nov. 11, 2004. |
Number | Date | Country | |
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20070239168 A1 | Oct 2007 | US |