WO2003043508A1

WO2003043508A1 - Equipment for the fixation of intramedullary nails

Info

Publication number: WO2003043508A1
Application number: PCT/HU2002/000117
Authority: WO
Inventors: József Farkas; Tibor Smutzer
Original assignee: Sanatmetal Kft.
Priority date: 2001-11-19
Filing date: 2002-11-12
Publication date: 2003-05-30
Also published as: AU2002366003A1

Abstract

The subject of the invention relates to a set of equipment for the simplification of the fixing of intramedullary nails which contains an intramedullary nail (10) with a first (11) and a second (12) fixing end, furthermore, an aiming unit (20) containing a clamping device (21) suitable for gripping the first fixing end (11) of the intramedullary nail (10), as well as a supporting arm (22) connected to the clamping device (21) and a drill guide part-unit (23), the first fixing end (11) and the second fixing end (12) of the intramedullary nail (10) have locking bores (11a, 12a, 12b, 12c). The characteristic feature of the invention is that, it is supplemented with a guide structure (30) independent of the aiming unit (20), the guide structure (30) has a supporting element (31) with a handle (34) and a sleeve fixing body (32) connected to and protruding from the supporting element (31), the sleeve fixing body (32) has one or more aiming openings (32e) and in at least some of the aiming openings (32e) there are drill sleeves (40), furthermore, there is a first positioning body (13) in the vicinity of one of the locking bores (12a, 12c) arranged at the second fixing end (12) of the intramedullary nail (10), the supporting element (31) of the guide structure (30) has a second positioning body (33) that conforms to the form and size of the first positioning body (13), and when the first positioning body (13) and the second positioning body (33) are connected the longitudinal axis (41) of the first drill sleeve (40) of the guide structure (30) is coaxial with the axis (12aa) of the first locking bore (12a) positioned at the second fixing end (12) of the intramedullary nail (10).

Description

EQUIPMENT FOR THE FIXATION OF INTRAMEDULLARY NAILS

The subject of the invention relates to a set of equipment for the simplification of the fixing of intramedullary nails which contains an intramedullary nail with a first and a second fixing end, furthermore, an aiming unit containing a clamping device suitable for gripping the first fixing end of the intramedullary nail, as well as a supporting arm connected to the clamping device and a drill guide part-unit, the first fixing end and the second fixing end of the intramedullary nail have countersink holes.

For the fixing of the broken pieces of tubular bones, especially the tibia, into their original position intramedullary nails are frequently used, which with the help of locking screws are connected together with the pieces of the broken bone. Aiming devices are widely used for the preparation of the holes for the locking screws in the appropriate position. The essence of the known aiming devices is that they have a clamping part for the connecting of the intramedullary nail, and furthermore, one or more arms that can be connected to the clamping part that have guide sleeves that act as guides to the holes closer to the so-called "proximal" end of the intramedullary nail used clamped in the aiming device. Among others patent description registration number HU 191.355 and publication document number HU T/70.102 present such aiming devices.

However, for the appropriately precise holes to be prepared in the bone to be fixed, especially the bone holes that match the locking holes positioned in the so-called "distal" end of the intramedullary nail, . opposite to the end clamped in the aiming device, the aiming devices used today also demand the use of so-called "image intensifiers". The essence of this is that the positioning and fixing of the intramedullary nails takes place under the continuous monitoring and operation of a small sized X-ray device. An aiming device that co-operates with an image intensifier is presented by e.g. publication document number HU T/73.698.

The greatest disadvantage of such intramedullary nail fixation is that the radiation continuously emitted by the image intensifier during the operation can cause injury to the health of the patient, the surgeon and the auxiliary staff, which should be avoided by all means.

A further disadvantage is that during the preparation of the locking holes in order to prevent the undesired movements the aiming device is supplied with several arms, which makes the use and handling of the aiming device more difficult, what is more, this can lead to the unjustified increase of the duration of the operation.

Another of the disadvantages is that in the case of the use of complex aiming devices without an image intensifier appropriate bore arrangements are not always made, which makes the final fixation of the intramedullary nail extremely difficult. Due to this in places where there is no image intensifier available, the use of the aiming device itself does not solve the problem of attaining the desired drilling position precisely, and the situation of the doctor and the patient is made more difficult.

With the construction according to the invention our aim was to overcome the deficiencies of the known versions and to create a solution suitable for the positioning of intramedullary nails that can be used without the need for an image intensifier, is easy to use and with the help of which even the distal locking holes can be made with satisfactory precision, and which during the operation does not require the use of any special device or equipment.

The basis of the idea behind the invention was formed by the recognition that if we place one of the distal fixing holes at- the end of the intramedullary nail further away from the aiming device, at a suitably chosen place on the intramedullary nail that is less susceptible to deformation, which is simply used as an orientation base that can be found with the help of the aiming device, then in order to find further locking bores at this distant end during an operation we use a free moving drill guide device with a unique geometry that can be fitted to the newly created base, which is independent from the other parts of the aiming device, then the task can be solved.

In accordance with the set aim the invention is a set of equipment for the simplification of the fixing of intramedullary nails - which contains an intramedullary nail with a first and a second fixing end, furthermore, an aiming unit containing a clamping device suitable for gripping the first fixing end of the intramedullary nail, as well as a supporting arm connected to the clamping device and a drill guide part-unit, the first fixing end and the second fixing end of the intramedullary nail have locking bores - which is constructed in such a way that it is supplemented with a guide structure independent from the aiming unit, the guide structure has a supporting element with a handle and a sleeve fixing body connected to and protruding from the supporting element, the sleeve fixing body has one or more aiming openings and in at least some of the aiming openings there are drill sleeves, furthermore, there is a first positioning body in the vicinity of one of the locking bores arranged at the second fixing end of the intramedullary nail, the supporting element of the guide structure has a second positioning body that conforms to the form and size of the first positioning body, and when the first positioning body and the second positioning body are connected the longitudinal axis of the first drill sleeve of the guide structure is coaxial with the axis of the first locking bore positioned at the second fixing end of the intramedullary nail.

A further criterion of the set of equipment according to the invention may be that three locking bores are arranged at the second fixing end of the intramedullary nail, and the first positioning body is positioned in the vicinity of the intermediate locking bore surrounded by the first outer locking bore and the second outer locking bore.

In another different version of the set of equipment at the second fixing end of the intramedullary nail there is a supporting base, e.g. tabling, in the vicinity of at least one locking hole.

In a still different construction example of the invention the first positioning body is formed by an oval depression that expands the introductory opening of the intermediate locking bore positioned at the second fixing end of the intramedullary nail, and the second positioning body by an oval cross-section stem-part positioned in the vicinity of the first end of the supporting element of the guide structure. In a further form of the invention the sleeve fixing body of the guide structure contains a neck part connected to the supporting element and a head part with a main plane at an angle to the axis of the neck part between 60-120°, and the aiming openings are formed in the head part.

From the point of view of the set of equipment it may be favourable if the longitudinal axis of the second positioning body of the guide structure and the longitudinal axis of the drill sleeves are positioned at right angles to each other. The main axis of the supporting element of the guide structure and the longitudinal axis of the second positioning body are coaxial.

In another different construction example of the invention the distances between the longitudinal axes of the drill sleeves and the main axis of the supporting element are the same length.

The most important advantage of the set of equipment according to the invention is that due to the uniquely formed base bore positioned in the intramedullary nail and the guideless, new guide structure connected to it the locking bores required for the fixing of the distal end of the intramedullary nail can be made without an image intensifier, simply, with great precision in a short period of time.

A further advantage due to this is that the radiation dose to the patient, the doctors and the surgery assistants is terminated, so health damage does not occur.

Due to the easier use of the simpler aiming device the operation time is shortened, which, on the one hand, reduces the operation risk, and, on the other hand, with the moderation of the load on the patient it creates the possibility of quicker recovery.

Another advantage is that the new type of guide structure may be simply manufactured and assembled, it consists of a small number of components, so its pricing is favourable. As a consequence of the minimal number of components and the ability to disassemble it completely, the guide device can be cleaned and sterilised easily, so less well equipped hospitals and operating theatres are able to use it without difficulty.

Another favourable factor is that the intramedullary nails with the geometrical form used up till now in bone fixation can still be used, so from this point of view surgery technology does not require any sort of change. The distal end base can be made simply on the existing intramedullary nails.

In the following the invention is presented in detail in connection with construction examples on the basis of drawings. On the drawing

Figure 1 shows the intramedullary nail of the set of equipment according to the invention connected to the aiming unit in side view, Figure 2 shows the guide structure in side view in partial cross-section, Figure 3 is figure 2 in the direction III.

Figure 1 shows the intramedullary nail 10 belonging to the set of equipment according to the invention and the aiming unit 20. It can be observed that the aiming unit 20 - in the usual way contains a clamping device 21 for the clamping of the first fixing end 11 of the intramedullary nail 10, a supporting arm 22 and a drill guide part unit 23 on the end of the supporting arm 22 opposite the clamping device 21. The drill guide part unit 23 is suitable for making it possible to make holes in the bone - not shown on the figures - that match up to the locking holes 11a of the first fixing end 11 of the intramedullary nail 10.

At the second fixing end 12 of the intramedullary nail 10 opposite the first fixing end 11 clamped in the clamping device 21 of the aiming unit 20, in an arrangement and position with respect to each other that is known in itself, the first locking bore 12a, the second locking bore 12b and the intermediate locking bore 12c between these two can be found. It has to be mentioned here that it is not necessary for there to be three locking bores 12a, 12b, 12c at the second fixing end of the intramedullary nail 10. There are such versions in existence, e.g. in a intramedullary nail 10 for fixing arm bones, that have only two locking bores 12a and 12c at the second fixing end 12, and there are even cases where there are more than three locking bores 12a^ 12b, 12c.

However, in the case of the intramedullary nail 10 appearing in the construction example presented in figure 1 in the vicinity of the introductory opening 12cc of the intermediate locking bore 12c there is the tabling 14 as a supporting base at the second fixing end 12 of the intramedullary nail 10, while in the introductory opening 12cc of the intermediate locking bore 12c there is the first positioning body 13. In this realisation, the first positioning body 13 is an oval hole that expands the intermediate locking bore 12c. So in this version the intermediate locking bore 12c, the tabling 14 and the first positioning body together form the base for the second fixing end 12 of the intramedullary nail 10 to which the guide structure 30 that can be seen in figures 2 and 3 can be fitted. Here it also has to be noted that the first positioning body 13 can be other than an oval hole and the tabling 14 can also be replaced with another shape at the second fixing end 12.

It can be observed that the guide structure 30 includes the supporting element 31 and the sleeve fixing body 32 fixed to the supporting element 31. At the first end 31a of the supporting element 31 there is a stem-part 31b containing the second positioning body 33, while at the second end 3 Id of the supporting element 31 there is a handle 34 making the use of the guide structure 30 easier. In essence, in this version the second positioning body 33 in the stem-part 31b is a pin with a cross-section with a form matching the form and size of the first positioning body 13 with an oval cross-section. In the interest of simpler production and easier handling the main axis 31c of the supporting element 31, as well as the longitudinal axis 33a of the second positioning body 33 are coaxial.

On figures 2 and 3 it can also be easily seen that the sleeve fixing body 32 consists of a neck part 32a and a head part 32c. The head part 32c has two accepting openings 32e into which the drill sleeves 40 forming the first outer locking bore 12a and the second outer locking bore 12b of the second fixing end 12 of the intramedullary nail 10 can be fixed. The neck part 32a and the head part 32c of the sleeve fixing body 32 is bent from a single piece, and they are positioned with respect to one another so that the angle "α" between 60- 120° between the axis 32b of the neck part 32a and the main plane 32d of the head part 32c is favourably 90°.

As a consequence of this the longitudinal axis 33a of the second positioning body 33 on the supporting element 31 of the guide structure 30 and the longitudinal axes 41 of the drill sleeves 40 fitted into the accepting openings 32e of the head part 32c of the sleeve fixing body 32 are at right angles to one another.

As can be seen in figure 3 in this presented construction form the accepting openings 32e are positioned in the head part 32c of the sleeve fixing body 32 so that they are symmetrical to the longitudinal axis 33a of the second positioning body 33 of the supporting element 31. At this time the distances "T" between the longitudinal axis 33a of the second positioning body 33 and the longitudinal axes 41 are of equal length.

Figure 2 also shows that when the second positioning body 33 of the supporting body 31 of the guide structure 30 is positioned in the first positioning body 13 of the second fixing end 12 of the intramedullary nail 10, then the longitudinal axis 33a of the second positioning body 33 and the main axis 12d of the intermediate lock bore 12c in the second fixing end 12 of the intramedullary nail 10 coincide, the longitudinal axis 41 of the one drill sleeve 40 is coaxial with the axis 12aa of the one outer locking bore 12a of the second fixing end 12, while the longitudinal axis 41 of the other drill sleeve 40 is coaxial with the axis 12bb of the other outer locking bore 12b.

Here, however, we have to mention that the longitudinal axis 33a of the other positioning body 33 of the guide structure 30, and the longitudinal axes 41 of the drill sleeves 40 in the accepting openings 32e in the head part 32c of the sleeve fixing body 32, and, furthermore, the angle between the axis 32b of the neck part 32a of the sleeve fixing body 32 and the main plane 32d of the head part 32c, as well as the position of these with respect to each other may be different to those presented in connection with the figures, but it is essential that they coincide with the arrangement of the one outer locking bore 12a, the other out locking bore 12b and the intermediate locking bore 12c at the second fixing end 12 of the intramedullary nail 10. So it is a basic requirement that the axes that belong to one another on the second fixing end 12 and on the guide structure be coaxial in every case.

During the use of set of equipment according to the invention firstly the intramedullary nail 10 is fixed in the usual way to the clamping device 21 of the aiming unit 20, then the intramedullary nail 10 is routinely fitted into the medullary space of the broken bone. Following this with the help of a suitably selected device the bone bore falling in the main axis 12d of the intermediate locking bore 12c of the second fixing end 12 of the intramedullary nail 10 is made.

Via the opening made in this way the intermediate locking bore 12c of the second fixing end 12 of the intramedullary nail 10 becomes accessible. Fitting the supporting element 31 of the guide structure 30 into the introductory opening 12cc of the intermediate locking bore 12c the second positioning body 33 slips into the first positioning body 13, and in this position holds the guide structure 30 in position. The longitudinal axes 41 of the drill sleeves 40 firmly clamped into the sleeve fixing body 32 of the guide structure 30 coincide with the axis 12aa of the one outer locking bore 12a of the second fixing end 12 and the axis 12bb of the other outer locking bore 12b. In this positioned and temporary fixed position of the guide structure 30 the bores made in the bone through the drill sleeves 40 lead precisely through the one outer locking bore 12a and the other outer locking bore 12b. Following the preparation of the bores the second fixing end 12 of the intramedullary nail 10 may be fixed to the broken bone.

The invention can be used efficiently for the simple and fast fixing of the distal end of intramedullary nails to broken bones without the assistance of image intensifiers. List of references

0 intramedullary nail 11 first fixing end 11a locking holes

12 second fixing end

12a locking bore (one outer)

12aa axis

12b locking bore (other outer)

12bb axis

12c locking bore (intermediate)

12cc introductory opening

12d main axis

13 first positioning body

14 supporting base 0 aiming unit 21 clamping device

22 supporting arm

23 drill guide part unit 0 guide structure 31 supporting element 3 la first end

3 lb stem-part 31c main axis 3 Id second end

32 sleeve fixing body 32a neck part

32b axis

32c head part

32d main plane

32e accepting opening

33 second positioning body 33a longitudinal axis

34 handle

40 drill sleeves 41 longitudinal axes "T" distance "α" angle

Claims

1. A set of equipment for the simplification of the fixing of intramedullary nails which contains an intramedullary nail (10) with a first fixing end (11) and a second fixing end (12), furthermore, an aiming unit (20) containing a clamping device (21) suitable for gripping the first fixing end (11) of the intramedullary nail (10), as well as a supporting arm (22) connected to the clamping device (21) and a drill guide part-unit (23), the first fixing end (11) and the second fixing end (12) of the intramedullary nail (10) have locking bores (11a, 12a, 12b, 12c), characterised by that it is supplemented with a guide structure

(30) independent of the aiming unit (20), the guide structure (30) has a supporting element

(31) with a handle (34) and a sleeve fixing body (32) connected to and protruding from the supporting element (31), the sleeve fixing body (32) has one or more aiming openings (32e) and in at least some of the aiming openings (32e) there are drill sleeves (40), furthermore, there is a first positioning body (13) in the vicinity of one of the locking bores (12a, 12c) arranged at the second fixing end (12) of the intramedullary nail (10), the supporting element (31) of the guide structure (30) has a second positioning body (33) that conforms to the form and size of the first positioning body (13), and when the first positioning body (13) and the second positioning body (33) are connected the longitudinal axis (41) of the first drill sleeve (40) of the guide structure (30) is coaxial with the axis (12aa) of the first locking bore (12a) positioned at the second fixing end (12) of the intramedullary nail (10).

2. The set of equipment according to claim 1 characterised by that three locking bores (12a, 12b, 12c) are arranged at the second fixing end (12) of the intramedullary nail (10), and the first positioning body (13) is positioned in the vicinity of the intermediate locking bore (12c) surrounded by the first outer locking bore (12a) and the second outer locking bore (12b).

3. The set of equipment according to claim 1 or 2 characterised by that at the second fixing end (12) of the intramedullary nail (10) there is a supporting base (14), e.g. tabling, in the vicinity of at least one locking bore (12c).

4. The set of equipment according to any of claims 1-3 characterised by that the first positioning body (13) is formed by an oval hole that expands the introductory opening (12cc) of the intermediate locking bore (12c) positioned at the second fixing end (12) of the intramedullary nail (10), and the second positioning body (33) by an oval cross-section stem-part (31b) positioned in the vicinity of the first end (31) of the supporting element (31) of the guide structure (30).

5. The set of equipment according to any of claims 1-4 characterised by that the sleeve fixing body (32) of the guide structure (30) contains a neck part (32a) connected to the supporting element (31) and a head part (32c) with a main plane (32d) at an angle (α) to the axis (32b) of the neck part (32a) between 60-120°, and the aiming openings (32e) are formed in the head part (32c).

6. The set of equipment according to any of claims 1-5 characterised by that the longitudinal axis (33a) of the second positioning body (33) of the guide structure (30) and the longitudinal axis (41) of the drill sleeves (40) are positioned at right angles to each other.

7. The set of equipment according to any of claims 1-6 characterised by that the main axis (31c) of the supporting element (31) of the guide structure (30) and the longitudinal axis (33a) of the second positioning body (33) are coaxial.

8. The set of equipment according to any of claims 1-7 characterised by that the distances (T) between the longitudinal axes (41) of the drill sleeves (40) and the main axis (31c) of the supporting element (31) are the same length.