DE29910202U1 - Packing material for narrowing the cross section of a bone canal - Google Patents

Description

&Aacgr; 55 054 U Aesoulap AG & Co. KG

u - 223/234 Am Aesculap Platz

9 June 1999 78532 Tuttlingen

Filler for narrowing the cross-section of a bone canal

The invention relates to a filling body for narrowing the cross-section of a bone canal.

When cruciate ligament replacement transplants are implanted, these transplants are inserted into a bone canal and only partially fill its cross-section after insertion. As a result, when the joint moves, a relative movement can occur between the transplant and the surrounding bone material, and this relative movement can in some cases lead to an enlargement of the bone canal and damage to the transplant.

The object of the invention is to create a filling body for narrowing the cross-section of a bone canal, which on the one hand can be easily inserted into the bone canal and which on the other hand narrows the cross-section of the bone canal after the insertion of a transplant so that the transplant can be fixed in a defined manner in the bone canal.

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This object is achieved according to the invention with a filling body of the type described at the beginning in that it is a hollow body in the shape of a tube that is open on one side. Such a hollow body can be inserted very advantageously into the free space of the bone canal in the manner of a suppository and, due to its hollow body shape, offers the possibility of filling it with bone material so that this filled bone material can grow together with the surrounding bone material and thus leads to a permanent narrowing of the bone canal.

It is particularly advantageous if openings are arranged in the side wall of the hollow body. Through these openings, the bone material can grow together with the surrounding bone, and the resulting bony bridges lead to a rapid bony narrowing of the bone canal with optimal fixation of the transplant.

It is advantageous if the filling body tapers on its closed side, especially in the form of a conical tip. This makes it particularly easy to insert into the bone canal without the risk of damaging the implanted transplant.

In a preferred embodiment, a thread-like pulling element is arranged on the closed side of a filling body. This pulling element can be guided through the bone canal and then makes it possible to pull the filling body into the bone canal simply by pulling. In this way

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Such a filling body can be drawn into a bone canal even in very difficult to access places, for example in the knee joint.

The pulling element can, for example, be guided through a retaining eyelet at the closed end of the hollow body; it is also possible for the pulling element to be guided through at least one opening at the closed end of the hollow body.

The filling body can preferably have a circular cross-section, but it is also within the scope of the invention to choose other cross-sectional shapes, for example an oval cross-sectional shape.

It is particularly advantageous if the filler consists of a biocompatible material, in particular a biocompatible metal. Such a filler material can grow particularly well with the body's own tissue because it is not rejected by the latter.

It is advantageous if the filler consists of a resorbable material, in particular a resorbable ceramic. In this way, the filler dissolves over time and the narrowing of the bone canal is then brought about exclusively by the bone material that is introduced into the bone canal inside the filler and, over time, bonds with the surrounding bone material.

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The outer diameter of the filler can be, for example, between 3 mm and 6 mm, in particular between 4 mm and 5 mm.

The length of the packing is, for example, between 12 mm and 25 mm, in particular between 15 mm and 20 mm.

The following description of preferred embodiments of the invention serves to explain in more detail in conjunction with the drawing. They show:

Figure 1: a schematic side view of a knee joint with a bone canal for receiving a cruciate ligament transplant and with two inserted filling bodies;

Figure 2: a side view of a filling body with a pulling thread guided through a retaining eyelet;

Figure 3: a side view of the filling body of Figure 2 after a rotation about the longitudinal axis by 90°;

Figure 4: a view of the packing of Figure 2 in the direction of arrow A;

Figure 5: a view similar to Figure 4 of a packing body with oval cross-section and

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Figure 6: a side view of a modified filling body, shown partially broken away, with an opening at the free end for the passage of a pulling thread.

In the area of a joint 1, an essentially continuous bone channel 4 is incorporated into the bones 2, 3 forming the joint, for example by drilling. A band-shaped transplant 5 is inserted into this bone channel 4, which ends at its free ends in bone pieces 6, 7 that are inserted into the bone channel 4. Tension threads 8, 9 engage the bone pieces 6 and 7, which are held on plate-shaped implants 10, 11 that are attached to the outside of the bones and cover the bone channel 4, thereby keeping the transplant 5 under the desired tension.

The transplant 5 has a cross-section that is significantly smaller than the cross-section of the bone canal 4, and in the remaining free space in both bones 2, 3, filling bodies 12 are inserted, which are formed by hollow bodies in the shape of a tubular piece that are open on one side and closed at one end 13. At this closed end 13, the filling body 12 preferably tapers somewhat conically, so that the filling body 12 as a whole takes on the shape of a suppository or a bullet.

In the side wall 14 of the filling body 12 there are a large number of window-like openings

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15, and in the area of the closed end 13, in the embodiment of Figures 1 to 4, an eyelet 16 is formed through which a pull thread 17 is passed. In the embodiment of Figure 6, such an eyelet 16 is missing, but a pull thread 17 passes through an opening 18 on the front side and is secured inside the filling body 12, for example by a knot.

The filling bodies 12 can have different cross-sections, for example a circular cross-section (Figure 4) or an oval cross-section (Figure 5), their outer diameter is between 2 mm and 6 mm, in particular between 4 mm and 5 mm, their length between 10 mm and 25 mm, in particular between 15 mm and 20 mm. Any biocompatible material can be used to produce the filling bodies 12, but it is advantageous to use resorbable plastic or, even better, resorbable ceramic materials.

The filling bodies 12 can be inserted in a simple manner using the pulling threads 17, which are laid through the bone canal 4 and emerge from it on the side opposite the insertion side, so that from there the filling body 12 can be drawn into the bone canal by pulling on the pulling thread 17. In doing so, it fills the space between the wall of the bone canal 4 on the one hand and the transplant 5 on the other hand; with appropriate dimensions, the transplant 5 can even be fixed in a clamped fit in the bone canal. Before drawing in

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of a filling body 12, the interior of the same, which is open on one side, is filled with bone material so that after being drawn in, bone material can come into contact with the wall of the bone canal 4 through the window-like openings 15. In this way, bony bridges and growths are quickly formed so that the empty space of the bone canal is filled with bone in the long term. This is especially true if the filling body 12 is made of resorbable material and dissolves over time.

In the embodiment shown in Figure 1, the transplant 5 is fixed in the bone canal 4 using pieces of bone 6 and 7. In modified methods, these pieces of bone 6, 7 are missing, in these cases the transplants 5 are connected to the implants and 11 exclusively by the tension threads 8 and 9, and then it is particularly advantageous if the filler bodies 12 fill the remaining cross-section of the bone canal 4, in these cases the filler bodies 12 can also be drawn deeper into the bone canal 4 than is shown in the illustration in Figure 1.

Claims (14)

A 55 054 u 9 June 1999 u-223/234 PROTECTION CLAIMS 1. Filling body for narrowing the cross-section of a bone canal, characterized in that it is a tubular hollow body that is open on one side. 2. Filling body according to claim 1, characterized in that openings (15) are arranged in the side wall (14) of the hollow body. 3. Filling body according to claim 1 or 2, characterized in that it tapers on its closed side (13). 4. Filling body according to one of the preceding claims, characterized in that a thread-like tension element (17) is arranged on the closed side (13). 5. Filling body according to claim 4, characterized in that the tension element (17) is guided through a retaining eyelet (16) at the closed end (13) of the hollow body. A 55 054 u
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u-223/234 6. Filling body according to claim 4, characterized in that the tension element (17) is guided through at least one opening (18) at the closed end (13) of the hollow body. 7. Filling body according to one of the preceding claims, characterized in that it has a circular cross-section. 8. Filling body according to one of claims 1 to 6, characterized in that it has an oval cross-section. 9. Filling body according to one of the preceding claims, characterized in that it consists of a biocompatible material. 10. Filling body according to claim 9, characterized in that the biocompatible material is a metal. 11. Filling body according to one of claims 1 to 9, characterized in that it consists of resorbable material. - 10 - A 55 054 u
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u-223/234 12. Filling body according to claim 11, characterized in that the resorbable material is a ceramic. 13. Filling body according to one of the preceding claims, characterized in that its outer diameter is between 3 mm and 6 mm. 14. Filling body according to one of the preceding claims, characterized in that its length is between 12 mm and 25 mm.