WO1996041595A1 - Process and device for the culture of bone replacement material - Google Patents

Abstract

A process for the culture of bone replacement material, in which a bone recess freed of periostium is covered from the soft tissue surrounding the bone by a device which can be secured to the bone and has a covering membrane preferably consisting of biodegradable material, whereupon bone can grow from the bone in such a culture chamber, in which a region of a concave bone, especially the pelvic bone, differing from the final point of use of the bone replacement material is selected as the bone hollow; the periostium is removed from the bone in the selected region; the bone within the selected region is opened, especially drilled, at at least one point to provide a bleedale connection between the bone tissue and the bone hollow defined by the selected region; the covering device is then secured to the bone to cover the bone hollow; the periostium and neighbouring soft tissue is applied to the covering device; after the growth of the bone material into the culture chamber the covering device is released; the covering device and the cultured bone replacement material is removed from the bone hollow; and finally the cultured bone replacement material is inserted into a bone recess to be finally filled therewith. The invention also relates to a device for the implementation of this process.

Description

 Method and device for growing bone substitute material

description

The invention relates to a method for growing bone substitute material, in which a bone cavity freed from periosteum is covered by means of a covering device having a covering membrane, preferably made of biodegradable material, which can be fastened to the bone and is covered with respect to the soft tissue surrounding the bone , whereupon a breeding chamber thus created will grow through the bone from the bone, and a device for carrying out this method.

It is known to fill bone recesses, which arise, for example, from surgical treatments, with bone material by introducing, for example, synthetic bone-building material, in particular based on hydroxyapatite, into the bone recess in question, which is then used by the patient at the place of use hitting the bones from the bone. In particular, the procedure is such that the corresponding bone recess is covered against the surrounding soft tissue by means of a covering device, the covering device serving the purpose of protecting the bone recess against mechanical loads in order to prevent undisturbed bony growth of the bone building material guarantee, but also the purpose has to cover the bone recess in a substantially liquid-tight manner against the surrounding soft tissue in order to prevent the bone from growing in without bone. For this purpose, covering devices such as covering membranes and the like are known, as are described, for example, in DE-OS 44 14 675, DE-OS 44 18 159, DE-PS 43 02 708 and DE-PS 43 02 709. The covering devices can be attached to the bone by means of fastening nails, to name just one example, as they are mentioned, for example, in DE-PS 43 00 039.

The procedures described above have proven their worth. However, there is a difficulty that it is difficult, particularly in the case of serious bone diseases with correspondingly large bone defects, to ensure a satisfactory bony growth of the bone recess with new bone replacement material on site in a sufficiently short time. Attempts have therefore already been made to use synthetic bone replacement material, appropriately shaped, but the healing properties leave something to be desired. Another possibility is to remove the body's own bones from a location remote from the actual place of use, e.g. from the pelvic bone, but this naturally requires substantial bone surgery.

The object of the invention is to create a method and a device of the generic type which ensure faster and better osseous filling of bone defects.

According to the invention, this object is achieved in a further development of the generic method in that the bone cavity is one of the final place of use of the Bone replacement material from different areas of a concavely curved bone, in particular the pelvic bone, is selected; that the periosteum is detached from the bone in the selected area; that the bone is opened, in particular drilled, at least at one point within the selected area to produce a bleeding connection between the bone tissue and the bone cavity defined by the selected area; that the covering device is then attached to the bone while covering the bone cavity; that the periosteum along with adjacent soft tissue is then brought into contact with the covering device; that after the ingrowth of the bone material in the growth chamber, the covering device is exposed; that the covering device and the grown bone substitute material are then removed from the bone cavity; and that finally the cultured bone substitute material is inserted into a bone recess to be finally filled with it.

It can be provided that a support grid covered with the cover membrane, such as perforated titanium sheet, titanium grid or the like, is used as the covering device.

The invention also proposes that the covering device be at least partially inserted into the bone with its peripheral edge and thereby fastened to the bone.

According to the invention it can also be provided that the bone surface facing the growth chamber is covered with a separating grid, such as perforated titanium sheet or the like. A further embodiment of the invention provides that the separating grid is mechanically firmly connected to the peripheral edge of the covering device to form a breeding capsule containing the breeding chamber; and that the removal of the cultured bone substitute material from the bone cavity is accomplished by removing the growth capsule formed from the covering device and the separating grid.

It can be provided that the growth chamber is shaped in accordance with the anatomical requirements at the final place of use of the bone replacement material to be grown, and is preferably designed to be convex at least with respect to the bone cavity.

Furthermore, the invention provides that the region of the bone, which is possibly only provisionally selected, is initially covered with an essentially rigid template, such as titanium sheet template or the like, which corresponds to the shape of the covering device to be used later and which has at least three centering bores for receiving Has centering pins; that then, if necessary after optimizing the position of the template to the shape of the bone, centering pins are introduced into the bone through the centering holes, which protrude beyond the template on the side facing away from the bone; that the template is then removed; that instead of the template, the cover device adapted to its shape is placed on the bone, the cover device being centered by the centering pins which engage in the centering holes of the template; and that the covering device is then attached to the bone.

According to the invention, it is provided that the loading the cover device is fixed by means of fastening rings or caps which can be placed on the ends of the centering pins which pass through the guide openings.

It can be provided that the fastening rings or caps are glued to the centering pin.

The invention also proposes that the mounting rings or caps are welded to the centering pins.

Another embodiment of the invention proposes that the fastening rings or caps are screwed to the centering pins.

It is provided according to the invention that centering pins made of biodegradable material, such as polylactide or the like, are used.

The device according to the invention for carrying out the method, with a covering device, preferably having a covering membrane consisting of biodegradable material, which can be fastened to the peripheral edge of a bone cavity, is characterized in that the covering device is directed towards the area surrounding the bone cavity Bone has bent inlet edge.

Furthermore, the device according to the invention for carrying out the method can be characterized by a separating grid, such as perforated titanium sheet or the like, which can be mechanically connected to the peripheral edge of the covering device.

The invention is further characterized by a template corresponding to the shape of the covering device for receiving centering pins, the covering device has guide openings corresponding to the centering bores.

According to the invention it is also provided that the centering pins consist of biodegradable material.

Another embodiment of the invention provides that the covering device can be fastened to the bone by means of fastening rings or caps that can be attached to the centering pins.

It can be provided that the fastening rings or caps can be glued to the centering pins.

Furthermore, the invention provides that the fastening rings or caps can be welded to the centering pins.

Finally, the invention also provides that the fastening rings or caps can be screwed to the centering pins.

The invention is based on the surprising finding that it is possible to provide a sufficient amount of bone substitute material produced by the body's own bone substitute material without undue intervention in the place of use of the bone substitute material, by placing it in one place in a bone cavity, so to speak, of course is cultivated, which does not cause discomfort to the person to be treated. The inner cavity of the pelvic bone is particularly suitable for this, since here the growth chamber to be formed is already limited on one side by a concave surface, namely the inner surface of the pelvic bone. A breeding chamber can then be formed by means of the covering device, which interfered with growth of bone substitute material in a period of, for example, six to eight months. By cleverly shaping the covering device it can be achieved that the grown bone replacement material already largely corresponds to the shape of the bone recess, for example in a jaw bone, which is later to be filled with the bone replacement material.

Further features and advantages of the invention result from the following description, in which exemplary embodiments are explained in detail with reference to the schematic drawing.

It shows:

1 shows an embodiment of a template that can be used in the device according to the invention in contact with a pelvic bone in plan view;

FIG. 2 shows the template from FIG. 1 in an enlarged illustration, likewise in a plan view corresponding to FIG. 1;

3 shows a section along the line III -

III of Fig. 2;

4 shows a section corresponding to FIG. 3 through a covering device of a device according to the invention;

5 shows a section corresponding to FIG. 4 through an exemplary embodiment of a covering device according to the invention on an enlarged scale;

6 shows a section corresponding to FIG. 4 through a modified exemplary embodiment of a covering device according to the invention; and

7 a section corresponding to FIG. 6 through a further embodiment a covering device according to the invention.

As shown in FIG. 1, a template 12, made of curved titanium sheet, is placed there on the concave inner surface of a pelvic bone 10 facing the front of the body. It is temporarily held on the pelvic bone 10 by three centering pins 14, 16, 18, which are made of biodegradable material, namely polylactide in the exemplary embodiment shown, and in bores previously made in the pelvic bones 10, which will be explained in more detail below are let in.

Fig. 2 shows the relationships shown in Fig. 1 on an enlarged scale. It can be seen in particular that the template 12 is shaped in accordance with the curvature of a jawbone, as can also be seen from the sectional view according to FIG. 3.

3 shows that a fastening hole 20 has been made in the pelvic bone 10, into which the centering pin 16 is inserted. The template 12 has a centering bore 22, through which the centering pin 16 projects, with its free end located above in FIG. 3 projecting over the template 12.

3 shows how, instead of the template 12 from FIG. 3, a cover device 24, which is curved and shaped in accordance with the template, is placed on the pelvic bone 10 and has a guide opening 26 which is penetrated by the centering pin 16. A fastening cap 28 is glued onto the end of the centering pin 16 facing away from the pelvic bone 10, which cap, together with the further centering pins etc. 1 and 2 are shown, on which pelvic bone 10 holds firmly. The cover device 24 has a support grid 30 made of titanium sheet and a continuous cover membrane 32 made of biodegradable material, namely polylactide, reference being made to DE-OS 44 14 675 for further explanation because of the structure of the cover device 24 in this regard reference is made in its entirety to the additional description of the invention. A growth chamber 34 formed by the pelvic bone 10 and by the covering device 24 is already filled with ingrown bone substitute material 36 in FIG. 4.

Fig. 5 shows the cover device 24 of Fig. 4 in an enlarged view with webs 38, 40 of the support grid 30. The cover membrane 32 is with the support grid 30 e.g. glued or welded or in the manner known from DE-OS 44 14 675 generated in situ on the support grid.

The method according to the invention is carried out, for example, using the device elements according to FIGS. 1 to 5 as follows:

First, in a rough adaptation to the shape of a bone recess that is present at another part of the body and is to be filled with bone substitute material, for example for the treatment of a bone defect in the jaw bone, a template 12 is formed from titanium sheet or selected from a larger supply of sample templates. The concave inner surface of the pelvic bone 10 is then surgically exposed in some areas, the periosteum being lifted off. The pelvic bone 10 is then damaged in the selected area to be covered by the template 12, for example by making small bores, so that bleeding occurs from the inside of the pelvic bone 10 into the area to be covered later by the covering device 24, ie into the growth chamber 34 (FIG. 4). The stencil 12 is arranged on the concave inner surface of the pelvic bone 10 by gently pushing it back and forth in such a way that the peripheral edge of the convexly curved stencil 12 facing the pelvic bone 10 optimally contacts the inner surface of the pelvic bone 10 results. Then the fastening holes 20 are introduced into the pelvic bones 10 through the centering bores 22 provided in the template, whereupon the centering pins 14, 16, 18 are let into the fastening bores 20 which have been produced in the pelvic bones 10. The template 12 is then removed, so that the three centering pins 14, 16, 18 now protrude from the pelvic bone 10.

Then, the covering device 24 shaped according to the template 12 is placed on the pelvic bone 10 in the selected area instead of the template 12, the centering pins 14, 16, 18 ensuring optimal positioning and centering of the covering device 24. It should be noted here that the cover membrane 32 may advantageously be located on the inside of the support grid 30 of the cover device 24 facing the support grid 30 instead of on the outside selected in FIG. 4, that is to say on the side facing away from the pelvic bone 10 . After the covering device 24 has been positioned, a fastening cap 28 is placed on each of the centering pins 14, 16, 18 passing through the guide openings 26 of the covering device 24 and, in the exemplary embodiment shown, glued to the relevant centering pin. By means of the centering pins 14, 16, 18 and the corresponding fastening caps 28, the covering device 24 is now firmly attached in the manner attached to the pelvic bone 10 that the breeding chamber 34 compared to the surrounding soft tissue to be thought of in FIG. 4, in particular the previously detached periosteum, which is now brought into contact with the covering device 24 again with the remaining soft tissue against the Soft tissue is essentially liquid-impermeable, so that non-osseous ingrowth of soft tissue into the growth chamber 34 is prevented. Over the course of about six to eight months, the bone replacement material 36 now grows in the breeding chamber 34, which, due to the meaningful shape of the covering device 24, roughly corresponds to the shape of a bone recess, for example in the jaw bone, which is to be filled with the bone replacement material .

After the aforementioned period has elapsed, the surgeon removes the covering device 24 together with the grown bone replacement material 36, the centering pins 14, 16, 18, since they consist of biodegradable material, can remain in the pelvic bone if necessary. Then the bone substitute material 36 is used in the usual way to fill a bone recess to be treated, wherein a covering device, preferably consisting of a support grid and covering membrane, can be used again, as is the case, for example, in DE-OS 44 14 675 is known. The treatment is particularly favorable because the bone substitute material already has approximately the shape of the bone to be treated, so that practically only joints or relatively small areas have to be re-grown with bone material, granular material being used for this purpose if necessary Bone replacement material of synthetic form, in particular based on hydroxylapatite, can be used in a known manner.

In the embodiment shown in FIG. 6, the Cover device 24, here also consisting of support grid 30 and cover membrane 32, in this case attached to the inner surface of support grid 30 facing cultivation chamber 34, has a circumferential inlet edge 42 bent in the direction of pelvic bone 10, which leads into a corresponding groove of the pelvic bone 10, which was previously milled in by the surgeon, is embedded. As a result, the cultivation chamber 34 is closed particularly reliably with respect to the surrounding soft tissue, as a result of which perfect growth and cultivation of the bone replacement material 36 is promoted.

In the exemplary embodiment in FIG. 7, a separating grid 42, which, like the support grid 30, can be made of titanium sheet, bears against the inner surface of the pelvic bone 10 facing the growth chamber 34. The peripheral edge of the separating grid 42 is mechanically firmly connected to the peripheral edge of the concavely shaped supporting grid 30 of the covering device 24. In this way, the cover device 24 and the separating grid 42 form a cultivation chamber 34 which is "mechanically" closed on all sides, but from the pelvic bone 10 through the grid openings of the separating grid 42, which currently has no covering membrane, to Growth of the bone replacement material 36 necessary bleeding is guaranteed. As soon as the bone replacement material 36 has been grown, the entire capsule, which consists of the separating grid 42 and the covering device 24, is detached from the pelvic bone 10. The particular advantage here is that the separating grid 42 can be used as a guide for a surgical tool, such as a chisel or the like, so that the grown bone replacement material 36 can be detached from the pelvic bone 10 in a particularly gentle manner.

It should also be noted that the covering device 24 naturally Loan also in other ways than can be attached to the pelvic bone 10 by means of the fastening caps 20 placed on the centering pins 14, 16, 18, in particular if no template 12 is used at all. In this case, the covering device 24 can be fastened, for example, in the manner known from DE-PS 43 00 039 by means of corresponding fastening nails or the like.

The features of the invention disclosed in the above description, in the drawing and in the claims can be essential both individually and in any combination for realizing the invention in its various embodiments.

Claims

claims 1. A method for cultivating bone substitute material, in which a bone cavity freed from periosteum is covered by means of a covering device, preferably made of biodegradable material, which can be fastened to the bone and is covered with the soft tissue surrounding the bone, whereupon a breeding chamber thus created Bone is grown through from the bone, characterized in that a region of a concavely curved bone, in particular the pelvic bone, different from the final place of use of the bone substitute material, in particular the pelvic bone, is selected as the bone cavity; that the periosteum is detached from the bone in the selected area; that the bone within the selected area is opened, in particular drilled, at least at one point in order to produce a bleeding connection between the bone tissue and the bone cavity defined by the selected area; that the covering device is then attached to the bone while covering the bone cavity; that the periosteum and adjacent soft tissue are then brought into contact with the covering device; that after the bone material has grown into the growth chamber, the covering device is exposed; that the covering device and the grown bone substitute material are then removed from the bone cavity; and that the cultured bone substitute material is finally inserted into a bone recess to be filled with it. 2. The method according to claim 1, characterized in that as a covering device covered with the covering membrane supporting grid, such as perforated titanium sheet, titanium grid or the like, is used. 3. The method according to claim 1 or 2, characterized gekennzeich¬ net that the covering device with its peripheral edge at least partially embedded in the bone and thereby attached to the bone. 4. The method according to any one of the preceding claims, characterized in that the bone surface facing the growth chamber is covered with a separating grid, such as perforated titanium sheet or the like. 5. The method according to claim 4, characterized in that the separating grid is mechanically fixed to the peripheral edge of the cover device to form a breeding capsule containing the breeding chamber; and that the removal of the cultured bone substitute material from the bone cavity is accomplished by removing the growth capsule formed from the covering device and the separating grid. 6. The method according to any one of the preceding claims, characterized in that the growth chamber is shaped in accordance with the anatomical requirements at the final place of use of the bone substitute material to be grown, preferably convex at least with respect to the bone cavity. 7. The method according to any one of the preceding claims, characterized in that the region of the bone, which may only have been provisionally selected, initially with an essentially rigid template corresponding to the shape of the cover device to be used later, such as titanium sheet template or the like, is covered, the min at least has three centering bores for receiving centering pins; that then, if necessary after optimizing the position of the template to the shape of the bone, centering pins are introduced into the bone through the centering bores, which protrude beyond the template on the side facing away from the bone, - that the template then is removed; that instead of the template, the cover device adapted to its shape is placed on the bone, the cover device being centered by the centering pins which engage in the centering holes of the template; and that the covering device is then attached to the bone. 8. The method according to claim 7, characterized in that the fastening of the cover means by means of the ends of the centering pins passing through the guide openings attachable mounting rings or caps. 9. The method according to claim 8, characterized in that the fastening rings or caps are glued to the centering pin. 10. The method according to claim 8, characterized in that the fastening rings or caps are welded to the centering pins. 11. The method according to claim 8, characterized in that the fastening rings or caps are screwed to the centering pins. 12. The method according to any one of claims 7 to 11, characterized in that centering pins made of biodegradable material, such as polylactide or the like, are used. 13. Device for carrying out the method according to one of the preceding claims, with a covering device, preferably consisting of biodegradable material, comprising covering membrane which can be fastened to the peripheral edge of a bone cavity, characterized in that the covering device (24) has a direction towards the bone cavity surrounding bone (10) bent inlet edge (42). 14. Device for carrying out the method according to any one of claims 1 to 12, with a covering membrane, preferably consisting of biodegradable material, which can be attached to the peripheral edge of a bone cavity, in particular according to claim 13, characterized by a covering edge with the peripheral edge of the covering device (24) mechanically firmly connectable separating grid (44), such as perforated titanium sheet or the like. 15. Device according to claim 13 or 14, characterized by a template (12) corresponding to the shape of the covering device (24) for receiving centering pins (14, 16. 18), the covering device (24) having guide openings (26) corresponding to the centering bores (22). 16. The apparatus according to claim 15, characterized in that the centering pins (14, 16, 18) consist of biodegradable material. 17. The apparatus of claim 15 or 16, characterized gekenn¬ characterized in that the covering device (24) by means of the centering pins (14, 16, 18) attachable fastening rings or caps (28) can be fastened to the bone (10). 18. The apparatus according to claim 17, characterized in that the fastening rings or caps (28) can be glued to the centering pins (14, 16, 18). 19. The apparatus according to claim 17, characterized in that the fastening rings or caps (28) with the Zen¬ trierstifte (14, 16, 18) are weldable. 20. The apparatus according to claim 17, characterized in that the fastening rings or caps (28) with the Zen¬ trierstifte (14, 16, 18) can be screwed.