DE3704089A1 - Heterologous implant - Google Patents

Abstract

There is described a heterologous implant which is provided with a channel system starting at a receiving means with outlet openings distributed over the surface of the implant. After insertion of the implant into a body the tissue surrounding the implant can be repeatedly supplied transcutaneously with active substances, for example, growth factors, medicaments, hormones or the like.

Description

The invention relates to a heterologous implant, for example an endoprosthesis. With such implants made of metal, can be made from ceramic or from hydroxyapatite, Very often the problem arises that after the implantation surrounding tissues are not in the desired and required Way grown together with the implant and a stable relationship of living tissue with non-living materials. It is also disadvantageous that heterologous implants in the course of Can relax time, so that a replacement and thus a new one Surgery becomes necessary. This can be caused by micro movements of the implant apply, which reverses an atrophy of the implant effecting tissue.

To prevent the implant from loosening, an attempt is made to to stop the atrophy of tissues and cells. This he follows with the help of so-called growth factors. Your most important Property is that they have specific cell types specific to the cell can stimulate division and proliferation. The one with the best under The growth factor is the platlet derived growth factor (PDGF), which on mesenchymal connective tissue cells such as fibroblasts, Osteoblasts, glial cells and similar mitogen and stimulated this to growth. PDGF also has chemotactic properties because it is the only substance known to date is to get the otherwise relatively sluggish fibroblasts towards the location of the highest concentration of the growth factor spread out. PDGF is effective in very low concentrations.

The use of porous impregnated with growth factors Materials such as hydroxyapatite or ceramic as Bone replacement is known. The growth factor is supposed to be the bones promote new growth and rapid growth.

One disadvantage of such an impregnation is that  that the growth factor is broken down too quickly. Because of the low half-life, which in PDGF is only about two minutes is therefore the growth-promoting effect on one Time immediately after the operation is limited, so that the Atrophy can only be counteracted temporarily. In contrast, the growth factor is permanent on the implan did so, this could be due to a possible duration stimulation lead to excessive tissue growth.

The invention has for its object an implant Specify the type mentioned at the beginning, in which the new formation of the surrounding tissue intensifies and the atrophy becomes more effective is stopped. This problem is solved in that the Implant with at least one of an associated one Recording device outgoing channel system with the Im distributed outlet openings is provided.

The invention has the advantage that even after the onset of Implant into the organism by transcutaneous injection of a growth factor dissolved in a carrier medium into the channel system and simply by forwarding it to the tissue subsequent supply of growth factors is feasible. A new operation is not necessary. The injek tion can be repeated with a cannula at any time and as often as required surgery. In contrast to permanent impregnation The dose of the growth factor can be the current one Situation to be adjusted. The duct system creates the possibility ability to distribute the growth factor in a targeted manner.

Another advantage of the invention is that the Antibiotics are equally supplied around the implant if necessary. Here too can the dosage and the time of application without significant Impairment of the patient because there is only one  transcutaneous injection into the receiving device of the implant must be carried out.

In addition, the invention is also very well suited to Hor mones, such as estrogens, so that the mine Ralization of the bones can be promoted. As another sub punch, which is dissolved in the body-compatible liquid carrier medium medication can be considered. Furthermore, by Injection of a contrast medium repeats the progression of the Healing process and the waxing process with the help be monitored by an x-ray device.

The growth factors, antibiotics, Medications, hormones and contrast agents are listed below briefly referred to as active substances.

A preferred development of the invention is that several reception facilities and associated duct systems are present and that the associated outlet openings in different surface areas of the implant are arranged. In this way, different tissue regions targeted treatment independently. This can prove to be advantageous, for example, if at be agreed prosthesis forms from experience it is known that the Ver bond between animate and inanimate tissue in certain Regions is particularly critical.

Another embodiment of the invention is that the Reception facility by at least one raised approach mar is. The recording device can thus be used for an x-ray Illumination clearly localized and the cannula precisely attached be set.

In particular, it is advantageous that the receiving device as Stutzen is formed, the outline of which is clearly a localization allows. Further configurations of the receiving device are shown in Subclaims laid down.  

A particularly preferred embodiment of the invention exists in that the receiving device releasably with the rest of the Im plantate is connected. Thus, the receiving device can be removed from the organism when the rest of the implant is closed is connected peacefully with the surrounding tissue.

This releasable connection is preferably produced in that the implant at the entrance to the canal system with an internal thread and the receiving device with a corresponding external thread de is provided. The first when inserting the implant in the organism can be screwed to this receiving device unscrewed and removed in a relatively simple procedure if there is no further supply of active substances seems necessary.

To prevent any microorganisms from entering Prevent it from entering the canal system and the organism be partisan that the channel system on the input side with a Ste rilfilter is provided. In the case of a detachable recording device It is advisable to use the sterile filter in the receiving device order.

For particularly targeted spatial application of active substances, For example, growth factors in particularly atrophy deten districts, it is advantageous that the outlet openings under are distributed in different densities on the surface of the implant and / or that they are of different sizes.

It can be particularly advantageous that the surface of the implan tates is covered with a porous material. By this measure a fine distribution of the active substances can be achieved. Except that has a porous layer when using growth factor Ren advantage that the tissue grow deep into the layer and can establish a firm connection.  

A preferred further development is that the implant essentially entirely of a porous material is, and that the channel system in a predetermined Ab stood by the implant surface ends.

It appears appropriate that hydroxyapatite as the porous material or ceramic is used.

In the embodiment of the invention described above, it is expedient that the receiving device is detachable and made of metal is trained.

In addition, it can also prove advantageous that the outlet openings of the duct system with sieves or filters are provided to prevent the penetration of corpuscular components to prevent the blood. Such bodies that clot processes arise, otherwise a ver cause the duct system to become blocked.

The invention is preferably further developed in that the walls of the canal system with anticoagulant substances are covered. Such substances are known in the art and therefore need no further explanation here.

In the following the invention based on several execution examples further described.

Fig. 1 shows purely schematically a longitudinal section through a first implant

Fig. 2 shows schematically a longitudinal section through a second implant and

Fig. 3 shows schematically a longitudinal section through a third implant.

As illustrated in FIG. 1, a first implant 1 , which in the example shown here is designed as a thigh prosthesis, is provided with an internal channel system 2 . This leads from a receiving device 3 to a plurality of outlet openings 4 on the surface of the first implant 1 . To simplify the illustration, the outlet openings 4 in FIG. 1 are evenly distributed, although under certain circumstances it may be expedient to provide a different distribution. For the same reason, the channel system 2 is limited to the reproduction of a single central channel 5 and branches 6 extending therefrom. In the example shown, the first implant did 1 and the receiving device 3 are integrally formed. In such an embodiment, the first implant 1 and the receiving device 3 are made of metal, for example. The channel system 2 is drilled into the implant.

As an alternative, it is also possible to use the channel system Arrange cables on the surface of the implant (not shown). This design of the channel system is special useful for a flat implant.

The left side of the first implant 1 is coated with a porous material 18 exclusively for better illustration of the invention. The outlet openings 4 thus open into the po rous material 18th As the right side of the first implant 1 illustrates, the outlet openings 4 can also open directly on the surface of the first implant 1 .

The receiving device 3 is prominently formed on the first implant 1 so that it can be distinguished from the rest of the implant by X-ray and uniquely located. The inlet opening 7 of the receiving device is provided with a sealing membrane 8 , which can be made of silicone rubber, for example. A sterile filter 9 for filtering microorganisms lies behind it at a safety distance. As will be described below, the sealing membrane 8 is pierced by an injection cannula 10 during a transcutaneous injection, the safety distance preventing damage to the sterile filter 9 .

The inlet opening 7 of the receiving device 3 is provided in the example shown with an internal thread 11 , which has the task of enabling a detachable connection to a pressure pipe 13 with a corresponding external thread 12 . The pressure tube 13 , which is only required in the case of an injection under pressure, and which receives the injection cannula 10 , is also introduced transcutaneously.

The receiving device 3 is designed as a radiographically visible nozzle.

For further understanding, the application of the invention is described by way of example below. The implant 1 is inserted in the usual way during an operation in the organism (not shown). Due to the channel system 2 and the practically repeatable access via the receiving device 3 , a wide range of options for targeted spatial, timely and repeatable supply of the adjacent tissue with active substances are created. A liquid carrier medium with the active substance in question is injected transcutaneously with the help of the injection cannula 10 , alternatively using the detachable pressure tube 13 . After each injection, the Injektionskanü le 10 and the pressure tube are removed from the organism so that the subject does not experience any disability.

The insertion of the injection cannula 10 and optionally the pressure tube 13 into the receiving device 3 is carried out under X-ray monitoring, which is facilitated by the raised, characteristic shape of the receiving device 3 . In the case of a flush design of the receiving device 3 , this can also be carried out by other radiologically identifiable markings, such as humps or the like (not shown).

In Fig. 2 a variant of the implant 1 'is illustrated purely schematically. Here are two separate and independent channel systems 2 , 2 ', each with its own receiving device 3 and 3 '. The outlet openings 4 , 4 'of the two channel systems 2 , 2 ' are arranged in such a way that certain adjacent tissue regions (not shown) can be supplied with the desired active substances in a targeted and independent manner. In FIG. 2, the left channel system 2 is assigned to the left implant side and the right channel system 2 'to the right implant side for the sake of a clear representation.

In addition, Fig. 2 illustrates in an area 14 of the implant 1 'by way of example that the density of the outlet openings 4 ' on the surface of the implant 1 'can be of different sizes in order to be able to supply different amounts of the active substances to predetermined regions. This purpose could also be achieved by the fact that the outlet openings 4 , 4 'are under different sizes (not shown).

In Fig. 3 a third example is shown of an implant. It consists of a porous material, such as hydroxyl apatite. The result of this is that the active substances injected into the channel system 2 '' can pass through the walls of the channel system 2 '' into the implant, which is indicated purely schematically by star-shaped arrows 15 . In this way, the substances are evenly and finely distributed and can exert their effect optimally in the implant and on the surface of the implant. It may therefore be superfluous that the channel system 2 '' is provided with openings emerging directly on the implant surface, as shown schematically in Fig. 1 on the right side of the implant. As FIG. 3 shows, it is sufficient at such a material rather, that the channel system at a predetermined distance below the surface of the implant 1 '' ends.

Further shown in Fig. 3 schematically shows that the recording device 3 '' is detachably connected to the implant 1 '', respectively. For this purpose, the implant 1 '' at the entry opening 7 of the channel system 4 '' is provided with an internal thread 16 . The formed as a separate part receiving device 3 '' be sits a corresponding external thread 17 and can therefore be screwed into and out of the internal thread 16 . The intake device 3 '', which is otherwise provided with a sealing membrane 8 and a sterile filter 9 , can be made of a different material than the implant 1 ''. Metal is preferably used.

In accordance with the in Figs. 1 and 2, the "recording device 3" is input side with an internal thread 11 for acceptance on a pressure pipe provided.

The details described in connection with the figures The invention can of course be combined with one another will.

Claims (19)

1. Heterologous implant, for example an endoprosthesis, characterized in that the implant ( 1 ) is provided with at least one of each an associated receiving device ( 3 ) outgoing channel system ( 2 ) with outlet openings ( 4 ) distributed over the implant surface. 2. Implant according to claim 1, characterized in that a plurality of receiving devices ( 3 , 3 '') and associated channel systems ( 2 , 2 '') are present, and that the respectively associated outlet openings ( 4 , 4 ') in different surface areas of the Implants ( 1 ') are net angeord. 3. Implant according to claim 1 or 2, characterized in that the receiving device ( 3 ) is marked by at least one raised approach. 4. Implant according to claim 3, characterized in that the receiving device ( 3 ) is designed as a nozzle, the outline of which clearly allows X-ray localization. 5. Implant according to one of the preceding claims, characterized in that the receiving device ( 3 , 3 ') is detachably connected to the rest of the implant ( 1 ''). 6. Implant according to claim 5, characterized in that the implant ( 1 , 3 ') at the entrance to the channel system ( 4 '') with an internal thread ( 16 ) and the receiving device ( 3 ') with a corresponding external thread ( 17 ) for manufacturing a detachable screw connection is provided. 7. Implant according to one of the preceding claims, characterized in that the channel system ( 4 ) is provided on the input side with a sterile filter ( 9 ). 8. Implant according to claim 7, characterized in that the receiving device ( 3 ) with a cannula ( 10 ) penetrable sealing membrane ( 8 ) is closed. 9. Implant according to one of claims 7 or 8, characterized in that in the case of a detachable receiving device ( 3 , 3 '') the sealing membrane ( 8 ) and / or the sterile filter ( 9 ) in the receiving device ( 3 , 3 ') are. 10. Implant according to one of the preceding claims, characterized in that the receiving device ( 3 ) is provided on the input side with a sealing device for tight but detachable receiving a pressure tube ( 13 ) for a pressure injection. 11. Implant according to claim 10, characterized in that the sealing device consists of an internal thread ( 11 ) for receiving a corresponding external thread ( 12 ) on the pressure tube ( 13 ). 12. Implant according to one of the preceding claims, characterized in that the outlet openings ( 4 ') are distributed with different densities on the surface of the implant ( 1 ') and / or that they are of different sizes. 13. Implant according to one of the preceding claims, characterized, that it is at least partially made with a porous material is covered. 14. Implant according to one of the preceding claims, characterized in that it is made essentially entirely of a porous material and that the channel system ( 2 '') ends at a predetermined distance from the implant surface. 15. The implant according to claim 13 or 14, characterized, that ver as a porous material hydroxyapatite or ceramic is applied. 16. Implant according to claim 14 or 15, characterized in that the receiving device ( 3 '') is detachable and made of metal. 17. Implant according to one of the preceding claims, characterized in that the outlet openings ( 4 ) of the channel system ( 2 ) are provided with sieves or filters to prevent the penetration of corpuscular components of the blood. 18. Implant according to one of the preceding claims, characterized in that the walls of the channel system ( 2 ) are covered with anticoagulant substances. 19. Implant according to one of the preceding claims, characterized, that the channel system consists of lines that on the Surface are arranged.