DE2910627A1 - Implant which can be used as replacement for spongy bones - is built up from tolerated fibres which are implanted in bone cut=out - Google Patents

Abstract

A network which is stable in structure, and space-filling is constructed from threads or fibres which will not be rejected by the body, and can be implanted as a replacement for spongy bones. The threads or fibres may be of metals, metal alloys, ceramics, carbon and/or synthetics. At their crossing points the threads are joined by welds, etc. A shaped object may be produced from the network by pressing or embossing and immediately after cutting or dividing, forms the implant. The network may be shaped into a wedge, square, disc, etc. or a core with an envelope. The process develops implantation techniques so that after a short time the defective bone structure can stand the stresses encountered during normal use.

Description

Implant as a replacement for cancellous build-up

Bone The invention relates to an implant as a replacement for cancellous bones of the human skeleton. Such bones are z. B. the carpal and tarsal bones, the sections adjacent to the growth joining the long bones, vertebrae, pelvis, shoulder blades and large parts of the skull and the rib cage.

In the case of bone defects, fractures, compression fractures or required stiffening in bone joints, where previously cancellous bone had to be replaced was, so far this has been done by grafting (transplantation) of bones, whereby but the load-bearing capacity of the transplanted bone is not expected for a long time can be, because the removed bone is lost during the transplant process its bone cells as a result of separation from the bloodstream, and only the mineral ones the bony component remains at the place of implantation as an endogenous framework, which, however, is not sustainable and only over time due to the sprouting of connective tissue leads to new bone formation. This process, namely the incorporation of a bone graft is needed in its bony bed - until it is reached of a fully stable bone a long time, about 1 year.

The object of the invention is to provide implants for spongy structures Bones to be replaced or defective bone parts of the human skeleton to be trained in such a way that the skeletal part can be fully loaded again after a short time or is functional.

This object is achieved according to the invention by an implant, which is made up of body-compatible threads or fibers, dimensionally stable network characterizes, which is preferably continuously open-cell or has an open-pore structure.

If after this solution a cancellous bone defect with a body from the dimensionally stable network, - which is made of body-compatible fibers or Threads, in particular made of metals or metal alloys, so is immediately ensures primary stability and prevents connective tissue from sprouting in the network of the implant with subsequent remodeling in bone.

This cancellous implant remains permanently in its bone bed and in time it will grow with bones.

In addition to threads or fibers made of metals or metal alloys, in given cases also those made of ceramic material, carbon and / or Plastics come into use.

In order to stabilize the shape of the network body according to the invention or to stiffen the threads or fibers at the crossing points, for example Welding or chemically connected. The implant from the network can be brought into the desired and required shape by embossing or pressing or by cutting or dividing from a larger network body he follows.

According to the invention, it is also possible, in addition to the cancellous, off the existing implant network the growth of the implant through cancellous Promote bone next to the network implant during primary implantation being transplanted, taking the mechanical stress from the implanted network can be taken over immediately.

The invention is illustrated below with reference to the drawing examples discussed new network implant.

The implant as a replacement for cancellous bones consists of fibers, Threads or thin wires that are woven into a network or filmed in a film and made of biocompatible metal (titanium), metal alloys, ceramic material, carbon and i or plastic.

The crosslinked or matted threads or fibers are made by embossing or Pressing brought into the stable shape required for the respective bone defect or networked or filmed to form a larger body in a dimensionally stable manner, whereby from this Body can be cut out the required shape. The threads or fibers at the crossing points by supplying heat (welding) or chemically be connected in order to stiffen the network in a dimensionally stable manner.

For example, according to Figures 1 and 2, there is a compression fracture on the tibial head or on the heel bone (left part of FIGS. 1 and 2), it becomes erect an incision is made of the collapsed cancellous bone, and the bone parts are spread apart and then a corresponding one from the network Cancellous implant, e.g. inserted in the form of a wedge 1, with the wedge so can be introduced that he is firmly jammed in his camp, which the principle the rest position is achieved by distraction, so that under certain circumstances plaster casts or other support and holding measures can be saved. In the same way can in the case of a heel bone that has collapsed due to compression, proceed as shown in FIG will.

According to FIG. 3, there is a vertebral bone defect that has collapsed due to compression in a manner similar to that shown in FIGS. 1 and 2 to be surgically corrected, by placing a cancellous implant 2, e.g. in the form of a cuboid, in the apart to spread Vertebral bones inserted under firm restraints will.

When establishing firm connections between two cancellous bones are, according to Figure 4, the bone surfaces are prepared as it is e.g. '. at joint stiffening is required. It then becomes cancellous in the defect Implant 3 e.g.

used in the form of a cuboid, possibly together with to cancellous bone to be transplanted in order to accelerate the growth of the cancellous bone Promote implant with bone.

The rigid cancellous implant 3 is used to stiffen the joint better and safer because of the greater primary stability and dimensional stability than before and a faster functional stress can be expected.

In the case of an ankle stiffening according to FIG Figure 4, proceed in such a way that joint surfaces are to be prepared accordingly, e.g. to be resected, whereupon disc-shaped cancellous implants 4 possibly also be used together with cancellous bone, so that then by sprouting from connective tissue in the cancellous implant the formation of cancellous bone takes place and thus the ankle bones grow together stiffened.

According to Figure 6 it is also possible, after resection of a false joint, e.g. a thigh, the defect by inserting a cancellous implant 5 between the two leg parts to replace, then the the two parts of the femur can be splinted together.

According to a further case, it is also possible according to FIGS. 7 and 8, with a cancellous implant 6 a rigid core, e.g. the shaft of a ball joint prosthesis (Fig, 7) or the shafts of a knee joint endoprosthesis (Fig. 8), to envelop thereby ensuring a large-area connection to the bearing bone more favorable conditions for the cementless implantation of joint prostheses created in the area of the shafts of long bones.

According to a further example of FIG. 9, a tumor can 7 destroyed bone part by an implant 8 from a dimensionally stable network of the invention are replaced.

In all applications that are not covered by the drawing examples are limited in which the cancellous implant according to the invention can be used comes, the implant remains in place of the defect to be repaired and immediately becomes functional due to its primary stability and dimensional stability Stresses too. The cancellous implant promotes the ingrowth of connective tissue and with it the rapid ~ formation of cancellous bone.

Claims (6)

Claims 1.) Implant as a replacement for cancellous bone, characterized by means of a dimensionally stable structure made of body-compatible threads or fibers Network. 2. Implant according to claim 1, characterized in that the threads or fibers optionally made of metal, metal alloys, ceramics, carbon and / or plastics exist. 3. Implant according to claim 1 or 2, characterized in that the Network is stiffened in itself by connecting the threads at the crossing points. 4. Implant according to one of claims 1 to 3, characterized in that that the network is housed in an open socket. 5. Implant according to one of claims 1 to 4, characterized by a molded body produced from the network by embossing or pressing, which directly or the implant forms after trimming or fragmentation. 6. Implant according to one of claims 1 to 5, characterized in that that the network in the shape of a wedge, cuboid, a disk or a one The core surrounding the shell is brought.