DE2444668A1 - JOINT PROSTHESIS - Google Patents

Description

Dipl.-Ing. H. MITSCHERLICH Ρ —8 PIGS 22

Dtpf.-Ing. K. GUNSCHMANN Steinedo-Strasse 10

IY .. »A # liÄDBCD 'S" (089) '29 66 84

Dr. r * r. not. W. KORBER Dipl.-tng. J. SCHMIDT-EVERS

Patent Attorneys ^{1 a} September 1974

CUTTER LABORATORIES INC.,
Fourth, and Parker Streets
Berkeley, California WIO / V.St.A.

Patent application

Joint prosthesis

The joint prosthesis according to the invention serves as a replacement of a skeletal joint and consists of a single piece of elastomer, which is a central joint part with a shaft arranged at each end, which are inclined towards one another and at an angle between them lock in. Each shaft has a base area that can be inserted into a medullary canal of a bone of the joint is trained. The hinge part has a hinge band between the thicker end parts of the two shafts and allows a pivoting movement in only one plane, in which the enclosed by the shafts Angle lies. The joint ligament gives the prosthesis a mutual inclination when it is not put on of the two shafts, in which there are no tensile or compressive stresses in the prosthesis. The elastomer is with a also provided with internal reinforcement or reinforcement made of strands or cords through the hinge that consist of fibrous material and arranged plane-parallel or in only one plane within the hinge

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are. At least one of the shafts can be stiffened by a sleeve, and an open-pored, three-dimensional, reticulated one The outer layer of the shafts enables cell tissue to grow into this outer layer, creating a firm Connection or anchoring of the joint part kept free of such an ingrown tissue is guaranteed.

Accordingly, the invention relates to a joint prosthesis for the replacement of a skeletal joint with two each stems which can be inserted into the medullary canal of a bone of the joint, each of which is provided with a reinforcement or reinforcement insert and a cushion cover made of an elastomer and with an outer, an open-pored, three-dimensional reticulated Structure-having layer is provided, which is suitable for cell tissue ingrowth.

Mr the replacement of joints used to connect bones, Like elbow joints, knee joints, and wrists, prostheses are known to be either rigid Metal or plastic, or of softer materials such as elastomer, are made, as described in the US patents 3,462,765 and 3,593 34-2. Those made of metal or hard plastic Existing prostheses of this type are unsuitable for longer periods of use, as those in the medullary canals of the Stems introduced into bones often become loose. This is probably due to the large local pressure loads, to which the bones are exposed through the hard surface of the prosthesis material and through the small Blood bags and damage to neighboring tissues are caused, causing resorption of the bone and a Death of the affected area. This effect is often only noticed when the patient has partially recovered and tries to move the replaced joint in the usual, powerful way.

With the prostheses made of softer material, such local pressure loads are avoided, but

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there are other difficulties which can be attributed in particular to the fact that special additional bending points occur at the connection points between the shafts and the central joint part and thereby displacements of the joint or the joint action. It has been found that the useful life of a joint prosthesis made of a softer elastic material can be extended if the central area of the joint part is made thinner and reinforced by two layers of reticulated tissue, as is the case, for. B. is known from US Pat. No. 3,593 34-2 for an ankle or finger prosthesis. However, this mesh or braid reinforcement, which is also present in the shafts of the prosthesis, has not proven to be sufficient to reduce or avoid the additional bending points or secondary articulation points at the base of the shafts in those cases in which the surgeon uses the shafts has not fully inserted into the medullary canal of the bone or has not temporarily anchored the shafts to the bone with sutures! Has. Clinical testing of elbow prostheses of the same design and structure has shown that a braid reinforcement through the thin central area of the joint does not significantly extend the service life of the prosthesis and that cracks and fractures occur in the thin central area. These are probably due to the fact that the thin central area is exposed to greater bending forces because the prosthesis is implanted in the elbow joint on a part of the body that is subjected to greater loads than the knuckles of the hand and which is also more angled than the latter. The creation of second joint points at the connection point (s ₎ ZWiS 1 ChOn the shafts and the joint part therefore represents a serious problem.

The invention is based on the object of solving this problem.

Here , the invention proposes a strong, with reinforcement or. Prosthesis with reinforcement inserts to replace

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skeletal joints, such as elbow, pinger, toe, knee and shoulder joints, in which the reinforcement or reinforcement inserts are enclosed by a padding structure layer and the shafts with a fibrous outer layer are provided, which supports the ingrowth of the patient's cell tissue and a firm connection of the prosthesis with the bones of a human or other skeleton. In this way, the prosthesis after the Invention components made of hard plastic or metal that could come into contact with the outer surface of the bones, as well as avoiding the resulting difficulties. The prosthesis can be used with a minimum of risk of infection attached and used with a long service life. It is also made possible that the components of the prosthesis can be so effectively and firmly connected that a reliable, load-bearing and high-strength transmission the load from the reinforcement or reinforcement insert via the elastomer compound to the patient's bone is guaranteed. The reinforcement or reinforcement insert in and on the shafts is particularly advantageous because it enables them the prosthesis provides a high level of strength against undesired bending at other points than on the joint part will.

The joint prosthesis according to the invention can be used both in humans and in animals, to a damaged or sick person Replace articulated joint. It represents a uniform device lying essentially in one plane with a central joint part and shafts extending from this in opposite directions, in which the The joint part is thicker at the connection points with the shafts and thinner in its central area and thinner in this area Area forms a hinge that can be bent easily and without the risk of cracking or other damage can be. The prosthesis is made of body-compatible elastomer and an inner one made of fibers, loads or cords Reinforcement or reinforcement insert composed of the-

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art is arranged and dimensioned so that the flexural strength of the shafts in every direction and in particular also at the connection points the shaft with the joint part is significantly increased. The reinforcement or reinforcement insert also works through the middle hinge band of the hinge part, being arranged so that on the one hand it supports the bending processes in the hinge ligament is not impaired, but on the other hand the hinge ligament is reinforced in such a way that cracks or fractures of the Joint ligament, also on the side edges of the same are avoided. This increases the useful life of the planted The prosthesis is considerably longer.

According to the invention, these improvements are achieved by that the reinforcement or reinforcement insert of a plurality of in the longitudinal direction substantially through the entire Prosthesis consists of continuous cords that can be bundled or interwoven in the area of the shafts and occupy a substantial part of the mass of the shafts and which also occupy the central joint band of the joint part form, in which they are arranged essentially parallel to each other and in only one plane. Such cords and theirs Arrangement are reinforcements or reinforcements from several layers of braid superior because such braid layers the connection points between the joint part and the shafts hardly increase the flexural strength. There are also those Braids at these points are less break-proof because only half of the braided cords run lengthways through the hinge passes through. Finally, in the case of the prosthesis according to the invention, the shafts have an outer layer of one The open-pored tissue that promotes ingrowth of cell tissue is provided between this and when the prosthesis is attached forms a tight, firm and indissoluble connection with the body tissue.

Another important feature of the invention is that the two shafts are formed in a common plane one of them included angles are arranged,

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which is between 90 ° and 160 ° when the prosthesis is not in place and at the tip of which the ligament is located. Here are the shafts in relation to the joint ligament of the joint part each according to which joint is to be replaced by the prosthesis, angled so that the one enclosed by them Angle corresponds to the angle at which there is no bending stress on the hinge, which makes the possibility excessive considerable stresses on the joint ligament when the prosthesis is attached due to stretching and bending movements is decreased. In addition, the angled arrangement of the shafts according to the invention ensures that in the case of the joint prosthesis, after it has been applied, there is little or no bending stress in the body joint concerned assumes its normal position of rest, since the angle at which the prosthesis is made essentially corresponds to the angle, which is present in the body joint when it is in the rest position. This is in contrast to a Joint prosthesis, in which the shafts lie in a straight line when the prosthesis is not in use, prevents the prosthesis is subjected to permanent or excessively high bending loads after it has been planted.

The prosthesis according to the invention is preferably provided with external fastening or anchoring cords, which are located in the base area of one or both of the shafts are arranged on the prosthesis. With the help of such cords is made possible one or both shafts immediately and in the meantime until cell tissue has grown into the bone anchor and secure against rotating or sliding movements. According to a further feature of the Invention are formed in that some cords of the reinforcement or reinforcement insert after their passage through the joint part in the base area of the shaft or shafts are guided out of the prosthesis. They then correspond to the natural ones lateral tendon ligaments, which are generally cut away when attaching the prosthesis. The fastening or anchoring cords can be used as components of the prosthesis

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are firmly attached during their manufacture, while loose cords light up when the surgeon attaches the prosthesis correctly, can be attached and are subject to the risk of being torn by the elastomer.

If necessary, the reinforcement or reinforcement insert additionally contain a rigid core member z. B. consists of hard plastic or metal and is about the largest Part of a shaft extends into the adjacent end of the joint part, but does not extend into the hinge. Such a rigid core member is particularly important when a deeper resection of a joint, e.g. B. an elbow joint, requires a prosthesis that must be rigid in the area where it replaces the removed bone The term "rigid" is to be understood here in the true sense of the word. E.g. an elbow bone is rigid in this sense, while the stems described in U.S. Patent 3,593,334-2 are not rigid. Also z. B. a wooden strip of 2 by 4 cm rigid in this sense, while a carpet is not is rigid.

In addition to the inner reinforcement or reinforcement insert in the base area of one or both shafts, the prosthesis according to the invention can also be designed in a different way in such a way that undesired second bending or second articulation points are avoided. For this purpose, the prosthesis can be provided with a stabilizing sleeve made of non-rigid, but moderately flexible material, which is fastened in the base area of at least one of the shafts and surrounds the shaft towards the outer end. When the stem is inserted into the medullary canal of a bone j, so that the cuff defines with its \ inner surface sealingly to the outer surface of the bone: on. The inner surface of the cuff consists of an open-pored material so that bone tissue can grow into the inner surface of the cuff and the bone is thereby firmly connected to the cuff.

ι '

: Below is the invention on the basis of the drawing as an example

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wisely described. In the drawing show:

1 shows an elbow prosthesis designed according to the invention with a stabilizing cuff on one of the shafts in front view with partially omitted Outer layer,

FIG. 2 shows a side view of FIG. 1,

3 shows a further embodiment of one according to the invention Elbow prosthesis in front view with a cuff partially shown without an outer layer,

FIG. 4 is a side view of FIG.

5 shows the front view of the elbow prosthesis according to FIG. Λ , in which the outer ingrowth layer and the cuff have been omitted,

6 is a perspective view of successive layers of part of the elbow prosthesis of FIG Fig. 1, in particular the longitudinal reinforcement strands this embodiment,

7 shows an ankle or ankle joint designed according to the invention. Finger joint prosthesis in perspective view,

8 shows the ankle prosthesis according to FIG. 7 in a somewhat enlarged manner Side view, and

9 shows the ankle prosthesis according to FIGS. 7 and 8 in plan view with omitted outer ingrowth layer.

The elbow prosthesis 90 shown in FIGS. 1 and 2 is with an upper shaft 91 is provided, which extends according to its base region widened towards a flange 92 and there connected to the upper end 93 of the joint part. Farther the prosthesis has a lower shaft 94 that follows its base area also widened to a flange 95 and there with the lower end 96 of the joint part connected is. The two shafts 91 and 94 close with the Hinge band 98 an angle on the order of 90 ° to 160 ° and are each equipped with a reinforcement or reinforcement insert made of flexible material consisting of fibers, in particular polymeric material such as Dacron. It

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Fibers made of metal, fiberglass or carbon can be arranged. The reinforcement insert preferably consists of Lacing 97 »especially braided cords that are likewise extend through the hinge part and pass longitudinally through the hinge band 98. The reinforcement cords are impregnated with elastomer. Furthermore, there is padding by an elastomer insert 99, especially in the large ones Areas of the upper and lower end portions 93 and 96 of the joint prosthesis educated. The shafts 91 and 94- are with a Outer cover layer 100 is provided from a tissue suitable for the ingrowth of cell tissue, which generally consists of a Braid or made of velvet, e.g. B. Dacron or Teflon braid or velvet, or if the prosthesis is made of an elastic type of Polyurethane is made, can also consist of polyurethane, which is three-dimensional reticulated.

The upper shaft 91 is not single in the base area outer stabilizing supports, but with a reinforcement Stabilization cuff 101 is provided, which consists of a relatively strong, but flexible material, the inside with an ingrown fabric 102 and on the outside with a Layer 103 is clad from elastic polymer. The cuff 101 penetrates the base portion of the upper shaft 91 Seams 104 and, if necessary, additionally fastened by adhesive. As shown in Fig. 1, the cuff 101 is through a single A piece of fabric is formed which is wrapped around the base region of the shaft 91 in such a way that its two front ends 105 and 106 collide. The cuff, which also consists of two or more pieces can be put together, serves to tightly wrap the outer bone surface of the severed shoulder or shoulder. Humerus after the shaft has been inserted into the medullary canal of the bone. This is how the denture becomes solidified by the bone ingrowth into the pores of the inner surface 102 and prevents a second hinge formation or a displacement of the joint occurs in the base area of the shaft. In several places on the upper edge fastening cords 107 can be attached to the cuff 101

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to temporarily attach the cuff to the bone and rotational or longitudinal movements of the shaft 91 are avoided until cell tissue has grown into the inner surface of the cuff. Fastening or anchoring cords 108 can also be attached to the widened flange 95 in the base region of the shaft 94, around the shaft as well to stabilize temporarily until such a tissue ingrowth has taken place that a permanent solid connection with the shaft 94 consists.

The one in Pig. 3 and 4 shown embodiment of an elbow prosthesis 120 is formed in essentially the same way as prosthesis 90, but in addition to that outer reinforcing and stabilizing cuff 101 nor an inner rigid reinforcing member 121 made of metal or Plastic for the upper shaft 91 on. This reinforcing Core member 121 can be designed in such a way that it increases the strength in particular in the area of the upper end 93 of the joint part and increased in the base region of the upper shaft 91, so that a second joint formation or effect is prevented there will. For example, the core member 121 can be wider or thicker and in the base region of the shaft 91 and in the upper end 93 of the Joint part take up more space. The elbow prosthesis 120 is particularly suitable for replacing an elbow joint in FIG Suitable cases in which a higher resection of the humerus necessary is. For this purpose, the upper end 93 of the prosthesis 120 can be correspondingly longer and the flange 92 in the base area of the shaft 91 can be made smaller in order to adapt to the bone area which is smaller in the case of a higher resection.

Both elbow prostheses 90 and 120 can around the base area of the lower shaft 94 around a second sleeve be arranged. In addition, 101 fastening cords can be attached to the cuff 107 and in the base area of the shaft 94 fastening threads 108 be arranged.

The ankle or finger joint prosthesis shown in FIGS

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140 has a central hinge part 141 with thick hinge halves 142 and 143, with each of which a shaft 144 and a shaft 145 are connected. The shafts are on their respective base 146 and 147 have a larger cross-section and then taper towards the a smaller cross-section having ends 148 and 149 out. The joint halves 142 extend towards the center over the base region of the shafts 144, 145 and form abutment cushions against which support the severed bone ends of a finger joint.

The joint part 141 forms a generally rectangular block which is located in the middle between the two joint halves 142, 143 is provided with a perpendicular, transverse to the shafts slot 152, which extends from top to bottom into the lower end of the block is enough. Here the vertical slot 152 goes into a narrow horizontal slot 153 about, which also runs transversely to the shafts and together with the slot 152 is an inverted T-shaped in cross section Forms slot. A narrow strip of material continuous in the transverse direction then remains in the lower end area of the block 154, of the two joint halves 142 and 143 of the joint part 141 connects to one another as a hinge band. This ribbon-like design of the articulated connection has the advantage that when the prosthesis is bent, the Bending stresses are distributed over a wide range and therefore for the elastic material in the hinge strap 154 are less harmful. This is not the case with joint prostheses that do not have a particular width in their bending area Case, because then the tensions are concentrated in a very narrow area and this results in rapid destruction of the articulated connection entry. The lower surface 164 of the joint part or block 141 is curved concavely in cross section, see above that the joint block is thinner in the area of its transverse center plane and on its two outer transverse edges, close to the shafts 144 and 145 is thicker. This increases the flexibility of the erothesis is improved and the amount of elastic material that migrates during bending is reduced.

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Inside, the prosthesis 140 contains a plurality of longitudinally arranged cords 158, preferably Dacron cords or cords. -threads that the inner reinforcement or reinforcement insert to extend the durability of the hinge tape 154- against Form bending and to stiffen the connection areas of the shafts against undesired joint action in these areas. This reinforcement insert also stiffens the shafts themselves, so that they can more easily be inserted into the medullary canals of the bones can be introduced. The cords 158 extend over the entire prosthesis and in the region of the joint part 141 also over its entire width, whereby they are essentially parallel run towards each other.

Special fastening or anchoring cords 159 can be arranged in the base region 146, 147 of the shafts 144, 145. These can, however, preferably also by means of external ones Cords 158 are formed of the reinforcement insert, which are through the joint part 141 go through, but then not guided into the shafts, but at the connection points are led out of the prosthesis between the shafts 144, 145 and the joint part 141. The suture threads 159 correspond to especially in the preferred embodiment, the natural ones Lateral tendons or ligaments when they are pulled into holes in the ends of the severed bones. They give the prosthesis 140 a firm hold immediately after it has been attached so that it does not rotate or come out of the medullary canals can slide out.

The reinforcement cords 158 are when transitioning into the Shafts 144, 145 are preferably bundled and twisted or braided into one another. In the area of the joint part 141 they can through a layer of braid 160, e.g. B. a Dracon braid, woven or on the braid layer 160 with Eohsilikon rubber or other adhesive. In this way, the arrangement of the cords 158 in the manufacture ment of the prosthesis and its layering facilitated in a manufacturing form in which the elastomer 161, z. B. silicone;

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Rubber, with the reinforcement cords embedded will give. However, the arrangement of the braid 160 is also not essential for the reinforcement in the area of the joint part 14-1 necessary.

After the prosthesis as a whole by pouring the elastomer 161 into a manufacturing mold and embedding the reinforcing cords 158 is made, the shafts 144, 14-5 with a coating 162 made of an open-pored material suitable for cell tissue ingrowth, e.g. B. Dacron braid or -all, provided. If a braid 160 is used, it is preferably arranged in at least two layers, the held together by the strings 158 penetrating seams will.

As Fig. 8 shows, the shafts 144, 14-5 are of the ankle prosthesis 140 arranged on the joint part 14-1 in such a way that they include an obtuse angle between them, which however is not as stressed as with the elbow prosthesis and is around 130 ° to 160 ° when the prosthesis is not attached. According to FIG. 8, the angle is 160 °, while such an angle is preferably about 90 ° to 155 ° in the case of the elbow prosthesis Is 100 ° to 120 ° and especially 105 °. This preferred angle of 105 ° with which the elbow prosthesis is made allows the joint to be bent no more than about 60 ° in any direction, even if the Forearm is fully extended. This avoids an excessively strong bending and an extended service life for the most sensitive part of the joint prosthesis, namely the ligament, reached. Another essential consideration for the formation of a joint prosthesis with such a joint obtuse manufacturing angle between the shafts is that after attaching the prosthesis, during which the body assumes its normal rest position, there is little or essentially no bending of the articular ligament of the prosthesis.

The joint prosthesis according to the invention is manufactured

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for example in such a way that a large number of Dacron strands or cords 97 »preferably braided, impregnated with raw rubber (" Silastic ") and partially with the same Raw rubber-filled form according to FIG. 6 arranged in this way that they go through from shaft tip to shaft tip. The braided or non-braided cords are in the shaft areas braided or otherwise bundled or simply arranged next to one another. If there is a If a metal insert is to be arranged as reinforcement, it is inserted between the layers of cord «, in the joint area the cords are loosely connected to one another by seams 109 and spread over almost the entire width of the joint part, so that they lie in a single plane. Then raw rubber (Silastic) is introduced into the mold halves, the mold closed and their contents vulcanized. The shafts can then be provided with a coating layer 110 made of silicone rubber reinforced by a Dacron mesh. Possibly The entire prosthesis can also have a covering layer 111 made of silicone rubber reinforced by a Dacron mesh be provided. A material suitable for cell tissue ingrowth, preferably Dacron braid, is placed on the shafts or velvet applied. If a braid is used, two to four braid layers are preferably arranged, which are attached to the reinforced shafts by seams. When using velvet, a layer of velvet is sewn on. The velvet is preferably backed with a layer of raw rubber (Silastic) so that the velvet layer is vulcanized on will. It can also be attached x ^ earthed by sewing.

In the case of the prostheses to be provided with a cuff! the cuff is attached to the IPl by means of sutures. The cuff has an outer layer made of Silastic and an inner layer made of ingrowth material such as velvet. The finished prosthesis can then be dried for a while. In addition, in the base area of the lower shaft and in places ^; pull cords are placed near the upper edge of the cuff and drawn into the ulna and humerus.

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Surgical application of the joint prosthesis according to the invention takes place in the usual way. Below are the procedures required for this using the example of the elbow prosthesis and the ankle prosthesis.

1. To attach the elbow prosthesis, it is first cleaned and made sterile. The arm of the under general anesthesia lying patient is made bloodless, and the flow of blood is interrupted with a tourniquet to reach a relatively bloodless surgical field. Near A posterior skin incision is made in the elbow joint and large flaps of skin are taken care of develop. The nerves passing through the joint are also carefully isolated and protected.

2. The distal end of the humerus is exposed and cleansed of all soft tissue before it is placed horizontally in close proximity to the hook and the pit of the elbow is separated. Since full mobility is to be restored, care must be taken to ensure that the whole muscle structure is preserved. The origin of the Forearm muscles and the secondary ligaments must be detached from the distal end of the humerus.

3 · The radial head is cut out of the neck piece and the end of the elbow close to the body is cut away along a line starting from the tip of the elbow hook. Included the prominent surface of the joint is cut away in such a way that a solid angled bone collar is formed, which corresponds to the flange part 95 of FIGS.

4. From the exposed open ends of the ulna and humerus The medullary canals for receiving the shafts of the prosthesis are cleared out using burs and rasp. In addition, two grooves can be cut at the distal end of the humerus, which when using outer support elements correspond to these.

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5. After the shafts of the prosthesis are completely and tightly fitting have been inserted into the medullary canals, the elbow joint can be bent over its full range of motion, whereupon the prosthesis is temporarily attached by means of wires and / or sutures passing through its flange portion. The fastening cords 108 (Fig. 1 and 3) can also be used for this purpose. be used. Finally, bone meal is added until fibrous ingrowth has occurred on the shafts.

To use the prosthesis 90 or 120, the outer surface of the free end of the humerus scraped off so that a rough bleeding surface arises, whereupon the cuff 101 is placed around this rough bone surface with close contact will. Any overlapping parts of the end faces IO5 and 106 the cuff are cut away, whereupon these front ends are sewn. Any existing fastening or anchoring cords 107 are pulled through openings drilled in the bone to further secure the cuff.

6. When the wounds are closed as usual, the parts of the three-headed upper arm extensor muscle are reattached. After During surgery, the elbow is immobilized for four weeks before moving again.

7. Numerous clinical cases including those listed above Procedures applied resulted in a satisfactory, painless and relatively stable Restoration of normal function. In most cases, the elbow and the distal end of the humerus were missing as a result of an accident or previous surgical treatment. In other cases it was Injuries with wound fever and painful joint insertion as well as loss of movement as a result of finally occurring » Joint inflammation with wound fever.

For the surgical application of the ankle prosthesis according to the invention is

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a) again a clean, sterile prosthesis (prosthesis for a Intermediate finger joint or the joint between a last finger bone and the corresponding metacarpal bone) and a sterile operating field and general anesthesia are required for the patient. The arm is made anemic to be bloodless Surgical field and the blood supply is cut off by applying a tourniquet to the upper arm. For the Metacarpal joint prosthesis, a posterior incision is made that contains the extensor tendon and the connecting capsule exposed. The joint is exposed with great care in order to avoid tissue parts for later restoration to obtain.

b) The lateral tendon ligaments are detached from the metacarpal head so that the joint can be displaced. The metacarpal head is then cut out transversely, taking care that there is enough space to arrange the middle joint part of the prosthesis and for sufficient loosening of the tissue, so that a realignment without residual force at the joint or tissues.

c) Then the medullary canals close to and distant from the body are cleared for receiving the shafts of the prosthesis and the prosthesis applied on a trial basis. The finger or fingers are bent through their entire range of motion to show that a satisfactory function has been achieved.

About 2 mm behind the open end of each bone, two small holes are drilled through the dorsal surface, one in the central area and one in the side area, inserted into the cords 159 (cf. FIG. 9J) arranged accordingly on the prosthesis will.

d) The wound is cleaned of all particles and flushed with an antibiotic. The prosthesis is also cleaned and immersed in an antibiotic.

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e) The prosthesis is inserted into the prepared medullary canals by first placing needles on the bone anchoring cords 159 attached and then through the four drill holes be pulled through the two bones. The anchoring cords are so strong that they are natural resemble (and replace) lateral tendons and, by immediately anchoring the prosthesis shaft to the bones, one Ensure immediate strength and restoration of the joint effect. This has the advantage of to be able to move the joint at an early stage, but at the same time also, the healing through the immovable hold in the bones and through early solid ingrowth of cell tissue. For this anchoring, the two are close to the body Threads and the two threads distant from the body are tightened on the bone near or distant from the body and on one side of the respective bone anchored. The finger is then moved through its entire range of motion, at the same time the lateral strength is checked. Any setting corrections can be made.

f) The severed lateral tendons or secondary tendons can be arranged again for reattachment and, if necessary, close to the body are sutured to the bone anchoring cords in order to reattach them in the case of a "Dacron bridge" prosthesis to support.

g) The joint capsule is closed, carefully restoring gentle tissue alignment and placing the extensor tendon in place. Then the skin is closed. Finally, the hand is bandaged and placed in a mold or a rail in such a position that the finger or fingers to the articulated part is substantially the same angle as with non-scale prosthesis, ie an angle of about I5O ⁰ to 160 °, include. After the first week, careful movement of the joint is started under supervision. Unrestricted use of the hand should not be before four

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up to six weeks.

Suitable materials for the prosthesis according to the invention include rubber, rubber-like elastomer, elastomer, with in any case a material suitable for medical purposes is to be understood as it is commercially available e.g. B. under the brand name "Silastic" (Dow Corning Co.) is available.

Claims ;

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Claims (1)

Claims Joint prosthesis for the replacement of a skeletal gel with two shafts which can each be inserted into the medullary canal of a bone of the joint, each of which has one Reinforcement or reinforcement insert and a cushion cover made of an elastomer and with an outer, one open-pored, three-dimensional reticulated structure having layer is provided, which is responsible for the ingrowth is suitable for cell tissue, characterized in that the prosthesis has a common reinforcement for the two shafts or reinforcement insert of a plurality of lengthwise continuous through the shafts (91, 94; 144 ·, 145) has continuous cords (97 »158), the shafts with the formation of a hinge band that enables the shafts to pivot relative to one another (98, 154) connect with each other, arranged plane-parallel in the hinge and there with a cushion cover (99) are made of elastomer, which consists of one piece with the padding of the shafts. Prosthesis according to .Anspruch 1, characterized in that the Cushion cover (99) made of elastomer contains fibrous components and with the reinforcement or reinforcement insert is connected with at least partial wrapping of the same. Prosthesis according to Claim 1 or 2, characterized in that the two shafts (91, 94; 144, 145) are arranged in a common plane with the formation of an angle enclosed by them, which is between 90 and 160 I when the prosthesis is not attached
the hinge (98, 154) lies. Prosthesis is between 90 ° and 160 ° and at its tip 4. Prosthesis according to claim 5 for the formation of an elbow joint, characterized in that of the shafts 509813/0366 (91, 9 ² J-) included angles is about 100 ° to 120 °. 5. Prosthesis according to claim 3 for the formation of a finger joint characterized in that the shafts (144, 14-5) included angles is approximately 130 ° to 160 °. 6. Prosthesis according to one of the preceding claims, characterized in that the cords (97-158) of the reinforcement or reinforcement insert in the hinge (98, 154) in the Distance from each other and in the shafts (91, 94) merged or twisted together. 7. Prosthesis according to one of the preceding claims, characterized in that it is in at least one of the shafts (91 or 94) is additionally provided with a rigid reinforcement member (121). 8. Prosthesis according to one of claims 1 to 6, characterized in that that it has a rigid reinforcing member (121) for each of the shafts (91, 94), each ending before the hinge (98, 154). 9 · Prosthesis according to one of the preceding claims, characterized characterized in that some of the cords (97, 158) of the reinforcement or reinforcement insert from at least one of Shafts (91, 94) are led out and anchoring cords (107, 108) for fastening the prosthesis to the bone form. 10. Prosthesis according to one of the preceding claims, characterized in that it is provided with seams (104) for connection the ingrown layer having the reticulate structure (100) is provided with the elastomer. 11. Prosthesis according to one of the preceding claims, characterized in that the hinge (154) as a thin 50981 3/0366 middle band formed between two thick joint halves (142, 143) of a block-like joint part (141) and for distributing B-joint forces over a substantial portion of the ligament from one in the joint portion running transversely to the shafts (144, 145), vice versa T-shaped slot (153 »152) is superimposed, with the hinge on the opposite of this slot Side is curved concavely in cross section that its thinnest part is in the middle and its thickness according to the Increases towards shafts. 12. Prosthesis according to one of the preceding claims, characterized in that the reinforcement or reinforcement insert ' the cords (97 »158) in the region of the wrist band (98, 154) in only one plane and in each shaft (91, 94; 144, 145) as a generally cylindrical bundle. 13. Prosthesis according to claim 12, characterized in that the cords (97 »158) are connected to one another by seams. 14. Prosthesis according to one of the preceding claims, characterized in that the cords (97, 158) are braided. 15 · Prosthesis according to claim 8, in which the shafts are provided with widened end parts at their mutually facing ends, characterized in that the rigid reinforcement member also extends into the widened end part, not even into the hinge (98). 16. A prosthesis according to one of the preceding claims, characterized in · that it comprises at least one of the fixed a shaft in the base region and having a form suitable for the ingrowth of cellular tissue inside surface (102) provided with stabilizing collar (101), at least a portion of the shaft loosely surrounds its outer end and, when the prosthesis is put on, it encompasses the outer surface of the bone in which the shaft engages. 509813/0366 17 · Prosthesis according to claim 16, characterized in that the cuff (101) is attached to a rigid reinforcement or reinforcing member (121) provided shaft is attached. 18. Prosthesis according to claim 16 or 17 _? characterized in that anchoring cords (108) are attached to the other shaft (94). 19 · Prosthesis according to claim 18, characterized in that anchoring cords at the outer end of the cuff (101) ! (107) are attached. ¹ 20. Prosthesis according to claim 1 for the replacement of a diseased or j damaged elbow joint, characterized in that j that in one shaft and in part of the end of the Joint part with which the shaft is connected, a star-I res core member is embedded. tentanwalt 509813/0366