DE4428290A1 - Artificial replacement joint for human - Google Patents

Abstract

The joint parts (1,2,4), consisting of a ball (1) and socket, are spherical and/or toroidal and/or rotationally symmetrical. When inserted into place the joint parts enable the body fluid to reach the centre of the joint. The joint socket (2) has a hole (3), the centre of which is situated on the main force application line of the artificial joint in the base position. The hole is closed by a helical closure piece (12). A pressure-distribution body (4) is positioned so as to slide between the ball and socket.

Description

The present invention relates to an artificial joint to replace especially human joints, best starting from at least two joint parts with each other moving functional surfaces, namely a joint head and a socket, the joint being at least three Degrees of freedom of movement. In the case of three Joint parts, a joint head, a pressure distribution body and a socket, the joint has five Degrees of freedom.

In the known artificial joints, in particular artificial human joints, there is the problem of Friction. Since the joints do not circulate, the Don't fix a hydrodynamic liquid film form so that liquid lubrication does not start and dry friction is given. The body fluid can moreover, only those parts of the joint protruding from the joint socket Wet the joint head. This leads to high wear and thus to a limited shelf life of the artificial Joint parts. It also results from dry friction  abrasion of the sliding surfaces. The hereby Foreign particles generated pollute the living organism special way.

The present invention is based on the object to avoid the above disadvantages of artificial joint parts the, especially the durability of artificial man to increase joints.

According to the invention this is achieved in that the joint parts are designed such that access by the body fluid is reached in the center of the joint. Erfin According to such access of body fluid obtained by making a hole in the center of the socket is trained. This can make the body's joint fluid from the center into the joint space between the Penetrate joint parts. This hole is advantageous circular. When forming a joint with five degrees of freedom, as z. B. from the German Patent application P 39 08 958.4 is known, in which between Rod head and the socket a pressure distribution body is arranged by forming a hole in the socket and in the pressure distribution body the additional Lubrication possibility of the articular surfaces opened. It a sliding film is created, which is the abrasion between the Joint parts significantly reduced. Training a Hole in the socket also has the advantage that after a healing phase in the perforated area own, connective tissue and / or cartilaginous structures arise that not only reduce the friction problem, but also the stability of the socket in the pelvis enlarge.  

Furthermore, it can be advantageous according to the invention if the functional surfaces of the joint parts spherical and / or are toroidal and / or rotationally symmetrical and between the contacting functional surfaces in the used condition, d. H. in the functional position, a linear power transmission area is formed. Rotationally symmetric means that around an axis of rotation rotated contours are present. Hereby is invented in accordance with the same power transmission, the pressure on site The power transmission is significantly reduced at certain points, from which a significantly reduced material load and a ver followed by reduced material abrasion.

Thus, according to the invention, the lifespan of the artificial Joint parts increased considerably. The line-shaped force according to the invention, the transmission area can be circular, ellipsoidal, trapezoidal or horseshoe-shaped be trained. The formation of the linear force transmission range is essentially defined by the prevailing, special functional directions determined. According to the invention, a linear power transmission area obtained, for example, that a spherical designed articular surface with a toroidal design Articular surface or two toroidal shaped joint contact areas with each other. Training a line-shaped power transmission area according to the Erfin dung brings advantages both with artificial joints three as well as five degrees of freedom.

When creating a joint with five degrees of freedom, how it z. B. from German patent application P 39 08 958.4 is known in which between the joint head and the Ge Steering pan a pressure distribution body is arranged, can  the formation of the linear contact both between Joint socket and pressure distribution body as well between Pressure distribution body and joint head may be provided.

Thus the reduction in contact pressure according to the invention is particularly effective, it comes down to the relative dimension Nation of the radii of curvature of the articular surfaces on the Contact point. This dimensioning depends on the used materials. With metal-to-metal contact it may therefore be advantageous that the radii of curvature differ only slightly. The radius difference can for example less than 2% to a few parts per thousand of the be larger radius.

Advantageous embodiments of the invention are in the sub claims included.

Using those shown in the accompanying drawings The invention is explained in more detail in exemplary embodiments.

Show it:

Fig. 1 to Fig. 14 different embodiments of an artificial joint according to the invention in cross section through the pivot point of the respective joint.

In Fig. 1 it can be seen that an inventive artificial joint of an artificial joint head 1 and an artificial joint socket 2 is formed. When used as an artificial hip joint for humans, the socket 1 is the fossa and the joint head 2 is the condyle. In the embodiment shown, the socket 1 and the joint head 2 form a ball joint with three degrees of freedom, the pivot point of which is P. The radius R₁ of the joint head 1 and that of the socket 2 are almost the same size except for a small gap. A hole 3 is formed in the socket 2 in such a way that the center of the hole 3 lies in the main line of action of the artificial joint in the basic joint position. The main line of action is indicated by XX.

Through the hole 3 there is access to body fluid from the pelvic side. In addition, by filling the hole with connective or cartilage through the Einhei treatment process after surgery, the socket is of course expanded. Since this natural expansion of the socket is relieved in terms of force, because the joint force is distributed over the artificial part of the socket 2 , lubrication is also possible from the central area of the joint, which supports the formation of a lubricating film on the entire surface of the cone. Because at the same time as the wetted area of the joint head is enlarged through the hole, the area of the joint socket to be wetted is significantly reduced and in particular the respective lubrication path is restricted. This can significantly reduce wear due to abrasion in the joint.

The size of the hole can form 1/6 to 5/6 of the joint socket area up to the equator, so that the opening angle α can be changed accordingly. The size of the opening angle α depends on the material pairing of the materials from the joint head 1 and the socket 2 . The shape of the hole 3 is circular in the illustrated embodiment. However, the present invention is not limited to this, in particular an ellipsoidal, trapezoidal or else horseshoe-shaped hole shape can also be provided. Through this hole 3 , a linear force transmission area K _L between the joint head 1 and the socket 2 in the edge region of the hole is created, and thus the force transmission area is increased. With the same power transmission, the pressure at the location of the power transmission is reduced, and this results in a significantly reduced material load.

The joint shown in FIG. 1 is a ball joint with three degrees of freedom. The present invention is also applicable to a joint with five degrees of freedom, as is known from the German patent application P 39 08 958.4, reference being made to this patent in its entirety. The illustration in the accompanying FIG. 2 serves for explanation . In this joint shown, a pressure distribution body 4 , a so-called pressure distribution body 4 , is arranged between the joint socket 2 and the joint head 1 . The joint head 1 has a center of rotation M₁ and the socket 2 a center of rotation M₂. The circular, convex cutting contour of the joint head 1 has the radius R₁ and the concave, circular cutting contour of the Ge steering socket 2 has the radius R₂. The pressure distribution body 4 has a thickness D on the extension of the connecting line between M₁ and M₂. The pressure distribution body 4 has sliding surfaces 5 , 6 , the radii of which correspond to those of the abutting surfaces of the socket 2 and the joint head 1 . The radius R of the articulated axis path of the dimeric articulated chain with two articulated axes through the two rotation centers M 1 and M 2

R = R₂-R₁-D,

d. H. R has a positive amount so that R₂ <R₁ + D.

According to the invention, the joint socket 2 has a hole 3 which is designed in accordance with the hole 3 in FIG. 1 and can be arranged accordingly. Furthermore, it is appropriate if a hole 7 is also formed in the pressure distribution body 4 . This configuration of the socket 2 and the pressure distribution body 4 , the contact surfaces between the pressure distribution body 4 and the joint head are also lubricated from the center. This ensures a uniform formation of the lubricating film between all surfaces sliding on one another. By this design of the socket 2 and the Druckver distribution body 4 also linear force transmission areas in the edge region of the holes between the adjacent joint parts are generated with the already described reduction in pressure at the location of the respective force transmission and the resulting reduced material load.

In the following figures, the same parts as in Figs. 1 and 2 are provided with the same reference numerals.

In Fig. 3 is shown an embodiment of an artificial joint according to the invention. Here, the joint head 1 is spherical with a circular cutting contour and the radius R 1 in P. The joint socket 2 is, from a thematic point of view, a toroid. Its axis of rotation is XX. The circular sectional contours with the centers M₂₁ and M₂₂ and the associated radii R₂₁ and R₂₂ represent mathematically the toroid generating circle which is rotated to generate the toroidal surface around the ration axis XX. R₂₁ is therefore equal to R₂₂:

R₂₁ = R₂₂ = R₂.

R₂ is the radius of the toroid generating circle. Furthermore, R₁ <R₂ applies. R _T is an outer radius of the torus. It is defined by the point on the toroidal surface that has the greatest distance from the axis of rotation XX. The contact line K _L is a circle. The associated center lies on the axis of rotation XX of the toroid. The radius is R₃. β is a cone angle to the contact radius R₃. The joint socket can contain a hole in the lower part that allows liquid to enter, thus helping to increase the lubrication of the joint.

This joint of Fig. 3, which is drawn in the basic position, is in function a ball joint with three degrees of freedom. The joint head can only rotate about the pivot point P, which in this example is the geometric center of the joint head. The following also applies:

R _T = R₂- (R₂-R₁) · sin (β / 2);
R₃ = R₁ · sin (β / 2).

The angle β determines the position and size of the contact circle K _L. Its size depends on the materials chosen for the joint surfaces. As a rule, an angle β = 90 ° is particularly advantageous.

The radius difference δR = (R₂-R₁) between the toroid generating radius R₂ and the radius R₁ of the joint head ball is usually small. You can e.g. B. less than 2% to to be a few parts per thousand of R₂. In this embodiment the joint surface of the socket does not necessarily have to Be a torus. It can also be the concave upper section surface of another body with rotational symmetry.  

On the contact line for the radius difference δR between The radius of the sphere and the radius of curvature of the cutting contour are analogous the above statements.

FIG. 4 shows a variant of the joint design according to FIG. 3. Again, the joint head 1 is spherical with a circular cutting contour around the pivot point P, the circular cutting contour having the radius R 1 to P. The socket 2 represents a toroid. To generate it, the toroid-generating circle is rotated with R₂ about the axis of rotation XX. In the sectional view, two convex, circular pan contours 9 , 10 are formed with the centers M₂₁ and M₂₂ and the radius R₂. The contact line K _L is a circle. The associated center lies on the axis of rotation XX of the toroid. The radius is R₃. β is the cone angle to the contact radius R₃.

This joint of Fig. 4, which is drawn in the basic position, is in function a ball joint with three degrees of freedom. The joint head can only rotate about the pivot point P, which in this example is the geometric center of the joint head. If the resulting force adjuster is outside the angular range of β, the joint changes into a joint with five degrees of freedom. The following also applies:

R _T = R₂- (R₂ + R₁) · sin (β / 2);
R₃ = R₁ · sin (β / 2).

In Fig. 5, a further alternative of a fiction, modern artificial joint is shown. In this embodiment, the joint head 1 is toroidal, and the socket 2 is spherical. Your concave, arcuate cutting contour has the center P and the radius R₂. The toroidal joint head 1 has in the sectional view two circular, convex contours with the radii R₁₁ and R₂₂, which are given by the toroid-generating circle R₁.

R₁ = R₁₁ = R₁₂ (centers M₁₁, M₁₂).

Here, R₂ <R₁.

Otherwise the same radii and angles as in the previous figures.

In the socket 2 , in turn, a hole 3 is formed, in the manner described for FIG. 1. In this embodiment, the linear force transmission area is formed on the joint head. The following applies:

R _T = R₁₁ + (R₂-R₁₁) · sin (β / 2);
R₃ = R₂ · sin (β / 2).

This joint of FIG. 5, which is drawn in the basic position, is in function of a ball joint having three Liberty degrees. The joint head can only rotate around the pivot point P, which is also the geometric figures trical center of the acetabular cup 2 in this example. In principle, it also applies here that instead of a toroid, another rotationally symmetrical body can be used as the joint head 1 .

The radius difference δR = (R₂-R₁), between the radius R₂ the spherical socket and the radius R₁ des toroidal joint head is usually small. she can e.g. B. less than 2% to a few parts per thousand of R₂  his.

In this embodiment, the joint surface of the joint head 1 need not necessarily be a torus. It can also be the concave surface of another body with rotational symmetry in the sectional view. On the contact line for the radius difference δR between the radius of the sphere and the radius of curvature of the cutting contour, the above statements apply accordingly.

In Figs. 6 and 7, another embodiment of a joint according to the invention, consisting of the swivel head 1 and the socket 2 is shown. Here, both the joint head 1 and the socket 2 are toroidal. In the basic position ( FIG. 6), both toroids have the same axis of rotation XX. The axis of rotation P of this joint is not stationary, as can be seen from FIGS. 6 and 7, FIG. 7 showing the joint in a bent position. The joint head 1 shows in the sectional view two convex, circular contours with the center points M₁₁ and M₁₂ and the radii R₁₁ and R₁₂. They correspond to the circle R₁ = R₁₁ = R₁₂: this in turn is the circle that generates the toroid when rotating about the toroid axis XX. Accordingly, the sectional figure of the socket shows two concave, circular contours with the centers M₂₁ and M₂₂ and the radii R₂₁ and R₂₂. They correspond to the toroid generating circle R₂ = R₂₁ = R₂₂. The connecting line of the center points M₂₂ and M₁₂ intersects the connecting line of the center points M₂₁ and M₁₁ in the axis of rotation P.

L₂ is the coupling link between M₂₁ and M₂₂ and L₁ is that Coupling link between M₁₁ and M₁₂. δR₂ and δR₁ are the Connecting rods. The following applies:

(L₂-L₁) / (2 · (R₂-R₁)) = sin (β / 2).
R _1T = R₁-L₁ / 2.
R _2T = R₂-L₂ / 2.
δR₂ = δR₁ = δR.

The formation of this joint has the advantages that the linear contact areas on both joint surfaces hike. It also acts as a pump for the joint creates liquid, and there is a stable mechani equilibrium in the rest position (basic position) and self-stabilization when taking the individual Inflections.

In FIG. 8, a further alternative is shown a fiction, modern artificial joint. Here, both the joint head 1 and the socket 2 are formed as a toroidal body with a common axis of rotation XX in the basic position. The joint head 1 has, seen in cross section, two convex, circular contours with the center points M₁₁ and M₁₂ and the radii R₁₁ and R₁₂. They correspond to the circle R₁ = R₁₁ = R₁₂: this in turn is the circle that generates the toroid when rotating about the toroid axis XX. The socket 2 has two concave, circular contours in the sectional view with the centers M₂₁ and M₂₂ and the radii R₂₁ and R₂₂. They correspond to the circle R₂ = R₂₁ = R₂₂ with which the toroidal surface can be generated. The intersection P of the connecting line M₂₂M₁₂ with the Ver connecting line M₂₁M₁₁ is the axis of rotation of the system. The distances M₂₂M₁₂ = δR₂ and M₂₁M₁₁ = δR₁ are the same size. They are the connecting rods. The advantage of this joint variant is that the linear force transmission areas K _L migrate on both joint surfaces and there is a pumping action for the joint fluid, which in turn can penetrate into the joint through the hole 3 formed in the joint socket, as already described for the previous figures. However, this embodiment has an unstable equilibrium at rest. The following applies:

(L₂ + L₁) / (2 · (R₂ + R₁)) = sin (β / 2).

FIG. 9 shows a variant of FIG. 6, the joint head 1 being configured as the joint head according to FIG. 6. The acetabular cup is in accordance with the Ausbil dung form of Fig. 4 of two convex pan regions 9, 10 with the centers of M₂₁ and M₂₂ its circular sectional contours having the radii R₂₁ and R₂₂, which are of equal size and are larger than the radii of R₁₁ and R₁₂. This formation enables the linear contact areas to move on the joint parts, and a pumping action for the joint fluid is achieved. The joint shows a stable balance in the rest position. The other sizes known from the above figures also apply here. It is:

R₂₁ = R₂₂ = R₂; R₁₁ = R₁₂ = R₁
(L₂ + L₁) / (2 · (R₂ + R₁)) = sin (β / 2).

In Fig. 10, a further variant is shown of a fiction, modern artificial joint. Here, the joint head 1 corresponds to the design of Fig. 5. The design of the socket 2 corresponds to that of FIG. 7. The radii R₁₁ and R₁₂ are the same and smaller than the same size radii R₂₁ and R₂₂. In this embodiment, the linear contact areas migrate on both joint parts and a pumping effect for the synovial fluid is achieved. However, there is an unstable balance in the rest position. The following applies:

R₂₁ = R₂₂ = R₂; R₁₁ = R₁₂ = R₁
(L₂-L₁) / (2 · (R₂-R₁)) = sin (β / 2).

In Fig. 11, a further variant is shown of a hinge to the invention OF INVENTION artificial joint. Here again, both the joint head 1 and the socket 2 are formed as a toroidal body. The joint head 1 consists of a toroid such as the joint head in FIG. 5. The concave joint socket 2 represents a toroidal surface of the same type, the generating radius being larger. The joint socket can in turn have a hole 3 . Even with this joint design, the linear contact areas move on both joint parts, and there is a pumping action for the synovial fluid. There is a mechanically stable equilibrium in the rest position. The following applies:

R₂ = R₂₁ = R₂₂; R₁ = R₁₁ = R₁₂
(L₂-L₁) / (2 · (R₂-R₁)) = sin (β / 2).

All variants of FIGS. 1, 3-11 have three degrees of freedom of movement. About the size ratios of the contacting radii apply to all embodiments, the information that has been given to the embodiment of FIG. 3.

In principle, all ball joints can be expanded by connecting them in series or by inserting a second joint ball into a joint with three artificial joint parts. This creates a joint that has five degrees of freedom. Here, mechanical pressure stability of the pressure distribution body is always guaranteed when the pivot point P _{II of} the joint joint-pressure distribution body is "above" the pivot point P _I of the joint joint pressure distribution body-joint head: A compression force keeps the pressure distribution body mechanically stable between the joint head and the joint socket.

Fig. 12 and Fig. 13 show two embodiments of such a series circuit.

In Fig. 12 a series connection of two Kugelge joints with "linear" power transmission consisting of the types: toroidal joint socket - spherical joint head ( Fig. 3) and spherical joint socket - toroidal joint head ( Fig. 5) is shown.

Three artificial joint parts are created: joint socket 2 , movable pressure distribution body 4 , joint head 1 .

P _II is the pivot point of the acetabular ball joint, given by the joint surfaces of the joint parts 2 and 4 . The joint surface of the socket 2 is toroidal. The articulating surface of the pressure distribution body 4 is spherical and has the radius R₂ (corresponds to Fig. 3). The articular surface of the pressure distribution body 4 articulating with the joint head 1 is spherical. Your center is P _I , the associated radius is R₁. The articular surface of the articular head 1 is toroidal (corresponds to FIG. 5).

It is essential for a mechanically stable configuration that P _I , as seen from P _II , is displaced towards the joint part 2 , that is to say P _II "above" P _I. This makes it possible for joint part 4 to be pressed out in the case of compressive frictional connection.

If one holds joint part 2 , joint part 4 can rotate around P _II . Joint part 1 is taken along by this rotation, but can then additionally rotate about P _I.

The distance R between the centers of rotation P _II and P _I is constant and represents the chain link of the dimeric link chain. The following applies:

R = R₂-R₁-D.

D is the minimum distance between the circles around P _II and P _I with the radii R₂ and R₁ and thus the minimum thickness of the pressure distribution body.

For the radii of the toroidal articular surface of the joint head 1 and the toroidal articular surface of the Ge socket 2 apply mutatis mutandis the formulas of the execution forms according to FIG. 5 and FIG .

A particular advantage of this arrangement: The pressure distribution body 4 has only spherical articular surfaces. As a result, the contact rings K _L2 and K _L1 remain stationary on the joint surface of the socket 2 and also on that of the joint head 1 when the pressure distribution body 4 and the joint head 1 move. The result of this is that the transmission of force between the pressure distribution body 4 and the socket 2 can never strike a central hole in the socket.

A hole 3 in the joint surface of the socket has the advantage that synovial fluid can penetrate into the joint from below. This increases the lubrication. The hole can also be provided for the pressure distribution body.

FIG. 13 shows the connection in series of two ball joints with “linear” force transmission of the type: spherical joint socket - toroidal joint head according to FIG. 5.

Three artificial joint parts are created: joint socket 2 , pressure distribution body 4 , joint head 1 .

P _II is the pivot point of the acetabular ball joint, given by the joint surfaces of the joint parts 2 and 4 . The joint surface of the socket 2 is spherical and has the radius R₂. The articulating surface of the pressure distribution body 4 is toroidal. The articulating with the joint head 1 of the Druckver distribution body 4 is spherical. Your center is P _I , the associated radius is R₁. The joint surface of the joint head 1 is toroidal.

It is essential for a mechanically stable configuration that P _I , as seen from P _II , is displaced towards the joint part 2 . As a result, it is impossible for the joint part 4 to be pressed out in the case of a compressive frictional connection.

If one holds joint part 2 , joint part 4 can rotate around P _II . Joint part 1 is taken along by this rotation, but can then additionally rotate about P _I.

The distance R between the centers of rotation P _II and P _I is constant and represents the chain link of the dimeric link chain. The following applies:

R = R₂-R₁-D.

D is the minimum distance between the circles around P _II and P _I with the radii R₂ and R₁.

The formulas of FIG. 3 apply analogously to the radii of the toroidal surfaces of the joint head 1 and the pressure distribution body 4 on their joint surface facing the joint socket 2 .

The configuration according to the invention results from the Existence of the two articulating surfaces with one linear or band-shaped contact surface, the latter comes with elastic behavior of the two contact bodies created a cavity through the contact line (band) is delimited.

This cavity is variable in the case of elastic shape changes under loading / unloading cycles and / or through the corresponding shaping (see FIGS. 6 to 11). The variable cavity creates a suction / pumping effect for liquids that serve to lubricate the joints.

The variety of the possible combination is due to the Documentation of two further arrangements documented:

• a) Series connection of two ball joints with "linear" power transmission of the type: toroidal fossa - spherical condyle, corresponding to FIG. 3.
• b) Series connection of a ball joint with "line-shaped" power transmission of the type: toroidal fossa - spherical condyle (corresponding to FIG. 3) with a "normal", conventional ball joint as z. Currently used in endoprosthetics.

In Fig. 14 it is shown that it may be expedient to seal the hole 3 located in the socket 2 by means of a closure body 12, the closure body 12 z in the hole 3. B. can be screwed. This closure body 12 is used to keep the socket 2 and the hole 3 closed during insertion, so that no bone cement can penetrate into the area of the hole 3 and after the insertion and hardening of the bone cement, the closure body 12 is from the socket 3 unscrewed so that it then releases the hole 3 . The closure body 12 can also serve as a positioning aid when inserting the socket.

Claims (20)

1. Artificial joint to replace in particular human joints, consisting of at least two joint parts with mutually moving func tion surfaces, characterized in that the joint parts ( 1 , 2 , 4 ) spherical and / or toroidal and / or rotationally symmetrical and designed in such a way are that in the inserted state, ie in their functional position, access to body fluid is achieved in the center of the joint. 2. Artificial joint according to claim 1, characterized in that a hole ( 3 ) is formed in the socket ( 2 ), and preferably such that the center of the hole ( 3 ) in the main line of action of the artificial joint is in the basic position. 3. Artificial joint according to claim 1 or 2, characterized in that the joint parts consist of a joint head ( 1 ) and a Ge steering socket and a between the joint socket ( 2 ) and the joint head ( 1 ) slidably arranged pressure distribution body ( 4 ) and in Pressure distribution body is preferably a hole ( 7 ), the center of which lies in particular in the main force line of the joint in the basic position. 4. Artificial joint according to one of claims 1 to 3, characterized in that the size of the hole ( 3 ) in the socket ( 2 ) is 1/6 to 5/6 of the socket surface up to the equator. 5. Artificial joint according to one of claims 1 to 4, characterized in that the hole ( 3 ) located in the joint socket ( 2 ) with a closure body ( 12 ) in particular can be screwed ver. 6. Artificial joint according to one of claims 1 to 5, characterized in that functional surfaces of the joint parts ( 1 , 2 , 4 ) in the inserted state, ie in their functional position, a linear force transmission area K _L between the joint parts ( 1 , 2 , 4th ) exhibit. 7. An artificial joint according to one of claims 1 to 6, characterized in that the joint head (1) a center of rotation M₁ and the joint socket (2) having a rotation center M₂, wherein the circular, convex sectional contour of the joint head (1) the radius R ₁ and the concave, circular sectional contour of the socket ( 2 ) has the radius R₂ and the pressure distribution body ( 4 ) has a thickness D on the extension of the connecting line between M₁ and M₂ and the radius R of the articulated axis path of the dimeric articulated chain with two articulated axes through the two Center of rotation M₁ and M₂ results from R = R₂-R₁-D, where R₂ <R₁ + D. 8. Artificial joint according to one of claims 1 to 7, characterized in that in the socket ( 2 ) a hole ( 3 ) is formed, in such a way that the center of the hole ( 3 ) in the main line of action of the artificial joint in the Basic joint position lies, the edge of the hole forming the linear force transmission area. 9. Artificial joint according to claim 8, characterized in that in the pressure distribution body ( 4 ) a hole ( 7 ) is ausgebil det, so that between the pressure distribution body ( 4 ) and the adjacent joint parts ( 1 , 2 ) at the edge of the hole a linear force transmission area is generated, the hole ( 7 ) is advantageously larger in diameter than the hole ( 3 ) in the Ge steering socket ( 2 ). 10. Artificial joint according to claim 8, characterized in that the size of the hole ( 3 ) is a 1/6 to 5/6 of the articulated face up to the equator. 11. Artificial joint according to claim 7, characterized in that for an articulation between the joint head ( 1 ) and the pressure distribution body ( 4 ) a rotation center P _I and for the articulation between the pressure distribution body ( 4 ) and the joint socket ( 2 ) a rotation scene Trum P _{II is} present, the first articulation a radius R₁ (radius of the spherical surface of the corresponding pair of articular surfaces) and the second articulation a radius R₂ (radius of the spherical surface of the corresponding pair of articular surfaces), whose minimum distance is D, and wherein the radius R the articulated axis path of the dimeric articulated chain with the articulated axes through the two centers of rotation P _I and P _II results from R = R₂-R₁-D, where R₂ <R₁ + D ( Fig. 12, 13). 12. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) is spherical with a circular cutting contour and the radius R₁ around the pivot point P of the joint and the joint socket ( 2 ) has a toroidal shape of two itself has cutting, circular, concave cut contours with the center points M₂₁ and M₂₂ and the associated radii R₂₁ and R₂₂, where R₂₁ = R₂₂ and R₁ <R₂₁. 13. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) is spherical with a circular cutting contour around the pivot point P, and has the radius R₁, and that the joint socket ( 2 ) as part of a torus is formed, the section RT has the radius and the socket ( 2 ) from two convex socket surfaces ( 9 , 10 ) is formed with circular cut contours around the associated centers M₂₁ and M₂₂, the centers M₂₁ and M₂₂ and the pivot point P each lie in the corners of an isosceles triangle and the base line of the triangle is formed by the connecting line of M₂₁ and M₂₂, the radius R₂ being the circular sectional contour of the socket surface ( 9 , 10 ) and R₁ <R₂. 14. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) is toroidal and the joint socket ( 2 ) has a concave, circular arc-shaped cutting contour around the pivot point P with the radius R₂, the joint head ( 1 ) has two circular, on average convex cut contours with the radii R₁₁ and R₁₂ around the centers M₁₁ and M₁₂, where R₂ <R₁₁ = R₁₂. 15. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) and the joint socket ( 2 ) are toroidal, the axis of rotation P is not statio nary and the joint head ( 1 ) consists of two convex, circular Cutting contours with the centers M₁₁ and M₁₂ and the radii R₁₁ and R₁₂ is formed, wherein R₁₁ = R₁₂ and the socket ( 2 ) is formed from two con cave, circular cutting contours with the center points M₂₁ and M₂₂ and the radii R₂₁ and R₂₂, where R₂₁ = R₂₂ and the connecting line of M₁₁ and M₂₁ and the connecting line of M₁₂ and M₂₂ intersect at the pivot point P and meet the contact line K _L. 16. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) and the joint socket ( 2 ) are designed as a toroid-shaped body, the joint head ( 1 ) seen in cross section from two circular cut contours with the Centers M₁₁ and M₁₂ and the associated radii R₁₁ and R₁₂ is formed and the Ge steering pan ( 2 ) consists of two concave, circular sectional contours with the centers M₂₁ and M₂₂ and the radii R₂₁ and R₂₂, which are the same size and are larger than the radii R₁₂ and R₁₁, which in turn are the same size and the connecting line of M₁₁ and M₂₁ and the connecting line of M₁₂ and M₂₂ snow at the pivot point P and meet the contact line K _L. 17. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) and the joint socket ( 2 ) are designed as a toroid-shaped body, the joint head ( 1 ) consisting of two convex, circular sectional contours with the center points M₁₁ and M₁₂ and the radii R₁₁ and R₁₂ is formed, wherein R₁₁ = R₁₂ and the joint pan ne ( 2 ) is formed from two convex socket areas ( 9 , 10 ) with the centers M₂₁ and M₂₂ of their circular sectional contours and the radii R₂₁ and R₂₂, where R₂₁ and R₂₂ are the same size and larger than the radii R₁₁ and R₁₂. 18. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) and the joint socket ( 2 ) are designed as a toroid-shaped body, the joint head ( 1 ) having two circular, convex sectional contours with the radii R₁₁ and R₁₂ around the centers M₁₁ and M₁₂ and the socket ( 2 ) is formed from two convex socket areas ( 9 , 10 ) with the centers M₂₁ and M₂₂ with the radii R₂₁ and R₂₂, which are the same size, the radii R₁₁ and R₁₂ are the same size and smaller than the same size radii R₂₁ and R₂₂. 19. Artificial joint according to one of claims 1 to 11, characterized in that the joint head ( 1 ) and the joint socket ( 2 ) are designed as a toroid-shaped body, the joint head ( 1 ) having a cutting contour with the two center points M₁₁ and M₁₂ and the radii R₁₁ and R₁₂, where R₁₁ and R₁₂ are the same size and the joint socket ( 2 ) has two circular cut contours with the center points M₂₁ and M₂₂ and the radii R₂₁ and R₂₂, which are the same size, and the connecting line M₁₁, M₂₁ with the connecting line M₁₂, M₂₂ intersects at the pivot point P and these connecting lines meet the contact line K _L on the contact surfaces. 20. Artificial joint according to one of claims 1 to 11, characterized in that both the socket ( 2 ) and the joint head ( 1 ) are toroidal, and that the Druckver distribution body ( 4 ) has two spherical sliding surfaces ( 5 , 6 ) .