WO2021214606A1

WO2021214606A1 - Prosthesis component for an endoprosthesis

Info

Publication number: WO2021214606A1
Application number: PCT/IB2021/053109
Authority: WO
Inventors: Michael AUFREITER; Daniel SMOLEN
Original assignee: Aufreiter Michael; Smolen Daniel
Priority date: 2020-04-21
Filing date: 2021-04-15
Publication date: 2021-10-28
Also published as: AT523795A1

Abstract

A prosthesis component for an endoprosthesis for replacing an anatomical joint is disclosed, having at least one sliding surface element (6, 12) and a fastening part (1, 11) which is designed for fastening to a bone of a patient, wherein the sliding surface element (6, 12) can be fastened rigidly to the fastening part (1, 11), and the sliding surface element (6, 12), on a side (9) facing away from a sliding surface (8) of the sliding surface element (6, 12), has at least one recess (10) in which a magnet element (20) is at least partially received. Also disclosed is a prosthesis mating component with a sliding surface mating element (13), having a ferromagnetic material and also a sliding surface element and an endoprosthesis.

Description

Prosthetic component for an endoprosthesis

The present invention relates to a prosthesis component for an endoprosthesis to replace an anatomical joint, at least with a sliding surface element and a fixing part designed to be fixed to a patient's bone, a prosthesis counter component for use with a prosthesis component according to the invention, a sliding surface element for use in a prosthesis component according to the invention and a Endoprosthesis for replacing an anatomical joint connection comprising a prosthesis component according to the invention.

Endoprostheses of the type mentioned at the outset are already being used in large numbers in the accident surgery care of patients and especially in orthopedic surgery to replace joints in the human body that have been destroyed due to pathological signs of wear and tear or also due to bone tumors. Such endoprostheses usually consist of a prosthesis component with a fixing part and a sliding surface element and a corresponding prosthesis counter component with a fixing part and a sliding surface counter element, the fixing parts being attached to the bone whose joint connection is to be replaced and the sliding surface (counter) elements after Attaching the fixing parts can be firmly or loosely connected to these.

The sliding surfaces (counter) elements are mostly made of abrasion-resistant plastic, metal or ceramic and can be replaced if they are worn out or break prematurely. In the case of arthrosis, the pathological, degenerative signs of wear and tear relate to the progressive and extensive loss of cartilage on the joint surfaces, which leads to considerable pain when moving the affected joint. The patients experience this as a serious limitation of their mobility and thus their way of life. If the wear and tear causes a certain degree of restriction, the replacement of the affected joint is increasingly being taken, especially in industrialized countries, whereby in most cases a significant improvement in well-being and joint function can be achieved. Endoprostheses of this type have meanwhile been developed and approved for a number of anatomical joints, the replacement of the hip joint and the knee joint in particular being carried out frequently and with great success, and the results of replacing the shoulder joint nowadays also show very good results with increasing numbers of implantations .

For this purpose, the affected joint parts are removed in a controlled manner in preparation for the implantation of the endoprosthesis and the prosthesis components are inserted. When replacing the knee joint or the hip joint mentioned, good stability is usually achieved due to their functionality with relatively limited degrees of freedom of movement and the corresponding geometric conditions of these joints and, especially in the case of the knee joint, due to the anatomical stabilization by ligaments. However, instabilities of the endoprostheses represent a known and statistically well-documented type of complication even with good anchoring of the fixing parts or the prosthesis components On the one hand it is painful and on the other hand, in addition to the impairment of mobility associated with dislocation, there is a risk of damage to the ligament apparatus, which is why pronounced instabilities sometimes result in revision surgery to correct them, which naturally has considerable disadvantages. On the one hand, like any operation, a revision operation harbors the dangers associated with the anesthesia as well as a renewed risk of infection and, on the other hand, the reopening of the joint capsule is also associated with damage, with further scarring of the joint capsule possibly leading to the fear of a suboptimal result of the revision operation .

Another problem with existing endoprostheses, particularly in the case of shoulder endoprostheses, is that the prosthesis parts or prosthesis components can collide with anatomical structures such as the shoulder blade while moving. This is extremely uncomfortable and mostly painful for the patient and, moreover, quickly leads to notches on the bone and consequently to loosening of prosthesis parts, which of course must be avoided at all costs.

It is therefore an object of the present invention to provide an improved prosthesis component with which a tendency towards instability of the corresponding joint connection and the tendency of the prosthesis to collide with anatomical structures can be reduced or prevented.

To solve this problem, according to the invention, starting from a prosthesis component of the type mentioned at the outset, the sliding surface element can be rigidly fixed to the fixing part and the sliding surface element has on a sliding surface of the Sliding surface element facing away from the side on at least one recess in which a magnetic element is at least partially received. With such a

Prosthesis component can be prevented from a possible instability by providing the possibility of a magnetic coupling of the prosthesis component according to the invention with a prosthesis countercomponent, whereby the prosthesis component according to the invention can only be used in the case of a revision, since it can magnetically interact with an already existing ferromagnetic prosthesis countercomponent in order to create a suitable coupling force between to apply the prosthesis component and the prosthesis counter component. Dislocation tendencies are counteracted in this way. Because the at least one magnetic element is at least partially accommodated in the sliding surface element, the magnetic element can be positioned very close to the sliding surface of the sliding surface element, which contributes to an effective magnetic coupling when the prosthesis component according to the invention is used together with a ferromagnetic prosthesis countercomponent.

A further improvement in stability is achieved by rigidly fixing the sliding surface element, which serves to prevent the sliding surface element from lifting out of the fixing part or from twisting.

According to a preferred embodiment of the present invention, the sliding surface for forming a joint socket is designed spherically concave. This design of the sliding surface serves primarily to make the prosthesis component according to the invention suitable for a hip endoprosthesis or an inverse shoulder endoprosthesis. Because of the great degree of freedom of movement that they must provide for a satisfactory function in the patient, in particular Shoulder prostheses have a relatively strong tendency to instability. This is due to the fact that, on the one hand, the shoulder joint provides the greatest degree of freedom of movement and therefore, with regard to the geometry of the joint socket, a relatively small depth and size of the socket must be sufficient, and on the other hand, the joint socket, which is used in a inverse shoulder prosthesis is formed on the humerus, must be relatively small in order to avoid collisions of the humeral portion, which in this case is formed by the prosthesis component according to the invention, with the shoulder blade. The present invention is therefore particularly suitable for the formation of these endoprostheses.

To further avoid collisions of the prosthesis component according to the invention, in particular with anatomical structures and in particular with the shoulder blade, the prosthesis component according to the invention is preferably developed in such a way that the sliding surface element has at least one indentation on the circumference based on a circular circumferential contour.

In this case, the sliding surface element is preferably designed to be rigidly fixed in a position that prevents the prosthesis component from colliding with the shoulder blade below the prosthesis countercomponent, ie in the area of the infraglenoidal tubercle, if this is caused by wear and tear or tumor-related Joint parts affected by osteolysis are prevented by the indentation with its opening being oriented approximately along the axis of the humerus in a distal direction, ie in the direction of the diaphysis.

In order to make the sliding surface element even smaller and thus even more advantageous in terms of avoiding collisions, the invention is preferred to that effect developed further that, starting from a circular circumferential contour, the sliding surface element has a plurality of indentations on the circumference, which are preferably arranged uniformly distributed around the circumference. In particular, it is further preferred in this context that the sliding surface element, starting from a circular circumferential contour, has three indentations on the circumference, which are preferably arranged around the circumference offset by 120 °. In this case, the sliding surface element has an approximately clover-shaped circumferential contour and thus provides a central area and three projections for the prosthesis component according to the invention to rest on the prosthesis countercomponent.

This enables a stable support of the prosthesis component according to the invention on the prosthesis counter component while eliminating unneeded areas to reduce the size of the prosthesis component according to the invention in order to minimize the aforementioned risk of collisions.

In order to allow the collision-minimizing design and size of the sliding surface element of the prosthesis component according to the invention to come into full effect, the prosthesis component according to the invention is preferably developed in such a way that the fixing part has a circumferential contour corresponding to the sliding surface element. The circumferential contour of the fixing part thus essentially follows the circumferential contour of the sliding surface element or the peripheral contour of the fixing part is adapted to a circumferential contour that is to be achieved on the metaphyseal or diaphyseal part of the fixing part, where the fixing part usually has a metaphyseal and a / or diaphyseal anchored shaft. The fixing part can be formed in one piece with a shaft, but as a rule the shaft is a separate part in different Lengths and thicknesses positively and / or non-positively connectable to an epiphyseal portion of the fixing part.

For the stabilization by magnetic coupling, it is provided according to a preferred embodiment of the present invention that in each case a recess for at least partially receiving a magnetic element is arranged in a projection of the sliding surface element formed between indentations. In this way, the magnetic elements are arranged relatively far outwards on the sliding surface element, whereby the magnetic force comes into effect correspondingly far outward, which counteracts tilting of the sliding surface element relative to the prosthesis countercomponent better than is the case if, for example, the magnetic force is only in the central area of the sliding surface element comes into play.

According to another preferred embodiment, the sliding surface element is designed to form a joint head with a spherically convex sliding surface and can be rigidly fixed to the fixing part with the interposition of an intermediate piece, preferably made of soft iron to form a soft iron core. In this case, the sliding surface element is preferably concave on the side opposite the sliding surface, the cavity being essentially completely filled by the intermediate piece in order to provide contact with the sliding surface element and corresponding fastening means for fastening the intermediate piece to the fixing part. The sliding surface element can be fixed to the fixing part in any suitable manner, but this is preferably done by means of a latching connection. A number of materials can be used to form the at least one magnetic element and the material is to be selected in connection with the present invention in such a way that with the at least one magnetic element, preferably with a plurality of magnetic elements, depending on the dimensions of the at least one magnetic element and its distance from a corresponding prosthesis counter component a magnetic coupling force of the prosthesis component according to the invention with a corresponding one

Prosthesis counter component of 10 N to 50 N, preferably 15 N to 35 N, more preferably 20 N is achieved. For this purpose, it is provided according to a preferred embodiment of the present invention that the at least one magnetic element is formed from a material selected from the group of rare earth magnets, in particular consisting of neodymium and samarium magnets.

To increase the magnetic coupling force through a targeted alignment of the magnetic field, it can be provided that the sliding surface element further has at least one recess on a side facing away from a sliding surface thereof for at least partially receiving at least one soft iron core. Preferably, the recess for at least partially receiving at least one soft iron core is arranged centrally in the sliding surface element and surrounded by the plurality of recesses for at least partially receiving a magnetic element in a projection of the sliding surface element formed by indentations. With such a soft iron core, the magnetic field of the at least one magnetic element, preferably the plurality of magnetic elements, can be aligned and strengthened so that a sufficiently high magnetic coupling force, for example to one, is also possible with relatively small magnetic elements to be able to provide metallic joint head as a prosthesis counter component.

The rigid fixing of the sliding surface element on the fixing part can take place in the most varied of ways in connection with the present invention, but it is preferred that the sliding surface element can be fixed on the fixing part by means of a latching connection. For this purpose, sliding surface element and fixing part have corresponding locking elements which, after anchoring the fixing part, for example in the humerus of a patient, can be brought into operative connection with one another by placing the sliding surface element on the fixing part and for example by a targeted blow with a surgical hammer.

In connection with the present invention, the fixing part is usually made of surgical steel or titanium and can preferably have a, preferably plasma-sprayed, coating of hydroxyapatite for better anchoring in the metaphysis and / or diaphysis. The sliding surface element is usually formed from a plastic, in particular from polyethylene.

Depending on the required size of the at least one magnetic element and, as a result, only partial reception in the at least one recess of the sliding surface element, it may be necessary to provide space for the at least one magnetic element in the fixing part as well. The prosthesis component according to the invention is therefore preferably developed in such a way that the fixing part has at least one recess, preferably a plurality of recesses for partially receiving magnetic elements and / or at least one soft iron core, the at least one Recess is arranged on the fixing part such that it is aligned with the at least one recess of the sliding surface element in the fixed state of the sliding surface element.

The shape of the prosthesis countercomponent according to the invention is adapted to the sliding surface element of the prosthesis component in order to achieve the most flat possible contact of the sliding surface element on the prosthesis countercomponent and comprises a sliding surface counter element and a fixing part designed to be attached to a patient's bone, the sliding surface counter element having a ferromagnetic material. In connection with the present invention, it is basically conceivable to also arrange corresponding magnetic elements in the prosthesis countercomponent, but despite its suitability for endoprostheses for various anatomical joints, the present invention is directed with particular attention to an, in particular inverse, shoulder end prosthesis, for which the formation of the Prosthetic mating component made from ferromagnetic material alone has a decisive advantage. Compared to the high mobility in the form of a multiaxial pivoting of a patient's arm, which is to be achieved with a shoulder endoprosthesis, the use of two opposing magnetic prosthesis components would severely limit the mobility in a plurality of directions due to the magnetic force directed through the two magnetic elements. For example, one could move the arm forwards and backwards, but not spread it or rotate it. If the patient were to force the two last-mentioned movements, the use of magnetic elements in the prosthesis countercomponent would result in an increasing deflection of the prosthesis in one or the other axis There is a tendency to repel between the magnetic elements of the prosthesis component according to the invention and those in the prosthesis countercomponent, which would run counter to the purpose of the present invention. If only one ferromagnetic material is used in the prosthesis countercomponent, the attraction of the magnetic elements of the prosthesis component according to the invention remains more or less the same regardless of the deflection, but it is ensured in any case that there is no repulsion and no opposing polarity between the magnetic elements of the prosthesis component according to the invention and those in the prosthesis countercomponent. In addition, the provision of magnetic elements in the prosthesis countercomponent would also bring about a preferred alignment of the prosthesis component with respect to the prosthesis countercomponent, so that the patient would feel an undesirable tendency for the endoprosthesis to reset, which is not the case with a sliding surface counter element that only has a ferromagnetic material and explicitly no magnetic element is watching.

According to a preferred embodiment of the present invention, the sliding surface counter element is designed to be spherically convex to form a joint head or spherically concave to form a joint socket, corresponding to the sliding surface element. This embodiment of the sliding surface counter element primarily serves to make the prosthesis counter component according to the invention suitable for a hip endoprosthesis or an inverse shoulder endoprosthesis.

Here it is conceivable, for example, that the sliding surface counter-element is designed spherically convex and hollow to form a joint head, which is the case with corresponding production brings a weight and material saving with it.

With regard to the preferred embodiment discussed above, according to which the sliding surface counter element has a ferromagnetic material, it is particularly preferred that the ferromagnetic material is arranged uniformly in the joint head or the joint socket, the joint head or the joint socket preferably being made essentially from the ferromagnetic material. In the preferred case in which the sliding surface counter element is designed to be spherically convex and hollow to form a joint head, the ferromagnetic material can be contained as ferrofluid in the hollow joint head.

There are a number of materials for the ferromagnetic material in question and the material is to be selected in connection with the present invention in such a way that with the ferromagnetic material, depending on the dimensions of the prosthesis countercomponent and its distance to a corresponding prosthesis component, a magnetic coupling force of the prosthesis countercomponent according to the invention with a corresponding prosthesis component of 10 N to 50 N, preferably 15 N to 35 N, more preferably 20 N is achieved.

For this purpose, it is provided according to a preferred embodiment of the present invention that the ferromagnetic material is selected from the group consisting of, preferably corrosion-resistant, ferritic, martensitic, magnetically soft steels and ferrofluid.

Depending on the requirements, the ferromagnetic material can be a material that does not have the biocompatibility and / or abrasion resistance required for endoprostheses. Of the Joint head according to the invention or the joint socket according to the invention can therefore be coated with a material selected from the group consisting of titanium and implant steels or coated with a material selected from the group consisting of TiN, ZrN, CrN, AlTiN and DLC, as is a preferred embodiment of the present invention Invention corresponds. In connection with the present invention, DLC means “diamond like carbon”.

The invention is explained in more detail below with reference to an exemplary embodiment shown schematically in the drawing. In this show

1 shows a perspective illustration of a fixing part of a prosthesis component according to the invention,

FIG. 2 is a plan view of the fixing part according to FIG. 1,

3 shows a perspective illustration of a sliding surface element of an inventive

Prosthesis component for a fixing part according to Figures 1 and 2,

FIG. 4 shows a plan view of the sliding surface element according to FIG. 3,

Fig. 5 is a sectional view along the line A-A of Fig. 4,

6 shows a perspective illustration of an alternative fixing part of a prosthesis component according to the invention,

7 shows a perspective illustration of an alternative sliding surface element of a prosthesis component according to the invention,

Figure 8 is a sectional view along the line A-A of Figure 7, 9 shows a prosthesis counter component according to the present invention in section,

10 shows an exploded view of an endoprosthesis according to the invention,

11 shows a sectional illustration of an alternative embodiment of the prosthesis component and FIG

FIG. 12 shows a perspective illustration, partially in section, of the embodiment according to FIG. 11.

In Fig. 1, the reference numeral 1 denotes a fixing part for a prosthesis component according to the invention and it can be seen that the fixing part 1 is a

Has fastening portion 2, for example in the form of a cone for connecting the fixing part 1, for example with a prosthesis shaft. The type of connection is preferably that of a press fit connection. The fixing part 1 can have a special coating, for example made of hydroxyapatite, to support osseointegration. Starting from a circular circumferential contour, the fixing part 1 has a plurality of indentations 3 and projections 3 'between the indentations 3 and also bearing surfaces 4 for a sliding surface element or recesses 4 for at least partial accommodation of magnetic elements not shown in FIG. In the view according to FIG. 2, the indentations 3 and the projections 3 'can be seen more clearly and it can also be seen that drill holes 5 are provided for positive connection by screwing the fixing part 1 to a prosthesis shaft. The fixing part 1 is shaped in accordance with the sliding surface element 6 shown in perspective in FIG.

The sliding surface element 6 also has a plurality of indentations 7 and projections 1 'and, as the most essential element, forms a sliding surface 8, which is a Has spherically concave geometry and which forms a bearing surface for a joint head.

In the illustration according to FIG. 4 it can be seen that on the side 9 of the

Sliding surface element 6 a plurality of recesses 10 are provided for at least partially receiving magnetic elements. Furthermore, a recess 10 'for at least partially receiving at least one soft iron core or a magnet element is arranged centrally in the sliding surface element 6 and surrounded by the plurality of recesses 10 for at least partially receiving one magnet element in each case in the areas of the projections 7'. The fixing part 1 and the sliding surface element 6 have latching elements which can be brought into operative connection with one another.

In FIG. 5, two of the recesses 10 are shown cut away and it can be seen that the recesses 10 extend relatively close to the surface of the sliding surface 8 in order to bring the magnetic elements as close as possible to the prosthesis countercomponent.

The alternative fixing part 11 shown in FIG. 6 has only an indentation 3 and a support surface 4 for a sliding surface element or a recess 4 for a magnetic element. The corresponding sliding surface element 12 shown in FIG. 7 also has an indentation 7 and, on the side 9 opposite the sliding surface 8, has a central recess 10 for at least partial accommodation of a magnetic element, as can be seen in FIG. 8.

In FIG. 9, a fixing part of a prosthesis counter component 13 is denoted by 14. A Sliding surface counter element 15 is spherically convex and in this way forms a joint head which can interact with one of the prosthesis components described above to form an endoprosthesis. The fixing part 14 can be connected to a prosthesis shaft (not shown in FIG. 9) via a cone 19. With 16 a core of the sliding surface counter element 15 is designated, which consists entirely of a ferromagnetic material and is connected to the fixing part 14 via bores and screws 17. With a coating made of a biocompatible material is designated. As described above, the core 16 can also be formed by a ferrofluid in the cavity formed by the coating 18. The prosthesis counter component 13 has no recesses for magnetic elements.

In Fig. 10 all essential parts of an endoprosthesis 21 according to the invention for replacing an anatomical shoulder joint are shown and it can be seen that in addition to the components already described and in particular to the fixing part 1 and the sliding surface element 6, a plurality of magnetic elements 20 are provided, which at least are partially received in the recesses 10. As a result of the sliding surface element 6, these magnetic elements 20 interact with the prosthesis countercomponent 13 to form a magnetic force and thus stabilize the endoprosthesis 21 against dislocation. A soft iron core or a further magnetic element is designated by the reference symbol 20 '. The reference number 22 denotes a prosthesis socket.

In FIG. 11, an alternative embodiment of the present invention is shown in section and components that correspond to one another are given the same reference numerals as referred to in the previous figures. In this embodiment, the sliding surface element 6 is designed to form a joint head with a spherically convex sliding surface 8. The sliding surface element 6 is furthermore with the interposition of a, preferably made of soft iron to form a soft iron core,

The intermediate piece 23 is rigidly fixed to the fixing part 1 and has recesses 10 for at least partial accommodation of magnetic elements 20. With such a soft iron core, the magnetic field of the at least one magnetic element, preferably the plurality of magnetic elements, can be aligned and strengthened so that it is possible to provide a sufficiently high magnetic coupling force even with relatively small magnetic elements. Instead of magnetic elements, soft iron elements can sometimes also be accommodated in the recesses. The intermediate piece 23 is fastened to the fixing part 1 with fastening means in the form of a bore 24 and a screw 25, although a threaded pin on the fixing part 1 or a self-locking tapered connection between the fixing part 1 and the intermediate piece 23 is also conceivable. Because the sliding surface element 6 has recesses 10 on the side opposite the sliding surface 8 for at least partial accommodation of magnetic elements 20, the magnetic elements 20 can be inserted into the sliding surface element 6 from this rear side and fixed between the sliding surface element 6 and the intermediate piece 23. For this purpose, the intermediate piece 23 also has a plurality of recesses 4 for partially receiving the magnetic elements 20, the recesses 4 on the intermediate piece 23 being arranged in such a way that, when the sliding surface element 6 is fixed, they are aligned with the recesses 10 of the sliding surface element. The sliding surface element 6 is Fixed to the fixing part 1 by means of a latching connection.

In Fig. 12 it can be seen that the recesses 10 for the magnet elements 20 have a radial, star-shaped course and thus allow the attachment of relatively large magnet elements 20 in order to ensure a high holding force between the prosthesis component and a corresponding prosthesis countercomponent.

Claims

Patent claims:

1. Prosthesis component for an endoprosthesis to replace an anatomical joint, at least with a sliding surface element (6, 12) and a fixing part (1, 11) designed to be fixed to a patient's bone, the sliding surface element (6, 12) being attached to the fixing part ( 1, 11) can be rigidly fixed and the sliding surface element (6, 12) has at least one recess (10) in which a magnetic element (20) is located on a side (9) facing away from a sliding surface (8) of the sliding surface element (6, 12) is at least partially included.

2. Prosthesis component according to claim 1, characterized in that the sliding surface (8) is designed spherically concave to form a joint socket.

3. Prosthesis component according to claim 1 or 2, characterized in that the sliding surface element (6, 12), starting from a circular circumferential contour, has at least one indentation (7) on the circumference.

4. Prosthesis component according to claim 1, 2 or 3, characterized in that the sliding surface element (6, 12) starting from a circular circumferential contour has a plurality of indentations (7) on the circumference, which are preferably arranged evenly distributed around the circumference.

5. Prosthesis component according to one of claims 1 to 4, characterized in that the sliding surface element (6, 12) starting from a circular circumferential contour three Has indentations (7) on the circumference, which are preferably arranged offset around the circumference by 120 °.

6. Prosthesis component according to claim 3, 4 or 5, characterized in that the fixing part (1, 11) has a circumferential contour corresponding to the sliding surface element (6, 12).

7. Prosthesis component according to claim 4, 5 or 6, characterized in that in each case a recess (10) for at least partially receiving a magnetic element (20) in a respective projection (7 ') of the sliding surface element (6, 12) formed between indentations (7) ) is arranged.

8. Prosthesis component according to claim 1, characterized in that the sliding surface element (6, 12) is designed to form a joint head with a spherically convex sliding surface (8) and with the interposition of an intermediate piece (23) preferably made of soft iron to form a soft iron core. can be rigidly fixed to the fixing part (1).

9. Prosthesis component according to one of claims 1 to 8, characterized in that the at least one magnetic element (20) is formed from a material selected from the group of rare earth magnets, in particular consisting of neodymium and samarium magnets.

10. Prosthesis component according to one of claims 1 to 9, characterized in that the sliding surface element (6, 12) on one of the sliding surface (8) of the same facing away from the side (9) further at least one recess (10 ') for at least has partial inclusion of at least one soft iron core (20 ').

11. Prosthesis component according to one of claims 1 to 10, characterized in that the sliding surface element (6, 12) can be fixed by means of a latching connection on the fixing part (1, 11).

12. Prosthesis component according to one of claims 1 to 11, characterized in that the fixing part (1, 11) or the intermediate piece (23) has at least one recess (4), preferably a plurality of recesses (4) for partially receiving magnetic elements (20 ) and / or at least one soft iron core (20 '), the at least one recess (4) being arranged on the fixing part (1, 11) or the intermediate piece (23) in such a way that it is in the fixed state of the sliding surface element (6, 12) is aligned with the at least one recess (10, 10 ') of the sliding surface element (6, 12).

13. Prosthetic mating component for use with a prosthetic component according to one of claims 1 to 12, comprising a sliding surface mating element (15) and a fixing part (14) designed for fixing to a bone of a patient, the sliding surface mating element (13) having a ferromagnetic material.

14. Prosthesis counter component according to claim 13, characterized in that the sliding surface counter element (15) is designed to form a joint head spherically convex or to form a joint socket spherically concave corresponding to the sliding surface element (6, 12).

15. Prosthetic mating component according to claim 14, characterized in that the ferromagnetic material is arranged uniformly in the joint head or the joint socket, the joint head or the joint socket preferably being made essentially from the ferromagnetic material.

16. Prosthetic counter component according to claim 13, 14 or 15, characterized in that the ferromagnetic material is selected from the group consisting of, preferably corrosion-resistant, ferritic, martensitic, magnetically soft steels and ferrofluid.

17. Prosthesis counter component according to one of claims 13 to 16, characterized in that the joint head or the joint socket is coated with a material selected from the group consisting of titanium and implant steels or with a material selected from the group consisting of TiN,

ZrN, CrN, AlTiN and DLC is coated.

18. Sliding surface element for use in a prosthesis component according to one of claims 1 to 12.

19. Endoprosthesis to replace an anatomical one

Articulation connection comprising a prosthesis component according to one of Claims 1 to 12 and a prosthesis counter component according to one of Claims 13 to 17.