WO2001085068A1

WO2001085068A1 - Endoprosthesis part for use in joint replacement, use of the same and production method therefor

Info

Publication number: WO2001085068A1
Application number: PCT/EP2001/005070
Authority: WO
Inventors: Markus Schwarz; Henrik Schroeder-Boersch
Original assignee: Universität Heidelberg
Priority date: 2000-05-08
Filing date: 2001-05-04
Publication date: 2001-11-15
Also published as: AU6028001A; DE10022260A1; DE10022260C2

Abstract

The invention relates to an endoprosthesis part for use in joint replacement that comprises a body (6) and a multitude of force-absorbing areas (2), which are provided with the body (6) as one piece and which can absorb a force acting upon the endoprosthesis part, in particularly, when inserting the endoprosthesis into a bone. The inventive endoprosthesis part also comprises osseointegrative and/or osseoinductive or osseoconductive areas (4), which enable an osseous growing-in of the endoprosthesis part or stimulate or promote bone growth. The invention also relates to the use of the inventive endoprosthesis part as a cotyloid cavity, which is anchored without the use of cement and which is provided for accommodating a corresponding femoral head. The invention additionally relates to a production method for endoprosthesis parts involving the following steps: preparing a body (6) with force-absorbing areas (2) that are provided therewith as one piece; preparing areas (4) with osseointegrative and/or osseoinductive or osseoconductive properties, and; joining the body (6) to the osseointegrative and/or osseoinductive or osseoconductive areas (4).

Description

The present invention relates to an endoprosthesis part for the joint replacement, to the use of the endoprosthesis part according to the invention and to a production method for endoprosthesis parts according to the invention.

Until now, endoprosthesis parts for artificial cement-free joint replacement have been manufactured using an inlay technique. Such an endoprosthesis part is e.g. in EP 0 743 050. Here a ceramic 1 nert in a metal bowl e.g. anchored from titanium. The ceramic insert has a spherical concavity to accommodate the ball head of a joint. Here, the good tribological properties of the ceramic are used. The metal shell surrounding the ceramic insert takes on the task of bony integration of the endoprosthesis part in order to ensure good stability of the endoprosthesis part over several years. Due to the dynamic loading of the joint, however, the connection point between the ceramic and the metal shell is heavily loaded, which results in a reduced service life of the endoprosthesis part.

Furthermore, endoprosthesis parts have been proposed which consist entirely of a ceramic and thus solve the problem of the connection between ceramic and metal. However, such endoprosthesis parts have the disadvantage that the bony healing does not take place, or takes place only insufficiently, and therefore long-term stability of the endoprosthesis part cannot be guaranteed, which in turn results in the endoprosthesis part having a limited shelf life.

It is therefore an object of the invention to enable a long service life and, at the same time, good bony healing or osseointegration of an endoprosthesis part.

This object is achieved by an endoprosthesis part according to claim 1, a use of the endoprosthesis part according to the invention according to claim 18 and a manufacturing method of the endoprosthesis part according to claim 19. Preferred embodiments are defined in the dependent subclaims.

According to the invention, an endoprosthesis part, in particular an artificial acetabular cup or acetabular cup, is provided for the joint replacement, which body can absorb force areas, which are integrally formed with the body and which can absorb a force acting on the endoprosthesis part, in particular when inserting the endoprosthesis part into a bone osseointegrative and / or osseoinductive or osseoconductive areas, which enable bony ingrowth or osseointegration of the endoprosthesis part or stimulate or promote bone growth.

The force absorption areas serve to e.g. absorb forces occurring when the endoprosthesis part is hammered into a prepared bone bed and thus essentially protect the osseointegrative and / or osseoinductive or osseoconductive areas from damage. Furthermore, the force absorption areas preferably ensure the primary stability of the endoprosthesis part within the bone in the first time after insertion. The osseointegrative and / or osseoinductive or osseoconductive areas promote the bony ingrowth of the endoprosthesis part and thereby enable good secondary stability, so that the prosthesis part is anchored in the long term.

The body with the force absorption areas and the osseointegrative and / or osseoinductive or osseoconductive areas are preferably provided in a monoblock structure in the endoprosthesis part according to the invention. It has been found that junctions between different materials often represent a weak point in endoprosthesis parts. The life of the endoprosthesis part according to the invention can be increased by the monoblock structure. The endoprosthesis part according to the invention preferably has at least three force absorption areas, which enable a stable support of the endoprosthesis part.

Furthermore, the force absorption areas are preferably distributed circumferentially on the endoprosthesis part, so that the forces e.g. be distributed evenly over the force absorption areas when inserting.

In a preferred embodiment, the osseointegrative and / or osseoinductive or osseoconductive regions are arranged between two adjacent force absorption regions. Osseointegrative and / or osseoinductive or osseoconductive areas often have a low stability with respect to the pressure loads occurring during insertion and in the first time after insertion. These loads can be absorbed by the force absorption areas, whereby the osseointegrative and / or osseoinductive or osseoconductive areas are protected.

The force absorption areas preferably project over the osseointegrative and / or osseoinductive or osseoconductive areas. In this way, the osseointegrative and / or osseoinductive or osseoconductive areas can additionally be protected against stresses occurring during insertion, the elastic properties of the bone in particular being exploited.

In a preferred embodiment, the force absorption areas project by approximately 0.3 mm to 1 mm in relation to the osseointegrative and / or osseoinductive or osseoconductive areas. This range of values has proven to be particularly suitable for the difference in height between the force absorption areas and the osseointegrative and / or osseoinductive or osseoconductive areas. The force absorption areas preferably have, at least in part, a thread or thread areas formed thereon. This offers the advantage of an additional positive and frictional primary anchoring of the endoprosthesis part.

In a preferred embodiment, devices for securing against rotation are provided on the force absorption areas, which essentially prevent the inserted endoprosthesis part from twisting. Thus, the endoprosthesis part can be prevented from rotating in the bone bearing in the first time after insertion before the secondary anchoring of the endoprosthesis part is formed by bone healing.

The body of the endoprosthesis part preferably has good tribological properties on a side facing a joint. This enables an advantageous interaction of the endoprosthesis part with a joint counterpart to be achieved.

The body and the force-absorbing areas are preferably formed from a hard ceramic. Hard ceramics on the one hand have very good tribological properties, on the other hand they are very resistant to pressure and shear forces. Furthermore, ceramics, when used as a raw material for endoprostheses, have very good Bjo compatibility. Furthermore, the joint counterpart is often also made of a hard ceramic. Here, the advantageous tribological property of the hard ceramic can be further enhanced by the self-pairing of ceramic on ceramic.

The osseointegrative and / or osseoinductive or osseoconductive regions are further preferably formed from a porous ceramic. Bone can grow very well into the pores of the porous ceramic, which enables good bony integration. The osseointegrative and / or osseoinductive or osseoconductive areas are preferably formed from a ceramic which has a porosity of approximately 10-70 vol.%, Preferably approximately 20-60 vol.%.

The porosity of the ceramic on the outer circumference is preferably approximately 80% by volume and decreases radially in the direction of the body.

The outer envelope of the force-absorbing areas preferably has essentially the shape of a hemisphere.

A pole area of the substantially hemispherical outer envelope of the force-receiving areas is preferably flattened. This ensures a better fit of the endoprosthesis part.

An equatorial region of the substantially hemispherical outer envelope of the force-absorbing regions is further preferably widened. As a result, a type of “clamping area” can preferably be formed, which enables the endoprosthesis part to fit more firmly in the bone bearing.

According to the invention, the use of the endoprosthesis part according to the invention is further provided as a cementless anchored acetabular cup for receiving a corresponding hip joint head.

Furthermore, according to the invention, a production method for endoprosthesis parts according to the invention is provided, which has the following

Steps include:

Providing a body with one piece

Force receiving areas;

Provision of areas with osseointegrative and / or osseoinductive or osseoconductive properties;

Connecting the body to the osseointegrative and / or osseoinductive or osseoconductive areas. In the manufacturing method according to the invention, the body and the osseointegrative and / or osseoinductive or osseoconductive areas are preferably connected in a sandwich construction, the body and the force-absorbing areas integrally formed therewith being provided from a hard ceramic and the osseointegrative and / or osseoinductive or osseoconductive Porous ceramic areas are provided.

In the manufacturing method according to the invention, the body and the force-absorbing areas formed in one piece from a hard ceramic and the osseointegrative and / or osseoinductive or osseoconductive areas from a porous ceramic are preferably provided, and the porosity of the osseointegrative and / or osseoinductive or osseoconductive is more preferred Areas created by providing meltable particles in the green body of the ceramic and subsequent melting of the particles.

In a preferred embodiment of the manufacturing method according to the invention, the osseointegrative and / or osseoinductive or osseoconductive areas are sprayed onto the body in the spaces between the force absorption areas.

The osseointegrative and / or osseoinductive or osseoconductive areas are further preferably sprayed into the spaces between the force absorption areas by means of a titanium plasma spray process.

The osseointegrative and / or osseoinductive or osseoconductive areas (4) are preferably formed by means of hydroxyapatite or bone morphogenic proteins (BMP), which is applied in the spaces between the force absorption areas (2). Further objects, features and advantages of the present invention will become apparent from the exemplary description of the preferred embodiments with reference to the drawings, in which:

Figure 1 is a plan view of a first embodiment of the endoprosthesis part according to the invention.

Fig. 2 is a sectional view of the first embodiment along line A-A of Fig. 1;

3 shows a top view of a second embodiment of the endoprosthesis part according to the invention;

4 shows a top view of a third embodiment of the endoprosthesis part according to the invention;

5 shows a top view of a fourth embodiment of the endoprosthesis part according to the invention;

Fig. 6 is a sectional view of the fourth embodiment along line A-A of Fig. 5;

Fig. 7 is a sectional view of a fifth embodiment of the endoprosthesis part according to the invention along a line substantially corresponding to line A-A of Fig. 1;

FIG. 8 is a sectional view of a sixth embodiment of the endoprosthesis part according to the invention along a line which essentially corresponds to line A-A of FIG. 1.

In the embodiments presented below, endoprosthesis parts for the artificial cement-free replacement of an acetabular cup are described. However, the invention can Endoprosthesis part can also be used for other joints, such as finger, ankle or knee joints

Fig. 1 shows a plan view and Fig. 2 shows a sectional view of a first embodiment of the endoprosthesis part according to the invention along line A-A in Fig. 1. The endoprosthesis part is manufactured in a monoblock structure, i.e. the endoprosthesis part is of uniform design. It therefore has essentially no connection areas, which often represent a weak point of endoprosthesis parts in conventional endoprosthesis parts. Furthermore, the endoprosthesis part has an essentially hemispherical body 6, force-absorbing areas 2 formed on the outer circumference of the body 6 and a multiplicity of osseointegrative and / or osseoinductive or osseoconductive areas (bone formation areas) 4.

The body 6 essentially has the shape of a hollow hemisphere in order to reproduce the shape of an acetabular cup as advantageously as possible. However, a shape deviating from this is conceivable as long as appropriate contact with a joint counterpart is ensured. The body 6 can preferably be conical or frustoconical or parabolic. The inner concavity 8 is designed to receive a joint counterpart of a hip joint and to interact with it. The body 6 is preferably made of a hard ceramic, for example Al ₂ O ₃ or zirconium oxide ceramic, since hard ceramic has very good tribological properties. This is particularly advantageous, since a good interaction of the socket with the joint counterpart is achieved. In particular if the joint counterpart is also formed from a hard ceramic, the advantageous tribological properties of the hard ceramic can be reinforced by the self-pairing of ceramic on ceramic.

The force absorption areas 2 are formed in one piece or unitary with the body 6, preferably made of a hard ceramic. The ceramic of the body 6 and the force absorption areas 2 is preferably essentially completely closed, ie the pores have a diameter which is less than 5 μm is. The ceramic used preferably corresponds to the standard ISO 6474 2nd Edition, 1994. The force absorption areas 2 can very well absorb the forces which occur when the endoprosthesis part is inserted as described below. Preferably, at least three force-absorbing areas 2 are arranged on the circumference of the body 6 in a substantially uniform manner, which ensures a stable support of the endoprosthesis part.

The endoprosthesis part is fixed cement-free in the bone bed. To do this, it must be press-fit or anchored using a thread described later (so-called screw socket). In the press-fit insertion, the receiving area for the endoprosthesis part in the bone bearing is made somewhat smaller than the endoprosthesis part to be inserted and subsequently the endoprosthesis part is hammered into the bone bearing. The bone bearing preferably has an approximately 1-2 mm smaller diameter than the endoprosthesis part and is more preferably elliptical or oval. The undersizing of the bone bed ensures good primary stability of the endoprosthesis part in the first weeks and months after insertion, before a bony connection with the bone formation areas 4 can be formed. During the press-fit insertion, great pressure and shear forces occur due to the impact in the bone bearing, which are essentially absorbed by the force-absorbing areas 2.

In the preferred embodiment of the endoprosthesis part shown in FIGS. 1 and 2, the force absorption areas 2 are formed in the arrangement described below. From a pole 14 to an equator or equatorial region 16 of the body 6, substantially strip-shaped force-absorbing regions 2 extend at regular intervals. Eight such strips are preferably provided. Furthermore, an essentially annular force receiving area 2 is formed around the equator 16 of the body 6 and an essentially circular force receiving area 2 is formed on or on the pole 14 of the body 6. The bone formation areas are in the spaces formed by the force absorption areas 2 4 trained. The space between the bone and the bone formation areas 4 can be bridged by bone formation.

As can be seen in FIG. 2, the force absorption areas 2 protrude in the radial direction with respect to the bone formation areas 4. The radius difference of the force absorption areas is preferably 2 and

Bone formation areas 4 approx. 0.3 - 1 mm. When the endoprosthesis part is inserted, the force absorption areas 2 come into contact with the prepared bone bearing first and can thus absorb the forces that occur and protect the sensitive bone formation areas 4 from damage or destruction.

Furthermore, the force absorption areas 2 ensure the primary stability of the endoprosthesis part, which is achieved by the press-fit insertion of the endoprosthesis part. Due to the undersizing of the bone bearing, large pressure forces act on the endoprosthesis part even after insertion. These are preferably essentially absorbed by the force absorption areas 2 provided.

The force absorption areas 2 can further serve to secure the rotation. When inserted, the force-absorbing areas 2 are pressed slightly into the bone bearing and twisting of the endoprosthesis part in the bone bearing can thus be substantially avoided.

The bone formation areas 4 enable bony ingrowth (so-called secondary stability) and thus good long-term stability of the endoprosthesis part. The bone formation areas 4 grow through the blood path and after about 2 - 8 months, trabeculae form, which enable long-term stability of the endoprosthesis part. The bone formation regions 4 are preferably formed from a porous ceramic, into which the bone can grow well. The ceramic used more preferably has a porosity of 20-60% by volume. Alternatively, a decrease in the porosity from outside to inside can be provided in the radial direction, with preference a porosity of 80 vol.% on the outer circumference and a decrease to almost 0 vol.% is provided in the interior of the endoprosthesis part. However, other materials that have good osseointegrative and / or osseoinductive or osseoconductive properties can also be used, such as titanium applied or applied using a titanium plasma spray, titanium melts, an applied or applied layer of hydroxyapatite or one or more bone morphogenic proteins (bone morphogenic proteins, BMP), and which, as described later, can be attached to the body 6 of the endoprosthesis part. Further materials are, for example, tricalcium phosphate, polylactic acid, polyglycolic acid, polycaprolactone and various photopolymers which contain bone-morphogenic proteins and a transforming growth factor β (TGF β). Further such materials with good osseointegrative and / or osseoinductive or osseoconductive properties and / or their application or attachment to or on the body 6 can be found in EP-A-0 285 826 and US-A-5 702 446.

3 shows the top view of a second embodiment of the endoprosthesis part according to the invention. In this embodiment, the force absorption areas 2 are designed in the form of rings which are concentric with the pole 14 of the endoprosthesis part. The bone formation areas 4 are in turn arranged between the force absorption areas 2.

4 shows the top view of a third embodiment of the endoprosthesis part according to the invention. In this embodiment, the force absorption areas 2 are designed in the form of circular areas which are preferably distributed substantially uniformly on the circumference of the endoprosthesis part. However, the force receiving areas 2 can also have other regular and / or irregular shapes, e.g. an elliptical shape.

As described above, the force absorption areas 2 also serve to secure the rotation of the endoprosthesis part. To this anti-rotation effect To reinforce, rotation-securing devices are provided on or at the force-absorbing areas 2 in a further embodiment. 5 and 6 show a top view and a section of a fourth embodiment of the endoprosthesis part according to the invention, in which 2 additional triangular profile strips 12 are formed on the strip-shaped force-receiving areas. These additional protrusions 12 can penetrate even further into the bone bed and thus prevent rotation of the endoprosthesis part even more effectively. The profile strips 12 can also have other cross sections, for example rectangular, trapezoidal or semicircular. Furthermore, the rotational securing property of the force-absorbing areas 2 can be reinforced by projections, for example knobs, of different shapes. In particular, it is not necessary for the rotationally secure devices 12 to extend over the entire length of the force-absorbing areas 2. Rather, rotation-securing devices 12 arranged only in regions are also possible.

In the above-described embodiments of the endoprosthesis part according to the invention, the outer envelope essentially has the shape of a hemisphere. It can preferably be provided, as shown in FIG. 7, that the pole 14 of the hemisphere is flattened by a few millimeters, essentially approximately 2-4% of the outside diameter. In this way, a better fit of the endoprosthesis part can be achieved. 7, so-called “clamping areas” can preferably be formed by widening the substantially hemispherical endoprosthesis part toward the equator 16 by a few millimeters. This ensures better primary stability of the endoprosthesis part by a clamping effect of the expanded areas 7, the equatorial region 16 is expanded continuously, and it is also conceivable to expand the equatorial region 16 in regions or steps.

8, a sixth preferred embodiment of the endoprosthesis part according to the invention is described, which is anchored in the prepared bone bearing with the aid of threads. Here are on the The outer circumference of the endoprosthesis part with the body 6 and / or the force-absorbing areas 2 is provided with one-piece threads or threaded areas 10. In the present embodiment, the threads 10 have an acute cross section. Threads with a rectangular, trapezoidal, round or sawtooth-shaped cross section would also be conceivable. In this embodiment, the bony bearing must be prepared with appropriate taps. After the bone has been prepared accordingly, the endoprosthesis part can be screwed into the bone bed and thus firmly anchored. In this embodiment, the threads 10, as positive and frictional elements, take over the primary anchoring of the endoprosthesis part in the bone bearing. As in the preferred embodiments described above, the force absorption areas 2, in this case together with the thread 10, serve to absorb the forces that occur in the first time after the endoprosthesis part is inserted and thus to protect the sensitive bone formation areas 4. An embodiment would also be conceivable which has self-tapping threads or thread areas.

The dimensions of the endoprosthesis part according to the invention correspond to the values customarily used. More specifically, the outer diameter of the endoprosthesis part is approximately 44 mm - 64 mm and the inner diameter corresponding to approximately 22 mm, 28 mm, 32 mm or 35 mm.

Preferred embodiments of production methods for the endoprosthesis part according to the invention are described below. As already mentioned, the endoprosthesis part according to the invention is provided in a monoblock structure, i.e. the endoprosthesis part is of uniform design. It therefore has essentially no connection areas, which often represent a weak point of endoprosthesis parts in conventional endoprosthesis parts.

In the first manufacturing method, the manufactured endoprosthesis part has a body 6 and force-absorbing areas 2 formed thereon in one piece a hard all-ceramic and bone formation areas 4 made of a porous ceramic. In this manufacturing process, the endoprosthesis part is formed as a whole, ie all areas are manufactured at the same time. Al ₂ O ₃ and / or zirconium oxide is preferably used as the raw material for the production of the endoprosthesis part. First, the prepared and prepared raw materials are brought into the desired shape. This can be done, for example, in a casting or powder compaction process. The green body thus shaped is then dried and fired. The solidified form is then treated. In order to form the areas of the porous ceramic in this production method, meltable and / or burnable particles are provided in the green compact of the ceramic. These particles are melted out and / or burned out during or during the firing of the ceramic and leave voids which form a porosity. This manufacturing method is particularly advantageous if a change in the porosity in the endoprosthesis part in the radial direction as described above is desired.

In the sandwich construction, the body 6 is formed in a first step with the force-absorbing areas 2 formed thereon in one piece. In a second step, the bone formation areas 4 are applied into the spaces between the force absorption areas 2 and connected accordingly, for example by hardening or sintering the ceramic. Here, the body with the force-absorbing regions 2 formed thereon in one piece preferably consists of a hard all-ceramic, such as, for example, an Al ₂ O ₃ ceramic or zirconium oxide ceramic. The bone formation areas 4 again preferably consist of a porous ceramic. The bone formation regions 4 can further preferably have titanium or a titanium alloy which is sprayed on by means of a titanium plasma spray. Furthermore, the bone formation areas 4 can be formed by applying hydroxylapatite or BMP.

Claims

Expectations

Endoprosthesis part for the joint replacement, which has a body (6), a multiplicity of force-absorbing areas (2) formed integrally with the body (6), which can absorb a force acting on the endoprosthesis part, in particular when inserting the endoprosthesis part into a bone, and osseointegrative and / or osseoinductive or osseoconductive areas (4) which enable the endoprosthesis part to grow in bony or which stimulate or promote bone growth.

Endoprosthesis part according to claim 1, wherein the body (6) with the force absorption areas (2) and the osseointegrative and / or osseoinductive or osseoconductive areas (4) are provided in a monoblock structure.

Endoprosthesis part according to claim 1 or 2, which has at least three force absorption areas (2).

Endoprosthesis part according to one of the preceding claims, wherein the force absorption areas (2) are distributed substantially over the circumference.

Endoprosthesis part according to one of the preceding claims, wherein the osseointegrative and / or osseoinductive or osseoconductive regions (4) are arranged between two adjacent force absorption regions (2).

Endoprosthesis part according to one of the preceding claims, wherein the force absorption areas (2) project over the osseointegrative and / or osseoinductive or osseoconductive areas (4). Endoprosthesis part according to claim 6, wherein the force absorption areas (2) project by approximately 0.3 mm to 1 mm compared to the osseointegrative and / or osseoinductive or osseoconductive areas (4).

Endoprosthesis part according to one of the preceding claims, wherein the force absorption areas (2) at least partially have a thread or thread areas (10) formed thereon.

Endoprosthesis part according to one of the preceding claims, wherein devices (12) for securing against rotation are provided on the force absorption areas (2).

Endoprosthesis part according to one of the preceding claims, wherein the body (6) has good tribological properties on a side facing a joint (8).

Endoprosthesis part according to one of the preceding claims, wherein the body (6) and the force-receiving areas (2) are formed from a hard ceramic.

Endoprosthesis part according to one of the preceding claims, wherein the osseointegrative and / or osseoinductive or osseoconductive regions (4) are formed from a porous ceramic.

Endoprosthesis part according to claim 12, wherein the porous ceramic has a porosity of approximately 10-70 vol.%, Preferably approximately 20-60 vol.%.

Endoprosthesis part according to claim 12, wherein the porosity of the ceramic on the outer circumference is approximately 80 vol.% And decreases in the direction of the body (6). Endoprosthesis part according to one of the preceding claims, wherein the outer envelope of the force-receiving areas (2) has essentially the shape of a hemisphere.

Endoprosthesis part according to claim 15, wherein a pole region (14) of the substantially hemispherical outer envelope of the force-absorbing regions (2) is flattened.

Endoprosthesis part according to claim 15 or 16, wherein an equatorial region (16) of the substantially hemispherical outer envelope of the force-absorbing regions (2) is widened.

Use of the endoprosthesis part according to one of claims 1 to 17 as a cementless anchored acetabular cup for receiving a corresponding hip joint head.

Manufacturing method for endoprosthesis parts according to one of claims 1 to 17, comprising the following steps:

Providing a body (6) with one piece

Force absorption areas (2);

Providing areas (4) with osseointegrative and / or osseoinductive or osseoconductive properties;

Connecting the body (6) to the osseointegrative and / or osseoinductive or osseoconductive areas (4).

Manufacturing method according to claim 19, wherein the body (6) and the force-receiving areas (2) integrally formed therewith are provided from a hard ceramic and the osseointegrative and / or osseoinductive or osseoconductive areas (4) are provided from a porous ceramic, in which Step of connecting the body (6) and the osseointegrative and / or osseoinductive or osseoconductive areas (4) are connected in a sandwich construction. Manufacturing method according to claim 19, wherein the body and the force receiving areas (2) formed in one piece therewith are provided from a hard ceramic and the osseointegrative and / or osseoinductive or osseoconductive areas (4) are provided from a porous ceramic, and the porosity of the osseointegrative and / or osseoinductive or osseoconductive areas (4) is produced by the step of providing meltable particles in a green body of the ceramic and subsequent melting and / or burning out of the particles.

Manufacturing method according to claim 19, wherein the osseointegrative and / or osseoinductive or osseoconductive areas (4) are sprayed onto the body (6) in the spaces between the force receiving areas (2).

Manufacturing method according to claim 22, wherein the osseointegrative and / or osseoinductive or osseoconductive areas (4) are sprayed into the spaces between the force receiving areas (2) by means of a titanium plasma spray process.

The manufacturing method according to claim 22, wherein the osseointegrative and / or osseoinductive or osseoconductive areas (4) are formed by means of hydroxyapatite or bone morphogenic proteins (BMP), which is applied in the spaces between the force absorption areas (2).