DE202011050057U1 - Surface profiled grid body - Google Patents

Abstract

Bone implant with a metallic, porous fine structure (12) formed by a three-dimensional framework of interconnected webs (14) which create interconnected cavities (18) such that the cavities (18) adjoining the surface of the bone implant (1) at least are partially and / or partially open-cell, characterized in that the fine structure (12) on the surface of the bone implant (1) form a number of surface elements (20) for at least regionally optimizing the friction properties, which in their entirety form a coarse structure of the bone implant ( 1) define.

Description

The present invention relates to a surface-profiled grating body, in particular in the form of a bone implant, for example an acetabulum augmentate, formed by a three-dimensional metallic framework of interconnected webs.

Bone implants of the genus of the invention are used in particular for filling bone defects or for bridging and / or connecting bone elements, such as, for example, two vertebral bones of a spinal column. As a rule, they have a metallic, open-celled (open-cell) structure on the implant surface, preferably constructed of interconnected webs, and more preferably a filling of bone substitute material for accelerating the bone-building process after implantation thereof. Depending on the intended use, they can, for example, take on a load-bearing function as a so-called augmentation component with their lattice or framework structure in order to create a larger-area contact, for example between an acetabular cup and the pelvic bone or between two vertebral bones, etc. of a patient. Also, the present invention grid body corresponds exactly to such a bone implant and also has the above-mentioned technical features.

For example, from the WO 2008/040409 A1 As a primary source of information, a generic bone implant by way of example is known in the form of an augmentation component, which has a high load capacity and allows optimal ingrowth of bone material. The known bone implant consists of a three-dimensional framework of interconnected webs which form interconnected small cavities or cells with a size in the range of 0.5 mm to 6 mm and large cavities in a range of 6 mm to 20 mm. Both the small and the large cavities are open-celled adjacent the implant surface, resulting in small and large cavities designed to receive bone or bone replacement material for accelerated implant grafting.

Due to the open-cell design of the implant on the surface thereof, a surface roughness dependent on the lattice structure (referred to below as a fine structure) arises, so that the implant also enters into a specific frictional connection (or micro-positive connection) with the adjacent bone immediately after implantation the free protruding ridges dig into the bone material.

As a secondary source of information is the EP 2 140 835 A1 from the concrete, an acetabulum augmentate is known. This forms a part-spherical solid whose outer side forms a bone-contacting surface and the inside of which is adapted to the shape of a primary implant, in this case an acetabular cup. The known augmentation has a number of cavities which are open-celled at least towards the outside to allow ingrowth of the implant into the adjacent bone material. Further, a longitudinally slotted passage opening is formed in the augment, which connects the outside and inside of the augment with each other and which serves to introduce a fixing screw.

The acetabulum can thus be inserted into the substantially concave inside of the augment and mounted together with the augmentation on the pelvic bone of the patient. For this purpose, between implant, d. H. Augmentat and pan and pelvic bone entered a bone cement and then screwed the implant by means of bolts. In this case, at least one bolt is guided through the acetabulum and at the same time through the longitudinally slotted passage opening in the augment, so that the relative position of both implant parts remains fixed.

As already mentioned, the basic problem of persistent adhesion to the bone exists in the known bone implants in general and in the case of augmentates in particular. On the one hand, immediately after the implantation at least temporary sufficient adhesion must be ensured in order to be able to load the implant equally without this changing its implantation position, on the other hand the implant should be built as quickly and intensively as possible in order to quickly reach its maximum load capacity. Conventional processing methods (eg, coating and / or ablation) are not suitable for increasing friction on an open-cell (open-pored) three-dimensional structure. On the contrary, the removal or coating even leads to impurities and congestion of the pores.

In view of this problem, the object of the present invention is to increase the short- and long-term load capacity of a bone implant or a grid body suitable for this purpose. A particular aim here is to ensure, in particular immediately after the implantation of the bone implant (grid body), at least for the intended average load, a sufficient connection with the treated bone. Another goal is not to make the provision of the bone implant (grid body) more expensive.

This object is achieved by means of a bone implant or grid body with the features of claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

Basically, the bone implant according to the invention (grid body) has a metallic and porous fine structure (grid), which is preferably formed by a three-dimensional framework of interconnected webs, which produce interconnected cavities of the same or different size. Those cavities which adjoin the surface of the implant (grid body) or are cut by the implant surface are at least partially and / or partially open-celled. In that regard, the structure of the bone implant according to the invention corresponds to that of the aforementioned prior art.

In addition, it is now provided to superimpose on the surface side of this defined fine structure a coarse structure which is suitable for changing or improving the frictional and / or positive locking property of the implant surface, ie. H. To optimize the force and / or form-locking ability of the implant surface in adaptation to the intended site / purpose and thus to increase the primary stability in the bone stock. In other words, the invention in principle consists in the targeted adjustment of surface properties of a product (bone implant) from an open-cell three-dimensional (lattice) structure by varying the parameters of the (lattice) structure itself and at the same time covering them with a macrostructure, which also is variably adjustable, preferably by selected cutting or cutting the (lattice fine) structure to achieve a regular or irregular (but not random) surface structuring.

Specifically, according to the invention, the fine structure (or lattice structure) forms on the surface of the implant a number of surface elements which in their entirety define this coarse structure of the bone implant. The friction and / or form-fitting property is therefore determined by the combination of fine and coarse structure on the surface of the implant.

The advantage of this embodiment is that the coarse structure is formed by the components (webs / lattice) of the fine structure, i. H. the fine structure continues in the coarse structure or in the surface elements. This simplifies and facilitates the manufacture of the implant and thus contributes to the reduction of the manufacturing costs. Furthermore, the fine structure preferably also forms on the surface of the surface elements defining the coarse structure, which causes a further increase in the friction and / or form-locking capability of the implant surface. Moreover, in certain cases, setting a defined structural stability creates an improved mechanical situation. Thus, the so-called "stress shielding" can be reduced because a transition between the elastic modulus of bone and implant can be created. This will be described in more detail below.

Another or additional aspect of the invention provides that the surface elements are projections and / or recesses with respect to a base surface of the implant (grid body). In this case, on the one hand, the effect already known from the prior art occurs, namely that the free webs of the fine structure projecting on the base surface of the implant as well as on the surfaces of the surface elements engage in the adjacent bone material and thus form a type of micro force / Form-effect. On the other hand, the surface elements formed directly as projections and / or the optionally strip-shaped protrusions of the coarse structure which indirectly form due to the recess-like surface elements press into the bone material, thereby achieving a kind of macro force / shape fit.

An advantageous development of this aspect relates to the particular configuration of the projections / recesses of the coarse structure, namely to the effect that the projections / recesses are adjustable or selectable or preset with regard to their shape, size, number and / or orientation with respect to the base surface thus to obtain a predetermined friction and / or positive locking property. It has been found that bone implants should either have homogeneous friction / form-locking properties in order to achieve uniform adhesion to the bone in all directions or else to have inhomogeneous friction / form-fitting properties, in order to be more easily displaceable in an implantation direction, for example predetermined load direction (different to the implantation direction), however, develop a high adhesive force. Thus, it is possible to coat the base surface completely or only in sections with the coarse structure, wherein this in turn may be designed differently depending on the implantation process and the type of load.

It is also advantageous if the surface elements are arranged regularly or irregularly but not accidentally at least on a surface section of the implant (lattice body). Ie. the surface elements are not arranged in random random orientation but in a mosaic pattern according to a specific distribution plan, which approximates a certain friction / form-fitting behavior.

Another or additional aspect of the invention provides that the projections / recesses are in terms of their shape, size, number and / or orientation with respect to the base surface such or selectable or preset to a predetermined modulus of elasticity gradient from the base surface to get to that imaginary plane which is defined by the extreme ends of the projections. Ie. In this case, it is not the increase of the frictional / form-locking capability or the coefficient of friction that is the goal of the surface elements, but it is advantageously intended that the modulus of elasticity of the implant in the region of the imaginary plane which forms the first contact plane with an adjacent bone material should, at least approximates the modulus of elasticity of this bone material. The friction / form-locking capability can also be increased at the same time. The decisive factor, however, is that the friction / positive locking properties of the implant are improved / optimized by approaching the deformation behavior of the implant, at least in bone near areas to be treated bone and thus a detachment from the bone is avoided under stress.

In this case, it may even be the case that the surface elements are not intended to penetrate the bone material, but support only the bone surface, thereby defining a gap between the base surface of the implant and the bone. This can then preferably be filled with a bone cement or bone or bone substitute material.

The approach of the modulus of elasticity in the region of the imaginary implant level as defined above can also be made such that a certain degree of penetration is permitted, but the surface elements deform at least at their free end portions. In this case, the additional effect of undercutting / hooking occurs, whereby detachment of the implant from the bone can be prevented even more reliably.

A further or additional aspect of the invention is directed to the specific shaping of the surface elements, namely that the projections / recesses may be frusto-conical / truncated, pyramidal / truncated pyramidal, as well as beveled or point / needle-shaped. But there may be other geometries such as cylinder or cube shapes for the forward / backward jumps. Finally, there is also the possibility of combining different element shapes on a single implant. It is crucial that a similar or the same fine structure is retained even in the surface elements which form the coarse structure holistically.

According to another or additional aspect of the invention, the framework material which forms the surface elements is different from the rest of the framework material of the implant or at least has a different material property in this respect. In this case, the material choice for the surface elements may be used or, in addition to the particular shape, used to obtain certain frictional properties. One possibility is to use a special rigid material in the surface elements (in relation to the rest of the lattice body) which causes the bone to penetrate and / or to use a material in the surface elements whose flexibility (unlike the other comparatively rigid lattice body) approximated to be treated bones to prevent detachment of the implant due to incompatible flexibility properties.

It is advantageous if the bone implant according to the invention (grid body) is produced from a sintered material by a rapid prototyping method.

Another aspect of the invention is directed to the provision of a hip joint implant comprising an acetabular cup and a separate bone implant according to any of the preceding aspects as an acetabular augmentate. This augment is tuned to the acetabulum in such a way that the coarse structure of the augment is formed exclusively on the side facing away from the hip joint convex side surface. In order for a plan concerns the acetabulum at the augmentation while optimizing Friktions- / Formschlusseigenschaft on a bone facing surface portion of the augment or a part thereof is achieved.

It is advantageous in this case if the concave side surface of the augmentate is open-pored through the fine structure (in accordance with the convex, bone-facing side surface), so that a predetermined frictional engagement is obtained between the acetabular cup and the augment.

An advantageous development of the hip joint implant provides that the augmentation has a further preferably longitudinally slotted passage opening for carrying out a common mounting screw, wherein the inner wall of the passage opening is closed. Through the wall of solid material, an internal stability of the augment is achieved, which prevents compression of the grid structure when tightening the common mounting screw.

Finally, provision can be made for a base area adjoining the concave inner side facing the acetabular cup to be closed or fully sheathed, wherein a number of through-mounting holes open in the base area, whose inner walls are likewise closed (fully sheathed). This embodiment also contributes to the stiffening of the augment.

The invention will be explained below with reference to a preferred embodiment with reference to the accompanying figures.

1 shows in a perspective view the convex outside of a bone implant in the form of an augment, preferably an acetabular augment, according to a preferred embodiment of the invention,

2 shows an enlarged view of the surface fine structure of the augment according to 1 .

3 shows a pattern or a grid element according to the invention, from which builds the fine structure of the augmentation according to the invention,

4 shows a first side view of the augmentation according to the 1 for the representation of mounting holes,

5 shows in a perspective view of the concave inside of the bone implant according to the 1 and

6 to 26 show by way of example different shapes for the fine / coarse structure according to the invention.

That in the 1 illustrated bone implant (grid body) 1 The present invention, in the exemplary form of an augmentate, operatively operable with a well-known acetabular cup (not shown) according to the invention, has substantially a part-spherical volume with a concave inner surface 2 and a convex outside 3 whose respective centers (not shown) are spaced from each other. This creates a flat surface 4 on one the concave and convex side 2 . 3 interconnecting end face, whereas on the opposite end face a substantially sharp transition edge 6 between the concave and convex side 2 . 3 is trained. In a middle section of the concave and convex sides 2 . 3 is a longitudinally slotted breakthrough or through hole (recess) 8th formed the concave side 2 with the convex side 3 essentially connects vertically. Finally, in the flat area 4 a number (preferably 2 to 3) of mounting through holes 10 introduced, which is substantially parallel or at an angle to the slotted passage opening 8th extend and in an edge portion of the convex side 3 to open.

The augmentation 1 with the outer shape described above is defined by a three-dimensional framework or a lattice structure 12 formed, consisting of interconnected webs 14 forming a repetitive grid pattern 16 as it is in particular in the 3 is shown.

As a result, the grid pattern has 16 a kind of diamond lattice structure that has a cavity 18 which is open in all directions. Become these patterns 16 Joined three-dimensionally, the above-mentioned lattice structure results 12 (hereinafter referred to as fine structure) consisting of a plurality of webs 14 and cavities 18 between the jetties 14 through each other.

Like from the 4 and 5 is particularly good to see is the augmentation 1 designed as a partially open-pored or open-celled object (volume). In other words, in the present embodiment, the fine structure is sufficient 12 to the concave and convex outside 2 . 3 such that the cavities adjacent thereto 18 in the present case, all are open-celled and the adjacent webs 14 protrude outward, as in the 2 is shown in magnification. It should be noted that, depending on the required strength and / or rigidity of the implant 1 the mentioned pages 2 . 3 also at least partially closed, that can be covered with a solid material jacket.

Due to the open-cell design according to the 2 results in a rough, as well as porous surface at least on the concave side 3 and preferably also on the convex side 2 of the implant 1 so that the implant 1 Immediately after its mounting in / on a bone to be treated comes into frictional contact with the bone surface, wherein the resulting frictional connection by the exposed on the surface / projecting webs 14 a slipping of the implant 1 to counteract. At the same time, the open-celledness of the cavities adjoining the surface creates 18 the possibility of a gradual implantation of the implant 1 with bone, this process by prior (at least partial) filling of the cavities 18 for example, with bone substitute material is accelerated.

From the 1 . 4 and 5 It can also be seen that not all pages or Outer surfaces of the implant according to the invention must be designed open-cell, but depending on the expected load situation with a solid material shell (ie closed) may be coated. Thus, in the present case, at least the flat surface 4 as well as the insides of said through holes 8th . 10 completely closed in the above sense, in order to be able to withstand the clamping forces caused by mounting screws (not shown) inserted into the implant 1 be exercised. The 5 shows the concave inside 2 of the implant 1 open-celled, in order to be able to enter into an improved frictional contact with the hip acetabular cup (not shown) attached thereto. It is quite possible, this page 2 executed closed to accommodate higher contact forces can.

In the 1 is the implant according to the invention 1 in perspective view as well as in the direction of its convex side 3 shown, which is intended as a bone contact side.

This page 3 has another (surface) structure, which is the fine structure described above 12 is superior. In the concrete are on the convex side 3 a number of surface elements 20 arranged in their entirety a (second) coarse structure of the implant 1 define. The surface elements 20 are presently designed as truncated pyramidal projections, which are checkerboard-like (defines the coarse structure in this case) on the convex side 3 Distribute evenly and from a base of the convex side 3 protrude radially. Every surface element 20 is from the three-dimensional framework 16 which also forms the fine structure of the implant volume and has an open-cell element surface. In other words, the fine structure is sufficient 12 of the implant 1 not only to the base of the convex side 3 but also (in this particular case unchanged) to the surfaces of the surface elements 20 ,

The in the 1 shown truncated pyramidal projections 20 In the present case, the task is to press into the adjoining bone material in order thereby to effect a type of (micro) positive connection, but in any case the frictional connection between the bone and the implant 1 to increase. The strength of this achievable form or frictional connection with the adjacent bone is consequently determined by the fine structure 12 , which is reflected at ground and element surface and (plus) the coarse structure created by the surface elements 20 is produced.

From the above description it follows that the surface elements 20 have a certain stiffness and a certain shape must be able to penetrate the bone to be treated. For this purpose, in particular the truncated pyramid shape shown is suitable, but also a variety of other shapes, such as needle, conical, cylindrical or cube shapes are conceivable. Also it is not necessary the surfels 20 As shown point to set in a checkerboard pattern, but they can also be formed as parallel or cross running closed webs with any cross-sectional shape. Different forms for the surface elements are described below with reference to 6 to 26 described by way of example. Furthermore, they may be irregular or only in sections on the convex side 3 however, intentionally (not randomly) distributed to certain friction characteristics of the implant 1 to obtain. So it is possible that the surface elements 20 a movement of the implant 1 but should allow easy movement along the bone in a particular direction (such as for ease of insertion of the implant during implantation) but block movement in a different direction. Also could be the shape of the surfels 20 cause a barb function (for example, a bent / salaried shape on the principle of a sawtooth), which allows sliding in one direction, but in the opposite direction prevents. Finally, there is also the possibility of the material property of the fine structure 12 within the surface element (s) 20 towards the material property of the fine structure 12 within the remaining implant volume to change to a certain rigidity of the elements 20 to obtain.

The abovementioned means for adjusting / optimizing the friction property of the implant 1 about the shape, number, distribution and material properties of the (above) surface elements 20 but can also be used in another way the friction property setting.

So far, essentially that variant was considered, according to which the surface elements 20 in the form of protrusions in the bone at least partially clawed, they may intentionally also deformed to act as a barb. This inevitably increases the friction between bone and implant. 1

But there is also the possibility of the friction property of the implant 1 thereby optimizing the implant 1 at least at its surface facing the bone, the bone properties is approximated. In other words, a bone undergoes a certain deformation under load. If now an implant fixed to the bone, its deformation property under load to the bone is different, the implant can gradually detach from the bone.

As a result, the friction properties of the implant 1 with regard to the bone to be treated, for example, the modulus of elasticity of the implant 1 be approximated at least in the relevant surface area of the modulus of elasticity of the bone. The surface elements according to the invention 20 provide a suitable means for this.

So the shape of each surface element (protrusion) 20 whose number and / or arrangement (distribution) are determined to be in their entirety at an imaginary bone-contacting plane passing through the free ends of the elements 20 defines an overall stiffness / flexibility that approximates the bone. It is advantageous if this stiffness increases continuously / stepwise in the area of the bone contact plane in the direction of the implant until the required maximum rigidity is reached in the area of the base area of the implant. This can be, for example, by the pyramidal or conical shape and / or by a particular material selection / distribution within the elements 20 be achieved. Last but not least, it is also possible while maintaining the fine structure 12 (or their grid pattern), the web thickness in the surface elements 20 to change.

Above it was stated that the surface of each surface element 20 open-celled, ie the fine structure 12 to the outside of each surface element 20 enough. But it is also possible that only selected surface elements 20 open-cell surfaces, whereas other elements 20 are closed. It is also possible, in particular in the case of blunt projections 20 the flanks of the surface elements 20 closed to increase their rigidity, but to keep the top open-celled.

In the present embodiment, in the 2 represented cavities 18 in the fine structure 12 unfilled. However, they may be at least partially filled with a bone substitute material. Each cell width is in this case between 2 mm and 3 mm, preferably 2.4 mm and the strut thickness is set to 0.5 mm to 1 mm, preferably 0.8 mm. Depending on the purpose and the type of load, however, these values may also deviate from the stated ranges.

As material for the implant 1 is a titanium alloy provided, preferably Ti6Al4V the laser sintering method ("selective laser melting") using a CAD model to the implant 1 is formed. However, other materials and production methods of known type may also be used.

Following are some forms for the above described surface elements 20 specified. In principle, it should be noted that the surface elements 20 have heretofore been represented as projections projecting from a base surface of the implant. But it is also possible to form the surface elements as recesses, which represent cavities starting from the base surface.

The figures explained below each show on the left image the basic representation of a surface element and the coarse structure produced thereby, the images of which are on the right show different perspective views and enlargements of a respective implant section with fine structure and overlapping coarse structure.

According to the 6 to 13 are the surface elements shown as strip-like projections with cross-sections in trapezoidal ( 6 ), Swallowtail ( 7 ), Rectangular ( 8th ), flattened gutters ( 9 ), Triangular ( 10 ) 11 ), T- ( 12 ) and tapered channel shape ( 12 ). As can be seen in the images on the right, the fine structures in all examples extend into the surface elements and form open-cell surfaces there.

According to the 14 to 17 and 23 to 25 the surface elements are shown as socket-like projections with angular truncated pyramid ( 14 ), inverted truncated pyramid ( 15 ), Cube ( 16 ), rounded truncated pyramid ( 17 ), Columns- ( 24 ) and truncated cone shape ( 25 ). According to the 18 to 22 On the other hand, the surface elements are represented as pocket-like cavities or recesses, especially in angular tubs. 18 ), inverted pyramidal ( 19 ), Cube ( 20 ), Rounded Pan ( 21 ) and cylindrical shape ( 22 ). Finally, the 26 one more to 3 alternative fine structure, although also consists of interconnected webs, but do not represent a diamond lattice structure but a simple, essentially cube-shaped cross lattice. This simple fine structure can also be superimposed with all of the aforementioned coarse structures according to the invention, wherein in the 26 by way of example only truncated pyramidal strips are shown as surface elements.

Disclosed is a bone implant 1 , preferably Augmentat with a metallic, porous fine structure 12 the through a three-dimensional framework of interconnected webs 14 is formed, which interconnected cavities 18 produce. The to the surface of the implant 1 adjacent cavities 18 are at least partially and / or partially open-celled, so that the fine structure 12 on the implant surface. The fine structure 12 on the surface of the implant 1 additionally forms a number of surface elements 20 for at least partially optimizing the frictional property, which as a whole has a coarse structure of the bone implant 1 define.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2008/040409 A1 [0003]
• EP 2140835 A1 [0005]

Claims (15)

Bone implant with a metallic, porous fine structure ( 12 ) formed by a three-dimensional framework of interconnected webs ( 14 ), the interconnected cavities ( 18 ) in such a way that they are brought to the surface of the bone implant ( 1 ) adjacent cavities ( 18 ) are at least partially and / or partially open-celled, characterized in that the fine structure ( 12 ) on the surface of the bone implant ( 1 ) a number of surface elements ( 20 ) for at least partially optimizing the frictional property, which in its entirety forms a coarse structure of the bone implant ( 1 ) define. Bone implant according to claim 1, characterized in that it is an augmentate and preferably an acetabulum augmentate. Bone implant according to claim 1 or 2, characterized in that the surface elements ( 20 ) Projections and / or recesses with respect to a base surface of the bone implant ( 1 ) are. Bone implant according to claim 3, characterized in that the projections and / or recesses ( 20 ) are adjustable or selectable in terms of their shape, size, number and / or orientation relative to the base surface to obtain a predetermined friction value. Bone implant according to claim 4, characterized in that the friction value to be obtained is the same or different in all surface directions. Bone implant according to one of claims 3 to 5, characterized in that the projections and / or recesses ( 20 ) are arranged regularly or irregularly but not accidentally at least on a surface portion of the bone implant. Bone implant according to one of claims 3 to 6, characterized in that the projections ( 20 ) are adjustable or selectable with respect to the base surface in terms of their shape, size, number and / or orientation in order to obtain a predetermined modulus of elasticity gradient from the base surface to the imaginary plane extending from the outermost ends of the projections ( 20 ) is defined. Bone implant according to claim 7, characterized in that the modulus of elasticity of the bone implant ( 1 ) in the region of the imaginary plane, which is to form the first contact plane with an adjacent bone material, the modulus of elasticity of this bone material is at least approximated. Bone implant according to one of claims 3 to 7, characterized in that the projections and / or recesses ( 20 ) sockel / bag, gutter / gutter or needle / pore-shaped. Bone implant according to one of the preceding claims, characterized in that the framework material comprising the surface elements ( 20 ), to the rest of the skeletal material of the bone implant ( 1 ) is different or at least has a different material property. Bone implant according to one of the preceding claims, characterized in that the surface elements ( 20 ) in particular in the form of projections and / or recesses on the fine structure ( 12 ) are cut open. Bone implant according to one of the preceding claims, characterized in that the frictional property is determined by the combination of fine and coarse structure on the surface of the bone implant. Hip joint implant consisting of an acetabular cup and a bone implant ( 1 ) according to any one of claims 1 to 12 as an acetabular augment, characterized in that the coarse structure of the augmentate ( 1 ) exclusively on the side facing away from the acetabulum convex side surface ( 3 ) is trained. Hip implant according to claim 13, characterized in that the augmentation ( 1 ) a longitudinally slotted passage opening ( 8th ) for carrying out a common mounting screw, wherein the inner wall of the passage opening ( 8th ) is completely closed. Hip joint implant according to one of claims 13 and 14, characterized in that a base surface ( 4 ) is completely closed, which at the the acetabulum facing concave inside ( 2 ), whereby in the base area ( 4 ) a number of through-mounting holes ( 10 ), whose inner walls are also completely closed.

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