Planar bone replacement material and method for producing a porous body

Planar alloplastic bone replacement material and methods comprise at least one plate for augmentation of bone defects, whereby the bone replacement material consists of a biocompatible plastic material, a biocompatible metal and/or a biocompatible metal alloy, whereby the at least one plate comprises a planar structure and comprises a plurality of pins extending outwards from the planar structure of the at least one plate, whereby the pins each comprise at least one connecting element, whereby the pins are deformable elastically and are arranged sufficiently close to each other such that pressing the surfaces of multiple plates onto each other causes the connecting elements of different plates to interlock with and/or snap into each other and the mutually interlocked and/or snapped-in plates form an open-pored body of mutually interlocked and/or snapped-in plates.

This application claims priority of German patent application DE 10 2015 107 599.7 filing date May 13, 2015, the entire contents of which German patent application are incorporated herein by reference.

The invention relates to an alloplastic bone replacement material. The invention also relates to a method for producing a porous body from an alloplastic bone replacement material.

Accordingly, the subject of the invention is an alloplastic bone replacement material intended for filling and stabilising bone cavities. Moreover, the invention proposes a method for producing a free-formed porous body.

Bone replacement materials have been known for a long time and are used extensively in clinical applications (J. M. Rueger: Knochenersatzmittel, Orthopäde 27 (1998) 72-79.). The bone replacement materials used thus far are generally stable in volume, but not stable in shape. One notable exception is a bone replacement material that is distributed by the name of “Trabecular Metal™” by Zimmer and is known, for example from WO 2013/074 909 A1. Said material has a porous structure made to imitate the structure of human cancellous bone (sponge tissue). Said material consists of tantalum and is commercial in defined shapes and sizes. The material cannot be changed in shape and size in a surgical theatre. It cannot be processed with conventional tools in a surgical theatre. Therefore, the individual anatomical situation of the patient can be taken into account only to a limited degree. The medical user is left to attempt to adapt the implant bed to the given geometry or to insert an approximately fitting implant and to close the existing gaps with allogenic bone material or other volume fillers.

Especially in the reconstruction of acetabular roof defects in the scope of septic revision surgeries of infected hip prostheses, it is extremely important to substitute and bridge the missing bone substance in mechanically stable manner such that so-called revision acetabulum cups can be implanted.

Accordingly, it is the object of the invention to overcome the disadvantages of the prior art. Specifically, a bone replacement material for augmentation is to be developed that is well-suited for filling and bridging bone defects and can be formed for said purpose. The bone replacement material is to form a shape-stable porous body once it is formed without any need for chemical curing reactions, such as, for example, radical polymerisations. The bone replacement material is to possess open porosity and is to be mechanically stable after the forming process. In this context, the porosity and the size of the pores shall be sufficient and appropriate such that human bone of a patient treated with the bone replacement material can grow into the pores of the bone replacement material. Another aim is to have the bone replacement material, in the formed state, be as load-bearing as possible. Moreover, the bone replacement material must be biocompatible such that it can be inserted into the body of a patient.

The objects of the invention are met by a planar alloplastic bone replacement material comprising at least one plate, preferably comprising multiple plates, for augmentation of bone defects, whereby the bone replacement material consists of a biocompatible plastic material, a biocompatible metal and/or a biocompatible metal alloy, whereby the at least one plate comprises a planar structure and comprises a plurality of pins extending outwards from the planar structure of the at least one plate, whereby the pins each comprise at least one connecting element, whereby the pins are deformable elastically and are arranged sufficiently close to each other such that pressing the surfaces of multiple plates onto each other causes the connecting elements of different plates to interlock with and/or snap into each other and the plates that are interlocked with and/or snapped into each other form an open-pored body of plates that are interlocked with and/or snapped into each other.

According to the invention, biocompatible metals or biocompatible metal alloys are preferred for producing the plates of the bone replacement material.

Interlocking means that projections of the connecting elements of the pins of the plates engage projections, gripping surfaces or undercuts of connecting elements on pins of neighbouring plates such that the pins then are still mobile with respect to each other by pressing the plates further together, but can no longer be readily separated from each other. Snapping-in means that the connecting elements of the pins of the plates appropriately engage connecting elements of pins of neighbouring plates such that the plates can no longer be separated from each other, but can also not be moved towards each other any longer by pressing the plates further together. Accordingly, the connecting elements can be provided by means of hooks, grooves, undercuts, snap-in means and/or opposite snap-in means and/or by hooks, grooves, undercuts and/or snap-in elements.

According to the invention, the at least one plate and the three-dimensional body formed by multiple plates are preferably osteoconductive.

Theoretically, a single plate, for example one that can be folded once or multiple times to produce the desired three-dimensional body, can be sufficient. However, according to the invention, the bone replacement material comprises multiple plates that can be joined. Particularly preferably, the bone replacement material comprises multiple plates of different shapes that can be joined. The selection of the shape of the plates in this context is governed by the treatment scenario.

The term, “planar”, shall be understood to mean planar bodies and bodies derived from planar bodies that are each formed from one closed or, preferably, one perforated, plate-like base body. Perforated planar structures are preferred in this context because bone tissue can grow into the surface through said perforations and/or the pores formed by the perforation. It is particularly advantageous and preferred according to the invention to have one perforation and/or one pore arranged in the plate next to each pin. In this case, the interlocking and/or the snapping-in of multiple plates, i.e. of multiple planar augmentation materials, leads to the formation of an open porous body that is osteoconductive if the material is selected properly, such as, for example, tantalum.

According to the invention, the plates of the bone replacement material contacting each other form a mechanically stable composite upon exposure to a pressure.

The invention can provide the connecting elements of bone replacement materials according to the invention to be mushrooms, hooks, undercuts and/or snap-in elements, preferably mushrooms, hooks, undercuts, snap-in means and/or opposite snap-in means.

Said connecting elements are particularly well-suited for snapping into and/or interlocking with each other. Textile connecting elements, such as hook and loop fasteners with easily deformable fibers, however, are not suitable according to the invention, since no dimensionally stable and pressure-resistant bodies can be built up by them.

The invention can also provide the distance between the connecting elements and the planar structure of the at least one plate to be between 0.3 mm and 2 mm, preferably to be between 0.5 mm and 1 mm.

This can ensure that the pores remaining free between the interlocked or snapped-in connecting elements possess a sufficient diameter for an open-pored structure. As a result, the three-dimensional body made of bone replacement material thus produced is osteoconductive.

Moreover, the invention can provide the pins of the at least one plate to extend perpendicular or at an angle between 60° and 90°, preferably at an angle between 80° and 90°, out of the planar structure of the at least one plate.

As a result, the plates are particularly easy to connect to each other later on. Moreover, the load bearing capacity of the bone replacement material is thus made to be uniform.

The invention also proposes the connecting elements to be provided at the jacket surface of the pins.

As a result, a stable connection of the pins, and thus of the plates, to each other can be attained.

Preferred bone replacement materials can be provided appropriately such that plates pressed into each other interlock and/or snap-in irreversibly.

This ensures that no particles of the fully formed bone replacement material detach from the body thus formed. This prevents irritation of the treated body at the site of treatment.

A refinement of the present invention proposes the thickness of the at least one plate without projecting pins to be at most 1.5 mm, preferably the thickness to be between 0.25 mm and 1.5 mm, particularly preferably the thickness to be between 0.5 mm and 1 mm.

The thickness of the at least one plate is the dimension of the plate without the pins that are arranged perpendicular to the planar structure of the plate. As a result, the plates can be bent and/or deformed sufficiently such that they can be adapted to the treatment scenario.

Moreover, the invention can provide the at least one plate to be produced with a generative 3D printing method.

As a result, the plates, and thus the bone replacement material, can be produced inexpensively.

According to a preferred embodiment, the invention can provide at least one of the at least one connecting elements per pin to have a truncated cone shape, whereby the longitudinal axes of the pins form the longitudinal axes of the cones and whereby the jacket of the cones faces toward the outer side that faces away from the planar structure of the at least one plate.

As a result, the at least one plate can be connected in particularly stable manner by means of the connecting elements shaped as truncated cones. Moreover, said shaping prevents surrounding soft tissue and bone tissue from being injured after the implantation of the bone replacement material.

Moreover, the invention can provide at least one of the at least one connecting elements per pin in the form of a hook and/or as a mushroom head.

The hooks and/or the mushroom heads provide for stable and non-detachable connection of the plates to each other. If the connecting elements are mushroom head-shaped, they can possess, for example, a collar at the mushroom head edge provided in the direction of the planar structure such that hook-shaped connecting elements of other plates can engage this thus generated undercut, whereby an irreversible, non-detachable interlocked or snapped-in connection between the plates is produced. It is also feasible, and preferred according to the invention, that at least one plate contains various connecting elements or various pins with different connecting elements. Accordingly, a plate can simultaneously possess hooks and mushroom heads as connecting elements, both on the same pin and on different pins.

In a preferred embodiment, the connecting elements are provided as mushroom heads. In a particularly preferred embodiment, the mushroom heads are shaped appropriately such that the mushroom heads comprise a conical undercut on the side facing the surface of the at least one plate. As a result, hook-shaped snap-in elements can be interlocked irreversibly and non-detachably with said mushroom heads. If the shapes of the undercuts and of the mushroom heads match properly, further propulsion of the mushroom heads can be prevented such that the mushroom heads snap into the undercuts.

Particularly preferred bone replacement materials can be provided appropriately such that the pins contain a circumferential groove as additional connecting element between the planar structure of one plate and at least one of the at least one connecting elements, whereby connecting elements of other plates can interlock with or snap into said groove, preferably snap-in appropriately such that no further motion of the connecting elements along the pins is possible.

This also facilitates particularly stable connection of plates to each other. Moreover, it is advantageous in this context that this attains defined and unoccupied hollow spaces as open pores after snap-in connection of the plates in the body thus formed from the bone replacement material. Namely, further closure of the open-pored structure by further propulsion of the pins between the pins of an appended plate is prevented and the pores are thus kept open.

A refinement of the present invention proposes at least two connecting elements to be arranged in succession on the jacket surface of the pins, particularly preferably at least three connecting elements to be arranged in succession on the jacket surface of the pins.

As a result, plates can be interlocked and/or snapped-in at different distances from each other. This attains higher flexibility during the forming of the bone replacement material.

The invention can also provide the at least one plate to have the shape of a square, rectangle, trapezoid, parallelepiped and/or polygon.

By means of these shapes, the bodies made of the bone replacement material can be adapted particularly well to the bones to be filled and/or to be treated.

Moreover, the invention can provide the planar structure of the at least one plate to contain through-going pores, whereby the pores are rounded, in particular the pores comprise no sharp-edged contours, whereby the pores in the planar structure of the plate preferably have a free cross-section between 0.25 mm and 1 mm, particularly preferably between 0.3 mm and 0.9 mm.

This ensures that the pores extend in all directions into the three-dimensional body thus formed so that the bone growth can proceed specifically into the planar structure of the at least one plate.

Moreover, the invention can provide the planar structure of the at least one plate to contain through-going pores, whereby the depth of the pores perpendicular to the planar structure of the at least one plate is at least 0.25 mm, preferably at least 0.4 mm.

This can ensure that the pores are enveloped by the bone both stably and uniformly. The plates thus replicate a spongy tissue that corresponds to a normal bone structure (cancellous bone) and can osseointegrate well with a normal bone structure.

Moreover, the invention can provide the at least one plate to be made from biocompatible plastic material, stainless steel, titanium, a titanium alloy, tantalum, a tantalum alloy or composites of said materials.

Said materials are particularly well-suited for medical purposes and can be used to attain the suitable elastic properties of the pins. It is preferred, according to the invention, to produce plates consisting of metal or metal alloys by selective laser sintering or by melting with electron beams, preferably by a 3D printing method.

The biocompatible plastic material can be biodegradable. Polylactides, polyglycolides, polycaprolactones and polyester formed from different α-hydroxy carboxylic acids can be used for this purpose. Conceivable non-biodegradable plastic materials include polyamides, polyimides, polyetherketone, and polysulfone. Plates made of these non-biodegradable and biodegradable plastic materials can be produced by selective laser sintering

According to a refinement, the present invention can provide neighbouring pins that are arranged on the same side of a first plate of the at least one plate to be situated at an appropriate distance from each other such that the pins of the first plate, after elastic deformation due to interlocking with and/or snapping into a connecting element of a second plate of the at least one plate, enable at least two interlocks and/or snap-in connections to at least two further connecting elements of the second plate, preferably enable at least three interlocks and/or snap-in connections to three further connecting elements of the second plate.

Multiple interlocking and/or snap-in connection of the plates allows a particularly stable body to be formed from the bone replacement material.

Preferably, the invention can further provide the plate or at least one of the plates to comprise pins just on one side and to be attachable in planar manner to a bone on the other side, whereby, preferably, sharp tips are provided for this purpose that can be pushed into the bone or eyelets or boreholes are provided in the planar structure of the at least one plate by means of which the at least one plate can be screwed to a bone or attached by other means.

A plate of this type can be used for direct planar attachment to the bone. Eyelets or bore holes allow the bone replacement material and/or the plate to be screwed to the bone tissue and allow any number of further plates of the bone replacement material to be applied onto said plate and to subsequently be interlocked and/or snapped-in. By this means, complex three-dimensional structures of the type that occurs, for example, upon manifestation of acetabular roof defects, can be filled in load-bearing manner. Acetabulum cups can also be anchored on said structures, either cement-free or with bone cement.

Sharp tips can be provided for attachment to the bone surface even if both sides of the at least one plate comprise pins, in which case the tips should project beyond the pins with the connecting elements.

In embodiments having sharp tips, the planar bone replacement material can be anchored by punching the sharp tips into the bone tissue. Building on this substrate, any layers and/or plates of bone replacement material can be applied and interlocked.

The invention can just as well provide the at least one plate or at least one of the at least one plates to comprise pins on both sides.

Plates of this type allow for a layer-by-layer design of the three-dimensional body made of bone replacement material.

Moreover, the invention proposes the at least one plate to be mixed with inorganic or organic particulate bone replacement material and/or autologous or, also, allogenic cancellous bone.

This allows the bone healing and the connection of the bone replacement material to the bone to be accelerated.

Preferably, the invention can just as well provide the at least one plate to be coated with one or more pharmaceutical agents from the groups of antibiotics, bisphosphonates, steroids, non-steroidal anti-inflammatory drugs, growth factors, and cytostatic agents.

As a result, the bone replacement material has a pharmacological effect that contributes to the healing of the patient treated with the bone replacement material. Preferred agents from the group of antibiotics are, in particular, gentamicin, tobramycin, amikacin, vancomycin, teicoplanin, clindamycin, and daptomycin.

According to a further embodiment, the invention can provide the at least one plate or at least one of them as a semi-spherical cup or domed surface or as an arc or as a trough.

By this means, the plates can already be adapted to specific treatment scenarios and thus are particularly well-suited for forming domed structures.

Moreover, the invention proposes the pores of the open-pored body formed from multiple plates to be interconnecting and osteoconductive, whereby the pores preferably have a free cross-section between 0.1 mm and 1 mm, particularly preferably between 0.25 mm and 0.9 mm.

This ensures that the bone can grow well into the pores of the body formed from the bone replacement material.

The invention can just as well provide that the at least one plate can be plastically or elastically deformed in the planar structure.

As a result, the at least one plate can be adapted particularly easily to various treatment scenarios.

A refinement of the present invention proposes the pins having connecting elements to be arranged in rows of three or more pins each and a strip of unoccupied surface of the at least one plate to remain between these three or more rows each or to provide a grouped or nested arrangement of pins having connecting elements.

By this means, space is afforded for the deformation of the pins having the connecting elements upon the interlocking and/or snap-in connection.

According to a preferred refinement, the present invention can provide the bone replacement material to comprise at least one particle aside from the at least one plate, whereby the at least one particle comprises a core and at least six pins extending from the core, whereby the pins each comprise at least one connecting element that is designed in analogous manner to the connecting elements of the at least one plates such that the at least one plate and the at least one particle interlock with and/or snap into each other by pressing the connecting elements of the at least one plate and of the at least one particle onto each other, and whereby the plate(s) and particle(s) that are interlocked with and/or snapped into each other form an open-pored body of plate(s) and particle(s) that are interlocked with and/or snapped into each other.

As a result, an even more versatile bone replacement material is attained that can be free-formed and used to bridge gaps and cavities.

The objects underlying the present invention are also met by a method for forming a body made of a planar alloplastic bone replacement material according to the invention comprising multiple plates, in which multiple plates are pushed against each other, whereby the plates interlock with and/or snap into each other and form an open-pored body.

Said method can also provide for the pins with the connecting elements of at least two plates to be contacted to each other and for the pins with the connecting elements to be mutually interlocked and/or snapped-in by pressing the plates against each other.

The invention can just as well provide that at least one of the plates is being connected to a porous three-dimensional body of a second bone replacement material by snapping-in and/or interlocking the connecting elements with the pores of the second bone replacement material, and/or at least one of the plates are being connected to a particulate third bone replacement material comprising multiple particles, whereby the particles of the third bone replacement material comprise a plurality of pins that extend from a core of the particles and have connecting elements, whereby, preferably, the pins and the connecting elements of the particles of the third bone replacement material comprise the features of the pins and connecting elements of the at least one plate of the bone replacement material according to the invention.

The porous three-dimensional body of the second bone replacement material can, for example, be a Trabecular Metal™ made by Zimmer.

The underlying objects are also met through the use of the planar alloplastic bone replacement material according to the invention as implant material in trauma surgery, orthopaedics or veterinary medicine.

According to the invention, the plates of the bone replacement material contacting each other form a mechanically stable composite upon exposure to a pressure.

The invention is based on finding, surprisingly, that plates that snap-in and/or interlock mechanically can be used as alloplastic bone replacement material. In this context, the plates can be arranged layer-by-layer or just partially overlapping, whereby the thus formed porous three-dimensional body is firm and solid after formation of the desired three-dimensional structure without any need to have chemical curing reactions, such as, for example, radical polymerisations. Preferably, the plates are flexible to a limited extent and can thus be brought into the fitting shape and can be interlocked with each other and can thus be connected to each other by exerting a pressure. When the shaped plates snap into each other and/or interlock with each other, the plates mutually stabilise each other such that the resulting three-dimensional body made of the bone replacement material is firm and dimensionally stable. Connecting the plates by pushing them against each other from various directions at sufficient force ensures that a sufficient number of interlocks and snap-in connections is made such that the open-pored three-dimensional body thus generated is dimensionally stable and mechanically durable. Based on a suitable shape and size of the plates, a porous bone replacement material that is mechanically sufficiently stable for medical application is thus formed. The bone can grow into the pores of the bone replacement material connected by pressure and can thus become connected permanently to the bone replacement material.

It has been found, surprisingly, that the planar bone replacement material according to the invention can be placed, in the form of plates, layer-by-layer against surfaces of different shapes and can be cured into a porous, but homogeneous body through interlinking and/or snap-in connection of the individual layers of the planar augmentation material and/or bone replacement material by simple compression by hand or by means of a pestle. This is advantageous as compared to the previous “Trabecular Metal™” bone replacement material, whose shape and size cannot be freely determined by the medical user. It is thus feasible to fill or bridge bone defects of any shape with an in-situ curing and/or hardening augmentation material without needing any chemical reactions, such as for example radical polymerisations, for this purpose. The bone replacement material according to the invention can be cured easily by simply compressing plates whose surfaces are placed against each other. The planar augmentation material according to the invention makes a load-bearing augmentation feasible.

Mechanically interlocked systems following the design principles of hook and loop fasteners have been known for several decades. The principle of the hook and loop fastener was first described by de Mestral in CH 295 638 A. Said principle has been developed further and is put to use in a wide range of reversibly closing Velcro closures. Exemplary refinements are described in the publications, DE 1 610 318 A1, DE 1 625 396 A1, U.S. Pat. Nos. 5,077,870 A, and 4,290,174 A.

In the scope of the present invention, it has been evident, surprisingly, that said systems and/or said functional principles can be used for bone replacement materials and/or can be transferred to bone replacement materials. In this context, it is advantageous for the bone replacement materials that connections of this type do not close tightly, but rather gaps remain as an open-pored structure. Bone can grow into the interconnecting pores thus formed in the solid such that the pores allow a stable connection between the bone and the bone replacement material to be generated. For this purpose, one must make sure that the pores in the bone replacement material have a sufficient free cross-section. The pores are called osteoconductive, if the bone can grow into the pores and can thus become connected to the body formed from the bone replacement material.

An exemplary and, according to the invention, particularly preferred embodiment of the present invention is a planar augmentation material, in which three or more elastically deformable pins possessing at least one snap-in element each on a pin end are arranged on at least one surface of a planar structure formed from a biocompatible metal or metal alloy, and whereby the three or more pins are situated appropriately close to each other such that contact of the pins of at least two planar structures and exposure to pressure causes these to interlock with and/or snap into each other and thus form a composite of the planar augmentation materials.

In this context, the plates are designed appropriately such that pressing the plates together causes contacting plates to snap-in or interlock irreversibly and to form an open-pored body made of plates that are interlocked with or snapped into each other.

FIGS. 1 to 7show a first embodiment of the present invention, withFIG. 1showing a schematic perspective view of five plates of a bone replacement material according to the invention that are partially connected to each other to form an open-pored body and/or solid, andFIG. 2showing five schematic views of the two lower plates (base plates) according toFIG. 1, as A) perspective view, B) side view, C) top view of the top side, D) view of the bottom side, and E) cross-sectional view along the section A-A according toFIG. 2B). Moreover,FIG. 3shows three schematic views of the top three plates (build-up plates) according toFIG. 1, as A) perspective view, B) side view, and C) top view of the top side.FIG. 4shows a schematic perspective view of three plates of the bone replacement material according to the invention that are interlocked with each other to different depths for formation of an open-pored three-dimensional body according toFIGS. 1 to 3.

The plates consist of an elastic biocompatible plastic material or of stainless steel, titanium, a titanium alloy, tantalum, a tantalum alloy, but can also be fabricated from composites of said materials. The plates are manufactured by a CAM procedure (CAM—computer-aided manufacturing) and/or a 3D printing procedure, for example by selective laser melting SLM (selective laser melting). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates, such as, for example, Fused Layer Modeling/Manufacturing (FLM), Fused Deposition Modeling (FDM), Laminated Object Modelling (LOM) of plastic films, Layer Laminated Manufacturing (LLM) of plastic films, Electron Beam Melting (EBM) of plastic materials or metals, Multi Jet Modeling (MJM) of plastic materials, Selective Laser Sintering (SLS) of plastic materials or metals, Stereolithography (STL or SLA) of plastic materials, polishing or multi-axes milling procedures or Digital Light Processing (DLP) of photopolymerising liquid plastic materials.

The plates each comprise a plate-shaped planar structure1that bears the entire plates and connects them in itself. The planar structure1is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure1. A multitude of pins2extend away from the planar structure1of each plate, projecting perpendicularly away from the plane of the planar structure1. A multitude of through-going recesses3are arranged between the pins2in the planar structure1, which cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures1when the plates are connected to each other to form a solid.

FIGS. 1 to 7show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins2extend from the planar structure1only on one side of the planar structures1, and, secondly, build-up plates, in which the pins2extend from both sides of the planar structure1. The base plates are shown on the bottom inFIG. 1, inFIG. 2, on the bottom inFIG. 4, and on the bottom inFIG. 5. The build-up plates are shown on the top inFIG. 1, inFIG. 3, on the top inFIG. 4, on the top inFIG. 5, and inFIGS. 6 and 7. The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates, theoretically, can be omitted.

The pins2, otherwise being cylindrical, have mushrooms4as connecting elements4provided on the ends of the pins2opposite from the planar structures1. The mushrooms4are rounded towards the outside (away from the planar structure1) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. On the side oriented towards the planar structure1, the mushrooms4form a planar gripping surface6that is suitable for interlocking with other mushrooms4of engaging plates or with the recesses3of engaging plates.

In this context,FIG. 5shows a schematic side view of two plates of the bone replacement material according to the invention that are interlocked with each other just by means of the mushrooms4,FIG. 6shows a schematic side view of two plates of the bone replacement material according to the invention that are snapped into each other by means of the mushrooms4and by means of the recesses3of the planar structure1, andFIG. 7shows a schematic cross-sectional view of the two plates shown inFIG. 6that are snapped into each other by means of the mushrooms4and by means of the recesses3of the planar structure1.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other, such that the mushrooms4of the pins2of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure1. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the plates that are connected to each other remain in the regions of the pins2and the mushrooms4such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates as well. The plates have a cross-section and/or a thickness of approximately 5 mm such that the remaining pores have a free cross-section in the range of approximately 0.5 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can interlock with each other in a first stage by the mushrooms4elastically deforming the pins2of connected plates and by the mushrooms4limiting the motion of neighbouring plates away from the planar structure1due to the elastic restoring force of the pins2(seeFIG. 5). When the plates are pushed further into each other, the plates can snap into each other in a second stage by the mushrooms4being pushed through the recesses3of the planar structure1. In this context, the mushrooms4can get lodged in the recesses3which prevents the mushrooms4from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms4plastically deform the pins2or the recesses3or the mushrooms4to a small extent or, secondly, that the edges of the recesses3plastically deform the mushrooms4of neighbouring plates to a small extent and that the plates are thus snapped into each other. Moreover, two plates can be connected to each other through interlocking the plates in some areas by means of the mushrooms4and by snapping them into each other in other areas by means of the mushrooms4and recesses3. Preferably, the dimensions of the mushrooms4, the depth of the recesses3(and/or the thickness of the planar structure1), and the length of the pins2between the planar structure1and the mushrooms4are adapted to each other appropriately such that, upon interlocking of the plates, the surfaces of the mushrooms4facing away from the planar structure1touch against the surface of the planar structure1of neighbouring plates and, upon snapping the plates to each other, the surfaces of the mushrooms4facing away from the planar structure1touch against the gripping surface6of the mushrooms4of the neighbouring plate. As a result, the plates are not mobile with respect to each other without deformation when they are interlocked or when they are snapped-in.

In order to ensure that the gripping surfaces6or the opposite cap top sides of the mushrooms4do not close the recesses3completely and to thus ensure that the recesses3can be deformed more easily by the mushrooms4, the recesses6each comprise six slits that are distributed over the circumference of the recesses3. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

FIG. 8shows four schematic views of plates of a second alternative bone replacement material that are connected to each other, in A) a perspective view, B) a side view, C) a top view of the top side, and D) a cross-sectional view along the section C-C according toFIG. 8C).

The plates consist of stainless steel, titanium, a titanium alloy, tantalum, a tantalum alloy or can be fabricated from an elastic biocompatible plastic material or a composite of the metallic materials. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure11that bears the entire plates and connects them in itself. The planar structure11is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure11. A multitude of pins12extend away from the planar structure11of each plate, projecting perpendicularly away from the plane of the planar structure11. A multitude of through-going recesses13are arranged between the pins12in the planar structure11, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures11when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses13.

FIG. 8shows only one of the two types of plates, namely build-up plates, in which the pins12extend away from both sides of the planar structure11. Base plates may be provided just as well, in which a flat bottom side is provided and in which the pins12extend away from the planar structure11only on one side of the planar structure11. Said base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates shown can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins12, otherwise being cylindrical, have mushrooms14as connecting elements14provided on the ends of the pins12opposite from the planar structures11and in the middle between the ends of the pins12and the planar structures11. The mushrooms14are rounded towards the outside (away from the planar structure11) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. On the side oriented towards the planar structure11, the mushrooms14form a planar gripping surface16that is suitable for interlocking with other mushrooms14of engaging plates or with the recesses13of engaging plates.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIG. 8), such that the mushrooms14of the pins12of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure11. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins12and the mushrooms14such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 9 mm such that the remaining pores have a free cross-section in the range of approximately 0.5 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can interlock with each other in a first stage by the mushrooms14elastically deforming the pins12of connected plates and by the mushrooms14limiting the motion of neighbouring plates away from the planar structure11due to the elastic restoring force of the pins12. When the plates are pushed further into each other, the plates can snap into each other in a second stage by the outer mushrooms14being pushed through the recesses13of the planar structures11, as shown inFIG. 8. In this context, the outer mushrooms14can get lodged in the recesses13which prevent the mushrooms14from moving with respect to the neighbouring plate and thus snap the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms14plastically deform the pins12or the recesses13or the mushrooms14to a small extent or, secondly, that the edges of the recesses13plastically deform the mushrooms14of neighbouring plates to a small extent and that the plates are thus snapped into each other. A first interlocking proceeds already when the outer mushrooms14of neighbouring plates engage each other. Moreover, two plates can be connected to each other through interlocking the plates in some areas by means of the mushrooms14and by snapping them into each other in other areas by means of the mushrooms14and recesses13. Preferably, the dimensions of the mushrooms14, the depth of the recesses13(and/or the thickness of the planar structure11), and the length of the pins12between the planar structure11and the mushrooms14and between the inner and outer mushrooms14are adapted to each other appropriately such that, upon interlocking of the plates, the surfaces of the mushrooms14facing away from the planar structure11touch against the surface of the planar structure11of neighbouring plates and/or, upon connecting the plates, the surfaces of the mushrooms14facing away from the planar structure11touch against the gripping surface16of the mushrooms14of the neighbouring plate. As a result, the connected plates cannot move with respect to each other without deformation.

In order to ensure that the gripping surfaces16or the opposite cap top sides of the mushrooms14do not close the recesses13completely and to thus ensure that the recesses13can be deformed more easily by the mushrooms14, the recesses13each may comprise multiple slits (not shown) that are distributed over the circumference of the recesses13. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

Accordingly, the embodiment according toFIG. 8differs from the one according toFIGS. 1 to 7mainly in that the pins12comprise two mushrooms14that are arranged at a distance with respect to each other. Moreover, the recesses13comprise no additional slits.

FIG. 9shows four schematic views of plates of a third alternative bone replacement material that are connected to each other. In this context,FIG. 9A) shows a perspective view,FIG. 9B) shows a side view,FIG. 9C) shows a top view of the top side, andFIG. 9D) shows a cross-sectional view along the section B-B according toFIG. 9C).

The plates consist of titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from stainless steel, an elastic biocompatible plastic material or a composite of said materials. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure21that bears the entire plates and connects them in itself. The planar structure21is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure21. A multitude of pins22extend away from the planar structure21of each plate, projecting perpendicularly away from the plane of the planar structure21. A multitude of through-going recesses23are arranged between the pins22in the planar structure21, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures21when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses23.

FIG. 9shows only one of the two types of plates, namely build-up plates, in which the pins22extend away from both sides of the planar structure21. Base plates may be provided just as well, in which a flat bottom side is provided and in which the pins22extend away from the planar structure21only on one side of the planar structure21. Said base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates shown can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins22, otherwise being cylindrical, have mushrooms24as connecting elements24provided on the ends of the pins22opposite from the planar structures21. The mushrooms24are rounded towards the outside (away from the planar structure21) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. On the side oriented towards the planar structure21, the mushrooms24form a planar gripping surface26that is suitable for interlocking with or snap-in connection to other mushrooms24of engaging plates or with the recesses23of engaging plates.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIG. 9), such that the mushrooms24of the pins22of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure21. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins22and the mushrooms24such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 3 mm such that the remaining pores have a free cross-section in the range of approximately 0.3 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can interlock with each other in a first stage by the mushrooms24elastically deforming the pins22of connected plates and by the mushrooms24limiting the motion of neighbouring plates away from the planar structure21due to the elastic restoring force of the pins22. When the plates are pushed further into each other, the plates can interlock with or snap into each other in a second stage by the mushrooms24being pushed through the recesses23of the planar structures21, as shown inFIG. 9. In this context, the mushrooms24can get lodged in the recesses23which prevents the mushrooms24from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms24plastically deform the pins22or the recesses23or the mushrooms24to a small extent or, secondly, that the edges of the recesses23plastically deform the mushrooms24of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other through interlocking the plates in some areas by means of the mushrooms24and by snapping them into each other in other areas by means of the mushrooms24and recesses23. Preferably, the dimensions of the mushrooms24, the depth of the recesses23(and/or the thickness of the planar structure21), and the length of the pins22between the planar structure21and the mushrooms24are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms24facing away from the planar structure21touch against the surface of the planar structure21of neighbouring plates and, upon connection of the plates, the surfaces of the mushrooms24facing away from the planar structure21touch against the gripping surface26of the mushrooms24of the neighbouring plate. As a result, the connected plates cannot move with respect to each other without deformation.

In order to ensure that the gripping surfaces26or the opposite cap top sides of the mushrooms24do not close the recesses23completely and to thus ensure that the recesses23can be deformed more easily by the mushrooms24, the recesses23may each comprise multiple slits (not shown) that are distributed over the circumference of the recesses23. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

Accordingly, the embodiment according toFIG. 9differs from the one according toFIGS. 1to7mainly in that the pins22and the recesses23are situated at a somewhat larger distance with respect to each other. Moreover, the recesses23comprise no additional slits.

FIG. 10shows three schematic views of two plates of a fourth alternative bone replacement material that are connected to each other, A) perspective view, B) top view of the top side, C) cross-sectional view along the section A-A according toFIG. 10B), andFIGS. 11 to 13show further variants of the fourth alternative bone replacement material.

The plates consist of a biocompatible metal, such as stainless steel, titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from an elastic biocompatible plastic material or a composite of said materials. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure31that bears the entire plates and connects them in itself. The planar structure31is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure31. A multitude of pins32extend away from the planar structure31of each plate, projecting perpendicularly away from the plane of the planar structure31. A multitude of through-going recesses33are arranged between the pins32in the planar structure31, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures31when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses33.

FIGS. 10 to 13show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins32extend from the planar structure31only on one side of the planar structures31, and, secondly, build-up plates, in which the pins32extend from both sides of the planar structure31. The base plates are shown on the bottom inFIG. 10and/or below it, on the bottom inFIG. 11, on the top inFIG. 12, and on the bottom inFIG. 13A) and inFIGS. 13B) to D). The build-up plates are shown on the top inFIG. 10, on the top inFIG. 11, on the bottom inFIG. 12, and on the top inFIG. 13A). The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins32, otherwise being cylindrical, have mushrooms34as connecting elements34provided on the ends of the pins32opposite from the planar structures31. The mushrooms34are rounded towards the outside (away from the planar structure31) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. On the side oriented towards the planar structure31, the mushrooms34form a planar gripping surface36that is suitable for interlocking with or snap-in connection to other mushrooms34of engaging plates or with the recesses33of engaging plates.

Moreover, grooves37as connecting elements37are provided in the pins32adjacent to the gripping surfaces36, whereby the mushrooms34of neighbouring plates can engage and/or snap into the grooves37. For this purpose, the grooves37can be shaped differently from the grooves37shown, but in preferred manner according to the invention, as negative image of the shape of the curvature of the mushrooms34such that the mushrooms34fit well into the grooves37.

FIG. 11shows a schematic perspective view of two plates of the fourth bone replacement material according to the invention of the type according toFIG. 10that are connected by means of the connecting elements34,FIG. 12shows a schematic perspective view of two plates of the fourth bone replacement material according to the invention of the type ofFIGS. 10 and 11that are not connected to each other, andFIG. 13shows four schematic views of the fourth alternative bone replacement material in an embodiment having voids at the pins32, in A) a perspective view of two plates that are connected by means of the connecting elements, B) a side view of a base plate, C) a top view of the top side of the base plate according toFIGS. 13B), and D) a cross-sectional view along the section A-A according toFIG. 13C).

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIG. 10A) or11or13A)), such that the mushrooms34of the pins32of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure31. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins32, mushrooms34, and grooves37such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 6 mm such that the remaining pores have a free cross-section in the range of approximately 0.6 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can snap into each other in a first stage by the mushrooms34elastically deforming the pins32of connected plates and by the mushrooms34and/or by the edges of the mushrooms34being pushed into the grooves37by the elastic restoring force of the pins32and thus limiting the motion of neighbouring plates away from the planar structure31(seeFIGS. 10, 11, and 13A). When the plates are pushed further into each other, the plates can snap into each other in a second stage by the mushrooms34being pushed through the recesses33of the planar structure31(not shown). In this context, the mushrooms34can get lodged in the recesses33which prevents the mushrooms34from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms34plastically deform the pins32, the grooves37or the recesses33or the mushrooms34to a small extent or, secondly, that the edges of the recesses33plastically deform the mushrooms34of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other by snapping the plates into each other in some areas by means of the mushrooms34and the grooves37and by snapping them into each other in other areas by means of the mushrooms34and the recesses33. Preferably, the dimensions of the mushrooms34, the depth of the recesses33(and/or the thickness of the planar structure31), the shape of the grooves37, and the length of the pins32between the planar structure31and the mushrooms34are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms34facing away from the planar structure31touch against the surface of the planar structure31of neighbouring plates and/or, upon connection of the plates, the surfaces of the mushrooms34facing away from the planar structure31touch against the gripping surface36of the mushrooms34and preferably touch the grooves37of the pins32of the neighbouring plate along at least one line or particularly preferably in planar manner. As a result, the connected plates cannot move with respect to each other without deformation.

The grooves37also prevent the gripping surfaces36or the opposite cap top sides of the mushrooms34from completely covering the recesses33. For the recesses33to be more easily deformable by the mushrooms34, the recesses33can comprise multiple slits (not shown) that are distributed over the circumference of the recesses33. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

Accordingly, the fourth embodiment according toFIGS. 10 to 13differs from the one according toFIGS. 1 to 7mainly in that the pins32are thicker and comprise grooves37as additional connecting elements. Moreover, the recesses33comprise no additional slits.

FIG. 14shows a schematic perspective view of two plates of a fifth bone replacement material according to the invention that are connected to each other by means of the connecting elements.FIG. 15shows three schematic views of the two plates of the fifth alternative bone replacement material according toFIG. 14that are connected to each other, i.e.FIG. 15A) shows a top view of the top side,FIG. 15B) shows a side view, andFIG. 15C) shows a cross-sectional view along the section B-B according toFIG. 15A).

The plates consist of a biocompatible metal, in particular of stainless steel, titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from an elastic biocompatible plastic material or a composite of said materials. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure41that bears the entire plates and connects them in itself. The planar structure41is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure41. A multitude of pins42extend away from the planar structure41of each plate, projecting perpendicularly away from the plane of the planar structure41. A multitude of through-going recesses43are arranged between the pins42in the planar structure41, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures41when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses43.

FIGS. 14 and 15show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins42extend from the planar structure41only on one side of the planar structures41, and, secondly, build-up plates, in which the pins42extend from both sides of the planar structure41. The base plates are shown on the bottom inFIG. 14and/or below it, on the bottom inFIG. 15A) (in the image plane), on the bottom inFIG. 15B), and on the right inFIG. 15C). The build-up plates are shown inFIG. 14, on the top inFIG. 15A) (out of the image plane), on the top inFIG. 15B), and on the left inFIG. 15C). The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins42, otherwise being cylindrical, have mushrooms44or groups of four hooks45each provided as connecting elements44,45on the ends of the pins42opposite from the planar structures41. The mushrooms44are rounded towards the outside (away from the planar structure41) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. The hooks45are rounded towards the outside in like manner. On the side oriented towards the planar structure41, the mushrooms44form a planar gripping surface46that is suitable for interlocking with or snap-in connection to other mushrooms44and hooks45of engaging plates or with the recesses43of engaging plates. Accordingly, on the side oriented towards the planar structure41, the hooks45form undercuts that are suitable for interlocking with or snap-in connection to other mushrooms44and hooks45of engaging plates or with the recesses43of engaging plates.

Moreover, grooves47as connecting elements47are provided in the pins42adjacent to the gripping surfaces46and adjacent to the hooks45, whereby the mushrooms44and hooks45of neighbouring plates can engage and/or snap into the grooves47. For this purpose, the grooves47can be shaped differently from the grooves47shown, but in preferred manner according to the invention, as negative image of the shape of the curvature of the mushrooms44and/or hooks45such that the mushrooms44and hooks45fit well into the grooves47.

In the present fifth embodiment, hooks45are provided exclusively on the base plate as connecting elements45and mushrooms44are provided exclusively on the build-up plate as connecting elements44. This can be vice versa just as well and the hooks45and mushrooms44can also be present as mixed elements.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIG. 14 or 15), such that the mushrooms44and hooks45of the pins42of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure41. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins42, mushrooms44, hooks45, and grooves47such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 7 mm such that the remaining pores have a free cross-section in the range of approximately 0.7 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can snap into each other in a first stage by the mushrooms44and hooks45elastically deforming the pins42of connected plates and by the mushrooms44and hooks45and/or by the edges of the mushrooms44and tips of the hooks45being pushed into the grooves47by the elastic restoring force of the pins42and thus limiting the motion of neighbouring plates away from the planar structure41(seeFIGS. 14 and 15). When the plates are pushed further into each other, the plates can snap into each other in a second stage by the mushrooms44and hooks45being pushed through the recesses43of the planar structure41(not shown). In this context, the mushrooms44and hooks45can get lodged in the recesses43which prevents the mushrooms44and hooks45from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms44and/or the tips of the hooks45plastically deform the pins42, the grooves47or the recesses43or the mushrooms44to a small extent or, secondly, that the edges of the recesses43plastically deform the mushrooms44and/or hooks45of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other by snapping the plates into each other in some areas by means of the mushrooms44, hooks45and grooves47and by snapping them into each other in other areas by means of the mushrooms44and hooks45and the recesses43. Preferably, the dimensions of the mushrooms44, hooks45, the depth of the recesses43(and/or the thickness of the planar structure41), the shape of the grooves47, and the length of the pins42between the planar structure41and the mushrooms44or hooks45are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms44and hooks45facing away from the planar structure41touch against the surface of the planar structure41of neighbouring plates and/or, upon connection of the plates, the surfaces of the mushrooms44and hooks45facing away from the planar structure41touch against the gripping surface46of the mushrooms44and preferably touch the grooves47of the pins42of the neighbouring plate along at least one line or particularly preferably in planar manner. As a result, the connected plates cannot move with respect to each other without deformation.

The grooves47also prevent the gripping surfaces46or the opposite cap top sides of the mushrooms44or the hooks45from completely covering the recesses43. For the recesses43to be more easily deformable by the mushrooms44and hooks45, the recesses43can comprise multiple slits (not shown) that are distributed over the circumference of the recesses43. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

Accordingly, the fifth embodiment according toFIGS. 14 and 15differs from the one according toFIGS. 1 to 7mainly in that the pins42are thicker and comprise grooves47and in that hooks45are provided as connecting elements45. Moreover, the recesses43comprise no additional slits.

FIG. 16shows a schematic perspective view of two plates of a sixth bone replacement material according to the invention that are interlocked with each other, andFIG. 17shows a schematic perspective view of two plates of the sixth bone replacement material according to the invention according toFIG. 16that are not interlocked with each other.FIG. 18shows a schematic side view of plates of the sixth bone replacement material according to the invention according toFIG. 16that are interlocked with each other. And finally,FIG. 19shows a schematic perspective detailed view of two interlocked hooks (left), two non-interlocked hooks (right) of the sixth bone replacement material according to the invention according toFIGS. 16 to 18.

The plates consist of a biocompatible metal, in particular of stainless steel, titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from an elastic biocompatible plastic material. They can just as well be fabricated from a composite of said materials. The plates are produced through a CAM procedure and/or a 3D printing procedure. The rapid prototyping methods and/or computer-aided generative production methods mentioned with regard to other exemplary embodiments can be used to produce the plates.

The plates each comprise a plate-shaped planar structure51that bears the entire plates and connects them in itself. The planar structure51is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure51. A multitude of pins52extend away from the planar structure51of each plate, projecting perpendicularly away from the plane of the planar structure51. A multitude of through-going recesses53are arranged between the pins52in the planar structure51, which cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures51when the plates are connected to each other to form a solid.

FIGS. 16 to 18show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins52extend from the planar structure51only on one side of the planar structures51, and, secondly, build-up plates, in which the pins52extend from both sides of the planar structure51. The base plates are shown on the bottom inFIG. 16and/or below it, inFIG. 2and on the bottom inFIG. 18. The build-up plates are shown on the top inFIG. 16and on the top inFIGS. 17 and 18. The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins52, otherwise being cylindrical, have groups of four hooks55each provided as connecting elements55on the ends of the pins52opposite from the planar structures51. The hooks55are rounded towards the outside (away from the planar structure51) and form parts of spherical surfaces. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. On the side oriented towards the planar structure51, the hooks55form undercuts that are suitable for interlocking with or snap-in connection to other hooks55of engaging plates or with the recesses53of engaging plates. The pins52are thinner and/or shaped to have a smaller cross-section in the region adjacent to the hooks55and/or the undercuts of the hooks55. The hooks55of neighbouring plates can engage and/or snap into the thinner regions more easily.

The present sixth embodiment is provided exclusively with hooks55as connecting elements55. In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIG. 16 or 18), such that the hooks55of the pins52of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure51. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced. The interlocking is shown in detail inFIG. 19.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins52and the hooks55such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 5 mm such that the remaining pores have a free cross-section in the range of approximately 0.5 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can snap into each other in a first stage by the hooks55elastically deforming the pins52of connected plates and by the hooks55and/or by the tips of the hooks55being pushed into each other by the elastic restoring force of the pins52and thus limiting the motion of neighbouring plates away from the planar structure51(seeFIGS. 16, 18, and 19). When the plates are pushed further into each other, the plates can snap into each other in a second stage by the hooks55being pushed through the recesses53of the planar structure51(not shown). In this context, the hooks55can get lodged in the recesses53which prevents the hooks55from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the tips of the hooks55plastically deform the pins52or the recesses53to a small extent or, secondly, that the edges of the recesses53plastically deform the hooks55of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other by snapping the plates into each other in some areas by means of the hooks55and by snapping them into each other in other areas by means of the hooks55and the recesses53. Preferably, the dimensions of the hooks55, the depth of the recesses53(and/or the thickness of the planar structure51), and the length of the pins52between the planar structure51and the hooks55are adapted to each other appropriately such that, upon connection of the plates, the sides of the hooks55facing away from the planar structure51touch against the surface of the planar structure51of neighbouring plates and, upon connection of the plates, the sides of the hooks55facing away from the planar structure51touch against the undercuts of the hooks55. As a result, the connected plates cannot move with respect to each other without deformation.

The shape of the hooks55prevents them from covering the recesses53completely. For the recesses53to be more easily deformable by the hooks55, the recesses53can comprise multiple slits (not shown) that are distributed over the circumference of the recesses53.

Accordingly, the sixth embodiment according toFIGS. 16 to 19differs from the one according toFIGS. 1 to 7mainly in that regions of the pins52are thicker and mainly in that hooks55are provided as connecting elements55. Moreover, the recesses53comprise no additional slits.

FIG. 20shows a schematic perspective view of two plates of a seventh bone replacement material according to the invention that are not interlocked with each other, andFIG. 21shows three schematic views of two plates of the seventh alternative bone replacement material that are connected to each other, A) as a top view of the top side, B) as a side view, and C) as a cross-sectional view along the section B-B according toFIG. 21A).

The plates consist of a biocompatible metal, in particular of stainless steel, titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from an elastic biocompatible plastic material or a composite of said materials. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure61that bears the entire plates and connects them in itself. The planar structure61is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure61. A multitude of pins62extend away from the planar structure61of each plate, projecting perpendicularly away from the plane of the planar structure61. A multitude of through-going recesses63are arranged between the pins62in the planar structure61, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures61when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses63.

FIGS. 20 and 21show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins62extend from the planar structure61only on one side of the planar structures61, and, secondly, build-up plates, in which the pins62extend from both sides of the planar structure61. The base plates are shown on the bottom inFIG. 20, on the bottom inFIG. 21A) (in the image plane), on the bottom inFIG. 21B), and on the right inFIG. 21C). The build-up plates are shown on the top inFIG. 20, above the top inFIG. 21, i.e. inFIG. 21A) (out of the image plane), on the top inFIG. 21B), and on the left inFIG. 21C). The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins62, otherwise being cylindrical, have mushrooms64or groups of four hooks65each provided as connecting elements64,65on the ends of the pins62opposite from the planar structures61. The mushrooms64are rounded towards the outside (away from the planar structure61) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. The hooks65are rounded towards the outside in like manner. On the side oriented towards the planar structure61, the mushrooms64form a planar gripping surface66that is suitable for interlocking with or snap-in connection to other mushrooms64and hooks65of engaging plates or with the recesses63of engaging plates. Accordingly, on the side oriented towards the planar structure61, the hooks65form undercuts that are suitable for interlocking with or snap-in connection to other mushrooms64and hooks65of engaging plates or with the recesses63of engaging plates.

Moreover, grooves67as connecting elements67are provided in the pins62adjacent to the gripping surfaces66and adjacent to the hooks65, whereby the mushrooms64and hooks65of neighbouring plates can engage and/or snap into the grooves67. For this purpose, the grooves67can be shaped differently from the grooves67shown, but in preferred manner according to the invention, as negative image of the shape of the curvature of the mushrooms64and/or hooks65such that the mushrooms64and hooks65fit well into the grooves67.

The present seventh embodiment has mushrooms64and hooks65, mixed, provided on the plates as connecting elements64,65, whereby two of eleven connecting elements64,65are hooks65and the remaining elements are mushrooms64. This can be inverted just as well and the hooks65and mushrooms64can also be present at a different mixing ratio.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIG. 21), such that the mushrooms64and hooks65of the pins62of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure61. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins62, mushrooms64, hooks65, and grooves67such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 9 mm such that the remaining pores have a free cross-section in the range of approximately 0.9 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can snap into each other in a first stage by the mushrooms64and hooks65elastically deforming the pins62of connected plates and by the mushrooms64and hooks65and/or by the edges of the mushrooms64and tips of the hooks65being pushed into the grooves67by the elastic restoring force of the pins62and thus limiting the motion of neighbouring plates away from the planar structure61(seeFIG. 21). When the plates are pushed further into each other, the plates can snap into each other in a second stage by the mushrooms64and hooks65being pushed through the recesses63of the planar structure61(not shown). In this context, the mushrooms64and hooks65can get lodged in the recesses63which prevents the mushrooms64and hooks65from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms64and/or the tips of the hooks65plastically deform the pins62, the grooves67or the recesses63or the mushrooms64to a small extent or, secondly, that the edges of the recesses63plastically deform the mushrooms64and/or hooks65of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other by snapping the plates into each other in some areas by means of the mushrooms64, hooks65, and grooves67and by snapping them into each other in other areas by means of the mushrooms64and/or hooks65and the recesses63. Preferably, the dimensions of the mushrooms64, hooks65, the depth of the recesses63(and/or the thickness of the planar structure61), the shape of the grooves67, and the length of the pins62between the planar structure61and the mushrooms64or hooks65are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms64and hooks65facing away from the planar structure61touch against the surface of the planar structure61of neighbouring plates and/or, upon connection of the plates, the surfaces of the mushrooms64and hooks65facing away from the planar structure61touch against the gripping surface66of the mushrooms64and preferably touch the grooves67of the pins62of the neighbouring plate along at least one line or particularly preferably in planar manner. As a result, the connected plates cannot move with respect to each other without deformation.

The grooves67also prevent the gripping surfaces66or the opposite cap top sides of the mushrooms64or the hooks65from completely covering the recesses63. For the recesses63to be more easily deformable by the mushrooms64and hooks65, the recesses63can comprise multiple slits (not shown) that are distributed over the circumference of the recesses63. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

Accordingly, the fifth embodiment according toFIGS. 20 and 21differs from the one according toFIGS. 1 to 7mainly in that the pins62are thicker and comprise grooves67and in that hooks65are provided as connecting elements65. Moreover, the recesses63comprise no additional slits.

FIG. 22shows a schematic perspective view of two plates of an eighth bone replacement material according to the invention that are not interlocked with each other, andFIG. 23shows three schematic views of two plates of the eighth alternative bone replacement material that are connected to each other—FIG. 23A) shows a top view of the top side,FIG. 23B) shows a side view, andFIG. 23C) shows a cross-sectional view along the section C-C according toFIG. 23A).

FIG. 24shows a schematic perspective view of two plates of a modification of the eighth bone replacement material according to the invention that are not interlocked with each other, andFIG. 25shows three schematic views of two plates of the modification of the eighth alternative bone replacement material that are connected to each other—FIG. 25A) shows a top view of the top side,FIG. 25B) shows a side view, andFIG. 25C) shows a cross-sectional view along the section C-C according toFIG. 23A).

The plates consist of titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from another elastic biocompatible material. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure71that bears the entire plates and connects them in itself. The planar structure71is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure71. A multitude of pins72extend away from the planar structure71of each plate, projecting perpendicularly away from the plane of the planar structure71. A multitude of through-going recesses73are arranged between the pins72in the planar structure71, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures71when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses73.

FIGS. 22 to 25show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins72extend from the planar structure71only on one side of the planar structures71, and, secondly, build-up plates, in which the pins72extend from both sides of the planar structure71. The base plates are shown on the bottom inFIG. 22, on the bottom inFIG. 23A) (in the image plane), on the bottom inFIG. 23B), and on the right inFIG. 23C) as well as on the bottom inFIG. 24, on the bottom inFIG. 25A) (in the image plane), on the bottom inFIG. 25B), and on the right inFIG. 25C). The build-up plates are shown on the top inFIGS. 22 and 24and above the top inFIG. 23, i.e. on the top inFIG. 23A) (out of the image plane), on the top inFIG. 23B), and on the left inFIG. 23C) and/or on the top inFIG. 25A) (out of the image plane), on the top inFIG. 25B), and on the left inFIG. 25C). The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins72, otherwise being cylindrical, have mushrooms74or groups of four hooks75each provided as connecting elements74,75on the ends of the pins72opposite from the planar structures71. The mushrooms74are rounded towards the outside (away from the planar structure71) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. The hooks75are rounded towards the outside in like manner. On the side oriented towards the planar structure71, the mushrooms74form undercuts76that are suitable for interlocking with or snap-in connection to hooks75of engaging plates. Accordingly, on the side oriented towards the planar structure71, the hooks75form undercuts that are suitable for interlocking with or snap-in connection to other mushrooms74and hooks75of engaging plates or with the recesses73of engaging plates.

Moreover, grooves77as connecting elements77are provided in the pins72adjacent to the undercuts76and adjacent to the hooks75, whereby the mushrooms74and hooks75of neighbouring plates can engage and/or snap into the grooves77. For this purpose, the edges of the grooves77facing the planar structure71are shaped such as to be rounded such that the mushrooms74and hooks75fit and/or slide well in the grooves77.

In the present eighth embodiment, mushrooms74and hooks75are provided on the plates as mixed connecting elements74,75. In the variant according toFIGS. 22 and 23, two of eleven connecting elements74,75are hooks75and the remainder are mushrooms74. In the variant according toFIGS. 24 and 25, eight of eleven connecting elements74,75are hooks75and the remainder are mushrooms74. This can be inverted just as well and the hooks75and mushrooms74can also be present at a different mixing ratio.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIGS. 23 and 25), such that the mushrooms74and hooks75of the pins72of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure71. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins72, mushrooms74, hooks75, and grooves77such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness between 5 mm and 10 mm such that the remaining pores have a free cross-section in the range of approximately 0.5 mm and 1 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can snap into each other in a first stage by the mushrooms74and hooks75elastically deforming the pins72of connected plates and by the mushrooms74and hooks75and/or by the edges of the mushrooms74and tips of the hooks75being pushed into the grooves77by the elastic restoring force of the pins72and thus limiting the motion of neighbouring plates away from the planar structure71(seeFIGS. 23 and 25). When the plates are pushed further into each other, the plates can snap into each other in a second stage by the mushrooms74and hooks75being pushed through the recesses73of the planar structure71(not shown). In this context, the mushrooms74and hooks75can get lodged in the recesses73which prevents the mushrooms74and hooks75from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms74and/or the tips of the hooks75plastically deform the pins72, the grooves77or the recesses73or the mushrooms74to a small extent or, secondly, that the edges of the recesses73plastically deform the mushrooms74and/or hooks75of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other by snapping the plates into each other in some areas by means of the mushrooms74, hooks75, and grooves77and by snapping them into each other in other areas by means of the mushrooms74and/or hooks75and the recesses73. Preferably, the dimensions of the mushrooms74, hooks75, the depth of the recesses73(and/or the thickness of the planar structure71), the shape of the grooves77, and the length of the pins72between the planar structure71and the mushrooms74or hooks75are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms74and hooks75facing away from the planar structure71touch against the surface of the planar structure71of neighbouring plates and/or, upon connection of the plates, the surfaces of the mushrooms74and hooks75facing away from the planar structure71touch against the undercuts76of the mushrooms74and preferably touch the grooves77of the pins72of the neighbouring plate along at least one line. As a result, the connected plates cannot move with respect to each other without deformation.

The grooves77also prevent the gripping surfaces76or the opposite cap top sides of the mushrooms74or the hooks75from completely covering the recesses73. For the recesses73to be more easily deformable by the mushrooms74and hooks75, the recesses73can comprise multiple slits (not shown) that are distributed over the circumference of the recesses73. The width of the slits should be sufficient to allow them to have an osteoconductive effect.

Accordingly, the eighth embodiment according toFIGS. 22 to 25differs from the embodiment according toFIGS. 20 and 21in that the mushrooms74comprise undercuts76that can be engaged by the hooks75of adjacent plates.

FIG. 26shows a schematic perspective view of three and six pairwise mutually connected plates of the eighth alternative bone replacement material and of three particles of a bone replacement material, whereby the plates can be connected to the particles.

The particles are composed of a core that is arranged in the geometrical centre of the particles as well as twenty pins82that extend radially away from the core in various directions. Either mushrooms84or a group of four hooks85each are arranged as connecting elements84,85on the otherwise cylindrical pins82. The mushrooms84and hooks85correspond to the mushrooms74and hooks75of the plates and have similar dimensions. Accordingly, the mushrooms84and the hooks85are shaped to be spherically rounded towards the outside (away from the core). Other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. The mushrooms84have undercuts on the side oriented toward the core. Likewise, the hooks85comprise undercuts. The undercuts of the mushrooms84and the undercuts of the hooks85are suitable for interlocking with and/or snap-in connection to other mushrooms84and hooks85of engaging particles or for interlocking with and/or snap-in connection to the mushrooms74and hooks75of engaging plates.

Preferably, the pins72and connecting elements74,75of the plates are matched to the pins82and connecting elements84,85of the particles to allow uniform stability to be attained. The materials from which the particles can be made can be the same as the materials of the plates, and the same production procedures can be used.

The plates can be connected to the bone of a patient through fastening means (not shown) in the form of tips or screws. Subsequently, further plates of the bone replacement material according to the invention or the particles are fastened on the plate. In this context, the particles and the plates become appropriately connected to each other such that free gaps remain between the particles and plates that are connected to each other such that the reinforced three-dimensional body formed from the particles and plates is open-pored. The free cross-sections of the open-pored structure must still be sufficient such that bone material can form in and/or grow into the pores. The open-pored three-dimensional body formed from the plates and particles can therefore be called osteoconductive. To promote the osteoconductivity, the surface of the particles can just as well be coated with a bone growth-promoting substance. The three-dimensional body formed from the particles and plates is therefore well-suited as bone replacement material.

FIGS. 27 to 30show plates of a ninth alternative bone replacement material according to the invention that is particularly preferred according to the invention. In this context,FIG. 27shows a schematic perspective view of two plates snapped into each other,FIG. 28shows a schematic perspective view of two plates according toFIG. 27that are not snapped into each other,FIG. 29shows two schematic views of the plates according toFIG. 27that are snapped into each other, i.e. a top view of the top side (on the bottom inFIG. 29) and a side view (on the top inFIG. 29), andFIG. 30shows a schematic cross-sectional view of the section A-A according to the bottom ofFIG. 29of the plates according toFIGS. 27 and 29that are snapped into each other.

The plates consist of titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from another elastic biocompatible material. The plates are produced through a CAM procedure and/or a 3D printing procedure, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure91that bears the entire plates and connects them in itself. The planar structure91is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure91. A multitude of pins92extend away from the planar structure91of each plate, projecting perpendicularly away from the plane of the planar structure91. A multitude of through-going recesses93are arranged between the pins92in the planar structure91, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures91when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses93.

FIGS. 27 to 30show two different types of plates, namely, firstly, base plates that comprise a flat bottom side and in which the pins92extend from the planar structure91only on one side of the planar structures91, and, secondly, build-up plates, in which the pins92extend from both sides of the planar structure91. The base plates are shown on the bottom inFIG. 27and/or below it, inFIG. 28and on the bottom in the side view according toFIG. 29, below in the top view according toFIG. 29(in the image plane), and on the bottom left inFIG. 30. The build-up plates are shown above the top inFIG. 27, inFIG. 28and on the top in the side view according toFIG. 29, above in the top view according toFIG. 29(out of the image plane), and on the top right inFIG. 30. The base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins92, otherwise being cylindrical, have mushrooms94as connecting elements94provided on the ends of the pins92opposite from the planar structures91. The mushrooms94are rounded towards the outside (away from the planar structure91) and form spherical segments. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. On the side oriented towards the planar structure91, the mushrooms94form a planar gripping surface96that is suitable for interlocking with or snap-in connection to other mushrooms94of engaging plates or with the recesses93of engaging plates.

Moreover, grooves97as connecting elements97are provided in the pins96and/or the gripping surfaces96, whereby the mushrooms94of neighbouring plates can engage and/or snap into the grooves97. For this purpose, the edges of the grooves97facing the planar structure91are shaped such as to be rounded such that the mushrooms94fit and/or slide well in the grooves97. The shape of the grooves97corresponds to a negative image of the shape of the surface of the mushrooms94such that these can touch against a line in one of the grooves97. The mushrooms94thus form snap-in means94and the grooves97form the matching opposite snap-in means97. Further insertion of the plate is prevented by this structure.

The pins92with the mushrooms94are arranged in groups and/or islands of sixteen pins92and/or mushrooms94each. By this means, the pins92arranged on the edge of the groups and/or islands can be deformed outwards more easily when the mushrooms94of another plate are being pushed on. By this means, the plates can be connected to each other more easily since the elastic deformations of the pins92do not interfere with each other when the mushrooms94snap into the grooves97.

In the present ninth embodiment, only mushrooms94and grooves97are provided on the plates as connecting elements94,97. Alternatively or in addition, hooks (not shown) can be provided on the pins92as connecting elements.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other (i.e. unlike what is shown inFIGS. 27, 29, and 30), such that the mushrooms94of the pins92of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure91. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins92, mushrooms94, and grooves97such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness between 5 mm and 10 mm such that the remaining pores have a free cross-section in the range of approximately 0.5 mm and 1 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can interlock with each other by the mushrooms94elastically deforming the pins92of connected plates and by the mushrooms94and/or by the edges of the mushrooms94being pushed into the grooves97by the elastic restoring force of the pins92and thus limiting the motion of neighbouring plates away from the planar structure91(seeFIGS. 27, 29, and 30). Since the shape of the grooves97is made to match that of the mushrooms94further motion of the mushrooms94is blocked, specifically when a large number of mushrooms94is snapped into a large number of grooves97.

Preferably, the dimensions of the mushrooms94, the thickness of the planar structure91, the shape of the grooves97, and the length of the pins92between the planar structure91and the mushrooms94are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms94and hooks95facing away from the planar structure91touch against the surface of the grooves97of neighbouring plates and, upon connection of the plates, the gripping surfaces96of the mushrooms94touch against the gripping surfaces96of the mushrooms94of the neighbouring plate. As a result, the connected plates cannot move with respect to each other without the action of a large force.

The grooves97also prevent the gripping surfaces96or the opposite cap top sides of the mushrooms94from completely covering the recesses93. For the recesses93to be covered even less well by the mushrooms94, the recesses93can comprise multiple slits (not shown) that are distributed over the circumference of the recesses93.

Accordingly, the ninth embodiment according toFIGS. 27 to 30differs from the embodiment according toFIGS. 1 to 7mainly in that the mushrooms94comprise matching grooves97as additional connecting elements into which the mushrooms94of adjacent plates can snap, and in that the pins92are thicker. Moreover, the recesses93comprise no additional slits.

FIG. 31shows a schematic perspective view of multiple plates of a tenth and eleventh bone replacement material according to the invention which are partly interlocked by its connecting elements104,114.

FIGS. 31, 33 and 36show plates of a tenth bone replacement material according to the invention, which is especially preferred according to the present invention. In thatFIG. 33showing three schematic views of a plate of the tenth alternative bone replacement material, namely on bottom ofFIG. 33a top view of the top side, in the middle ofFIG. 33a side view and on top ofFIG. 33a cross-sectional view along the section B-B according toFIG. 33bottom.FIG. 36showing two schematic views of two plates of the tenth alternative bone replacement material that are connected to each other, namely on bottom ofFIG. 36a top view of the top side and on top ofFIG. 36a cross-sectional view along the section E-E according toFIG. 36bottom.

FIGS. 31, 34 and 37show plates of an eleventh bone replacement material according to the invention, which is especially preferred according to the present invention. In thatFIG. 34showing three schematic views of a plate of the eleventh alternative bone replacement material, namely on bottom ofFIG. 34a top view of the top side, in the middle ofFIG. 34a side view and on top ofFIG. 34a cross-sectional view along the section C-C according toFIG. 34bottom.FIG. 37showing two schematic views of two plates of the eleventh alternative bone replacement material that are connected to each other, namely on bottom ofFIG. 37a top view of the top side and on top ofFIG. 37a cross-sectional view along the section F-F according toFIG. 37bottom.

FIGS. 32 and 35show plates of a twelfth bone replacement material according to the invention, which is also especially preferred according to the present invention. In thatFIG. 32showing three schematic views of a plate of the twelfth alternative bone replacement material, namely on bottom ofFIG. 32a top view of the top side, in the middle ofFIG. 32a side view and on top ofFIG. 32a cross-sectional view along the section A-A according toFIG. 32bottom.FIG. 35showing two schematic views of two plates of the twelfth alternative bone replacement material that are connected to each other, namely on bottom ofFIG. 35top view of the top side and on top ofFIG. 35a cross-sectional view along the section D-D according toFIG. 35bottom.

The three embodiments ten, eleven and twelve are very much alike and therefore can be described together in the following.

The plates consist of titanium or a titanium alloy, tantalum or a tantalum alloy or can be fabricated from another elastic biocompatible material. The plates are produced through a CAM procedure or a 3D printing procedure respectively, for example through selective electron beam melting (EBM). Other rapid prototyping methods and/or computer-aided generative production methods can also be used for producing the plates.

The plates each comprise a plate-shaped planar structure101,111,121bearing the entire plates and connecting them in themselves. The planar structure101,111,121is flexible and can be deformed elastically such that surfaces other than planes can be formed with the planar structure101,111,121. A multitude of pins102,112,122extend away from the planar structure101,111,121of each plate, projecting perpendicularly away from the plane of the planar structure101,111,121. A multitude of through-going recesses103,113,123are arranged between the pins102,112,122in the planar structure101,111,121, which can cause the three-dimensional body to possess an open porosity in a direction perpendicular to the planar structures101,111,121when the plates are connected to each other to form a three-dimensional body and when the neighbouring plates do not touch and thus cover the recesses103,113,123.

InFIGS. 31 to 37two types of plates are shown for the tenth, eleventh and twelfth embodiment, namely firstly base plates, which provide a flat bottom side and in which the pins102,112,122extend away from the planar structure101,111,121only on one side of the planar structure101,111,121and secondly build-up plates, in which the pins102,112,122extend away from both sides of the planar structure101,111,121. The base plates being shown inFIG. 31bottom left and in all other Figures as the lower of both shown plates. Said base plates can be attached to the bone to be treated such that large surface areas touch against it. However, the build-up plates shown can also be attached to the bone to be treated, although with a lesser contact surface, such that the base plates can be omitted.

The pins102,112,122, otherwise being cylindrical, each have four mushrooms104,114,124as connecting elements104,114,124provided on above one another. The mushrooms104,114,124are rounded towards the outside (away from the planar structure101,111,121). The mushrooms104,124of the tenth embodiment (FIGS. 31, 33 and 35) and the twelves embodiment (FIGS. 32 and 35) form spherical segments on the tips of the pins102,122, while the mushrooms114of the eleventh embodiment being slightly spikier on the tips of the pins112. However, other types of rounding, such as, for example, ellipsoidal segments, are feasible just as well. The mushrooms104,114,124located beneath the mushrooms104,114,124on the tip of the pins102,112,122, which are therefore located in between the planar structure101,111,121and the mushrooms104,114,124which are located on the pins102,112,122on the side away from the planar structure101,111,121, having the shape of a truncated cone. On the side oriented towards the planar structure101,111,121, the mushrooms104,114,124form a planar gripping surface106,116,126that is suitable for interlocking with or snap-in connection to other mushrooms104,114,124of engaging plates or with the recesses103,113,123of engaging plates. The pins112and mushrooms114of the eleventh embodiment (FIGS. 31, 34 and 37) have a slightly smaller diameter than that of the tenth and twelfth embodiment, whereby the gripping surfaces116of the eleventh embodiment are configured somewhat deeper or with a larger area than the gripping surfaces106,126of the tenth and twelfth embodiments.

Moreover, grooves107,117,127as connecting elements107,117,127are provided in the pins102,112,122adjacent to the gripping surfaces106,116,126, whereby the mushrooms104,114,124of neighbouring plates can engage and/or snap into the grooves107,117,127. For this purpose, the grooves107,117,127are formed approximately as negative image of the shape of the curvature of the mushrooms104,114,124such that the mushrooms104,114,124match along a line to the grooves107,117,127. The mushrooms104,114,124thus form snap-in means104,114,124and the grooves107,117,127form the matching opposite snap-in means107,117,127. Further insertion of the plate is possible in the tenth, eleventh and twelfth embodiment, by pushing the pins102,112,122together with the mushrooms104,114,124into or respectively through the recesses103,113,123.

For the twelfth embodiment the pins122with the mushrooms124are arranged in groups and/or islands of forty-six pins122each. By this means, the pins122arranged on the edge of the groups and/or islands can be deformed outwards more easily when the mushrooms124of another plate are being pushed on. By this means, the plates can be connected to each other more easily since the elastic deformations of the pins122do not interfere with each other when the mushrooms124snap into the grooves127.

In order to form a bone replacement material according to the invention, the plates preferably are situated to touch against each other, without being interlocked with or snapped into each other, such that the mushrooms104,114,124of the pins102,112,122of neighbouring plates do not engage each other yet. Moreover, the plates can be present in a condition wetted by a liquid. The liquid preferably contains at least one pharmaceutically active substance suitable for controlling an infection or for stimulating bone growth. Alternatively or in addition, the plates can be coated with a pharmaceutically active substance of this type.

The bone replacement material can be formed by pushing the plates into each other by means of their surfaces. By this means, the plates interlock with or snap into each other and the bone replacement material becomes reinforced as desired. Earlier, the plates can also be deformed and adapted to the treatment scenario through elastic deformation of the planar structure101,111,121. After interlocking with or snapping into at least one further plate (which usually is also deformed), the two plates, thus connected to each other, stabilise each other to the effect that the selected shape is reinforced.

In this context, the plates become connected to each other in appropriate manner such that free gaps between the mutually connected plates remain in the regions of the pins102,112,122the mushrooms104,114,124and the grooves107,117,127such that the three-dimensional body formed from the plates is open-pored in the directions parallel to the plane of the plates. The plates have a cross-section and/or a thickness of approximately 5 mm and 10 mm such that the remaining pores have a free cross-section in the range between 0.5 mm and 1 mm. Said cross-section is sufficient to allow bone material to be formed in and/or to grow into the pores. The three-dimensional body with its open pores can therefore be called osteoconductive. The three-dimensional body formed from the plates is therefore well-suited as bone replacement material.

The pins102,112,122are thinnest in between the mushrooms104,114,124and the planar structure101,111,121, so the pins102,112,122may be tilted most easily, or respectively are most flexible, in the connection to the planar structure101,111,121, thereby allowing the mushrooms104,114,124to interlock with or snap into the grooves107,117,127in between the mushrooms104,114,124.

The plates should be pushed firmly into each other such that the three-dimensional body is dimensionally stable. In this context, the plates can interlock with each other in a first stage by the mushrooms104,114,124elastically deforming the pins102,112,122and because of the elastic restoring force of the pins102,112,122the mushrooms104,114,124or the edge of the mushrooms104,114,124respectively are pushed inside the grooves107,117,127thereby limiting the motion of neighbouring plates away from the planar structure101,111,121(seeFIGS. 35 to 37). When the plates are pushed further into each other (not shown), the plates can snap into each other in a second stage by the mushrooms104,114,124being pushed through the recesses103,113,123of the planar structures101,111,121. In this context, the mushrooms104,114,124can get lodged in the recesses103,113,123which prevents the mushrooms104,114,124from moving with respect to the neighbouring plate and thus snaps the two plates into each other. It is feasible just as well that, firstly, the edges of the mushrooms104,114,124plastically deform the pins102,112,122, the grooves107,117,127, the recesses103,113,123or the mushrooms104,114,124to a small extent or, secondly, that the edges of the recesses103,113,123plastically deform the mushrooms104,114,124of neighbouring plates to a small extent and that the plates are thus snapped into each other.

Moreover, two plates can be connected to each other through a first interlocking of the plates in some areas by means of the mushrooms104,114,124located at the tips of the pins102,112,122. Moreover, two plates can be connected to each other through interlocking the plates in some areas by means of the mushrooms104,114,124and by snapping them into each other in other areas by means of the mushrooms104,114,124and recesses103,113,123. Preferably, the dimensions of the mushrooms104,114,124, the depth of the recesses103,113,123(the thickness of the planar structure101,111,121respectively), and the length of the pins102,112,122between the planar structure101,111,121and the mushrooms104,114,124are adapted to each other appropriately such that, upon connection of the plates, the surfaces of the mushrooms104,114,124facing away from the planar structure101,111,121touch against the surface of the planar structure101,111,121of neighbouring plates and, upon connection of the plates, the surfaces of the mushrooms104,114,124facing away from the planar structure101,111,121touch against the gripping surface106,116,126of the mushrooms104,114,124of the neighbouring plate. As a result, the connected plates cannot move with respect to each other without deformation.

Accordingly, the tenth, eleventh and twelfth embodiments according toFIGS. 31 to 37differ from the one according toFIGS. 1 to 7mainly in that by the multiple mushrooms104,114,124located above on another the mushrooms104,114,124can interlock with one another in different positions, thereby allowing a bone replacement material can be built most accurate and with only small deviations in thickness. Furthermore more and more mushrooms104,114,124grab into grooves107,117,127of neighbouring plates while reducing the distance of the plates, thereby providing a more and more stable network.

The features of the invention disclosed in the preceding description and in the claims, figures, and exemplary embodiments, can be essential for the implementation of the various embodiments of the invention both alone and in any combination.

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