Augmentation device, composite and method for producing a composite

Description

[0001] The invention relates to an augmentation material comprising a wire and, in axial alignment along the wire, a plurality of groups of connecting elements extending radially from the wire and axially adjacent, wherein the connecting elements are designed such that when a first group from the plurality of groups is pressed against another group from the plurality of groups, the connecting elements of the two groups can be connected to one another in a form-fitting and / or force-fitting manner.

[0002] The invention further relates to a composite comprising the augmentation material and a bone cement as well as a method for producing a composite.

[0003] The invention particularly relates to an alloplastic augmentation material for use in joint endoprosthesis operations, in particular revision joint endoprosthesis operations.

[0004] The augmentation material according to the invention is intended for filling and stabilizing cavities, in particular bone cavities, such as a bone canal. For this purpose, the augmentation material can be formed as a composite with a bone cement. Background of the invention

[0005] Augmentation materials have long been known and are used extensively clinically (JM Rueger: Knochenersatzmittel, Orthopäde 27 (1998) 72-79). The augmentation materials used to date are generally volume-stable, but not dimensionally stable. One exception is an augmentation material marketed by Zimmer under the name "Trabecular Metal™<" and known, for example, from WO 2013 / 074 909 A1. This material has a porous structure that mimics the structure of human spongiosa (sponge tissue). This material contains tantalum and is commercially available in defined shapes and sizes. The material cannot be changed in shape and size in the operating room and cannot be processed with conventional tools in the operating room. Therefore, the specific anatomical situation of the patient can only be taken into account to a limited extent.The medical user can only try to adapt the patient's implant bed to the given geometry or to insert an approximately suitable implant and close the existing gaps with allogeneic bone material or other volume fillers.

[0006] Patent EP 3 092 076 B1 describes a particulate alloplastic augmentation material for producing a freely formed porous body. When pressed together, the individual particles of the augmentation material interlock to create a freely formable porous body, which can then be filled with bone cement to produce a composite. A disadvantage of particulate augmentation material is that it is unsafe to use during surgery. For example, care must be taken to ensure that the particles do not inadvertently reach unwanted locations in the patient's body, which could hinder the surgical procedure or, in the worst case, lead to health complications for the patient. Furthermore, forming the freely formed porous body from a particulate material is time-consuming, which is particularly disadvantageous in time-critical operations.Loose particles, especially those that have fallen onto the operating room floor, also represent a significant potential for accidents.

[0007] In the patent specification US 9 943 411 B2, an augmentation material is disclosed which comprises a wire and, in axial alignment along a longitudinal axis of the wire, a plurality of groups of connecting elements extending radially from the wire and axially adjacent, wherein the connecting elements are designed such that when a first group from the plurality of groups is pressed against another group from the plurality of groups, the connecting elements of the two groups can be connected to one another in a form-fitting and / or force-fitting manner. Tasks

[0008] An object of the present invention is to at least partially overcome one or more of the disadvantages resulting from the prior art.

[0009] In particular, an augmentation material is to be provided that can be freely shaped easily, quickly, and safely and is suitable for filling bone cavities. The augmentation material should be able to follow the contour of the cavity. After shaping, the augmentation material should form a stable, porous body without the need for chemical curing reactions, such as radical polymerization. After shaping, the bone substitute material should have open porosity and be mechanically stable. The porosity and size of the pores should be sufficient and suitable for human bone of a patient treated with the bone substitute material to grow into the pores. Furthermore, the pores should be suitable for stabilization by infiltration with a bone cement paste, in particular with a PMMA bone cement paste.The augmentation material should be able to form a pressure-stable composite with the bone cement. Overheating of the composite during the curing of the bone cement paste, especially the PMMA bone cement paste, which could damage the patient's tissue, should be avoided. The volume of the augmentation material should be manageable using tools available in operating rooms, such as scissors or forceps.

[0010] It is a further object of the invention to provide a composite which can be produced simply, quickly and freely formable using the augmentation material and avoids limitations of conventional composites.

[0011] Another object of the invention is to provide a method for producing a composite which avoids limitations of conventional methods for producing a composite. Preferred embodiments of the invention

[0012] A contribution to at least partially achieving at least one of the aforementioned objects is made by the features of independent claims 1 and 8, by which the invention is defined. The dependent claims provide preferred embodiments that contribute to at least partially achieving at least one of the objects.

[0013] The invention comprises an augmentation material comprising a wire and, in axial alignment along a longitudinal axis of the wire, a plurality of groups of axially adjacent connecting elements extending radially from the wire, wherein the connecting elements are designed such that when a first group from the plurality of groups is pressed against another group from the plurality of groups, the connecting elements of the two groups can be connected to one another in a form-fitting and / or force-fitting manner, wherein the connecting elements are designed as disks extending radially from the wire.

[0014] In one embodiment of the augmentation material, axially adjacent connecting elements in a group have an axial connecting element spacing from one another which corresponds to at least one axial connecting element extension of a connecting element along the longitudinal axis of the wire.

[0015] In one embodiment of the augmentation material, the discs are perforated, the discs have an open-pore structure, or the discs are perforated and have an open-pore structure.

[0016] In one embodiment of the augmentation material, a group of connecting elements comprises 3 to 20, preferably 3 to 15, more preferably 5 to 15 axially adjacent connecting elements.

[0017] In one embodiment of the augmentation material, axially adjacent, in particular directly axially adjacent, groups of connecting elements have an axial group distance from one another which corresponds to at least twice the axial extension of a connecting element along the longitudinal axis of the wire.

[0018] The augmentation material can be produced using a generative 3D printing process.

[0019] A further embodiment of the invention is a composite comprising an augmentation material according to one of the preceding embodiments of the invention and a bone cement, in particular a PMMA bone cement, wherein the augmentation material is enclosed, in particular completely enclosed, by the bone cement, in particular by the PMMA bone cement.

[0020] In one embodiment of the composite, the augmentation material in the composite occupies a volume fraction in the range of 30-70 volume percent based on the volume of the composite.

[0021] A further embodiment of the invention is a method for producing a composite, in particular a composite according to the twelfth or thirteenth embodiment of the invention, for filling a cavity, in particular a cavity in a bone, in particular a bone canal, comprising the steps a. Providing the augmentation material in an arrangement that substantially corresponds to the shape of the cavity; b. Applying a bone cement paste into the spaces between the augmentation material so that the augmentation material is completely enclosed by the bone cement paste; and c. Curing the bone cement paste to form the composite. General

[0022] In this description, range specifications also include the values ​​referred to as limits. A specification such as "in the range from X to Y" with reference to a quantity A therefore means that A can assume the values ​​X, Y, and values ​​between X and Y.

[0023] Unilaterally limited ranges of the type "up to Y" for a size A accordingly mean the value Y and less than Y.

[0024] Some of the described features are linked to the term "essentially." The term "essentially" is to be understood in such a way that, under real-world conditions and manufacturing techniques, a mathematically precise interpretation of terms such as "superposition," "perpendicular," "diameter," or "parallelism" can never be exact, but only within certain manufacturing error tolerances. For example, "essentially perpendicular axes" enclose an angle of 85 degrees to 95 degrees to each other, and "essentially equal volumes" encompass a deviation of up to 5% by volume. A "device consisting essentially of plastic," for example, comprises a plastic content of ≥95 to ≤100% by weight. A "substantially complete filling of a volume B," for example, encompasses a filling of ≥95 to ≤100% by volume of the total volume of B. Detailed description

[0025] The subject matter of the invention relates to an augmentation material comprising a wire and, in axial alignment along a longitudinal axis of the wire, a plurality of groups of axially adjacent connecting elements extending radially from the wire, wherein the connecting elements are designed such that when a first group from the plurality of groups is pressed against another group from the plurality of groups, the connecting elements of the two groups, i.e. the first group and the another group from the plurality of groups, can be connected to one another in a form-fitting or non-positive manner or in a form-fitting and non-positive manner, wherein the connecting elements are designed as disks extending radially from the wire.

[0026] The augmentation material comprises a wire. A wire is defined as a plastically deformable, elongated body. The wire can be formed as a single piece or composed of several, for example, two to ten, wire elements, optionally with one or more additional inserts. For example, the wire can be composed of several twisted and / or braided wire elements. Due to its ease of manufacture, a single-piece wire is preferred.

[0027] The wire can have different cross-sectional geometries, such as square, in particular square or hexagonal, oval or star-shaped, with round cross-sectional geometries being preferred due to the simpler manufacturing process.

[0028] The wire diameter is preferably in the range of 0.1 mm to 2 mm, more preferably in the range of 0.2 mm to 1.5 mm. This allows for easy deformation of the wire, and thus of the augmentation material, into the desired shape, while maintaining a certain stability of the porous body formed from the augmentation material. Furthermore, such a wire diameter allows for easy shortening of the wire, and thus of the augmentation material, using tools readily available in an operating room, such as forceps or scissors.

[0029] The wire preferably has a length in the range of 10 cm to 50 cm, more preferably in the range of 10 cm to 40 cm. This allows for filling common cavity sizes during surgery.

[0030] A plurality of groups of axially adjacent connecting elements extend radially from the wire at an angle in a range of 60°-120° to the longitudinal axis of the wire.

[0031] A connecting element is understood to be a structural elevation on or in the outer surface of the wire. In one embodiment, the wire and the connecting elements are connected to one another in a form-fitting and / or force-fitting manner. In another embodiment, the wire and the connecting elements are connected to one another by a material fit. In another preferred embodiment, the wire and the connecting elements are formed as a single piece, with the outer surface of the wire itself being formed as the plurality of connecting elements. The latter is preferred due to its simpler and more cost-effective manufacturing method.

[0032] Connecting elements are axially adjacent if they are arranged at or on different positions along the longitudinal axis of the wire.

[0033] The connecting elements are arranged in a plurality of groups, i.e., at least two groups, with each group comprising at least a plurality of adjacent connecting elements arranged axially along the longitudinal axis of the wire. The plurality of groups of connecting elements can be arranged relative to one another in such a way that they appear as a single large group of connecting elements.

[0034] The connecting elements are shaped in such a way that when two groups of connecting elements are pressed against each other, a positive connection, a frictional connection, or a positive and frictional connection between the connecting elements of the two groups is achieved. The connecting elements of the groups interlock to form a positive and / or frictional connection. The pressing of two groups of connecting elements against each other can be made possible, for example, by deforming the wire. For example, the wire can be bent or wound so that the two groups of connecting elements are connected to each other at the two axially opposite ends of the wire, and thus of the augmentation material. In one embodiment, the connection between the groups is reversible, so that they can be separated from each other again. In another embodiment, the connection is irreversible, so that it cannot be separated without causing damage.

[0035] The flexible wire allows the augmentation material to be quickly, easily, and safely introduced into any shaped porous body, particularly for filling bone cavities. The connecting elements allow the stabilization of the porous body thus formed without the augmentation material spontaneously returning to its original shape. The augmentation material thus shaped forms a porous body, with the pores of the porous body forming the spaces between the connecting elements and the shaped wire.

[0036] Since the augmentation material is made in one piece, it can be used safely during surgery.

[0037] To adapt the augmentation material to the size of the cavity to be filled, the wire can be shortened at any point, especially between axially adjacent connecting elements. Depending on the material used for the wire, this can be done using scissors or pliers, for example.

[0038] The axial spacing between fasteners, i.e., the axial distance between two axially adjacent fasteners in a group, can take on different values. Due to the simpler manufacturing process, all fasteners in a group have the same axial spacing.

[0039] In one embodiment of the augmentation material, axially adjacent connecting elements in a group have an axial connecting element spacing from one another that corresponds to at least one axial connecting element extension along the longitudinal axis of the wire. The axial connecting element spacing is the distance between two connecting elements at the level of the wire, running parallel to the longitudinal axis of the wire.

[0040] The connecting elements can be formed with uneven thickness along their radial extension, which runs essentially perpendicular to the longitudinal axis of the wire. For example, the connecting elements can have an axial extension directly adjacent to the wire, which decreases with increasing radial distance from the wire. This is the case, for example, with connecting elements that are formed as disc-like disks concentrically formed around the wire. The axial connecting element extension is understood to be the axial extension of the part of the connecting element with the greatest radial distance from the wire.

[0041] The axial connecting element spacing preferably has a value that lies in a range of 1 to 2 times, preferably 1.05 to 1.8 times, the value of the axial connecting element extension. This enables easy insertion of a connecting element of a first group between two axially adjacent connecting elements of a further group of connecting elements, forming a positive and / or frictional connection between the connecting elements. In particular, a precisely fitting, positive connection between pressed-against-one-other connecting elements can be formed, for example, when the axial connecting element spacing corresponds to the axial connecting element extension. If the axial connecting element spacing has a value less than 1 times the axial connecting element extension, the formation of a positive and / or frictional connection between the pressed-against-one-other connecting elements is made more difficult.If the axial connecting element distance is greater than twice the axial connecting element extension, the holding force of the frictional connection of the connecting elements pressed against each other is reduced and the porous body formed from the augmentation material loses stability.

[0042] Preferably, the connecting elements have an axial connecting element extension in a range of 0.05 mm to 1.5 mm, preferably in a range of 0.5 to 1 mm, in order to ensure good handling of the augmentation material.

[0043] In one embodiment of the augmentation material, the connecting elements are formed as discs extending radially from the wire. Due to the ease of manufacture and ease of application, it is preferred that the discs be arranged substantially concentrically around the wire. The disc-shaped connecting elements allow for pressing against each other over the entire radial circumference of the wire, so that a wide variety of shaped porous bodies can be easily achieved using the augmentation material.

[0044] The discs can have differently shaped cross-sectional geometries.

[0045] For example, the discs can have an elliptical, angular, in particular square, pentagonal or hexagonal shape, whereby discs with a round cross-sectional geometry are preferred due to the simpler manufacturing process.

[0046] The connecting elements designed as discs can have a closed, smooth surface structure.

[0047] In one embodiment of the augmentation material, the connecting elements shaped as discs are perforated and thus have one or more passages in the axial direction along the longitudinal axis of the wire. In one embodiment, the connecting elements shaped as discs have an open-pore structure. In one embodiment, the connecting elements shaped as discs are perforated and have an open-pore, sponge-like structure. The aforementioned embodiments allow for improved ingrowth of newly formed bone tissue, both into the spaces of the shaped porous body, and thus into the spaces between the wire and the discs, as well as into the perforations and / or into the open-pore structure of the individual discs. In addition, interlocking with bone cement is improved by such connecting elements.

[0048] In an exemplary embodiment of the augmentation material not according to the invention, the connecting elements are designed as pins extending radially from the wire. Pins are understood to be elongated structural units whose longitudinal axis forms an angle with the longitudinal axis of the wire in the range of 60° to 120°. Due to ease of manufacture, it is preferred if the longitudinal axis of the pins and the longitudinal axis of the wire are substantially perpendicular to each other. It is preferred if all pins have the same pin length and the same pin diameter.

[0049] The pins can be arranged on or at the wire in such a way that each pin has one or two axially adjacent pins, so that a maximum of one pin is arranged at any given cross-sectional plane of the wire. For example, all pins can point in the same direction as viewed from the wire, as is the case with the teeth of a comb, starting from its handle.

[0050] In an exemplary embodiment not according to the invention, several, in particular 4 to 10, preferably 6 to 8, extend.

[0051] Pins radially adjacent from the wire. Thus, several, in particular 4 to 10, preferably 6 to 8, pins are arranged in the corresponding cross-sectional planes of the wire. The radially adjacent pins extend from the wire in a disc-like or star-shaped manner, essentially in one plane. This enables an improved positive and / or non-positive connection between pins pressed against one another from different groups of connecting elements. In particular, the groups of connecting elements can be positively and / or non-positively connected to one another from variable directions and angles to one another, thus giving the user of the augmentation material greater freedom in designing the porous body formed from the augmentation material.

[0052] The pins can be formed in different lengths in order to form a positive and / or non-positive connection between them.

[0053] In an exemplary embodiment of the augmentation material not according to the invention, the pins extend radially from the wire with a pin length that corresponds to at least three times the wire diameter. This allows the formation of the most stable porous body possible from the augmentation material. To avoid complicating handling of the augmentation material, it is preferred if the pin length does not correspond to more than ten times the wire diameter.

[0054] The pins can have different cross-sectional geometries, such as square, in particular square, pentagonal, or hexagonal, oval, or round, with a round cross-sectional geometry being preferred due to its ease of manufacture. In particular, the pins can be cylindrical, with the pin end facing away from the wire being angular or round, in particular hemispherical.

[0055] In order to further improve the positive and / or non-positive connection of the pins when two groups of pins are pressed against one another, the pins in an exemplary embodiment of the augmentation material not according to the invention comprise mushrooms, i.e. mushroom-shaped, substantially hemispherical structural units projecting beyond the actual pin diameter, hooks, loops, undercuts and / or locking elements or the pins are designed as mushrooms, hooks, loops, undercuts and / or locking elements.

[0056] For example, the pins can be provided with mushrooms, i.e. mushroom-shaped structural units, particularly at the end of the pin opposite the wire, so that the mushrooms of the pins from different groups pressed against each other engage with each other like barbs and thus form the connection of the pins more stable than would be the case without mushrooms.

[0057] In one embodiment of the augmentation material, a group of connecting elements comprises 3 to 20, preferably 3 to 15, more preferably 5 to 15 axially adjacent connecting elements.

[0058] For example, a group of connecting elements comprises 10 axially adjacent disks. In addition to the axially adjacent connecting elements, particularly in the case of connecting elements in the form of pins not according to the invention, the axially adjacent connecting elements can comprise additional radially adjacent connecting elements. For example, a group can comprise 10 axially adjacent pins, each of these 10 axially adjacent pins having a further 5 radially adjacent pins, each of which lies essentially in the same cross-sectional plane of the wire as the corresponding axially adjacent pins. Such a group of connecting elements thus comprises a total of 60 pins.

[0059] The groups of fasteners can be arranged so close to each other axially that they appear like one large group of fasteners.

[0060] In one embodiment of the augmentation material, axially adjacent groups of connecting elements have an axial group spacing from one another that corresponds to at least twice the axial extension of a connecting element along the longitudinal axis of the wire. The axial group spacing is the distance between two groups of connecting elements running parallel to the longitudinal axis of the wire.

[0061] This allows for improved flexibility of the wire and at the same time ensures that the porous body formed from the augmentation material has a higher number and larger pores, which allows for improved ingrowth of bone tissue into the porous body and / or improved penetration of bone cement dough into the porous body.

[0062] The augmentation material can be produced in different ways.

[0063] In one embodiment of the augmentation material, the augmentation material can be produced using a generative 3D printing process.

[0064] A particularly preferred example of a 3D printing process is selective laser melting (SLM). Other rapid prototyping processes or computer-aided generative manufacturing processes can also be used to produce the augmentation material, such as fused layer modeling / manufacturing (FLM), fused deposition modeling (FDM), laminated object modeling (LOM) of plastic films, layer laminated manufacturing (LLM) of plastic films, electron beam melting (EBM) of plastics or metals, multi-jet modeling (MJM) of plastics, selective laser sintering (SLS) of plastics or metals, and stereolithography (STL or SLA).

[0065] The augmentation material can comprise or consist of different materials. For example, the augmentation material can be made of biocompatible plastic, stainless steel, titanium, a titanium alloy, tantalum, a tantalum alloy, or composites of these materials.

[0066] These materials are particularly well-suited for medical purposes and can also be used to achieve suitable elastic properties for the connecting elements. Augmentation materials made of metal or metal alloys can be produced by selective laser sintering or by melting with electron beams, preferably using a 3D printing process.

[0067] The biocompatible plastic can be biodegradable. Polylactides, polyglycolides, polycaprolactones, and polyesters, which are formed from various α-hydroxycarboxylic acids, can be used for this purpose. Non-biodegradable plastics include polyamides, polyimides, polyether ketones, and polysulfones. Augmentation materials made from these non-biodegradable and degradable plastics can be produced by selective laser sintering.

[0068] A further subject matter of the invention relates to a composite comprising an augmentation material according to one of the preceding embodiments and a bone cement, in particular a PMMA bone cement, wherein the augmentation material is enclosed, in particular completely enclosed, by the bone cement.

[0069] To produce the composite, the augmentation material is enclosed, in particular completely enclosed, in a bone cement dough, which then hardens to form a bone cement.

[0070] A bone cement paste is a substance suitable in the field of medical technology for creating a stable connection between artificial joints, such as hip and knee joints, and bone material and / or for stabilizing vertebral bodies. Upon hardening, a bone cement paste becomes a bone cement. These bone cements are preferably polymethyl methacrylate bone cements (PMMA bone cements) or inorganic bone cements. PMMA bone cements have long been used in medical applications and date back to the work of Sir Charnley (cf. Charnley, J. Anchorage of the femoral head prosthesis of the shaft of the femur. J. Bone Joint Surg. 1960; 42, 28-30.). PMMA bone cements can be produced from a powder component comprising a bone cement powder as the first starting component and a liquid component comprising a monomer liquid as the second starting component.With a suitable composition, the two starting components can be stored separately. When the two starting components are brought into contact, swelling of the polymer components of the bone cement powder creates a plastically deformable bone cement paste. This initiates radical polymerization of the monomer. As the monomer polymerization progresses, the viscosity of the bone cement paste increases until it completely hardens.

[0071] A bone cement powder is understood to be a powder comprising at least one particulate polymethyl methacrylate and / or a particulate polymethyl methacrylate copolymer. Examples of copolymers are styrene and / or methyl acrylate. In one embodiment, the bone cement powder can additionally comprise a hydrophilic additive that supports the distribution of the monomer liquid within the bone cement powder. In another embodiment, the bone cement powder can additionally comprise an initiator that initiates the polymerization. In another embodiment, the bone cement powder can additionally comprise an X-ray opaque. In yet another embodiment, the bone cement powder can additionally comprise pharmaceutically active substances, such as antibiotics.

[0072] The bone cement powder preferably comprises, as a hydrophilic additive, at least one particulate polymethyl methacrylate and / or a particulate polymethyl methacrylate copolymer, an initiator, and a radiopaque, or consists of these components. Further preferably, the bone cement powder comprises, or consists of, at least one particulate polymethyl methacrylate and / or a particulate polymethyl methacrylate copolymer, an initiator, a radiopaque, and a hydrophilic additive. Most preferably, the bone cement powder comprises, or consists of, at least one particulate polymethyl methacrylate and / or a particulate polymethyl methacrylate copolymer, an initiator, a radiopaque, a hydrophilic additive, and an antibiotic.

[0073] The particle size of the particulate polymethyl methacrylate and / or the particulate polymethyl methacrylate copolymer of the bone cement powder of the sieve fraction can be less than 150 µm, preferably less than 100 µm. The hydrophilic additive can be particulate and / or fibrous.

[0074] In a further embodiment, not according to the invention, the hydrophilic additive can be sparingly soluble, preferably insoluble, in methyl methacrylate. In a further embodiment, not according to the invention, the hydrophilic additive can have an absorption capacity of at least 0.6 g of methyl methacrylate per gram of hydrophilic additive. In a further embodiment, not according to the invention, the hydrophilic additive can comprise a chemical substance with at least one OH group. In this case, it can preferably be provided that the hydrophilic additive has covalently bonded OH groups on its surface. Examples of such preferred hydrophilic additives can be additives selected from the group comprising cellulose, oxycellulose, starch, titanium dioxide and silicon dioxide, with pyrogenic silicon dioxide being particularly preferred. In a non-inventive

[0075] In one embodiment, the particle size of the hydrophilic additive of the sieve fraction can be less than 100 µm, preferably less than 50 µm, and most preferably less than 10 µm. The hydrophilic additive can be present in an amount of 0.1 to 2.5 wt.% based on the total weight of the bone cement powder.

[0076] The initiator may contain dibenzoyl peroxide or consist of dibenzoyl peroxide.

[0077] A radiopaque agent is a substance that allows bone cement to be visible on X-ray images. Examples of radiopaque agents include barium sulfate, zirconium dioxide, and calcium carbonate.

[0078] The pharmaceutically active substance may comprise one or more antibiotics and, optionally, added cofactors for the one or more antibiotics. Preferably, the pharmaceutically active substance consists of one or more antibiotics and, optionally, added cofactors for the one or more antibiotics. Examples of antibiotics include gentamicin, clindamycin, and vancomycin.

[0079] The monomer liquid can comprise the monomer methyl methacrylate or consist of methyl methacrylate. In one embodiment, the monomer liquid comprises, in addition to the monomer, an activator dissolved therein, such as N,N-dimethyl-p-toluidine, or consists of methyl methacrylate and N,N-dimethyl-p-toluidine. An inorganic bone cement is understood to be a bone cement based on calcium phosphates and calcium sulfate dihydrate. Powders of calcium phosphates and / or calcium sulfate dihydrate are used as the powder component, which can be cured by a liquid component comprising an aqueous solution of various salts. A variety of inorganic bone cements have been described, of which the following are examples: EP 1 592 463 B1, EP 2 271 585 B1, and EP 2 988 789 B1.

[0080] The bone cement particularly fills the spaces between the porous body formed from the augmentation material.

[0081] The composite forms a pressure-stable, non-porous body into which no bone tissue can grow.

[0082] The composite can have different volume ratios of augmentation material to bone cement.

[0083] In one embodiment of the composite, the augmentation material in the composite occupies a volume fraction in the range of 30 volume percent to 70 volume percent, preferably a volume fraction of 35 volume percent to 65 volume percent, based on the volume of the composite. Due to the volume fraction of at least 30 volume percent of augmentation material, the composite can be produced using a bone cement paste, in particular a PMMA bone cement paste, without the bone cement paste, in particular the PMMA bone cement paste, heating up during curing to such an extent that surrounding patient tissue could be thermally damaged. At volume fractions of over 70 volume percent of augmentation material, the structural stability of the composite is reduced.

[0084] Another object of the invention relates to a process for producing a composite according to the invention comprising the steps a. Providing the augmentation material in an arrangement that substantially corresponds to the shape of the cavity; b. Applying a bone cement paste into the spaces between the augmentation material so that the augmentation material is completely enclosed by the bone cement paste; and c. Curing the bone cement paste to form the composite.

[0085] One step of the method involves providing the augmentation material. Providing the augmentation material in an arrangement that essentially corresponds to the shape of the cavity can be carried out in different ways. For example, the augmentation material can be wound spirally around an implant shaft of an implant, such as a hip joint endoprosthesis, which is to be inserted into a bone canal. The augmentation material essentially follows the contour of the corresponding bone canal and serves to fill the space between the implant and the wall of the bone canal. The augmentation material can be arranged such that its groups of connecting elements are connected to one another in a form-fitting and / or force-fitting manner. This simplifies the provision of the augmentation material because, for example, the stability of the body formed from the augmentation material is increased.Excess, unneeded augmentation material can be easily removed by trimming the wire, for example, with scissors or pliers. If the inserted wire of the augmentation material is not long enough, an additional augmentation material can be quickly and easily connected to the original wire by pressing the respective connecting elements together.

[0086] When the augmentation material is provided essentially in the form of the cavity, it forms a stable porous body.

[0087] The spaces between the augmentation material, i.e., the spaces between the formed wire and the unbonded and interconnected connecting elements, are filled in a further step by applying a bone cement paste, in particular a PMMA bone cement paste, such that the augmentation material is essentially completely enclosed by the bone cement paste. The porous body formed from the augmentation material is essentially completely filled with and enclosed by the bone cement paste.

[0088] In a further step of the process, the bone cement dough hardens to form the composite.

[0089] The procedure can be carried out entirely outside the cavity to be filled.

[0090] In an embodiment of the method not according to the invention, the augmentation material is provided in the cavity to be filled and both the application of the bone cement dough into the spaces between the augmentation material and the hardening of the bone cement dough take place in the cavity to be filled.

[0091] For example, the augmentation material is provided in a bone canal by winding it spirally following the contour of the bone canal. Preferably, groups of connecting elements are pressed against one another to form a stable porous body, particularly in the form of a hollow cylinder. In a further step, this porous body is filled within the bone canal with a bone cement paste so that the porous body is essentially completely enclosed by the bone cement paste. Before the bone cement paste hardens, a corresponding implant is inserted into the bone canal such that a shaft of the implant is surrounded by the augmentation material. The bone cement paste then hardens, forming the composite.

[0092] The features and combinations of features disclosed for the augmentation material are also disclosed for the composite and the method and vice versa. Figures

[0093] The invention is further illustrated below by means of exemplary figures. The invention is not limited to the figures.

[0094] It shows Fig. 1 a schematic plan view of a section of an augmentation material with a plurality of groups of connecting elements, Fig. 2 the augmentation material from Figure 1 in a perspective side view, Fig. 3 a further schematic top view of the augmentation material from the Figures 1 and 2 with connected groups of connecting elements, Fig. 4 shows a further embodiment of an augmentation material in a schematic plan view, Fig. 5 shows the augmentation material from Figure 4 in a perspective side view, Fig. 6 a further embodiment of an augmentation material in a schematic plan view, Fig. 7 the augmentation material from Figure 6in a perspective side view, Fig. 8 a further schematic top view of the augmentation material from the Figures 6 and 7 with connected groups of connecting elements, Fig. 9 shows an embodiment of an augmentation material not according to the invention in a perspective side view, Fig. 10 shows an embodiment of an augmentation material not according to the invention in a perspective side view, Fig. 11 shows a further embodiment of an augmentation material in a perspective side view, and Fig. 12 shows a flow diagram of a method for producing a composite. Description of the characters

[0095] Figure 1shows a schematic plan view of a section of an augmentation material 100. The augmentation material 100 comprises a wire 200 and, along the longitudinal axis of the wire 200, a plurality of groups 350 of connecting elements 300 extending radially from the wire 200 and axially adjacent (provided with reference numerals only as an example), wherein in Figure 1only five of the groups 350 are shown. Each of the groups 350 comprises four axially adjacent connecting elements 300 in the form of round, disc-like disks, which are arranged concentrically around the wire 200. The wire 200 and the connecting elements 300 are designed as a single piece. Within a group 350, the axially adjacent connecting elements 300 have an axial connecting element spacing 310 (provided with reference numerals only as an example), which corresponds approximately to one and a half times an axial connecting element extension 320 (provided with reference numerals only as an example).

[0096] Connecting element spacing 310 corresponds to the distance between two axially adjacent connecting elements 300 of a group 350 at the level of the wire 200 and thus to the path of the wire 200 between these connecting elements 300. The axial connecting element extension 320 corresponds to the axial extension of the connecting elements 300 at the end of the connecting elements 300 radially facing away from the wire 200.

[0097] The individual groups 350 have an axial group spacing 360 (provided with reference numerals merely as an example) from one another, which is three times the connecting element spacing 310. The axial group spacing 360 corresponds, analogously to the axial connecting element spacing 310, to the spacing between two axially adjacent groups 350 at the level of the wire and thus to the path length of the wire 200 between these groups 350. The axial group spacing 360 enables a high degree of flexibility of the augmentation device 100 and allows the formation of a porous body from the augmentation material 100.

[0098] Figure 2 shows the section of the augmentation material 100 from Figure 1 in a perspective side view.

[0099] Figure 3 shows a further schematic plan view of a section of the augmentation material 100 from the Figures 1 and 2, wherein the augmentation material 100 is shaped in such a way, in particular by deforming the wire 200, that a first group 350a of connecting elements 300a is positively and non-positively connected to a second group 350b of connecting elements 300b of the augmentation material 100.

[0100] By adjusting the connecting element spacing 310 (cf. Figure 1 ) to connecting element extension 320 (cf. Figure 1 ) a positive connection of the connecting elements 300a, 300b of the two groups 350a, 350b is permitted.

[0101] The connection of the two groups 350a, 350b shown as well as further groups not shown enables the formation of a porous body using the

[0102] Augmentation material 100. This porous body formed from the augmentation material 100 can be used to fill cavities, in particular bone canals, and to form a composite from the augmentation material 100 and a bone cement, in particular a PMMA bone cement.

[0103] Figure 4 shows a schematic plan view of a section of another embodiment of an augmentation material 100'. The embodiment of the augmentation material 100' largely corresponds to the embodiments described above and in the Figures 1 to 3 illustrated embodiment, so that to avoid repetition, reference is made to the above description. Modifications of a variant of the Figures 1 to 3 shown embodiment have the same reference numeral with an additional apostrophe.

[0104] The axial group spacing 360' (provided with reference symbols only as an example) of the groups 350' (provided with reference symbols only as an example) of connecting elements 300' (provided with reference symbols only as an example) of the augmentation material 100' corresponds to the axial connecting element spacing 310' (provided with reference symbols only as an example) of connecting elements 300' within a group 350', so that the groups 350' appear like a single, large group of connecting elements 300'.

[0105] Figure 5 shows the augmentation material 100' from Figure 4 in a perspective side view.

[0106] Figure 6 shows a schematic plan view of a section of another embodiment of an augmentation material 100". The embodiment of the augmentation material 100" largely corresponds to the augmentation material described above and in the Figures 1 to 5illustrated embodiments, so that to avoid repetition, reference is made to the above description. Modifications of a variant of the Figures 1 to 5 The embodiments shown have the same reference numeral with two apostrophes.

[0107] Compared to the embodiment of the augmentation material 100' according to the Figures 4 and 5 indicates the Figure 6 The embodiment shown has a smaller axial connecting element extension 320" (provided with reference numerals only as an example) of the individual connecting elements 320".

[0108] Figure 7 shows the augmentation material 100'' from Figure 6 in a perspective side view.

[0109] Figure 8 shows a further schematic plan view of a section of the augmentation material 100" from the Figures 6 and 7, wherein the augmentation material 100" is shaped in such a way, in particular by deforming the wire 200", that a first group 350a" of connecting elements 300a" ​​engages with a second group 350b" of connecting elements 300b" of the augmentation material 100" in order to non-positively connect the groups 350a", 350b" upon displacement of the groups 350a", 350b" along the longitudinal axis of the wire 200". Due to the axial connecting element extension 320" being small compared to the axial connecting element spacing 310", the groups 350a", 350b" form no or only partial positive connection.

[0110] Figure 9 shows a plan view of a section of another embodiment of an augmentation material 100‴ not according to the invention. The embodiment of the augmentation material 100‴ largely corresponds to the augmentation material 100‴ described above and in the Figures 1 to 8illustrated embodiments, so that to avoid repetition, reference is made to the above description. Modifications of a variant of the Figures 1 to 8 The embodiments shown have the same reference numeral with three apostrophes.

[0111] The connecting elements 300‴ (provided with reference numerals only as an example) of the embodiment according to Figure 9 are shaped like pins and not as in the above embodiments according to the Figures 1 to 8in the form of discs. Each of the axially adjacent groups 350‴ (provided with reference numerals purely as an example) of connecting elements 300‴ in the form of pins has five axially adjacent pins, each of these pins having a further seven radially adjacent pins. Each of the groups 350‴ thus has a total of 40 connecting elements 300‴ in the form of pins. A group 350‴ thus comprises five subgroups of eight radially adjacent connecting elements 300‴ in the form of pins, the subgroups of eight radially adjacent pins each extending radially out of the wire 200‴ in a cross-sectional plane of the wire 200‴. In order to be able to effectively connect the connecting elements 300‴ in the form of pins of two groups 350‴ with each other in a force-locking manner, the pins have a pin length of 330, which corresponds to three times a wire diameter 210 of the wire 200‴.The individual groups 350" are analogous to the augmentation material 100 of the . Figures 1 to 3 spaced apart from each other.

[0112] Figure 10 shows a perspective side view of a further embodiment of an augmentation material 10"" not according to the invention. The embodiment of the augmentation material 100' largely corresponds to the augmentation material 100' described above and in the Figures 1 to 9 illustrated embodiments, so that to avoid repetition, reference is made to the above description. Modifications of a variant of the Figures 1 to 9 The embodiments shown have the same reference numeral with four apostrophes. The connecting elements 300‴ (provided with reference numerals only as an example) of the embodiment according to Figure 10 are in the form of pins, similar to the connecting elements according to the embodiment of Figure 9, formed. The connecting elements 300"" in the form of pins each have a mushroom 340 at an end opposite the wire. The mushrooms 340 engage with each other when two groups 350"" of connecting elements 300"" are pressed against each other, so that the augmentation material 100"" can form a very stable porous body.

[0113] Figure 11 shows a perspective side view of another embodiment of an augmentation material 100‴. The embodiment of the augmentation material 100‴" largely corresponds to the embodiments described above and in the Figures 1 to 10 illustrated embodiments, so that to avoid repetition, reference is made to the above description. Modifications of a variant of the Figures 1 to 10The embodiments shown have the same reference numeral with five apostrophes. The connecting elements 300"‴ are designed as wedge-shaped discs, enabling a good force-locking connection of the groups 350"‴ when pressed against each other.

[0114] Figure 12shows a flow diagram of a method 400 for producing a composite comprising the augmentation material 100, 100', 100", 100‴, 100"", 100‴" and a bone cement with the steps 410 to 430. The composite is used to fill a cavity. In step 410, the augmentation material 100, 100', 100'', 100‴, 100", 100‴" is provided in the form of a porous body which essentially corresponds to the shape of the cavity. For this purpose, the augmentation material 100, 100', 100", 100‴, 100"", 100‴" can be shortened, for example by means of scissors or pliers, so that the shape of the cavity can be reproduced as closely as possible.To form the shape of the cavity, it is preferred that two or more of the groups 350, 350', 350", 350‴, 350"", 350‴" of connecting elements 300, 300', 300", 300‴, 300"", 300"‴ are pressed against one another so that they interact in a form-fitting and / or force-fitting manner and thus structurally stabilize the porous body made of augmentation material 100, 100', 100", 100‴, 100"", 100‴".

[0115] In step 420, a bone cement dough is applied into the interstices of the porous body formed and provided from the augmentation material 100, 100', 100'', 100‴, 100", 100‴", so that the interstices are filled with bone cement dough and the augmentation material 100, 100', 100", 100‴, 100"", 100‴" is enclosed by the bone cement dough.

[0116] In step 430, the bone cement dough surrounding the porous body of augmentation material 100, 100', 100", 100‴, 100"", 100‴" hardens to form the composite. In the process, the bone cement dough transforms into bone cement.

[0117] The composite produced in this way is inserted into the cavity to be filled, especially a bone canal.

[0118] In an embodiment of the method 400 not according to the invention, the provision 410 of the augmentation material 100, 100', 100", 100‴, 100"", 100‴" takes place in the cavity to be filled, in particular a bone canal. In step 420, the bone cement dough is applied to the augmentation material 100, 100', 100'', 100‴, 100", 100‴" provided in the cavity in the form of a porous body, so that the interstices are filled with bone cement dough and the augmentation material 100, 100', 100", 100‴, 100", 100‴" is enclosed by the bone cement dough. The curing 430 of the bone cement dough to form the composite also takes place in the cavity to be filled. Reference symbol

[0119] 100, 100', 100" 100‴, 100"", 100‴"Augmentation material 200, 200', 200" 200"', 200"", 200"‴Wire 210Wire diameter 300, 300', 300" 300‴, 300"", 300"‴Connector 300aConnectors first group 300bConnectors further group 310, 310', 310"Axial connector spacing 320, 320', 320"Axial connector extension 330Pin length 340Mushroom 350, 350', 350" 350‴, 350"", 350"‴Group of fasteners 350a, 350a''First group of fasteners 350b, 350b''Further group of fasteners 360, 360', 360"Axial group spacing 400Process for producing a composite 410Providing 420Applying 430Curing

Claims

1. An augmentation material (100, 100', 100", 100‴") comprising a wire (200, 200', 200", 200‴") and, in axial alignment along a longitudinal axis of the wire (200, 200', 200", 200""'), a plurality of groups (350, 350', 350", 350‴ʺ) of axially adjacent connecting elements (300, 300', 300", 300‴ʺ) which extend radially from the wire (200, 200', 200", 200‴ʺ), the connecting elements (300, 300', 300", 300‴") being designed such that, when a first group (350a, 350") of the plurality of groups (350, 350', 350", 350‴ʺ) presses against a further group (350b, 350") of the plurality of groups (350, 350', 350", 350‴ʺ), the connecting elements (300a, 300a", 300b, 300b") of the two groups (350a, 350a" 350b, 350b") can be connected to one another in a form-fitting and / or force-fitting manner, characterized in that the connecting elements (300, 300', 300", 300‴") are designed as discs which extend radially from the wire (200, 200', 200", 200‴ʺ).

2. The augmentation material (100, 100', 100", 100‴") according to claim 1, wherein axially adjacent connecting elements (300, 300', 300", 300‴ʺ) in a group (350) have an axial connecting element spacing (310, 310', 320") from one another, which spacing corresponds to at least one axial connecting element extension (320, 320', 320") of a connecting element (300, 300', 300", 300‴") along the longitudinal axis of the wire (200, 200', 200", 200‴ʺ).

3. The augmentation material (100, 100', 100", 100""') according to claim 1 or 2, wherein the discs are perforated and / or have an open-pore structure.

4. The augmentation material (100, 100', 100", 100‴") according to any of the preceding claims, wherein a group (350, 350', 350", 350‴") of connecting elements (300, 300', 300", 300‴") comprises 3 to 20 axially adjacent connecting elements (300, 300', 300", 300‴ʺ).

5. The augmentation material (100) according to any of the preceding claims, wherein axially adjacent groups (350) of connecting elements (300) have an axial group spacing (360) from one another, which spacing corresponds to at least twice the axial extension of a connecting element (300) along the longitudinal axis of the wire (200).

6. A composite comprising an augmentation material (100, 100', 100", 100""') according to any of the preceding claims 1 to 5 and a bone cement, in particular a PMMA bone cement, wherein the augmentation material (100, 100', 100", 100‴") is surrounded by the bone cement.

7. The composite according to claim 6, wherein the augmentation material (100, 100', 100", 100""') in the composite occupies a volume fraction in the range of 30-70 percent by volume, based on the volume of the composite.

8. A method (400) for producing a composite according to either of claims 6 or 7 for filling a cavity, comprising the steps of a. providing (410) the augmentation material (100, 100', 100", 100‴") in an arrangement which substantially follows the contour of the cavity; b. applying (420) a bone cement paste into gaps in the augmentation material (100, 100', 100", 100‴ʺ), so that the augmentation material (100, 100', 100", 100‴") is completely surrounded by the bone cement paste; and c. hardening (430) the bone cement paste to form the composite.