Bone implants

Abstract

The present invention relates to a bone implant having a main body in the form of a hollow body open on both axial sides and comprising or consisting of a load-bearing material, and an enclosure at least partially enclosing the main body on its outside and comprising or consisting of a bioerodible / bioabsorbable material, or a number of shaped bodies projecting radially from the main body and comprising or consisting of a bioerodible / bioabsorbable material. The invention further relates to a method for producing a bone implant, in particular a bone implant according to any of the preceding claims, characterized in that the bone implant is produced by an additive manufacturing process and / or in that a body in the form of a hollow body open on both axial sides and comprising or consisting of a load-bearing material is at least partially surrounded by an enclosure comprising or consisting of a bioerodible / bioabsorbable material by an additive manufacturing process or is connected to a number of shaped bodies comprising or consisting of a bioerodible / bioabsorbable material in such a way that the shaped bodies project radially from the body.

Description

Technical Field

[0001] The present invention relates to a bone implant, particularly for treating or dealing with bone defect sites and / or for fixing or securing joint implants, preferably knee joint implants.

Background Art

[0002] Generally, complex bone defect sites in joint replacement surgery are a major problem. This is particularly true when treating or dealing with complex tibial or femoral bone defect sites. The treatment or handling of such bone defect sites is further complicated by the fact that the shapes and / or geometries of the tibia (shinbone) and femur (thighbone) are naturally affected according to the patient's height, gender, and ethnic origin.

[0003] The treatment of complex joint bone defect sites generally involves two main goals: firmly fixing the bone implant used to treat or deal with the bone defect site to the bone bed with high primary stability and pursuing the reconstruction of the original biomechanical axis.

[0004] Conventional implants generally have the drawback of only reproducing the morphological conditions, particularly the shape and / or geometry and / or ratio, of bone defect sites, especially tibial or femoral bone defect sites, within a limited range. As a result, in order to optimally support the cortex, the shape and / or geometry and / or size of the bone defect site must be adapted to a specific implant. The associated (additional) bone loss then creates unfavorable starting conditions for any necessary replacement surgery.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The object of the present invention is to provide a bone implant that completely or partially avoids the drawbacks first described in relation to conventional bone implants. In particular, the bone implant must enable the treatment or handling of bone defects in a bone-friendly manner and reduce the risk of revision surgery. [Means for solving the problem]

[0006] This objective is achieved by a bone implant having the features described in independent claim 1 and by the method described in claim 15. Preferred embodiments of the present invention are dependent claims 2-14 and the subject matter of this specification. All claim language is incorporated herein by express reference.

[0007] According to a first aspect, the present invention provides a bone implant for preferably treating or managing bone defects, particularly tibia and / or femoral defects, and / or for fixing or abutting joint implants, particularly knee joint implants.

[0008] The bone implant comprises a body in the form of a hollow body with openings on both axial sides, containing or made of a load-bearing material, and at least partially, particularly partially or completely, the body or hollow body is surrounded on its outside, i.e., the outer surface of the body or hollow body, by a surrounding body containing or made of a biodegradable / bioabsorbable material, or by a number of molded bodies projecting radially from the body or hollow body containing or made of a biodegradable / bioabsorbable material.

[0009] In the context of this invention, the term "bone implant" should be understood to mean an implant for treating or managing bone defects, particularly bone defects of the tibia or femur, and / or for fixing or abutment of joint implants, particularly knee joint implants.

[0010] In the context of this invention, the term "molded body" should be understood to mean the body or component of a bone implant designed to fix, secure, or support a body or hollow body on or in the upper / middle part of a bone defect, particularly on or in the upper / middle part of a bone defect in the tibia or femur.

[0011] In the context of this invention, the expression "multiple molded bodies" should be understood to mean at least two, and more particularly two or more molded bodies, for example, two, three, four, five, six, seven, eight, nine, or ten or more molded bodies.

[0012] In the context of this invention, the term "bone defect" means a bone region affected by the loss or damage of bone tissue, particularly articular bone tissue, preferably knee or hip bone tissue. Bone loss or damage may be the result of fracture, bone trauma, necrosis, thinning (e.g., as a result of osteoporosis), bone diseases such as tumors, lack of mechanical stress (so-called stress shielding), or surgical intervention / re-intervention, particularly preferably revision after total knee or hip replacement.

[0013] In the context of this invention, the expressions "biodegradable / biodegradable" mean biodegradable or bioabsorbable.

[0014] In the context of this invention, the expression "non-biodegradable / non-biodegradable" means non-biodegradable or non-biodegradable.

[0015] In the context of this invention, the expression "in vivo degradation rate / in vivo absorption rate" means either the in vivo degradation rate or the in vivo absorption rate.

[0016] In the context of this invention, the term "load-bearing material" should be understood to mean a material that can withstand forces that typically occur in bones, particularly the tibia and / or femur, without deformation or fracture, or without significant deformation or fracture.

[0017] In the context of this invention, the expression "biodegradable material" should be understood to mean a material that can be metabolized in the body of a human or animal, particularly under the action of enzymes. The decomposition of the material can proceed all the way to mineralization, i.e., until the chemical components are released and incorporated into inorganic compounds (e.g., carbon dioxide and / or oxygen and / or ammonia), or it can remain at the stage of intermediates or conversion products that are decomposition stable.

[0018] In the context of this invention, the expression "bioabsorbable material" should be understood to mean a material that can be taken up into the body of a human or animal by living cells or tissues, such as the kidneys, without decomposition or significant degradation of the material.

[0019] In the context of this invention, the expression "animal body" should be understood to mean, for example, the body of a non-human mammal such as a horse, cow, goat, sheep, or pig, or a rodent such as a goat, rat, or mouse.

[0020] In the context of this invention, the expression "axially" should be understood to mean along the axis, particularly the axis of symmetry, of a component or body such as the body or hollow body and / or encasing of a bone implant.

[0021] In the context of this invention, the expression "longitudinal axis" should be understood to mean the axis of a component or body, such as the body or hollow body and / or encirclement of a bone implant, corresponding to the direction of the maximum extent of the component or body, such as the body or hollow body and / or encirclement.

[0022] In the context of this invention, the expression "radially" should be understood to mean a direction away from the point of symmetry, particularly the central point, and / or away from the axis of symmetry, particularly the central axis, of a component or body such as the body or hollow body and / or encasing of a bone implant, for example.

[0023] In the context of the present invention, the expression "proximal" should be understood to mean facing towards the center of the body or being located closer to the center of the body.

[0024] In the context of the present invention, the expression "distal" should be understood to mean pointing in the direction away from the center of the body or being located away from the center of the body.

[0025] In the context of the present invention, the expression "conical hollow body" should be understood to mean a hollow body having a side surface or a lateral surface, and the side surface or the lateral surface is at least partially, particularly only partially or completely inclined with respect to the axis of symmetry of the hollow body, particularly the central axis.

[0026] The present invention is distinguished in particular by the following advantages. The load-bearing material of the body or the hollow body enables particularly advantageous achievement of medically sufficient primary and secondary stability. Primary stability is generally understood to mean the fixation of the implant in the first few weeks after surgery, and this fixation is based on, for example, friction elements or fastening elements such as bone screws. Secondary stability is understood to mean the fixation of the implant based on osseointegration. Secondary stability generally begins approximately one month after the surgical procedure and can last for several years. Furthermore, the biodegradable / bioabsorbable material of the enclosure or the shaped body advantageously enables the biological reconstruction of the bone defect, and thus enables the reduction of the size of the bone defect. As a result, it is possible in particular to create improved starting conditions for any replacement surgery. A further advantage is that by selecting the biodegradable / bioabsorbable material of the enclosure or the shaped body, it is possible to specifically control the mechanical stability of the bone implant and particularly influence bone stimulation and bone growth. In particular, this makes it possible to balance the mechanical stability, bone stimulation, and bone growth of the bone implant against each other. The bone implant according to the present invention is particularly suitable for treating and / or handling bone defects in the tibia and / or femur.

[0027] In one embodiment of the present invention, the body or the hollow body has a cross-section that is non-angular, particularly circular, oval, or elliptical.

[0028] In a further embodiment of the present invention, the body or the hollow body is conical. The conical body or hollow body has the advantage of enabling more stable fixation of the extension shaft of the joint implant, in particular. Preferably, the body or the hollow body has a tapered cross-sectional area, particularly a continuously or discontinuously tapered cross-sectional area, and / or a tapered inner diameter, particularly a continuously or discontinuously tapered inner diameter, in the axial or longitudinal direction.

[0029] Alternatively, the body or the hollow body can have a constant cross-sectional area and / or a constant inner diameter in the axial or longitudinal direction, particularly over the entire aforementioned direction.

[0030] In principle, the body or the hollow body can have a constant, i.e., uniform, or variable, i.e., non-uniform, wall thickness, particularly in the axial or longitudinal direction. As a result, it is particularly advantageously possible to adapt to asymmetric bone defects.

[0031] In a further embodiment of the present invention, the body or the hollow body has a wall thickness of 1 mm to 30 mm, particularly 5 mm to 20 mm, preferably 8 mm to 15 mm.

[0032] Furthermore, the body or the hollow body can have a constant, i.e., uniform, or variable, i.e., non-uniform, shape, particularly in the axial or longitudinal direction. As a result, it is also (also) particularly advantageously possible to adapt to asymmetric bone defects.

[0033] Furthermore, the body or hollow body may have a number of openings or notches in the axial direction, particularly in the longitudinal direction, i.e., walls having only one opening / notch or multiple openings / notches. The openings / notches or openings / notches may be particularly U-shaped. Preferably, the walls of the body or hollow body have two openings / notches, particularly two opposing openings / notches. As a result, it is particularly advantageous that the knee joint implant can be placed in the body or hollow body. That is, the tibial component of the knee joint implant has a “wing” attached from the center outwards to maintain stable fixation and rotational stability.

[0034] In further embodiments of the present invention, the load-bearing material of the body or hollow body is a biodegradable / bioabsorbable material. As a result, particularly effective primary and secondary stability of the bone implant can be achieved with particular advantage.

[0035] Biodegradable / biodegradable materials are preferably selected from the group consisting of metals, alloys, ceramics, plastics, and combinations thereof, particularly mixtures.

[0036] The metal can be selected from the group consisting of tantalum, titanium, iron, zirconium, niobium, gold, and platinum. Titanium is particularly preferred.

[0037] The alloy can be selected from the group consisting of magnesium alloys, tantalum alloys, titanium alloys, chromium-cobalt alloys, chromium-cobalt-molybdenum alloys, iron alloys, steels such as stainless steel, zirconium alloys, niobium alloys, gold alloys, platinum alloys, and combinations thereof, especially mixtures. Titanium alloys, particularly Ti-6Al-4V, are especially preferred.

[0038] Plastics can be selected from the group consisting of polyetherketones, polyolefins, polyesters, polyamides, copolymers, and combinations thereof, especially mixtures (blends).

[0039] Polyether ketones can be selected from the group consisting of polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyether ether ether ketone (PEEEK), polyether ether ketone ketone (PEEKK), polyether ketone ether ketone ketone (PEKEKK), copolymers thereof, combinations thereof, and especially mixtures (blends) thereof. Polyether ether ketone (PEEK) is particularly preferred.

[0040] Polyolefins can be selected from the group consisting of polyethylene (PE), low-density polyethylene, high-density polyethylene, high-molecular-weight polyethylene (HMWPE), ultra-high-molecular-weight polyethylene (UHMWPE), polypropylene (PP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride, polyvinylidene chloride, polytetrafluoropropylene, polyhexafluoropropylene, copolymers thereof, and combinations thereof, in particular mixtures (blends) thereof.

[0041] Polyesters can be selected from the group consisting particularly of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, copolymers and combinations thereof, especially mixtures (blends).

[0042] In further embodiments of the present invention, the enclosing body is in the form of a layer or coating of a body or hollow body.

[0043] In a further embodiment of the present invention, the enclosing body has a thickness of 0.1 mm to 30 mm, particularly 1 mm to 10 mm, preferably 2 mm to 5 mm.

[0044] Furthermore, the enclosing body may have a constant, i.e., uniform thickness and / or a constant, i.e., uniform shape, particularly in the axial or longitudinal direction.

[0045] In further embodiments of the present invention, the enveloping body has a varying, i.e., non-uniform shape and / or thickness, particularly in the axial or longitudinal direction. As a result, it is particularly advantageous that it can be adapted to (similarly) asymmetrical bone defects.

[0046] In further embodiments of the present invention, the thickness of the enclosure is greater at one end than at the other end, particularly in the axial or longitudinal direction, and / or the thickness of the enclosure increases particularly continuously or discontinuously toward one end, particularly in the axial or longitudinal direction, and / or the thickness of the enclosure increases particularly continuously or discontinuously from one end to the other end, particularly in the axial or longitudinal direction.

[0047] If the bone implant is a tibial implant, i.e., an implant for treating or managing a bone defect in the tibia, the thickness of the burial body is preferably greater at the distal end of the burial body than at the proximal end, and / or the thickness of the burial body is preferably increased particularly continuously or discontinuously toward the distal end of the burial body

[0048] If the bone implant is a femoral implant, i.e., an implant for treating or managing a bone defect in the femur, the thickness of the burial body is preferably greater at the proximal end of the burial body than at the distal end, and / or the thickness of the burial body preferably increases particularly continuously or discontinuously toward the proximal end, and / or the thickness of the burial body preferably increases particularly continuously or discontinuously toward the proximal end, and / or the thickness of the burial body preferably increases particularly continuously or discontinuously toward the proximal end, and / or the thickness of the burial body preferably increases particularly continuously or discontinuously toward the proximal end, and / or the thickness of the burial body preferably increases particularly continuously or discontinuously toward the proximal end, and / or

[0049] In a further embodiment of the present invention, the main body or hollow body is not partially surrounded by the surrounding body on its outside.

[0050] In further embodiments of the present invention, the body or hollow body has a porous surface, particularly an open and / or microstructured surface. This can induce bone integration, i.e., the uptake or internal growth of natural bone tissue. This is particularly advantageous in promoting the stable fixation or integration of the body, and by extension, the bone implant on / in the bone defect. As a result, it is possible to improve secondary stability in particular. Furthermore, the uptake or internal growth of bone tissue advantageously leads to a reduction in the size of the bone defect.

[0051] Preferably, the porous surface of the body or hollow body, particularly the open surface, has pores having a diameter, particularly an average diameter, determined by scanning electron microscopy and / or mercury porosimetry, ranging from 10 μm to 400 μm, particularly 50 μm to 200 μm, preferably 100 μm to 135 μm. The pore diameters disclosed in this paragraph are particularly advantageous with respect to bone integration of the body or hollow body.

[0052] Furthermore, pores in the main body or hollow body, particularly surface pores, can be filled with biodegradable / bioabsorbable materials. The pores may be partially or completely filled with biodegradable / bioabsorbable materials. Preferably, the biodegradable / bioabsorbable materials filling the pores in the main body or hollow body, particularly surface pores, are different from those of the encasing or multiple molded bodies. As a result, multi-stage, e.g., two-stage, degradation or absorption kinetics of the bone implant can be produced. This is advantageously a further way to balance the mechanical stability, bone stimulation, and bone growth of the bone implant with respect to each other. With regard to suitable biodegradable / bioabsorbable materials, refer to the biodegradable / bioabsorbable materials disclosed in the following description in relation to encasings and multiple molded bodies.

[0053] The microstructured surface of the body or hollow body can be formed, for example, by a metallic structure, particularly a metallic lattice structure. Preferably, the metallic structure, particularly the metallic lattice structure, is a titanium structure, particularly a titanium lattice structure. The relevant titanium structure is commercially available, for example, under the name Structan®. Further suitable materials for the body or hollow body are referenced from the materials described above in relation to the body or hollow body.

[0054] In the context of this invention, the expression "microstructured surface" should be understood to mean a surface having structural elements, particularly in the form of depressions and / or ridges, wherein the structural elements have dimensions in micrometers, such as depth and / or height.

[0055] For example, the microstructured surface of the main body or hollow body may have depressions with a depth of 20 μm to 1000 μm, particularly 100 μm to 600 μm, preferably 300 μm to 400 μm, and / or ridges with a height of 20 μm to 1000 μm, particularly 100 μm to 600 μm, preferably 300 μm to 400 μm.

[0056] Furthermore, the surface of the body or hollow body can be formed by a coating of the body or hollow body. In other words, the surface of the body or hollow body may be the surface of a coating that coats or covers the body or hollow body. The coating can coat or cover the body or hollow body at least partially, especially only partially, or completely. Furthermore, the coating may have a thickness of 0.01 μm to 1000 μm, especially 1 μm to 100 μm, preferably 10 μm to 50 μm. Furthermore, the coating may have a porosity of 20% to 90%, especially 50% to 85%, preferably 60% to 80%. Preferably, the coating contains titanium, i.e., elemental or metallic titanium, or calcium phosphate, preferably hydroxyapatite. For example, the coating may be a pure titanium coating, i.e., a coating made of titanium. The relevant coatings can be manufactured, for example, by a method implemented by the applicant under the name Plasmapore®. Here, pure titanium powder is applied to the substrate to be coated by plasma coating under vacuum or negative pressure to a thickness of 150 μm and a porosity of 35% to 60%. For further suitable materials for coating, refer to the materials described above in relation to the body or hollow body.

[0057] In further embodiments of the present invention, the encirclement has a porous surface, particularly an open and / or microstructured surface. This can (similarly) induce bone integration and improve the secondary stability of the bone implant, and depending on the material of the encirclement, it can reduce the size of the bone defect. Preferably, the porous surface of the encirclement, particularly the open surface, has holes having a diameter, particularly an average diameter, determined by scanning electron microscopy and / or mercury porosimetry, of 20 μm to 1000 μm, particularly 50 μm to 500 μm, preferably 100 μm to 300 μm. The hole diameters disclosed in this paragraph are particularly advantageous with respect to bone integration of the encirclement.

[0058] Furthermore, the pores of the encirclement, particularly the surface pores, can be filled with biodegradable / bioabsorbable materials. The pores may be partially or completely filled with biodegradable / bioabsorbable materials. Preferably, the biodegradable / bioabsorbable material filling the pores of the encirclement, particularly the surface pores, is different from the biodegradable / bioabsorbable material of the encirclement. As a result, a multi-stage, e.g., two-stage, degradation or absorption kinetics of the bone implant can be formed. This is advantageously a further way to balance the mechanical stability, bone stimulation, and bone growth of the bone implant with respect to each other. With regard to suitable biodegradable / bioabsorbable materials, refer to the biodegradable / bioabsorbable materials disclosed in the following description in relation to the encirclement.

[0059] Furthermore, the microstructured surface of the enclosing body may have depressions with a depth of 20 μm to 1000 μm, particularly 100 μm to 600 μm, preferably 300 μm to 400 μm, and / or ridges with a height of 20 μm to 1000 μm, particularly 100 μm to 600 μm, preferably 300 μm to 400 μm.

[0060] Furthermore, the surface of the encirclement can be formed by a coating of the encirclement. In other words, the surface of the encirclement may be the surface of a coating that coats or covers the encirclement. The coating can coat or cover the encirclement at least partially, especially only partially, or completely. Furthermore, the coating can have a thickness of 0.01 μm to 1000 μm, especially 1 μm to 100 μm, preferably 10 μm to 50 μm. Furthermore, the coating can have a porosity of 20% to 90%, especially 50% to 85%, preferably 60% to 80%. With regard to suitable materials for the coating, the materials described further hereinafter in relation to the encirclement will be referenced.

[0061] In further embodiments of the present invention, only the molded body or a portion of the molded body has a porous surface, particularly an open and / or microstructured surface.

[0062] In particular, the porous surface of the molded body, especially the perforated surface, can have pores having a diameter, especially an average diameter, determined by scanning electron microscopy and / or mercury porosimetry, of 50 μm to 900 μm, especially 150 μm to 700 μm, and especially preferably 300 μm to 400 μm. The microstructured surface of the molded body can have depressions with a depth of 50 μm to 900 μm, especially 150 μm to 700 μm, preferably 300 μm to 400 μm, and / or ridges with a height of 50 μm to 900 μm, especially 150 μm to 700 μm, preferably 300 μm to 400 μm. As a result, bone integration, and depending on the material of the molded body, biological reconstruction, and thus reduction in the size of the bone defect being treated or managed, can be achieved (likewise) particularly advantageously.

[0063] Furthermore, pores in the molded body, particularly surface pores, can be filled with biodegradable / bioabsorbable materials. The pores can be partially or completely filled with biodegradable / bioabsorbable materials. Preferably, the biodegradable / bioabsorbable material filling the pores in the molded body, particularly surface pores, and the biodegradable / bioabsorbable material in the molded body are different from each other. As a result, the degradation or absorption kinetics of the bone implant can be produced in multiple stages, e.g., two stages. This is advantageous as a further way to balance the mechanical stability, bone stimulation, and bone growth of the bone implant with respect to each other. With regard to suitable biodegradable / bioabsorbable materials, refer to the biodegradable / bioabsorbable materials disclosed in the following description in relation to molded bodies.

[0064] Furthermore, porous surfaces, particularly open surfaces, of the molded body or a portion thereof can be formed by coating the molded body. The coating can coat or cover the molded body at least partially, particularly only partially, or completely. Furthermore, the coating can have a thickness of 0.01 μm to 1000 μm, particularly 1 μm to 100 μm, preferably 10 μm to 50 μm. Furthermore, the coating can have a porosity of 20% to 90%, particularly 50% to 85%, preferably 50% to 70%. For further suitable materials for coating, refer to the materials described below in relation to the molded body.

[0065] Furthermore, the molded body or some of the microstructured surfaces of the molded body may have depressions with a depth of 50 μm to 900 μm, particularly 150 μm to 700 μm, preferably 300 μm to 400 μm, and / or ridges with a height of 50 μm to 900 μm, particularly 150 μm to 700 μm, preferably 300 μm to 400 μm.

[0066] Furthermore, the molded body may have a thickness, i.e., wall thickness or height, of 1 mm to 30 mm, particularly 5 mm to 20 mm, preferably 8 mm to 15 mm, especially constant, i.e., uniform, or varying, i.e., non-uniform thickness, i.e., wall thickness or height. Advantageously, the total wall thickness of the bone implant can be controlled in a specific, and therefore application-dependent manner, through both the thickness of the molded body or the thickness of the surrounding body and the wall thickness of the main body or hollow body.

[0067] Furthermore, the molded body is preferably in the form of a sheet, i.e., the molded body preferably has a length and width greater than the thickness (height) of the molded body. Preferably, the molded body is plate-like and / or disc-like. In particular, each molded body may have two main faces arranged opposite to each other, each defined by two lateral faces arranged opposite to each other and two longitudinal faces arranged opposite to each other. In principle, the lateral faces are planar, i.e., flat or not curved, and / or curved, especially outwardly curved. Furthermore, in principle, the longitudinal faces are planar, i.e., flat or not curved, and / or curved, especially outwardly curved. For example, each molded body may have one curved, especially outwardly curved, longitudinal face, and separately, one planar longitudinal face and two planar lateral faces.

[0068] Furthermore, each molded body or several molded bodies may have at least one predetermined fracture line, in particular one predetermined fracture line only, or a plurality of predetermined fracture lines. The predetermined fracture lines preferably extend in the longitudinal direction of the molded body. The predetermined fracture lines may be, for example, in the form of perforations, notches, or scratches. As a result, the molded body, and by extension the bone implant, can be further adapted to the patient's specific bone defect. In particular, this can (further) reduce or completely avoid bone loss due to the adaptation of the bone defect to the bone implant.

[0069] In further embodiments of the present invention, the enveloping body comprises or consists of at least two different biodegradable / bioabsorbable materials, wherein these materials differ from one another in terms of their biodegradation / bioabsorption rates. As a result, further temporal control of the mechanical stability of the bone implant and the biological reconstruction of the bone defect can be achieved. In particular, this allows for a better balance between the mechanical stability of the bone implant, bone stimulation, and bone growth.

[0070] In further embodiments of the present invention, the molded body or some of the molded bodies each contain at least two different biodegradable / bioabsorbable materials, or the molded body or some of the molded bodies each consist of at least two different biodegradable / bioabsorbable materials, which differ from each other in terms of their biodegradation / bioabsorption rates. As a result, further temporal control of the mechanical stability of the bone implant and the biological reconstruction of the bone defect is (likewise) achievable. In particular, this allows for a better balance between the mechanical stability of the bone implant, bone stimulation, and bone growth.

[0071] In further embodiments of the present invention, biodegradable / bioabsorbable materials, particularly at least two different biodegradable / bioabsorbable materials, are selected from the group consisting of metals, polyhydroxyalkanoates, polycaprolactones, poly-p-dioxanones (poly-1,4-dioxan-2-ones), polymethylene terephthalate, calcium phosphate, calcium sulfate, calcium oxide (CaO), calcium hydroxide (Ca(OH)2), calcium carbonate (CaCO3), calcium citrate, calcium lactate, calcium acetate, calcium tartrate, calcium chloride (CaCl2), magnesium phosphate, magnesium sulfate, magnesium hydroxide (Mg(OH)2), magnesium hydroxide (e.g., as 4 MgCO3 × Mg(OH)2 × 5 H2 O), magnesium oxide (MgO), magnesium citrate (Mg3(C6 H5 O7)) or Mg(C6 H6 O7)), calcium magnesium carbonate (CaMg(CO3)2) and combinations thereof, particularly mixtures.

[0072] The metal is preferably magnesium.

[0073] Polyhydroxyalkanoates can be selected from the group consisting particularly of polylactides, polyglycolides, poly-3-hydroxybutyrates, poly-4-hydroxybutyrates, copolymers thereof, and combinations thereof, in particular mixtures (blends) thereof.

[0074] Calcium phosphate can be selected from the group consisting of tricalcium phosphate (TCP), such as α-tricalcium phosphate (α-TCP) and / or β-tricalcium phosphate (β-TCP); apatites, such as hydroxyapatite (HA), calcium-deficient hydroxyapatite (CdHA), substituted hydroxyapatite, non-stoichiometric hydroxyapatite, and nanoscale hydroxyapatite; tetracalcium phosphate (TTCP); monocalcium phosphate monohydrate (MCPM); monocalcium phosphate anhydride (MCPA); dicalcium phosphate anhydride (DCPA); dicalcium phosphate dihydrate (DCPD); octacalcium phosphate (OCP); amorphous calcium phosphate (ACP); calcium glycerophosphate; and combinations thereof, particularly mixtures.

[0075] Calcium sulfate can be selected from the group consisting of calcium sulfate (CaSO4), calcium sulfate hemihydrate (CaSO4 x 0.5 H2 O), calcium sulfate dihydrate (CaSO4 x 2 H2 O), and combinations thereof, especially mixtures.

[0076] Magnesium phosphate can be selected from the group consisting of magnesium hydrogen phosphate (MgHPO4), trimagnesium phosphate (Mg3(PO4)2), magnesium dihydrogen phosphate (Mg(H2PO4)2), magnesium glycerophosphate, and combinations thereof, particularly mixtures thereof, in particular, in hydrate or anhydrous form.

[0077] Particularly preferred is tricalcium phosphate as the biodegradable / biodegradable material. Tricalcium phosphate can be in crystalline form. In particular, tricalcium phosphate can have a degree of crystallinity of 50% to 99%, especially 75% to 95%. Furthermore, tricalcium phosphate may be microcrystalline tricalcium phosphate, i.e., tricalcium phosphate having microcrystals having at least one dimension in the micrometer range, especially >0.5 μm, especially 0.6 μm to 500 μm, preferably 0.6 μm to 100 μm. The at least one dimension may be the length and / or width and / or thickness or height and / or diameter of the microcrystal, especially the average diameter. Alternatively, tricalcium phosphate may be nanocrystalline tricalcium phosphate, i.e., tricalcium phosphate having microcrystals having at least one dimension in the nanometer range, especially 0.1 nm to 500 nm, preferably 0.1 nm to 100 nm. The at least one dimension may be the length and / or width and / or thickness or height and / or diameter of the microcrystal, especially the average diameter. Alternatively, tricalcium phosphate may be macrocrystalline tricalcium phosphate. Alternatively, tricalcium phosphate may be in an amorphous form. Furthermore, tricalcium phosphate may be phase-pure tricalcium phosphate. Here, the expression “phase-pure” should be understood to mean phase purity in the context of the relevant specification, particularly preferably according to ASTM F1088. Furthermore, tricalcium phosphate may have a porosity of <50%, particularly <20%, preferably <15%. Alternatively, tricalcium phosphate may be non-porous. Preferably, tricalcium phosphate is selected from the group consisting of α-tricalcium phosphate (α-TCP), β-tricalcium phosphate (β-TCP), and mixtures thereof. Particularly preferably, tricalcium phosphate is sintered tricalcium phosphate selected from the group consisting of sintered α-tricalcium phosphate (sintered α-TCP), sintered β-tricalcium phosphate (sintered β-TCP), and mixtures thereof.

[0078] Alternatively, biodegradable / bioabsorbable materials may be hydroxyapatite in particular. Hydroxyapatite may be in crystalline form. In particular, hydroxyapatite can have a crystallinity of 50% to 99%, especially 75% to 95%. Furthermore, hydroxyapatite may be microcrystalline hydroxyapatite, i.e., hydroxyapatite having microcrystals having at least one dimension in the micrometer range, especially >0.5 μm, especially 0.6 μm to 500 μm, preferably 0.6 μm to 100 μm. The at least one dimension may be the length and / or width and / or thickness or height and / or diameter of the microcrystal, especially the average diameter. Alternatively, hydroxyapatite may be nanocrystalline hydroxyapatite, i.e., hydroxyapatite having microcrystals having at least one dimension in the nanometer range, especially 0.1 nm to 500 nm, preferably 0.1 nm to 100 nm. At least one dimension may be the length and / or width and / or thickness of a microcrystal, or the height and / or diameter, particularly the average diameter. Alternatively, the hydroxyapatite may be macrocrystalline hydroxyapatite. Furthermore, the hydroxyapatite may be phase-pure hydroxyapatite. In this regard, the expression “phase-pure” should be understood to mean phase purity in the context of the relevant specification, particularly, preferably according to ASTM F1185. Furthermore, the hydroxyapatite may have a porosity of <50%, particularly <20%, preferably <15%. Low porosity means that high mechanical stability can be achieved. Alternatively, the hydroxyapatite may be non-porous. Furthermore, the hydroxyapatite may be sintered hydroxyapatite in particular.

[0079] Furthermore, the enclosing body and / or the molded body or a portion of the molded body may include or be composed of biodegradable / biodegradable materials. For suitable biodegradable / biodegradable materials, refer to the materials mentioned above in relation to the body or hollow body.

[0080] Furthermore, the enclosing body and / or the molded body or some of the molded bodies may include both biodegradable / bioabsorbable materials and bionon-biodegradable / bionon-bioabsorbable materials, or may consist of both biodegradable / bioabsorbable materials and bionon-biodegradable / bionon-bioabsorbable materials. For suitable biodegradable / bioabsorbable materials and bionon-biodegradable / bionon-bioabsorbable materials, refer entirely to the materials disclosed above.

[0081] Furthermore, bone implants can be manufactured by additive manufacturing processes. In particular, the encasing and / or molded body can be molded or bonded by additive manufacturing processes to the outside of the body or hollow body, i.e., to the outer surface of the body or hollow body. Further features and advantages of such methods are to be fully referenced by the following description made in the context of a second aspect of the present invention.

[0082] According to a second aspect, the present invention provides a method for manufacturing a bone implant, particularly a bone implant according to the first aspect of the present invention.

[0083] This method involves manufacturing bone implants by an additive manufacturing process, i.e., by 3D printing.

[0084] Alternatively, or in combination, a body in the form of an open or hollow body open on both sides in the axial direction, containing or consisting of a load-bearing material, and being at least partially, particularly partially or completely, enclosed, particularly integrally enclosed, by an enclosure containing a biodegradable / bioabsorbable material, by an additive manufacturing process, i.e., 3D printing, or connected, particularly integrally connected, to a plurality of molded bodies containing or consisting of a biodegradable / bioabsorbable material, such that the molded bodies protrude or project radially from the body. The body or hollow body is preferably conical.

[0085] In the context of this invention, the terms “additive manufacturing process” or “3D printing” should be understood to mean a process for the rapid and cost-effective manufacture of models, samples, prototypes, tools, semi-finished products, and final products, particularly bone implants. These processes are often also called “rapid prototyping.” Manufacturing is carried out directly by chemical and / or physical processes based on internal computer data models from intangible materials, such as liquids, melts, or powders, or from shape-neutral materials, such as tape-like or wire-like materials.

[0086] Additive manufacturing processes offer the advantage of particularly influencing bone implants with respect to material and / or shape and / or geometric shape and / or surface structure.

[0087] The additive manufacturing process can be selected from the group consisting of powder bed processes, free-space processes, and liquid material processes.

[0088] The powder bed process can be selected from the group consisting of selective laser melting, selective laser sintering, selective thermal sintering, binder injection, and electron beam melting.

[0089] Free-space processes can be selected from the group consisting of melt deposition modeling, LOM processes (Layered Object Modeling processes), metal coating, wax deposition modeling, contour grafting, cold spraying, and electron beam melting.

[0090] Liquid material processes can be selected from a group consisting of stereolithography, DLP (digital photopolymerization), and LCM (liquid crystal manufacturing) processes.

[0091] The LCM process can be a liquid composite molding process or a lithography-based ceramic manufacturing process. Further features and advantages of this method, particularly of the bone implant, body, casing, and molded body, are fully referenced from the descriptions made in the context of the first aspect of the present invention. The descriptions made in this regard also apply mutatis mutandis to the method according to the second aspect of the present invention. [Brief explanation of the drawing]

[0092] Further features and advantages of the present invention will become apparent from the claims and from the following description of preferred exemplary embodiments of the invention, which are described below with reference to the drawings. [Figure 1] One embodiment of the bone implant according to the present invention is schematically shown. [Figure 2] Further embodiments of the bone implant according to the present invention are schematically shown. [Figure 3] Further embodiments of the bone implant according to the present invention are schematically shown. [Modes for carrying out the invention]

[0093] (Detailed explanation of the drawing) The bone implant 1, schematically shown in Figure 1, comprises a main body 10 and a surrounding body 20.

[0094] The main body 10 is open on both sides in the axial direction A, or is open, and is preferably a conical, hollow body.

[0095] The main body 10 includes or consists of a load-bearing material. The load-bearing material is preferably a biodegradable / bioabsorbable material such as a titanium alloy, or a plastic such as polyetheretherketone. As a result, sufficient primary and secondary stability of the bone implant 1 after it has been placed on / inside the bone defect is particularly advantageously achievable. Further suitable materials for the main body 10 are described in the general description.

[0096] Preferably, as shown in Figure 1, the body 10 is completely surrounded or enclosed by the encirclement 20. The encirclement 20 contains or consists of biodegradable / bioabsorbable material. The biodegradable / bioabsorbable material may be, for example, calcium phosphate, particularly β-tricalcium phosphate and / or hydroxyapatite. Alternatively, the biodegradable / bioabsorbable material may be a polymer such as polycaprolactone, or a metal such as magnesium. Further suitable materials for the encirclement 20 are described in general.

[0097] The (at least partially) biodegradable / bioresorbable circumcision 20 makes the biological reconstruction of bone defects to be treated or addressed, such as bone defects in the tibia or femur, particularly advantageous. A particular advantage is that the size of the bone defect can be minimized by the biological reconstruction. This reduces the risk of any revision surgery. The reduction in bone defect size can create more favorable starting conditions for successfully performing revision surgery.

[0098] The main body 10 can have a wall thickness of, for example, 3 mm to 5 mm, while the surrounding body 20 can have a casing thickness of, for example, 2 mm to 10 mm.

[0099] As shown in Figure 1, the encircling body 20 can have a uniform thickness. Alternatively, the encircling body can have a non-uniform thickness (not shown), particularly in the axial or longitudinal direction. As a result, the structure of an asymmetrical bone defect can be considered in particular.

[0100] Furthermore, the encirclement 20 may have an open surface. Alternatively, the encirclement 20 may be completely open or open throughout. With the two embodiments described above for the encirclement 20, bone integration, i.e., the incorporation of bone tissue into and / or internal growth of bone tissue onto and / or within the encirclement 20, is particularly advantageously achievable. This, in turn, contributes to further improvement of the primary and secondary stability of the bone implant 1.

[0101] Furthermore, the encirclement, particularly its region or layer, may contain multiple different biodegradable / biodegradable materials that differ from one another in terms of biodegradation / biodegradation rates. As a result, various degradation / absorption kinetics of the encirclement 20, in particular, control of the mechanical stability, bone stimulation, and bone growth of the bone implant 1, are particularly advantageous.

[0102] Figure 2 shows a further embodiment of the bone implant 1 according to the present invention.

[0103] The bone implant 1 comprises a main body 10 and a surrounding body 20 that partially encloses the main body 10.

[0104] The body 10 is open on both sides in the axial direction A, or is open, and is preferably in the form of a conical, hollow body. The body 10 contains or consists of a load-bearing material. The load-bearing material is preferably a biodegradable / bioabsorbable material such as a titanium alloy, particularly a titanium alloy Ti-6Al-4V. This is a titanium alloy containing titanium, aluminum, and vanadium, and optionally impurities, particularly in the form of iron and / or oxygen and / or carbon and / or nitrogen and / or hydrogen, or consists of titanium, aluminum, and vanadium, and optionally impurities, particularly in the form of iron and / or oxygen and / or carbon and / or nitrogen and / or hydrogen. Preferably, the titanium alloy consists of titanium, 5.5% to 6.75% by mass, particularly 6% by mass, of aluminum; 3.5% to 4.5% by mass, particularly 4% by mass, of vanadium; optionally, 0.4% by mass, of iron, and / or 0.2% by mass, of oxygen, and / or 0.08% by mass, of carbon, and / or 0.05% by mass, of nitrogen, and / or 0.015% by mass, of hydrogen, or any of the aforementioned elements / components. In particular, the body 10 may preferably have a lattice structure made of Ti-6Al-4V. Further suitable materials for the body 10 are described in general and in Figure 1.

[0105] Since the main body 10 is only partially contained by the enclosing body 20, the thickness of the bone implant 1 can be advantageously controlled depending on the application. Preferably, the unenclosed region 12 of the bone implant 1 is intended to receive an extension shaft (not shown) of an articular implant. If the bone implant 1 is a tibial implant, the unenclosed portion 12 is the proximal portion of the bone implant. In contrast, if the bone implant 1 is a femoral implant, the unenclosed portion 12 is the distal portion of the bone implant.

[0106] For further features and advantages of bone implant 1, particularly the main body 10 and the surrounding body 20, refer to the description in Figure 1 in full to avoid repetition. The features and advantages described for bone implant 1, particularly the main body 10 and the surrounding body 20, also apply mutatis mutandis to bone implant 1 shown in Figure 2.

[0107] Figure 3 shows a further embodiment of the bone implant 1 according to the present invention.

[0108] The bone implant system 1, schematically shown in Figure 3, comprises a main body 10 and a number of molded bodies 20. Six molded bodies 20 are shown as an example. However, it will be understood that the bone implant 1 may also include fewer or more molded bodies.

[0109] The main body 10 is a conical hollow body with openings on both sides in the axial direction A.

[0110] The body 10 comprises or consists of load-bearing materials, particularly titanium alloys, e.g., Ti-6Al-4V, or plastics, particularly polyetheretherketones. As a result, sufficient primary and secondary stability can be achieved, particularly advantageously. Further suitable materials for the body 10 are described in general terms, as well as in the descriptions of Figures 1 and 2.

[0111] Preferably, the main body 10 comprises a wall 11 having two preferably opposing openings or notches 12. The openings or notches 12 are preferably U-shaped.

[0112] The molded body 20 contains or is composed of biodegradable / bioabsorbable material. As a result, biological reconstruction of the bone defect can be achieved particularly advantageously. Biological reconstruction of the bone defect advantageously minimizes the size of the bone defect. This, in turn, reduces the risk of revision surgery and / or creates favorable conditions for successfully performing revision surgery. Biodegradable / bioabsorbable material may be, for example, calcium phosphate, particularly β-tricalcium phosphate and / or hydroxyapatite. Alternatively, biodegradable / bioabsorbable material may be a polymer such as polycaprolactone, or a metal such as magnesium.

[0113] Further suitable materials for the enclosure 20 are described in general terms and in the descriptions of Figures 1 and 2. The molded body 20 protrudes radially from the main body 10. The molded body 20 is integrally connected to or joined to the main body 10. For example, the molded body 20 can be bonded or welded to the main body 10. Alternatively, the molded body 20 can be molded externally, i.e., on the outer surface 12 of the main body 10, by an additive manufacturing process.

[0114] The molded body 20 is preferably in the form of a sheet, particularly in the form of a plate or a disc. This means that the molded body 20 has a length and width smaller than the thickness (height) of the molded body 20. Preferably, each molded body 20 has two main faces arranged opposite to each other, each of which is defined by two lateral faces arranged opposite to each other and two longitudinal faces arranged opposite to each other.

[0115] To improve bone integration of the bone implant 1, it may be even more preferable that each of the molded bodies 20 has a porous surface, particularly perforations and / or a microstructured surface, or is made of a porous material, particularly a perforated material. For suitable materials in this regard, please refer to the general description as well as the descriptions in Figures 1 and 2.

Claims

1. 1. A bone implant comprising: a body in the form of a hollow body open on both axial sides, the body comprising or consisting of a load-bearing material; an enclosure at least partially surrounding the body on its exterior, the enclosure comprising or consisting of a bioerodible / bioabsorbable material; or a plurality of molded bodies projecting radially from the main body and including or consisting of a biodegradable / bioabsorbable material; including bone implants.

2. 2. The bone implant according to claim 1, characterized in that the body has a non-angular, in particular circular, oval or elliptical cross section.

3. 3. A bone implant according to claim 1 or 2, characterized in that the body is conical and has an at least partially tapered inner diameter.

4. Bone implant according to any of the preceding claims, characterized in that the body has a wall thickness of 1 mm to 30 mm, in particular 5 mm to 20 mm, preferably 8 mm to 15 mm.

5. A bone implant according to any of the preceding claims, characterized in that the load-bearing material of the body is a non-biodegradable / non-bioabsorbable material.

6. 10. A bone implant according to any of the preceding claims, in particular claim 5, characterized in that the load-bearing material, in particular the non-biodegradable / non-bioabsorbable material, is selected from the group consisting of metals such as titanium and / or tantalum, alloys such as titanium alloys, ceramics, plastics, polyetherketones, polyetheretherketones, polyetherketoneketones, polyetheretheretherketones, polyetheretherketoneketones, polyetherketoneetherketoneketones, polyolefins, and combinations thereof.

7. A bone implant according to any of the preceding claims, characterized in that the surrounding body is in the form of a layer or coating on the body.

8. A bone implant according to any of the preceding claims, characterized in that the surrounding body has a thickness of 0.1 mm to 30 mm, in particular 1 mm to 10 mm, preferably 2 mm to 5 mm.

9. 10. A bone implant according to any of the preceding claims, characterized in that the surrounding body has a non-uniform shape and / or thickness in the axial direction.

10. 10. The bone implant of claim 9, wherein the thickness of the surround is greater at one end of the surround than at the other end of the surround and / or the thickness of the surround increases towards one end of the surround.

11. 10. A bone implant according to any of the preceding claims, characterized in that the body is not partly surrounded by the surrounding body on its outside.

12. 10. A bone implant according to any of the preceding claims, characterized in that the body and / or the surrounding body and / or the shaped body have a porous surface, in particular an open-pore and / or a microstructured surface.

13. A bone implant according to any of the preceding claims, characterized in that the surrounding body comprises at least two different biodegradable / bioabsorbable materials that differ from each other in terms of their biodegradation / bioabsorption rates, or the shaped bodies each comprise two different biodegradable / bioabsorbable materials that differ from each other in terms of their biodegradation / bioabsorption rates.

14. A bone implant according to any of the preceding claims, in particular claim 13, characterized in that the biodegradable / bioabsorbable materials, in particular the at least two different biodegradable / bioabsorbable materials, are selected from the group consisting of polyhydroxyalkanoates, such as polylactide and / or polyglycolide, polycaprolactone, calcium phosphates, such as β-tricalcium phosphate and / or hydroxyapatite and / or combinations thereof.

15. 10. A method for producing a bone implant, in particular a bone implant according to any of the preceding claims, comprising the steps of: the bone implant is manufactured by an additive manufacturing process; and / or 10. A method according to claim 1, wherein a body in the form of a hollow body open on both axial sides and comprising or consisting of a load-bearing material is at least partially surrounded by an enclosure comprising or consisting of a bioerodible / bioabsorbable material by said additive manufacturing process, or is connected to a number of shaped bodies comprising or consisting of a bioerodible / bioabsorbable material such that said shaped bodies project radially from said body.

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