BONE IMPLANT

Abstract

A bone implant includes a main body in the form of a hollow body open on both sides in the axial direction. The main body includes a load-bearing material. An encasing body at least partially encases the main body on the outside and includes an in vivo degradable/in vivo resorbable material. Alternatively, the encasing body includes a multiplicity of shaped bodies protruding from the main body in the radial direction that include an in vivo degradable/in vivo resorbable material. A method for producing the bone implant includes an additive manufacturing process. The main body can be at least partially encased by the encasing body in the additive manufacturing process.

Claims

1. A bone implant comprising: a main body comprising a hollow body open on both sides in an axial direction, the main body comprising a load-bearing material; and an encasing body which at least partially encases an outside of the main body, the encasing body comprising at least one in vivo degradable/in vivo resorbable material, or a plurality of shaped bodies which protrude from the main body in a radial direction and comprise the at least one in vivo degradable/in vivo resorbable material.

2. The bone implant according to claim 1, wherein the main body has a corner-free cross section.

3. The bone implant according to claim 1, wherein the main body is conical and has an at least sectionally tapering inner diameter.

4. The bone implant according to claim 1, wherein the main body has a wall thickness of 1 mm to 30 mm.

5. The bone implant according to claim 1, wherein the load-bearing material is an in vivo nondegradable/in vivo nonresorbable material.

6. The bone implant according to claim 1, wherein the load-bearing material is selected from the group consisting of metals, alloys, ceramics, plastics, and combinations thereof.

7. The bone implant according to claim 1, wherein the encasing body comprises a layer or coating on the main body.

8. The bone implant according to claim 1, wherein the encasing body has a thickness of 0.1 mm to 30 mm.

9. The bone implant according to claim 1, wherein the encasing body has a nonuniform shape and/or a non-uniform thickness in the axial direction.

10. The bone implant according to claim 1, wherein the encasing body has a thickness, the thickness being a first thickness at a first end of the encasing body and a second thickness at a second end of the encasing body, and wherein at least one of: the first thickness is greater than the second thickness; and the thickness of the encasing body increases toward the first end of the encasing body.

11. The bone implant according to claim 1, wherein the main body is partially exposed and not encased by the encasing body on the outside of the main body.

12. The bone implant according to claim 1, wherein at least one of the main body and the encasing body comprises a porous and/or microstructured surface.

13. The bone implant according to claim 1, wherein the at least one in vivo degradable/in vivo resorbable material comprises at least two in vivo degradable/in vivo resorbable materials which differ from one another with regard to their in vivo degradation rate/in vivo resorption rate, or the shaped bodies each comprise the at least two in vivo degradable/in vivo resorbable materials which differ from one another with regard to their in vivo degradation rate/in vivo resorption rate.

14. The bone implant according to claim 1, wherein the at least one in vivo degradable/in vivo resorbable material is selected from the group consisting of polyhydroxyalkanoates, calcium phosphates and combinations thereof.

15. A method for producing the bone implant according to claim 1, comprising the steps of: producing the bone implant by an additive manufacturing process; and/or producing the main body by the additive manufacturing process, and at least partially encasing the main body with the encasing body.

16. The bone implant according to claim 1, wherein the main body has a circular, oval or elliptical cross section.

17. The bone implant according to claim 1, wherein the load-bearing material is selected from the group consisting of titanium, tantalum, titanium alloys, polyetherketones, polyetheretherketone, polyetherketoneketone, polyetheretheretherketone, polyetheretherketoneketone, polyetherketoneetherketoneketone, polyolefins and combinations thereof.

18. The bone implant according to claim 1, wherein the main body and/or the encasing body and/or the shaped bodies have an open-pored surface.

19. The bone implant according to claim 1, wherein the in vivo degradable/in vivo resorbable material is selected from the group consisting of polylactide, polyglycolide, polycaprolactone, β-tricalcium phosphate, hydroxyapatite and combinations thereof.

20. The bone implant according to claim 13, wherein the at least two in vivo degradable/in vivo resorbable materials are selected from the group consisting of polyhydroxyalkanoates, calcium phosphates and combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Further features and advantages of the invention will become apparent from the claims and from the following description of preferred exemplary embodiments of the invention, which are explained below with reference to the figures, where:

[0102] FIG. 1 schematically shows one embodiment of a bone implant according to the invention,

[0103] FIG. 2 schematically shows a further embodiment of a bone implant according to the invention and

[0104] FIG. 3 schematically shows a further embodiment of a bone implant according to the invention.

DETAILED DESCRIPTION

[0105] The bone implant 1 depicted schematically in FIG. 1 comprises a main body 10 and an encasing body 20.

[0106] The main body 10 is in the form of a hollow body which is open or opened on both sides in the axial direction A and which is preferably conical.

[0107] The main body 10 comprises a load-bearing material or consists of a load-bearing material. The load-bearing material is preferably an in vivo nondegradable/in vivo nonresorbable material, such as, for example, a titanium alloy or a plastic, such as, for example, polyetheretherketone. As a result, sufficient primary and secondary stability of the bone implant 1, after it has been placed on/in a bone defect, is achievable with particular advantage. With regard to further suitable materials for the main body 10, reference is made to the general description.

[0108] Preferably, as depicted in FIG. 1, the main body 10 is completely surrounded or encased by the encasing body 20. The encasing body 20 comprises an in vivo degradable/in vivo resorbable material or consists of such a material. The in vivo degradable/in vivo resorbable material can, for example, be a calcium phosphate, in particular β-tricalcium phosphate and/or hydroxyapatite. Alternatively, the in vivo degradable/in vivo resorbable material can be a polymer, such as, for example, polycaprolactone, or a metal, such as, for example, magnesium. With regard to further suitable materials for the encasing body 20, reference is made to the general description.

[0109] Owing to the (at least partially) in vivo degradable/in vivo resorbable encasing body 20, biological reconstruction of a bone defect to be treated or managed, such as, for example, a tibial or femoral bone defect, is achievable with particular advantage. It is especially advantageous that the size of the bone defect can be minimized by the biological reconstruction. This reduces the risk of any revision surgery. Owing to the reduction in the size of the bone defect, more favorable starting conditions may be created for successful performance of revision surgery.

[0110] The main body 10 can, for example, have a wall thickness of 3 mm to 5 mm, whereas the encasing body 20 can, for example, have a casing thickness of 2 mm to 10 mm.

[0111] As depicted in FIG. 1, the encasing body 20 can have a uniform thickness. Alternatively, the encasing body can have a nonuniform thickness (not depicted), in particular in the axial direction or longitudinal direction. As a result, asymmetrical bone defect structures can, in particular, be taken into account.

[0112] Furthermore, the encasing body 20 can have an open-pored surface. Alternatively, the encasing body 20 can be completely open-pored or be open-pored throughout. Owing to the two aforementioned embodiments for the encasing body 20, osteointegration, i.e., take and/or ingrowth of bone tissue on and/or into the encasing body 20, is achievable with particular advantage. This in turn contributes to an additional improvement in the primary and secondary stability of the bone implant 1.

[0113] Furthermore, the encasing body, in particular regions or layers thereof, can comprise different in vivo degradable/in vivo resorbable materials which differ from one another with regard to their in vivo degradation rate/in vivo resorption rate. As a result, different degradation/resorption kinetics of the encasing body 20 and, in particular, control of the mechanical stability of the bone implant 1, of bone stimulation and of bone growth are possible with particular advantage.

[0114] FIG. 2 shows a further embodiment of a bone implant 1 according to the invention.

[0115] The bone implant 1 comprises a main body 10 and an encasing body 20 which only partially surrounds the main body 10.

[0116] The main body 10 is in the form of a hollow body which is open or opened on both sides in the axial direction A and which is preferably conical. The main body 10 comprises a load-bearing material or consists of a load-bearing material. The load-bearing material is preferably an in vivo nondegradable/in vivo nonresorbable material, such as, for example, a titanium alloy, in particular the titanium alloy Ti-6Al-4V. This is a titanium alloy which comprises titanium, aluminum and vanadium and optionally impurities, in particular 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, in particular in the form of iron and/or oxygen and/or carbon and/or nitrogen and/or hydrogen. Preferably, the titanium alloy comprises, besides titanium, a proportion of aluminum of 5.5 percent by mass to 6.75 percent by mass, in particular 6 percent by mass, a proportion of vanadium of 3.5 percent by mass to 4.5 percent by mass, in particular 4 percent by mass, and optionally a proportion of iron of 0.4 percent by mass and/or a proportion of oxygen of 0.2 percent by mass and/or a proportion of carbon of 0.08 percent by mass and/or a proportion of nitrogen of 0.05 percent by mass and/or a proportion of hydrogen of 0.015 percent by mass or consists of the aforementioned elements/constituents. In particular, the main body 10 can have a lattice structure, preferably composed of Ti-6Al-4V. With regard to further suitable materials for the main body 10, reference is made to the general description and to the description of FIG. 1.

[0117] Owing to only partial encasing of the main body 10 by the encasing body 20, it is advantageously possible for the thickness of the bone implant 1 to be controlled in an application-oriented manner. Preferably, the nonencased region 12 of the bone implant 1 is intended to receive an extension shaft (not shown) of a joint implant. If the bone implant 1 is a tibial bone implant, the nonencased section 12 is a proximal section of the bone implant. By contrast, if the bone implant 1 is a femoral bone implant, the nonencased section 12 is a distal section of the bone implant.

[0118] With regard to further features and advantages of the bone implant 1, in particular the main body 10 and the encasing body 20, full reference is made to the description of FIG. 1 so as to avoid repetition. The features and advantages described there with regard to the bone implant 1, in particular the main body 10 and the encasing body 20, also apply mutatis mutandis to the bone implant 1 depicted in FIG. 2.

[0119] FIG. 3 shows a further embodiment of a bone implant 1 according to the invention.

[0120] The bone implant system 1 schematically depicted in FIG. 3 comprises a main body 10 and a multiplicity of shaped bodies 20. Six shaped bodies 20 are depicted by way of example. It will be appreciated that the bone implant 1 can, however, also comprise fewer shaped bodies or more shaped bodies.

[0121] The main body 10 is in the form of a conical hollow body open or opened on both sides in the axial direction A.

[0122] The main body 10 comprises a load-bearing material, in particular a titanium alloy, such as, for example, Ti-6Al-4V, or a plastic, in particular polyetheretherketone, or consists of such a material. As a result, sufficient primary and secondary stability is achievable with particular advantage. With regard to further suitable materials for the main body 10, reference is made to the general description and to the description of FIGS. 1 and 2.

[0123] Preferably, the main body 10 comprises a wall 11 having two preferably opposing openings or cutouts 12. The openings or cutouts 12 are preferably U-shaped.

[0124] The shaped bodies 20 comprise an in vivo degradable/in vivo resorbable material or consist of such a material. As a result, biological reconstruction of a bone defect can be achieved with particular advantage. The biological reconstruction of the bone defect advantageously leads to minimization of the size of the bone defect. This in turn reduces the risk of revision surgery and/or creates favorable conditions for successful performance of revision surgery. The in vivo degradable/in vivo resorbable material can, for example, be a calcium phosphate, in particular β-tricalcium phosphate and/or hydroxyapatite. Alternatively, the in vivo degradable/in vivo resorbable material can be a polymer, such as, for example, polycaprolactone, or a metal, such as, for example, magnesium. With regard to further suitable materials for the encasing body 20, reference is made to the general description and to the description of FIGS. 1 and 2.

[0125] The shaped bodies 20 protrude from the main body 10 in the radial direction. The shaped bodies 20 are integrally connected to the main body 10 or integrally joined thereto. For example, the shaped bodies 20 can be adhesively bonded or welded to the main body 10. Alternatively, the shaped bodies 20 can be shaped on the outside, i.e., on an outer face 12 of the main body 10, by means of an additive manufacturing process.

[0126] The shaped bodies 20 are preferably in the form of sheets, in particular in the form of plates or disks. This means that the shaped bodies 20 have a length and a width that are smaller than a thickness (height) of the shaped bodies 20. Preferably, the shaped bodies 20 each have two main faces arranged opposite one another, each of which is delimited by two transverse side faces arranged opposite one another and by two longitudinal side faces arranged opposite one another.

[0127] To improve osteointegration of the bone implant 1, it may further be preferred if the shaped bodies 20 each have a porous, in particular open-pored, and/or microstructured surface or consist of a porous, in particular open-pored, material. With regard to a material that is suitable in this respect, reference is likewise made to the general description and to the description of FIGS. 1 and 2.