Knee joint endoprosthesis and surgical kit for knee joint replacement

Abstract

The invention relates to a knee joint endoprosthesis (1) having a femoral component (10) for anchoring to a distal end of a femur and a tibial component (30) for anchoring to a proximal end of a tibia, wherein the femoral component and the tibial component each have a surface (17, 37) that is porous and / or has elevations and depressions. The invention further relates to a surgical kit for knee joint replacement.

Description

[0001] Knee joint endoprosthesis and surgical kit for knee joint replacement

[0002] SCOPE OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a knee joint endoprosthesis and a surgical kit for knee joint replacement.

[0004] Knee joint endoprostheses are known, for example, from DE 202008 004 709 U1 , DE 102014 106 012 B9 , EP 4 149 395 B1 and EP 3 359 093 B1.

[0005] A fundamental disadvantage of existing endoprostheses is that they are either only suitable for use with or without bone cement. Therefore, an intraoperative change from a cementless to a cemented preparation, or vice versa, is generally not possible.

[0006] TASK AND SOLUTION

[0007] The present invention is based on the objective of providing a knee joint endoprosthesis that allows for a more flexible fixation option for the knee joint endoprosthesis, in particular an intraoperative change from a bone cement-free to a bone cement-containing fixation of the knee joint endoprosthesis or vice versa.

[0008] Furthermore, the invention is based on the objective of providing a suitable surgical kit for knee joint replacement.

[0009] These problems are solved by a knee joint endoprosthesis with the features according to independent claim 1 and by a surgical kit for knee joint replacement according to claim 15. Preferred embodiments of the invention are defined in the dependent claims. The wording of all claims is hereby incorporated by express reference into the content of this description.

[0010] According to a first aspect, the invention relates to a knee joint endoprosthesis.

[0011] Knee joint replacement can be a partial knee joint replacement, i.e., a knee joint replacement for the partial replacement of a knee joint, or a total knee joint replacement, i.e., a knee joint replacement for the complete replacement of a knee joint.

[0012] The knee joint endoprosthesis has a femoral component for anchoring (the femoral component) to a distal end of a femur and a tibial component for anchoring (the tibial component) to a proximal end of a tibia.

[0013] The femoral component has a porous surface, i.e., a surface with pores, especially an open-pored surface, and / or a surface with elevations and depressions, particularly only in certain areas or sections.

[0014] The tibial component also has a porous surface, i.e., a surface with pores, especially open-pored surfaces, and / or raised areas and depressions, particularly only in certain areas or sections.

[0015] The knee joint endoprosthesis can also be referred to as a knee endoprosthesis within the meaning of the present invention.

[0016] For the purposes of this invention, the term "femoral component" refers to an endoprosthesis for fixation to a femur. Within the scope of this invention, the femoral component forms part of the knee joint endoprosthesis according to the invention.

[0017] For the purposes of the present invention, the term "tibial component" refers to an endoprosthesis for fixation to a tibia. Within the scope of the present invention, the tibial component forms part of the knee joint endoprosthesis according to the invention.

[0018] For the purposes of the present invention, the term "femur" shall be understood to mean the thigh bone of a mammal, in particular a human or non-human mammal.

[0019] For the purposes of this invention, the term "tibia" shall be understood to mean the shinbone or lower leg bone of a mammal, in particular a human or non-human mammal. For the purposes of this invention, the term "distal" shall be understood to mean "away from the midline of a patient's body".

[0020] For the purposes of the present invention, the term "proximal" shall be understood to mean "located towards the torso of a patient" or "running towards the torso of a patient".

[0021] For the purposes of the present invention, the term "bone cement material" shall be understood to mean a curable material, in particular a two-component system of solid, in particular powdered solid, and liquid, in particular aqueous liquid, to increase the stability, in particular primary stability, between a knee joint prosthesis surface, in particular surface of a femoral component and / or tibial component, and bone, in particular femur and / or tibia.

[0022] The knee joint endoprosthesis according to the invention is advantageously suitable for the, in particular complete or partial, replacement of a knee joint both in combination with a bone cement material (bone cement-containing preparation) and without the additional use of a bone cement material (bone cement-free preparation). This is made possible by the fact that both the femoral component and the tibial component have a porous surface and / or a surface with raised areas and depressions. This provides, on the one hand, a surface structure that promotes neogenesis and / or the ingrowth of bone tissue and thus secondary stabilization of the femoral component and the tibial component, and therefore of the knee joint endoprosthesis as a whole. On the other hand, the porous surface and / or surface with raised areas and depressions provides a rough surface structure, which improves adhesion and / or...The invention offers fixation options for bone cement materials. This advantageously allows for additional optimization of the primary stabilization of the knee endoprosthesis, should sufficient primary stability not be achievable solely through a clamping effect of the knee endoprosthesis in the bone, for example, due to the quality of the patient's bone tissue. Overall, the knee endoprosthesis according to the invention thus enables – depending on the quality of the patient's bone tissue – a flexible, patient-specific, intraoperative adaptation of the fixation method for the knee endoprosthesis.

[0023] In an embodiment of the invention, the porous surface of the femoral component, which has protrusions and / or depressions, is formed, in particular exclusively, on a proximal side of the femoral component or, in the implanted state of the knee endoprosthesis, on the side facing the femur. In a further embodiment of the invention, the femoral component is designed as a unicondylar femoral component, i.e., the femoral component has only one femoral condyle with one femoral condylar surface, in particular only one medial femoral condyle with a medial femoral condylar surface or only one lateral femoral condyle with a lateral femoral condylar surface.

[0024] In a further embodiment of the invention, the femoral component is designed as a bicondylar femoral component, i.e., the femoral component has a medial femoral condyle with a medial femoral condylar surface and a lateral femoral condyle with a lateral femoral condylar surface.

[0025] In a further embodiment of the invention, the porous and / or raised and recessed surface of the tibial component is formed, in particular exclusively, on a distal side of the tibial component or on the side of the tibial component facing the knee endoprosthesis in the implanted state.

[0026] In a further embodiment of the invention, the porous and / or raised and recessed surface of the femur component and the porous and / or raised and recessed surface of the tibial component are designed identically, particularly with regard to at least one of the features selected from the group consisting of pore diameter, pore shape, pore density, pore connectivity, shape of the raised and recessed features and dimensions, in particular height and / or width and / or length, of the raised and recessed features.

[0027] In a further embodiment of the invention, the porous and / or raised and recessed surface of the femur component and the porous and / or raised and recessed surface of the tibial component are designed differently, in particular with regard to at least one of the features selected from the group consisting of pore diameter, pore shape, pore density, pore connectivity, shape of the raised and recessed features and dimensions, in particular height and / or width and / or length, of the raised and recessed features.

[0028] In a further embodiment of the invention, the porous and / or raised and depression-bearing surface of the femoral component and / or tibial component has, in particular independently of one another or each, interconnected pores, so-called interconnecting pores. Preferably, the interconnected pores form a lattice structure. This particularly promotes the ingrowth of bone tissue. Furthermore, a lattice structure advantageously creates a particularly rough surface, which in turn allows for improved fixation of the knee endoprosthesis using a bone cement material.

[0029] In a further embodiment of the invention, the porous and / or raised and depression-enhanced surface of the femoral component and / or tibial component has, in particular independently of one another or each, pores with a diameter, in particular mean pore diameter, or pores with a cell size, in particular mean cell size, of 0.1 mm to 6 mm, in particular 0.5 mm to 6 mm or 0.1 mm to 1 mm. In the case of pores with a circular circumference, the diameter of the pores, according to the present invention, corresponds to twice the radius of the circular circumference. In the case of non-circular pores, the pore diameter, according to the present invention, corresponds to the greatest possible distance that two points along a pore circumference can be from each other.

[0030] In a further embodiment of the invention, the protrusions and depressions of the porous surface of the femoral component and / or tibial component, particularly independently of one another or individually, form a grid or pattern, especially a waffle pattern. The shape and / or geometry of the protrusions and depressions are not subject to any restrictions in principle, as long as the resulting surface structure possesses a certain roughness to allow adhesion of bone cement materials. For example, the protrusions can be pyramidal, conical, frustoconical, tetrahedral, cylindrical, cubic, cuboidal, or spherical. Furthermore, the protrusions and / or depressions can have a cornerless, in particular oval, elliptical, or circular, or a polygonal, in particular triangular, quadrilateral, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, or decagonal, perimeter.

[0031] In a further embodiment of the invention, the protrusions and depressions of the porous and / or protrusion and depression-bearing surface of the femoral component and / or tibial component have dimensions, in particular independently of each other or each, in particular a height and / or a width and / or a length and / or a cell width, of 0.1 mm to 6 mm, in particular 0.5 mm to 6 mm or 0.1 mm to 1 mm.

[0032] In a further embodiment of the invention, the porous and / or raised and recessed surface of the femur component and / or tibial component, in particular independently of each other or each, has a metal or alloy structure or a polymer structure, or the porous and / or raised and recessed surface of the femur component and / or tibial component, in particular independently of each other or each, is formed by a metal or alloy structure or by a polymer structure.

[0033] For the purposes of the present invention, the term "metal or alloy structure" shall be understood to mean a structure which includes or consists of a metal or an alloy or consists of an alloy.

[0034] For the purposes of the present invention, the term "polymer structure" shall be understood to mean a structure that comprises or consists of a polymer. The polymer may, for example, be polyetheretherketone (PEEK).

[0035] In a further embodiment of the invention, the metal or alloy structure or the polymer structure is inserted into a shape-complementary recess of the femoral component and / or tibial component.

[0036] Preferably, interconnected webs of the metal or alloy structure or the polymer structure form pores of the porous and / or raised and recessed surface and / or a three-dimensional grid.

[0037] Preferably, the metal or alloy structure comprises titanium, a titanium alloy, stainless steel, or a cobalt alloy. Optionally, the metal or alloy structure may be made of one of the aforementioned metals or alloys. The stainless steel may, in particular, be stainless steel according to ISO 5832-1. The titanium alloy may, in particular, be the titanium alloy Ti6Al4V, i.e., an alloy with the following components: 3.5 wt.% to 4.5 wt.% vanadium, 5.5 wt.% to 6.75 wt.% aluminum, the remainder titanium, and optionally unavoidable impurities. In particular, the titanium alloy may be the titanium alloy Ti6Al4V according to ISO 5832-3.

[0038] In a further embodiment of the invention, the metal or alloy structure or the polymer structure is designed as a 3D printed component, i.e. produced by means of 3D printing or additive manufacturing.

[0039] For the purposes of the present invention, the terms "3D printing" or "additive manufacturing" shall be understood to mean a process in which a material, in particular a metal, a hard metal, an alloy, a ceramic, a plastic, a synthetic resin, or a combination of at least two of the aforementioned materials, is applied layer by layer, in particular onto a substrate or support, and three-dimensional objects are thus built up or produced. Preferably, the layer-by-layer construction is computer-controlled from one or more liquid or solid materials according to predetermined dimensions and shapes (CAD and / or CAM). Physical and / or chemical hardening or melting processes may take place during the construction process. The 3D printing or...Additive manufacturing allows, in particular, the creation of complex geometries, flexible production, weight reduction through internal structures, and the possibility of manufacturing small structures.

[0040] Furthermore, the knee joint endoprosthesis may have a meniscus component, in particular a meniscus component located between the femoral component and the tibial component in the implanted state of the knee joint endoprosthesis.

[0041] The meniscus component preferably has at least one bearing shell, in particular two adjacent bearing shells, on a side facing the femoral component of the implanted knee endoprosthesis, into which at least one femoral condyle surface, in particular the lateral or medial femoral condyle surface, or in particular the lateral and medial femoral condyle surfaces, are inserted or received, and a meniscus bearing surface on a side facing the tibial component of the implanted knee endoprosthesis. The meniscus bearing surface is preferably designed to be complementary to a bearing surface of the tibial component, so that when the meniscus component is placed on the tibial component, a complete or substantially full-surface contact is achieved.The meniscus component may comprise a biocompatible polymer, such as polyethylene (PE), in particular ultra-high molecular weight polyethylene (UHMWPE), polyetheretherketone (PEEK), polyaryletherketone (PAEK) or a combination, in particular a blend or composite, of at least two of the aforementioned polymers.

[0042] According to a second aspect, the invention relates to a surgical kit for, in particular partial or total, knee joint replacement.

[0043] The surgical kit comprises a knee endoprosthesis according to the first aspect of the invention and at least one further component. The at least one further component is selected, in particular, from the group consisting of bone cement material, instructions for use, nails, screws, and combinations of at least two of the aforementioned further components. Regarding further features of the surgical kit, in particular the knee endoprosthesis, reference is made to the descriptions given in the context of the first aspect of the invention, which also apply mutatis mutandis to the second aspect of the invention.

[0044] FIGURE DESCRIPTION

[0045] The figures schematically depict the following:

[0046] Fig. 1: an exploded view of an embodiment of a knee joint endoprosthesis according to the present invention,

[0047] Fig. 2: an exploded view of another embodiment of a

[0048] Knee joint endoprosthesis according to the present invention,

[0049] Fig. 3: a close-up of a porous surface of a femoral component of a

[0050] Knee joint endoprosthesis according to the present invention and

[0051] Fig. 4a, b: Detailed views of a surface having elevations and depressions of a tibial component of a knee joint endoprosthesis according to the invention.

[0052] DETAILED CHARACTER DESCRIPTION

[0053] Fig. 1 schematically shows an embodiment of a knee joint endoprosthesis 1 according to the present invention.

[0054] The knee joint endoprosthesis has a femoral component 10 for anchoring to a distal end of a femur and a tibial component 30 for anchoring to a proximal end of a tibia.

[0055] The femoral component 10 has a porous, i.e., having pores, in particular an open-pored, surface 17.

[0056] The tibial component 30 has a porous, i.e., pore-bearing, and in particular open-pored, surface 37. The surfaces 17 and 37 can be identical or different in design. For example, the surfaces 17 and 37 can be identical or different with respect to the diameter of the pores and / or the shape of the pores and / or the density of the pores and / or the connectivity of the pores and / or the shape of the protrusions and depressions and / or the dimensions, in particular height and / or width and / or length, of the protrusions and depressions.

[0057] Preferably, the surface 17 is formed, in particular only, on a side of the femoral component 10 facing the femur in the implanted state of the knee joint endoprosthesis 1.

[0058] Furthermore, the femoral component 10 can have only one femoral condyle, in particular only one medial femoral condyle or only one lateral femoral condyle, 12 with one femoral condylar surface, in particular medial femoral condylar surface or lateral femoral condylar surface 14 (so-called unicondylar femoral component).

[0059] Preferably, the surface 37 is formed, in particular only, on a side of the tibial component 30 facing the tibia in the implanted state of the knee endoprosthesis 1.

[0060] Surfaces 17 and 37 may, in particular independently of each other or each, have interconnecting pores.

[0061] Furthermore, surfaces 17 and 37, in particular independently of each other or each, can have pores with a diameter of 0.1 mm to 6 mm, in particular 0.5 mm to 6 mm or 0.1 mm to 1 mm.

[0062] Preferably, the pores of surfaces 17 and 37 form a lattice-like structure. A lattice-like structure advantageously promotes the neogenesis of bone tissue and / or the ingrowth of bone tissue into the lattice structure, and thus the secondary stability of the knee joint endoprosthesis.

[0063] Surfaces 17 and 37 are formed, in particular independently of each other or each, by a metal or alloy structure or a polymer structure. The metal or alloy structure or polymer structure forming surface 17 can be inserted into a shape-complementary recess of the femoral component 10, and the metal or alloy structure or polymer structure forming surface 37 can be inserted into a shape-complementary recess of the tibial component 30. In particular, interconnected webs of the metal or alloy structure or polymer structure forming surface 17 and / or the metal or alloy structure or polymer structure forming surface 37 can form pores and / or a three-dimensional lattice.

[0064] Furthermore, the metal or alloy structure forming surface 17 and / or surface 37 may be made of titanium, a titanium alloy, stainless steel or a cobalt alloy, or be made of one of the aforementioned metals or alloys.

[0065] Furthermore, the polymer structure forming surface 17 and / or the polymer structure forming surface 37 may contain or be made of polyetheretherketone (PEEK).

[0066] Preferably, the metal or alloy structure or polymer structure forming surface 17 and / or the metal or alloy structure or polymer structure forming surface 37 are designed as 3D-printed components, i.e., produced by means of 3D printing or additive manufacturing. This advantageously allows for the realization of more complex shapes or geometries, which may be required, for example, due to patient-specific conditions.

[0067] Furthermore, the femoral component 10 can, for example, have two shafts 15 and 16 for anchoring to the distal end of the femur.

[0068] The tibial component 30 has a plate 32 with a bearing surface 31. Furthermore, the tibial component 30 has a shaft 35 to anchor the tibial component 30 to the proximal end of the tibia.

[0069] Furthermore, the knee endoprosthesis 1 can have a meniscal component 20. In the implanted state of the knee endoprosthesis 1, the meniscal component 20 is positioned between the femoral component 10 and the tibial component 20. The meniscal component 20 has a bearing surface 21 on a side 21 facing the femoral component 10 in the implanted state of the knee endoprosthesis 1, into which a femoral condylar surface, in particular the lateral or medial femoral condylar surface, 14, is inserted or received, and a meniscal bearing surface 23 on a side facing the tibial component in the implanted state of the knee endoprosthesis. The meniscal bearing surface 23 is designed to be complementary to the bearing surface 31 of the tibial component 30, so that when the meniscal component 20 is placed on the tibial component 30, a complete or substantially full-surface contact is achieved.The meniscus component 20 may comprise a biocompatible polymer, such as polyethylene (PE), in particular ultra-high molecular weight polyethylene (IIHMWPE), polyetheretherketone (PEEK), polyaryletherketone (PAEK) or a combination, in particular a blend or composite, of at least two of the aforementioned polymers.

[0070] Fig. 2 schematically shows another embodiment of a knee joint endoprosthesis 1 according to the present invention.

[0071] In contrast to the knee endoprosthesis 1 according to the invention shown in Fig. 1, the knee endoprosthesis 1 shown in Fig. 2 has a bicondylar femoral component 10, i.e. a femoral component 10 with two femoral condyles 12, 13 and two femoral condylar surfaces 14, 15, namely a medial femoral condyle 12 with a medial femoral condylar surface 14 and a lateral femoral condyle 13 with a lateral

[0072] Femoral condylar surface 15 or vice versa (i.e., a medial femoral condyle 13 with a medial femoral condylar surface 15 and a lateral femoral condyle 12 with a lateral

[0073] Femoral condylar surface 14 on.

[0074] Accordingly, the meniscal component 20 of the one shown in Fig. 2 exhibits

[0075] The knee endoprosthesis 1 has two adjacent bearing shells on a side facing the femoral component 10 in the implanted state of the knee endoprosthesis 1, into which the medial femoral condyle surface 14 and the lateral femoral condyle surface 15 (or the medial femoral condyle surface 15 and the lateral femoral condyle surface 14) are immersed or received.

[0076] Furthermore, the reference numerals in Fig. 2 have the same meaning as the reference numerals in Fig. 1, so that with regard to further features and advantages reference is made to the description of Fig. 1, which also applies analogously to the knee joint endoprosthesis shown in Fig. 2.

[0077] Fig. 3 schematically shows a detailed view of a porous and / or raised and recessed surface 17 of a femoral component of a knee joint endoprosthesis according to the present invention.

[0078] The surface 17 has an open-pore design. This advantageously provides bone cement materials 40 with better adhesion / fixation possibilities. These materials can penetrate, in particular, into the pores 19 of the surface 17 and thus, after hardening, contribute to optimizing the primary stability of the knee endoprosthesis. Preferably, in the implanted state of the knee endoprosthesis, the surface 17 is only formed on one side of the femoral component facing the femur.

[0079] Figures 4a and 4b each show a detailed view of a surface 37 of a tibial component 30 of a knee endoprosthesis according to the invention, which has raised and recessed areas. The raised and recessed areas can have dimensions, in particular a height and / or a width and / or a length and / or a cell size, of 0.1 mm to 6 mm, more specifically 0.5 mm to 6 mm or 0.1 mm to 1 mm. The raised and recessed areas advantageously give the surface 37 a roughness, which results in better adhesion / fixation possibilities for bone substitute materials, should the use of such materials be necessary to improve the primary stability of the knee endoprosthesis. Depending on the arrangement of the raised and recessed areas relative to each other, the surface 37 can, for example, have a lattice-like structure (Fig. 4a) or a patterned, in particular waffle-patterned, structure (Fig. 4b).

Claims

Patent claims 1. Knee joint endoprosthesis with a femoral component for anchoring to a distal end of a femur and a tibial component for anchoring to a proximal end of a tibia, characterized in that the femoral component and the tibial component each have a porous and / or raised and recessed surface.

2. Knee joint endoprosthesis according to claim 1, characterized in that the porous and / or raised and recessed surface of the femoral component is formed, in particular exclusively, on a side of the femoral component facing the femur in the implanted state of the knee joint endoprosthesis.

3. Knee joint endoprosthesis according to claim 1 or 2, characterized in that the femoral component has only one femoral condyle with one femoral condylar surface, in particular only one medial femoral condyle with one medial femoral condylar surface or only one lateral femoral condyle with one lateral femoral condylar surface.

4. Knee joint endoprosthesis according to claim 1 or 2, characterized in that the femoral component has a medial femoral condyle with a medial femoral condylar surface and a lateral femoral condyle with a lateral femoral condylar surface.

5. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the porous and / or raised and recessed surface of the tibial component is formed, in particular exclusively, on a side of the tibial component facing the tibia in the implanted state of the knee joint endoprosthesis.

6. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the porous and / or raised and recessed surface of the femoral component and the porous and / or raised and recessed surface of the tibial component are designed identically.

7. Knee joint endoprosthesis according to one of claims 1 to 5, characterized in that the porous and / or having protrusions and depressions surface of the The femoral component and the porous and / or raised and indented surface of the tibial component are designed differently.

8. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the porous and / or raised and recessed surface has interconnected pores, wherein the interconnected pores preferably form a grid structure.

9. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the porous and / or raised and recessed surface has pores with a diameter of 0.1 mm to 6 mm, in particular 0.1 mm to 1 mm.

10. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the protrusions and depressions form a grid or pattern, in particular a waffle pattern.

11. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the protrusions and depressions have dimensions of 0.1 mm to 6 mm, in particular 0.1 mm to 1 mm.

12. Knee joint endoprosthesis according to one of the preceding claims, characterized in that the porous and / or raised and recessed surface is formed of a metal or alloy structure or polymer structure.

13. Knee joint endoprosthesis according to claim 12, characterized in that the metal or alloy structure or the polymer structure is inserted into a shape-complementary recess of the femoral component and / or tibial component.

14. Knee joint endoprosthesis according to claim 12 or 13, characterized in that the metal or alloy structure or the polymer structure is designed as a 3D printed component, i.e. produced by means of 3D printing or additive manufacturing.

15. Surgical kit for knee joint replacement, comprising a knee joint endoprosthesis according to one of the preceding claims and at least one further component, in particular selected from the group consisting of bone cement material, Instructions for use, nails, screws and combinations of at least two of the aforementioned additional components.

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