Metal additive manufactured high-wear-resistance heterogeneous femoral condyle prosthesis and manufacturing method thereof

Abstract

The invention discloses a metal additive manufactured high-wear-resistance heterogeneous femoral condyle prosthesis and a manufacturing method thereof, the prosthesis comprises a first plane, a second plane, a third plane and a fourth plane, and the planes are arranged according to bony anatomical features of the distal femur of a patient and are integrally formed; each plane comprises a fine grain layer, a tough base body layer and a mechanical matching porous contact layer, the mechanical matching porous contact layer is in contact with the wound surface of the distal femur, the tough base body layer and the mechanical matching porous contact layer are integrated, the fine grain layer is arranged on the outermost layer, and the mechanical matching porous contact layer is of a porous structure; the second plane is provided with a fixing nail used for fixing a prosthesis on the second plane. The laser in-situ remelting technology is used for acting on the motion curved surface of the prosthesis, the metal structure on the surface of the prosthesis is rapidly condensed to form grain refinement, and therefore the surface performance of the knee joint prosthesis is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and particularly relates to a highly wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing and a manufacturing method thereof. Background Art

[0002] Osteoarthritis is a common degenerative joint disease in middle-aged and elderly people. For different symptoms, the treatment methods are also different. For patients in the late stage of osteoarthritis, joint replacement is required to reduce pain.

[0003] The existing artificial joints for replacement are mainly manufactured by traditional machining methods such as casting. Therefore, it is difficult to achieve personalized precision medicine for the formed implant, and at the same time, the solid metal matrix has stress shielding due to the mismatch of elastic modulus. Stress shielding will cause the implant to loosen, resulting in the failure of the implant. Thanks to the development of 3D printing, the elastic modulus of the implant can be effectively reduced through the design of a porous structure, so it has begun to be widely used.

[0004] Therefore, it is necessary to design a highly wear-resistant knee joint prosthesis with a low modulus and solve various problems existing in the existing knee joint prosthesis through an effective manufacturing method. Summary of the Invention

[0005] The main object of the present invention is to overcome the shortcomings and deficiencies of the existing technology, and provide a highly wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing and a manufacturing method thereof. By using the laser in-situ remelting technology to act on the moving surface of the prosthesis, the metal tissue on the surface of the prosthesis quickly condenses to form refined grains, thereby improving the surface performance of the knee joint prosthesis.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a highly wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing, including: a highly wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing, characterized in that it includes: a first plane, a second plane, a third plane, and a fourth plane, and each plane is arranged and integrally formed along the bony anatomical features of the distal femur of the patient; each plane includes a fine grain layer, a strong and tough matrix layer, and a mechanically matched porous contact layer, the mechanically matched porous contact layer contacts the wound surface of the distal femur, the strong and tough matrix layer is integrated with the mechanically matched porous contact layer, the fine grain layer is arranged on the outermost layer, and the mechanically matched porous contact layer has a porous structure; the second plane is provided with fixing nails for fixing the prosthesis on the second plane.

[0007] As a preferred technical solution, the strong and tough matrix layer is in a "y" shape, including an arch mechanism and a bifurcated mechanism, the arch mechanism extends from the third plane to the fourth plane, and the bifurcated mechanism includes extending from the second plane to the first plane.

[0008] As a preferred technical solution, the porous structure is disposed around the arch mechanism and the bifurcation mechanism and extends to the edge of the prosthesis.

[0009] As a preferred technical solution, the first plane is provided with support beams for supporting the bifurcation mechanism.

[0010] As a preferred technical solution, the thickness of the fine grain layer is greater than 200 microns and the average grain size is less than 50 microns.

[0011] As a preferred technical solution, the porous structure is a random hexagonal porous structure.

[0012] In a second aspect, the present invention provides a manufacturing method of a highly wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing, which is applied to a highly wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing, and includes the following steps: Obtain medical image data of the patient's knee joint, use three-dimensional reconstruction software to obtain a three-dimensional model of the distal femur, and perform surface reverse reconstruction to obtain an editable NURBS surface model of the distal femur; Use the surgical knee replacement femoral osteotomy method to process the editable NURBS surface model of the distal femur, obtain the osteotomy of each part of the distal femur, measure the mechanical properties of the osteotomy according to the osteotomy density, and design a matching porous structure to obtain a mechanically matching porous contact layer model; According to the bony anatomical characteristics of the distal femur and the movement characteristics of the knee joint, perform adaptive arrangement on each plane of the prosthesis to obtain a highly wear-resistant heterogeneous femoral condyle prosthesis model; Slice the highly wear-resistant heterogeneous femoral condyle prosthesis model, import it into selective laser melting for metal forming to obtain a prosthesis prototype, and put the prosthesis prototype into a heat treatment furnace for solution heat treatment and low-temperature annealing treatment to obtain a prosthesis with a strong and tough matrix layer and a mechanically matching porous contact layer; Remelt the moving surface of the prosthesis to form a fine grain layer to obtain a highly wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing.

[0013] As a preferred technical solution, the solution heat treatment includes: putting the prosthesis prototype into a heat treatment furnace and heating it from room temperature to between 1000°C and 1250°C at 5-10°C / min, and taking it out after holding for 60 minutes in this temperature range, and performing water cooling treatment on the prosthesis prototype after solution heat treatment; During the heating process, seal the prosthesis prototype with a quartz tube filled with argon or fill argon into the heat treatment furnace.

[0014] As a preferred technical solution, the low-temperature annealing treatment includes: heating the prosthesis prototype from room temperature to between 300°C and 450°C at a rate of 5-10°C / min, holding it for 30 minutes in the corresponding temperature range, and then taking it out and performing water cooling treatment; during the heating process, the prosthesis prototype is sealed with a quartz tube filled with argon or argon is filled into the heat treatment furnace.

[0015] As a preferred technical solution, the remelting treatment of the moving surface of the prosthesis is specifically: performing laser remelting in-situ regulation treatment on the moving surface of the prosthesis, and the thickness of the in-situ regulated fine grain layer after remelting is greater than 200 microns, and the average grain size is less than 50 microns.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) For the high-wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing in the present invention, the laser in-situ remelting technology is utilized, and high-energy laser is used to act on the moving curved surface of the prosthesis. Through the rapid melting and solidification of the metal tissue on the prosthesis surface, the grain refinement of the prosthesis surface is realized, thereby improving the surface performance of the knee joint prosthesis.

[0017] (2) The manufacturing method of the present invention combines solution heat treatment and low-temperature annealing treatment, and utilizes the input of thermal field energy to promote the recrystallization of the grains of the knee joint prosthesis manufactured by metal additive manufacturing, thereby reducing the anisotropy of the knee joint prosthesis caused by metal additive manufacturing and improving the performance of the prosthesis; at the same time, through low-temperature annealing treatment, stress removal can be achieved, the performance of the prosthesis can be improved, and thus the service time of the prosthesis can be extended.

[0018] (3) By adopting the design based on the bony characteristics of the native bone at the bone contact surface of the prosthesis, the present invention can achieve the mechanical property matching between the knee joint prosthesis and the native bone. At the same time, the design of the porous structure can effectively reduce the mass of the joint prosthesis, increase the contact surface with the native bone, and is beneficial to the bone ingrowth after the prosthesis is implanted. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a structural diagram of the high-wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing in the embodiment of the present invention; Figure 2 It is a grain diagram of the matrix and the fine grain layer in the embodiment of the present invention; Figure 3 It is a flowchart of the manufacturing method of the high-wear-resistant heterogeneous femoral condyle prosthesis manufactured by metal additive manufacturing in the embodiment of the present invention.

[0021] Description of the reference numerals in the drawings: 1. Fine grain layer; 2. Tough matrix layer; 3. Mechanics-matched porous contact layer; 4. Fixing nail; a. First plane; b. Second plane; c. Third plane; d. Fourth plane. Specific implementation manners

[0022] In order to enable those skilled in the art of the present technology to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.

[0023] When "embodiment" is mentioned in this application, it means that the specific features, structures or characteristics described in combination with the embodiment may be included in at least one embodiment of this application. The appearance of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0024] Embodiment 1.

[0025] Please refer to Figure 1 , this embodiment provides a highly wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing, including: a first plane a, a second plane b, a third plane c, and a fourth plane d, and each plane is arranged along the bony anatomical features of the distal femur of the patient and integrally formed; each plane includes a fine grain layer 1, a tough matrix layer 2, and a mechanics-matched porous contact layer 3, the mechanics-matched porous contact layer 3 contacts the wound surface of the distal femur, the tough matrix layer 2 and the mechanics-matched porous contact layer 3 are integrated, the fine grain layer 1 is arranged on the outermost layer, and the mechanics-matched porous contact layer 3 has a porous structure; the second plane b is provided with a fixing nail 4 for fixing the prosthesis on the second plane b.

[0026] Among them, in this embodiment, it is necessary to adaptively design a prosthesis structure that matches the distal femur according to the internal and external anatomical structures of the distal femur of the patient and the movement characteristics of knee joint movement. The prosthesis in this embodiment adopts four-direction planes to adapt to the femoral condyle, and along the internal and external anatomical structures of the distal femur, multiple planes of the prosthesis form an enclosing structure.

[0027] It should be explained that these planes are named for the convenience of describing the structure of this embodiment. In fact, these "planes" are of an integrated design, and for each plane, they are not flat but have a multi-layer structure.

[0028] Refer again to Figure 1 and Figure 2 wherein Figure 2 on the right side in are the grains of the fine-grained layer 1, and on the left side are the grains of the tough and strong matrix layer 2. The prosthesis of this embodiment includes a fine-grained layer 1, a tough and strong matrix layer 2, and a mechanically matching porous contact layer 3. Among them, the fine-grained layer 1 is obtained by in-situ regulating the grain layer thickness of the moving surface of the knee joint prosthesis through laser remelting on the basis of a metal additive manufacturing knee joint prosthesis, and finally a fine-grained layer with a layer thickness greater than 200 microns and an average grain size less than 50 microns is obtained; for the tough and strong matrix layer 2 and the mechanically property-matching porous contact layer 3, they are designed according to the bony anatomical characteristics of the distal femur of the patient. The tough and strong matrix layer 2 and the mechanically property-matching porous contact layer 3 are integrally formed by metal additive manufacturing technology, and through solution heat treatment and low-temperature annealing treatment, the anisotropy of laser additive manufacturing cobalt-chromium-molybdenum and the residual stress of the prosthesis after forming are reduced, thereby improving the mechanical properties and fatigue properties of the prosthesis. For the above solution heat treatment and low-temperature annealing treatment, see Embodiment 2 for details.

[0029] Specifically, the tough and strong matrix layer 2 of this embodiment is in a "y" shape and includes an arch mechanism and a bifurcated mechanism. The arch mechanism extends from the third plane to the fourth plane, and the bifurcated mechanism includes extending from the second plane to the first plane.

[0030] Furthermore, the porous structure is arranged around the arch mechanism and the bifurcated mechanism and extends to the edge of the prosthesis.

[0031] Furthermore, the first plane is provided with support beams for supporting the bifurcated mechanism.

[0032] Specifically, the porous structure adopts a random hexagonal porous structure.

[0033] Embodiment 2.

[0034] Please refer to Figure 3 , this embodiment provides a manufacturing method of a highly wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing, including the following steps: S1. Obtain the medical image data of the patient's knee joint, use three-dimensional reconstruction software to obtain the three-dimensional model of the distal femur, and perform surface reverse reconstruction to obtain an editable NURBS surface model of the distal femur.

[0035] Use a CT or MRI device to collect images of the patient's knee joint to obtain the medical image data of the patient's knee joint. Use this medical image data of the patient's knee joint to construct a model in three-dimensional reconstruction software, and then perform reverse engineering on the surface to reconstruct the characteristics of the distal femur, and finally obtain an editable NURBS surface model of the distal femur.

[0036] S2. Use the femoral osteotomy method for surgical knee replacement to process the editable NURBS surface model of the distal femur, obtain the osteotomy of each part of the distal femur, measure the mechanical properties of the osteotomy according to the osteotomy density, and design a matching porous structure to obtain a porous contact layer model with matching mechanical properties.

[0037] S3. According to the bony anatomical characteristics of the distal femur and the movement characteristics of the knee joint, arrange the prosthesis adaptively in each plane to obtain a highly wear-resistant heterogeneous femoral condyle prosthesis model.

[0038] S4. Slice the highly wear-resistant heterogeneous femoral condyle prosthesis model and import it into selective laser melting of metal to obtain a prosthesis prototype. Put the prosthesis prototype into a heat treatment furnace for solution heat treatment and low-temperature annealing treatment to obtain a prosthesis with a strong and tough matrix layer and a mechanically matched porous contact layer.

[0039] Step S4 is the process of metal additive manufacturing and forming of the prosthesis, which can be specifically divided into metal additive manufacturing, solution heat treatment, and low-temperature annealing treatment.

[0040] S41. Metal additive manufacturing: Obtain the printed prosthesis prototype through selective laser melting of metal and precise plastic forming. S42. Solution heat treatment: Put the prosthesis prototype into a heat treatment furnace and heat it from room temperature to between 1000°C and 1250°C at a rate of 5 - 10°C / min, and keep it at this temperature range for 60 minutes and then take it out. Quench the prosthesis prototype after solution heat treatment. S43. Low-temperature annealing treatment: Heat the prosthesis prototype from room temperature to between 300°C and 450°C at a rate of 5 - 10°C / min, keep it at the corresponding temperature range for 30 minutes and then take it out, and quench it.

[0041] For the heating process in steps S42 - S43, in this embodiment, the sample is sealed with a quartz tube filled with argon or argon is filled into the heat treatment furnace to prevent the sample from being oxidized.

[0042] S5. Remelt the moving surface of the prosthesis to form a fine grain layer to obtain a metal additive manufacturing highly wear-resistant heterogeneous femoral condyle prosthesis.

[0043] Specifically, perform laser remelting in-situ regulation treatment on the moving surface of the prosthesis. The thickness of the in-situ regulated fine grain layer after remelting is greater than 200 microns, and the average grain size is less than 50 microns.

[0044] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope described in this specification.

[0045] The above embodiments are preferred embodiments of the present invention. However, the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A high-wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing, characterized in that, Comprising: A first plane, a second plane, a third plane, and a fourth plane, each plane being arranged along the bony anatomical features of the distal femur of a patient and integrally formed; each plane includes a fine-grained layer, a tough matrix layer, and a mechanically-matched porous contact layer, the mechanically-matched porous contact layer contacting the wound surface of the distal femur, the tough matrix layer being integrated with the mechanically-matched porous contact layer, the fine-grained layer being provided on the outermost layer, and the mechanically-matched porous contact layer having a porous structure; the second plane is provided with fixing pins for fixing the prosthesis on the second plane.

2. The high-wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing according to claim 1, wherein The tough matrix layer is in a "y" shape and includes an arch mechanism and a bifurcated mechanism, the arch mechanism extending from the third plane to the fourth plane, and the bifurcated mechanism including extending from the second plane to the first plane.

3. The high-wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing according to claim 2, characterized in that, The porous structure is arranged around the arch mechanism and the bifurcated mechanism and extends to the edge of the prosthesis.

4. The high-wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing according to claim 2, characterized in that The first plane is provided with a support beam for supporting the bifurcated mechanism.

5. The high-wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing according to claim 1, characterized in that, The thickness of the fine-grained layer is greater than 200 microns, and the average grain size is less than 50 microns.

6. The high wear-resistant heterogeneous femoral condyle prosthesis for metal additive manufacturing according to claim 1, characterized in that The porous structure is a random hexagonal porous structure.

7. A manufacturing method of a highly wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing, characterized in that, Applied to the metal additive manufacturing highly wear-resistant heterogeneous femoral condyle prosthesis according to any one of claims 1-6, comprising the following steps: Obtain the medical imaging data of the patient's knee joint, use 3D reconstruction software to obtain the three-dimensional model of the distal femur, and perform surface reverse reconstruction to obtain an editable NURBS surface model of the distal femur; Use the surgical knee replacement femoral osteotomy method to process the editable NURBS surface model of the distal femur, obtain the osteotomies of various parts of the distal femur, measure the mechanical properties of the osteotomies according to the osteotomy density, and design a matching porous structure to obtain a mechanically-matched porous contact layer model; According to the bony anatomical features of the distal femur and the movement characteristics of the knee joint, arrange each plane of the prosthesis adaptively to obtain a highly wear-resistant heterogeneous femoral condyle prosthesis model; Slice the highly wear-resistant heterogeneous femoral condyle prosthesis model, import it into selective laser melting for metal forming to obtain a prosthesis prototype, and put the prosthesis prototype into a heat treatment furnace for solution heat treatment and low-temperature annealing treatment to obtain a prosthesis with a tough matrix layer and a mechanically-matched porous contact layer; Remelt the moving surface of the prosthesis to form a fine-grained layer to obtain a metal additive manufacturing highly wear-resistant heterogeneous femoral condyle prosthesis.

8. The manufacturing method of the high wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing according to claim 7, characterized in that, The solution heat treatment includes: putting the prosthesis prototype into a heat treatment furnace and heating it from room temperature to between 1000°C and 1250°C at a rate of 5-10°C / min, holding it for 60 minutes in this temperature range and then taking it out, and performing water cooling treatment on the prosthesis prototype after solution heat treatment; During the heating process, seal the prosthesis prototype with a quartz tube filled with argon or fill the heat treatment furnace with argon.

9. The manufacturing method of the high-wear-resistant heterogeneous femoral condyle prosthesis by metal additive manufacturing according to claim 7, characterized in that, The low-temperature annealing treatment includes: heating the prosthesis prototype from room temperature to between 300°C and 450°C at a rate of 5-10°C / min, holding it for 30 minutes in the corresponding temperature range and then taking it out, and performing water cooling treatment; during the heating process, seal the prosthesis prototype with a quartz tube filled with argon or fill the heat treatment furnace with argon.

10. The manufacturing method of the metal additive manufacturing high wear-resistant heterogeneous femoral condyle prosthesis according to claim 7, wherein, The remelting treatment of the moving surface of the prosthesis is specifically as follows: the moving surface of the prosthesis is subjected to laser remelting in-situ regulation treatment, and the thickness of the remelted in-situ regulated fine crystal layer is greater than 200 microns, and the average grain size is less than 50 microns.

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