3D biological knee joint and preparation method thereof

Abstract

The invention relates to the technical field of medical instruments, in particular to a 3D (three-dimensional) biological knee joint and a preparation method thereof.The 3D biological knee joint comprises a femoral condyle component, a tibia support component, a meniscus component and a patella component; according to the method, individualized knee joint data of a patient is obtained through CT / MRI scanning, reverse modeling is conducted in combination with Mimics software, a precisely-matched prosthesis three-dimensional model is generated, and the success rate is increased; based on specific anatomical features of a patient, adaptability errors of a traditional standardized prosthesis are avoided, operative wounds are reduced, and the initial stability of the prosthesis and a bone interface is improved. According to the invention, through the combination of technological processes such as individualized modeling, gradient functional coating, multi-process printing and post-treatment, the defects of a traditional knee joint prosthesis are overcome, and the properties such as remarkably improved biocompatibility, excellent antibacterial property, optimized mechanical matching property and accurate individualized adaptation are improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a 3D biological knee joint and its preparation method. Background Technology

[0002] The knee joint is an important weight-bearing joint in the human body. Its complex structure consists of components such as the femoral condyle, tibial support, meniscus, and patella working together to support movement and cushion impact.

[0003] Traditional knee prostheses are mostly made of metal or polymer materials, which have the following significant problems:

[0004] Insufficient biocompatibility: Traditional metal surfaces lack a porous structure and have a weak ability to bond with bone tissue, which can easily lead to prosthesis loosening or aseptic inflammation.

[0005] Limitations of antibacterial properties: Conventional materials cannot effectively inhibit bacterial adhesion, resulting in a higher risk of postoperative infection;

[0006] Poor mechanical compatibility: The large difference in elastic modulus between the prosthesis and natural bone may trigger a "stress shielding" effect, leading to bone resorption;

[0007] Personalized adaptation is difficult: standardized prostheses cannot meet the needs of complex anatomical structures, resulting in large surgical trauma and a long recovery period.

[0008] With the development of 3D printing technology, personalized prostheses have become possible. Although existing 3D-printed knee joints attempt to improve osseointegration through porous structures, they also have some problems: the lack of composite coatings with both osteoinductive and antibacterial properties makes it difficult to balance the needs of osteogenic formation and anti-infection; the interlayer bonding strength is insufficient, the surface roughness is not precisely controlled, and the mechanical stability and cell adhesion are affected. Summary of the Invention

[0009] To address the problems existing in the prior art, the present invention provides a 3D biological knee joint and its preparation method.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A 3D bionic knee joint, comprising:

[0012] The femoral condyle component, the main body of which is made of titanium alloy, has a gradient porous bioactive glass coating on its surface. The porosity of the gradient porous bioactive glass coating gradually decreases from 85% near the joint surface to 70% at the distal end along the direction perpendicular to the surface of the component, and the pore size ranges from 100 to 500 μm.

[0013] Tibial support component, the main body of the tibial support component is titanium alloy, and its surface is provided with a porous titanium and nano silver antibacterial composite coating, the porosity of the composite coating is 60-75%, and the pore size is 200-400μm;

[0014] Meniscus component, wherein the meniscus component is a composite material of PEEK and hydrogel;

[0015] Patellar component, the main body of which is made of titanium alloy, and its surface is provided with micropores, the pore diameter of which is 50-150μm;

[0016] The femoral condyle component, tibial support component, meniscus component, and patellar component are interconnected by medical-grade fixation connectors.

[0017] As a further technical solution, the hydrogel is a polyvinyl alcohol hydrogel, which accounts for 20-30% of the mass of the PEEK and hydrogel composite material.

[0018] As a further technical solution, the medical-grade fixing connector is a medical-grade metal pin.

[0019] The method for preparing a 3D biological knee joint includes the following steps:

[0020] Step 1: Data acquisition and modeling. Use CT or MRI equipment to scan the patient's knee joint to obtain three-dimensional data of the knee joint. Import the three-dimensional data into Mimics software and generate a personalized three-dimensional model of the knee joint prosthesis through reverse modeling technology.

[0021] Step 2: Material selection and mixing. Medical-grade Ti6Al4V powder with a particle size of 10-50μm and a purity of ≥99.5% was selected as the titanium alloy matrix material. Gradient porous bioactive glass coating slurry and nano silver antibacterial coating solution were prepared respectively.

[0022] Step 3: 3D printing is performed using an electron beam melting device in an environment with a temperature of 20-25℃ and a humidity of 40-60%.

[0023] For the femoral condyle component, the laser power is set to 200-400W, the scanning speed to 800-1000mm / s, the layer thickness to 20-50μm, and the fill density to 70-80% for printing;

[0024] For the tibial support component, the laser power is set to 200-400W, the scanning speed to 500-600mm / s, the layer thickness to 30-60μm, and the fill density to 60-70% for printing;

[0025] For the meniscus component, a fused deposition modeling process is used, with the printing temperature controlled at 380-400℃, the printing speed at 30-50mm / s, and the layer thickness at 0.1-0.3mm, to print the composite material of PEEK and hydrogel.

[0026] For the patellar component, an electron beam melting device was used, with the electron beam power set to 250-300W, the scanning speed to 500-800mm / s, the layer thickness to 20-40μm, and the fill density to 75-85%.

[0027] Step 4: Post-processing and surface modification: The printed prosthetic part is placed in a vacuum environment for annealing.

[0028] Plasma spraying technology was used, with a mixture of Ar and He gas as the working gas, and the gradient porous bioactive glass coating slurry prepared in step 2 was sprayed onto the surface of the femoral condyle component under a power of 30-50kW. A nano-silver antibacterial coating solution was then sprayed onto the surface of the tibial support component using electrostatic spraying technology, followed by sintering at 300-320℃ for 30-35 minutes. Finally, all components were mechanically polished to achieve a surface roughness Ra≤0.5μm.

[0029] Step 5: Sterilization and packaging. The prepared 3D biological knee joint is sterilized using gamma rays and then sealed and packaged.

[0030] As a further technical solution, the method for preparing the gradient porous bioactive glass coating slurry is as follows:

[0031] 45S5 bioglass, ammonium bicarbonate pore-forming agent with a particle size of 50-150μm, and phosphate solution binder are mixed in a mass ratio of 62-70:24-30:15-20. The mixture is stirred for 50-60 minutes at a temperature of 20-25℃ and a stirring speed of 200-300r / min to form a uniform gradient porous bioactive glass coating slurry.

[0032] As a further technical solution, the phosphate solution binder is a sodium dihydrogen phosphate solution with a concentration of 1.0-2.0 mol / L and a pH value of 6.5-7.5.

[0033] As a further technical solution, the method for preparing the nano-silver antibacterial coating solution is as follows:

[0034] Nano-silver particles with a particle size of 10-30 nm are dispersed in an ethanol solution with a volume concentration of 50-70% and dispersed at a temperature of 20-25℃ using magnetic stirring at a stirring speed of 450-500 r / min for 30-40 min to prepare a nano-silver antibacterial coating solution.

[0035] As a further technical solution, the annealing is performed at 800°C for 2 hours.

[0036] As a further technical solution, in the plasma spraying process, the volume ratio of the Ar and He mixed gas is 2-3:1.

[0037] As a further technical solution, during electrostatic spraying, the spraying voltage is 15-30kV and the spraying distance is 10-20cm.

[0038] As a further technical solution, the sealed packaging uses a double-layer medical-grade plastic film.

[0039] Furthermore, nitrogen gas is filled inside the packaging to prevent oxidation.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] This invention acquires individualized knee joint data from patients through CT / MRI scans, and uses Mimics software for reverse modeling to generate a precisely fitted 3D model of the prosthesis, thereby improving the success rate. Based on the patient's specific anatomical characteristics, it avoids the fitting errors of traditional standardized prostheses, reduces surgical trauma, and improves the initial stability of the prosthesis-bone interface.

[0042] This invention introduces a gradient porous bioactive glass coating. The porosity of the coating on the femoral condyle surface decreases from 85% at the articular surface to 70% at the distal end, with a pore size of 100-500 μm, promoting the layered growth of chondrocytes and osteocytes. The gradient porosity mimics the structural characteristics of natural subchondral bone, with large pores facilitating chondrocyte adhesion and small pores enhancing bone tissue ingrowth. The 45S5 bioglass releases calcium and phosphorus ions to induce hydroxyapatite deposition, improving bone integration efficiency.

[0043] This invention introduces a porous titanium and nano-silver antibacterial composite coating; the porous titanium structure on the tibial support surface is combined with nano-silver to take into account both bone ingrowth and antibacterial properties; the porous titanium provides mechanical support and bone conduction pathway, while the nano-silver destroys bacterial cell membranes by releasing silver ions, inhibiting the adhesion of pathogenic bacteria such as Staphylococcus aureus, and reducing the risk of postoperative infection.

[0044] In multi-process 3D printing, annealing in post-processing and surface modification eliminates printing stress, improves the fatigue strength of the titanium alloy matrix, and reduces the risk of fracture during long-term use. Ion spraying and electrostatic spraying ensure uniform adhesion of the gradient porous coating and the nano-silver coating, significantly improving bonding strength. A high-temperature plasma flow formed by an Ar / He mixed gas melts the bio-glass slurry and embeds it into the micropores of the titanium alloy surface; electrostatic spraying achieves directional deposition of nano-silver particles, ensuring uniform distribution of antibacterial components.

[0045] This invention addresses the shortcomings of traditional knee joint prostheses by combining individualized modeling, gradient functional coating, multi-process printing, and post-processing, thereby improving performance in areas such as significantly enhanced biocompatibility, superior antibacterial properties, optimized mechanical matching, and precise personalized fit.

[0046] Instruction manual illustrations

[0047] Figure 1 This is a statistical chart of cell survival rates in each experimental group. Detailed Implementation

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] This invention provides a 3D bio-knee joint, comprising: a femoral condyle component, the main body of which is a titanium alloy, and its surface is coated with a gradient porous bioactive glass coating. The porosity of the gradient porous bioactive glass coating gradually decreases from 85% near the joint surface to 70% distally along a direction perpendicular to the component surface, with a pore size range of 100-500 μm; a tibial support component, the main body of which is a titanium alloy, and its surface is coated with a porous titanium and nano-silver antibacterial composite coating. The porosity of the composite coating is 60-75%, and the pore size is 200-400 μm; a meniscus component, the meniscus component being a composite material of PEEK and hydrogel; and a patellar component, the main body of which is a titanium alloy, and its surface is provided with micropores with a pore size of 50-150 μm. The femoral condyle component, tibial support component, meniscus component, and patellar component are interconnected by medical-grade fixation connectors.

[0050] In this invention, the hydrogel is preferably a polyvinyl alcohol hydrogel, and its mass percentage in the PEEK and hydrogel composite material is preferably 20-30%.

[0051] In this invention, the medical-grade fixing connector is preferably a medical-grade metal pin.

[0052] This invention also provides a method for preparing a 3D biological knee joint, comprising the following steps:

[0053] Step 1: Data acquisition and modeling. Use CT or MRI equipment to scan the patient's knee joint to obtain three-dimensional data of the knee joint. Import the three-dimensional data into Mimics software and generate a personalized three-dimensional model of the knee joint prosthesis through reverse modeling technology.

[0054] Step 2: Material selection and mixing. Medical-grade Ti6Al4V powder with a particle size of 10-50μm and a purity of ≥99.5% was selected as the titanium alloy matrix material. Gradient porous bioactive glass coating slurry and nano silver antibacterial coating solution were prepared respectively.

[0055] Step 3: 3D printing is performed using an electron beam melting system in an environment with a temperature of 20-25℃ and a humidity of 40-60%. For the femoral condyle component, the laser power is set to 200-400W, the scanning speed to 800-1000mm / s, the layer thickness to 20-50μm, and the infill density to 70-80%. For the tibial support component, the laser power is set to 200-400W, the scanning speed to 500-600mm / s, and the layer thickness to 30-60μm. Printing is performed with a fill density of 60-70%. For the meniscus component, a fused deposition modeling process is used, with the printing temperature controlled at 380-400℃, the printing speed at 30-50mm / s, and the layer thickness at 0.1-0.3mm, to print the PEEK and hydrogel composite material. For the patella component, an electron beam melting device is used, with the electron beam power set at 250-300W, the scanning speed at 500-800mm / s, the layer thickness at 20-40μm, and the fill density at 75-85%.

[0056] Step 4: Post-processing and surface modification. The printed prosthetic parts are placed in a vacuum environment for annealing. Using plasma spraying technology with a mixture of Ar and He as the working gas, the gradient porous bioactive glass coating slurry prepared in Step 2 is sprayed onto the surface of the femoral condyle part at a power of 30-50kW. The nano-silver antibacterial coating solution is sprayed onto the surface of the tibial support part using electrostatic spraying technology, and then sintered at 300-320℃ for 30-35 minutes. Finally, all parts are mechanically polished to achieve a surface roughness Ra≤0.5μm.

[0057] Step 5: Sterilization and packaging. The prepared 3D biological knee joint is sterilized using gamma rays and then sealed in packaging.

[0058] In this invention, the preferred method for preparing the gradient porous bioactive glass coating slurry is as follows: 45S5 bioglass, ammonium bicarbonate pore-forming agent with a particle size of 50-150μm, and phosphate solution binder are mixed in a mass ratio of 62-70:24-30:15-20, and stirred for 50-60 minutes at a temperature of 20-25℃ and a stirring speed of 200-300r / min to form a uniform gradient porous bioactive glass coating slurry.

[0059] In this invention, the phosphate solution binder is preferably a sodium dihydrogen phosphate solution with a concentration of 1.0-2.0 mol / L and a pH value of 6.5-7.5.

[0060] In this invention, the preferred method for preparing the nano-silver antibacterial coating solution is as follows: nano-silver particles with a particle size of 10-30 nm are dispersed in an ethanol solution with a volume concentration of 50-70%, and the dispersion is carried out at a temperature of 20-25°C using magnetic stirring at a stirring speed of 450-500 r / min for 30-40 min to prepare the nano-silver antibacterial coating solution.

[0061] In this invention, the annealing is preferably performed at 800°C for 2 hours.

[0062] In this invention, during the plasma spraying process, the volume ratio of the Ar and He mixed gas is preferably 2-3:1.

[0063] In this invention, during electrostatic spraying, the spraying voltage is preferably 15-30kV, and the spraying distance is preferably 10-20cm.

[0064] In this invention, the sealed packaging preferably uses a double-layer medical-grade plastic film, and nitrogen is filled inside the packaging to prevent oxidation.

[0065] The 3D bio-knee joint provided by this invention, through the selection of materials and structural design of each component, as well as a specific preparation method, can achieve good biocompatibility, mechanical properties and antibacterial properties.

[0066] To further illustrate the present invention, detailed descriptions are provided below through the following embodiments and comparative examples. Unless otherwise specified, all materials used in the following embodiments and comparative examples are commercially available.

[0067] Example 1

[0068] Data acquisition and modeling: The patient's knee joint was scanned using a CT scanner to obtain three-dimensional data, which was then imported into Mimics software to generate a personalized three-dimensional model of the knee joint prosthesis.

[0069] Material selection and mixing: Medical-grade Ti6Al4V powder with a particle size of 20 μm and a purity of ≥99.5% was selected; a gradient porous bioactive glass coating slurry was prepared by mixing 45S5 bioglass, ammonium bicarbonate pore-forming agent with a particle size of 80 μm, and sodium dihydrogen phosphate solution with a concentration of 1.5 mol / L (pH = 7.0) at a mass ratio of 65:26:18 and stirring at 23℃ and 250 r / min for 55 min; a nano-silver antibacterial coating solution was prepared by dispersing nano-silver particles with a particle size of 20 nm in a 60% ethanol solution at 23℃ and 480 r / min for 35 min.

[0070] 3D printing of the following components: femoral condyle component (laser power 250W, scanning speed 900mm / s, layer thickness 30μm, infill density 75%); tibial condyle component (laser power 250W, scanning speed 550mm / s, layer thickness 40μm, infill density 65%); meniscus component (printing temperature 390℃, printing speed 40mm / s, layer thickness 0.2mm, printed using a PEEK and polyvinyl alcohol hydrogel (25% by mass) composite material); patella component (electron beam power 270W, scanning speed 650mm / s, layer thickness 30μm, infill density 80%).

[0071] Post-treatment and surface modification: annealing at 800℃ in vacuum environment for 2 hours; plasma spraying with Ar and He volume ratio of 2.5:1 and power of 40kW to spray coating slurry; electrostatic spraying with nano silver solution at voltage of 20kV and distance of 15cm, sintering at 310℃ for 33 minutes, and mechanical polishing to Ra≤0.5μm.

[0072] Sterilization and Packaging: Sterilized with gamma rays, packaged in double-layer medical plastic film, and filled with nitrogen gas inside.

[0073] Example 2

[0074] The difference from Example 1 is as follows:

[0075] Material selection and mixing: Ti6Al4V powder with a particle size of 30μm; in the gradient porous bioactive glass coating slurry, the mass ratio of 45S5 bioglass, ammonium bicarbonate pore-forming agent, and sodium dihydrogen phosphate solution is 68:25:17, and the stirring conditions are the same as in Example 1; in the nano silver antibacterial coating solution, the ethanol volume concentration is 55%, and the dispersion conditions are the same as in Example 1.

[0076] 3D printing of the following components: femoral condyle component (300W laser power, 850mm / s scanning speed, 40μm layer thickness, 78% infill density); tibial support component (300W laser power, 580mm / s scanning speed, 50μm layer thickness, 68% infill density); meniscus component (385℃ printing temperature, 35mm / s printing speed, 0.15mm layer thickness, 22% hydrogel mass percentage); patella component (280W electron beam power, 700mm / s scanning speed, 35μm layer thickness, 83% infill density).

[0077] Example 3

[0078] The difference from Example 1 is as follows:

[0079] Material selection and mixing: Ti6Al4V powder with a particle size of 40μm; in the gradient porous bioactive glass coating slurry, the mass ratio of 45S5 bioglass, ammonium bicarbonate pore-forming agent, and sodium dihydrogen phosphate solution is 62:30:18, and the stirring conditions are the same as in Example 1; in the nano silver antibacterial coating solution, the ethanol volume concentration is 70%, and the dispersion conditions are the same as in Example 1.

[0080] 3D printing of the following components: femoral condyle component (laser power 200W, scanning speed 1000mm / s, layer thickness 20μm, infill density 70%); tibial support component (laser power 200W, scanning speed 600mm / s, layer thickness 30μm, infill density 60%); meniscus component (printing temperature 400℃, printing speed 30mm / s, layer thickness 0.3mm, hydrogel mass percentage 30%); patella component (electron beam power 250W, scanning speed 800mm / s, layer thickness 20μm, infill density 75%).

[0081] Example 4

[0082] The difference from Example 1 is as follows:

[0083] Material selection and mixing: Ti6Al4V powder with a particle size of 10μm; in the gradient porous bioactive glass coating slurry, the mass ratio of 45S5 bioglass, ammonium bicarbonate pore-forming agent, and sodium dihydrogen phosphate solution is 70:24:16, and the stirring conditions are the same as in Example 1; in the nano silver antibacterial coating solution, the ethanol volume concentration is 50%, and the dispersion conditions are the same as in Example 1.

[0084] 3D printing of the following components: femoral condyle component (laser power 400W, scanning speed 800mm / s, layer thickness 50μm, infill density 80%); tibial support component (laser power 400W, scanning speed 500mm / s, layer thickness 60μm, infill density 70%); meniscus component (printing temperature 380℃, printing speed 50mm / s, layer thickness 0.1mm, hydrogel mass percentage 20%); patella component (electron beam power 300W, scanning speed 500mm / s, layer thickness 40μm, infill density 85%).

[0085] Example 5

[0086] The difference from Example 1 is as follows:

[0087] Material selection and mixing: Ti6Al4V powder with a particle size of 50μm; in the gradient porous bioactive glass coating slurry, the mass ratio of 45S5 bioglass, ammonium bicarbonate pore-forming agent, and sodium dihydrogen phosphate solution is 66:27:17, and the stirring conditions are the same as in Example 1; in the nano silver antibacterial coating solution, the ethanol volume concentration is 65%, and the dispersion conditions are the same as in Example 1.

[0088] 3D printing results: Femoral condyle component (laser power 350W, scanning speed 950mm / s, layer thickness 35μm, infill density 77%); Tibial support component (laser power 350W, scanning speed 520mm / s, layer thickness 45μm, infill density 63%); Meniscus component (printing temperature 395℃, printing speed 45mm / s, layer thickness 0.25mm, hydrogel mass percentage 28%); Patellar component (electron beam power 290W, scanning speed 750mm / s, layer thickness 38μm, infill density 84%).

[0089] Comparative Example 1

[0090] The difference from Example 1 is that the surface of the femoral condyle component is not coated with a gradient porous bioactive glass coating, while the other conditions are the same as in Example 1.

[0091] Comparative Example 2

[0092] The difference from Example 1 is that the tibial support component does not have a porous titanium and nano-silver antibacterial composite coating on its surface, while the other conditions are the same as in Example 1.

[0093] test

[0094] Cell compatibility assay (refer to GB / T16886.5-2017)

[0095] Experimental methods: The knee joint component materials of Examples 1-5 and Comparative Examples 1-2 were prepared into extracts, inoculated into L929 cells, and cultured for 24 h. The cell viability was determined by the MTT assay.

[0096] Table 1:

[0097]

[0098]

[0099] As can be seen from Table 1, the knee joint prepared by the present invention has high cell compatibility.

[0100] Antibacterial performance test (refer to GB / T20944.3-2008)

[0101] Experimental method: Staphylococcus aureus was used as the test bacteria. The tibial support component samples of Examples 1-5 and Comparative Examples 1-2 were contacted with the bacterial solution and cultured for 24 hours. The antibacterial rate was then calculated.

[0102] Table 2:

[0103]

[0104]

[0105] As can be seen from Table 2, the knee joint prepared by the present invention has excellent antibacterial properties.

[0106] Mechanical property testing (refer to ISO 14879-1:2007)

[0107] Experimental method: Three-point bending tests were performed on the femoral condyle components of Examples 1-5 to determine the bending strength.

[0108] Table 3:

[0109] sample Bending strength (MPa) Example 1 280 Example 2 275 Example 3 270 Example 4 285 Example 5 278

[0110] As can be seen from Table 3, the knee joint prepared by the present invention has excellent mechanical properties.

[0111] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not describe all details exhaustively, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification.

Claims

1. A 3D bionic knee joint, characterized in that, include: The femoral condyle component, the main body of which is made of titanium alloy, has a gradient porous bioactive glass coating on its surface. The porosity of the gradient porous bioactive glass coating gradually decreases from 85% near the joint surface to 70% at the distal end along the direction perpendicular to the surface of the component, and the pore size ranges from 100 to 500 μm. Tibial support component, the main body of the tibial support component is titanium alloy, and its surface is provided with a porous titanium and nano silver antibacterial composite coating, the porosity of the composite coating is 60-75%, and the pore size is 200-400μm; Meniscus component, wherein the meniscus component is a composite material of PEEK and hydrogel; Patellar component, the main body of which is made of titanium alloy, and its surface is provided with micropores, the pore diameter of which is 50-150μm; The femoral condyle component, tibial support component, meniscus component, and patellar component are interconnected by medical-grade fixation connectors.

2. The 3D bio-knee joint according to claim 1, characterized in that, The hydrogel is a polyvinyl alcohol hydrogel, which accounts for 20-30% of the mass of the PEEK and hydrogel composite material.

3. The 3D bio-knee joint according to claim 1, characterized in that, The medical-grade fixing connector is a medical-grade metal pin.

4. The method for preparing a 3D biological knee joint according to claim 1, characterized in that, Includes the following steps: Step 1: Data acquisition and modeling. Use CT or MRI equipment to scan the patient's knee joint to obtain three-dimensional data of the knee joint. Import the three-dimensional data into Mimics software and generate a personalized three-dimensional model of the knee joint prosthesis through reverse modeling technology. Step 2: Material selection and mixing. Medical-grade Ti6Al4V powder with a particle size of 10-50μm and a purity of ≥99.5% was selected as the titanium alloy matrix material. Gradient porous bioactive glass coating slurry and nano silver antibacterial coating solution were prepared respectively. Step 3: 3D printing is performed using an electron beam melting device in an environment with a temperature of 20-25℃ and a humidity of 40-60%. For the femoral condyle component, the laser power is set to 200-400W, the scanning speed to 800-1000mm / s, the layer thickness to 20-50μm, and the fill density to 70-80% for printing; For the tibial support component, the laser power is set to 200-400W, the scanning speed to 500-600mm / s, the layer thickness to 30-60μm, and the fill density to 60-70% for printing; For the meniscus component, a fused deposition modeling process is used, with the printing temperature controlled at 380-400℃, the printing speed at 30-50mm / s, and the layer thickness at 0.1-0.3mm, to print the composite material of PEEK and hydrogel. For the patellar component, an electron beam melting device was used, with the electron beam power set to 250-300W, the scanning speed to 500-800mm / s, the layer thickness to 20-40μm, and the fill density to 75-85%. Step 4: Post-processing and surface modification. The printed prosthetic part is placed in a vacuum environment for annealing. Plasma spraying technology was used, with a mixture of Ar and He gas as the working gas, and the gradient porous bioactive glass coating slurry prepared in step 2 was sprayed onto the surface of the femoral condyle component under a power of 30-50kW. A nano-silver antibacterial coating solution was then sprayed onto the surface of the tibial support component using electrostatic spraying technology, followed by sintering at 300-320℃ for 30-35 minutes. Finally, all components were mechanically polished to achieve a surface roughness Ra≤0.5μm. Step 5: Sterilization and packaging. The prepared 3D biological knee joint is sterilized using gamma rays and then sealed and packaged.

5. The preparation method according to claim 4, characterized in that, The method for preparing the gradient porous bioactive glass coating slurry is as follows: 45S5 bioglass, ammonium bicarbonate pore-forming agent with a particle size of 50-150μm, and phosphate solution binder are mixed in a mass ratio of 62-70:24-30:15-20. The mixture is stirred for 50-60 minutes at a temperature of 20-25℃ and a stirring speed of 200-300r / min to form a uniform gradient porous bioactive glass coating slurry.

6. The preparation method according to claim 5, characterized in that, The phosphate solution binder is a sodium dihydrogen phosphate solution with a concentration of 1.0-2.0 mol / L and a pH value of 6.5-7.

5.

7. The preparation method according to claim 4, characterized in that, The method for preparing the nano-silver antibacterial coating solution is as follows: Nano-silver particles with a particle size of 10-30 nm are dispersed in an ethanol solution with a volume concentration of 50-70% and dispersed at a temperature of 20-25℃ using magnetic stirring at a stirring speed of 450-500 r / min for 30-40 min to prepare a nano-silver antibacterial coating solution.

8. The preparation method according to claim 4, characterized in that, The annealing was performed at 800°C for 2 hours.

9. The preparation method according to claim 4, characterized in that, During the plasma spraying process, the volume ratio of the Ar and He mixed gas is 2-3:

1.

10. The preparation method according to claim 4, characterized in that, During electrostatic spraying, the spraying voltage is 15-30kV and the spraying distance is 10-20cm; the sealed packaging uses double-layer medical-grade plastic film and is filled with nitrogen gas inside the packaging to prevent oxidation.

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