A printed metal and polyethylene material integrated knee joint prosthesis and its preparation method

Abstract

The present invention relates to the technical field of medical orthopedic bionic materials, specifically a printed metal and polyethylene integrated knee joint prosthesis and a preparation method. Any one of tantalum, titanium, titanium alloy, zirconium-niobium alloy, and cobalt-chromium alloy is used to print a 3D printed metal component. The 3D printed metal component is integrally formed by 3D printing, and from top to bottom, there are a porous structure 1, a solid structure, and a porous structure 2. The porous structure 2 is combined with the polyethylene component by injection molding or hot pressing. The middle is the solid structure, and the bottom layer is the porous structure 2. The porous structure 2 is combined with the polyethylene. The polymer polyethylene material is ball milled to make the solid powder of the polymer polyethylene after molding more evenly distributed and the gap smaller, thereby improving the mechanical properties and internal wear properties of the material, and avoiding adverse events such as ion poisoning caused by metal wear debris.

Description

Technical Field

[0001] The present invention relates to the technical field of medical orthopedic bionic materials, and specifically to a knee joint prosthesis integrated with printed metal and polyethylene materials and a preparation method thereof. Background Art

[0002] In recent years, with the deepening aging problem both domestically and internationally, the proportion of the elderly population has grown rapidly, and bone and joint diseases are becoming increasingly common. More and more patients are requiring artificial joint replacement surgery, and the number of artificial knee joint surgeries is also on the rise. Currently, the materials used for the tibial side of artificial knee prostheses on the market are metals such as cobalt-chromium alloys, titanium alloys, and tantalum, and polymer materials such as high-molecular polyethylene and polyetheretherketone. The main product forms are either a combination of metal components and polyethylene, i.e., a tibial tray with a polyethylene tibial spacer, or a combination of the entire tibial component and polyethylene. Currently, the tibial components of the knee joint on the market are essentially fixed with bone cement.

[0003] Conventional tibial plateaus are typically composed of a metal tibial tray and a polyethylene tibial spacer. These combination tibial plateaus are locked together through mechanical structural design, which creates a risk of fretting corrosion on the assembly surface, leading to a high incidence of adverse events such as osteolysis. The only one-piece tibial plateau on the market is a fully polyethylene platform, meaning both the friction and fixation interfaces are made of polyethylene. Polyethylene has excellent wear resistance, but requires bone cement fixation, making it difficult to repair. Polyethylene also has relatively poor fixation strength and is prone to deformation after implantation, leading to prosthesis failure.

[0004] In order to solve the above problems and improve the safety performance of knee joint prosthesis during use, the present invention provides a printed metal and polyethylene integrated knee joint prosthesis and a preparation method. Summary of the Invention

[0005] The purpose of the present invention is to provide a printed metal and polyethylene material integrated knee joint prosthesis and a preparation method to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a printed metal and polyethylene material integrated knee joint prosthesis and a preparation method.

[0007] A metal and polyethylene printed metal and polyethylene integrated knee joint prosthesis, the printed metal and polyethylene integrated knee joint prosthesis consisting of a 3D printed metal component and a polyethylene component; the 3D printed metal component is integrally formed by 3D printing, and from bottom to top comprises a porous structure 1, a solid structure, and a porous structure 2; the porous structure 2 is combined with the polyethylene component by injection molding or hot pressing.

[0008] More optimally, the thickness of the porous structure 1 is 0.8mm-8mm, and the porosity is 20%-75%; the thickness of the solid structure is 1mm-2mm; the thickness of the porous structure 2 is 0.15mm-3.5mm, and the porosity is 10%-80%.

[0009] More optimally, when the thickness of the porous structure 2 is 0.15mm-1.5mm, the porosity is 20%-75%; when the thickness of the porous structure 2 is 1.5mm-2.5mm, the porosity is 20%-75%; when the thickness of the porous structure 2 is 2.5mm-3.5mm, the porosity is 25%-80%.

[0010] More optimally, the 3D printed metal component is made of any one of tantalum, titanium, titanium alloy, zirconium-niobium alloy, and cobalt-chromium alloy.

[0011] A method for preparing a printed metal and polyethylene integrated knee joint prosthesis comprises the following steps:

[0012] Step 1: Place polyethylene powder in an ethanol solution, stir under 600-650W ultrasonic conditions for 30-40 minutes, magnetic stirring for 45-50 minutes, continue ultrasonic stirring for 1-2 hours, and heat in a 50°C oil bath until the ethanol is completely volatilized to obtain a polyethylene masterbatch;

[0013] Step 2: Take polyethylene masterbatch, add anhydrous ethanol, ball mill, and dry at 65-70°C to obtain activated polyethylene powder;

[0014] Step 3: Add the activated polyethylene powder into the mold, maintain it at 180-185°C and 15MPa for 30-40 minutes, anneal and cool it to obtain the polyethylene part;

[0015] Step 4: Combine the polyethylene parts with the 3D printed metal parts through injection molding and hot pressing processes to obtain an integrated knee joint prosthesis.

[0016] More optimally, in step 2, during ball milling, the rotation speed is 400-500 r / min, the ball milling time is 50-70 min, and the diameter of the grinding ball is 4 mm.

[0017] More optimally, in step four, the polyethylene component is combined with the 3D printed metal component through injection molding and hot pressing processes, with the injection molding temperature being 140-200°C, the pressure being 50-100 MPa, and the hot pressing temperature being 120°C-200°C.

[0018] More optimally, in step 1, the polyethylene powder is modified ultra-high molecular weight polyethylene; the preparation method of the modified ultra-high molecular weight polyethylene comprises the following steps:

[0019] S1: Take hydroxyapatite powder and anhydrous ethanol, disperse them evenly, add Schiff base-silicon compound and silane coupling agent, heat to 80-85°C, react for 22-26 hours, cool, filter and dry to obtain hydroxyapatite composite;

[0020] S2: taking ultra-high molecular weight polyethylene and hydroxyapatite composite, melt blending at 200-210° C., extruding, cooling, pelletizing, drying, and crushing to obtain modified ultra-high molecular weight polyethylene.

[0021] More optimally, the preparation method of the Schiff base-silicon compound is: take salicylaldehyde, o-phenylenediamine, and ethanol, mix them evenly, heat them to 80-85°C, reflux for 50-70 minutes, cool them for 30-40 minutes, filter, wash, recrystallize, and dry to obtain a Schiff base; take a Schiff base and anhydrous ethanol, stir them evenly to obtain a Schiff base mixed solution; take silicon acetate and anhydrous ethanol, stir them evenly, add the Schiff base mixed solution, reflux for 50-70 minutes, filter, wash, and recrystallize with chloroform to obtain a Schiff base-silicon compound.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention prepares a printed metal and polyethylene material integrated knee joint prosthesis, which is composed of a 3D printed metal component and a polyethylene component. Any one of tantalum, titanium, titanium alloy, zirconium-niobium alloy, and cobalt-chromium alloy is used to print the 3D printed metal component. The 3D printed metal component is integrally formed by 3D printing, and from top to bottom, it is a porous structure 1, a solid structure, and a porous structure 2. The porous structure 2 is combined with the polyethylene component by injection molding or hot pressing. The middle is the solid structure, and the bottom layer is the porous structure 2. The porous structure 2 is combined with the polyethylene component.

[0024] (2) The polymer polyethylene material was ball-milled to make the solid powder distribution of the polymer polyethylene more uniform and the gap smaller after molding, thereby improving the mechanical properties and internal wear resistance of the material. Compared with the ordinary combined tibial plateau prosthesis, the 3D printed metal skeleton and polymer polyethylene material integrated tibial plateau prosthesis eliminates the risk of the tibial gasket being dislodged from the tibial tray, and at the same time avoids the micro-wear caused by human activities after the locking structure of the combined tibial plateau is implanted, and ion poisoning caused by metal wear debris and other adverse events. The 3D printed metal skeleton and polymer polyethylene material integrated tibial plateau can play an effective anti-rotation and fixation function after implantation into the human body by designing columns, triangular wings or triangular nails on the bottom plane.

[0025] (3) Adding a hydroxyapatite composite to ultra-high molecular weight polyethylene (UHMWPE) contains a Schiff base-silicon compound and hydroxyapatite. The addition of hydroxyapatite can reduce the entanglement between UHMWPE molecular chains and reduce the cross-linking density, thereby reducing the viscoelasticity of the melt and facilitating its injection molding process.

[0026] Schiff base-silicon compounds are prepared using silicon acetate and o-phenylenediamine. The addition of Schiff base-silicon compounds can enhance the wear resistance of polyethylene materials. However, the Schiff base-silicon compounds are unevenly dispersed in polyethylene. Grafting the Schiff base-silicon compounds onto hydroxyapatite can also prevent them from agglomerating in the polyethylene material, further enhancing the wear resistance of the polyethylene material. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 This is a schematic diagram of the structure of the metal and polyethylene integrated knee joint prosthesis of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the 3D printed metal component of the present invention;

[0030] Figure 3 It is a schematic diagram of the structure of a blank sample combining metal and polyethylene components of the present invention.

[0031] In the figure: 1-polyethylene component, 2-3D printed metal component, 3-porous structure 1, 4-solid structure, 5-porous structure 2. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] The main reagents used in the present invention are as follows:

[0034] Ultra-high molecular weight polyethylene powder: GUR1050, provided by Ticona Co., Ltd. of the United States.

[0035] Hydroxyapatite powder, item number: S14126, size: provided by Shanghai Yuanye Biotechnology Co., Ltd.

[0036] Silicon acetate: provided by Hubei Hengjingrui Chemical Co., Ltd.

[0037] Example 1:

[0038] Step 1: Place 100g of modified ultra-high molecular weight polyethylene in 200g of 95% ethanol solution, stir under 600W ultrasonic conditions for 30min, magnetic stirring for 45min, and continue ultrasonic stirring for 1.5h. Then heat the mixture in a 50°C oil bath until the ethanol is completely evaporated to obtain a polyethylene masterbatch.

[0039] The polyethylene masterbatch was mechanically activated: 50 g of polyethylene masterbatch was placed in a 400 ml polyamide ball mill, 200 4 mm diameter glass grinding balls and 100 ml of anhydrous ethanol were added, and the ball mill was vertically mounted on a ball mill stand. The rotation speed of the ball mill was 400 r / min, and the ball milling time was 60 min. After the ball milling was completed, the powder was dried at 70 ° C to constant weight to obtain activated polyethylene powder.

[0040] The activated polyethylene powder was added to a mold and maintained at 180°C and 15 MPa for 30 minutes to discharge the gas in the mixed masterbatch and avoid excessive pores in the material. The mold was then annealed at 140°C and 20 MPa for 15 minutes and naturally cooled to 30°C to obtain polyethylene component 1.

[0041] Example 2:

[0042] Step 1: Preparation of modified ultra-high molecular weight polyethylene:

[0043] Take 12 g of salicylaldehyde, 5.8 g of o-phenylenediamine, and 10 mL of ethanol, mix them evenly, heat to 82°C, reflux for 60 min, cool for 35 min, filter, wash, recrystallize, and dry to obtain a Schiff base. Take 10 g of Schiff base and 20 mL of anhydrous ethanol, stir evenly to obtain a Schiff base mixed solution.

[0044] Take 12 g of silicon acetate and 100 mL of anhydrous ethanol, stir evenly, add the Schiff base mixed solution, reflux for 60 minutes, filter, wash, and recrystallize with chloroform to obtain a Schiff base-silicon compound.

[0045] Take 1 g of hydroxyapatite powder and 100 mL of anhydrous ethanol, disperse them evenly, add 0.1 g of Schiff base-silicon compound and 0.2 g of silane coupling agent WD-60, heat to 82°C, react for 26 hours, cool, filter, and dry to obtain a hydroxyapatite composite.

[0046] 100 g of ultra-high molecular weight polyethylene and 30 g of hydroxyapatite composite were melt-blended at 205° C., extruded, cooled, pelletized, dried, and crushed to obtain modified ultra-high molecular weight polyethylene.

[0047] Step 2: Place 100g of modified ultra-high molecular weight polyethylene in 200g of 95% ethanol solution, stir under 600W ultrasonic conditions for 30min, magnetic stirring for 45min, and continue ultrasonic stirring for 1.5h. Then, heat the mixture in a 50°C oil bath until the ethanol is completely evaporated to obtain a polyethylene masterbatch.

[0048] The polyethylene masterbatch was mechanically activated: 50 g of polyethylene masterbatch was placed in a 400 ml polyamide ball mill, 200 4 mm diameter glass grinding balls and 100 ml of anhydrous ethanol were added, and the ball mill was vertically mounted on a ball mill stand. The rotation speed of the ball mill was 400 r / min, and the ball milling time was 60 min. After the ball milling was completed, the powder was dried at 70 ° C to constant weight to obtain activated polyethylene powder.

[0049] The activated polyethylene powder was added to a mold and maintained at 180°C and 15 MPa for 30 minutes to discharge the gas in the mixed masterbatch and avoid excessive pores in the material. The mold was then annealed at 140°C and 20 MPa for 15 minutes and naturally cooled to 30°C to obtain polyethylene component 1.

[0050] Example 3:

[0051] Step 1: Preparation of modified ultra-high molecular weight polyethylene:

[0052] Take 12 g of salicylaldehyde, 5.8 g of o-phenylenediamine, and 10 mL of ethanol, mix well, heat to 80°C, reflux for 50 min, cool for 30 min, filter, wash, recrystallize, and dry to obtain a Schiff base. Take 10 g of Schiff base and 20 mL of anhydrous ethanol, stir well to obtain a Schiff base mixed solution.

[0053] Take 12 g of silicon acetate and 100 mL of anhydrous ethanol, stir evenly, add the Schiff base mixed solution, reflux for 70 minutes, filter, wash, and recrystallize with chloroform to obtain a Schiff base-silicon compound.

[0054] Take 1 g of hydroxyapatite powder and 100 mL of anhydrous ethanol, disperse them evenly, add 0.1 g of Schiff base-silicon compound and 0.2 g of silane coupling agent WD-60, heat to 80°C, react for 22 hours, cool, filter, and dry to obtain a hydroxyapatite composite.

[0055] 100 g of ultra-high molecular weight polyethylene and 30 g of hydroxyapatite composite were melt-blended at 200° C., extruded, cooled, pelletized, dried, and crushed to obtain modified ultra-high molecular weight polyethylene.

[0056] Step 2: Place 100g of modified ultra-high molecular weight polyethylene in 200g of 95% ethanol solution, stir under 600W ultrasonic conditions for 30min, magnetic stirring for 45min, and continue ultrasonic stirring for 1.5h. Then, heat the mixture in a 50°C oil bath until the ethanol is completely evaporated to obtain a polyethylene masterbatch.

[0057] The polyethylene masterbatch was mechanically activated: 50 g of polyethylene masterbatch was placed in a 400 ml polyamide ball mill, 200 4 mm diameter glass grinding balls and 100 ml of anhydrous ethanol were added, and the ball mill was vertically mounted on a ball mill stand. The rotation speed of the ball mill was 400 r / min, and the ball milling time was 60 min. After the ball milling was completed, the powder was dried at 70 ° C to constant weight to obtain activated polyethylene powder.

[0058] The activated polyethylene powder was added to a mold and maintained at 180°C and 15 MPa for 30 minutes to discharge the gas in the mixed masterbatch and avoid excessive pores in the material. The mold was then annealed at 140°C and 20 MPa for 15 minutes and naturally cooled to 30°C to obtain polyethylene component 1.

[0059] Example 4:

[0060] Step 1: Preparation of modified ultra-high molecular weight polyethylene:

[0061] Take 12 g of salicylaldehyde, 5.8 g of o-phenylenediamine, and 10 mL of ethanol, mix well, heat to 85°C, reflux for 50 min, cool for 40 min, filter, wash, recrystallize, and dry to obtain a Schiff base. Take 10 g of Schiff base and 20 mL of anhydrous ethanol, stir well to obtain a Schiff base mixed solution.

[0062] Take 12 g of silicon acetate and 100 mL of anhydrous ethanol, stir evenly, add the Schiff base mixed solution, reflux for 70 minutes, filter, wash, and recrystallize with chloroform to obtain a Schiff base-silicon compound.

[0063] Take 1 g of hydroxyapatite powder and 100 mL of anhydrous ethanol, disperse them evenly, add 0.1 g of Schiff base-silicon compound and 0.2 g of silane coupling agent WD-60, heat to 85°C, react for 26 hours, cool, filter, and dry to obtain a hydroxyapatite composite.

[0064] 100 g of ultra-high molecular weight polyethylene and 30 g of hydroxyapatite composite were melt-blended at 210° C., extruded, cooled, pelletized, dried, and crushed to obtain modified ultra-high molecular weight polyethylene.

[0065] Step 2: Place 100g of modified ultra-high molecular weight polyethylene in 200g of 95% ethanol solution, stir under 600W ultrasonic conditions for 30min, magnetic stirring for 45min, and continue ultrasonic stirring for 1.5h. Then, heat the mixture in a 50°C oil bath until the ethanol is completely evaporated to obtain a polyethylene masterbatch.

[0066] The polyethylene masterbatch was mechanically activated: 50 g of polyethylene masterbatch was placed in a 400 ml polyamide ball mill, 200 4 mm diameter glass grinding balls and 100 ml of anhydrous ethanol were added, and the ball mill was vertically mounted on a ball mill stand. The rotation speed of the ball mill was 400 r / min, and the ball milling time was 60 min. After the ball milling was completed, the powder was dried at 70 ° C to constant weight to obtain activated polyethylene powder.

[0067] The activated polyethylene powder was added to the mold and maintained at 180°C and 15 MPa for 30 minutes to discharge the gas in the mixed masterbatch and avoid excessive pores in the material. The mold was then annealed at 140°C and 20 MPa for 15 minutes and naturally cooled to 30°C to obtain polyethylene component 1.

[0068] Comparative Example 1: No hydroxyapatite was added, and the rest was the same as Example 2.

[0069] Step 1: Preparation of modified ultra-high molecular weight polyethylene:

[0070] Take 12 g of salicylaldehyde, 5.8 g of o-phenylenediamine, and 10 mL of ethanol, mix them evenly, heat to 82°C, reflux for 60 min, cool for 35 min, filter, wash, recrystallize, and dry to obtain a Schiff base. Take 10 g of Schiff base and 20 mL of anhydrous ethanol, stir evenly to obtain a Schiff base mixed solution.

[0071] Take 12 g of silicon acetate and 100 mL of anhydrous ethanol, stir evenly, add the Schiff base mixed solution, reflux for 60 minutes, filter, wash, and recrystallize with chloroform to obtain a Schiff base-silicon compound.

[0072] 100 g of ultra-high molecular weight polyethylene and 30 g of Schiff base-silicon compound were melt-blended at 205° C., extruded, cooled, pelletized, dried, and crushed to obtain modified ultra-high molecular weight polyethylene.

[0073] Step 2: Place 100g of modified ultra-high molecular weight polyethylene in 200g of 95% ethanol solution, stir under 600W ultrasonic conditions for 30min, magnetic stirring for 45min, and continue ultrasonic stirring for 1.5h. Then, heat the mixture in a 50°C oil bath until the ethanol is completely evaporated to obtain a polyethylene masterbatch.

[0074] The polyethylene masterbatch was mechanically activated: 50 g of polyethylene masterbatch was placed in a 400 ml polyamide ball mill, 200 4 mm diameter glass grinding balls and 100 ml of anhydrous ethanol were added, and the ball mill was vertically mounted on a ball mill stand. The rotation speed of the ball mill was 400 r / min, and the ball milling time was 60 min. After the ball milling was completed, the powder was dried at 70 ° C to constant weight to obtain activated polyethylene powder.

[0075] The activated polyethylene powder was added to a mold and maintained at 180°C and 15 MPa for 30 minutes to discharge the gas in the mixed masterbatch and avoid excessive pores in the material. The mold was then annealed at 140°C and 20 MPa for 15 minutes and naturally cooled to 30°C to obtain polyethylene component 1.

[0076] Comparative Example 2: No Schiff base-silicon compound was added, and the rest was the same as Example 2.

[0077] Step 1: Preparation of modified ultra-high molecular weight polyethylene:

[0078] 100 g of ultra-high molecular weight polyethylene and 30 g of hydroxyapatite powder were melt-blended at 205° C., extruded, cooled, pelletized, dried, and crushed to obtain modified ultra-high molecular weight polyethylene.

[0079] Step 2: Place 100g of modified ultra-high molecular weight polyethylene in 200g of 95% ethanol solution, stir under 600W ultrasonic conditions for 30min, magnetic stirring for 45min, and continue ultrasonic stirring for 1.5h. Then, heat the mixture in a 50°C oil bath until the ethanol is completely evaporated to obtain a polyethylene masterbatch.

[0080] The polyethylene masterbatch was mechanically activated: 50 g of polyethylene masterbatch was placed in a 400 ml polyamide ball mill, 200 4 mm diameter glass grinding balls and 100 ml of anhydrous ethanol were added, and the ball mill was vertically mounted on a ball mill stand. The rotation speed of the ball mill was 400 r / min, and the ball milling time was 60 min. After the ball milling was completed, the powder was dried at 70 ° C to constant weight to obtain activated polyethylene powder.

[0081] The activated polyethylene powder was added to a mold and maintained at 180°C and 15 MPa for 30 minutes to discharge the gas in the mixed masterbatch and avoid excessive pores in the material. The mold was then annealed at 140°C and 20 MPa for 15 minutes and naturally cooled to 30°C to obtain polyethylene component 1.

[0082] Example 5: Preparation of an integrated knee joint prosthesis:

[0083] Using titanium alloy, a 3D-printed metal component 2 was produced through electron beam melting. The porous structure 1, numbered 3, was 1.2 mm thick and had a porosity of 35%. The solid structure 4 was 1.5 mm thick. The porous structure 2, numbered 5, was 0.8 mm thick and had a porosity of 55%. The polyethylene component was then combined with the 3D-printed metal component through injection molding and hot pressing to create a one-piece knee prosthesis.

[0084] Example 6: The porous structure 2 has a thickness of 2.0 mm and a porosity of 45%, and the rest is the same as Example 5.

[0085] Example 7: The porous structure 2 has a thickness of 3.5 mm and a porosity of 55%, and the rest is the same as Example 5.

[0086] Comparative Example 3: The porous structure 2 has a thickness of 0.15 mm and a porosity of 65%, and the rest is the same as in Example 5.

[0087] Comparative Example 4: The porous structure 2 has a thickness of 4.5 mm and a porosity of 50%, and the rest is the same as in Example 5.

[0088] Experiment 1:

[0089] The polyethylene parts prepared in Examples 1-4 and Comparative Examples 1-2 were processed into Φ30mm×6mm cylinders with a roughness of 1.7μm; the titanium alloy discs were processed into Φ50mm×6mm cylinders with a roughness of 0.06μm. The titanium alloy discs slid back and forth at a frequency of 1Hz, with a reciprocating stroke of ±5mm, an average sliding speed of 0.02m / s, and a normal load of 50N to test the wear performance. 0.2mL of calf serum solution was dripped between the contact surfaces of the titanium alloy disc and the polyethylene part for lubrication. According to ISO14242-1, calf serum was added to deionized water to prepare a 25vol% calf serum solution by volume. The data obtained are shown in the following table:

[0090] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 <![CDATA[Wear amount / mm 3 > 0.16 0.09 0.09 0.09 0.13 0.15

[0091] Conclusion: In Example 1, the polymer polyethylene material was ball milled. The solid powder of the polymer polyethylene after molding was more evenly distributed, with smaller gaps and a material wear loss of 0.16 mm. 3 In Comparative Example 1, hydroxyapatite was not added, and the Schiff base-silicon compound was unevenly dispersed in the polyethylene, resulting in slightly worse wear resistance than in Examples 2-4. In Comparative Example 2, no Schiff base-silicon compound was added, and the wear loss increased. Therefore, the addition of the Schiff base-silicon compound of the present invention can enhance the wear resistance of the polyethylene material.

[0092] Experiment 2:

[0093] Separation load testing was performed on the printed metal and polyethylene integrated knee prostheses prepared in Examples 5-7 and Comparative Examples 3-4. With the metal components of the integrated knee prostheses fixed, a vertical load was applied to the polyethylene column at the same lever arm, starting at 0 N and increasing until the polyethylene and metal components separated. The resulting data is shown in the table below:

[0094] Example 5 Example 6 Example 7 Comparative Example 3 Comparative Example 4 Combined Depth 1.4mm 2.43mm 3.36mm 0.1mm 3.45mm Separation load 523N 936N 1132N 102N 1205N

[0095] Conclusion: When the thickness of the porous structure 2 is 0.15mm-3mm and the porosity is 10%-70%, the composite performance of the printed metal and polyethylene integrated knee joint prosthesis is optimal.

[0096] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A printed metal and polyethylene integrated knee prosthesis, characterized by: The printed metal and polyethylene material integrated knee joint prosthesis is composed of a polyethylene component (1) and a 3D printed metal component (2); the 3D printed metal component (2) is integrally formed by 3D printing, and comprises, from bottom to top, a porous structure 1 (3), a solid structure (4), and a porous structure 2 (5); the porous structure 2 (5) is combined with the polyethylene component (1) by injection molding or hot pressing; A method for preparing a printed metal and polyethylene integrated knee joint prosthesis comprises the following steps: Step 1: Place polyethylene powder in an ethanol solution, stir under 600-650W ultrasonic conditions for 30-40 minutes, magnetic stirring for 45-50 minutes, continue ultrasonic stirring for 1-2 hours, and heat in a 50°C oil bath until the ethanol is completely volatilized to obtain a polyethylene masterbatch; Step 2: Take polyethylene masterbatch, add anhydrous ethanol, ball mill, and dry at 65-70°C to obtain activated polyethylene powder; Step 3: Add the activated polyethylene powder into a mold, maintain it at 180-185° C. and 15 MPa for 30-40 minutes, anneal it, and cool it to obtain a polyethylene component (1); Step 4: combining the polyethylene component (1) with the 3D printed metal component (2) through injection molding and hot pressing processes to obtain an integrated knee joint prosthesis; In step 1, the polyethylene powder is modified ultra-high molecular weight polyethylene; the preparation method of the modified ultra-high molecular weight polyethylene comprises the following steps: S1: Take hydroxyapatite powder and anhydrous ethanol, disperse them evenly, add Schiff base-silicon compound and silane coupling agent, heat to 80-85°C, react for 22-26 hours, cool, filter and dry to obtain hydroxyapatite composite; S2: taking ultra-high molecular weight polyethylene and hydroxyapatite composite, melt blending at 200-210° C., extruding, cooling, pelletizing, drying, and crushing to obtain modified ultra-high molecular weight polyethylene.

2. The printed metal and polyethylene integrated knee joint prosthesis according to claim 1, characterized in that: The thickness of the porous structure 1 (3) is 0.8mm-8mm, and the porosity is 20%-75%; the thickness of the solid structure (4) is 1mm-2mm; the thickness of the porous structure 2 (5) is 0.15mm-3.5mm, and the porosity is 10%-80%.

3. The printed metal and polyethylene integrated knee joint prosthesis according to claim 2, characterized in that: When the thickness of the porous structure 2 (5) is 0.15mm-1.5mm, the porosity is 20%-75%; when the thickness of the porous structure 2 (5) is 1.5mm-2.5mm, the porosity is 20%-75%; when the thickness of the porous structure 2 (5) is 2.5mm-3.5mm, the porosity is 25%-80%.

4. The printed metal and polyethylene integrated knee joint prosthesis according to claim 1, characterized in that: The material of the 3D printed metal component (2) is any one of tantalum, titanium, titanium alloy, zirconium-niobium alloy, and cobalt-chromium alloy.

5. A method for preparing a printed metal and polyethylene integrated knee joint prosthesis, characterized by: The following steps are involved: Step 1: Place polyethylene powder in an ethanol solution, stir under 600-650W ultrasonic conditions for 30-40 minutes, magnetic stirring for 45-50 minutes, continue ultrasonic stirring for 1-2 hours, and heat in a 50°C oil bath until the ethanol is completely volatilized to obtain a polyethylene masterbatch; Step 2: Take polyethylene masterbatch, add anhydrous ethanol, ball mill, and dry at 65-70°C to obtain activated polyethylene powder; Step 3: Add the activated polyethylene powder into a mold, maintain it at 180-185° C. and 15 MPa for 30-40 minutes, anneal it, and cool it to obtain a polyethylene component (1); Step 4: combining the polyethylene component (1) with the 3D printed metal component (2) through injection molding and hot pressing processes to obtain an integrated knee joint prosthesis; In step 1, the polyethylene powder is modified ultra-high molecular weight polyethylene; the preparation method of the modified ultra-high molecular weight polyethylene comprises the following steps: S1: Take hydroxyapatite powder and anhydrous ethanol, disperse them evenly, add Schiff base-silicon compound and silane coupling agent, heat to 80-85°C, react for 22-26 hours, cool, filter and dry to obtain hydroxyapatite composite; S2: taking ultra-high molecular weight polyethylene and hydroxyapatite composite, melt blending at 200-210° C., extruding, cooling, pelletizing, drying, and crushing to obtain modified ultra-high molecular weight polyethylene.

6. The method for preparing a printed metal and polyethylene integrated knee joint prosthesis according to claim 5, characterized in that: In step 2, during ball milling, the rotation speed is 400-500 r / min, the ball milling time is 50-70 min, and the diameter of the grinding ball is 4 mm.

7. The method for preparing a printed metal and polyethylene integrated knee joint prosthesis according to claim 5, characterized in that: In step 4, the polyethylene component (1) is combined with the 3D printed metal component (2) through injection molding and hot pressing processes, with the injection molding temperature being 140-200°C, the pressure being 50-100 MPa, and the hot pressing temperature being 120-200°C.

8. The method for preparing a printed metal and polyethylene integrated knee joint prosthesis according to claim 5, characterized in that: The preparation method of the Schiff base-silicon compound comprises the following steps: taking salicylaldehyde, o-phenylenediamine, and ethanol, mixing them uniformly, heating them to 80-85° C., refluxing them for 50-70 minutes, cooling them for 30-40 minutes, filtering them with suction, washing them, recrystallizing them, and drying them to obtain a Schiff base; taking the Schiff base and anhydrous ethanol, stirring them uniformly to obtain a Schiff base mixed solution; taking silicon acetate and anhydrous ethanol, stirring them uniformly, adding the Schiff base mixed solution, refluxing them for 50-70 minutes, filtering them with suction, washing them, and recrystallizing them with chloroform to obtain the Schiff base-silicon compound.

Images