Knee prosthesis

Abstract

The present application relates to the technical field of medical devices, and discloses a knee joint prosthesis, which comprises a trabecular bone type, one side of the trabecular bone type is provided with a front condyle side, the other side of the trabecular bone type is provided with a notch, both ends of the trabecular bone type notch are provided with distal end sides, the upper surface of the distal end side is provided with a trabecular column, one side of the distal end side is provided with a rear condyle side, the side wall of the trabecular bone type is provided with a femoral condyle body, the inside of the trabecular column is provided with a column, one side of the rear condyle side is provided with a femoral component surface, and the outer wall of the femoral component surface is provided with. The femoral side prosthesis realizes better fusion of the femoral side prosthesis and bone tissue, promotes bone ingrowth, and achieves the effect of long-term stable fixation. The problems of poor long-term stability, easy loosening and easy wear of the friction interface of the traditional femoral side prosthesis are solved, and the service life of the prosthesis and the life quality of the patient are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a knee joint prosthesis. BACKGROUND

[0002] In knee replacement surgery, achieving bone ingrowth of the bone contact interface of the prosthesis to achieve long-term stability is a key goal to ensure surgical effectiveness and patient quality of life. Currently, knee joint prostheses used in clinical applications have many challenges in this regard.

[0003] Traditional cemented knee joint prostheses are widely used. In the early stage of implantation, they can provide good short-term stability by mechanical anchoring of bone cement with bone tissue, allowing patients to perform moderate activities in the short term after surgery. However, over time, problems gradually emerge. As a foreign body, bone cement can trigger a series of biological reactions in the body, leading to a decrease in the bonding strength of the bone cement-bone tissue interface. At the same time, the stress generated by human activity continuously acts on the prosthesis, bone cement, and bone tissue interface, causing fatigue wear and micro-crack propagation of the bone cement, making the prosthesis prone to loosening and sinking during long-term use, and unable to maintain stable bone contact, which seriously affects the service life of the prosthesis and the long-term effectiveness of the patient. SUMMARY

[0004] To overcome the shortcomings of the prior art, the present application provides a knee joint prosthesis, which solves the problem of poor long-term stability of traditional femoral prostheses.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: a knee joint prosthesis, comprising a trabecular bone type, one side of the trabecular bone type is provided with a front condyle side, the other side of the trabecular bone type is provided with a notch, both ends of the trabecular bone type notch are provided with a distal end side, the upper surface of the distal end side is provided with a trabecular bone column, one side of the distal end side is provided with a posterior condyle side, the side wall of the trabecular bone type is provided with a femoral condyle body, the inside of the trabecular bone column is provided with a column, one side of the posterior condyle side is provided with a femoral component surface, the outer wall of the femoral component surface is provided, the upper surface is provided with a tibial platform, one side of the tibial platform is provided with a trabecular bone platform layer, the middle part of the tibial platform is provided with a fixed wing, one side of the trabecular bone platform layer is provided with a plurality of fixed nails, the middle part of the trabecular bone platform layer is provided with a Y-shaped groove, and the Y-shaped groove of the trabecular bone platform layer is symmetrically provided with a trabecular bone reinforcing block.

[0006] Preferably, the trabecular bone type and the trabecular bone column are made of 3D printed titanium alloy powder, the trabecular bone type and the trabecular bone column are subjected to 920℃ hot isostatic pressing at 100Mpa and 800℃ annealing treatment, and the trabecular bone type and the trabecular bone column are used for fixing the prosthesis.

[0007] Preferably, the femoral condyle body and the column are made of 3D printed titanium alloy powder, the femoral condyle body is used as the base of the femoral side, the femoral condyle body and the trabecular interior type are combined, the femoral condyle body and the trabecular interior type are fixed, the column and the trabecular column are connected, and the column and the trabecular column are fixed.

[0008] Preferably, the material of the femoral component surface is made of 3D printed titanium alloy powder, the femoral component surface is coated with an alumina-based coating, the coating thickness can reach 100-250 μm, and the femoral component surface improves the friction interface hardness and wear resistance.

[0009] Preferably, the tibial platform and the fixation nail are made of 3D printed titanium alloy powder, the tibial platform is used as the base of the tibial side, the tibial platform and the trabecular platform layer are combined, the tibial platform and the trabecular platform layer are fixed, the fixation nail has a cross shape, the trabecular platform layer is used for short-term fixation, the trabecular platform layer and the tibial platform are used for the fixation support of the tibial platform, the fixation wing has longitudinal texture, the fixation wing is used for short-term fixation, the trabecular reinforcing block is used for the bone ingrowth of the fixation wing, the trabecular reinforcing block is made of mixed vitamin E high crosslinking, the trabecular reinforcing block is connected with the tibial platform, and the trabecular reinforcing block is used for the friction interface of the femoral component surface.

[0010] Preferably, a method for preparing a tibial pad of a knee joint prosthesis comprises the following steps:

[0011] S1, raw material selection, titanium alloy powder is used, and good fluidity and uniform particle size distribution are required;

[0012] S2, 3D printing forming, a precise three-dimensional model is constructed by means of CAD, and the titanium alloy powder is melted and solidified layer by layer to form according to the set parameters by using electron beam 3D printing technology;

[0013] S3, hot isostatic pressing treatment, the printed part is placed in a hot isostatic pressing device, and the density and performance are improved under the condition of 920 DEG C and 100 Mpa;

[0014] S4, annealing treatment, annealing at 800 DEG C, eliminating residual stress, optimizing crystal structure, and enhancing comprehensive performance.

[0015] Preferably, the material preparation in S1 includes the following steps: titanium alloy powder is selected as the raw material for manufacturing the femoral condyle body, the powder should have good fluidity and uniform particle size distribution to ensure uniform spreading in the 3D printing process, guarantee the printing precision and quality, and lay a foundation for forming a stable structure subsequently.

[0016] Preferably, the 3D printing forming in S2 includes the following steps:

[0017] S201, using computer aided design (CAD) technology, according to the physiological structure of the femoral condyle, the mechanical properties and the overall design standard of the knee prosthesis, the three-dimensional model of the femoral condyle body is accurately constructed;

[0018] S202, using electron beam 3D printing technology, the selected titanium alloy powder is uniformly spread on the printing platform, the electron beam is focused on the powder layer, and the powder is melted and solidified layer by layer according to the preset scanning path and energy parameters.

[0019] Preferably, the S3 hot isostatic pressing treatment includes the following steps: the printed femoral condyle body is placed in the hot isostatic pressing equipment, and the high temperature of 920 DEG C and the high pressure of 100 Mpa are treated for a period of time. The micro-pores and defects in the femoral condyle body are compacted and repaired, the material density is greatly improved, and the internal organization is more uniform.

[0020] Preferably, the S4 annealing treatment includes the following steps: after the hot isostatic pressing treatment is completed, the femoral condyle body is annealed by heating to 800 DEG C and maintaining for a period of time, and then slowly cooling, eliminating the residual stress generated in the 3D printing and hot isostatic pressing process, optimizing the crystal structure of the material, and further improving the comprehensive performance.

[0021] Working principle: select titanium alloy powder with good fluidity and uniform particle size distribution. Good fluidity ensures that the powder can be uniformly spread during 3D printing, and uniform particle size distribution ensures that the powder has consistent melting and solidification behavior, laying a foundation for subsequent stable structure. For example, the titanium alloy powder used to make the femoral condyle body has high precision and good quality.

[0022] In terms of structural design, the femoral side and the tibial side have unique structures. The trabecular intracolumnar type and the trabecular columnar column of the femoral side form an irregular network structure, which cooperates with components such as the femoral condyle body. The trabecular intracolumnar type is fixed in the sagittal plane and the transverse plane, and the trabecular columnar column is fixed in the coronal plane and the sagittal plane, which promotes bone ingrowth and enhances long-term stability. The tibial platform of the tibial side is combined with the trabecular platform layer, the fixed wing and the cross-shaped fixed nail realize short-term fixation, and the trabecular reinforcing block promotes bone ingrowth at the fixed wing.

[0023] In terms of processing technology, computer-aided design (CAD) technology is first used to construct a three-dimensional model based on human physiological structure, mechanical performance requirements, and overall design standards. Then, electron beam 3D printing technology is used to melt and solidify titanium alloy powder layer by layer. Afterward, the printed parts undergo hot isostatic pressing (HIP) at 920℃ and 100MPa to compact pores, repair defects, and improve material density and uniformity. Finally, annealing is performed by heating to 800℃ and holding for a certain time followed by slow cooling to eliminate residual stress, optimize crystal structure, and improve overall performance. Furthermore, the femoral component surface is coated with a 100-250μm alumina-based coating to enhance the hardness and wear resistance of the friction interface; the tibial pad is made of highly cross-linked material mixed with vitamin E to reduce wear rate.

[0024] This invention provides a knee joint prosthesis. It has the following beneficial effects:

[0025] 1. This invention achieves better integration between the femoral prosthesis and bone tissue through the femoral side prosthesis, promoting bone ingrowth and achieving long-term stable fixation. It solves the problems of poor long-term stability, easy loosening, and easy wear at the friction interface of traditional femoral side prostheses, thus improving the prosthesis's lifespan and the patient's quality of life.

[0026] 2. This invention, through the constructed femoral prosthesis structure, enables the femoral prosthesis to better adapt to various mechanical loads generated during human movement, evenly distributing stress and avoiding prosthesis damage or loosening caused by stress concentration. Simultaneously, the use of titanium alloy material achieves a lightweight design of the prosthesis, reducing the burden on the patient's limb and improving post-implantation adaptability.

[0027] 3. This invention improves wear resistance, reduces wear rate, reduces friction debris, lowers the risk of inflammatory response, enhances the hardness of the femoral side friction interface, and improves wear performance by using an alumina-based ceramic coating. At the same time, good biocompatibility reduces the body's rejection reaction to the prosthesis, ensures smooth knee joint movement, and improves the service life of the prosthesis.

[0028] 4. The high precision of 3D printing ensures that the dimensional and shape accuracy of the femoral condyle body meets design requirements, reducing errors and defects during the printing process. The printed femoral condyle body is of superior quality, with a dense and uniform internal structure and excellent mechanical properties. After being combined with other components such as the trabecular bone, the stability of the entire femoral prosthesis is greatly improved, and it can better withstand various stresses generated during human movement. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of a knee joint prosthesis proposed in this invention;

[0030] Figure 2This is a schematic diagram of a partial structure of the femoral condyle of a knee joint prosthesis proposed in this invention;

[0031] Figure 3 This is a schematic diagram of a partial structure of the tibial plateau of a knee joint prosthesis proposed in this invention;

[0032] Figure 4 This is a schematic diagram of a partial structure of the trabecular plateau layer of a knee joint prosthesis proposed in this invention;

[0033] Figure 5 This is a schematic diagram of a partial structure of the tibial pad of a knee joint prosthesis proposed in this invention.

[0034] Among them, 110, intratrabecular shape; 120, trabecular column; 130, femoral condyle body; 140, column; 150, anterior condylar side; 160, distal side; 170, posterior condylar side; 180, femoral component surface; 210, tibial plateau; 220, fixation wing; 230, fixation screw; 240, trabecular plateau layer; 250, trabecular reinforcement block; 30, tibial pad. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. 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.

[0036] Please see the appendix Figure 1 -Appendix Figure 5 A knee joint prosthesis includes an intratrabecular shape 110, with an anterior condylar side 150 on one side and a notch on the other side. Distal sides 160 are located at both ends of the notch. Trabecular posts 120 are disposed on the upper surface of the distal side 160, and a posterior condylar side 170 is disposed on one side of the distal side 160. A femoral condyle body 130 is disposed on the sidewall of the intratrabecular shape 110. Posts 140 are disposed within the trabecular posts 120. The posterior condylar side 170... One side of the femoral component surface 180 is provided, the outer wall of the femoral component surface 180 is provided with a tibial pad 30, the upper surface of the tibial pad 30 is provided with a tibial plateau 210, one side of the tibial plateau 210 is provided with a trabecular plateau layer 240, the middle of the tibial plateau 210 is provided with a fixation wing 220, one side of the trabecular plateau layer 240 is provided with several fixation nails 230, the middle of the trabecular plateau layer 240 is provided with a Y-shaped groove, and trabecular reinforcing blocks 250 are symmetrically arranged in the Y-shaped groove of the trabecular plateau layer 240.

[0037] Specifically, the trabecular mold 110 and trabecular columns 120 are both made of 3D-printed titanium alloy powder and subjected to hot isostatic pressing at 920℃ for 100 MPa and annealing at 800℃. This treatment gives them high strength and a suitable microstructure. The trabecular mold 110 has an irregular mesh structure, connecting with the anterior condylar side 150, the distal side 160, and the posterior condylar side 170, forming a stable support in the sagittal and transverse planes; the trabecular columns 120 further strengthen the fixation in the coronal and sagittal planes. The femoral condyle body 130, as the femoral lateral base, is tightly integrated with the trabecular mold 110, and the columns 140 are connected to the trabecular columns 120, together forming a stable mechanical structure. The femoral component surface 180 is coated with a 100-250μm alumina-based coating, which enhances the hardness of the friction interface and improves wear resistance. The tibial plateau 210, made of 3D-printed titanium alloy powder, serves as the tibial side matrix and is tightly integrated with the trabecular plateau layer 240, providing stable support for the tibia. The fixation wings 220 have longitudinal textures, and the fixation pins 230 are cross-shaped. In the early stages of prosthesis implantation, the two work together to achieve short-term fixation and prevent prosthesis displacement. The trabecular plateau layer 240 not only assists in fixation, but its special structure also creates conditions for bone ingrowth, enhancing long-term stability. The trabecular reinforcement block 250, located in the Y-shaped groove in the middle of the trabecular plateau layer 240, further promotes bone ingrowth at the fixation wings 220, optimizing the fixation effect. The tibial pad 30, made of highly cross-linked material mixed with vitamin E, connects to the tibial plateau 210 and forms a friction interface with the femoral component surface 180, effectively reducing the wear rate and improving wear resistance.

[0038] The femoral lateral prosthesis achieves better integration with bone tissue, promotes bone ingrowth, and results in long-term stable fixation. This solves the problems of poor long-term stability, easy loosening, and easy wear at the friction interface associated with traditional femoral lateral prostheses, thus improving prosthesis lifespan and patients' quality of life.

[0039] See appendix Figure 1 -Appendix Figure 5The trabecular mold 110 and trabecular posts 120 are made of 3D-printed titanium alloy powder. The trabecular mold 110 and trabecular posts 120 undergo hot isostatic pressing at 920℃ for 100 MPa and annealing at 800℃. The trabecular mold 110 and trabecular posts 120 are used for prosthesis fixation. The femoral condyle body 130 and posts 140 are also made of 3D-printed titanium alloy powder. The femoral condyle body 130 serves as the base on the femoral side. The trabecular internal shape 110 is combined with the femoral condyle body 130 and the trabecular internal shape 110, and the column 140 is connected to the trabecular column 120 and fixed to the trabecular column 120. The femoral component surface 180 is made of 3D printed titanium alloy powder, and the surface of the femoral component surface 180 is coated with an alumina-based coating with a coating thickness of 100-250μm. The femoral component surface 180 improves the hardness and wear resistance of the friction interface.

[0040] Specifically, the trabecular internal model 110 and trabecular columns 120 are made of 3D-printed titanium alloy powder. This manufacturing method can precisely shape an irregular mesh structure, giving it microstructural characteristics similar to human bone tissue. Subsequently, they undergo hot isostatic pressing at 920℃ for 100 MPa and annealing at 800℃. During hot isostatic pressing, the high temperature and high pressure environment compacts the tiny pores inside the titanium alloy, resulting in a denser and more uniform structure. Annealing eliminates residual stress generated during printing and hot isostatic pressing, optimizing the crystal structure. In the prosthesis, the trabecular mesh 110, with its irregular mesh structure, forms a complex mechanical anchorage with the surrounding bone tissue in the sagittal and transverse planes of the prosthesis, increasing friction and gripping force. The trabecular columns 120 further enhance this anchorage in the coronal and sagittal planes. The two work together to enhance the connection between the prosthesis and bone tissue from multiple dimensions. Both the femoral condyle body 130 and the columns 140 are made of 3D-printed titanium alloy powder, ensuring material consistency and structural precision. The femoral condyle body 130, as the base of the femoral side, provides the main support structure for the entire femoral side prosthesis. It is combined and fixed with the trabecular mesh 110 through a specific structural design. The irregular mesh structure of the trabecular mesh 110 is embedded in the corresponding part of the femoral condyle body 130 to achieve mechanical locking and integrated connection. The support column 140 is connected and fixed to the trabecular support column 120. Building upon the multi-planar fixation provided by the trabecular support column 120, the support column 140 further enhances the overall structural stability, dispersing and transmitting stress from human movement, ensuring the prosthesis remains stable even under complex stress conditions. The femoral component surface 180 is made of 3D-printed titanium alloy powder, ensuring material compatibility and structural integrity with other parts of the prosthesis. On this basis, an alumina-based coating with a thickness of 100-250 μm is applied to the surface. The alumina-based coating possesses high hardness, good wear resistance, and biocompatibility. During prosthesis use, this coating acts as a friction interface, interacting with relatively moving components (such as the tibial pad 30). The high-hardness coating effectively resists wear during friction, reducing material loss; simultaneously, the coating's microstructure and composition help reduce the coefficient of friction, making joint movement smoother.

[0041] The specially designed femoral prosthesis structure allows it to better adapt to various mechanical loads generated during human movement, evenly distributing stress and preventing prosthesis damage or loosening caused by stress concentration. Simultaneously, the use of titanium alloy enables a lightweight design, reducing the burden on the patient's limb and improving post-implantation adaptability.

[0042] See appendix Figure 3 Appendix Figure 5The tibial plateau 210 and fixation pin 230 are made of 3D printed titanium alloy powder. The tibial plateau 210 is used as the matrix on the tibial side. The tibial plateau 210 and the trabecular plateau layer 240 are combined and fixed together. The fixation pin 230 is cross-shaped. The trabecular plateau layer 240 is used for short-term fixation. The trabecular plateau layer 240 and the tibial plateau 210 are used for fixation support of the tibial plateau. The fixation wing 220 has a longitudinal texture and is used for short-term fixation. The trabecular reinforcement block 250 is used to fix the bone ingrowth of the fixation wing 220. The tibial pad 30 is made of highly cross-linked material mixed with vitamin E. The tibial pad 30 is connected to the tibial plateau 210 and is used as the friction interface on the surface 180 of the femoral component.

[0043] Specifically, the tibial plateau 210 and fixation screw 230 are made of 3D-printed titanium alloy powder, which allows them to have precise shapes and microstructures. The tibial plateau 210, as the base on the tibial side, is tightly integrated and fixed with the trabecular plateau layer 240. The trabecular plateau layer 240 has a special structure; in the early stages of prosthesis implantation, it can initially integrate with surrounding tissues through its own structure, achieving short-term fixation. Simultaneously, it and the tibial plateau 210 together provide stable fixation support for the tibia. The fixation screw 230 is cross-shaped; this design increases the contact area and anchoring force with bone tissue. During implantation, the fixation screw 230 is inserted into the bone tissue, pulling the tibial plateau 210 and trabecular plateau layer 240 from multiple directions to prevent displacement. The fixation wings 220 have longitudinal textures; during surgical implantation, these textures increase friction with surrounding bone tissue, quickly fixing the tibial plateau 210 locally and providing short-term fixation. The trabecular reinforcement block 250 is located near the fixation wing 220, creating favorable conditions for bone ingrowth at the fixation wing 220. The trabecular reinforcement block 250 has a porous structure, similar to human trabeculae, which guides bone cell growth within it. Over time, bone tissue gradually grows in, tightly connecting the fixation wing 220 to the bone tissue. The tibial pad 30 is made of highly cross-linked material infused with vitamin E, exhibiting good wear resistance and biocompatibility. It connects to the tibial plateau 210 and forms a friction interface with the femoral component surface 180. During knee joint movement, the tibial pad 30, situated between the femoral component and the tibial plateau, bears friction and pressure. The incorporation of vitamin E improves the material's antioxidant properties, delaying material aging; the highly cross-linked structure enhances the material's strength and wear resistance.

[0044] By employing an alumina-based ceramic coating, wear resistance is improved, wear rate is reduced, friction debris is decreased, the risk of inflammatory response is lowered, the hardness of the femoral side friction interface is enhanced, and wear performance is improved. At the same time, good biocompatibility reduces the body's rejection response to the prosthesis, ensures smooth knee joint movement, and improves the prosthesis's lifespan.

[0045] See appendix Figure 1 -Appendix Figure 5 A method for preparing a knee joint prosthesis, specifically a tibial pad 30, includes the following steps:

[0046] S1. Raw material selection: Titanium alloy powder is used, which requires good flowability and uniform particle size distribution;

[0047] S2, 3D printing molding: Using CAD to build a precise three-dimensional model, and using electron beam 3D printing technology, titanium alloy powder is melted and solidified layer by layer according to the set parameters.

[0048] S3. Hot isostatic pressing: The printed parts are placed in a hot isostatic pressing equipment and processed at 920℃ and 100Mpa to improve density and performance.

[0049] S4. Annealing treatment: Annealing at 800℃ eliminates residual stress, optimizes crystal structure, and enhances overall performance.

[0050] The material preparation in S1 includes the following steps: titanium alloy powder is selected as the raw material for making the femoral condyle body. The powder should have good flowability and uniform particle size distribution to ensure that it can be spread evenly during the 3D printing process, ensuring printing accuracy and quality, and laying the foundation for the subsequent formation of a stable structure.

[0051] Specifically, titanium alloy powder with good flowability and uniform particle size distribution is selected. During 3D printing, the good flowability allows the powder to slide and spread smoothly on the printing platform, uniformly covering the designated area. The uniform particle size distribution ensures that each powder particle behaves consistently during the heating, melting, and solidification processes. When energy sources such as electron beams or lasers act on the powder layer, the uniformly sized powder can absorb energy simultaneously and in equal amounts, achieving uniform melting. During solidification, due to the uniform particle size, the resulting microstructure is also more uniform. This uniformity is crucial for subsequent hot isostatic pressing (HIP) and annealing processes. Under the high temperature and pressure of HIP, the uniform initial structure results in a uniform internal stress distribution, which can more effectively compact pores and repair defects. During annealing, the uniform structure can also more uniformly eliminate residual stress and optimize the crystal structure, thus laying a solid foundation for the formation of a stable femoral condyle body structure.

[0052] The high precision of 3D printing ensures that the dimensional and shape accuracy of the femoral condyle meets design requirements, reducing errors and defects during the printing process. The printed femoral condyle is of superior quality, with a dense and uniform internal structure and excellent mechanical properties, such as strength, toughness, and fatigue strength. After being integrated with components such as the trabecular meshwork 110, the stability of the entire femoral prosthesis is greatly improved, enabling it to better withstand various stresses generated during human movement.

[0053] The 3D printing process in S2 includes the following steps:

[0054] S201. Using computer-aided design (CAD) technology, based on the physiological structure and mechanical performance requirements of the human femoral condyle and the overall design standards of the knee joint prosthesis, accurately construct a three-dimensional model of the femoral condyle body.

[0055] S202. Using electron beam 3D printing technology, the selected titanium alloy powder is evenly spread on the printing platform. The electron beam is focused on the powder layer, and the powder is melted and solidified layer by layer according to the preset scanning path and energy parameters.

[0056] Specifically, computer-aided design (CAD) technology is used to integrate physiological structural data of the human femoral condyle. This data comes from precise scans and analyses of medical imaging (such as CT and MRI), covering anatomical features such as the shape, size, and curvature of the femoral condyle. Simultaneously, the mechanical performance requirements of the knee joint prosthesis are considered, taking into account various mechanical factors such as pressure, tension, and shear force experienced by the femoral condyle during human movement, as well as the overall design standards regarding compatibility with surrounding tissues and ease of installation. The powerful modeling capabilities of CAD software are used to transform this information into precise three-dimensional model data. During the modeling process, designers can repeatedly adjust and optimize the model, simulating mechanical performance under different design parameters to ensure the model meets all requirements. When using electron beam 3D printing technology, selected titanium alloy powder with good flowability and uniform particle size distribution is first evenly spread on the printing platform to form a uniformly thick powder layer. Under computer control, the electron beam moves according to the preset scanning path of the three-dimensional model constructed by S201, and the energy parameters are adjusted according to the structural requirements of different parts. When an electron beam is focused on a powder layer, the energy it carries causes the powder to melt rapidly. After the electron beam leaves, the molten powder quickly solidifies and bonds firmly with the solidified powder layer below. This process is repeated layer by layer, with each layer of powder precisely built upon the previous one, ultimately forming a complete femoral condyle body. During the printing process, precise control of parameters such as electron beam energy, scanning speed, and scanning spacing allows for precise control of the printed layer thickness, material density, and internal microstructure.

[0057] By converting a digital 3D model into a physical femoral condyle, complex structures can be precisely molded in a single step. The printed femoral condyle exhibits high dimensional accuracy and surface quality, with a dense and uniform internal structure free of significant pores and defects, resulting in excellent mechanical properties. Furthermore, due to the flexibility of electron beam 3D printing technology, complex shapes that are difficult to achieve using traditional processing methods can be manufactured, such as those with irregular internal support structures or porous structures that match human bone tissue, further enhancing the integration and stability of the prosthesis with the human body.

[0058] The hot isostatic pressing (HIP) process in S3 includes the following steps: The printed femoral condyle body is placed in a hot isostatic pressing (HIP) device and treated for a period of time at a high temperature of 920℃ and a high pressure of 100Mpa. The tiny pores and defects in the femoral condyle body are compacted and repaired, the density of the material is greatly improved, and the internal tissue is more uniform.

[0059] Specifically, during hot isostatic pressing (HIP), the printed femoral condyle body is placed inside an HIP apparatus, which creates a high-temperature environment of 920°C and a high-pressure environment of 100 MPa. Under high temperature, the activity of titanium alloy atoms increases, and the thermal motion of atoms intensifies. At this time, the atoms have sufficient energy to overcome the binding forces between them and can diffuse within the material. The high pressure provides the driving force for atomic diffusion, prompting atoms to migrate towards pores and defects. Under this synergistic effect of high temperature and high pressure, atoms around the tiny pores originally present in the femoral condyle body will gradually move towards the center of the pores under pressure, causing the pores to shrink until they are filled. For internal defects, such as microcracks, atoms will diffuse along the crack surface and fill the crack gaps, thus repairing the defects. At the same time, due to the uniform diffusion of atoms within the material, the originally uneven distribution of tissue composition is improved, making the internal structure more uniform and consistent, and the density of the material is thus greatly increased.

[0060] After hot isostatic pressing (HIP), the density of the femoral condyle body is significantly improved, and internal micropores and defects are essentially eliminated. This greatly optimizes the material's mechanical properties, significantly enhancing its strength, toughness, and fatigue strength. For example, under the same external force, the treated femoral condyle body is less prone to deformation and fracture, better adapting to the complex mechanical environment during human movement. Furthermore, the uniform internal structure ensures more consistent performance across different parts of the femoral condyle body, preventing premature failure due to localized performance differences and improving product quality stability and reliability.

[0061] The annealing process in S4 includes the following steps: After completing the hot isostatic pressing process, the femoral condyle body is annealed by heating it to 800°C and holding it for a certain time, followed by slow cooling to eliminate residual stress generated during 3D printing and hot isostatic pressing, optimize the crystal structure of the material, and further improve its overall performance.

[0062] Specifically, after hot isostatic pressing (HIP), residual stresses generated during 3D printing and HIP remain within the femoral condyle. These residual stresses are caused by uneven plastic deformation and thermal expansion / contraction experienced by different parts of the material during processing. When the femoral condyle is annealed, it is heated to 800°C and held for a certain time. At this temperature, the atoms gain sufficient energy to become active, enabling them to move and rearrange to some extent. As the temperature increases, the thermal vibrations of the atoms intensify, and the bond energy between atoms relatively weakens, allowing the residual stresses previously locked in the crystal lattice to be released. The atoms spontaneously adjust from high-energy states to low-energy states to achieve a more stable state. Holding this position for a period ensures sufficient stress release, resulting in a more uniform stress distribution within the material. The subsequent slow cooling process is also crucial. Slow cooling allows sufficient time for the atoms to arrange themselves in an orderly manner, promoting the optimization of the crystal structure. During cooling, the atoms recombine according to more stable crystal structure rules, reducing lattice defects and making the crystal structure more complete and ordered, thereby further improving the overall performance of the material.

[0063] Annealing effectively eliminates residual stress generated during the initial processing of the femoral condyle, preventing product deformation and cracking caused by stress concentration. The optimized crystal structure reduces internal defects and promotes a more regular atomic arrangement, significantly improving the material's overall performance.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A knee prosthesis comprising a trabecular intraosseous type (110), characterized in that, The trabecular intra-type (110) is provided with a front condyle side (150) on one side, and is provided with a notch on the other side, and the two ends of the notch are provided with a distal end side (160), the upper surface of the distal end side (160) is provided with a trabecular column (120), one side of the distal end side (160) is provided with a posterior condyle side (170), the side wall of the trabecular intra-type (110) is provided with a femoral condyle body (130), the inside of the trabecular column (120) is provided with a column (140), one side of the posterior condyle side (170) is provided with a femoral component surface (180), the outer wall of the femoral component surface (180) is provided with a tibial pad (30), the upper surface of the tibial pad (30) is provided with a tibial platform (210), one side of the tibial platform (210) is provided with a trabecular platform layer (240), the middle part of the tibial platform (210) is provided with a fixed wing (220), one side of the trabecular platform layer (240) is provided with a plurality of fixed nails (230), and the middle part of the trabecular platform layer (240) is provided with a Y-shaped groove, and the Y-shaped groove is symmetrically provided with a trabecular reinforcing block (250) inside. The tibial platform (210) and the fixed nail (230) are made of 3D printed titanium alloy powder, the tibial platform (210) is used as the matrix of the tibial side, the tibial platform (210) and the trabecular platform layer (240) are combined, the tibial platform (210) and the trabecular platform layer (240) are fixed, the fixed nail (230) is in the shape of a cross, the trabecular platform layer (240) is used for short-term fixation, the trabecular platform layer (240) and the tibial platform (210) are used for the fixed support of the tibial platform, the fixed wing (220) has longitudinal texture, the fixed wing (220) is used for short-term fixation, the trabecular reinforcing block (250) is used for fixing the bone ingrowth of the fixed wing (220), and the tibial pad (30) is made of mixed vitamin E high crosslinking, the tibial pad (30) is connected with the tibial platform (210), and the tibial pad (30) is used for the friction interface of the femoral component surface (180).

2. A knee prosthesis according to claim 1, wherein, The trabecular intra-type (110) and the trabecular column (120) are made of 3D printed titanium alloy powder, the trabecular intra-type (110) and the trabecular column (120) are treated by 920℃ hot isostatic pressing 100Mpa and 800℃ annealing, and the trabecular intra-type (110) and the trabecular column (120) are used for fixation of the prosthesis.

3. The knee prosthesis of claim 1, wherein, The femoral condyle body (130) and the column (140) are made of 3D printed titanium alloy powder, the femoral condyle body (130) is used for the base of the femoral side, the femoral condyle body (130) and the trabecular bone type (110) are combined, the femoral condyle body (130) and the trabecular bone type (110) are fixed, the column (140) and the trabecular bone column (120) are connected, and the column (140) and the trabecular bone column (120) are fixed.

4. The knee prosthesis of claim 1, wherein, The material of the femoral component surface (180) is made of 3D printed titanium alloy powder, the surface of the femoral component surface (180) is coated with an alumina-based coating, the coating thickness can reach 100-250μm, and the femoral component surface (180) improves the friction interface hardness and wear resistance.

5. A knee prosthesis according to any one of claims 1-4, characterized in that The preparation method of the tibial pad (30) comprises the following steps: S1, raw material selection, titanium alloy powder is used, and good fluidity and uniform particle size distribution are required; S2, 3D printing forming, a precise three-dimensional model is built by CAD, and the titanium alloy powder is melted and solidified layer by layer according to the set parameters by electron beam 3D printing technology; S3, hot isostatic pressing treatment, the printed part is placed in a hot isostatic pressing device and treated at 920℃ and 100Mpa; S4, annealing treatment, annealing at 800℃ to eliminate residual stress, optimize crystal structure and enhance comprehensive performance.

6. A knee prosthesis according to claim 5, wherein, The material preparation in S1 includes the following steps: titanium alloy powder is selected as the raw material for making the femoral condyle body, and the powder should have good fluidity and uniform particle size distribution to ensure uniform spreading during 3D printing.

7. A knee prosthesis according to claim 5, wherein, The 3D printing forming in S2 includes the following steps: S201, using computer aided design (CAD) technology, a three-dimensional model of the femoral condyle body is accurately built according to the physiological structure, mechanical properties and overall design standard of the knee joint prosthesis; S202, using electron beam 3D printing technology, the selected titanium alloy powder is uniformly spread on the printing platform, the electron beam is focused on the powder layer, and the powder is melted and solidified layer by layer according to the preset scanning path and energy parameters.

8. The knee prosthesis of claim 5, wherein, The hot isostatic pressing treatment in S3 includes the following steps: the printed femoral condyle body is placed in a hot isostatic pressing device, and treated at 920℃ and 100Mpa for a period of time, and the micro-pores and defects in the femoral condyle body are compacted and repaired.

9. The knee prosthesis of claim 5, wherein, The annealing treatment in S4 includes the following steps: After hot isostatic pressing treatment, the femoral condyle body is annealed by heating it to 800℃ and keeping it for a certain period of time, and then slowly cooling to eliminate the residual stress generated during 3D printing and hot isostatic pressing.

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