Knee joint prosthesis

Abstract

The invention relates to the technical field of medical instruments, and discloses a knee joint prosthesis which comprises a bone trabecula inner model, one side of the bone trabecula inner model is provided with an anterior condyle side, the other side of the bone trabecula inner model is provided with a notch, the two ends of the notch of the bone trabecula inner model are provided with far-end sides, the upper surfaces of the far-end sides are provided with bone trabecula stand columns, and the upper surfaces of the far-end sides are provided with bone trabecula vertical columns. A posterior condyle side is arranged on one side of the far end side, a femoral condyle body is arranged on the side wall of the bone trabecula inner model, a stand column is arranged in the bone trabecula stand column, a femoral component surface is arranged on one side of the posterior condyle side, and a femoral component surface is arranged on the outer wall of the femoral component surface. By means of the thighbone side prosthesis, better fusion of the thighbone side prosthesis and bone tissue is achieved, bone ingrowth is promoted, and the long-term stable fixing effect is achieved. The problems that a traditional thighbone side prosthesis is poor in long-term stability and prone to loosening, and a friction interface is prone to abrasion are solved, the service life of the prosthesis is prolonged, and the life quality of a patient is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and specifically relates to a knee joint prosthesis. Background Art

[0002] In knee joint replacement surgery, achieving bone ingrowth at the bone contact interface of the prosthesis to achieve long-term stability is a key goal to ensure the surgical effect and the quality of life of patients. At present, there are many challenges in the knee joint prostheses used clinically in this regard.

[0003] Traditional bone cement knee joint prostheses are widely used. In the initial stage of implantation, with the mechanical anchoring effect of bone cement and bone tissue, they can provide good short-term stability, enabling patients to perform moderate activities in the short term after surgery. However, as time goes by, problems gradually emerge. Bone cement, as a foreign body, will trigger a series of biological reactions in the body, resulting in a decrease in the bonding strength at the interface with bone tissue. At the same time, the stress generated by human activities will continuously act on the prosthesis, bone cement, and bone tissue interface, causing phenomena such as fatigue wear and microcrack propagation of bone cement, making the prosthesis prone to loosening and sinking during long-term use, unable to maintain stable bone contact, and seriously affecting the service life of the prosthesis and the long-term curative effect of patients. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a knee joint prosthesis, which solves the problem of poor long-term stability of traditional femoral side prostheses.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A knee joint prosthesis includes an intratrabecular type. On one side of the intratrabecular type is provided an anterior condyle side, on the other side is provided a notch, at both ends of the notch of the intratrabecular type are provided distal sides, on the upper surface of the distal sides are provided trabecular columns, on one side of the distal sides is provided a posterior condyle side, on the side wall of the intratrabecular type is provided a femoral condyle body, inside the trabecular columns is provided a column, on one side of the posterior condyle side is provided a femoral component surface, on the outer wall of the femoral component surface is provided, on the upper surface of which is provided a tibial plateau, on one side of the tibial plateau is provided a trabecular platform layer, in the middle of the tibial plateau is provided a fixing wing, on one side of the trabecular platform layer are provided a number of fixing nails, in the middle of the trabecular platform layer is provided a Y-shaped groove, and symmetrically arranged in the Y-shaped groove of the trabecular platform layer are trabecular strengthening blocks.

[0006] Preferably, the intratrabecular type and the trabecular columns are made of 3D printed titanium alloy powder, and the intratrabecular type and the trabecular columns are subjected to hot isostatic pressing at 920°C under 100 Mpa and annealing treatment at 800°C, and the intratrabecular type and the trabecular columns are used for the fixation of the prosthesis.

[0007] Preferably, the femoral condyle body and the column are made of 3D printing titanium alloy powder. The femoral condyle body is used as the matrix on the femoral side. The femoral condyle body is combined with and fixed to the internal trabecular pattern. The column is connected to and fixed to the trabecular column.

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

[0009] Preferably, the tibial plateau and the fixing nail are made of 3D printing titanium alloy powder. The tibial plateau is used as the matrix on the tibial side. The tibial plateau is combined with and fixed to the trabecular platform layer. The fixing nail has a cross-shaped appearance. The trabecular platform layer is used for short-term fixation. The trabecular platform layer and the tibial plateau are used for the fixation and support of the tibial plateau. The fixing wing has longitudinal textures on its outer shape and is used for short-term fixation. The trabecular strengthening block is used for the bone ingrowth to fix the fixing wing. It is made of highly cross-linked by blending vitamin E and is connected to the tibial plateau and is used for the friction interface on the surface of the femoral component.

[0010] Preferably, a preparation method for a tibial pad of a knee joint prosthesis includes the following steps: S1. Raw material selection: Titanium alloy powder is used, and it is required to have good fluidity and uniform particle size distribution. S2. 3D printing and forming: With the help of CAD, an accurate three-dimensional model is constructed, and the electron beam 3D printing technology is used to make the titanium alloy powder melt and solidify layer by layer according to the set parameters. S3. Hot isostatic pressing treatment: The printed component is placed in a hot isostatic pressing device and treated under the conditions of 920 °C and 100 Mpa to improve the density and performance. S4. Annealing treatment: Annealing is carried out at 800 °C to eliminate residual stress, optimize the crystal structure, and enhance the comprehensive performance.

[0011] Preferably, the material preparation in S1 includes the following steps: Select titanium alloy powder as the raw material for making the femoral condyle body. This powder should have good fluidity and uniform particle size distribution to ensure uniform spreading during 3D printing, guarantee the printing accuracy and quality, and lay a foundation for forming a stable structure in the subsequent process.

[0012] Preferably, the 3D printing and forming in S2 includes the following steps: S201. Using computer-aided design (CAD) technology, accurately construct a three-dimensional model of the femoral condyle body according to the physiological structure, mechanical property requirements of the human femoral condyle, and the overall design standards of the knee joint prosthesis. S202. Using electron beam 3D printing technology, evenly spread the selected titanium alloy powder on the printing platform. Focus the electron beam on the powder layer and, according to the preset scanning path and energy parameters, melt and solidify the powder layer by layer to form a shape.

[0013] Preferably, the hot isostatic pressing treatment in S3 includes the following steps: Put the printed femoral condyle body into a hot isostatic pressing device and treat it for a period of time under the high temperature of 920 °C and the high pressure of 100 Mpa. The tiny pores and defects in the femoral condyle body will be compacted and repaired, the density of the material will be greatly increased, and the internal structure will be more uniform.

[0014] Preferably, the annealing treatment in S4 includes the following steps: After the hot isostatic pressing treatment, perform annealing treatment on the femoral condyle body. Heat it to 800 °C and maintain it for a certain time, and then slowly cool it to eliminate the residual stress generated during 3D printing and hot isostatic pressing, optimize the crystal structure of the material, and further improve its comprehensive performance.

[0015] Working principle: Select titanium alloy powder with good fluidity and uniform particle size distribution. Good fluidity ensures that the powder can be evenly spread during 3D printing, and uniform particle size distribution ensures consistent melting and solidification behavior of the powder when heated, laying a foundation for the subsequent formation of a stable structure. For example, the titanium alloy powder used to make the femoral condyle body makes the printed body have high precision and good quality.

[0016] In terms of structural design, both the femoral side and the tibial side have unique structures. The intratrabecular type and trabecular struts on the femoral side have an irregular network structure and cooperate with components such as the femoral condyle body. The intratrabecular type is fixed in the sagittal plane and cross-section, and the trabecular struts are strengthened and fixed in the coronal plane and sagittal plane to promote bone ingrowth and enhance long-term stability. The tibial plateau on the tibial side is combined with the trabecular platform layer, the fixing wings and cross-shaped fixing nails achieve short-term fixation, and the trabecular reinforcement blocks promote bone ingrowth at the fixing wing.

[0017] In terms of the processing technology, first, the computer-aided design (CAD) technology is used to construct a three-dimensional model based on the human physiological structure, mechanical property requirements, and overall design standards. Then, the electron beam 3D printing technology is applied to layer by layer melt and solidify the titanium alloy powder to form a shape. After that, the printed parts are subjected to hot isostatic pressing treatment. Under the conditions of 920 °C and 100 Mpa, the pores are compacted, the defects are repaired, and the material density and uniformity are improved. Finally, through annealing treatment, it is heated to 800 °C and slowly cooled after maintaining for a certain time to eliminate the residual stress, optimize the crystal structure, and enhance the comprehensive performance. In addition, an alumina-based coating with a thickness of 100 - 250 μm is coated on the surface of the femoral component to enhance the hardness and wear resistance of the friction interface; the tibial pad is made of high cross-linking with vitamin E doped to reduce the wear rate.

[0018] The present invention provides a knee joint prosthesis. It has the following beneficial effects: 1. The present invention realizes better fusion between the femoral component of the knee joint prosthesis and bone tissue through the femoral component of the knee joint prosthesis, promotes bone ingrowth, and achieves the effect of long-term stable fixation. It solves the problems of poor long-term stability, easy loosening of the traditional femoral component, and easy wear of the friction interface, and improves the service life of the prosthesis and the quality of life of patients.

[0019] 2. Through the constructed structure of the femoral component of the knee joint prosthesis in the present invention, the femoral component of the knee joint prosthesis can better adapt to various mechanical loads generated during human movement, evenly disperse stress, and avoid damage or loosening of the prosthesis caused by stress concentration. At the same time, the use of titanium alloy material realizes the lightweight design of the prosthesis, reduces the burden on the patient's limb, and improves the body adaptability after implantation.

[0020] 3. Through the treatment with an alumina-based ceramic coating in the present invention, the wear strength is improved, the wear rate is reduced, the debris generated by friction is reduced, the risk of inflammatory reaction is reduced, the hardness of the femoral-side friction interface is enhanced, and the wear performance is improved. At the same time, the good biocompatibility reduces the rejection reaction of the human body to the prosthesis, ensures the smooth movement of the knee joint, and improves the service life of the prosthesis.

[0021] 4. Due to the high precision of 3D printing, both the dimensional accuracy and shape accuracy of the femoral condyle body can meet the design requirements, reducing errors and defects during the printing process. The printed femoral condyle body has excellent quality, a dense and uniform internal structure, and good mechanical properties. After being combined with components such as the cancellous bone inner type in the follow-up, the stability of the entire femoral component of the knee joint prosthesis is greatly improved, and it can better withstand various stresses generated during human movement. Description of the Drawings

[0022] Figure 1 It is a three-dimensional structural schematic diagram of a knee joint prosthesis proposed by the present invention; Figure 2 It is a partial structural schematic diagram of the femoral condyle body of a knee joint prosthesis proposed by the present invention; Figure 3 Schematic diagram of a partial structure of the tibial plateau of a knee joint prosthesis proposed by the present invention; Figure 4 Schematic diagram of a partial structure of the trabecular bone platform layer of a knee joint prosthesis proposed by the present invention; Figure 5 Schematic diagram of a partial structure of the tibial pad of a knee joint prosthesis proposed by the present invention.

[0023] Among them, 110, inner type of trabecular bone; 120, trabecular bone column; 130, femoral condyle body; 140, column; 150, anterior condyle side; 160, distal side; 170, posterior condyle side; 180, surface of femoral component; 210, tibial plateau; 220, fixing wing; 230, fixing nail; 240, trabecular bone platform layer; 250, trabecular bone strengthening block; 30, tibial pad. Specific embodiments

[0024] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to the attached Figure 1 - attached Figure 5 , a knee joint prosthesis, including an inner type of trabecular bone 110, an anterior condyle side 150 is arranged on one side of the inner type of trabecular bone 110, a notch is arranged on the other side of the inner type of trabecular bone 110, distal sides 160 are arranged at both ends of the notch of the inner type of trabecular bone 110, trabecular bone columns 120 are arranged on the upper surfaces of the distal sides 160, a posterior condyle side 170 is arranged on one side of the distal sides 160, a femoral condyle body 130 is arranged on the side wall of the inner type of trabecular bone 110, a column 140 is arranged inside the trabecular bone columns 120, a femoral component surface 180 is arranged on one side of the posterior condyle side 170, a tibial pad 30 is arranged on the outer wall of the femoral component surface 180, a tibial plateau 210 is arranged on the upper surface of the tibial pad 30, a trabecular bone platform layer 240 is arranged on one side of the tibial plateau 210, fixing wings 220 are arranged in the middle of the tibial plateau 210, a plurality of fixing nails 230 are arranged on one side of the trabecular bone platform layer 240, a Y-shaped groove is arranged in the middle of the trabecular bone platform layer 240, and trabecular bone strengthening blocks 250 are symmetrically arranged in the Y-shaped groove of the trabecular bone platform layer 240.

[0026] Specifically, the trabecular inner type 110 and the trabecular column 120 are both made of 3D printed titanium alloy powder and are subjected to hot isostatic pressing at 920 °C under 100 Mpa and annealing treatment at 800 °C. This treatment endows them with high strength and an appropriate microstructure. The trabecular inner type 110 has an irregular network structure, which is connected to the anterior condylar side 150, the distal side 160, and the posterior condylar side 170, forming a stable support in the sagittal plane and the cross-section; the trabecular column 120 further strengthens the fixation in the coronal plane and the sagittal plane. The femoral condyle body 130, as the femoral side matrix, is tightly combined with the trabecular inner type 110, and the column 140 is connected to the trabecular column 120, jointly constituting a stable mechanical structure. The surface 180 of the femoral component is coated with an alumina-based coating of 100 - 250 μm. This design enhances the hardness of the friction interface and improves the wear performance; the tibial plateau 210 is made of 3D printed titanium alloy powder. As the tibial side matrix, it is tightly combined with the trabecular platform layer 240, providing stable support for the tibia. The fixing wing 220 has longitudinal textures, and the fixing nail 230 is in a cross shape. In the initial stage of prosthesis implantation, the two work together to achieve short-term fixation and prevent prosthesis displacement. The trabecular platform layer 240 not only assists in fixation, but its special structure also creates conditions for bone ingrowth and enhances long-term stability. The trabecular strengthening block 250 located in the Y-shaped groove in the middle of the trabecular platform layer 240 further promotes bone ingrowth at the fixing wing 220 and optimizes the fixation effect. The tibial pad 30 is made of high cross-linked material blended with vitamin E, is connected to the tibial plateau 210, and forms a friction interface with the surface 180 of the femoral component, effectively reducing the wear rate and improving the wear resistance.

[0027] Through the femoral side prosthesis, better integration between the femoral side prosthesis and bone tissue is achieved, promoting bone ingrowth and achieving the effect of long-term stable fixation. It solves the problems of poor long-term stability, easy loosening of traditional femoral side prostheses, and easy wear of the friction interface, improving the service life of the prosthesis and the quality of life of patients.

[0028] Refer to the appendix Figure 1 - appendix Figure 5, the trabecular inner type 110 and the trabecular column 120 are made of 3D printed titanium alloy powder. The trabecular inner type 110 and the trabecular column 120 are subjected to hot isostatic pressing at 920 °C and 100 Mpa and annealing treatment at 800 °C, and the trabecular inner type 110 and the trabecular column 120 are used for the fixation of the prosthesis; the femoral condyle body 130 and the column 140 are made of 3D printed titanium alloy powder. The femoral condyle body 130 is used as the matrix on the femoral side. The femoral condyle body 130 is combined with the trabecular inner type 110 and fixed to the trabecular inner type 110. The column 140 is connected to the trabecular column 120 and fixed to the trabecular column 120; the material of the femoral component surface 180 is made of 3D printed titanium alloy powder. An alumina-based coating is applied to the surface of the femoral component surface 180, and the coating thickness can reach 100 - 250 μm, which improves the hardness and wear resistance of the friction interface of the femoral component surface 180.

[0029] Specifically, the trabecular inner type 110 and the trabecular struts 120 are made of 3D printed titanium alloy powder. This manufacturing method can precisely shape an irregular network structure, enabling it to have microscopic structural characteristics similar to human bone tissue. Subsequently, hot isostatic pressing at 920°C under 100 Mpa and annealing treatment at 800°C are carried out. During the hot isostatic pressing process, the high-temperature and high-pressure environment compacts the tiny pores inside the titanium alloy, making the tissue more dense and uniform; the annealing treatment eliminates the residual stress generated during printing and hot isostatic pressing and optimizes the crystal structure. In the prosthesis, the trabecular inner type 110, with its irregular network 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 struts 120 further strengthen this anchorage in the coronal and sagittal planes. The two cooperate with each other to enhance the connection between the prosthesis and the bone tissue from multiple dimensions; the femoral condyle body 130 and the struts 140 are both made of 3D printed titanium alloy powder, ensuring material consistency and structural accuracy. The femoral condyle body 130, as the matrix on the femoral side, provides the main support structure for the entire femoral side prosthesis. It is combined and fixed with the trabecular inner type 110 through a specific structural design. The irregular network structure of the trabecular inner type 110 is embedded in the corresponding part of the femoral condyle body 130 to achieve mechanical locking and integrated connection. The struts 140 are connected and fixed to the trabecular struts 120. On the basis that the trabecular struts 120 provide multi-planar fixation for the prosthesis, the struts 140 further enhance the overall structural stability, disperse and transmit the stress from human movement, enabling the prosthesis to remain stable under complex loading conditions; the surface 180 of the femoral component 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. The alumina-based coating has characteristics such as high hardness, good wear resistance, and biocompatibility. During the use of the prosthesis, this coating serves as a friction interface and interacts with the relatively moving components (such as the tibial insert 30). The high-hardness coating can effectively resist wear during the friction process and reduce material loss; at the same time, the microstructure and composition of the coating help to reduce the friction coefficient, making joint movement smoother.

[0030] Through the constructed femoral side prosthesis structure, the femoral side prosthesis can better adapt to various mechanical loads generated during human movement, evenly disperse stress, and avoid prosthesis damage or loosening caused by stress concentration. At the same time, the use of titanium alloy material realizes the lightweight design of the prosthesis, reduces the burden on the patient's limb, and improves the post-implant body adaptability.

[0031] Refer to the appendix Figure 3 Appendix Figure 5, the tibial plateau 210 and the fixation pins 230 are made of 3D printed titanium alloy powder. The tibial plateau 210 serves as the matrix on the tibial side. The tibial plateau 210 is combined and fixed with the trabecular platform layer 240. The fixation pins 230 are cross-shaped. The trabecular platform layer 240 is used for short-term fixation. The trabecular platform layer 240 and the tibial plateau 210 are used for the fixation and support of the tibial plateau. The fixation wings 220 have longitudinal textures on their outer shapes. The fixation wings 220 are used for short-term fixation. The trabecular reinforcement blocks 250 are used for the bone ingrowth to fix the fixation wings 220. The tibial pad 30 is made of highly crosslinked material blended with vitamin E. The tibial pad 30 is connected to the tibial plateau 210. The tibial pad 30 is used for the friction interface on the surface 180 of the femoral component.

[0032] Specifically, the tibial plateau 210 and the fixation pins 230 are made of 3D printed titanium alloy powder, which enables them to have precise shapes and microstructures. The tibial plateau 210 serves as the matrix on the tibial side and is tightly combined and fixed with the trabecular platform layer 240. The trabecular platform layer 240 has a special structure. In the initial stage of prosthesis implantation, it can be initially combined with the surrounding tissues by virtue of its own structure to achieve short-term fixation. At the same time, it and the tibial plateau 210 jointly provide stable fixation and support for the tibia. The fixation pins 230 are cross-shaped, and this shape design increases the contact area and anchoring force with bone tissue. During implantation, the fixation pins 230 are implanted into the bone tissue and pull the tibial plateau 210 and the trabecular platform layer 240 from multiple directions to prevent their displacement. The fixation wings 220 have longitudinal textures on their outer shapes. During surgical implantation, these textures increase the friction with the surrounding bone tissue and can quickly fix the tibial plateau 210 locally, playing a role in short-term fixation. The trabecular reinforcement blocks 250 are located near the fixation wings 220, and they create favorable conditions for the bone ingrowth at the fixation wings 220. The trabecular reinforcement blocks 250 have a porous structure similar to human trabeculae, which can guide the growth of bone cells inside. Over time, bone tissue gradually grows in and tightly connects the fixation wings 220 with the bone tissue. The tibial pad 30 is made of highly crosslinked material blended with vitamin E. This material has good wear resistance and biocompatibility. It is connected to the tibial plateau 210 and forms a friction interface with the surface 180 of the femoral component. During knee joint movement, the tibial pad 30 is located between the femoral component and the tibial plateau, bearing friction and pressure. The incorporation of vitamin E improves the antioxidant performance of the material and delays material aging. The highly crosslinked structure enhances the strength and wear resistance of the material.

[0033] By adopting the treatment with alumina-based ceramic coating, the wear strength is improved, the wear rate is reduced, the debris generated by friction is decreased, the risk of inflammatory reaction is lowered, the hardness of the femoral-side friction interface is enhanced, and the wear performance is improved. At the same time, the good biocompatibility reduces the rejection reaction of the human body to the prosthesis, ensures the smooth movement of the knee joint, and increases the service life of the prosthesis.

[0034] Refer to the appendix Figure 1 - appendix Figure 5 , a method for preparing a tibial insert 30 of a knee joint prosthesis, comprising the following steps: S1. Raw material selection: Titanium alloy powder is used, and it is required to have good fluidity and uniform particle size distribution. S2. 3D printing and forming: With the aid of CAD, an accurate three-dimensional model is constructed, and the electron beam 3D printing technology is used to make the titanium alloy powder melt and solidify layer by layer according to the set parameters. S3. Hot isostatic pressing treatment: The printed component is placed in a hot isostatic pressing device and treated under the conditions of 920 °C and 100 Mpa to improve the density and performance. S4. Annealing treatment: Annealing is carried out at 800 °C to eliminate residual stress, optimize the crystal structure, and enhance the comprehensive performance.

[0035] The material preparation in S1 includes the following steps: Select titanium alloy powder as the raw material for making the femoral condyle body. This powder should have good fluidity and uniform particle size distribution to ensure uniform spreading during 3D printing, guarantee the printing accuracy and quality, and lay a foundation for the subsequent formation of a stable structure.

[0036] Specifically, select titanium alloy powder with good fluidity and uniform particle size distribution. During 3D printing, the good fluidity enables the powder to slide and spread smoothly on the printing platform and evenly cover the specified area. The uniform particle size distribution ensures that each powder particle behaves consistently during the process of heating, melting, and solidifying. When an energy source such as an electron beam or laser acts on the powder layer, the powder with uniform particle size can absorb energy simultaneously and equally, achieving uniform melting. During the solidification process, due to the uniform particle size, the formed microstructure is also more uniform. This uniformity is crucial for subsequent hot isostatic pressing and annealing treatments. Because in the high temperature and high pressure of hot isostatic pressing, with a uniform initial structure, the internal stress distribution is uniform, which can more effectively compact pores and repair defects; during annealing treatment, the uniform structure can also more evenly eliminate residual stress and optimize the crystal structure, thus laying a solid foundation for the formation of a stable femoral condyle body structure.

[0037] Due to the high precision of 3D printing, both the dimensional accuracy and shape accuracy of the femoral condyle body can meet the design requirements, reducing errors and defects during the printing process. The printed femoral condyle body is of high quality, with a dense and uniform internal structure and good mechanical properties such as strength, toughness, and fatigue strength. After subsequent combination with components such as the trabecular bone inner type 110, the stability of the entire femoral side prosthesis is greatly improved, enabling it to better withstand various stresses generated during human movement.

[0038] The 3D printing and forming in S2 includes the following steps: S201. Using computer-aided design (CAD) technology, based on the physiological structure, mechanical property requirements of the human femoral condyle, and the overall design standards of the knee joint prosthesis, precisely construct a three-dimensional model of the femoral condyle body; S202. Employing electron beam 3D printing technology, evenly sprinkle the selected titanium alloy powder on the printing platform. Focus the electron beam on the powder layer and, according to the preset scanning path and energy parameters, melt and solidify the powder layer by layer to form a shape.

[0039] Specifically, using computer-aided design (CAD) technology, integrate the physiological structure data of the human femoral condyle. These data are derived from the precise scanning and analysis of medical images (such as CT, MRI, etc.), covering anatomical features such as the shape, size, and curvature of the femoral condyle. At the same time, combined with the mechanical property requirements of the knee joint prosthesis, consider various mechanical factors such as the pressure, tension, and shear force borne by the femoral condyle during human movement, as well as the regulations on the compatibility with surrounding tissues and installation convenience in the overall design standards. Through the powerful modeling function of CAD software, convert the above information into precise three-dimensional model data. During the modeling process, designers can repeatedly adjust and optimize the model, simulate the mechanical property performance under different design parameters, and ensure that the model meets various requirements; when using electron beam 3D printing technology, first evenly sprinkle the selected titanium alloy powder with good fluidity and uniform particle size distribution on the printing platform to form a powder layer with a uniform thickness. Under the control of the computer, the electron beam moves along the scanning path preset by the three-dimensional model constructed in S201 and adjusts the energy parameters according to the structural requirements of different parts. When the electron beam focuses on the powder layer, the energy it carries rapidly melts the powder. After the electron beam leaves, the melted powder quickly solidifies and firmly combines with the solidified powder layer below. Repeat this layer by layer, and each layer of powder is precisely stacked on the previous layer, finally forming a complete femoral condyle body. During the printing process, by precisely controlling parameters such as the energy, scanning speed, and scanning spacing of the electron beam, precise control of the printing layer thickness, material density, and internal microstructure can be achieved.

[0040] The digital three-dimensional model is transformed into a physical femoral condyle body, achieving one-time precise forming of complex structures. The printed femoral condyle body has high dimensional accuracy and surface quality, with a dense and uniform internal structure, no obvious pores and defects, and excellent mechanical properties. At the same time, due to the flexibility of electron beam 3D printing technology, complex shapes that are difficult to achieve by traditional processing methods can be manufactured, such as those with irregular internal support structures or porous structures that match human bone tissue, further improving the fusion and stability between the prosthesis and the human body.

[0041] The hot isostatic pressing treatment in S3 includes the following steps: putting the printed femoral condyle body into a hot isostatic pressing device, and treating it for a period of time under a high temperature of 920 °C and a high pressure of 100 Mpa. The tiny pores and defects in the femoral condyle body will be compacted and repaired, the density of the material will be greatly improved, and the internal tissue will be more uniform.

[0042] Specifically, during the hot isostatic pressing treatment, the printed femoral condyle body is placed in a hot isostatic pressing device, and the device creates a high temperature environment of 920 °C and a high pressure environment of 100 Mpa. Under the action of high temperature, the activity of titanium alloy atoms is enhanced, and the thermal movement of atoms is intensified. At this time, the atoms have enough energy to overcome the binding force between each other and can diffuse inside the material. And the high pressure provides the driving force for the diffusion of atoms, prompting the atoms to migrate towards the pores and defects. Under the synergistic action of this high temperature and high pressure, the atoms around the tiny pores originally existing in the femoral condyle body will gradually move towards the center of the pores under the push of pressure, causing the pores to continuously shrink until they are filled; for internal defects such as microcracks, the atoms will diffuse along the crack surface and fill the crack gap to achieve the repair of the defects. At the same time, due to the uniform diffusion of atoms inside the material, the originally uneven distribution of tissue components is improved, making the internal tissue more uniform, and the density of the material is also greatly increased accordingly.

[0043] After the hot isostatic pressing treatment, the density of the femoral condyle body is significantly increased, and the tiny pores and defects inside are basically eliminated. This greatly optimizes the mechanical properties of the material, and its strength, toughness, and fatigue strength are all significantly enhanced. For example, when bearing the same external force, the treated femoral condyle body is less likely to deform, break, etc., and can better adapt to the complex mechanical environment during human movement. Moreover, the uniform internal tissue makes the performance of the femoral condyle body more consistent in each part, avoiding premature failure caused by local performance differences and improving the stability and reliability of product quality.

[0044] The annealing treatment in S4 includes the following steps: After completing the hot isostatic pressing treatment, the femoral condyle body is annealed, heated to 800 °C, and maintained for a certain period of time, and then slowly cooled to eliminate the residual stress generated during 3D printing and hot isostatic pressing, optimize the crystal structure of the material, and further improve its comprehensive performance.

[0045] Specifically, after completing the hot isostatic pressing treatment, there is residual stress in the femoral condyle body generated during 3D printing and hot isostatic pressing. These residual stresses are caused by uneven plastic deformation, thermal expansion and contraction, etc. in different parts of the material during the processing. When annealing the femoral condyle body, it is heated to 800 °C and maintained for a certain period of time. At this temperature, atoms obtain sufficient energy to become active and can move and rearrange to a certain extent. As the temperature rises, the thermal vibration of atoms intensifies, and the bond energy between atoms weakens relatively, enabling the residual stress originally locked in the crystal lattice to be released. Atoms will spontaneously adjust from a high-energy state to a low-energy state to reach a more stable state. Maintaining for a period of time can ensure the full release of stress and make the stress distribution inside the material more uniform. The subsequent slow cooling process is also crucial. Slow cooling allows atoms to have enough time for orderly arrangement and promotes the optimization of the crystal structure. During the cooling process, atoms will recombine according to the rules of a more stable crystal structure, reducing lattice defects and making the crystal structure more complete and orderly, thereby further improving the comprehensive performance of the material.

[0046] Through the annealing treatment, the residual stress generated in the femoral condyle body during the previous processing is effectively eliminated, avoiding problems such as product deformation and cracking caused by residual stress concentration. The optimized crystal structure reduces the internal defects of the material and makes the atomic arrangement more regular, thus significantly improving the comprehensive performance of the material.

[0047] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A knee joint prosthesis, comprising a trabecular endotype (110), characterized in that: The trabecular inner mold (110) is provided with an anterior condyle side (150) on one side, and a notch is provided on the other side of the trabecular inner mold (110). The two ends of the notch of the trabecular inner mold (110) are provided with distal sides (160). The upper surface of the distal side (160) is provided with a trabecular column (120). One side of the distal side (160) is provided with a posterior condyle side (170). The side wall of the trabecular inner mold (110) is provided with a femoral condyle body (130). The interior of the trabecular column (120) is provided with a column (140). One side of the posterior condyle side (170) is provided with a femoral part. The femoral component surface (180) is provided with a tibial pad (30) on the outer wall of the femoral component surface (180), a tibial platform (210) is provided on the upper surface of the tibial pad (30), a trabecular platform layer (240) is provided on one side of the tibial platform (210), a fixing wing (220) is provided in the middle of the tibial platform (210), a plurality of fixing nails (230) are provided on one side of the trabecular platform layer (240), a Y-shaped groove is provided in the middle of the trabecular platform layer (240), and trabecular reinforcement blocks (250) are symmetrically arranged in the Y-shaped groove of the trabecular platform layer (240).

2. A knee joint prosthesis according to claim 1, characterized in that: The trabecular inner mold (110) and the trabecular column (120) are made of 3D printed titanium alloy powder, the trabecular inner mold (110) and the trabecular column (120) are subjected to 920°C hot isostatic pressing at 100 MPa and 800°C annealing treatment, and the trabecular inner mold (110) and the trabecular column (120) are used for fixation of a prosthesis.

3. A knee joint prosthesis according to claim 1, characterized in that: The femoral condyle body (130) and the column (140) are made of 3D printed titanium alloy powder. The femoral condyle body (130) is used as a base on the femoral side. The femoral condyle body (130) is combined with a trabecular bone inner mold (110). The femoral condyle body (130) and the trabecular bone inner mold (110) are fixed to each other. The column (140) and the trabecular bone column (120) are connected. The column (140) and the trabecular bone column (120) are fixed to each other.

4. A knee joint prosthesis according to claim 1, characterized in that: The material of 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 aluminum oxide-based coating, the coating thickness can reach 100-250 μm, and the femoral component surface (180) improves the hardness and wear resistance of the friction interface.

5. The knee joint prosthesis according to claim 1, characterized in that: The tibial plateau (210) and the fixing nail (230) are made of 3D printed titanium alloy powder. The tibial plateau (210) is used as a base on the tibial side. The tibial plateau (210) is combined with a trabecular plateau layer (240). The tibial plateau (210) and the trabecular plateau layer (240) are fixed to each other. The fixing nail (230) has a cross-shaped appearance. The trabecular plateau layer (240) is used for short-term fixation. The trabecular plateau layer (240) and The tibial plateau (210) is used for fixed support of the tibial plateau, the outer shape of the fixing wing (220) has a longitudinal texture, the fixing wing (220) is used for short-term fixation, the trabecular reinforcement block (250) is used for fixing the bone ingrowth of the fixing wing (220), the tibial pad (30) is made of highly cross-linked vitamin E, the tibial pad (30) and the tibial plateau (210) are connected, and the tibial pad (30) is used for the friction interface of the femoral component surface (180).

6. A knee joint prosthesis according to any one of claims 1 to 5, characterized in that: A method for preparing a tibial pad (30) comprises the following steps: S1. Raw material selection: titanium alloy powder is used, which requires good fluidity and uniform particle size distribution; S2, 3D printing, using CAD to build an accurate three-dimensional model, using electron beam 3D printing technology to melt and solidify the titanium alloy powder layer by layer according to the set parameters; S3, hot isostatic pressing treatment, placing the printed parts in hot isostatic pressing equipment and processing them at 920℃ and 100Mpa; S4, annealing treatment, annealing at 800℃ to eliminate residual stress, optimize crystal structure and enhance comprehensive performance.

7. A knee joint prosthesis according to claim 5, characterized in that: The material preparation in S1 includes the following steps: selecting titanium alloy powder 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 the 3D printing process.

8. A knee joint prosthesis according to claim 7, characterized in that: The 3D printing molding in S2 includes the following steps: S201. Using computer-aided design (CAD) technology, accurately construct a three-dimensional model of the femoral condyle body according to the physiological structure and mechanical performance requirements of the human femoral condyle and the overall design standards of the knee joint prosthesis; S202. Use electron beam 3D printing technology to evenly spread the selected titanium alloy powder on the printing platform. Focus the electron beam on the powder layer, and melt and solidify the powder layer by layer according to the preset scanning path and energy parameters.

9. A knee joint prosthesis according to claim 8, characterized in that: The hot isostatic pressing treatment in S3 includes the following steps: placing the printed femoral condyle body into a hot isostatic pressing device, and treating it for a period of time under a high temperature of 920° C. and a high pressure of 100 MPa, so that the tiny pores and defects in the femoral condyle body will be compacted and repaired.

10. The knee joint prosthesis according to claim 8, characterized in that: The annealing treatment in S4 comprises the following steps: After the hot isostatic pressing treatment, the femoral condyle body is annealed by heating it to 800°C and maintaining it for a certain period of time, followed by slow cooling to eliminate the residual stress generated during the 3D printing and hot isostatic pressing process.

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