Personalized biological fixation type tibia implant

Abstract

The utility model discloses a personalized biological fixation type tibia implant which comprises a tibia wing 400, a tibia support 200, a tibia support boss 100, a tibia support groove 300 and a tibia stem 500. The tibia support boss and the tibia support groove are located on the top face of the tibia support. The tibia wing and the tibia stem are located at the lower end of the tibia support, and the tibia wing and the tibia stem are integrally formed by finite element porous structures; the tibia wings are located on the left side and the right side of the front portion of the tibia stem, the bottom faces of the tibia wings are connected with the tibia support, and the side faces of the tibia wings are connected with the tibia stem. A finite element porous structure is adopted, the density and distribution of finite element grid division can be adjusted according to actual requirements, and optimal distribution of force is achieved. And the stress is more uniform. Due to the fact that the personalized biological fixation type tibia implant is designed through the parametric modeling method, the porous structure in the model does not need to be redesigned and can be changed only by adjusting input parameters, and the design efficiency can be greatly improved.

Description

Technical Field

[0001] The utility model relates to the design field of biological fixation type implants, in particular to a personalized biological fixation type tibial implant. Background Art

[0002] Due to bone diseases, bone trauma, congenital malformations and other reasons, it cannot be used normally, seriously affecting people's physical and mental health, and even endangering their lives, so it needs to be repaired or replaced through surgery. At present, most of the implants used in domestic surgeries are imported products from abroad, and the degree of matching and similarity with the Chinese race is low. Therefore, it is urgent to research and develop personalized medical implants suitable for Chinese people. During use, solid implants cause "stress shielding" because their hardness is greater than that of surrounding tissues, which is not conducive to stimulating the growth of surrounding tissues. In addition, solid implants are not conducive to the growth of surrounding tissues due to the lack of pores, and are easy to loosen after implantation. Therefore, when the mechanical properties and wear resistance requirements of the implantation site are not high, the implant part can be made into a porous structure.

[0003] Personalized biological fixation implants have gradually begun to be used because of their good biocompatibility, excellent mechanical properties, and low loosening rate after implantation. However, the existing modeling of personalized biological fixation tibial implants is mostly based on first designing a porous structure and then performing Boolean operations with the solid tibial implant. The molding method uses traditional casting, which has the disadvantages of poor mechanical properties of the molded parts, low design efficiency, poor biocompatibility, easy loosening, and difficult molding.

[0004] The previous design of groove plus porous structure is not conducive to customization due to its position being restricted by the groove, and the mesh density cannot be adjusted. At the same time, due to the limitation of the groove structure during filling, the force on the filled part of the porous structure is not uniform. Utility Model Content

[0005] In order to overcome the above-mentioned defects of the prior art, the utility model provides a personalized biological fixation type tibial implant.

[0006] The technical solution of this utility model is as follows:

[0007] A personalized biological fixation tibial implant comprises a tibial wing 400, a tibial tray 200, a tibial tray boss 100, a tibial tray groove 300, and a tibial stem 500, wherein the tibial tray boss and the tibial tray groove are located on the top surface of the tibial tray; the tibial wing and the tibial stem are located at the lower end of the tibial tray, and the tibial wing and the tibial stem are integrally formed by a finite element porous structure; the tibial stem is columnar, the tibial wing is located on the left and right sides of the front part of the tibial stem, the bottom surface of the tibial wing is connected to the tibial tray, and the side surface is connected to the tibial stem; the finite element porous structure of the tibial wing and the tibial stem has a triangular or square pore shape or a mixture of a triangular and a square pore shape; the tibial wing, the tibial tray, the tibial tray boss, and the tibial stem are integrally formed by metal 3D laser printing in one-time printing; the finite element porous structure is connected by longitudinal, transverse, and oblique pillars.

[0008] Furthermore, the shape of the pillars of the finite element porous structure of the tibial wing and the tibial stem is set according to actual needs and can be square or cylindrical.

[0009] Furthermore, the connection between one node and other nodes in the finite element porous structure is not restricted and can be one-to-one or one-to-many.

[0010] Furthermore, the pore shape of the finite element porous structure can be a triangle, a square, or a mixture of a triangle and a square.

[0011] Furthermore, the pore size range of the finite element porous structure of the tibial wing and tibial stem is 50μm-1000um; the diameter range of the pillar is 80μm-1000um.

[0012] Furthermore, the pillars of the finite element porous structure are square or circular.

[0013] Technical effects and advantages of the utility model:

[0014] The finite element porous structure can be used to adjust the density and distribution of the finite element mesh according to actual needs, achieving the optimal distribution of force. The force is more uniform. Since the parametric modeling method is used to design a personalized biological fixation tibial implant, the change of the porous structure in the model does not need to be redesigned, and only the input parameters need to be adjusted, which can greatly improve the design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the biological fixation type tibial implant in the patent of the present invention.

[0016] Figure 2 This is the front view of the biological fixation type tibial implant in the patent of the present invention.

[0017] Figure 3 It is a stereoscopic diagram of the biological fixation type tibial implant in the patent of the present invention.

[0018] Figure 4 This is the design and 3D printing flow chart of the biological fixation tibial implant in the patent of this invention. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Selective Laser Melting (SLM) technology, also known as "metal 3D printing technology", is a cutting-edge technology in additive manufacturing. It uses a focused laser beam with a diameter of 30 to 50 microns to melt metal or alloy powder layer by layer, and accumulate it into a metallurgically bonded and densely organized entity, thereby obtaining metal functional parts of almost any shape with complete metallurgical bonding.

[0021] like Figure 1 and Figure 2 As shown, the biological fixation type tibial implant is formed by controlling the laser beam to selectively melt the paved layers of metal powder according to the cross-sectional profile data of the tibial implant through a metal 3D laser printing device, and gradually stacking them; the personalized biological fixation type tibial implant includes a tibial tray boss 100, a tibial tray 200, a tibial tray groove 300, a tibial wing 400, and a tibial stem 500; the tibial wing 400 and the tibial stem 500 are finite element porous structures; in the finite element porous structures of the tibial wing 400 and the tibial stem 500, the porosity, the average pore size and the surface area to volume ratio can be set according to actual needs; in the finite element porous structures of the tibial wing 400 and the tibial stem 500, the shape of the pillars can be set according to actual needs, and a square or cylindrical shape is adopted; in the finite element porous structures of the tibial wing 400 and the tibial stem 500, the pore shape can be either triangular or square.

[0022] The precision of the 3D printed personalized biological fixation tibial implant can be controlled within 100 μm.

[0023] In the method of establishing a porous structure using the finite element method, the generating position of the porous structure is not affected by the complexity of the parts and can be arbitrarily designed according to actual needs.

[0024] The shape and size of the porous structure in the biological fixation type tibial implant can be set according to actual needs, and the pore size range is 50 μm-1000 μm; the diameter range of the pillar is 80 μm-1000 μm.

[0025] In order to achieve good biocompatibility of biological fixation tibial implants and prevent implant loosening, the personalized biological fixation tibial implant designed by the parametric modeling method uses finite element analysis software to perform force analysis on the personalized tibial implant model, and can also sort the nodes according to the elastic modulus of the bone tissue around the implant site, optimize the model structure, avoid "stress shielding", and the change of the porous structure in the model does not need to be redesigned, but only needs to adjust the input parameters to complete, which can greatly improve the design efficiency; due to the use of the parametric modeling method, the porosity, average pore size, and surface area to volume ratio can be directly adjusted by adjusting the input parameters to achieve the optimal biocompatibility of the biological fixation tibial implant, prevent the tibial implant from loosening, and greatly extend the service life of the tibial implant.

[0026] like Figure 4 As shown, the design and preparation method of the biological fixation type tibial implant specifically includes the following steps:

[0027] Step A00: The doctor scans the patient's body through CT or MRT to obtain slice data;

[0028] Step B00: Import the slice data into mimics software, perform threshold segmentation, and further subdivide the unconnected segmented areas on the initial threshold segmentation mask into subgroups by region growing to generate a new mask. Finally, perform smoothing, denoising and other operations to obtain the reconstructed 3D model;

[0029] Step C00: Import the reconstructed point cloud model into Geomagic Studio to simulate bone cutting, extract the contour surface of the affected part, and complete the forward design in other 3D software;

[0030] Step D00: Import the three-dimensional solid model completed by forward design into the finite element analysis software Autodesk Simulation Mechanical for force analysis. According to the force distribution of the model, sort the nodes to achieve the optimal distribution of force, optimize the model structure, and adjust the density and distribution of the finite element mesh.

[0031] Step E00: Export the post-processing results of the structurally optimized tibia geometry from the Autodesk Simulation Mechanical software platform in the form of an Excel spreadsheet text to extract the mesh node position information of the model.

[0032] Step F00: Use the Grasshopper plug-in of Rhinoceros to read the Excel spreadsheet text, and according to the characteristics of the tibial implant model, write a battery diagram program to generate lines from points, and generate bodies from lines, and finally realize the three-dimensional modeling of the biological fixation tibial implant.

[0033] Step G00: Slice and layer the obtained three-dimensional solid model, perform path planning, import it into a 3D metal printing device, and complete the forming.

[0034] Step H00: Judge the magnitudes of n and N. If n < N, execute Step D00; if n = N, execute Step G00.

[0035] Step I00: Execute Step F00.

[0036] Step J00: After printing is completed, a bio-fixed tibial implant meeting the requirements is obtained.

[0037] Wherein, n ≤ N.

[0038] In order to improve the forming quality, the powder raw material needs to be filtered and dried before being added to the powder cylinder: the powder raw material is filtered through a vibrating screen to remove impurities in the powder raw material; then the powder raw material is dried to reduce the oxygen content of the powder raw material.

[0039] In this embodiment, the powder raw material can enter the printing area from the laser printing device through a powder feeding form or a powder spraying form.

[0040] In order to ensure the finished product quality of the bio-fixed tibial implant, the bio-fixed tibial implant prepared by the above laser 3D printing preparation method needs to undergo annealing, sandblasting, electrolytic polishing, and mirror polishing treatments. After the formed bio-fixed tibial implant undergoes the above treatments, it can be used after disinfection.

[0041] In this embodiment, the powder raw material uses titanium alloy powder.

[0042] By adopting the laser printing method, the structure of the bio-fixed tibial implant of the present invention is no longer restricted by process conditions, and a bio-fixed tibial implant with any structure can be manufactured. It can directly manufacture bio-fixed tibial implants with complex curved surfaces and complex pores; due to being prepared by the laser printing method, the pore shape of the porous structure in the bio-fixed tibial implant is no longer restricted, and the porous structure can be designed into triangular pores or square pores or a mixture of triangular and square. Due to being prepared by the laser printing method, the shape of the struts of the porous structure in the bio-fixed tibial implant is no longer restricted and can be square or cylindrical. Due to using finite element analysis software to perform stress analysis on the personalized tibial implant model, the nodes can be sorted according to the elastic modulus of the bone tissue around the implantation site, and the model structure can be optimized. Therefore, "stress shielding" is avoided, the biocompatibility of the tibial implant is improved, loosening of the tibial implant is prevented, and the service life of the prosthesis is greatly extended.

[0043] Since the finite element analysis software is used to analyze the force of the personalized tibial implant model, the nodes are sorted according to the force distribution of the model, the model structure is optimized, and the density and distribution of the finite element mesh division are adjusted to achieve the optimal distribution of force. Since the parametric modeling method is used to design the personalized biological fixed tibial implant, the change of the porous structure in the model does not need to be redesigned, and only the input parameters need to be adjusted to complete, which can greatly improve the design efficiency; since the parametric modeling method is used, the porosity, average pore size, and surface area to volume ratio can be adjusted directly by adjusting the input parameters to achieve the optimal biocompatibility of the biological fixed tibial implant. Since the 3D printing method is used, the structure of the biological fixed tibial implant is no longer restricted by the process conditions, and the biological fixed implants with complex curved surfaces and complex pores can be directly manufactured; since the laser 3D printing method is used to prepare the biological fixed tibial implant, the shape of the pillar and the pore are no longer restricted. The pillar can be round or square, and the pore shape can be triangular or square or a mixture of triangular and square. Through parametric modeling and SLM direct molding of implants, the design efficiency can be greatly improved and the purpose of directly manufacturing personalized implants can be achieved, which is of great significance to improving the service life of implants and the quality of life of patients.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A personalized biological fixation tibial implant, characterized in that: It includes a tibial wing, a tibial tray, a tibial tray boss, a tibial tray groove, and a tibial stem. The tibial tray boss and the tibial tray groove are located on the top surface of the tibial tray; the tibial wing and the tibial stem are located at the lower end of the tibial tray, and the tibial wing and the tibial stem are formed as a whole by a finite element porous structure; the tibial stem is columnar, the tibial wing is located on the left and right sides of the front part of the tibial stem, the bottom surface of the tibial wing is connected to the tibial tray, and the side surface is connected to the tibial stem; the pore shape of the finite element porous structure of the tibial wing and the tibial stem is a triangle, a square pore shape or a mixture of a triangle and a square; the tibial wing, the tibial tray, the tibial tray boss, and the tibial stem are a metal 3D laser printed one-time printing molding structure as a whole; the finite element porous structure is connected by longitudinal, transverse and oblique pillars.

2. A personalized biological fixation tibial implant according to claim 1, characterized in that: The shape of the pillars of the tibial wing and tibial stem finite element porous structure is set according to actual needs and can be square or cylindrical.

3. The personalized biological fixation tibial implant according to claim 1, characterized in that: The pore shape of the finite element porous structure is triangle or square or a mixture of triangle and square.

4. The personalized biological fixation tibial implant according to claim 1, characterized in that: The pore size range of the finite element porous structure of the tibial wing and the tibial stem is 50 μm-1000 μm; the diameter range of the pillar is 80 μm-1000 μm.

5. The personalized biological fixation tibial implant according to claim 1, characterized in that: The pillars of the finite element porous structure are square or circular.

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