阅读说明：本技术 椎体假体的加工方法 (Processing method of vertebral prosthesis ) 是由 石小龙 魏崇斌 邹达 于 2020-12-25 设计创作，主要内容包括：本发明提供了一种椎体假体的加工方法包括：得到包含椎体的模型和椎间盘的模型的第一组合结构并获取第一应力分布和第一平均位移；建立选定材质的孔隙率和弹性模量之间的函数关系；根据函数关系得到多个弹性模量,并得到多个第二组合结构并获取第二应力分布和第二平均位移。比较第一应力分布与每个第二应力分布,比较第一平均位移和每个第二平均位移,确定椎体假体最终模型,并得到椎体假体最终模型的弹性模量；将椎体假体最终模型的弹性模量带入函数关系中,得到最终孔隙率,进而得到椎体假体。本申请的技术方案有效地解决了相关技术中的椎体假体模型的调整过程复杂,设计难度较大的问题。(The invention provides a processing method of a vertebral prosthesis, which comprises the following steps: obtaining a first composite structure comprising a model of a vertebral body and a model of an intervertebral disc and obtaining a first stress distribution and a first average displacement; establishing a functional relationship between the porosity and the elastic modulus of the selected material; and obtaining a plurality of elastic moduli according to the functional relation, obtaining a plurality of second combined structures and obtaining a second stress distribution and a second average displacement. Comparing the first stress distribution with each second stress distribution, comparing the first average displacement with each second average displacement, determining a final model of the vertebral body prosthesis, and obtaining the elastic modulus of the final model of the vertebral body prosthesis; and (4) bringing the elastic modulus of the final model of the vertebral body prosthesis into the functional relation to obtain the final porosity, and further obtaining the vertebral body prosthesis. The technical scheme of the application effectively solves the problems that the adjustment process of the vertebral prosthesis model in the related technology is complex and the design difficulty is high.)

1. A method of machining a vertebral prosthesis, comprising:

step S10: obtaining a first composite structure comprising a model of a vertebral body (10) and a model of an intervertebral disc (20);

step S20: acquiring a first stress distribution and a first average displacement of the first combined structure;

step S30: establishing a functional relationship between the porosity and the elastic modulus of the selected material;

step S40: obtaining a plurality of elastic moduli according to the functional relationship, and obtaining a plurality of second combined structures according to the plurality of elastic moduli, wherein each second combined structure comprises a model of a vertebral body (10) and a middle model of a vertebral body prosthesis, and the middle model of the vertebral body prosthesis is made of the selected material;

step S50: acquiring a second stress distribution and a second average displacement of each second combined structure;

step S60: comparing the first stress distribution with each second stress distribution and comparing the first average displacement with each second average displacement, and when the comparison result of the first stress distribution and one of the second stress distributions and the comparison result of the first average displacement and one of the second average displacements simultaneously meet a first preset condition, determining a centrum prosthesis intermediate model in the second combined structure meeting the first preset condition as a centrum prosthesis final model, and obtaining the elastic modulus of the centrum prosthesis final model;

step S70: and substituting the elastic modulus of the final model of the vertebral body prosthesis into the functional relation to obtain final porosity, and processing according to the final porosity to obtain the vertebral body prosthesis (30).

2. The method of machining a vertebral prosthesis according to claim 1, characterized in that said functional relationship is: 23143n is Y²-46210n + 23043.1; wherein Y is elastic modulus, n is porosity, and n is more than 40% and less than 90%.

3. The method for processing a vertebral prosthesis according to claim 1, wherein said step S10 comprises:

step S11: scanning the lumbar vertebra of a human body by CT;

step S12: -importing the results of the scanning into image processing software resulting in the first composite structure comprising a model of the vertebral body (10) and a model of the intervertebral disc (20).

4. The method of machining a vertebral prosthesis of claim 1 wherein the step of comparing the first and second stress distributions and the first and second average displacements comprises:

and comparing whether the first stress distribution and the second stress distribution meet a second preset condition, and comparing whether the difference value between the first average displacement and the second average displacement meets a third preset condition.

5. The method for processing a vertebral prosthesis according to claim 1, wherein said step S70 comprises:

step S71: hot isostatic pressing the vertebral prosthesis (30);

step S72: placing the vertebral body prosthesis (30) subjected to the hot isostatic pressing treatment into an acetone solution for cleaning, and flushing the vertebral body prosthesis (30) by using purified water after cleaning;

step S73: adding calcium ions, phosphorus ions and strontium ions into deionized water to obtain electrolyte;

step S74: performing micro-arc oxidation treatment in the electrolyte by using stainless steel as a cathode and the vertebral prosthesis (30) washed by purified water as an anode;

step S75: washing the vertebral body prosthesis (30) subjected to the micro-arc oxidation treatment, soaking the washed vertebral body prosthesis (30) in deionized water, and drying the vertebral body prosthesis (30) after soaking.

6. The method for processing the vertebral body prosthesis according to claim 5, wherein the oxidation voltage of the micro-arc oxidation treatment is 200-400V, the output pulse width of a power supply is 40-100 mus, the peak current is set to be 40-200A, and the oxidation time is 2-10 min.

7. The method for processing a vertebral prosthesis according to claim 5, wherein said step S71: the range of the highest temperature of the hot isostatic pressing treatment is 850-880 ℃, the range of the temperature rising speed is 8-10 ℃/min, the medium of the hot isostatic pressing treatment is argon, the range of the highest pressure is 90-100 MPa, the range of the pressure rising speed is 1.0-1.4 MPa/min, and the range of the heat preservation and pressure maintaining time is 0.5-2 hours.

8. The method for processing the vertebral prosthesis according to claim 5, wherein the concentration C of calcium ions is between 0.01mol/L and 0.42mol/L, the relationship between the concentration P of phosphorus ions and the concentration C of calcium ions is P ═ 0.95C +0.07, and the relationship between the concentration S of strontium ions and the concentrations P of phosphorus ions and C of calcium ions satisfies S ═ C + 0.75P.

9. Method for manufacturing a vertebral prosthesis according to claim 5, characterized in that the surface of the vertebral prosthesis (30) is provided with a film containing calcium ions, phosphorus ions and strontium ions, the thickness of said film being between 0.5 μm and 3 μm, the content of calcium ions in said film being: ca ≥ 3 wt.%, content of phosphorus ion: p is more than or equal to 0.5 wt.%, and the content of strontium ions: sr is more than or equal to 0.2 wt.%.

10. The method of machining a vertebral prosthesis according to claim 1, characterized in that the method of machining the vertebral prosthesis (30) comprises one or more of laser stereolithography, selective laser sintering/melting and electron beam melting techniques; the selected material is titanium alloy, and the titanium alloy is Ti-6Al-4V, Ti-6Al-17Nb, Ti-13Nb-13Zr or Ti-5Zr-3Mo-15 Nb.

Technical Field

The invention relates to the technical field of medical instruments, in particular to a machining method of a vertebral prosthesis.

Background

Vertebral body tumors, severe comminuted fractures, and certain inflammations, often cause damage to the vertebral body and may result in spinal cord, nerve damage or collapse of the vertebral body and deformity of the spine. Neurological dysfunction or deformity often requires replacement of a vertebral prosthesis to restore stability to the spine. The replacement of the vertebral body prosthesis can effectively open the intervertebral space, and has important significance for recovering the satisfactory vertebral height, physiological curvature, correcting the flexion deformity and recovering the volume of the vertebral canal.

In clinical vertebral prosthesis replacement, the macroscopic structure of the vertebral prosthesis, such as size, shape and the like, is closely related to nerve injury, implantation stability and long-term fusion effect in the operation. However, because the individual difference of the mechanical environment in the body of the patient is large, the interaction between the standardized, mass-produced and serialized vertebral body prosthesis and the human body is difficult to optimize, and particularly for the osteoporosis patient, the problems of settlement, fatigue failure and the like of the vertebral body prosthesis after being implanted into the body are caused.

In the related art, the design of vertebral body prostheses generally includes the following steps:

1. constructing a finite element model of the spine;

2. carrying out a simulation biomechanics experiment on the constructed finite element model;

3. according to the stress distribution born by the vertebral prosthesis, the size or the position of the vertebral prosthesis is adjusted to obtain the vertebral prosthesis model which best accords with the spinal biomechanics.

In the above steps, the worker can only adjust the vertebral prosthesis model according to experience, which results in a complex adjustment process and a high design difficulty.

Disclosure of Invention

The invention mainly aims to provide a processing method of a vertebral body prosthesis, which aims to solve the problems of complex adjustment process and high design difficulty of a vertebral body prosthesis model in the design of the vertebral body prosthesis in the related technology.

In order to achieve the above object, the present invention provides a method for processing a vertebral prosthesis, comprising: step S10: obtaining a first composite structure comprising a model of a vertebral body and a model of an intervertebral disc; step S20: acquiring a first stress distribution and a first average displacement of a first combined structure; step S30: establishing a functional relationship between the porosity and the elastic modulus of the selected material; step S40: obtaining a plurality of elastic moduli according to the functional relation, and obtaining a plurality of second combined structures according to the plurality of elastic moduli, wherein each second combined structure comprises a vertebral body model and a vertebral body prosthesis intermediate model, and the vertebral body prosthesis intermediate model is made of a selected material; step S50: acquiring a second stress distribution and a second average displacement of each second combined structure; step S60: comparing the first stress distribution with each second stress distribution and comparing the first average displacement with each second average displacement, and when the comparison result of the first stress distribution and one of the second stress distributions and the comparison result of the first average displacement and one of the second average displacements simultaneously meet a first preset condition, determining a centrum prosthesis intermediate model in a second combined structure meeting the first preset condition as a centrum prosthesis final model, and obtaining the elastic modulus of the centrum prosthesis final model; step S70: and (4) bringing the elastic modulus of the final model of the vertebral body prosthesis into the functional relation to obtain final porosity, and processing according to the final porosity to obtain the vertebral body prosthesis.

Further, the functional relationship is: 23143n is Y²-46210n + 23043.1; wherein Y is elastic modulus, n is porosity, and n is more than 40% and less than 90%.

Further, step S10 includes: step S11: scanning the lumbar vertebra of a human body by CT; step S12: the results of the scan are imported into image processing software to obtain a first composite structure comprising a model of the vertebral body and a model of the intervertebral disc.

Further, the step of comparing the first and second stress distributions and the first and second average displacements comprises: and comparing whether the first stress distribution and the second stress distribution meet a second preset condition, and comparing whether the difference value between the first average displacement and the second average displacement meets a third preset condition.

Further, step S70 includes: step S71: carrying out hot isostatic pressing treatment on the vertebral prosthesis; step S72: placing the vertebral prosthesis subjected to the hot isostatic pressing treatment into an acetone solution for cleaning, and washing the vertebral prosthesis by using purified water after cleaning; step S73: adding calcium ions, phosphorus ions and strontium ions into deionized water to obtain electrolyte; step S74: performing micro-arc oxidation treatment in electrolyte by using stainless steel as a cathode and using the vertebral prosthesis washed by purified water as an anode; step S75: washing the vertebral body prosthesis after micro-arc oxidation treatment, soaking the washed vertebral body prosthesis in deionized water, and drying the vertebral body prosthesis after soaking.

Further, the oxidation voltage of the micro-arc oxidation treatment is 200-400V, the output pulse width of the power supply is 40-100 mus, the peak current is set to be 40-200A, and the oxidation time is 2-10 min.

Further, step S71: the highest temperature range of the hot isostatic pressing treatment is 850-880 ℃, the temperature rising speed range is 8-10 ℃/min, the medium of the hot isostatic pressing treatment is argon, the highest pressure range is 90-100 MPa, the pressure rising speed range is 1.0-1.4 MPa/min, and the heat preservation and pressure maintaining time range is 0.5-2 hours.

Further, the calcium ion concentration C is between 0.01mol/L and 0.42mol/L, the relationship between the phosphorus ion concentration P and the calcium ion concentration C is P ═ (0.95C +0.07), and the relationship between the strontium ion concentration S and the phosphorus ion concentration P and the calcium ion concentration C satisfies S ═ C + 0.75P.

Further, a film layer containing calcium ions, phosphorus ions and strontium ions is formed on the surface of the vertebral body prosthesis, the thickness of the film layer is between 0.5 and 3 μm, and the content of the calcium ions in the film layer is as follows: ca ≥ 3 wt.%, content of phosphorus ion: p is more than or equal to 0.5 wt.%, and the content of strontium ions: sr is more than or equal to 0.2 wt.%.

Further, the processing method of the vertebral body prosthesis comprises one or more of laser stereolithography, selective laser sintering/melting and electron beam melting technology; the vertebral body prosthesis is made of titanium alloy, wherein the titanium alloy is Ti-6Al-4V, Ti-6Al-17Nb, Ti-13Nb-13Zr or Ti-5Zr-3Mo-15 Nb.

By applying the technical scheme of the invention, the functional relation between the porosity and the elastic modulus is obtained, so that the steps are simplified in the whole design process of the vertebral prosthesis, and after the elastic modulus of the final model of the vertebral prosthesis is obtained, the functional relation is substituted to obtain the final porosity, thereby reducing the processing difficulty. And the overall effect of the vertebral body prosthesis can be improved. Therefore, the technical scheme of the application effectively solves the problems that in the design of the vertebral prosthesis in the related technology, the adjustment process of the vertebral prosthesis model is complex and the design difficulty is high.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic flow chart diagram illustrating an embodiment of a method of manufacturing a vertebral prosthesis according to the present invention;

FIG. 2 shows a detailed flow chart of step S10 of the method of machining the vertebral body prosthesis of FIG. 1;

FIG. 3 is a detailed flow chart of step S70 of the method of manufacturing the vertebral prosthesis of FIG. 1;

FIG. 4 is a perspective view of a vertebral body and an intervertebral disc of the method of manufacture of the vertebral body prosthesis of FIG. 1;

FIG. 5 is a perspective view of another perspective of the vertebral bodies and intervertebral discs of the method of manufacture of the vertebral body prosthesis of FIG. 4;

FIG. 6 is a perspective view of a vertebral body and vertebral body prosthesis of the method of manufacture of the vertebral body prosthesis of FIG. 1;

FIG. 7 is a perspective view of another perspective of the vertebral body and vertebral body prosthesis of the method of manufacture of the vertebral body prosthesis of FIG. 6;

FIG. 8 is a schematic view of a first stress distribution in the method of manufacturing the vertebral prosthesis of FIG. 1;

FIG. 9 illustrates a second stress distribution diagram during the method of manufacturing the vertebral prosthesis of FIG. 1;

FIG. 10 is a schematic diagram illustrating functional relationships in a method of manufacturing the vertebral prosthesis of FIG. 1;

FIG. 11 is a schematic view of the porous structure of the vertebral prosthesis of FIG. 1 during the method of manufacturing the vertebral prosthesis; and

fig. 12 shows a schematic representation of the topography of the surface film layer of the vertebral prosthesis of fig. 1 during the method of manufacturing the vertebral prosthesis.

Wherein the figures include the following reference numerals:

10. a vertebral body; 20. an intervertebral disc; 30. a vertebral prosthesis.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

At present, the invention patent with the patent number of CN111281613A provides a bionic porous artificial vertebral body processing method based on 3D printing of PEEK, but the design and the manufacture of a vertebral body prosthesis in an osteoporosis state are not solved, and particularly, PEEK is a biological inert material, has no biological activity and cannot play a role in resisting osteoporosis. Meanwhile, the pore structure proposed in the patent is a parameter in the PEEK material state, and does not provide a corresponding parameter for the porous titanium alloy implant material. The invention patent with the patent number of CN110495951A provides a method for manufacturing a personalized lumbar vertebra oblique lateral approach reduction model, so as to achieve the purposes of the size and the shape of a fusion cage planned before an operation and the prediction of the postoperative lumbar vertebra reduction condition, but does not relate to the manufacture, the mechanical adaptation and the functionalization of a 3D printing titanium alloy vertebral body prosthesis. The invention patent with patent number CN109766599A provides a personalized anterior vertebral prosthesis design method based on the bone reconstruction principle, but does not provide specific prosthesis design and manufacture for mechanical adaptation, and does not solve the bioactive function of the vertebral prosthesis. In view of the above problems, the technical solution of this embodiment provides a method for processing a vertebral body prosthesis, which is to design a macroscopic structure of the vertebral body prosthesis to fit a human mechanical environment, and mainly establishes a functional relationship between porosity and elastic modulus, so as to simplify the whole design process through the functional relationship. And the centrum prosthesis meeting the design requirements is printed through additive manufacturing, and hot isostatic pressing treatment is carried out, so that the mechanical property of the porous centrum prosthesis is improved. Then, the vertebral prosthesis is subjected to biological functionalization treatment, so that the implanted vertebral prosthesis has good biomechanical adaptation, bone tissue induction and osteoporosis resistance with human bone tissues.

As shown in fig. 1 and fig. 4 to 8, in the present embodiment, the processing method of the vertebral prosthesis includes:

step S10: a first composite structure comprising a model of the vertebral body 10 and a model of the intervertebral disc 20 is obtained.

Step S20: acquiring a first stress distribution and a first average displacement of a first combined structure; finite element analysis of the first composite structure may result in a first stress distribution, and measurements of the model of the vertebral body 10 and the model of the intervertebral disc 20 may result in a first average displacement.

Step S30: a functional relationship between the porosity and the elastic modulus of the selected material is established. In this step, for the selected material, a plurality of porosities are selected, elastic moduli corresponding to the plurality of porosities one to one are obtained, and a functional relationship between the porosity and the elastic modulus is obtained. Specifically, a range of porosity is selected based on empirical values, with a plurality of points, such as 6 points (40%, 50%, 60%, 70%, 80%, and 90%), being selected within the range. The middle model of the vertebral body prosthesis is made of the selected material, and the selected material is of a porous structure. The compression experiment can be carried out through the hydraulic experiment objective table, the size of the porous structure is not changed, the elastic modulus of the porous structure under different porosities is tested, and the function relation expression of the elastic modulus and the porosity of the porous structure is obtained by fitting a curve with Origin software (function drawing software).

Step S40: and obtaining a plurality of elastic moduli according to the functional relation, and obtaining a plurality of second combined structures according to the plurality of elastic moduli, wherein each second combined structure comprises a model of the vertebral body 10 and a middle model of the vertebral body prosthesis, and the middle model of the vertebral body prosthesis is made of the selected material. Obtaining a plurality of elastic modulus measuring bodies according to the functional relation means that: and selecting the value range of the porosity according to the functional relationship to obtain the corresponding value range of the elastic modulus. A plurality of elastic moduli are selected within the value range according to a certain difference. The plurality of second composite structures comprise a plurality of centrum prosthesis intermediate models, and the plurality of centrum prosthesis intermediate models are designed according to a plurality of elastic moduli.

Step S50: and acquiring a second stress distribution and a second average displacement of each second combined structure. And carrying out finite element analysis on each second combined structure in sequence to obtain a plurality of second stress distributions, and measuring the model of the vertebral body 10 and the plurality of middle models of the vertebral body prosthesis to obtain a plurality of second average displacements.

Step S60: and comparing the first stress distribution with each second stress distribution and comparing the first average displacement with each second average displacement, and when the comparison result of the first stress distribution and one of the second stress distributions and the comparison result of the first average displacement and one of the second average displacements simultaneously meet a first preset condition, determining a centrum prosthesis intermediate model in the second combined structure meeting the first preset condition as a centrum prosthesis final model, and obtaining the elastic modulus of the centrum prosthesis final model. The comparison will be described in detail below.

Step S70: and (3) substituting the elastic modulus of the final model of the vertebral body prosthesis into the functional relation to obtain final porosity, and processing according to the final porosity to obtain the vertebral body prosthesis 30.

By applying the technical scheme of the embodiment, the functional relationship between the porosity and the elastic modulus is obtained, so that the steps are simplified in the whole design process of the vertebral prosthesis, after the elastic modulus of the final model of the vertebral prosthesis is obtained, the functional relationship is introduced to obtain the final porosity, and the processing difficulty is further reduced. And the overall effect of the vertebral body prosthesis can be improved. Therefore, the technical scheme of the embodiment effectively solves the problems that in the design of the vertebral prosthesis in the related technology, the adjustment process of the vertebral prosthesis model is complex and the design difficulty is high.

As shown in fig. 1 and 8, in the present embodiment, the function relationship is: 23143n is Y²-46210n + 23043.1; wherein Y is elastic modulus, n is porosity, and n is more than 40% and less than 90%. The range of porosity values is selected by empirical values. The establishment of the functional relation effectively reduces the difficulty of the design of the vertebral body prosthesis, can save the design time and further can effectively improve the efficiency. The process of validating the functional relationship can be seen in fig. 8. Obtaining a plurality of porosities according to empirical values, obtaining the elastic modulus corresponding to each porosity through a compression experiment, and fitting a curve by Origin software (function drawing software) to obtain a functional relation expression of the elastic modulus and the porosity of the porous structure.

As shown in fig. 1 and 2, in the present embodiment, step S10 includes: step S11: scanning the lumbar vertebra of a human body by CT; step S12: the results of the scan are imported into image processing software resulting in a first composite structure comprising a model of the vertebral body 10 and a model of the intervertebral disc 20. Carrying out CT scanning on the lumbar vertebrae of the segment L3-L4-L5 of the patient suffering from osteoporosis, then importing the vertebra original data obtained by the CT scanning into a mix image processing software, reconstructing the three-dimensional structure of the upper, middle and lower segments of the vertebral body 10 needing to be implanted into the vertebral body prosthesis 30, and obtaining a three-dimensional vertebral body model, namely the model of the vertebral body 10 and the model of the intervertebral disc 20. The three-dimensional vertebral body model is carried out through UG software. The grids of the first combined structure and the second combined structure are divided in 3-matic software, and tetrahedral units are adopted for the grids of the vertebral body 10, the intervertebral disc 20, the vertebral body prosthesis 30 and the fixing device; loads were applied to vertebral body 10 (i.e., the upper endplate of L3) using 400N; the material properties of the vertebral body 10 are assigned on the mimics software according to a gray scale and density, elastic modulus and poisson ratio mathematical model, and the disc material properties can be assigned according to empirical values. This results in a first stress distribution and a first average displacement for the first composite structure and a second stress distribution and a second average displacement for the second composite structure. Of course, the vertebral bodies, intervertebral discs, vertebral body prostheses, and fixation device grids described above may also take the form of hexahedral cells or other forms.

As shown in fig. 4 to 7, in the present embodiment, the step of comparing the first and second stress distributions and the first and second average displacements includes: and comparing whether the first stress distribution and the second stress distribution meet a second preset condition, and comparing whether the difference value between the first average displacement and the second average displacement meets a third preset condition. The second predetermined condition is to determine whether the first stress distribution and the second stress distribution are the same. That is, in the mechanical analysis software, the color of the first stress distribution cloud picture and the color of the second stress distribution cloud picture are observed, if the colors of the corresponding regions are basically the same, the second preset condition is judged to be met, and if the colors of the corresponding regions are obviously different, the second preset condition is judged to be not met. The third preset condition is to judge whether the first average displacement and the second average displacement are the same. And when the second preset condition is met but the third preset condition is not met, the first preset condition is not met. And when the second preset condition is not met but the third preset condition is met, the first preset condition is not met. And when the second preset condition is not met and the third preset condition is not met, the first preset condition is not met. And only when the second preset condition and the third preset condition are both met, the first preset condition meets the conditions, and under the conditions, the centrum prosthesis intermediate model can be determined to be the centrum prosthesis final model.

In fig. 6 and 7, fig. 6 shows a cloud of finite element distributions of vertebral bodies and intervertebral discs, and fig. 7 shows a cloud of finite element distributions of prosthetic bodies of vertebral bodies and vertebral bodies. In the comparison, it is compared whether the color in the upper box in fig. 6 and the color in the upper box in fig. 7 are the same. Meanwhile, it is compared whether the color in the lower box in fig. 6 and the color in the lower box in fig. 7 are the same.

At present, research shows that strontium element has obvious influence on in vivo bone metabolism, and strontium can inhibit bone resorption and promote bone formation. Therefore, the strontium salt has double effects of bone resorption resistance and bone formation improvement, and after a large amount of experimental studies are carried out on the utilization of strontium, the inventor successfully forms a strontium-containing film layer on the surface of the vertebral body prosthesis, so that the bone tissue induction capability and the osteoporosis resistance capability of the vertebral body prosthesis are effectively improved.

As shown in fig. 1 and 3, in the present embodiment, step S70 includes: step S71: hot isostatic pressing of the vertebral prosthesis 30; step S72: placing the vertebral body prosthesis 30 subjected to the hot isostatic pressing treatment into an acetone solution for cleaning, and flushing the vertebral body prosthesis 30 by using purified water after cleaning; step S73: adding calcium ions, phosphorus ions and strontium ions into deionized water to obtain electrolyte; step S74: using stainless steel as a cathode, and using the centrum prosthesis 30 washed by purified water as an anode, and carrying out micro-arc oxidation treatment in electrolyte; step S75: washing the vertebral body prosthesis 30 after micro-arc oxidation treatment, soaking the washed vertebral body prosthesis 30 in deionized water, and drying the vertebral body prosthesis 30 after soaking. Through the hot isostatic pressing treatment, the tissue density and the fatigue performance of the vertebral prosthesis 30 can be effectively improved. Thereby effectively improving the fatigue strength and the long-term service safety of the vertebral prosthesis 30. The steps S72 to S75 are surface modification operations of the vertebral prosthesis 30, which are performed to change the surface properties of the blank of the vertebral prosthesis 30, so that the surface of the vertebral prosthesis 30 is made of a bioactive substance, and the vertebral prosthesis 30 can be better connected with the bone structure of a human body after being implanted into the human body, thereby achieving biological fixation. Specifically, in this embodiment, the temperature of the deionized water is 30 ℃, and at this time, the properties of the calcium ions, the phosphorus ions, and the strontium ions can be ensured, and the above temperature ranges can ensure the original properties of the calcium ions, the phosphorus ions, and the strontium ions. The calcium ion is selected from calcium acetate, the phosphorus ion is selected from sodium glycerophosphate, and the strontium ion is selected from strontium acetate. Of course, the calcium ion can also be selected from one or more of calcium chloride, calcium dihydrogen phosphate, calcium glycerophosphate, calcium citrate, calcium lactate and calcium oxide; the phosphorus ions can also be selected from one or more of sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium hexametaphosphate and sodium polyphosphate; the strontium ions may also be selected from strontium hydroxide. The above substances are common in the chemical field and are readily available. After the electrolyte is prepared, EDTA-2Na is added into the electrolyte to serve as a complexing agent, and the mixture is stirred uniformly by a stirrer.

As shown in fig. 1 to 3 and fig. 9 and 10, in the present embodiment, the oxidation voltage of the micro-arc oxidation process is between 200V and 400V, the output pulse width of the power supply is between 40 μ s and 100 μ s, the peak current is set between 40A and 200A, and the oxidation time is between 2min and 10 min. The temperature of the electrolyte in the micro-arc oxidation treatment process is controlled between 30 ℃ and 45 ℃. The conditions are set so that the surface of the vertebral prosthesis body forms a bioactive layer with calcium ions and phosphorus ions, and a functional layer with strontium ions and resisting osteoporosis is formed. Specifically, in this embodiment, the oxidation voltage is 280V, the output pulse width of the power supply is 60 μ s, the peak current is 100A, the oxidation time is 5min, and the temperature of the electrolyte during the micro-arc oxidation treatment is 36 ℃.

As shown in fig. 1 and 3 and fig. 9 and 10, in the present embodiment, step S71: the highest temperature range of the hot isostatic pressing treatment is 850-880 ℃, the temperature rising speed range is 8-10 ℃/min, the medium of the hot isostatic pressing treatment is argon, the highest pressure range is 90-100 MPa, the pressure rising speed range is 1.0-1.4 MPa/min, and the heat preservation and pressure maintaining time range is 0.5-2 hours. The inventors have obtained the above data after a number of experiments. The highest temperature range is 850-880 ℃, the temperature rise speed range is 8-10 ℃/min, the medium for hot isostatic pressing treatment is argon, the highest pressure range is 90-100 MPa, the pressure rise speed range is 1.0-1.4 MPa/min, the heat preservation and pressure maintaining time range is 0.5-2 hours, the hot isostatic pressing treatment effect can be ensured, and the vertebral prosthesis has good mechanical properties. Specifically, in this example, the maximum temperature of the hot isostatic pressing treatment was 860 ℃, the medium of the hot isostatic pressing treatment was argon, the maximum pressure was 95MPa, the heat and pressure retention time was 1 hour, the pressure increase rate was 1.2MPa/min, and the temperature increase rate was 9 ℃/min.

As shown in fig. 1 to 3, in the present embodiment, the calcium ion concentration C is between 0.01mol/L and 0.42mol/L, the relationship between the phosphorus ion concentration P and the calcium ion concentration C is (0.95C +0.07), and the relationship between the strontium ion concentration S and the phosphorus ion concentration P and the calcium ion concentration C satisfies S ═ C + 0.75P. After the concentration of calcium ions is determined, the concentration of phosphorus ions and the concentration of strontium ions are continuously adjusted. And obtaining the ratio relation of the calcium ions and the phosphorus ions and the ratio relation of the calcium ions, the phosphorus ions and the strontium ions, and obtaining the concentration of the calcium ions, the concentration of the phosphorus ions and the concentration of the strontium ions respectively through the ratio relations.

As shown in fig. 1 to 3, in the present embodiment, a film layer containing calcium ions, phosphorus ions and strontium ions is formed on the surface of the vertebral prosthesis 30, the thickness of the film layer is between 0.5 μm and 3 μm, and the content of calcium ions in the film layer is as follows: ca ≥ 3 wt.%, content of phosphorus ion: p is more than or equal to 0.5 wt.%, and the content of strontium ions: sr is more than or equal to 0.2 wt.%. The contents of calcium ions, phosphorus ions and strontium ions effectively ensure that the surface of the vertebral prosthesis has bioactivity and osteoporosis resistance.

As shown in fig. 1-3 and 9 and 10, in the present embodiment, the machining process of the vertebral prosthesis 30 includes one or more of laser stereolithography, selective laser sintering/melting, and electron beam melting techniques; the vertebral body prosthesis 30 is made of titanium alloy, and the titanium alloy is one of Ti-6Al-4V, Ti-6Al-17Nb, Ti-13Nb-13Zr or Ti-5Zr-3Mo-15 Nb. The vertebral prosthesis 30 is a porous structure including one or more of an amorphous pore structure, a cubic structure, a hexagonal prism structure, a diamond structure, a rhombohedral structure, a truncated octahedral structure, and a trabecular bone structure.

Specifically, the patient standing position L2-L3 segment lumbar vertebrae is subjected to CT scanning, and then vertebra original data obtained by the CT scanning are imported into a mix image processing software, so that the three-dimensional structures of the upper and lower vertebral bodies 10 in which the vertebral body prosthesis 30 needs to be implanted are reconstructed, and a three-dimensional vertebral body model is obtained. The geometric characteristic data of the three-dimensional model comprises the surface contour and the intervertebral space height of the upper vertebral body and the lower vertebral body, an intervertebral disc middle model inosculated with the upper vertebral body and the lower vertebral body is reconstructed by UG software, and the height of the upper vertebral body and the lower vertebral body is 11.5mm of the average height of the intervertebral space. Meshing is carried out in 3-matic software, and tetrahedral units or hexahedral units are adopted by the meshes of the vertebral body 10, the intervertebral disc 20, the vertebral body prosthesis 30 and the fixing device; load was applied to the superior vertebral body using 400N; the vertebral body material properties are assigned on the mimics software according to a grey scale and density, elastic modulus and poisson's ratio mathematical model, and the material properties of the intervertebral disc 20 can be assigned to finite element models of the vertebral body 10 and the intervertebral disc 20 and finite element models of the vertebral body 10 and the vertebral body prosthesis 30 according to empirical values. The vertebral body prosthesis 30 and fixation device were implanted in a simulated fashion on 3-matic software according to an average height of the intervertebral space of 11.5 mm. According to stress analysis carried out on abaqus software, a stress distribution diagram of the vertebral body 10 and the intervertebral disc 20 is obtained, and the average displacement of the upper vertebral body is output; stress profiles of vertebral body 10 and vertebral body prosthesis 30, the point of maximum stress being at the location where vertebral body prosthesis 30 is in contact with the superior vertebral body; under the condition of not changing other parameters, the elastic modulus of the vertebral body prosthesis 30 is continuously adjusted, the calculation result is compared with the finite element simulation result of the vertebral body 10 and the intervertebral disc 20, the most appropriate value of the elastic modulus of the vertebral body prosthesis 30 is selected, and then the corresponding rigidity value is obtained. According to the optimal elastic modulus optimized by finite element simulation, the elastic modulus is brought into a functional relation corresponding to the porosity and the elastic modulus, so that the porosity of the vertebral body prosthesis 30 is obtained, and the rigidity value of the 3D printed vertebral body prosthesis 30 is verified by an experimental method; manufacturing the vertebral prosthesis 30 using an additive manufacturing process; data of the vertebral body prosthesis 30 that meets the design requirements is input to the additive manufacturing apparatus according to the design requirements. The manufacturing method of the vertebral body prosthesis can be one or more of laser stereolithography, selective laser sintering/melting and electron beam melting technology. The titanium alloy is one of Ti-6Al-4V, Ti-6Al-17Nb, Ti-13Nb-13Zr or Ti-5Zr-3Mo-15 Nb. The porous structure of the vertebral prosthesis 30 may be one or more of an amorphous pore structure, a cubic structure, a hexagonal prism structure, a diamond structure, a rhombic dodecahedron structure, a truncated octahedral structure, and a trabecular bone structure; hot isostatic pressing of the printed vertebral prosthesis 30: so as to improve the compactness and the fatigue performance of the centrum prosthesis 30 manufactured by additive manufacturing. And performing micro-arc oxidation treatment on the obtained vertebral body prosthesis 30 to finally obtain the vertebral body prosthesis 30 with mechanical adaptation, bone tissue induction and osteoporosis resistance.

Fig. 11 shows a specific structure of the porous structure; fig. 12 shows the specific structure of the membrane layer of the surface of the vertebral prosthesis 30.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.