Interbody fusion cage and preparation method thereof

Abstract

The invention relates to the technical field of medical instruments, and particularly discloses an interbody fusion cage and a preparation method thereof.The preparation method comprises the following steps that S1, a mold matched with the interbody fusion cage in shape is prepared, and a porous aluminum filling body is prepared; s2, the two ends of the mold are filled with porous aluminum material filling bodies, and cavities are formed between the mold and the porous aluminum material filling bodies at the two ends; s3, the mold is filled with PEEK in an injection molding mode, and the cavity and pores of the porous aluminum material filling body are filled with the PEEK; and S4, after the PEEK is cured, removing the mold, and dissolving the porous aluminum filling body by adopting a pickling mode, so that porous PEEK is formed at the two ends of the interbody fusion cage. The porous PEEK structure is prepared in an injection molding mode, and the problem that the technical difficulty is large due to the fact that the porous PEEK structure is prepared in a 3D printing mode is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an intervertebral fusion cage and a preparation method thereof. Background Art

[0002] Intervertebral fusion cage is a common medical implant prosthesis used for bone integration and plays a key role in bone graft fusion.

[0003] The materials of intervertebral fusion devices mainly include aluminum and PEEK polymer (polyetheretherketone). Among them, aluminum can be prepared into a porous structure through 3D printing technology. Its 3D printing is relatively easy and it is hydrophilic. However, the elastic modulus of aluminum is very different from that of human bones. Therefore, the mechanical properties of aluminum are very different from those of human bones. Although the elastic modulus of PEEK polymer is similar to that of human bones, that is, the two have similar mechanical properties, it is very difficult to prepare it into a porous material using 3D printing technology. When preparing PEEK structures, the existing technology has prepared dense PEEK structures by injection molding. For example, CN 202210821456.9 discloses a biomimetic intervertebral fusion device and its preparation method, which discloses the use of injection molding to form PEEK injection-molded parts, and finally connect the PEEK injection-molded parts with porous alloy parts. The dense PEEK polymer surface is hydrophobic, which is not conducive to bone fusion. Therefore, CN 202210821456.9 is achieved by setting a porous alloy component at the end of the PEEK injection-molded component. However, the mechanical properties of the alloy are very different from those of human bones and are not ideal bone fusion materials.

[0004] Therefore, in order to enhance the bone integration effect of the intervertebral fusion cage, the intervertebral fusion cage needs to adopt a porous structure, at least the two ends of the intervertebral fusion cage (the ends in contact with the bone) should be porous structures.

[0005] CN 202323307790.1 discloses a PEEK porous lumbar intervertebral fusion device, which includes: a solid frame and a porous structure fixed within the solid frame. The porous structure provides adhesion and growth space for osteoblasts, guides bone growth, enhances the bone integration effect of the intervertebral fusion device, and solves the problems of loosening and poor stability of the intervertebral fusion device. That is, this technology uses a method of combining a porous PEEK structure within a solid PEEK frame to prepare an intervertebral fusion device. However, the method of preparing the PEEK porous lumbar intervertebral fusion device is to integrate the solid frame and the porous structure through 3D printing. It is very difficult and expensive to prepare PEEK polymer into a porous material through 3D printing: the current mainstream PEEK 3D printing technology is divided into two routes: FDM and SLS. For the FDM technical route, the printing accuracy and stability are poor, internal defects are prone to occur during the molding process, and the compression, shear, and torsional fatigue performance of the intervertebral fusion device after long-term implantation is difficult to guarantee. The SLS process, however, has a minimum feature size of approximately 1mm, while the wire diameter of porous intervertebral fusion devices typically does not exceed 0.5mm, making it difficult to achieve a reasonable porous structure design. Furthermore, the raw materials used in this process cost approximately 10,000 yuan per kilogram, and laser sintering causes powder aging, resulting in low material recycling rates and high costs. Summary of the Invention

[0006] The purpose of the present invention is to provide an intervertebral fusion cage and a preparation method thereof, which adopts injection molding to prepare a porous PEEK structure, thereby avoiding the technical difficulty caused by using 3D printing to prepare a porous PEEK structure.

[0007] The present invention is achieved through the following technical solutions: A method for preparing an intervertebral fusion cage comprises the following steps: S1. Prepare a mold that matches the shape of the intervertebral fusion cage and prepare a porous aluminum filling body; S2. Filling porous aluminum fillers at both ends of the mold to form a cavity between the mold and the porous aluminum fillers at both ends; S3, filling the mold with PEEK by injection molding, so that the PEEK fills the cavity and the pores of the porous aluminum filler; S4. After the PEEK solidifies, the mold is removed and the porous aluminum filler is dissolved by pickling to form porous PEEK at both ends of the intervertebral fusion cage.

[0008] The existing technology usually uses 3D printing technology when preparing porous materials. However, for PEEK, using 3D printing technology to prepare porous materials is very difficult and not easy to achieve. When preparing PEEK structures in the existing technology, there is a method of preparing dense PEEK structures through injection molding. However, the dense PEEK polymer surface is hydrophobic, which is not conducive to bone fusion. The original intention of the present invention is to solve the problem that it is difficult to 3D print porous materials with PEEK polymers and that the hydrophobic surface of PEEK polymers is not conducive to bone fusion.

[0009] The porous aluminum filler prepared by the present invention is the key to forming a porous PEEK structure by injection molding. The porous aluminum filler can be obtained by 3D printing technology. First, the material of the porous aluminum filler is aluminum, which has a relatively high melting point of about 660°C, which meets the condition that it will not be dissolved by the hot-melt PEEK during the injection molding process; secondly, the porous aluminum filler is a porous structure, which meets the condition that the hot-melt PEEK can be filled into the pores of the porous structure during the injection molding process, laying the foundation for the formation of a porous PEEK structure; thirdly, aluminum can react with acid, and the aluminum can be dissolved by pickling after injection molding, and a porous PEEK structure can be formed after the aluminum is dissolved.

[0010] In addition, the porous aluminum filler has a certain hardness, which can meet the requirements of assembly with the mold by interference fit, so as to avoid the need for additional support parts, which may cause unnecessary holes in the prepared intervertebral fusion device after the support parts are removed, affecting the mechanical properties of the intervertebral fusion device.

[0011] In summary, the present invention is based on the concept of injection molding. By designing a mold and a porous aluminum filler that match the intervertebral fusion device with a porous PEEK structure at both ends, and coordinating the injection molding process and the pickling process, the preparation of an intervertebral fusion device with a porous PEEK structure at both ends is achieved. This can solve the problem that the hydrophobic surface of the dense PEEK structure is not conducive to bone fusion, and can avoid the technical difficulty caused by using 3D printing to prepare the porous PEEK structure.

[0012] In a preferred embodiment, in step S1, a porous aluminum filler is provided at each end of the mold, and the porous aluminum filler is evenly arranged with pores or the porous aluminum filler is alternately arranged with pores and through holes.

[0013] In a preferred embodiment, in step S1, a plurality of porous aluminum material filling bodies are provided at each end of the mold, and two adjacent porous aluminum material filling bodies are separated by a partition.

[0014] That is, the specific shape of the porous PEEK structure at both ends of the intervertebral fusion cage prepared by the present invention is not limited, as long as the porosity is sufficient to solve the problem that the hydrophobic surface of the dense PEEK structure is not conducive to bone fusion and bone fusion can be achieved.

[0015] In a preferred embodiment, in step S2, the thickness of the porous aluminum filler is 1-2 mm, and the length of the cavity is 8-9 mm.

[0016] In a preferred embodiment, in step S3, during injection molding, PEEK enters the cavity from the side of the mold where the cavity is provided, and then flows toward the porous aluminum filler on both sides until the PEEK fills the cavity and the pores of the porous aluminum filler.

[0017] The above-mentioned injection molding method of the present invention moves from the middle to both sides. Since the cavity is larger than the pores, the hot-melt PEEK can quickly fill the cavity. Then, under the action of pressure, the hot-melt PEEK enters the pores and fills the pores, thereby ensuring the successful preparation of porous PEEK.

[0018] In a preferred embodiment, in step S4, the acid used for pickling includes dilute sulfuric acid or dilute hydrochloric acid, wherein the dilute sulfuric acid is a dilute sulfuric acid solution having a mass fraction of less than 70%, and the dilute hydrochloric acid is a hydrochloric acid solution having a mass fraction of less than 35%. Due to the volatility of dilute hydrochloric acid, a dilute sulfuric acid solution is preferably used to dissolve the aluminum.

[0019] Concentrated sulfuric acid may cause PEEK to dissolve. Therefore, the acid used in the pickling method must be dilute sulfuric acid or hydrochloric acid that can only dissolve aluminum but not PEEK.

[0020] In a preferred embodiment, in order to improve the dissolution efficiency of porous aluminum, the sulfuric acid solution may be heated to 50-60°C.

[0021] In a preferred embodiment, the mass fraction of the dilute sulfuric acid solution is 30%-40%, and it is heated to 50-60° C. and then used to dissolve the porous aluminum.

[0022] In a preferred embodiment, in step S4, the pickling method includes directly immersing the intervertebral fusion cage in acid.

[0023] In a preferred embodiment, the method further comprises: S5. The intervertebral fusion cage after acid washing is cleaned with alkaline solution and pure water in sequence, and then dried with dry air flow.

[0024] The intervertebral fusion cage prepared based on the above preparation method includes a dense section and porous sections located on both sides of the dense section.

[0025] In a preferred embodiment, the thickness of the porous section is 1-2 mm, the thickness of the dense section is 7-8 mm, and the porosity of the porous section is 50%-70%.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention can realize the preparation of an intervertebral fusion device with a porous PEEK structure at both ends by designing a matching mold and a porous aluminum filler, as well as an acid washing method. This not only satisfies the matching of the mechanical properties of the intervertebral fusion device and the human bone, but also solves the problem that the hydrophobic surface of the dense PEEK structure is not conducive to bone fusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 Schematic diagram of porous aluminum fillers installed at both ends of the mold in Example 1 of the present invention; Figure 2 A schematic diagram of an intervertebral fusion cage prepared in Example 1 of the present invention; Figure 3 Schematic diagram of a porous aluminum filler in Example 2 of the present invention; Figure 4 Schematic diagram of the mold used in Example 3 of the present invention; Figure 5 The figure is a flow chart of the preparation method of the present invention.

[0028] Markings and corresponding parts names in the accompanying drawings: 1-mold shell; 2-partition plate; 3-injection pipe; 4-sealing plate; 100-dense section; 200-porous section; 300-porous aluminum filler; 301-pore; 302-through hole; 400-cavity. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the examples. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. The embodiments described below are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other examples, well-known structures, materials, or methods are not specifically described to avoid obscuring the present invention. The materials, instruments, and reagents used in the following examples, unless otherwise specified, are commercially available. The techniques used in the examples, unless otherwise specified, are conventional techniques well known to those skilled in the art.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0032] Example 1: like Figure 5 As shown, in order to prepare an intervertebral fusion device that has mechanical properties similar to those of human bones and is conducive to bone fusion, this embodiment provides a method for preparing a porous PEEK structure using an injection molding process, specifically providing a method for preparing an intervertebral fusion device, comprising the following steps: S1. Prepare a mold that matches the shape of the intervertebral fusion cage and prepare a porous aluminum filling body 300.

[0033] In this embodiment, the mold includes a mold shell 1, both ends of the mold shell 1 are open ends, the side wall profile of the mold shell 1 matches the required shape of the intervertebral fusion device, an injection tube 3 is provided in the middle of the side wall of the mold shell 1, and sealing plates 4 are provided at both ends of the mold shell 1. The sealing plates 4 are detachably connected to the ends of the mold shell 1, and can be specifically threaded or bolted. The function of the sealing plates 4 is mainly to limit the porous aluminum filler 300 and the hot-melt PEEK in the subsequent injection molding process to prevent the hot-melt PEEK from flowing out of the porous aluminum filler 300.

[0034] The porous aluminum filling body 300 is made by 3D printing. In this embodiment, the porous aluminum filling body 300 has pores 301 evenly arranged therein.

[0035] S2, fill the two ends of the mold shell 1 with porous aluminum filler 300, the outer wall of the porous aluminum filler 300 and the inner wall of the mold shell 1 are interference fit, so that a cavity 400 is formed between the mold shell 1 and the porous aluminum filler 300 at both ends, and then install the sealing plate 4 at both ends of the mold shell 1; after filling the porous aluminum filler 300, the mold is as follows Figure 1 shown.

[0036] When the porous aluminum filler 300 is filled at both ends of the mold shell 1, the side walls of the porous aluminum filler 300 need to be close to the inner wall of the mold shell 1, and the end face of the porous aluminum filler 300 needs to be close to the sealing plate 4 to avoid the aluminum block being wrapped inside after the PEEK material is injected and unable to react quickly with the acid.

[0037] The interior of the porous aluminum filler 300 is in a completely interconnected porous form, and the pore diameter should be no less than 0.3 mm to prevent PEKK from being unable to effectively fill the internal pores.

[0038] S3. Fill PEEK into the mold by injection molding so that PEEK fills the cavity 400 and the pores 301 of the porous aluminum filler 300; specifically, heat the PEEK to melt it to form hot-melt PEEK, and then inject the hot-melt PEEK into the cavity 400 through the injection tube 3. When the hot-melt PEEK fills the cavity 400, it enters the pores 301 inside the porous aluminum filler 300 on both sides under the action of pressure until the hot-melt PEEK fills the cavity 400 and the pores 301 of the porous aluminum filler 300. That is, in this embodiment, an injection tube 3 is provided in the middle of the side wall of the mold shell 1. During injection molding, the injection method is to move from the middle to both sides. Since the cavity 400 has a larger size than the pore 301, the hot-melt PEEK can quickly fill the cavity 400. Then, under the action of pressure, the hot-melt PEEK enters the pore 301 and fills the pore 301 to ensure the successful preparation of porous PEEK. Moreover, when the cavity 400 is filled with hot-melt PEEK, the hot-melt PEEK exerts pressure on the porous aluminum filler 300 at both ends, ensuring that the ends of the porous aluminum filler 300 are always tightly attached to the sealing plate 4 (close contact without gaps), and the hot-melt PEEK entering the pore 301 in the porous aluminum filler 300 will not flow into the ends of the porous aluminum filler 300, resulting in the porous aluminum filler 300 being wrapped by PEEK after solidification and molding, and the pickling removal of the porous aluminum filler 300 cannot be achieved.

[0039] S4. After the hot-melt PEEK in the mold has solidified and formed, the mold is removed (first remove the sealing plate 4, then apply a thrust to the intervertebral fusion device at one end of the mold shell 1 to separate the intervertebral fusion device from the mold shell 1). Acid pickling is performed to dissolve the porous aluminum filler 300, forming porous PEEK at both ends of the intervertebral fusion device. This embodiment may only be used. The acid pickling method involves immersing the intervertebral fusion device in acid. The acid used is a 30% dilute sulfuric acid solution heated to 50°C. The intervertebral fusion device is immersed in a 50°C, 30% by mass, dilute sulfuric acid solution for 5 minutes. Testing indicates that the aluminum has completely dissolved, forming porous PEEK.

[0040] S5. The intervertebral fusion cage after acid washing is cleaned with alkaline solution and pure water in sequence, and then dried with dry air flow.

[0041] The intervertebral fusion cage prepared in this embodiment is as follows Figure 2 As shown, the intervertebral fusion device comprises a dense section 100 and porous sections 200 located on either side of the dense section 100. The intervertebral fusion device in this embodiment has a left-right diameter of 17 mm, an anteroposterior diameter of 13 mm, and a height / thickness of 10 mm (the thickness of the porous section 200 is 1.5 mm, and the thickness of the dense section 100 is 7 mm). The porous section 200 has a uniform porous structure with a pore size of 473 microns, a wire diameter of 0.54 mm, and a porosity of 66%.

[0042] The mechanical properties of the intervertebral fusion cage prepared in this example are: compression stiffness 6748 N / mm, yield strength 6073 N.

[0043] Only the portions of the fusion cage that contact the vertebral bone at both ends are porous to facilitate bone fusion. Typically, the thickness does not exceed 2 mm. Pores that are too small hinder oxygen supply and nutrient transport, leading to poor osteoblast growth. Pores that are too large hinder cell adhesion and differentiation. Pores between 100 and 1000 microns are ideal for bone ingrowth. The porosity of human cancellous bone is 50% to 90%, and this porosity range is considered optimal for bone growth.

[0044] The change in porosity mainly affects bone ingrowth and has little effect on mechanics. Since the porous structure of the intervertebral fusion cage prepared in this example is within a reasonable range after testing, bone ingrowth data is not provided.

[0045] The main structure of the fusion cage is solid, mainly used to support the vertebral body and is the main load-bearing structure. Its compression performance must meet the corresponding standards, such as: the compression stiffness of the cervical interbody fusion cage is ≥5097 N / mm, and the yield strength is ≥5450 N; the compression stiffness of the thoracic and lumbar interbody fusion cage is ≥5914 N / mm, and the yield strength is ≥6371 N.

[0046] That is, the porosity of the intervertebral fusion device prepared in this embodiment meets the requirements of bone growth, and the mechanical properties meet the requirements of a cervical intervertebral fusion device (Note: The size of the fusion device in this embodiment is close to that of a cervical intervertebral fusion device, and the size can be adjusted when it is necessary to meet the performance requirements of a thoracic and lumbar intervertebral fusion device).

[0047] Example 2: This embodiment is based on the embodiment 1. The difference from the embodiment 1 is that the porous aluminum filler 300 used is different. In this embodiment, Figure 3 As shown, the porous aluminum filler 300 does not have a uniform pore structure, but the porous aluminum filler 300 has pores 301 and through-holes 302 arranged at intervals.

[0048] The porosity of the porous aluminum filler 300 is controlled to be approximately 71% by designing the pore size and wire diameter of the pores 301 .

[0049] Example 3: This embodiment is based on embodiment 1, and differs from embodiment 1 in that: Figure 4 As shown, in this embodiment, a partition plate 2 is provided on the inner wall of the mold shell 1 , and a plurality of porous aluminum material filling bodies 300 can be provided at both ends of the mold shell 1 , and two adjacent porous aluminum material filling bodies 300 are separated by the partition plate 2 .

[0050] Example 4: This embodiment is based on embodiment 1, and differs from embodiment 1 in that: The thickness of the aperture section 200 was increased to 2.0 mm.

[0051] The intervertebral fusion device in this embodiment has a left-right diameter of 17 mm, an anteroposterior diameter of 13 mm, and a height / thickness of 10 mm (the thickness of the porous segment 200 is 2.0 mm, and the thickness of the dense segment 100 is 6 mm). The porous segment 200 has a uniform porous structure with a pore size of 473 μm, a wire diameter of 0.54 mm, and a porosity of 66%.

[0052] The mechanical properties of the intervertebral fusion cage prepared in this example are: compression stiffness 6506 N / mm, yield strength 5726 N.

[0053] That is, compared with Example 1, the total thickness of the intervertebral fusion device prepared in this embodiment remains unchanged at 10 mm, the thickness of the porous section 200 is increased, and the thickness of the dense section 100 is reduced from 7 mm to 6 mm. Under the premise that the pore size, wire diameter, and porosity of the porous PEEK remain unchanged, the mechanical properties of the intervertebral fusion device in this embodiment are reduced compared with Example 1.

[0054] Example 5: This embodiment is based on embodiment 1, and differs from embodiment 1 in that: The thickness of the aperture section 200 was increased to 2.5 mm.

[0055] The intervertebral fusion device in this embodiment has a left-right diameter of 17 mm, an anteroposterior diameter of 13 mm, and a height / thickness of 10 mm (the thickness of the porous segment 200 is 2.5 mm, and the thickness of the dense segment 100 is 5 mm). The porous segment 200 has a uniform porous structure with a pore size of 473 μm, a wire diameter of 0.54 mm, and a porosity of 66%.

[0056] The mechanical properties of the intervertebral fusion cage prepared in this example are: compression stiffness 6214 N / mm, yield strength 5214 N.

[0057] That is, compared with Example 1, the total thickness of the intervertebral fusion device prepared in this embodiment remains unchanged at 10 mm, the thickness of the porous section 200 is increased, and the thickness of the dense section 100 is reduced from 7 mm to 5 mm. Under the premise that the pore size, wire diameter, and porosity of the porous PEEK remain unchanged, the mechanical properties of the intervertebral fusion device in this embodiment are significantly reduced compared with Example 1.

[0058] Example 6: This embodiment is based on embodiment 1, and differs from embodiment 1 in that: The thickness of the aperture section 200 was reduced to 1.0 mm.

[0059] The intervertebral fusion device in this embodiment has a left-right diameter of 17 mm, an anteroposterior diameter of 13 mm, and a height / thickness of 10 mm (the thickness of the porous segment 200 is 1.0 mm, and the thickness of the dense segment 100 is 8 mm). The porous segment 200 has a uniform porous structure with a pore size of 473 μm, a wire diameter of 0.54 mm, and a porosity of 66%.

[0060] The mechanical properties of the intervertebral fusion cage prepared in this example are: compression stiffness 7024 N / mm, yield strength 6382 N.

[0061] That is, compared with Example 1, the total thickness of the intervertebral fusion device prepared in this embodiment remains unchanged at 10 mm, the thickness of the porous section 200 is increased, and the thickness of the dense section 100 is increased from 7 mm to 8 mm. Under the premise that the pore size, wire diameter, and porosity of the porous PEEK remain unchanged, the mechanical properties of the intervertebral fusion device in this embodiment are improved compared with Example 1.

[0062] From the data comparison of Example 1, Example 4-Example 6, it can be seen that: Under the premise that the overall thickness of the fusion device is constant, the thickness of the porous section 200 increases and the thickness of the dense section 100 decreases. The mechanical properties of the fusion device decrease as the thickness of the dense section 100 decreases.

[0063] Comparative Example 1: An intervertebral fusion cage has the same shape and structure as that of Example 1, except that the pore section 200 in this comparative example is made of porous aluminum.

[0064] The porous material used in this comparative example is aluminum. Since the mechanical properties of aluminum are significantly different from those of human bones, the fusion effect between the fusion device prepared in this comparative example and human bones is significantly lower than that of the fusion device prepared with porous PEEK used in Example 1.

[0065] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0066] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology, and are not used to limit the conditions for implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

Claims

1. A method for preparing an intervertebral fusion cage, characterized in that: The steps include: S1, preparing a mold that matches the shape of the intervertebral fusion cage and preparing a porous aluminum filling body (300); S2, filling the porous aluminum material filling body (300) at both ends of the mold, so that a cavity (400) is formed between the mold and the porous aluminum material filling body (300) at both ends; S3, filling PEEK into the mold by injection molding, so that the PEEK fills the cavity (400) and the pores (301) of the porous aluminum material filling body (300); S4. After the PEEK is solidified, the mold is removed, and the porous aluminum filler (300) is dissolved by pickling, so that porous PEEK is formed at both ends of the intervertebral fusion cage.

2. The method for preparing an intervertebral fusion cage according to claim 1, characterized in that: In step S1, one of the porous aluminum fillers (300) is provided at each end of the mold, and the porous aluminum filler (300) is evenly arranged with the pores (301) or the porous aluminum filler (300) is alternately arranged with the pores (301) and through holes (302).

3. The method for preparing an intervertebral fusion cage according to claim 1, characterized in that: In step S1, a plurality of the porous aluminum material filling bodies (300) are provided at each end of the mold, and two adjacent porous aluminum material filling bodies (300) are separated by a partition (2).

4. The method for preparing an intervertebral fusion cage according to claim 1, characterized in that: In step S2, the thickness of the porous aluminum material filling body (300) is 1-2 mm, and the length of the cavity (400) is 8-9 mm.

5. The method for preparing an intervertebral fusion cage according to claim 1, characterized in that: In step S3, during injection molding, the PEEK enters the cavity (400) from the side of the mold where the cavity (400) is provided, and then flows toward the porous aluminum filler (300) on both sides until the PEEK fills the cavity (400) and the pores (301) of the porous aluminum filler (300).

6. The method for preparing an intervertebral fusion cage according to claim 1, characterized in that: In step S4, the acid used in the pickling method includes dilute sulfuric acid or dilute hydrochloric acid, the dilute sulfuric acid is a sulfuric acid solution with a mass fraction of less than 70%, and the dilute hydrochloric acid is a hydrochloric acid solution with a mass fraction of less than 35%.

7. The method for preparing an intervertebral fusion cage according to claim 1, characterized in that: In step S4, the pickling method includes directly soaking the intervertebral fusion cage in acid.

8. The method for preparing an intervertebral fusion cage according to any one of claims 1 to 7, characterized in that: Also includes: S5. The intervertebral fusion cage after acid washing is cleaned with alkaline solution and pure water in sequence, and then dried with dry air flow.

9. An intervertebral fusion cage prepared by the preparation method according to any one of claims 1 to 8, characterized in that: It comprises a dense section (100) and pore sections (200) located on both sides of the dense section (100).

10. The intervertebral fusion cage according to claim 9, characterized in that: The thickness of the porous section (200) is 1-2 mm, and the thickness of the dense section (100) is 7-8 mm; the porosity of the porous section (200) is 50%-70%.

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