An interbody fusion device and its preparation method

Abstract

This invention provides an interbody fusion device, comprising: a shell and a vertebral lamina, wherein the height of the shell is not less than the height of the vertebral lamina, and an accommodating chamber is formed between the shell and the vertebral lamina. The vertebral lamina is symmetrically arranged vertically and vertically, and is provided with a first slide rail and a second slide rail, as well as a vertical groove and an annular groove. The vertebral lamina has a multi-layer design, with a first vertebral lamina and a second vertebral lamina respectively arranged from the inside out; a transmission device, comprising a first lifting column and a second lifting column, both of which have reverse threads on their outer surfaces; and a stop device, which is sleeved on the aforementioned first and second lifting columns and consists of a dovetail protrusion and a dovetail groove; and a driving device, comprising a retaining ring, a support rod, a support block, and a support groove. The retaining ring is detachably connected to the support rod and placed in the annular groove, and the support rod is inserted into the support groove and fixedly connected to the support block. The technical solution of this application can effectively solve the problem of damage to autologous bone caused by the surface of the prosthesis during surgery.

Description

Technical Field

[0001] This invention relates to the field of orthopedic implants, specifically to an interbody fusion device. Background Technology

[0002] Spinal fusion is the gold standard surgical procedure for treating intervertebral disc degeneration, spondylolisthesis, instability, and certain types of fractures. The core objective of this surgery is to restore the normal height of the intervertebral space at the affected segment, reconstruct the physiological curvature and stability of the spine, and provide a supportive environment for eventual bony fusion by implanting an intervertebral fusion cage. A successful fusion surgery highly depends on achieving long-term, stable, and robust osseointegration between the fusion cage and the host bone.

[0003] To promote osseointegration, the design concept of modern fusion devices has evolved from early dense, smooth solid structures (such as Peek materials) to biomimetic porous metal structures. In particular, titanium alloy fusion devices fabricated using additive manufacturing technologies such as electron beam melting (EBM) or selective laser melting (SLM) can form a precisely controlled, interconnected three-dimensional porous mesh structure internally. This trabecular-like structure has the following significant advantages: First, its elastic modulus is closer to that of autologous cancellous bone, effectively reducing stress shielding effects and lowering the risk of long-term fusion device subsidence; second, its high porosity of 60%-80% provides an unparalleled three-dimensional space for osteoblast migration, proliferation, and differentiation, greatly accelerating the speed and quality of new bone ingrowth and significantly improving the fusion rate.

[0004] However, this porous structure, designed to optimize long-term biological performance, presents severe and unforeseen challenges for immediate surgical implantation. The high surface roughness and large coefficient of friction inherent in porous structures mean that during the percussion implantation of the fusion cage through a narrow surgical channel, its rough surface exerts significant shear and scraping forces on the cartilaginous endplates, which are crucial to both the upper and lower surfaces of the vertebral body. The cartilaginous endplate is a thin but tough layer of cartilage covering the cancellous bone of the vertebral body. It acts as a barrier, protecting the underlying bone from damage and fulfilling the critical function of nutrient exchange between the intervertebral discs. Iatrogenic endplate injury has become one of the most prominent complications during the implantation of porous fusion cages. This injury triggers a series of cascading clinical problems: increased surgical risk: scratching the endplate exposes the underlying highly vascularized cancellous bone, leading to increased unnecessary intraoperative bleeding, interference with the surgical field, and prolonged operation time. Basis for fusion failure: Damaged endplates lose their load-bearing barrier function. Under the continuous axial stress after surgery, the fusion cage is more likely to sink into the vertebral body, i.e., subsidence. Subsidence leads to loss of intervertebral disc height, changes in the physiological curvature of the spine, and may even compress nerve roots, ultimately causing surgical failure. Impact on long-term efficacy: Damage to the endplate may further affect the metabolic environment of the intervertebral disc. Although the fused segment itself is no longer mobile, the risk of degeneration in adjacent segments may increase as a result.

[0005] Currently, surgeons often rely on experience-based, forceful tapping when facing implantation resistance. This not only places extremely high demands on the surgeon's feel and control but also makes the surgical process highly uncertain: insufficient tapping force may lead to poor fusion cage placement; excessive force or directional deviation can directly exacerbate endplate damage. Some compromise solutions exist, such as spraying a smooth coating of hydroxyapatite (HA) or titanium nitride onto the key contact areas of the porous fusion cage, or designing a streamlined shape. However, these methods are essentially compromises: the coating may wear down or degrade in the long term, hindering bone ingrowth; and shape optimization has little effect on reducing drag on extremely rough porous surfaces. None of these solutions fundamentally resolve the inherent contradiction between "low friction during implantation" and "high long-term bone integration." Summary of the Invention

[0006] The purpose of this invention is to provide an interbody fusion device and its preparation method to solve the technical problem of iatrogenic endplate damage to the human body during the implantation of the interbody fusion device.

[0007] To address the aforementioned problems, this invention provides an intervertebral fusion device and its preparation method, specifically comprising: a shell and a vertebral lamina, wherein the height of the shell is not less than the height of the vertebral lamina, a receiving chamber is formed between the shell and the vertebral lamina, the vertebral lamina is symmetrically arranged vertically, a first slide rail and a second slide rail are provided on the vertebral lamina, and a vertical groove and an annular groove are also provided, the vertebral lamina is a multi-layer design, with a first vertebral lamina and a second vertebral lamina respectively arranged from the inside out; a transmission device, comprising a first lifting column and a second lifting column, both of which are provided with reverse threads on their outer surfaces, the transmission device also includes a stop device, the stop device is sleeved on the aforementioned first lifting column and second lifting column, the stop device is composed of a dovetail protrusion and a dovetail groove, and the internal of the stop device is provided with threads of different directions that mesh with the aforementioned reverse threads; a driving device, comprising a retaining ring, a support rod, a support block, and a support groove, the retaining ring and the support rod are detachably connected and placed in the annular groove, the support block is provided with a non-penetrating support groove, and the support rod is inserted into the support groove and fixedly connected to the support block.

[0008] Furthermore, multiple injection holes are provided at the top and bottom of the shell, with the injection holes positioned slightly higher than the vertebral plate, through which low freezing point liquids are injected into the shell.

[0009] Furthermore, low freezing point liquids are water, physiological saline, antibacterial drugs, or mixtures thereof.

[0010] Furthermore, the first lamina is a solid structure, while the second lamina is a porous structure resembling bone trabeculae.

[0011] Furthermore, the interbody fusion device also includes a third lamina, which is a smooth ice-like structure formed by a low freezing point liquid, wherein the third lamina is in contact with autologous bone.

[0012] Furthermore, the first vertebral lamina is made of a cobalt-chromium-molybdenum alloy, and the second vertebral lamina is made of a titanium alloy.

[0013] Furthermore, the retaining ring and the support rod, as well as the support rod and the support groove, are detachably connected by magnetic attraction.

[0014] The present invention also provides a method for manufacturing the above-mentioned intervertebral fusion device, comprising the following steps: S1: Integrated additive manufacturing step: using electron beam melting or selective laser melting technology, a first lamina as an inner layer structure is integrally printed using cobalt-chromium-molybdenum alloy powder, and a second lamina with a porous structure as an outer layer structure is printed using titanium alloy powder on the outside of the first lamina, so that the first lamina and the second lamina form a metallurgical bond at the interface; S2: Post-processing step: the fusion device lamina printed in step S1 is subjected to hot isostatic pressing and surface finishing; S3: Third lamina formation step: a low freezing point liquid is injected into a accommodating cavity communicating with the second lamina, and the low freezing point liquid is solidified on the outer surface of the second lamina by conducting low temperature to form a temporary smooth ice layer of the third lamina.

[0015] Applying the technical solution of this invention, since the height of the shell is not less than the height of the vertebral plate, a receiving cavity is formed between the shell and the vertebral plate. At this time, the vertebral plate is located in the middle of the shell, and the vertebral plates are symmetrically arranged vertically. The vertebral plates are provided with a first slide rail and a second slide rail for placing two transmission devices diagonally opposite each other. Vertical grooves and annular grooves are also provided, allowing the transmission devices to push the upper and lower vertebral plates to move vertically, and also adjusting the horizontal movement of the transmission devices. The vertebral plates have a multi-layer design, with a first vertebral plate and a second vertebral plate respectively arranged from the inside out. The transmission device includes a first lifting column and a second lifting column. The outer surface is provided with reverse threads. The transmission device also includes a stop device, which is sleeved on the aforementioned first and second lifting columns. During the rotation of the stop device, the first and second lifting columns move vertically. The stop device consists of dovetail protrusions and dovetail grooves. The internal part of the stop device is provided with threads of different directions that mesh with the aforementioned reverse threads. The driving device includes a retaining ring, a support rod, a support block, and a support groove. The retaining ring and the support rod are detachably connected and placed in the annular groove. The support block is provided with a non-penetrating support groove. The support rod is inserted into the support groove and fixedly connected to the support block. With the above configuration, rotating the retaining ring causes the retaining ring to rotate, which in turn causes the support rod to rotate, thereby causing the first and second lifting columns to move up and down, bringing the upper and lower vertebral plates close to the outer surface of the shell and reducing the volume of the accommodating chamber. At this time, the porous structure has not yet contacted the bone surface. After reaching the preset position, the two support rods fixed to the adjacent stop devices are pulled out. Then, the two opposing support rods are moved to move the transmission device, so that the dovetail protrusions and dovetail grooves on both sides fit together. Finally, the retaining ring is put back to complete the fixation. Therefore, the technical solution of this invention can effectively prevent iatrogenic endplate damage to the human body during interbody fusion device implantation. It fundamentally resolves the inherent contradiction between "low friction during implantation" and "high bone integration over the long term." Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0017] Figure 1 An external view of the interbody fusion device is shown;

[0018] Figure 2 An exploded view of the internal structure of the interbody fusion device is shown.

[0019] Figure 3 A top view of the lamina is shown;

[0020] Figure 4 A cross-sectional view of the transmission device is shown;

[0021] Figure 5 A cross-sectional view of the drive unit is shown;

[0022] Figure 6 A cross-sectional view of the lamina is shown;

[0023] The above-mentioned figures include the following reference numerals: 10, shell; 101, injection hole; 102, accommodating chamber; 20, vertebral lamina; 201, first vertebral lamina; 202, second vertebral lamina; 203, third vertebral lamina; 204, first slide rail; 205, second slide rail; 206, vertical groove; 207, annular groove; 30, transmission device; 301, first lifting column; 302, second lifting column; 303, stop device; 3031, dovetail protrusion; 3032, dovetail groove; 304, reverse thread; 40, drive device; 401, retaining ring; 402, support rod; 403, support block; 4031, support groove. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Any specific values ​​in all examples shown and discussed herein should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0027] like Figure 1 As shown: An intervertebral fusion device includes: a housing 10, with multiple through injection holes 101 provided at both the upper and lower parts of the housing; a vertebral lamina 20, the position of which is slightly lower than that of the housing, so that a receiving chamber 102 is formed between the two; and the position of the injection holes 101 is slightly higher than that of the vertebral lamina 20.

[0028] like Figure 2-5 As shown: The intervertebral fusion device has a first slide rail 204 and a second slide rail 205 on the vertebral lamina 20, as well as a vertical groove 206 and an annular groove 207. The vertebral lamina 20 has a multi-layer design, with a first vertebral lamina 201 and a second vertebral lamina 202 arranged from the inside out. The transmission device 30 includes a first lifting column 301 and a second lifting column 302, both of which have reverse threads 304 on their outer surfaces. The transmission device also includes a stop device 303, which is sleeved on the first lifting column. On the lowering column 301 and the second rising column 302, the stopping device consists of a dovetail protrusion 3031 and a dovetail groove 3032; the driving device 40 includes a retaining ring 401, a support rod 402, a support block 403, and a support groove 4031. The retaining ring 401 is detachably connected to the support rod 402 and placed in the annular groove 207. The support block has a non-penetrating support groove 4031 inside, and the support rod 402 is inserted into the support groove 4031 and fixedly connected to the support block 403. The retaining ring 401 and the support rod 402, and the support rod 402 and the support groove 4031 are all detachably connected by magnetic attraction.

[0029] In use, the transmission device 30 is first placed on the first slide rail 204 and the second slide rail 205, with a total of two transmission devices. In the initial state, the two transmission devices are located diagonally opposite each other in the intervertebral fusion device. Then, one end of the four support rods 402 is inserted into the support groove 4031 of the support block 403, and the other end is connected to the retaining ring by magnetic attraction. Then, the retaining ring is rotated, and the four support rods will rotate in the annular groove 207, thereby driving the stop device to rotate. Since the stop device has threads in opposite directions inside, which mesh with the reverse threads on the outer surfaces of the first and second lifting columns, the first and second lifting columns will extend in the vertical direction, and the first and second vertebral lamina will also extend in the vertical direction. After reaching the preset position, the adjacent support rods of the two stop devices are removed, leaving the opposing support rods. Then, the support rods are moved through the vertical groove to bring the two transmission devices closer to the center of the intervertebral fusion device until the dovetail protrusions and dovetail grooves of the two stop devices match. This approach yields the following beneficial effects: the porous structure of the second lamina, being slightly lower than the shell surface and adjustable, eliminates the risk of bone damage during implantation. During the critical implantation phase, its outer surface exhibits a temporary, extremely smooth, low-friction state, ensuring successful, zero-damage implantation to the ideal position. After implantation, it quickly and reliably transforms back into its original bio-friendly porous surface, seamlessly integrating and efficiently promoting bone ingrowth. This solution perfectly resolves the core contradictions in current clinical practice, possessing significant clinical implications and market value.

[0030] like Figure 6 As shown, the lamina comprises a three-layer structure. The innermost layer is a solid structure made of cobalt-chromium-molybdenum alloy, forming the first lamina 201. The middle layer is a porous structure made of titanium alloy, resembling bone trabeculae, forming the second lamina 202. The third layer is a smooth ice layer structure formed by a low-freezing-point liquid, which is the third lamina 203. The third lamina is in contact with human bone. This design reduces the instantaneous friction during implantation because the third lamina is a smooth ice surface. Furthermore, the porous structure of the second lamina, resembling bone trabeculae, effectively improves long-term bone integration.

[0031] To better form a complete third lamina, the following types of low freezing point liquids can be used:

[0032] Sterile water: The purest choice, with a freezing point of 0°C. Physiological saline, with an osmotic pressure consistent with human body fluids, is the safest and most standard choice, avoiding osmotic pressure shocks to cells. Balanced salt solutions (BSS): Such as Duchenne phosphate-buffered saline (DPBS) and Ringer's solution. They not only provide osmotic pressure but also contain ions such as glucose, calcium, potassium, and magnesium, better maintaining cell viability and reducing potential impacts on surrounding tissues, making them superior to ordinary physiological saline. Lactated Ringer's solution: Closer to plasma electrolyte composition and contains sodium lactate as a buffer, resulting in a more stable pH.

[0033] Adding specific functional substances to the above solution creates a composite solution, allowing the third lamina (ice layer) to exert its therapeutic effect both before and after thawing. Antibacterial / Anti-infective agents: Antibiotics: such as vancomycin, tobramycin, gentamicin, etc. Released directly at the surgical site to prevent postoperative infection. Antimicrobial peptides: A novel type of antibacterial agent that is less likely to induce drug resistance. Osteogenesis / Bone Induction Agents: BMPs (bone morphogenetic proteins): such as BMP-2, BMP-7. Currently the most potent bone-inducing growth factors, greatly accelerating and enhancing bone integration between the vertebral body and the fusion cage. Osteogenic peptides: Smaller molecules that stimulate bone formation. Anti-resorption drugs such as denosumab: Can be used to inhibit osteoclast activity, particularly suitable for patients with osteoporosis. Analgesics / Anti-inflammatory Agents: Local anesthetics: such as bupivacaine. Slowly released after the ice layer melts, providing significant analgesia for 48-72 hours postoperatively, reducing the use of opioids. Nonsteroidal anti-inflammatory drugs (NSAIDs): such as ketorolac. Reduce postoperative inflammation and pain. Steroids: such as dexamethasone. Powerful anti-inflammatory, but should be used with caution to avoid affecting bone healing. Imaging contrast agents: such as gadopentetate dimeglumine (for MRI) or iohexol (for CT). Make the ice layer around the fusion cage visible on images, allowing the surgeon to confirm the integrity, smoothness, and uniform thickness of the ice layer during intraoperative fluoroscopy and monitor the ice melting process postoperatively.

[0034] The present invention also includes a method for preparing a vertebral lamina, specifically as follows: The preparation of the first vertebral lamina 201 and the second vertebral lamina 202 is achieved through the following steps:

[0035] S1: 3D Model Design and Printing: Using computer-aided design (CAD) software, based on the anatomical parameters of the target vertebral body, a solid 3D model of the first lamina 201 and a porous 3D model of the second lamina 202 are constructed. The porous structure model of the second lamina 202 requires preset porosity, pore size, and wire diameter parameters to simulate the natural trabecular bone structure. The final integrated digital model is then imported into electron beam melting (EBM) or selective laser melting (SLM) metal 3D printing equipment.

[0036] S2: Substrate preparation and printing: The first vertebral lamina 201 uses medical-grade cobalt-chromium-molybdenum (CoCrMo) alloy powder as the printing material. This material has high strength and wear resistance, making it suitable for load-bearing core structures. The second vertebral lamina 202 uses medical-grade titanium alloy (Ti6Al4V ELI) powder, whose excellent biocompatibility and elastic modulus are more conducive to bone ingrowth. Under an inert gas protective environment, the metal powder is melted layer by layer by high-energy electron beam or laser for integrated printing, so that the first vertebral lamina (1) and the second vertebral lamina (2) are metallurgically bonded at the interface to form a solid integral structure.

[0037] S3: Post-processing: After printing, the support structure is removed, and the printed part is then subjected to hot isostatic pressing (HIP) to eliminate internal residual stress and close any micropores that may have been generated during printing, significantly improving its mechanical properties and fatigue life. Finally, surface finishing processes such as sandblasting and electropolishing are performed to remove adhering powder and burrs, obtaining the final product.

[0038] In-situ formation method of the third lamina: The third lamina 203 is not a prefabricated solid component, but a temporary functional surface generated in situ before and during surgical implantation through the following steps:

[0039] S4: Preoperative cleaning and pretreatment: Before surgery, the fusion device body (i.e., the shell structure containing the first and second lamina) is placed in a low-temperature environment (approximately 4°C) for cooling. Sterile, low-freezing-point liquid such as physiological saline or a solution containing antibacterial drugs is injected into the accommodating chamber 102 through the pre-set injection port 101 on the shell 10, so as to fully wet the porous structure of the second lamina 202 and ensure that no air bubbles remain in the chamber.

[0040] S5: Intraoperative instantaneous cryoforming: Before the implantation procedure, a specialized operating tool pre-frozen to ultra-low temperature (such as -196°C liquid nitrogen or -78°C dry ice) is brought into contact with the drive device 40 or stop device 303 of the fusion device to conduct cold energy. The low temperature is rapidly transferred to the entire outer surface of the fusion device through the highly thermally conductive metal first lamina 201 and second lamina 202, causing the liquid wetting the porous outer layer of the second lamina 202 and the accommodating chamber 102 to instantly freeze, forming a smooth and solid ice layer structure on the outer surface of the second lamina 202, which is the third lamina 203.

[0041] S6: Postoperative Melting and Functional Transition: After the fusion cage is precisely implanted into the ideal position in the intervertebral space, heat from the surrounding human tissue (approximately 37°C) is continuously conducted to the fusion cage. Under the influence of body temperature, the icy structure of the third lamina 203 gradually melts, returning to a liquid state. This liquid is partially absorbed through the porous structure of the second lamina 202 or is exuded in small amounts through the injection port 101 and then metabolized normally by the body. At this point, the inherent porous structure of the second lamina 202 is fully exposed, directly contacting the vertebral endplate and immediately beginning to exert its biological function of promoting bone ingrowth.

[0042] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0043] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0044] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An interbody fusion device, characterized in that, include: The shell and the vertebral lamina are provided. The height of the shell is not less than the height of the vertebral lamina. An accommodating cavity is formed between the shell and the vertebral lamina. The vertebral lamina is symmetrically arranged vertically and vertically. The vertebral lamina is provided with a first slide rail and a second slide rail, as well as a vertical groove and an annular groove. The vertebral lamina is a multi-layered design, with a first vertebral lamina, a second vertebral lamina, and a third vertebral lamina arranged from the inside out. The first vertebral lamina is a solid structure, the second vertebral lamina is a porous structure of bone-like trabeculae, and the third vertebral lamina is a smooth ice layer structure formed by a low freezing point liquid. The third vertebral lamina is in contact with autologous bone. The transmission device includes a first lifting column and a second lifting column, both of which have reverse threads on their outer surfaces. The transmission device also includes a stop device, which is sleeved on the first and second lifting columns. The stop device consists of a dovetail protrusion and a dovetail groove, and the inside of the stop device has threads of different directions that mesh with the aforementioned reverse threads. A driving device includes a retaining ring, a support rod, a support block, and a support groove. The retaining ring and the support rod are detachably connected and placed in the aforementioned annular groove. The support block has a non-penetrating support groove inside, and the support rod is inserted into the support groove and fixedly connected to the support block.

2. The interbody fusion device according to claim 1, characterized in that, The top of the shell is provided with multiple injection holes, which are positioned slightly higher than the vertebral plate, through which low freezing point liquids are injected into the shell.

3. The interbody fusion device according to claim 2, characterized in that, The low freezing point liquid is water, physiological saline, antibacterial drugs, or a mixture thereof.

4. The interbody fusion device according to claim 1, characterized in that, The first vertebral lamina is made of a cobalt-chromium-molybdenum alloy, and the second vertebral lamina is made of a titanium alloy.

5. The interbody fusion device according to claim 1, characterized in that, The retaining ring and the support rod, and the support rod and the support groove are all detachably connected by magnetic attraction.

6. A method for manufacturing an interbody fusion device according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Integrated additive manufacturing steps: Using electron beam melting or selective laser melting technology, cobalt-chromium-molybdenum alloy powder is used to integrally print a solid first vertebral plate as the inner layer structure, and titanium alloy powder is used to print a porous second vertebral plate as the outer layer structure on the outside of the first vertebral plate, so that the first vertebral plate and the second vertebral plate form a metallurgical bond at the interface. S2: Post-processing steps: Hot isostatic pressing and surface finishing are performed on the fusion device vertebral plate printed in step S1. S3: Third lamina formation step: A low freezing point liquid is injected into the accommodating cavity communicating with the second lamina, and the low freezing point liquid is solidified on the outer surface of the second lamina by conducting low temperature to form a temporary smooth ice layer of the third lamina.

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