Interbody fusion cage and preparation method thereof

Abstract

The invention provides an interbody fusion cage which comprises a shell and vertebral plates, the shell is not lower than the vertebral plates, a containing cavity is formed between the shell and the vertebral plates, the vertebral plates are symmetrically arranged up and down, each vertebral plate is provided with a first sliding rail and a second sliding rail and is further provided with a vertical groove and a circular ring groove, the vertebral plates are of a multi-layer design, and the vertical grooves and the circular ring grooves are formed in the shell. A first vertebral plate and a second vertebral plate are respectively arranged from inside to outside; the transmission device comprises a first lifting column and a second lifting column, reverse threads are arranged on the outer surfaces of the first lifting column and the second lifting column, the transmission device further comprises a stopping device, the first lifting column and the second lifting column are sleeved with the stopping device, and the stopping device is composed of a dovetail protruding block and a dovetail groove; the driving device comprises a clamping ring, a supporting rod, a supporting block and a supporting groove, the clamping ring and the supporting rod are detachably connected and placed in the annular groove, and the supporting rod is inserted into the supporting groove and fixedly connected with the supporting block. According to the technical scheme, the damage of the prosthesis surface to the autogenous bone in the operation can be effectively avoided.

Description

Technical Field

[0001] The present invention relates to the field of orthopedic implants, and in particular to an intervertebral fusion cage. Background Art

[0002] Spinal fusion is the gold standard surgical procedure for treating degenerative disc disease, spondylolisthesis, instability, and certain types of fractures. The core goal of this procedure is to restore the normal height of the intervertebral space at the affected level, reestablish the physiological curvature and stability of the spine, and provide a supportive environment for eventual bony fusion through the implantation of an intervertebral fusion cage (cage). A successful fusion procedure is highly dependent on achieving long-term, stable, and robust osseointegration between the cage and the host bone.

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

[0004] However, this porous structure, designed to optimize long-term bioperformance, presents significant and unexpected challenges during surgical implantation. The inherently high surface roughness and high coefficient of friction associated with the porous structure create significant shear and scraping forces on the crucial cartilaginous endplates on the upper and lower vertebral surfaces during implantation through a narrow surgical channel. The cartilaginous endplate is a thin, tough layer of cartilage covering the vertebral cancellous bone. It acts as a barrier, protecting the underlying bone from damage while also fulfilling the critical function of nutrient exchange between the intervertebral discs. Iatrogenic endplate injury has become one of the most prominent complications associated with porous fusion device implantation. This injury triggers a series of cascading clinical challenges: increased surgical risk: scratching the endplate exposes the underlying, richly vascularized cancellous bone, leading to unnecessary bleeding, disrupting the surgical field, and prolonging operative time. Basis for fusion failure: Damaged endplates lose their load-bearing barrier function. Under the continued axial stress of surgery, the fusion cage is more likely to sink into the vertebral body, a phenomenon known as subsidence. Subsidence can lead to loss of intervertebral disc height, alterations in spinal curvature, and even nerve root compression, ultimately causing surgical failure. Impact on long-term outcomes: Endplate damage can further impact the metabolic environment of the intervertebral disc. Although the fused segment itself is no longer active, the risk of degeneration in adjacent segments may increase.

[0005] Currently, surgeons often rely on empirical, forceful percussion to address implant resistance. This not only places extremely high demands on the surgeon's feel and control, but also makes the surgical process fraught with uncertainty: insufficient percussion force may result in poor placement of the fusion device; excessive force or directional deviation directly exacerbates endplate damage. Some compromises exist in the industry, such as spraying smooth coatings such as hydroxyapatite (HA) or titanium nitride on key contact areas of porous fusion devices, or designing streamlined shapes. However, these methods are essentially compromises: the presence of the coating may wear or degrade in the long term, hindering bone ingrowth; and optimizing the shape has little effect on drag reduction for 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 the present invention is to provide an intervertebral fusion cage and a preparation method thereof, so as to solve the technical problem of iatrogenic endplate damage caused to the human body during the implantation of the intervertebral fusion cage.

[0007] In order to solve the above problems, the present invention provides an intervertebral fusion device and a preparation method thereof, specifically comprising: a shell, a vertebral plate, the height of the shell is not lower than the height of the vertebral plate, a accommodating chamber is formed between the shell and the vertebral plate, the vertebral plate is symmetrically arranged up and down, a first slide rail and a second slide rail are provided on the vertebral plate, and a vertical groove and an annular groove are also provided. The vertebral plate is a multi-layer design, and a first vertebral plate and a second vertebral plate are respectively provided from the inside to the outside; a transmission device, the transmission device comprises a first lifting column and a second lifting column, the outer surfaces of both of which are provided with reverse threads, the transmission device also comprises a stopping device, the stopping device is sleeved on the aforementioned first lifting column and the second lifting column, the stopping device consists of a dovetail protrusion and a dovetail groove, and the internal arrangement of the stopping device has different threads that engage with the aforementioned reverse threads; a driving device, the driving device comprises a clamping ring, a support rod, a support block, and a support groove, the clamping ring is detachably connected to the support rod and placed in the annular groove, a non-penetrating support groove is provided inside the support block, and the support rod is inserted into the support groove and fixedly connected to the support block.

[0008] Furthermore, a plurality of injection holes are respectively provided on the top and bottom of the shell. The injection holes are slightly higher than the vertebral plates, and low-freezing-point liquid is injected into the shell through the injection holes.

[0009] Furthermore, the low freezing point liquid is water, physiological saline, antibacterial drugs or a mixture thereof.

[0010] Furthermore, the first vertebral plate is a solid structure, and the second vertebral plate is a porous structure similar to trabecular bone.

[0011] Furthermore, the intervertebral fusion cage further comprises a third vertebral plate, which is a smooth ice layer structure formed by a low-freezing-point liquid, wherein the third vertebral plate is in contact with the autologous bone.

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

[0013] Furthermore, the clamping ring and the support rod, and the support rod and the support groove are all detachably connected by magnetic attraction.

[0014] The present invention also provides a preparation 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, using cobalt-chromium-molybdenum alloy powder to integrally print to form a solid first vertebral plate as an inner layer structure, and using titanium alloy powder to print outside the first vertebral plate to form a second vertebral plate with a porous structure as an outer layer structure, so that the first vertebral plate and the second vertebral plate form a metallurgical bond at the interface; S2: post-processing step: performing hot isostatic pressing and surface finishing on the fusion device vertebral plate printed in step S1; S3: third vertebral plate forming step: injecting a low-freezing point liquid into the accommodating chamber connected to the second vertebral plate, and solidifying the low-freezing point liquid on the outer surface of the second vertebral plate by conducting low temperature to form a temporary third vertebral plate smooth ice layer.

[0015] According to the technical solution of the present invention, since the height of the shell is not lower than the height of the vertebral plate, a accommodating chamber is formed between the shell and the vertebral plate, and the vertebral plate is located in the middle of the shell. The vertebral plates are symmetrically arranged up and down, and the vertebral plates are provided with a first slide rail and a second slide rail for placing two transmission devices diagonally. A vertical groove and an annular groove are also provided, so that the transmission device can push the upper and lower vertebral plates to move vertically and adjust the transmission device to move in the horizontal direction. The vertebral plate is a multi-layer design, and the first vertebral plate and the second vertebral plate are respectively provided from the inside to the outside; the transmission device includes a first lifting column and a second lifting column. The outer surface is provided with a reverse thread, and the transmission device also includes a stop device, which is mounted on the first and second lifting columns. During the rotation of the stop device, the first and second lifting columns move vertically. The stop device is composed of a dovetail protrusion and a dovetail groove. The internal threads of the stop device are arranged in different directions and mesh with the reverse thread. The driving device includes a clasp, a support rod, a support block, and a support groove. The clasp is detachably connected to the support rod and placed in the annular groove. The support block is provided with a non-through support groove. The support rod is inserted into the support groove and fixedly connected to the support block. Through the above arrangement, the clasp is rotated, the clasp drives the support rod to rotate, and the support rod drives the stop device to rotate, thereby driving the first and second lifting columns to move up and down, so that the upper and lower vertebral plates approach the outer surface of the shell, 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 withdrawn, and then the two opposing support rods are moved to move the transmission device so that the dovetail protrusions and dovetail grooves on both sides are connected. Finally, the clasp is replaced to complete the fixation. Therefore, the technical solution of the present invention can effectively prevent the technical problem of iatrogenic endplate damage to the human body during intervertebral fusion cage implantation, and fundamentally resolve the inherent contradiction between "instantaneous low friction during implantation" and "long-term high bone integration." BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 An external view of the intervertebral fusion cage is shown; Figure 2 An exploded view of the internal structure of the intervertebral fusion cage is shown; Figure 3 A top view of the lamina is shown; Figure 4 shows a cross-sectional view of the transmission; Figure 5 shows a cross-sectional view of the drive unit; Figure 6 A cross-sectional view of the lamina is shown; Among them, the above-mentioned drawings include the following figure marks: 10, shell; 101, injection hole; 102, accommodating chamber; 20, vertebral plate; 201, first vertebral plate; 202, second vertebral plate; 203, third vertebral plate; 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, stopping device; 3031, dovetail protrusion; 3032, dovetail groove; 304, reverse thread; 40, driving device; 401, retaining ring; 402, support rod; 403, support block; 4031, support groove. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0019] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary, rather than as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0020] like Figure 1 As shown: An intervertebral fusion device includes: a shell 10, with multiple injection holes 101 penetrating the upper and lower parts of the shell, a vertebral plate 20, the position of the vertebral plate is slightly lower than the position of the shell, so that an accommodating chamber 102 is formed between the two, and the position of the injection hole 101 is slightly higher than the position of the vertebral plate 20.

[0021] like Figures 2-5 As shown in the figure: the vertebral plate 20 of the intervertebral fusion cage is provided with a first slide rail 204 and a second slide rail 205, and is also provided with a vertical groove 206 and an annular groove 207. The vertebral plate 20 is a multi-layer design, and is respectively provided with a first vertebral plate 201 and a second vertebral plate 202 from the inside to the outside; the transmission device 30 includes a first lifting column 301 and a second lifting column 302, both of which are provided with reverse threads 304 on their outer surfaces. The transmission device also includes a stopper 303, which is sleeved on the first lifting column. The lowering column 301 and the second lifting column 302 have a stopper mechanism consisting of a dovetail protrusion 3031 and a dovetail groove 3032. The drive mechanism 40 includes a snap ring 401, a support rod 402, a support block 403, and a support groove 4031. The snap ring 401 is detachably connected to the support rod 402 and positioned within the annular groove 207. The support block has a non-through support groove 4031, into which the support rod 402 is inserted and fixedly connected to the support block 403. The snap ring 401 and support rod 402, and the support rod 402 and support groove 4031, are both detachably connected via magnetic attraction.

[0022] When in use, first place the transmission device 30 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 at diagonal corners of 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 clamping ring by magnetic attraction. Then, the clamping 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 is provided with threads in opposite directions, which engage with the reverse threads on the outer surfaces of the first lifting column and the second lifting column, the first lifting column and the second lifting column will extend in the vertical direction, and the first vertebral plate and the second vertebral plate will also extend in the vertical direction. After reaching the preset position, the adjacent support rods of the two stop devices are removed, and the opposite support rods are retained. Then, the support rods are moved through the vertical groove to make the two transmission devices approach the middle of the intervertebral fusion device until the dovetail protrusions and dovetail grooves of the two stop devices coincide. This approach yields the following beneficial effects: Because the porous structure of the second vertebral plate is slightly lower than the shell surface and is adjustable, it eliminates the risk of damage to human bone during implantation. During the critical implantation phase, its outer surface achieves a temporary, extremely smooth, low-friction state, ensuring zero-damage implantation into the ideal position. Once implanted, it quickly and reliably transforms back to its original biofriendly porous surface, seamlessly transitioning to efficiently promote bone ingrowth. This solution will perfectly resolve a core contradiction in current clinical practice and possesses significant clinical significance and market value.

[0023] like Figure 6 As shown, the vertebral plate includes a three-layer structure. The innermost layer is a first vertebral plate 201 formed of a solid structure made of cobalt-chromium-molybdenum alloy. The middle layer is a second vertebral plate 202 formed of a porous structure similar to trabeculae made of titanium alloy. The third layer is a smooth ice layer structure formed by a low-freezing-point liquid, namely the third vertebral plate 203. Among them, the third vertebral plate is in contact with the human bone. Through this design, on the one hand, since the third vertebral plate is a smooth ice surface, the instantaneous low friction of the implant can be reduced. On the other hand, since the second vertebral plate is a porous structure similar to trabeculae, the long-term bone integration ability can be effectively improved.

[0024] In order to better form a complete third lamina, the low freezing point liquid can be the following: Sterile water: The purest choice, with a freezing point of 0°C. Normal saline, which has the same osmotic pressure as human body fluids, is the safest and most standard choice, avoiding osmotic shock to cells. Balanced Salt Solution (BSS): Such as Dulbecco's Phosphate Buffered Saline (DPBS) and Ringer's Solution. It not only provides osmotic pressure, but also contains ions such as glucose, calcium, potassium, and magnesium, which can better maintain cell activity and reduce potential effects on surrounding tissues. It is superior to ordinary normal saline. Lactated Ringer's solution: Closer to the electrolyte composition of plasma, and contains sodium lactate as a buffer, with a more stable pH value.

[0025] Specific functional substances are added to the above solution to form a complex solution, allowing the third vertebral lamina (ice layer) to exert its therapeutic effects both before and after thawing. Antibacterial / anti-infective drugs: Antibiotics such as vancomycin, tobramycin, and gentamicin are slowly released directly at the surgical site to prevent postoperative infection. Antimicrobial peptides: A new type of antimicrobial agent that is less likely to develop drug resistance. Osteogenic / osteoinductive drugs: BMPs (bone morphogenetic proteins), such as BMP-2 and BMP-7, are currently the most potent osteoinductive growth factors, significantly accelerating and enhancing osseointegration between the vertebral body and the fusion cage. Osteogenic peptides: Small molecules that stimulate bone formation. Antiresorptive drugs such as denosumab can be used to inhibit osteoclast activity and are particularly suitable for patients with osteoporosis. Analgesic / anti-inflammatory drugs: Local anesthetics such as bupivacaine are slowly released after the ice layer melts, providing significant analgesia for 48-72 hours after surgery and reducing opioid use. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ketorolac, reduce postoperative inflammation and pain. Steroids, such as dexamethasone, are potent anti-inflammatory drugs but should be used with caution to avoid affecting bone healing. Imaging contrast agents, such as gadopentetate dimeglumine (for MRI) or iohexol (for CT), enhance the visibility of the ice layer around the fusion cage on imaging, allowing the surgeon to confirm the integrity, smoothness, and uniformity of the ice layer during surgery using real-time fluoroscopy, and to monitor the ice layer's melting process postoperatively.

[0026] The present invention also includes a method for preparing the lamina, which is specifically as follows: the first lamina 201 and the second lamina 202 are prepared by the following steps: S1: 3D Model Design and Printing: Using computer-aided design (CAD) software, a solid 3D model of the first lamina 201 and a porous 3D model of the second lamina 202 are constructed based on the anatomical parameters of the target vertebra. The porous model of the second lamina 202 requires preset parameters for porosity, pore size, and wire diameter to simulate the structure of natural trabecular bone. The final, integrated digital model is then imported into an electron beam melting (EBM) or selective laser melting (SLM) metal 3D printer.

[0027] S2: Substrate preparation and printing: The first vertebral plate 201 uses medical-grade cobalt-chromium-molybdenum (CoCrMo) alloy powder as the printing material. This material has high strength and wear resistance and is suitable for load-bearing core structures. The second vertebral plate 202 uses medical-grade titanium alloy Ti6Al4V ELI powder. Its excellent biocompatibility and elastic modulus are more conducive to bone ingrowth. Under an inert gas protection environment, the metal powder is melted layer by layer by high-energy electron beam or laser, and integrated printing is performed, so that the first vertebral plate (1) and the second vertebral plate (2) are metallurgically bonded at the interface to form a solid integral structure.

[0028] S3: Post-Processing: After printing is complete, support structures are removed, and the printed part undergoes Hot Isostatic Pressing (HIP) to eliminate internal residual stress and close microscopic pores that may have been created during the printing process, significantly improving its mechanical properties and fatigue life. Finally, surface finishing treatments such as sandblasting and electrolytic polishing are performed to remove attached powder and burrs to obtain the final product.

[0029] 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: S4: Preoperative Cleaning and Pretreatment: Before surgery, the fusion device body (i.e., the shell structure containing the first and second vertebral lamina) is placed in a low-temperature environment (approximately 4°C) to cool. A sterile, low-freezing-point liquid, such as saline or a solution containing an antimicrobial agent, is injected into the accommodating chamber 102 through the injection port 101 provided in the shell 10 to fully infiltrate the porous structure of the second vertebral lamina 202 and ensure that no bubbles remain in the chamber.

[0030] S5: Intraoperative Instant Freeze Forming: Prior to implantation, a specialized operating tool, pre-chilled to ultra-low temperatures (e.g., -196°C liquid nitrogen or -78°C dry ice), is placed in contact with the fusion device's drive mechanism 40 or retaining mechanism 303 to transfer cold air. This cold air is rapidly transferred to the entire outer surface of the fusion device through the highly thermally conductive metal first and second laminas 201, 202. This causes the liquid infiltrating the porous outer layer of the second lamina 202 and within the accommodating chamber 102 to instantly solidify, forming a smooth, solid layer of ice on the outer surface of the second lamina 202, which becomes the third lamina 203.

[0031] S6: Postoperative Thawing and Functional Transformation: Once the fusion cage is precisely implanted in the ideal position in the intervertebral space, heat from the surrounding tissue (approximately 37°C) is continuously transferred to the 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 seeps out through the injection hole 101, where it is metabolized normally by the body. At this point, the inherent porous structure of the second lamina 202 is fully exposed, directly contacting the vertebral endplates and immediately beginning to exert its biological function of promoting bone ingrowth.

[0032] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0033] For ease of description, spatially relative terms such as "above," "on the upper surface of," "on top of," etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that 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 the device in the figures is inverted, a device described as "above" or "on top of" other devices or structures would then be positioned as "below" or "below" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0034] In addition, it should be noted that the use of "first", "second", and the like words to qualify parts is merely for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0035] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art based on the spirit and principles of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An intervertebral fusion cage, characterized in that: include: A shell and a vertebral plate, wherein the height of the shell is not lower than the height of the vertebral plate, and a accommodating chamber is formed between the shell and the vertebral plate. The vertebral plate is symmetrically arranged up and down, and is provided with a first slide rail and a second slide rail, and is also provided with a vertical groove and an annular groove. The vertebral plate is a multi-layer design, and is provided with a first vertebral plate and a second vertebral plate from the inside to the outside respectively; A transmission device, the transmission device comprising a first lifting column and a second lifting column, both of which have oppositely directed threads on their outer surfaces, the transmission device further comprising a stopper, the stopper being sleeved on the first and second lifting columns, the stopper comprising a dovetail protrusion and a dovetail groove, the stopper internally provided with threads in different directions engaging with the oppositely directed threads; The driving device includes a retaining ring, a support rod, a support block, and a support groove. The retaining ring is detachably connected to the support rod and is placed in the aforementioned annular groove. A non-through support groove is provided inside the support block. The support rod is inserted into the support groove and fixedly connected to the support block.

2. The intervertebral fusion cage according to claim 1, characterized in that: The top and bottom of the shell are respectively provided with a plurality of injection holes, and the injection holes are arranged slightly higher than the vertebral plate, and low-freezing-point liquid is injected into the shell through the injection holes.

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

4. The intervertebral fusion cage according to claim 1, characterized in that: The first vertebral plate is a solid structure, and the second vertebral plate is a porous structure similar to trabecular bone.

5. The intervertebral fusion cage according to claim 4, characterized in that: The intervertebral fusion cage further includes a third vertebral plate having a smooth ice layer structure formed by a liquid with a low freezing point, wherein the third vertebral plate is in contact with the autologous bone.

6. The intervertebral fusion cage according to claim 1, characterized in that: The first vertebral plate is made of a cobalt-chromium-molybdenum alloy, and the second vertebral plate is made of a titanium alloy.

7. The intervertebral fusion cage according to claim 1, characterized in that: The clamping ring and the supporting rod, and the supporting rod and the supporting groove are all detachably connected by magnetic attraction.

8. A method for manufacturing an intervertebral fusion cage according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Integrated additive manufacturing step: Using electron beam melting or selective laser melting technology, cobalt-chromium-molybdenum alloy powder is used to integrally print to form a solid first lamina as an inner layer structure, and titanium alloy powder is used to print outside the first lamina to form a second lamina with a porous structure as an outer layer structure, so that the first lamina and the second lamina form a metallurgical bond at the interface; S2: Post-processing step: hot isostatic pressing and surface finishing of the fusion cage vertebral plate printed in step S1; S3: Third vertebral plate forming step: injecting a low-freezing point liquid into the accommodating chamber connected to the second vertebral plate, and solidifying the low-freezing point liquid on the outer surface of the second vertebral plate by conducting low temperature to form a temporary third vertebral plate smooth ice layer.

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