Expandable lumbar lateral interbody fusion cage and gradient expansion mechanism thereof

Abstract

The invention relates to the clinical field of orthopedics, and discloses an expandable lumbar vertebra lateral interbody fusion cage and a gradient expansion mechanism thereof.The expandable lumbar vertebra lateral interbody fusion cage comprises a first fusion cage expansion block and a second fusion cage expansion block, the expansion mechanism is arranged on the outer side of the first fusion cage expansion block and the outer side of the second fusion cage expansion block, and the expansion mechanism comprises a first movable block and a second movable block; threaded sleeves are fixedly connected to the interiors of the first movable block and the second movable block, two-way lead screws are connected to the interiors of the two threaded sleeves in a threaded mode, and notch grooves are formed in the ends, close to the second movable block, of the two-way lead screws. The fusion cage adopts an expansion mode that two-way lead screws drive movable blocks to get close to each other and is matched with multiple limiting structures of sliding blocks and sliding grooves and wing strips and limiting strips, the stable and accurate expansion process is ensured, the intervertebral space can be effectively expanded to recover the normal height, reliable mechanical limiting is formed, pressure and twisting force generated by spine movement are resisted, and retraction of the fusion cage is prevented; the long-term stable maintenance of the expansion state is ensured.

Description

Technical Field

[0001] The present invention relates to the clinical field of orthopedics, and in particular to an expandable lumbar lateral intervertebral fusion cage and a gradient expansion mechanism thereof. Background Art

[0002] In the clinical field of orthopedics, lumbar spine disorders such as lumbar disc herniation and spondylolisthesis severely impact patients' quality of life. Lumbar lateral interbody fusion is an effective treatment for these conditions, and the performance of its core device, the lumbar lateral interbody fusion device, is crucial. Traditional lumbar lateral interbody fusion devices are mostly fixed-size structures. During surgical application, the surgeon must select the appropriate device from a variety of sizes based on the patient's actual intervertebral space size.

[0003] From a mechanical and structural perspective, the expansion function of existing fusion devices often relies on a simple wedge-shaped structure or a single screw drive. The wedge-shaped structure opens the device through tapping or external compression, but this method makes it difficult to precisely control the amplitude and direction of expansion. In the confined operating space of lumbar spine surgery, uneven expansion forces can easily cause the device to tilt or shift. Furthermore, single-screw-driven devices are prone to loosening after enduring the complex stresses of the spine. This prevents the device from maintaining a stable expansion state during postoperative recovery, thus compromising intervertebral fusion effectiveness.

[0004] Take a patient with lumbar disc herniation who underwent lumbar lateral interbody fusion surgery as an example. During the operation, the doctor implanted a traditional fixed-size fusion device for the patient, and the patient's symptoms were relieved in the early postoperative period. However, as the patient began to carry out daily activities during the recovery process, the fusion device did not match the intervertebral space well, and its expansion structure could not effectively maintain the expansion height, causing the intervertebral space to gradually narrow again, compressing the surrounding nerve tissue, and the patient reappeared symptoms such as low back pain and numbness in the lower limbs. Therefore, the present invention provides an expandable lumbar lateral intervertebral fusion device and its gradient expansion mechanism to address the shortcomings of the existing technology. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides an expandable lumbar lateral interbody fusion cage and a gradient expansion mechanism thereof, which solve the problems mentioned in the above background technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: an expandable lumbar lateral intervertebral fusion device and a gradient expansion mechanism thereof, including a fusion device expansion block 1 and a fusion device expansion block 2, the outer sides of the fusion device expansion block 1 and the fusion device expansion block 2 are provided with an expansion mechanism, the expansion mechanism includes a movable block 1 and a movable block 2, the interiors of the movable block 1 and the movable block 2 are fixedly connected with threaded sleeves, the internal threads of the two threaded sleeves are connected with bidirectional screw rods, the bidirectional screw rods are provided with a notch groove at one end near the movable block 2, and two limiting mechanisms are provided on the outer sides of the fusion device expansion block 1 and the fusion device expansion block 2.

[0007] Preferably, the outer sides of the movable block 1 and the movable block 2 are fixedly connected with two sliders, the outer sides of the sliders are fixedly connected with two wing strips, and the outer sides of the fusion device expansion block 1 and the fusion device expansion block 2 are provided with sliding grooves, and the inner sides of the sliding grooves are fixedly connected with two limit strips.

[0008] Preferably, the outer side of the slider is slidably connected to the inner side of the slide groove, and the outer side of the wing strip is slidably connected to the outer side of the limit strip.

[0009] Preferably, the limiting mechanism includes a combination block, which is fixedly connected to the top of the fusion device expansion block 1. Combination grooves are provided on both sides of the outside of the fusion device expansion block 2, and the outer side of the combination block is slidably connected to the inner side of the combination groove.

[0010] Preferably, a fixed block is fixedly connected to the inner side of the combination groove, a plurality of springs are fixedly connected to the inner side of the combination groove, one end of the plurality of springs is fixedly connected to a pressure plate, and the outer side of the pressure plate is slidably connected to the bottom of the fixed block.

[0011] Preferably, the outer side of the pressure plate is fixedly connected to a tooth plate 1, the outer side of the combination block is provided with a receiving groove, the inner side of the receiving groove is fixedly connected to a tooth plate 2, and the outer side of the tooth plate 2 is in contact with the outer side of the tooth plate 1.

[0012] Preferably, a filling hole is provided inside the first fusion device expansion block and the second fusion device expansion block, and a retaining ring is fixedly connected to the inner side of the filling hole.

[0013] Preferably, two groups of mounting holes are provided on the top of the first expansion block of the fusion device, with each group of mounting holes having two holes, and metal rods are fixedly connected to the interior of the mounting holes.

[0014] Preferably, two pushing grooves are provided on the outer side of the movable block 2.

[0015] The present invention provides an expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism. It has the following beneficial effects:

[0016] 1. The fusion device of the present invention adopts a bidirectional screw-driven expansion method in which the movable blocks approach each other, and cooperates with the multiple limiting structures of the slider and the slide groove, the wing bar and the limit bar to ensure that the expansion process is stable and accurate, and can effectively open the intervertebral space to restore the normal height. When expanded to the predetermined position, the tooth plate 1 and the tooth plate 2 in the limiting mechanism are precisely engaged to form a reliable mechanical limit to resist the pressure and torsional force generated by the movement of the spine, prevent the fusion device from retracting, ensure its long-term stable expansion state, and significantly improve the success rate and durability of the intervertebral fusion surgery.

[0017] 2. The present invention uses a special push groove to facilitate doctors to accurately control the path and depth of the fusion device into the lumbar spine, reducing the risk of surgical damage to surrounding tissues. The retaining ring on the inside of the filling hole can optimize the distribution of the filler, prevent displacement and deformation, and provide stable support for intervertebral bone fusion. The design of two sets of metal rods of different lengths facilitates the rapid and accurate determination of the position of the fusion device through postoperative imaging examinations, helping doctors to timely evaluate the postoperative status and adjust the rehabilitation plan, thereby comprehensively improving surgical safety and patient rehabilitation quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front perspective view of the present invention;

[0019] Figure 2 It is a left perspective view of the present invention;

[0020] Figure 3 It is a schematic diagram of the expansion state of the present invention;

[0021] Figure 4 It is a structural schematic diagram of the expansion mechanism of the present invention;

[0022] Figure 5 It is a structural schematic diagram of the limiting mechanism of the present invention.

[0023] Among them, 1. Fusion device expansion block 1; 2. Fusion device expansion block 2; 3. Movable block 1; 4. Movable block 2; 5. Threaded sleeve; 6. Bidirectional screw; 7. Slider; 8. Wing bar; 9. Slide; 10. Limit bar; 11. Combination block; 12. Combination slot; 13. Fixed block; 14. Spring; 15. Pressure plate; 16. Tooth plate 1; 17. Storage slot; 18. Tooth plate 2; 19. Filling hole; 20. Retaining ring; 21. Mounting hole; 22. Metal rod; 23. Push slot. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only 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 efforts are within the scope of protection of the present invention.

[0025] Please see the attached Figure 1 -Attached Figure 5An embodiment of the present invention provides an expandable lumbar lateral intervertebral fusion device and a gradient expansion mechanism thereof, comprising a fusion device expansion block 1 and a fusion device expansion block 2. Before the surgical operation, the fusion device is in an unexpanded, compact state. At this time, the fusion device expansion block 1 and the fusion device expansion block 2 are closely adjacent to each other, and the overall size is relatively small, which facilitates the doctor to accurately pass through the narrow surgical channel and deliver it to the target position of the patient's lumbar spine, thereby reducing unnecessary damage to surrounding tissues. An expansion mechanism is provided on the outside of the fusion device expansion block 1 and the fusion device expansion block 2. The expansion mechanism includes a movable block 1 3 and a movable block 2 4. The interiors of the movable blocks 1 3 and 2 4 are fixedly connected with threaded sleeves 5. The internal threads of the two threaded sleeves 5 are connected with bidirectional screws 6. The bidirectional screws 6 have a notch groove near one end of the movable block 2 4. When the fusion device reaches the predetermined position, a surgical instrument is used to penetrate the notch groove of the bidirectional screw 6 near one end of the movable block 2 4 to apply a rotational force to the bidirectional screw 6. Due to the special thread design of the bidirectional screw 6, its positive and negative trapezoidal structure makes it possible for the two threaded sleeves 5 threadedly connected thereto to move in opposite directions when rotating. The threaded sleeve 5 serves as the core driving component of the movable block 1 3 and the movable block 2 4, driving the movable block 1 3 and the movable block 2 4 to approach each other. During the movement of the movable block 1 3 and the movable block 2 4, the slider 7 fixedly connected to the outside thereof slides along the chute 9 opened on both sides of the outside of the fusion device expansion block 1 and the fusion device expansion block 2 2. At the same time, the wing bar 8 fixedly connected to the outside of the slider 7 also slides along the limit bar 10 fixedly connected to the inside of the chute 9. This design not only provides precise guidance for the movement of the movable block 1 3 and the movable block 2 4, preventing them from offsetting or shaking during movement, but also enhances the stability of the entire expansion process. As the movable block 1 3 and the movable block 2 4 continue to approach, they will gradually squeeze the inner wall of the chute 9 of the fusion device expansion block 1 and the fusion device expansion block 2 2. Because the slideway 9 is integrally structured with the fusion device expansion block 1 and the fusion device expansion block 2, when subjected to compressive force, the fusion device expansion block 1 and the fusion device expansion block 2 gradually separate, thereby expanding the fusion device, widening the intervertebral space, restoring the normal intervertebral height, and creating favorable spatial conditions for subsequent intervertebral fusion. Two limiting mechanisms are provided on the exterior of the fusion device expansion block 1 and the fusion device expansion block 2. The limiting mechanisms include a combination block 11, which is fixedly connected to the top of the fusion device expansion block 1. Combination slots 12 are defined on both sides of the exterior of the fusion device expansion block 2. During the fusion device expansion process, the combination block 11, which is fixedly connected to the top of the fusion device expansion block 1, slides along the combination slots 12 defined on both sides of the exterior of the fusion device expansion block 2 as the fusion device expansion block 1 and the fusion device expansion block 2 gradually separate. The spring 14 fixedly connected to the interior of the combination slot 12 is initially in a neutral position. When the combination block 11 begins to slide, the spring 14 is squeezed and gradually compressed, simultaneously pushing the pressure plate 15 toward the combination block 11.Tooth plate 16 fixedly connected to the outside of the pressure plate 15 also moves accordingly, and interacts with tooth plate 2 18 fixedly connected to the receiving groove 17 provided on the outside of the combination block 11. As the fusion device continues to expand, tooth plate 16 and tooth plate 2 18 are constantly offset from each other. When the fusion device expands to a suitable position, that is, when the distance between the fusion device expansion block 1 and the fusion device expansion block 2 2 reaches the expected distance and no longer changes, tooth plate 2 18 will have a limiting effect on tooth plate 16. At this time, tooth plate 16 and tooth plate 2 18 engage with each other to prevent the fusion device from retracting due to factors such as internal pressure, ensuring that the fusion device can continue to stably maintain its expanded state after surgery, thereby ensuring the effectiveness of the surgery. The outer side of the combination block 11 is slidably connected to the inner side of the combination groove 12, and the inner side of the combination groove 12 is fixedly connected to a fixed block 13. The inner side of the combination groove 12 is fixedly connected to multiple springs 14, and one end of the multiple springs 14 is fixedly connected to a pressure plate 15. The outer side of the pressure plate 15 is slidably connected to the bottom of the fixed block 13, and the outer side of the pressure plate 15 is fixedly connected to a tooth plate 16. A receiving groove 17 is provided on the outer side of the combination block 11, and a tooth plate 2 18 is fixedly connected to the inner side of the receiving groove 17. The outer side of the tooth plate 2 18 is fitted with the outer side of the tooth plate 16. The outer sides of the movable block 1 3 and the movable block 2 4 are fixedly connected to two sliders 7, and the outer side of the slider 7 is fixedly connected to two wing bars 8. The outer sides of the fusion device expansion block 1 and the fusion device expansion block 2 are provided with slide grooves 9. The inner side of the slide groove 9 is fixedly connected to two limit bars 10. The outer side of the slider 7 is slidably connected to the inner side of the slide groove 9, and the outer side of the wing bar 8 is slidably connected to the outer side of the limit bar 10. Both the fusion device expansion block 1 and the fusion device expansion block 2 are internally provided with a filling hole 19, designed to provide a passage for the implantation of fillers such as bone graft materials during fusion surgery. A retaining ring 20 is fixedly connected to the inside of the filling hole 19 to provide additional support for the filler during and after the implantation process. On the one hand, the retaining ring 20 prevents the filler from moving too deep into the fusion device during implantation, ensuring that the filler is evenly distributed in the appropriate position. On the other hand, during postoperative recovery, when the patient engages in daily activities and the spine is subjected to various pressures, the retaining ring 20 can share some of the pressure from the filler, preventing the filler from shifting or deforming due to excessive pressure, thereby improving the stability of the filler during fusion surgery and promoting smooth intervertebral bone fusion. A retaining ring 20 is fixedly connected to the inside of the filling hole 19. The top of the fusion device expansion block 1 is provided with two sets of mounting holes 21, each set of two mounting holes 21. Two sets of mounting holes 21 are located on the top of the fusion cage expansion block 1. Each set contains two mounting holes 21, and the metal rods 22 fixed therein are of different lengths. This unique design is of great significance. During postoperative patient examinations, such as imaging studies (such as X-rays and CT scans), the different lengths of the metal rods 22 will appear in different shapes and positions, allowing doctors to clearly distinguish the anterior-posterior position of the fusion cage in the patient's lumbar spine.This provides an important reference for evaluating the postoperative status of the fusion device and determining whether it has shifted, etc., which helps doctors to grasp the patient's recovery status in a timely and accurate manner, and provides reliable information support for subsequent treatment adjustments. A metal rod 22 is fixedly connected to the inside of the mounting hole 21, and two push grooves 23 are provided on the outside of the movable block 24. The two push grooves 23 provided on the outside of the movable block 24 are key structures for doctors to accurately deliver the fusion device during the surgical operation. During the operation, the doctor uses professional surgical clamping tools, such as special pliers, to accurately clamp the positions of the two push grooves 23. This design allows the doctor to control the position and direction of the fusion device more stably and accurately, and smoothly pass the fusion device through a complex surgical path and deliver it to the patient's lumbar target area. Compared with the traditional method of delivering the fusion device, operating through the push groove 23 greatly improves the accuracy and controllability of the operation, reduces unnecessary interference and damage risks to surrounding tissues during the operation, and provides a strong guarantee for the successful implementation of the operation.

[0026] Specifically, first, the doctor uses a special medical clamping tool to accurately clamp the two push grooves 23 on the outside of the movable block 2 4. The special design of the push groove 23 can provide a stable fulcrum, ensuring that when the fusion device is delivered to the patient's lumbar spine, the doctor can use the tool to accurately control the direction and depth of the fusion device, reduce unnecessary contact with the nerves, blood vessels and muscle tissues around the lumbar spine, and reduce the risk of surgical injury. When the fusion device is safely delivered to the predetermined position of the diseased intervertebral space of the lumbar spine, it enters the critical expansion operation stage. Subsequently, the doctor uses an adapted surgical instrument to insert the bidirectional screw 6 into the notched groove near one end of the movable block 2 4, and by rotating the bidirectional screw 6, the two threaded sleeves 5 threadedly connected thereto are driven to move in opposite directions respectively by virtue of its unique design of positive and negative trapezoidal threads. The threaded sleeve 5, as the core transmission component, is firmly connected to the movable block 1 3 and the movable block 2 4, thereby bringing the movable block 1 3 and the movable block 2 4 close to each other. During this process, the sliders 7 on the outside of the movable blocks 13 and 24 slide along the chute 9 on the outside of the fusion device expansion block 1 and the fusion device expansion block 2, and the wing bars 8 on the outside of the sliders 7 slide synchronously along the limit bars 10 on the inside of the chute 9. This multiple limiting structure design can effectively prevent the movable blocks from offsetting or shaking during movement, ensuring that the expansion process of the fusion device is stable and accurate. As the movable blocks 13 and 24 continue to approach, they apply a squeezing force to the inner wall of the chute 9 of the fusion device expansion block 1 and the fusion device expansion block 2. Since the chute 9 and the fusion device expansion block are integrally formed, the force causes the fusion device expansion block 1 and the fusion device expansion block 2 to gradually separate, thereby achieving the expansion and expansion of the fusion device. This operation can effectively open the intervertebral space that has been narrowed due to lesions and restore the normal height of the intervertebral space. It not only provides sufficient space for the subsequent implantation of bone graft materials, but also reduces the pressure of the intervertebral disc on the peripheral nerves and relieves the patient's pain symptoms. During the expansion process of the fusion device, the limiting mechanism plays an important role. As the expansion blocks separate, the assembly block 11 at the top of the fusion device expansion block 1 slides along the assembly groove 12 on the outside of the fusion device expansion block 2. The spring 14 on the inside of the assembly groove 12 is gradually compressed, pushing the pressure plate 15 and the tooth plate 16 connected to it to move, so that the tooth plate 16 and the tooth plate 2 18 in the receiving groove 17 on the outside of the assembly block 11 are constantly offset. When the fusion device expands to the ideal position, that is, when the distance between the fusion device expansion block 1 and the fusion device expansion block 2 reaches the predetermined value, the tooth plate 2 18 precisely engages with the tooth plate 16 to form a reliable mechanical limiting structure. This limiting effect can withstand the pressure and torsional force that the spine is subjected to during the patient's daily activities, prevent the fusion device from retracting, ensure that it maintains its expanded state for a long time, and guarantee the therapeutic effect of the intervertebral fusion surgery. In addition, the filling holes 19 inside the fusion device expansion block 1 and the fusion device expansion block 2 are used to implant bone graft materials or other substances that promote intervertebral fusion.The retaining ring 20 fixed inside the filling hole 19 prevents the filler from excessively moving deep into the fusion cage during the filling process, ensuring that the filler is evenly distributed in the intervertebral space and fully promoting bone fusion. After surgery, when the patient engages in physical activity and the spine is under pressure, the retaining ring 20 can share the pressure on the filler, preventing the filler from shifting or deforming, providing a stable support environment for intervertebral bone fusion and improving the success rate of fusion. The two sets of mounting holes 21 at the top of the fusion cage expansion block 1 each contain two holes with metal rods 22 of different lengths fixed inside. This design has important clinical significance. When the patient undergoes postoperative imaging examinations such as X-rays and CT scans, the metal rods 22 of different lengths will show unique morphological and positional characteristics in the images, allowing doctors to quickly and accurately distinguish the anterior and posterior position of the fusion cage in the patient's lumbar spine. This helps doctors promptly assess the postoperative status of the fusion cage and determine whether it has abnormal conditions such as displacement or tilt, thereby providing a reliable basis for formulating and adjusting the patient's subsequent rehabilitation treatment plan, ensuring that the patient receives accurate and effective treatment.

[0027] Working principle: First, the doctor will use professional tools to clamp the positions of the two pushing grooves 23 and send the fusion device into the patient's lumbar vertebra, and then rotate the bidirectional screw rod 6 through the notch groove position of the bidirectional screw rod 6, so that the two threaded sleeves 5 respectively bring the movable block 1 3 and the movable block 2 4 closer to each other, which will squeeze the sliding grooves 9 of the fusion device expansion block 1 and the fusion device expansion block 2 2, so that the fusion device expansion block 1 and the fusion device expansion block 2 2 are gradually separated, so that the expansion operation can be completed, and the tooth plate 1 16 and the tooth plate 2 18 will continue to stagger their positions until the distance between the fusion device expansion block 1 and the fusion device expansion block 2 2 remains unchanged, so that the tooth plate 2 18 will limit the tooth plate 16 to prevent the expansion operation from retracting in the future; in addition, arranging a retaining ring 20 inside the filling hole 19 can increase the support effect of the filler, and the metal rods 22 inside the two sets of mounting holes 21 have different lengths, which is convenient for distinguishing the front and rear positions of the fusion device during future inspections.

[0028] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An expandable lumbar lateral intervertebral fusion cage and its gradient expansion mechanism, comprising a fusion cage expansion block 1 (1) and a fusion cage expansion block 2 (2), characterized in that: An expansion mechanism is provided on the outside of the fusion device expansion block 1 (1) and the fusion device expansion block 2 (2), and the expansion mechanism includes a movable block 1 (3) and a movable block 2 (4). The insides of the movable block 1 (3) and the movable block 2 (4) are fixedly connected with a threaded sleeve (5), and the internal threads of the two threaded sleeves (5) are connected with a bidirectional screw rod (6). A notch groove is provided at one end of the bidirectional screw rod (6) close to the movable block 2 (4). Two limiting mechanisms are provided on the outside of the fusion device expansion block 1 (1) and the fusion device expansion block 2 (2).

2. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 1, characterized in that: The outer sides of the movable block 1 (3) and the movable block 2 (4) are fixedly connected to two sliders (7), and the outer sides of the sliders (7) are fixedly connected to two wing strips (8). The outer sides of the fusion device expansion block 1 (1) and the fusion device expansion block 2 (2) are both provided with sliding grooves (9), and the inner sides of the sliding grooves (9) are fixedly connected to two limit strips (10).

3. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 2, characterized in that: The outer side of the slider (7) is slidably connected to the inner side of the slide groove (9), and the outer side of the wing strip (8) is slidably connected to the outer side of the limit strip (10).

4. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 1, characterized in that: The limiting mechanism comprises a combination block (11), the combination block (11) is fixedly connected to the top of the fusion device expansion block (1), and combination grooves (12) are provided on both sides of the outside of the fusion device expansion block (2), and the outer side of the combination block (11) is slidably connected to the inner side of the combination groove (12).

5. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 4, characterized in that: The inner side of the combined groove (12) is fixedly connected to a fixed block (13), the inner side of the combined groove (12) is fixedly connected to a plurality of springs (14), one end of the plurality of springs (14) is fixedly connected to a pressure plate (15), and the outer side of the pressure plate (15) is slidably connected to the bottom of the fixed block (13).

6. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 5, characterized in that: The outer side of the pressure plate (15) is fixedly connected to a tooth plate 1 (16), the outer side of the combination block (11) is provided with a receiving groove (17), the inner side of the receiving groove (17) is fixedly connected to a tooth plate 2 (18), and the outer side of the tooth plate 2 (18) is in contact with the outer side of the tooth plate 1 (16).

7. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 1, characterized in that: A filling hole (19) is provided inside each of the fusion device expansion block 1 (1) and the fusion device expansion block 2 (2), and a retaining ring (20) is fixedly connected to the inner side of the filling hole (19).

8. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 1, characterized in that: Two groups of mounting holes (21) are provided on the top of the fusion device expansion block (1), and each group of mounting holes (21) has two mounting holes. Metal rods (22) are fixedly connected to the interior of the mounting holes (21).

9. The expandable lumbar lateral interbody fusion cage and its gradient expansion mechanism according to claim 1, characterized in that: Two pushing grooves (23) are provided on the outer side of the movable block 2 (4).

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