intervertebral fusion cage

Abstract

The present invention relates to an intervertebral fusion device, which includes a shaft body, a first distraction member and a fusion body. The first distraction member is mounted on the shaft body and can move axially along the shaft body. The first distraction member has an inner end and an outer end distributed radially along the shaft body, and the inner end is connected to the shaft body. The fusion body is circumferentially arranged around the shaft body and connected to the outer end of the first distraction member. A first slide is provided on the inner wall of the fusion body. An angle is provided between the extension direction of the first slide and the outer wall of the fusion body. The outer end of the first distraction member is movably arranged in the first slide. In the above-mentioned intervertebral fusion device, the first distraction member can change the distance between the fusion body and the shaft body by sliding along the first slide, thereby changing the size of the distraction of the intervertebral fusion device. When the intervertebral fusion device is implanted, the distraction range of the intervertebral fusion device can be adjusted according to the specific conditions of the intervertebral space, and the contact surface with the vertebral space can be increased to better match the intervertebral space, maintain the height of the intervertebral space, and restore the physiological curvature of the lumbar spine.

Description

Technical Field

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

[0002] Lumbar degenerative disease (including lumbar spinal stenosis, spondylolisthesis, degenerative scoliosis, and disc-related diseases) and structural damage are a major cause of lower back and leg pain, as well as impaired sensory and motor function, and even loss. Treatment focuses on relieving nerve compression and restoring spinal stability. Intervertebral fusion devices implanted within the affected intervertebral space to expand, compress, and stabilize the affected intervertebral space have become a standard treatment for lumbar degenerative disease.

[0003] Due to the special physiological structure of the lumbar intervertebral space, it is difficult for conventional intervertebral fusion devices to simultaneously meet the two requirements of restoring the intervertebral space height and increasing the contact surface between the fusion device and the upper and lower end plates after implantation, which affects the postoperative treatment effect. Summary of the Invention

[0004] Based on this, it is necessary to provide an intervertebral fusion device that has a high degree of matching with the lumbar intervertebral space and achieves a good intervertebral fusion effect.

[0005] An intervertebral fusion cage, comprising:

[0006] Axis;

[0007] A first spreading member, mounted on the shaft and capable of moving axially along the shaft, the first spreading member having an inner end and an outer end distributed radially along the shaft, the inner end being connected to the shaft; and

[0008] The fusion body is circumferentially arranged around the shaft and connected to the outer end of the first support member. A first slide is provided on the inner wall of the fusion body. An angle is provided between the extension direction of the first slide and the outer wall of the fusion body. The outer end of the first support member is movably arranged in the first slide.

[0009] In the aforementioned intervertebral fusion device, the first distraction member slides along the first slideway to change the distance between the fusion body and the shaft body, thereby varying the size of the distraction device. When implanted in the patient's area, the distraction range of the device can be adjusted based on the specific conditions of the intervertebral space, increasing the contact surface with the intervertebral space for better adaptation and matching, while also maintaining the height of the intervertebral space and restoring the physiological curvature of the lumbar spine. Furthermore, the device's closed volume prior to implantation is relatively small, meeting the volume requirements of different surgical approaches (anterior, posterior, and transforaminal).

[0010] In one embodiment, the first support member includes a first thread ring and a plurality of first support rods. The first thread ring is sleeved on the shaft and threadedly connected to the shaft. The first support rod connects the first thread ring and the first slideway.

[0011] In one embodiment, a plurality of first support rods are circumferentially arranged around the thread ring, and a plurality of first slideways are provided, and are arranged in one-to-one correspondence with the first support rods.

[0012] In one embodiment, a plurality of the first support rods are circumferentially and evenly arranged around the first thread circle.

[0013] In one embodiment, the first support rod includes a first body and a first shaft rod, the first body is connected to the first shaft rod and the first thread ring, and the first shaft rod is disposed in the first slideway.

[0014] In one embodiment, inner walls on both sides of the first slideway are extended with bent portions, and the two bent portions extend in directions approaching each other, and the outer end of the first support member is clamped in the first slideway and abuts against the bent portions.

[0015] In one embodiment, the outer end of the first expansion member is in interference connection with the first slideway.

[0016] In one embodiment, the first slideway has an inner end and an outer end distributed in the longitudinal direction of the shaft body, and the first slideway gradually approaches the shaft body from the outer end of the first slideway to the inner end of the first slideway.

[0017] In one embodiment, the inner wall of the fusion body is further provided with an avoidance groove, the avoidance groove is parallel to the shaft body, and a portion of the shaft body is accommodated in the avoidance groove.

[0018] In one embodiment, a second support member is further included. The second support member has the same structure as the first support member. The second support member is installed on the shaft body. The inner wall of the fusion body is also provided with a second slide. The extension direction of the second slide is provided with an angle with the outer wall of the fusion body. The second slide and the first slide are centrally symmetrically arranged about the midpoint of the shaft body, and the outer end of the second support member is movably arranged in the second slide.

[0019] In one embodiment, a first thread and a second thread are respectively provided at both ends of the shaft, the first thread and the second thread have opposite rotation directions, the first support member is threadedly connected to the first thread, and the second support member is threadedly connected to the second thread.

[0020] In one embodiment, the pitch of the first thread is greater than the pitch of the second thread.

[0021] In one embodiment, a limiting section is provided between the first thread and the second thread of the shaft, and the limiting section can limit the movement of the first support member or the second support member.

[0022] In one embodiment, the second slideway has an inner end and an outer end distributed in the longitudinal direction of the shaft body, and the second slideway gradually approaches the shaft body from the outer end of the second slideway to the inner end of the second slideway.

[0023] In one embodiment, the shaft body includes a first shaft body and a second shaft body, the first shaft body and the second shaft body are coaxial and spaced apart, the first shaft body is provided with a first operating hole extending along the axial direction of the first shaft body and passing through, the second shaft body is provided with a second operating hole, the second operating hole is arranged opposite to the first operating hole, and also includes a second support member with the same structure as the first support member, the fusion body is also provided with a second slide, the extension direction of the second slide is provided with an angle with the outer wall of the fusion body, and the outer end of the second support member is movably arranged in the second slide.

[0024] In one embodiment, the first shaft is provided with a thread, and the second shaft is provided with a thread, and the thread of the first shaft is opposite to the thread of the second shaft.

[0025] In one embodiment, the fusion body includes four fusion parts, and the four fusion parts are circumferentially arranged around the shaft and at intervals.

[0026] In one embodiment, teeth are provided on two opposite sides of the fusion body.

[0027] In one embodiment, the fusion body has a hollow structure inside.

[0028] In one embodiment, at least a portion of the outer wall of the fusion body is provided with hollow holes to communicate with the hollow structure inside the fusion body, and the hollow structure is at a predetermined distance from the inner wall of the fusion body. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of an intervertebral fusion cage according to one embodiment;

[0030] Figure 2 For example Figure 1 A schematic structural diagram of the first distraction member in the intervertebral fusion cage is shown;

[0031] Figure 3 For example Figure 1The schematic diagram of the structure of the fusion part in the intervertebral fusion cage is shown;

[0032] Figure 4 For example Figure 1 The fusion portion and the first distraction member of the intervertebral fusion cage are assembled;

[0033] Figure 5 For example Figure 1 A cross-sectional view of the fusion portion of the intervertebral fusion cage shown;

[0034] Figure 6 For example Figure 1 A side view of the intervertebral fusion cage in the deployed state is shown;

[0035] Figure 7 For example Figure 1 A side view of the intervertebral fusion cage in a closed state is shown;

[0036] Figure 8 For example Figure 1 A schematic structural diagram of the second distraction member in the intervertebral fusion cage shown;

[0037] Figure 9 A side view of an intervertebral fusion cage in an expanded state according to another embodiment;

[0038] Figure 10 For example Figure 1 The schematic diagram of the structure of the fusion part in the intervertebral fusion cage is shown;

[0039] Figure 11 For example Figure 1 Schematic diagram of the working state of the intervertebral fusion cage shown. DETAILED DESCRIPTION

[0040] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0041] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] See also Figure 1 An intervertebral fusion device 10 in one embodiment is used to expand, compress and stabilize the diseased intervertebral space. The intervertebral fusion device 10 includes a shaft body 100, a first expansion member 200 and a fusion body 300. The first expansion member 200 is mounted on the shaft body 100, and the first expansion member 200 can move along the axial direction of the shaft body 100. The first expansion member 200 has an inner end and an outer end distributed along the radial direction of the shaft body 100. The fusion body 300 is circumferentially arranged around the shaft body 100 to surround the shaft body 100 and the first expansion member 200, and is connected to the outer end of the first expansion member 200. A first slide 310 is provided on the inner wall of the fusion body 300 close to the shaft body 100, and an angle is formed between the extension direction of the first slide 310 and the outer wall of the fusion body 300. The outer end of the first expansion member 200 is movably disposed in the first slideway 310 . The first expansion member 200 slides along the first slideway 310 to change the distance between the inner wall of the fusion body 300 and the shaft body 100 , thereby changing the expansion size of the intervertebral fusion cage 10 .

[0044] In the intervertebral fusion cage 10, the first distraction member 200 slides along the first slideway 310 to change the distance between the fusion body 300 and the shaft body 100, thereby varying the extent of the distraction of the intervertebral fusion cage 10. When implanted in the patient's area, the distraction range of the intervertebral fusion cage 10 can be adjusted based on the specific conditions of the intervertebral space, increasing the contact surface with the intervertebral space for better adaptation and matching, maintaining the height of the intervertebral space and restoring the physiological curvature of the lumbar spine. Furthermore, the intervertebral fusion cage 10 is in a closed state prior to implantation, resulting in a relatively small overall size, which can meet the volume requirements of different surgical approaches (anterior, posterior, and transforaminal).

[0045] In one embodiment, the fusion body 300 includes four fusion parts 320, which are arranged circumferentially and at intervals around the shaft body 100. Each fusion part 320 is provided with a first slideway 310. The first expansion member 200 extends into the four first slideways 310. The fusion part 320 is connected to the shaft body 100 through the first expansion member 200. Figure 2Specifically, the first expansion member 200 includes a first threaded ring 210 and four first support rods 220. The first threaded ring 210 is sleeved on the shaft body 100 and threadedly connected to the shaft body 100. The four first support rods 220 are evenly arranged around the first threaded ring 210 to form a cross shape. The four first support rods 220 are arranged in a one-to-one correspondence with the four first slideways 310, thereby connecting the fusion portion 320 to the shaft body 100.

[0046] See also Figures 3 to 5 The inner walls on both sides of the first slide 310 extend with first bending portions 330, and the two first bending portions 330 extend in a direction close to each other. The outer end of the first expansion member 200 is clamped in the first slide 310 and abuts against the first bending portion 330. Figure 2 The first support rod 220 includes a first body 221 and a first shaft 222. The first slideway 310 has a T-shaped cross-section. The first shaft 222 is mounted within the first slideway 310, abutting against the bottom wall of the first slideway 310 and the first bent portion 330, respectively. The first body 221 connects the first shaft 222 and the first threaded ring 210. The first shaft 222 is cylindrical and fixedly connected to the end of the first body 221 away from the first threaded ring 210. The fusion portion 320 can rotate about the first shaft 222, allowing it to be opened by the first opening member 200. The cross-shaped first expansion member 200 cooperates with the first slide 310. At the same time, the four fusion parts 320 have the same structure, and the adjacent or opposite fusion parts 320 in the four fusion parts 320 are symmetrically arranged. This can make the four fusion parts 320 more evenly deployed after the fusion device is expanded, occupy a larger space after expansion, and provide better support for the vertebral body. It should also be noted that the first main body 221 is interference-connected with the first slide 310 and has a certain resistance to movement, which prevents the first expansion member 200 from sliding along the first slide 310 under the action of gravity. In this embodiment, the material of the fusion body 300 can be titanium alloy, tantalum alloy, or high molecular weight polyetheretherketone. In addition, matching first slides 310 and first support rods 220 can be set according to the number of fusion bodies 300.

[0047] In one embodiment, the inner wall of the fusion portion 320 is further provided with an avoidance groove 340, which is parallel to the shaft body 100 and partially accommodates the shaft body 100. At the same time, the avoidance groove is configured to match the shape of the shaft body 100 and is set to an arc shape to reduce rotation resistance.

[0048] See also Figure 6 and Figure 7In one embodiment, the intervertebral fusion cage 10 further includes a second spacer 400. The second spacer 400 and the first spacer 200 are respectively threadedly connected to the ends of the shaft body 100. Specifically, the shaft body 100 is provided with a first thread 110 to match the first spacer 200, and the shaft body 100 is further provided with a second thread 120 to match the second spacer 400. The first thread 110 and the second thread 120 are respectively provided at the upper and lower ends of the shaft body 100. The first thread 110 and the second thread 120 have opposite rotation directions, with the first thread 110 being a right-hand thread and the second thread 120 being a left-hand thread. The pitch of the first thread 110 is greater than the pitch of the second thread 120. When the shaft body 100 rotates clockwise, the first support member 200 and the second support member 400 will move toward each other along the center line of the shaft body 100. When the shaft body 100 rotates counterclockwise, the first support member 200 and the second support member 400 will move away from each other along the two ends of the shaft body 100.

[0049] Furthermore, combined with Figure 4The fusion portion 320 further defines a second slideway 350, and the end of the second expansion member 400 away from the shaft body 100 is disposed in the second slideway 350. The first slideway 310 and the second slideway 350 are respectively disposed at the two ends of the fusion portion 320. An angle is formed between the extension line of the second slideway 350 and the shaft body 100. The first slideway 310 has an inner end and an outer end distributed along the longitudinal direction of the shaft body 100. From the outer end of the first slideway 310 to the inner end of the first slideway 310, the first slideway 310 gradually tilts toward the shaft body 100 to approach the shaft body 100. From the top of the shaft body 100 to the centerline of the shaft body 100, the distance between the inner wall of the first slideway 310 and the shaft body 100 gradually decreases. Correspondingly, the second slide 350 has an inner end and an outer end distributed along the longitudinal direction of the shaft body 100. Along the direction from the outer end of the second slide 350 to the inner end of the second slide 350, the second slide 350 gradually tilts toward the shaft body 100 to approach the shaft body 100. Along the direction from the bottom of the shaft body 100 to the center line of the shaft body 100, the distance from the inner wall of the second slide 350 to the shaft body 100 gradually decreases. With this arrangement, the shaft 100 is rotated to expand the intervertebral fusion cage 10. The first and second expanders 200 and 400 simultaneously move from opposite ends of the shaft 100 toward its midline to expand the ends of the intervertebral fusion cage 10. Because the pitch of the first thread 110 is greater than the pitch of the second thread 120, the first expander 200 moves faster and covers a greater distance, causing the first expander 200 to expand the top of the intervertebral fusion cage 10 to expand more than the second expander 400 expands the bottom of the intervertebral fusion cage 10. Specifically, the expansion of the top of the intervertebral fusion cage 10 is 1.5 times the expansion of the bottom of the cage. The side view of the expanded intervertebral fusion cage 10 is trapezoidal. The normal lumbar intervertebral space is wide in front and narrow in the back. The expansion of the intervertebral fusion cage 10 at both ends in this embodiment allows it to match the normal vertebral space after implantation, thereby restoring the original physiological curvature of the lumbar spine at the implantation site.

[0050] See also Figure 8 More specifically, the second support member 400 includes a second thread ring 410 and four second support rods 420. The second thread ring 410 is sleeved on the shaft body 100 and threadedly connected to the shaft body 100. The four second support rods 420 are circumferentially and evenly arranged around the second thread ring 410 to form a cross shape.

[0051] Combine Figure 3, second bends 430 extend from the inner walls on both sides of the second slide 350, and the two bends 430 extend in a direction approaching each other. The outer end of the second expansion member 400 is clamped in the second slide 350 and abuts against the second bends 430. The second support rod 420 includes a second main body 421 and a second shaft 422. The cross-section of the second slide 350 is "T"-shaped. The second shaft 422 is clamped in the second slide 350 and abuts against the bottom wall of the second slide 350 and the second bend 430, respectively. The second main body 421 connects the second shaft 422 and the second thread ring 410. The second shaft body 100 is cylindrical and fixedly connected to the end of the second main body 421 away from the second thread ring 410. The fusion part 320 can rotate around the second shaft 422, so that the fusion part 320 can be expanded under the drive of the second expansion member 400. The four second support rods 420 are arranged in a one-to-one correspondence with the four second slideways 350 to connect the fusion portion 320 and the shaft body 100. The pitch of the second thread ring 410 is smaller than the pitch of the first thread ring 210. The second thread ring 410 is adapted to the second thread 120 to ensure that the moving distances of the first support member 200 and the second support member 400 are different. It should be noted that, again refer to Figure 1 The end of the shaft body 100 is provided with an operating hole 130. In this embodiment, the operating hole 130 is cross-shaped and can be rotated by a workpiece matching the shape of the operating hole 130. In other embodiments, the operating hole 130 can also be a regular hexagon, a plum blossom, or the like.

[0052] In one embodiment, the second slide 350 and the first slide 310 are centrally symmetrically arranged about the midpoint of the shaft 100 , so that the first distraction member 200 and the second distraction member 400 can maintain synchronization and stability during movement to ensure the distraction effect of the intervertebral fusion cage 10 .

[0053] See also Figure 6 In one embodiment, a limiting section 140 is provided between the first thread 110 and the second thread 120 on the shaft body 100. No thread is provided on the limiting section 140. When the first support member 200 or the second support member 400 moves to the limiting section 140, it will no longer be able to move further. The limiting section 140 can limit the moving range of the first support member 200 or the second support member 400 to avoid collision between the first support member 200 and the second support member 400.

[0054] See also Figure 9In one embodiment, to more freely adjust the degree of distraction at both ends of the intervertebral fusion cage, the shaft 100 is configured as a first shaft 150 and a second shaft 160 spaced apart, with the first shaft 150 and the second shaft 160 coaxially arranged. A first distraction member 200 is threadedly connected to the first shaft 150. Rotation of the first shaft 150 drives the first distraction member 200 along the first slide 310. The downward movement of the first distraction member 200 distracts the upper end of the intervertebral fusion cage 10. A second distraction member 400 is threadedly connected to the second shaft 160. Rotation of the second shaft 160 drives the second distraction member 400 along the second slide 350. The upward movement of the second distraction member 400 distracts the lower end of the intervertebral fusion cage 10. The first shaft body 150 is provided with a first operating hole (not shown), which extends along the axial direction of the first shaft body 150 and penetrates the first shaft body 150. The second shaft body 160 is provided with a second operating hole (not shown), which extends along the axial direction of the second shaft body 160 and penetrates the second shaft body 160. The first operating hole and the second operating hole are arranged opposite to each other. In this embodiment, the first operating hole and the second operating hole can both be set to a cross shape, and rotated by a workpiece of matching shape. When it is necessary to drive the movement of the first support member 200, the workpiece is inserted into the first operating hole and rotated to rotate the first shaft body 150. When it is necessary to drive the movement of the second support member 400, the movable member is inserted into the first operating hole, and then extends through the first operating hole into the second operating hole to rotate the second shaft body 160. It should be noted that in this embodiment, the material of the fusion body 300 should be selected from a material with a certain deformation ability, such as a polyurethane material.

[0055] In one embodiment, a limited segment 140 is provided on one end of the first shaft 150 close to the second shaft 160, and correspondingly, a limited segment 140 is provided on one end of the second shaft 160 close to the first shaft 150 to limit the travel of the first support member 200 and the second support member 400 respectively.

[0056] See also Figure 10In one embodiment, teeth-like portions 500 are provided on two opposite sides of the fusion body 300. Specifically, the teeth-like portion 500 is provided on the end surface of the fusion portion 320 that contacts the vertebral body. The teeth-like portion 500 may be in the shape of saw teeth, which can increase the friction with the contact surface, thereby enhancing stability and preventing movement of the fusion device after implantation. It should be noted that, in this embodiment, the fusion portion 320 is in the shape of a step, and the teeth-like portion 500 is provided on the inclined surface of the step. In other embodiments, the fusion portion 320 may be in the shape of a cuboid, a cylinder, etc., and the teeth-like portion 500 is correspondingly provided on the side that contacts the vertebral body. The interior of the fusion portion 320 has a hollow structure, and the hollow fusion portion 320 can store more allogeneic bone powder. Specifically, a hollow layer 600 is provided in the fusion part 320, and the hollow layer 600 includes a relatively arranged hollow surface 610 and a bottom surface (not shown in the figure). The hollow surface 610 is provided on the outer wall of the fusion part 320, and a plurality of hollow holes are opened on the outer wall of the fusion part 320 to form the hollow surface 610. The hollow surface 610 is spaced apart from the toothed part 500, and the bottom surface is arranged opposite to the hollow surface 610. A cavity 620 is provided between the hollow surface 610 and the bottom surface, which can ensure that allogeneic bone powder is captured to a large extent, promote the induction of bone tissue growth into the pores, promote intervertebral fusion, enhance the mechanical locking of the intervertebral fusion device 10, and thus obtain a better long-term fixation effect. The bottom surface is spaced a predetermined distance from the inner wall of the fusion portion 320, preventing the inner walls of the first slideway 310 and the second slideway 350 from being hollow structures. This ensures stability when the first spreader 200 and the second spreader 400 slide in the first slideway 310 and the second slideway 350, respectively. In other embodiments, the teeth 500 can be circumferentially arranged on the fusion portion 320. This eliminates the need to deliberately tilt the teeth 500 so that they face the vertebral body during implantation of the intervertebral fusion cage 10, allowing for greater flexibility during implantation. Furthermore, to accommodate allogeneic bone powder, both teeth and a hollow surface 610 are provided on the end surface of the fusion portion 320.

[0057] It should be noted that the intervertebral fusion cage 10 of this embodiment has a simple internal structure. By replacing different shaft bodies 100, first distraction members 200 and second distraction members 400, it can meet the personalized needs of patients with different degrees of lesions for distracting different areas of the intervertebral space at different heights or angles, greatly improving the scope of application.

[0058] See also Figure 11The intervertebral fusion cage 10 is implanted into the intervertebral space 11. The initial contact between the vertebral body 12 and the intervertebral fusion cage 10 will squeeze the intervertebral fusion cage 10. The intervertebral fusion cage 10 is then appropriately expanded according to the size of the intervertebral space 11. Due to the force exerted by the vertebral body 12 on the intervertebral fusion cage 10, the first and second expanders 200 and 400 will move on the shaft 100 when the workpiece rotates the shaft 100. Specifically, when the workpiece rotates toward the proximal end of the shaft 100, the first and second expanders 200 and 400 will move toward the middle of the shaft 100 along the shaft 100. Since the first expander 200 moves faster, the proximal end of the intervertebral fusion cage 10 is expanded to a larger size, matching the normal lumbar intervertebral space 11, which is wide in front and narrow in the back, so as to expand, compress, and stabilize the diseased intervertebral space 11.

[0059] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An intervertebral fusion cage, characterized in that: include: Axis; a first spreading member, mounted on the shaft body and capable of moving axially along the shaft body, the first spreading member having an inner end and an outer end distributed in the radial direction of the shaft body, the inner end being connected to the shaft body; and a fusion body, circumferentially arranged around the shaft and connected to the outer end of the first expansion member; a first slideway is provided on the inner wall of the fusion body; an angle is formed between the extension direction of the first slideway and the outer wall of the fusion body; the outer end of the first expansion member is movably disposed in the first slideway; The fusion body further includes a second expansion member having the same structure as the first expansion member, the second expansion member being mounted on the shaft, the inner wall of the fusion body further being provided with a second slideway, the extension direction of the second slideway being at an angle to the outer wall of the fusion body, the second slideway being centrally symmetrically arranged with the first slideway about the midpoint of the shaft, and the outer end of the second expansion member being movably disposed in the second slideway; The shaft body is provided with a first thread and a second thread at both ends, the first thread and the second thread have opposite rotation directions, the first expansion member is threadedly connected to the first thread, and the second expansion member is threadedly connected to the second thread; the pitch of the first thread is greater than the pitch of the second thread; The fusion body includes a fusion part that is circumferentially arranged around the shaft and at intervals, a hollow layer is provided in the fusion part, the hollow layer includes a hollow surface and a bottom surface that are relatively arranged, a plurality of hollow holes are opened on the outer wall of the fusion part to form a hollow surface, the hollow surface is spaced apart from the tooth-shaped part, the bottom surface is arranged opposite to the hollow surface, a cavity is provided between the hollow surface and the bottom surface, and the bottom surface has a predetermined distance from the inner wall of the fusion part.

2. The intervertebral fusion cage according to claim 1, characterized in that: The first support member includes a first thread ring and a plurality of first support rods. The first thread ring is sleeved on the shaft and threadedly connected to the shaft. The first support rod connects the first thread ring and the first slideway.

3. The intervertebral fusion cage according to claim 2, characterized in that: A plurality of first support rods are circumferentially arranged around the thread ring, and a plurality of first slideways are provided, and are arranged in one-to-one correspondence with the first support rods.

4. The intervertebral fusion cage according to claim 2, characterized in that: A plurality of first support rods are circumferentially and evenly arranged around the first thread circle.

5. The intervertebral fusion cage according to claim 2, wherein: The first support rod includes a first body and a first shaft rod, the first body is connected to the first shaft rod and the first thread ring, and the first shaft rod is arranged in the first slideway.

6. The intervertebral fusion cage according to claim 1, characterized in that: Bending portions extend from the inner walls on both sides of the first slideway, and the two bending portions extend in directions approaching each other. The outer end of the first expansion member is clamped in the first slideway and abuts against the bending portions.

7. The intervertebral fusion cage according to claim 1, characterized in that: The outer end of the first expansion member is interference-connected with the first slideway.

8. The intervertebral fusion cage according to claim 1, wherein: The first slideway has an inner end and an outer end distributed in the longitudinal direction of the shaft body. From the outer end of the first slideway to the inner end of the first slideway, the first slideway gradually approaches the shaft body.

9. The intervertebral fusion cage according to claim 1, characterized in that: The inner wall of the fusion body is further provided with an avoidance groove, which is parallel to the shaft body, and a portion of the shaft body is accommodated in the avoidance groove.

10. The intervertebral fusion cage according to claim 1, wherein: A limiting section is provided between the first thread and the second thread of the shaft, and the limiting section can limit the movement of the first spreading member or the second spreading member.

11. The intervertebral fusion cage according to claim 1, characterized in that: The second slideway has an inner end and an outer end distributed in the longitudinal direction of the shaft body. From the outer end of the second slideway to the inner end of the second slideway, the second slideway gradually approaches the shaft body.

12. The intervertebral fusion cage according to any one of claims 1 to 9, characterized in that: The shaft body includes a first shaft body and a second shaft body, the first shaft body and the second shaft body are coaxial and spaced apart, the first shaft body is provided with a first operating hole extending along the axial direction of the first shaft body and passing through, the second shaft body is provided with a second operating hole, the second operating hole is arranged opposite to the first operating hole, and also includes a second support member with the same structure as the first support member, the fusion body is also provided with a second slide, the extension direction of the second slide is provided with an angle with the outer wall of the fusion body, and the outer end of the second support member is movably arranged in the second slide.

13. The intervertebral fusion cage according to claim 12, characterized in that: The first shaft body is provided with a thread, and the second shaft body is provided with a thread, and the thread of the first shaft body and the thread of the second shaft body have opposite rotation directions.

14. The intervertebral fusion cage according to claim 1, characterized in that: The fusion body includes four fusion parts, and the four fusion parts are arranged circumferentially around the shaft body and at intervals.

15. The intervertebral fusion cage according to claim 1, characterized in that: Two opposite sides of the fusion body are provided with teeth.

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