CN110755181A

CN110755181A - Intervertebral fusion device

Info

Publication number: CN110755181A
Application number: CN201911122239.5A
Authority: CN
Inventors: 邹丽敏; 杨海东; 孙君; 李顺锋; 李想
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2020-02-07

Abstract

The invention relates to an interbody fusion cage which comprises a shaft body, a first spreading piece and a fusion body, wherein the first spreading piece is arranged on the shaft body and can move along the axial direction of the shaft body, the first spreading piece is provided with an inner end and an outer end which are distributed along the radial direction of the shaft body, the inner end is connected with the shaft body, the fusion body is arranged around the circumferential direction of the shaft body and is connected with the outer end of the first spreading piece, a first slide way is arranged on the inner wall of the fusion body, an included angle is formed between the extending direction of the first slide way and the outer wall of the fusion body, and the outer end of the first spreading piece is movably arranged in the first slide way. Among the above-mentioned interbody fusion cage, first piece of strutting can change the distance between fusion body and the axis body along first slide slip to change interbody fusion cage size of strutting, can adjust interbody fusion cage's the scope of strutting according to the particular case in intervertebral space when interbody fusion cage implants, increase and the contact surface in intervertebral space in order to the better matching in intervertebral space, and maintained the height in intervertebral space, recovered the physiological curvature of lumbar vertebrae.

Description

Intervertebral fusion device

Technical Field

The invention relates to the field of medical instruments, in particular to an intervertebral fusion cage.

Background

Degenerative lumbar diseases (including lumbar spinal stenosis, lumbar spondylolisthesis, degenerative lateral curvature, disc-derived diseases and the like) and structural damage thereof are important causes of pain in the waist and lower extremities, and damage and even loss of sensory and motor functions of a human body, and the treatment principle is to relieve nerve compression and reconstruct the stability of the spine. The intervertebral fusion cage is implanted into the affected part of the intervertebral disease to expand, compress and stabilize the damaged intervertebral space, and has gradually developed into a standard means for treating the lumbar degenerative disease.

Due to the special physiological structure of the lumbar intervertebral space, after the conventional intervertebral fusion cage is implanted into the intervertebral space, the two requirements of recovering the intervertebral space height and increasing the contact surface of the fusion cage and the upper and lower final plates are difficult to meet simultaneously, and the treatment effect after the operation is influenced.

Disclosure of Invention

Therefore, the intervertebral fusion device has high matching degree with the lumbar intervertebral space and good fusion effect of the vertebral body space.

An intervertebral cage comprising:

a shaft body;

the first spreading piece is arranged on the shaft body and can move along the axial direction of the shaft body, the first spreading piece is provided with an inner end and an outer end which are distributed along the radial direction of the shaft body, and the inner end is connected with the shaft body; and

the fusion body is arranged around the circumference of the shaft body and is connected with the outer end of the first opening piece, a first slide way is arranged on the inner wall of the fusion body, an included angle is formed between the extending direction of the first slide way and the outer wall of the fusion body, and the outer end of the first opening piece is movably arranged in the first slide way.

Among the above-mentioned interbody fusion cage, first piece of strutting can change the distance between fusion body and the axis body along first slide slip to change interbody fusion cage size of strutting, can adjust interbody fusion cage's the scope of strutting according to the particular case in intervertebral space when interbody fusion cage implants the sick affected part, increase and the contact surface in intervertebral space with the adaptation and the matching better to intervertebral space, still maintained the height in intervertebral space, recovered lumbar vertebrae physiology curvature. Meanwhile, the intervertebral fusion cage has smaller closed volume before being implanted, and can meet the requirements of different operation approaches (anterior approach, posterior approach and transforaminal approach) on the volume of the intervertebral fusion cage.

In one embodiment, the first spreader includes a first thread ring and a plurality of first struts, the first thread ring is sleeved on the shaft and is in threaded connection with the shaft, and the first struts are connected with the first thread ring and the first slideway.

In one embodiment, a plurality of first supporting rods are circumferentially arranged around the thread ring, and a plurality of first slideways are arranged and correspond to the first supporting rods one to one.

In one embodiment, the first support rods are circumferentially and uniformly arranged around the first thread turn.

In one embodiment, the first support rod includes a first body and a first shaft rod, the first body connects the first shaft rod and the first thread ring, and the first shaft rod is disposed in the first slideway.

In one embodiment, the inner walls of the two sides of the first slide way extend to form bending portions, the two bending portions extend in the direction close to each other, and the outer end of the first spreading member is clamped in the first slide way and abutted against the bending portions.

In one embodiment, the outer end of the first spreader is in interference fit with the first runner.

In one embodiment, the first slideway has an inner end and an outer end distributed along the longitudinal direction of the shaft body, and the first slideway is gradually close to the shaft body along the direction from the outer end of the first slideway to the inner end of the first slideway.

In one embodiment, the inner wall of the fusion body is further provided with an avoiding groove, the avoiding groove is parallel to the shaft body, and part of the shaft body is accommodated in the avoiding groove.

In one embodiment, the portable folding device further comprises a second spreading member, the second spreading member and the first spreading member have the same structure, the second spreading member is mounted on the shaft body, a second slide way is further formed in the inner wall of the fusion body, an included angle is formed between the extending direction of the second slide way and the outer wall of the fusion body, the second slide way and the first slide way are arranged in central symmetry about the midpoint of the shaft body, and the outer end of the second spreading member is movably arranged in the second slide way.

In one embodiment, a first thread and a second thread are respectively arranged at two ends of the shaft body, the turning directions of the first thread and the second thread are opposite, the first spreading member is in threaded connection with the first thread, and the second spreading member is in threaded connection with the second thread.

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

In one embodiment, a limiting section is arranged between the first thread and the second thread of the shaft body, and the limiting section can limit the movement of the first spreading piece or the second spreading piece.

In one embodiment, the second slideway has an inner end and an outer end distributed along the longitudinal direction of the shaft body, and the second slideway is gradually close to the shaft body along the direction from the outer end of the second slideway to the inner end of the second slideway.

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 coaxially arranged at intervals, the first shaft body is provided with a first operation hole which extends along the axial direction of the first shaft body and is through, the second shaft body is provided with a second operation hole, the second operation hole is opposite to the first operation hole, the shaft body further includes a second opening member which has the same structure as the first opening member, the fusion body is further provided with a second slide way, an included angle is formed between the extending direction of the second slide way and the outer wall of the fusion body, and the outer end of the second opening member is movably arranged in the second slide way.

In one embodiment, the first shaft body is provided with threads, the second shaft body is provided with threads, and the threads of the first shaft body and the threads of the second shaft body are opposite in rotation direction.

In one embodiment, the fusion body comprises four fusion portions, and the four fusion portions are arranged around the shaft body at intervals.

In one embodiment, the fusion body is provided with teeth on two opposite sides.

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

In one embodiment, at least part of the outer wall of the fusion body is provided with a hollowed hole to communicate with a hollowed structure inside the fusion body, and the hollowed structure has a predetermined distance from the inner wall of the fusion body.

Drawings

FIG. 1 is a schematic view of an embodiment of an intervertebral cage;

FIG. 2 is a schematic view of a first distractor of the intervertebral cage of FIG. 1;

FIG. 3 is a schematic view of the fusion portion of the intervertebral cage of FIG. 1;

FIG. 4 is an assembly view of the fusion portion and the first distractor of the intervertebral cage shown in FIG. 1;

FIG. 5 is a cross-sectional view of a fusion in the intervertebral cage of FIG. 1;

FIG. 6 is a side view of the intervertebral cage of FIG. 1 in an expanded configuration;

FIG. 7 is a side view of the cage of FIG. 1 in a closed position;

FIG. 8 is a schematic view of a second distractor of the intervertebral cage of FIG. 1;

FIG. 9 is a side view of another embodiment interbody cage in an expanded state;

FIG. 10 is a schematic view of a fusion portion of the intervertebral cage of FIG. 1;

fig. 11 is a schematic view of the intervertebral cage of fig. 1 in an operational state.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, one embodiment of an interbody cage 10 is used to distract, compress, and stabilize a damaged intervertebral space. The intervertebral fusion device 10 includes a shaft body 100, a first distraction member 200 and a fusion body 300, wherein the first distraction member 200 is mounted on the shaft body 100, and the first distraction member 200 can move along the axial direction of the shaft body 100. The first spreader 200 has inner and outer ends distributed in a radial direction of the shaft body 100. The fusion body 300 is circumferentially disposed around the shaft body 100 to surround the shaft body 100 and the first spreader 200, and is connected to an outer end of the first spreader 200. The inner wall of the fusion body 300 close to the shaft body 100 is provided with a first slide way 310, and an included angle is formed between the extending direction of the first slide way 310 and the outer wall of the fusion body 300. The outer end of the first spreader 200 is movably disposed in the first sliding channel 310, and the first spreader 200 slides along the first sliding channel 310 to change the distance between the inner wall of the fusion body 300 and the shaft body 100, thereby changing the spreading size of the intervertebral fusion device 10.

Among the above-mentioned interbody fusion cage 10, first piece 200 of strutting can change the distance between fusion body 300 and the axis body 100 along first slide 310 slides to change the size that interbody fusion cage 10 struts, can adjust the scope of strutting of interbody fusion cage 10 according to the particular case in intervertebral space when interbody fusion cage 10 implants the sick part, increase and the contact surface in intervertebral space with better adaptation and the matching to the intervertebral space, still maintained the height in intervertebral space, recovered the physiological curvature of lumbar vertebrae. Meanwhile, the intervertebral fusion cage 10 is in a closed state before being implanted, has small overall volume, and can meet the requirements of different operation approaches (anterior approach, posterior approach and transforaminal approach) on the volume of the intervertebral fusion cage 10.

In one embodiment, the fusion body 300 includes four fusion portions 320, the four fusion portions 320 are circumferentially disposed around the shaft body 100 at intervals, each fusion portion 320 has a first sliding way 310, the first spreading member 200 extends into the four first sliding ways 310, and the fusion portion 320 is connected to the shaft body 100 through the first spreading member 200. Referring to fig. 2, in particular, the first spreader 200 includes a first thread ring 210 and four first struts 220, and the first thread ring 210 is sleeved on the shaft 100 and is in threaded connection with the shaft 100. The four first struts 220 are circumferentially and uniformly arranged around the first thread turn 210 to have a cross shape. The four first support bars 220 are disposed in one-to-one correspondence with the four first sliding ways 310, so as to connect the merging portion 320 with the shaft body 100.

Referring to fig. 3 to 5, the inner walls of the two sides of the first sliding channel 310 extend to form first bending portions 330, the two first bending portions 330 extend in the direction of approaching each other, and the outer end of the first spreading member 200 is clamped in the first sliding channel 310 and abuts against the first bending portions 330. Referring to fig. 2, the first supporting rod 220 includes a first main body 221 and a first shaft 222, the cross section of the first slide way 310 is "T" shaped, and the first shaft 222 is clamped in the first slide way 310 and is abutted against the bottom wall of the first slide way 310 and the first bending portion 330. The first body 221 connects the first shaft 222 and the first thread ring 210. The first shaft 222 is cylindrical and fixedly connected to an end of the first body 221 away from the first thread ring 210, and the fusion portion 320 can rotate around the first shaft 222, so that the fusion portion 320 can be expanded under the driving of the first spreader 200. The first piece 200 that struts of cruciform cooperatees with first slide 310, and simultaneously, four structures that fuse portion 320 are the same, and fuse portion 320 adjacent or relative in four fuse portion 320 and all be the symmetry setting, can make the fusion cage after strutting, four states that fuse portion 320 expandes are more even, and the shared space after the expansion is bigger, and is better to the support effect of centrum. It should be noted that the first body 221 is in interference connection with the first sliding channel 310, and has a certain moving resistance, so as to prevent the first spreader 200 from sliding along the first sliding channel 310 under the action of gravity. In this embodiment, the material of the fusion body 300 may be titanium alloy, tantalum alloy, or polymer polyetheretherketone. In addition, the matched first slide way 310 and the first supporting rod 220 can be arranged according to the number of the fusion bodies 300.

In one embodiment, the inner wall of the fusion portion 320 is further provided with an avoiding groove 340, the avoiding groove 340 is parallel to the shaft body 100, and a part of the shaft body 100 is accommodated in the avoiding groove 340. Meanwhile, the shape of the escape groove matching shaft body 100 is set to be a circular arc shape to reduce the rotational resistance.

Referring to fig. 6 and 7, in one embodiment, the intervertebral cage 10 further includes a second distractor 400. The second spreading member 400 and the first spreading member 200 are respectively screwed to two ends of the shaft 100. Specifically, the shaft body 100 is provided with a first thread 110 matching with the first spreader 200, the shaft body 100 is further provided with a second thread 120 matching with the second spreader 400, and the first thread 110 and the second thread 120 are respectively disposed at the upper end and the lower end of the shaft body 100. The first thread 110 and the second thread 120 are opposite in direction, the first thread 110 is a right-hand thread and the second thread 120 is a left-hand thread. The pitch of the first screw thread 110 is greater than that of the second screw thread 120, when the shaft body 100 rotates clockwise, the first spreading member 200 and the second spreading member 400 will move oppositely along the center line of the shaft body 100, and when the shaft body 100 rotates counterclockwise, the first spreading member 200 and the second spreading member 400 will move oppositely along the two end portions of the shaft body 100.

Further, with reference to fig. 4, the fusion portion 320 is further provided with a second sliding way 350, and an end of the second spreader 400 away from the shaft body 100 is disposed in the second sliding way 350. The first slideway 310 and the second slideway 350 are respectively arranged at two ends of the fusion part 320, an included angle is arranged between an extension line of the second slideway 350 and the shaft body 100, the first slideway 310 is provided with an inner end and an outer end which are distributed along the longitudinal direction of the shaft body 100, the first slideway 310 inclines towards the shaft body 100 gradually to be close to the shaft body 100 along the direction from the outer end of the first slideway 310 to the inner end of the first slideway 310, and the distance from the inner wall of the first slideway 310 to the shaft body 100 is gradually reduced along the direction from the top of the shaft body 100 to the central line of the shaft body 100. Correspondingly, the second slideway 350 has an inner end and an outer end distributed in the longitudinal direction of the shaft body 100, the second slideway 350 is gradually inclined toward the shaft body 100 to be close to the shaft body 100 along the direction from the outer end of the second slideway 350 to the inner end of the second slideway 350, and the distance from the inner wall of the second slideway 350 to the shaft body 100 is gradually reduced along the direction from the bottom of the shaft body 100 to the central line of the shaft body 100. So set up, the rotation axis body 100 struts the operation to interbody fusion cage 10, first piece 200 struts the piece 400 and removes from the both ends of axis body 100 towards the central line of axis body 100 simultaneously with the second, in order to strut the both ends of interbody fusion cage 10, because the pitch of first screw thread 110 is greater than the pitch of second screw thread 120, the speed that first piece 200 struts the removal is faster, the distance of removal will be bigger, make the degree that first piece 200 struts the top of interbody fusion cage 10 be greater than the degree that second piece 400 struts the bottom of interbody fusion cage 10, specifically, the size that the top of interbody fusion cage 10 struts is 1.5 times the size that the bottom of fusion cage struts, the side view after interbody fusion cage 10 expandes is trapezoidal. The normal lumbar intervertebral space is wide in the front and narrow in the back, and the intervertebral fusion cage 10 in the embodiment has two spread ends which can be matched with the normal vertebral body space after being implanted, so that the original lumbar physiological curvature is restored at the implanted position.

Referring to fig. 8, more specifically, the second spreader 400 includes a second thread ring 410 and four second struts 420, the second thread ring 410 is sleeved on the shaft 100 and is in threaded connection with the shaft 100, and the four second struts 420 are circumferentially and uniformly arranged around the second thread ring 410 to form a cross shape.

Referring to fig. 3, the inner walls of the two sides of the second slideway 350 extend to form second bending portions 430, the two bending portions 430 extend along the direction close to each other, and the outer ends of the second spreading members 400 are clamped in the second slideway 350 and abut against the second bending portions 430. The second support rod 420 includes a second main body 421 and a second shaft rod 422, the cross-section of the second slide way 350 is "T" shaped, and the second shaft rod 422 is clamped in the second slide way 350 and is abutted against the bottom wall of the second slide way 350 and the second bending portion 430, respectively. The second body 421 connects the second shaft 422 and the second thread ring 410. The second shaft 100 is cylindrical and is fixedly connected to an end of the second body 421 away from the second thread turn 410, and the fusion portion 320 can rotate around the second shaft 422, so that the fusion portion 320 can be spread by the second spreader 400. The four second struts 420 and the four second sliding ways 350 are disposed in a one-to-one correspondence to connect the fusion portion 320 and the shaft 100. The pitch of the second turn 410 is smaller than the pitch of the first turn 210, and the second turn 410 is fitted with the second thread 120, ensuring a difference in the moving distance of the first spreader 200 and the second spreader 400. It should be noted that, referring to fig. 1 again, the end of the shaft body 100 is provided with an operation hole 130, and in this embodiment, the operation hole 130 is cross-shaped and can rotate through a workpiece matching the shape of the operation hole 130. In other embodiments, the operation hole 130 may also be regular hexagonal, quincunx, or the like.

In one embodiment, the second sliding ways 350 and the first sliding ways 310 are arranged in a central symmetry manner about the midpoint of the shaft body 100, so that the first distraction member 200 and the second distraction member 400 can keep synchronicity and stability during movement, and the distraction effect of the intervertebral fusion device 10 can be ensured.

Referring to fig. 6, in one embodiment, a limiting section 140 is disposed between the first thread 110 and the second thread 120 on the shaft body 100, no thread is disposed on the limiting section 140, the first spreading member 200 or the second spreading member 400 cannot move any more when moving to the limiting section 140, and the limiting section 140 can limit the moving stroke of the first spreading member 200 or the second spreading member 400, so as to prevent the first spreading member 200 and the second spreading member 400 from colliding with each other.

Referring to fig. 9, in one embodiment, in order to adjust the degree of expansion of the two ends of the fusion cage more freely, the shaft bodies 100 are arranged as a first shaft body 150 and a second shaft body 160 which are arranged at an interval, the first shaft body 150 and the second shaft body 160 are arranged coaxially, the first expanding member 200 is in threaded connection with the first shaft body 150, the first shaft body 150 rotates to drive the first expanding member 200 to move along the first slideway 310, and the first expanding member 200 moves downward to expand the upper end of the intervertebral fusion cage 10. The second distraction piece 400 is in threaded connection with the second shaft body 160, the second shaft body 160 rotates to drive the second distraction piece 400 to move along the second slideway 350, and the second distraction piece 400 moves upwards to distract the lower end of the intervertebral fusion device 10. The first shaft 150 is provided with a first operation hole (not shown), the first operation hole extends along the axial direction of the first shaft 150 and penetrates through the first shaft 150, the second shaft 160 is provided with a second operation hole (not shown), the second operation hole extends along the axial direction of the second shaft 160 and penetrates through the second shaft 160, and the first operation hole and the second operation hole are arranged oppositely. In this embodiment, both the first operation hole and the second operation hole may be cross-shaped, and when the workpiece with a matching shape is rotated and the first spreader 200 needs to be driven to move, the workpiece is inserted into the first operation hole to rotate the first shaft 150. When the second spreader 400 needs to be driven to move, the movable member extends into the first operation hole, passes through the first operation hole, extends into the second operation hole, and rotates the second shaft 160. In this embodiment, the material of the fused body 300 should be a material with certain deformability, such as a polyurethane material.

In one embodiment, a position-limiting section 140 is disposed on an end of the first shaft 150 close to the second shaft 160, and correspondingly, a position-limiting section 140 is disposed on an end of the second shaft 160 close to the first shaft 150 to limit the strokes of the first spreader 200 and the second spreader 400 respectively.

Referring to fig. 10, in one embodiment, opposing faces of the fusion body 300 are provided with teeth 500. Specifically, the tooth-shaped portion 500 is disposed on the end surface of the fusion portion 320 contacting with the vertebral body, and the tooth-shaped portion 500 may have a saw-tooth shape, so as to increase the friction force with the contact surface, thereby enhancing the stability and preventing the fusion device from moving after being implanted. In the present embodiment, the fusion portion 320 is shaped as a step, and the tooth portion 500 is disposed on the inclined surface of the step. In other embodiments, the fusion portion 320 may be rectangular, cylindrical, etc. and the tooth portion 500 is disposed on a side of the vertebral body. The inside of the fusion part 320 has a hollow structure, and the hollow fusion part 320 can store more allogeneic bone powder. Specifically, the fusion portion 320 is provided with the hollow-out layer 600, the hollow-out layer 600 includes a hollow-out surface 610 and a bottom surface (not shown) which are oppositely arranged, the hollow-out surface 610 is arranged on the outer wall of the fusion portion 320, a plurality of hollow-out holes are formed in the outer wall of the fusion portion 320 to form the hollow-out surface 610, the hollow-out surface 610 and the tooth-shaped portion 500 are arranged at intervals, the bottom surface and the hollow-out surface 610 are oppositely arranged, and a cavity 620 is arranged between the hollow-out surface 610 and the bottom surface, so that allogeneic bone powder can be grasped to a large extent, the growth of induced bone tissues into the pores is promoted, the interbody fusion is promoted, the mechanical locking of the interbody fusion device 10 is enhanced, and a better long-term fixing effect is. The bottom surface has the given distance with the inner wall that fuses portion 320, avoids the inner wall of first slide 310, second slide 350 to be hollow out construction, has guaranteed the stability of first piece 200 of strutting when first slide 310 slides, second piece 400 of strutting slides at second slide 350. In other embodiments, the tooth-shaped portion 500 may be circumferentially disposed on the fusion portion 320, such that when the intervertebral fusion device 10 is implanted, the tooth-shaped portion 500 is not required to be turned over by an angle intentionally to be opposite to the vertebral body, and the implantation is more flexible, and meanwhile, in order to accommodate the bone allograft, the tooth-shaped portion and the hollowed-out surface 610 are disposed on the end surface of the fusion portion 320.

It should be noted that the intervertebral fusion cage 10 of the present embodiment has a simple internal structure, and can satisfy the individual requirements of different pathological degrees of the patient for distracting different regions of the intervertebral space at different heights or different angles by replacing the different shaft bodies 100, the first distracting member 200, and the second distracting member 400, thereby greatly improving the application range.

Referring to fig. 11, with the interbody cage 10 implanted in the intervertebral space 11, initial contact of the vertebral body 12 with the interbody cage 10 compresses the interbody cage 10. Then, the intervertebral cage 10 is properly expanded according to the size of the intervertebral space 11, and the first distractor 200 and the second distractor 400 will move on the shaft body 100 when the shaft body 100 is rotated by the work piece due to the force of the vertebral body 12 on the intervertebral cage 10. Specifically, the proximal end of the shaft body 100 is rotated by the workpiece, and the first spreading member 200 and the second spreading member 400 will approach toward the middle of the shaft body 100 along the shaft body 100 under the rotation of the shaft body 100, and the size of the proximal end of the interbody fusion cage 10 is larger due to the faster moving speed of the first spreading member 200, matching the normal lumbar intervertebral space 11 with wide front and narrow back, so as to spread, compress and stabilize the diseased intervertebral space 11.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An intervertebral cage, comprising:

a shaft body;

2. An intersomatic cage according to claim 1, wherein the first spreader includes a first threaded ring and a plurality of first struts, the first threaded ring being disposed around the shaft and being in threaded connection with the shaft, the first struts connecting the first threaded ring and the first runner.

3. An intersomatic cage according to claim 2, wherein a plurality of the first struts are circumferentially arranged around the threaded ring, and a plurality of the first runners are provided in one-to-one correspondence with the first struts.

4. An intersomatic cage according to claim 2, characterized in that a plurality of the first struts are arranged circumferentially and uniformly around the first turn of thread.

5. An intersomatic cage according to claim 2, wherein the first strut comprises a first body and a first shaft, the first body connecting the first shaft to the first threaded ring, the first shaft being disposed in the first slideway.

6. The intervertebral fusion cage of claim 1, wherein the inner walls of the two sides of the first slideway are extended with bending portions, and the two bending portions extend along directions close to each other, and the outer end of the first distraction piece is clamped in the first slideway and is abutted against the bending portions.

7. An intersomatic cage according to claim 1, wherein the outer end of the first spreader is in interference connection with the first slideway.

8. An intersomatic cage according to claim 1, characterized in that the first slideway has an inner end and an outer end distributed in the longitudinal direction of the shaft, the first slideway being progressively closer to the shaft in the direction from the outer end of the first slideway to the inner end of the first slideway.

9. An intersomatic cage according to claim 1, characterized in that the cage has an avoidance slot in its inner wall, parallel to the shaft, in which a part of the shaft is received.

10. The intersomatic cage according to any one of claims 1 to 9, further comprising a second spreader, the second spreader having a structure the same as that of the first spreader, the second spreader being mounted on the shaft, a second slideway being further formed in an inner wall of the fusion body, an included angle being formed between an extending direction of the second slideway and an outer wall of the fusion body, the second slideway and the first slideway being arranged in a central symmetry with respect to a midpoint of the shaft, and an outer end of the second spreader being movably disposed in the second slideway.

11. An intersomatic cage according to claim 10, wherein the shaft body has first and second threads at opposite ends thereof, the first and second threads being opposite in direction of rotation, the first distracting member being threadedly coupled to the first thread, and the second distracting member being threadedly coupled to the second thread.

12. An intersomatic cage according to claim 11, characterized in that the pitch of the first thread is greater than the pitch of the second thread.

13. An intersomatic cage according to claim 11, characterized in that a stop section is provided between the first and second threads of the shaft body, which stop section can limit the movement of the first or second distracting element.

14. An intersomatic cage according to claim 10, characterized in that the second slideway has an inner end and an outer end distributed in the longitudinal direction of the shaft, the second slideway being progressively closer to the shaft in the direction from the outer end of the second slideway to the inner end of the second slideway.

15. The intervertebral fusion device according to any one of claims 1 to 9, wherein the shaft body comprises a first shaft body and a second shaft body, the first shaft body and the second shaft body are coaxially arranged at intervals, the first shaft body is provided with a first operation hole extending in the axial direction of the first shaft body and penetrating through the first shaft body, the second shaft body is provided with a second operation hole, the second operation hole is arranged opposite to the first operation hole, the intervertebral fusion device further comprises a second distraction member having the same structure as the first distraction member, the fusion body is further provided with a second slideway, an included angle is formed between the extending direction of the second slideway and the outer wall of the fusion body, and the outer end of the second distraction member is movably arranged in the second slideway.

16. An intersomatic cage according to claim 15, characterized in that the first shaft is provided with a thread and the second shaft is provided with a thread, the threads of the first shaft being of opposite hand to the threads of the second shaft.

17. An intersomatic cage according to claim 1, wherein the fusion comprises four fusion portions arranged circumferentially and spaced around the shaft.

18. An intersomatic cage according to claim 1, characterized in that the opposite faces of the cage are provided with teeth.

19. An intersomatic cage according to claim 1, characterized in that the fusion has an hollowed-out structure inside.

20. An intersomatic cage according to claim 19, characterized in that the fusion has an outer wall at least partially provided with hollows for communicating with hollows inside the fusion, the hollows being at a determined distance from the inner wall of the fusion.