CN218792651U - Distractable intervertebral fusion device - Google Patents

Abstract

The utility model discloses a can strut interbody fusion cage belongs to orthopedic implant technical field, can strut interbody fusion cage includes the fusion cage main part, the top and/or the below of fusion cage main part are equipped with the body of strutting, be equipped with in the fusion cage main part and be used for the drive to strut the outside open distraction structure of body, the distraction structure is including the ejector pad that can follow fusion cage main part fore-and-aft direction and remove, the place ahead of ejector pad is equipped with the guide bar, be equipped with preceding guiding hole on the preceding lateral wall of fusion cage main part, the guide bar direction is installed in preceding guiding hole, be provided with between fusion cage main part and the guide bar and be used for carrying out spacing limit structure to guide bar axial motion. The utility model discloses a can strut interbody fusion cage can be convenient for carry on spacingly to the seesaw of guide bar, prevent that the guide bar from deviating from the fusion cage main part to be convenient for carry on spacingly to the seesaw of ejector pad, and then highly carry on spacingly to the strutting of the body that struts, make strut stably.

Description

Distractable intervertebral fusion device

Technical Field

The utility model relates to an orthopedic implant technical field especially indicates a can strut interbody fusion cage.

Background

The lumbar intervertebral fusion can effectively treat the characteristics of lumbar degeneration, instability and the like, can fuse the upper vertebral body and the lower vertebral body, maintain the intervertebral space height, relieve the pressure of nerve roots and maintain the stability of the vertebral column. The clinical effect is satisfactory, the operation wound is small, and the operation is convenient.

With the popularization of clinical application and the progress of theoretical research in recent years, the problems that the conventional fusion cage has certain defects, such as poor self-stability of an intervertebral implant, undesirable lumbar lordosis recovery after vertebral body fusion, and the like, are gradually found.

In order to solve the problems, the existing intervertebral fusion cage capable of being expanded is adopted, although the existing intervertebral fusion cage capable of being expanded on the market can effectively ensure the height of intervertebral space and relieve the symptoms of compression caused by vertebral bodies, the expanding structure is often too complex, and the phenomenon of unstable expansion exists.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a strutting intervertebral fusion cage which struts stably.

In order to solve the technical problem, the utility model provides a technical scheme as follows:

the utility model provides a can strut interbody fusion cage, includes the fusion cage main part, the top and/or the below of fusion cage main part are equipped with and prop open the body, be equipped with in the fusion cage main part and be used for the drive prop open the body outwards strutting structure, wherein:

the strutting structure comprises a push block capable of moving in the front-back direction of the fusion device main body, a guide rod is arranged in front of the push block, a front guide hole is formed in the front side wall of the fusion device main body, the guide rod is installed in the front guide hole in a guiding manner, and a limiting structure used for limiting the axial movement of the guide rod is arranged between the fusion device main body and the guide rod.

Furthermore, the limiting structure comprises an annular groove which is arranged on the outer side of the guide rod and extends along the axial direction of the guide rod, and a stop protrusion extending into the annular groove is arranged on the fusion device main body at a position corresponding to the annular groove.

Furthermore, a blind hole is formed in the position, corresponding to the annular groove, of the fusion device main body, and the bottom wall of the stop protrusion is formed by deforming towards the annular groove protrusion after the stop protrusion is punched by the blind hole;

or, the fusion cage main body is provided with a pin hole communicated with the front guide hole, a fixing pin is inserted into the pin hole, and the stopping bulge extends into the annular groove from the tail end of the fixing pin to form;

or the guide rod is detachably connected with the push block.

Furthermore, the opening structure further comprises a driving rod, a rear mounting hole is formed in the rear side wall of the fusion cage main body, the rear part of the driving rod is located in the rear mounting hole, the front part of the driving rod is in driving connection with the push block, and the push block is in driving connection with the opening body so as to drive the opening body to open outwards in the front and rear moving processes;

be equipped with vertical bone grafting cavity on the ejector pad, be equipped with in the actuating lever and follow the actuating lever length direction extends and with the bone grafting passageway that the bone grafting cavity is linked together, the rear end of actuating lever be equipped with the bone grafting passageway is linked together and supplies the inserted apparatus operation mouth of operating instrument.

Furthermore, an internal thread is arranged in the rear mounting hole, a thread section matched with the internal thread is arranged at the rear part of the driving rod, and the front part of the driving rod is rotatably assembled at the rear end of the push block to drive the push block to move along the front-back direction of the fusion device main body in the rotating process.

Furthermore, one of the matching parts of the push block and the driving rod is provided with a jack, and the other one of the matching parts of the push block and the driving rod is provided with a pin matched with the jack so that the driving rod is assembled on the push block in a rotating mode.

Furthermore, the middle of the plug pin is provided with a longitudinal cutting groove to enable the plug pin to be arranged in a split mode, and the outer side surfaces of the plug pin arranged in the split mode are provided with conical bosses for preventing the plug pin from withdrawing from the jack.

Furthermore, one of the matching parts of the pushing block and the spreading body is provided with an oblique sliding rail, and the other is provided with an oblique sliding groove matched with the oblique sliding rail, so that the spreading body is driven to be spread outwards in the front-back moving process of the pushing block.

Furthermore, the outer surface of the distraction body is provided with an inclined plane which gradually decreases from the front end to the rear end of the fusion cage main body, and the inclination angle of the inclined plane is 1-7 degrees.

Further, the front end of the fusion cage main body is in a bullet head shape;

and/or a pair of holding grooves is arranged on two sides of the rear end of the fusion cage main body;

and/or the outer surface of the distraction body is provided with convex teeth;

and/or the spreading body is provided with anti-retreat sharp teeth, the number of the anti-retreat sharp teeth is 4, and the anti-retreat sharp teeth are respectively positioned at four corners of the spreading body;

and/or an instrument operation part is arranged at the front end of the guide rod.

The utility model discloses following beneficial effect has:

the utility model discloses a distractable intervertebral fusion cage, the distraction structure of which comprises a push block which can move along the front and back directions of the fusion cage main body, a guide rod is arranged in front of the push block, a front guide hole is arranged on the front side wall of the fusion cage main body, and the guide rod is arranged in the front guide hole in a guide way, so that the push block can be conveniently guided in the front and back moving process, and the back and forth movement of the push block is more stable; be provided with between integration ware main part and the guide bar and be used for carrying out spacing limit structure to guide bar axial motion (be seesaw), on the one hand, can be convenient for carry on spacingly to the seesaw of guide bar, prevent that the guide bar from deviating from integration ware main part, get into the human body and cause unpredictable injury to the patient, on the other hand, can be convenient for carry on spacingly to the seesaw of ejector pad, and then carry on spacingly to the body of strutting's the height of strutting, the messenger struts stably.

Drawings

FIG. 1 is a schematic view of the three-dimensional structure of the distracting intervertebral cage of the present invention in a closed state;

FIG. 2 is a schematic sectional view of the distractable intervertebral cage of the present invention in a closed state;

fig. 3 is a schematic structural view of the distracting intervertebral cage of the present invention in a distracted state, wherein (a) is a perspective view, (b) is a side view, and (c) is a sectional view;

FIG. 4 is a schematic view of the distracting intervertebral cage of the present invention in an operating state;

fig. 5 is a schematic structural view of the main body of the distractor in the distractor, wherein (a) is a perspective view and (b) is a side view;

FIG. 6 is a schematic view of the push block of the distracting intervertebral fusion device of the present invention;

FIG. 7 is a schematic view of the distractor of the distracting intervertebral cage of the present invention;

fig. 8 is a schematic structural view of the driving rod of the distracting intervertebral fusion device of the present invention;

fig. 9 is a schematic structural view of the guide rod of the distracting intervertebral fusion device of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.

The utility model provides a can strut interbody fusion cage, as shown in fig. 1-9, including fusion cage main part 1 (frame type structure), the top and/or the below of fusion cage main part 1 are equipped with and strut body 2, are equipped with in the fusion cage main part 1 to be used for the drive to strut the body 2 and outwards open the structure of strutting, wherein:

strut structure including can follow fuse ware main part 1 preceding (the arrow in fig. 2 shows the direction) ejector pad 4 of rear direction removal, the place ahead of ejector pad 4 is equipped with guide bar 5, be equipped with preceding guiding hole 12 on the preceding lateral wall of fuse ware main part 1, guide bar 5 direction is installed in preceding guiding hole 12 (guide bar 5 sliding connection is in preceding guiding hole 12 promptly), it carries out spacing limit structure to guide bar 5 axial motion (the seesaw promptly) to be provided with between ware main part 1 and the guide bar 5.

When the distracting intervertebral fusion cage is used in an operation, the distracting intervertebral fusion cage (hereinafter referred to as the fusion cage) of the utility model is firstly in the state of not being distracted/closed as shown in figure 1, after the distracting intervertebral fusion cage is implanted into a human body (namely, after being placed into an intervertebral space), after the fusion cage is observed to be in a proper position in an intervertebral disc through image equipment, the push block 4 is driven to move along the front and back direction of the fusion cage main body 1, and the push block 4 drives the distracting body 2 to be outwards stretched (namely, the state shown in figure 3) in the process of moving back and forth; in this process, guide bar 5 slides in guiding hole 12, limit structure carries on spacingly to guide bar 5 motion, the effect of design like this is, on the one hand, in the ease of manufacturing installation, releasable connection between guide bar 5 generally and ejector pad 4, for example threaded connection, at this moment, in the reciprocating motion process, the easy not hard up guide bar 5 that leads to of being connected between guide bar 5 and the ejector pad 4 deviates from, get into human back aspect, can cause unpredictable injury to the patient, set up limit structure between integration ware main part and guide bar, can be under the condition of the normal direction that does not influence the guide bar, with guide bar and integration ware main part relatively fixed, avoid the guide bar to deviate from and get into in the human, improve the security of system usage, on the other hand, carry on spacingly to the guide bar, and then spacing the strut height of strut body 2, make and strut stably.

The utility model discloses a can strut interbody fusion cage, its strut structure includes the ejector pad that can move along the fusion cage main part fore-and-aft direction, and the place ahead of ejector pad is equipped with the guide bar, is equipped with the front guiding hole on the preceding lateral wall of fusion cage main part, and the guide bar direction is installed in the front guiding hole, is convenient for guide ejector pad in the back and forth movement process, makes the ejector pad back-and-forth movement more steady; be provided with between integration ware main part and the guide bar and be used for carrying out spacing limit structure to guide bar axial motion (be seesaw), on the one hand, can be convenient for carry on spacingly to the seesaw of guide bar, prevent that the guide bar from deviating from integration ware main part, on the other hand, can be convenient for carry on spacingly to the seesaw of ejector pad, and then spacing the body of strutting highly spacing, the messenger struts stably.

The limit structure between the fusion device body 1 and the guide rod 5 can adopt various structural forms which can be easily thought by those skilled in the art, for example, a radial protrusion is arranged on the guide rod, a closing structure is arranged at two ends of the front guide hole, the closing structure can be formed by strong pressure, and the limit between the radial protrusion on the guide rod and the closing structure at two ends of the front guide hole is realized by stop matching. However, for the convenience of implementation, the present invention preferably adopts the following structural form:

as shown in fig. 2 and 9, the limiting structure includes an annular groove 53 formed on the outer side (outer surface) of the guide rod 5 and extending in the axial direction of the guide rod 5, and a stop protrusion extending into the annular groove 53 is formed on the fusion device body 1 at a position corresponding to the annular groove 53.

According to the convex formation mode difference of stop, the utility model discloses can have following structural style:

the structure form I: as shown in fig. 2 and 5, a blind hole 13 (specifically, a punched hole) may be formed in a position of the fusion device body 1 corresponding to the annular groove 53, and the stop protrusion is formed by deforming the bottom wall of the stop protrusion toward the annular groove 53 after being punched by the blind hole 13; during assembly, after the guide rod 5, the push block 4 and the fusion device main body 1 are assembled, the blind hole 13 is punched, so that a protrusion is formed on the bottom wall of the blind hole, the protrusion extends into the annular groove 53 on the guide rod 5, namely, the protrusion is clamped in the annular groove 53 on the guide rod 5 to limit the front and back movement of the guide rod 5;

structural form two (not shown): the fusion device main body is provided with a pin hole communicated with the front guide hole, a fixing pin is inserted in the pin hole, and the stopping bulge extends into the annular groove from the tail end of the fixing pin to form; during assembly, after the guide rod, the push block and the fusion device main body are assembled, the fixing pin is inserted into the annular groove in the guide rod along the pin hole of the fusion device main body.

In order to facilitate disassembly and assembly, the guide rod 5 and the push block 4 are preferably detachably connected, specifically, a threaded hole 43 may be formed in the push block 4, and a stud 51 matched with the threaded hole 43 is formed on the guide rod 5, so that the guide rod 5 is detachably connected to the push block 4; during installation, the stud 51 on the guide rod 5 can be screwed along the threaded hole 43 on the push block 4. The front end of the guide bar 5 may be provided with an instrument operation portion 52 (specifically, may be a "straight" groove) to facilitate the operation of the guide bar 5.

As shown in fig. 3, the distraction structure may further include a driving rod 3, a rear mounting hole 11 is provided on the rear side wall of the fusion cage body 1, the rear portion of the driving rod 3 is located in the rear mounting hole 11, the front portion of the driving rod 3 is drivingly connected to a push block 4, and the push block 4 is drivingly connected to the distraction body 2 to drive the distraction body 2 to be spread outward in the front-rear movement process;

be equipped with vertical bone grafting cavity 41 on ejector pad 4, be equipped with in the actuating lever 3 along the extension of 3 length direction of actuating lever and with the bone grafting cavity 31 that 41 are linked together of bone grafting, the rear end of actuating lever 3 is equipped with and is linked together and supplies operation instrument male apparatus operation mouth 32 with bone grafting channel 31.

When the device is used in an operation, the driving rod 3 is driven by an operating instrument, the driving rod 3 drives the push block 4 to move along the front-back direction of the fusion device main body 1, and the push block 4 drives the spreading body 2 to spread outwards in the front-back moving process (namely the state shown in fig. 3); during the period, a doctor can observe the distractable intervertebral fusion device through the developing equipment, freely adjust the distraction height of the distraction body 2 by controlling the driving rod 3, and take out the instrument after confirming that the distraction height meets the requirements; finally, the operation instrument 6 is used for implanting bone filling materials such as bone mud, bone blocks, bone powder and the like into the bone grafting cavity 41 through the instrument operation opening 32 and the bone grafting passage 31.

The utility model discloses a can strut interbody fusion cage struts the back implanting the human body, still have bone grafting cavity 41 on the ejector pad 4, usable operating device 6 is through apparatus operation mouth 32 and bone grafting passageway 31 with bone mud, the bone piece, bone meal etc. bone filling material implants in bone grafting cavity 41, conveniently carry out the back bone grafting, make full use of the bone grafting space that increases after the fusion cage struts, at the inside abundant bone grafting of fusion cage, improve bone grafting and fuse the effect, the later stage bone fusion of being convenient for, thereby make the fusion cage fixity good, the bony fusion increases, satisfy clinical requirement. The utility model discloses a can strut interbody fusion cage easy operation is convenient, and it is convenient to plant the bone, and it is effectual to plant the bone, and the bone fusion rate is high. The utility model is mainly suitable for the spinal fusion fixation operation, in particular to the lumbar fusion fixation operation.

As shown in fig. 1-2, in order to increase the distance of distraction, the distractor 2 of the present invention preferably includes an upper distractor located above the fusion cage body 1 and a lower distractor located below the fusion cage body 1. It is contemplated that only the upper distractor or only the lower distractor may be provided if the distractable intervertebral cage requires only one-sided distraction.

In order to facilitate the driving rod 3 to drive the pushing block 4 to move along the front-back direction of the fusion cage body 1, various structural forms which can be easily thought by a person skilled in the art can be adopted, for example, the driving rod is connected in the rear mounting hole in a sliding manner, the front end of the driving rod is fixedly arranged on the pushing block, and the driving rod is provided with a clamping structure to realize self-locking after the position of the driving rod is moved in the rear mounting hole; however, for the distance of accurate regulation ejector pad 4 back-and-forth movement, the utility model discloses preferred following structural style that adopts:

as shown in fig. 3, 5-6 and 8, the rear mounting hole 11 is internally provided with an internal thread, the rear portion of the driving rod 3 is provided with a thread section 33 matched with the internal thread, and the front portion of the driving rod 3 is rotatably assembled (i.e., axially positioned and circumferentially rotatable) at the rear end of the push block 4 to drive the push block 4 to move along the front-rear direction of the fusion device body 1 during the rotation process. At this time, the driving rod 3 is driven to rotate so that the driving rod 3 moves back and forth in the rear mounting hole 11, thereby driving the pushing block 4 to move back and forth in the fusion cage body 1, and further driving the spreading body 2 to spread outwards. The rear end of the driving rod 3 may be provided with a quincunx hole which may be used as an instrument operation port 32 to facilitate the operation of the driving rod 3.

The rotary assembly between the front part of the driving rod 3 and the push block 4 can adopt various structural forms which can be easily conceived by those skilled in the art, for example, the rear end of the push block is provided with an insertion hole, the front end of the driving rod is inserted into the insertion hole, the front end of the driving rod is provided with an annular groove, the push block is provided with a pin hole communicated with the insertion hole, a fixed pin is arranged in the pin hole, and the tail end of the fixed pin extends into the annular groove so as to enable the driving rod to be rotatably assembled at the rear end of the push block; however, for the convenience of implementation and connection, the following structural forms are preferably adopted in the present invention:

as shown in fig. 6 and 8, one of the matching parts of the push block 4 and the driving rod 3 is provided with a jack 42, and the other is provided with a pin 34 matched with the jack 42 so that the driving rod 3 is rotatably assembled on the push block 4. In the embodiment shown in the figures, the pushing block 4 is provided with a jack 42, and the driving rod 3 is provided with a pin 34; when the push block is used, the pin 34 on the driving rod 3 is inserted into the insertion hole 42 of the push block 4.

Further, as shown in fig. 8, in order to better achieve the snap fit, a longitudinal slot 341 may be formed in the middle of the pin 34 to enable the pin 34 to be disposed in a split manner (to form a plurality of elastic pieces), and tapered bosses 342 for preventing the pin 34 from withdrawing from the insertion hole 42 are disposed on outer side surfaces of the split pin 34, that is, the sum of the lengths of the bottom edges of the tapered bosses 342 on the two halves is greater than the aperture of the insertion hole 42; during assembly, the pin 34 on the driving rod 3 is aligned with the insertion hole 42 on the push block 4 and the driving rod 3 is pressed, the pin 34 is elastically deformed under the action of the longitudinal slot 341 and smoothly enters the insertion hole 42, and after the pin 34 smoothly enters the insertion hole 42, the pin 34 is deformed and restored under the action of the longitudinal slot 341 to enable the tapered boss 342 on the pin 34 to be clamped in the insertion hole 42, so that the driving rod 3 and the push block 4 can rotate relatively and cannot fall off.

In order to drive the pushing block 4 to drive the spreading body 2 to spread outwards in the process of moving back and forth, the transmission connection between the pushing block 4 and the spreading body 2 can adopt various structural forms which can be easily thought by a person skilled in the art, such as an inclined plane pushing mode; however, for the convenience of guiding the distraction body 2 in the distraction process, the utility model discloses the preferred following structural style that adopts:

as shown in fig. 3 and fig. 6-7, one of the matching parts of the pushing block 4 and the spreading body 2 is provided with an oblique sliding rail 44 (specifically, the oblique sliding rail 44 extends vertically), and the other is provided with an oblique sliding slot 21 matched with the oblique sliding rail 44, so as to drive the spreading body 2 to spread outwards in the process of moving the pushing block 4 back and forth. In the embodiment shown in the figures, the push block 4 is provided with an oblique slide rail 44 which inclines towards the rear part of the push block 4, the spreading body 2 is provided with an oblique slide groove 21, and the push block 4 is driven to move forwards to spread the spreading body 2. The number of the inclined slide rails 44 is preferably two pairs and is respectively located outside two sides of the push block 4, and the number of the corresponding inclined slide grooves 21 is two pairs.

As shown in fig. 2, the outer surface of the distractor 2 may be provided with a slope 22 gradually decreasing from the front end to the rear end of the fusion cage body 1, and the slope 22 has an inclination angle of 1-7 degrees, so as to better conform to the physiological angle of the spine, and the distractor 2 can ideally restore the physiological lordosis and restore the physiological curvature of the spine after being distracted.

As shown in fig. 2 and 3, the front end of the cage body 1 is preferably bullet-shaped in order to facilitate the implantation of the distractible intervertebral cage. As shown in fig. 5, in order to facilitate the grip of the cage by the holder, a pair of grip grooves 14 may be formed at both sides of the rear end of the cage body 1.

As shown in fig. 7, in order to increase the bone fusion rate of the fusion cage, the distractor 2 may be provided with a bone grafting hole 23 communicating with the bone grafting cavity 41. In order to increase the firmness of the distractable intervertebral fusion device, the outer surface of the distracting body 2 can be provided with convex teeth 24, and the convex teeth 24 can also incline towards the rear end direction of the fusion device main body 1 so as to facilitate the implantation of the fusion device. In order to further increase the firmness of the distracting interbody fusion cage, the distracting body 2 can be provided with anti-retreat sharp teeth 25 (sheets), the number of the anti-retreat sharp teeth 25 is 4, and the anti-retreat sharp teeth 25 are respectively positioned at four corners of the distracting body 2, so that the distracting body 2 is more stably connected with the upper vertebral body and the lower vertebral body.

As shown in FIG. 7, to ensure the overall strength of the distractor body 2, the distractor body 2 preferably includes a solid outer frame region 26 and a porous structural region 27 within the solid outer frame region 26. The distraction body 2 is preferably manufactured by 3D printing or formed by processes such as acid washing, so that a porous structure is formed on the surface of the distraction body 2, and the distraction body is convenient to fuse with bones. The material of the spreader 2 is preferably titanium alloy or tantalum or niobium zirconium alloy, or a metallic/non-metallic absorbable material, etc.

The utility model discloses a can strut interbody fusion cage height and adjust wantonly, the afterbody has the bone grafting passageway, when implanting the intervertebral disc with the fusion cage in, the doctor can carry out height adjustment with the fusion cage through box spanner according to the intervertebral disc interior condition, can adjust the optimal position with the fusion cage, it is orthopedic to carry out the intervertebral, thereby it is good to make the fusion cage fixity, the fusibility is good, satisfy clinical requirement, reach the best effect, and bone grafting instrument accessible apparatus operation mouth and bone grafting passageway implant bone mud, the bone piece, bone meal and other bone filling material implant in the bone grafting cavity, strengthen the fusion effect of fusion cage. The utility model provides a prop open the body and print material and porous structure for 3D to this reinforcing fuses the fusion effect of ware. The utility model can perfectly recover the height and tension of the vertebral segment by utilizing the distraction force of the fusion device, realize the relief of compression, recover the physiological curvature of the spine, increase the bony fusion of the fusion device, ensure the stability of the spine,

the foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims (7)

1. The utility model provides a can strut interbody fusion cage which characterized in that, includes the fusion cage main part, the top and/or the below of fusion cage main part are equipped with the body that struts, be equipped with in the fusion cage main part and be used for the drive the outside open structure that struts of body, wherein:

the opening structure comprises a push block capable of moving along the front-back direction of the fusion cage main body, a guide rod is arranged in front of the push block, a front guide hole is formed in the front side wall of the fusion cage main body, the guide rod is installed in the front guide hole in a guiding mode, and a limiting structure used for limiting the axial movement of the guide rod is arranged between the fusion cage main body and the guide rod;

the limiting structure comprises an annular groove which is arranged on the outer side of the guide rod and extends along the axial direction of the guide rod, and a stop bulge extending into the annular groove is arranged on the fusion cage main body corresponding to the annular groove;

the distraction structure further comprises a driving rod, a rear mounting hole is formed in the rear side wall of the fusion cage main body, the rear part of the driving rod is located in the rear mounting hole, the front part of the driving rod is in driving connection with the push block, and the push block is in driving connection with the distraction body so as to drive the distraction body to be outwards spread in the front-rear movement process;

the push block is provided with a vertical bone grafting cavity, the driving rod is internally provided with a bone grafting channel which extends along the length direction of the driving rod and is communicated with the bone grafting cavity, and the rear end of the driving rod is provided with an instrument operation port which is communicated with the bone grafting channel and is used for inserting an operation instrument;

one of the matching parts of the pushing block and the spreading body is provided with an oblique sliding rail, and the other one of the pushing block and the spreading body is provided with an oblique sliding groove matched with the oblique sliding rail, so that the spreading body is driven to spread outwards in the front-back moving process of the pushing block.

2. The distractible intervertebral fusion cage of claim 1, wherein the cage body has a blind hole at a position corresponding to the annular groove, and the stop protrusion is formed by punching the blind hole and deforming a bottom wall thereof toward the annular groove;

or, a pin hole communicated with the front guide hole is formed in the fusion cage main body, a fixing pin is inserted into the pin hole, and the stopping protrusion extends into the annular groove from the tail end of the fixing pin to form the stopping protrusion;

or the guide rod is detachably connected with the push block.

3. The distractable intervertebral fusion device of claim 1, wherein the rear mounting hole has internal threads, the rear portion of the driving rod has thread segments matching the internal threads, and the front portion of the driving rod is rotatably mounted to the rear end of the push block to drive the push block to move in the forward and backward directions of the fusion device body during rotation.

4. A distractible intervertebral fusion device according to claim 3 wherein one of the engagement portions of the pushing block and the driving rod is provided with an insertion hole, and the other is provided with a pin engaged with the insertion hole so that the driving rod is rotatably assembled to the pushing block.

5. The distractable intervertebral fusion device of claim 4, wherein the prongs have a longitudinal slot in the middle to allow the prongs to be arranged in a split manner, and tapered bosses are provided on the outer side surfaces of the split prongs to prevent the prongs from being withdrawn from the insertion holes.

6. A distractible intervertebral fusion device according to claim 1 or 2 wherein the outer surface of the distracting body is provided with a ramp which decreases progressively from the front end to the rear end of the body, the ramp being inclined at an angle of 1 to 7 degrees.

7. The distractible intervertebral cage of claim 1 or 2, wherein the front end of the cage body is bullet-shaped;

and/or a pair of holding grooves is arranged on two sides of the rear end of the fusion cage main body;

and/or the outer surface of the distraction body is provided with convex teeth;

and/or the spreading body is provided with anti-retreat sharp teeth, the number of the anti-retreat sharp teeth is 4, and the anti-retreat sharp teeth are respectively positioned at four corners of the spreading body;

and/or the front end of the guide rod is provided with an instrument operation part.

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