Intervertebral fusion device

Abstract

The present invention relates to a prosthesis for implantation into an intervertebral space of a cervical vertebra, and specifically discloses an intervertebral fusion device, comprising: a fusion cage body having two end faces and a bone grafting window penetrating through the two end faces, the fusion cage body being implanted into the intervertebral space in such a manner that the two end faces thereof face end plates of two vertebrae, respectively; the bone plate is provided with through holes located in the upper portion and the lower portion respectively, the bone plate is arranged on the front side of the cervical vertebra and crosses two vertebrae defining an intervertebral gap, and the through hole in the upper portion and the through hole in the lower portion are opposite to the two vertebrae respectively; the bone screws penetrate through the through holes in the upper part and the lower part of the bone plate and are screwed into the vertebrae, so that the bone plate is respectively fixed with the two vertebrae; the linear component is provided with a near end and a far end, the near end of the linear component is attached to the middle of the bone plate, and the far end of the linear component extends into the intervertebral gap to be attached to the front side of the fusion cage body to limit displacement of the fusion cage body and maintain the fusion cage body in the middle area of the intervertebral gap.

Description

Technical Field

[0001] This invention relates to a prosthesis for implantation in the intervertebral space of the human cervical spine, and more particularly to an intervertebral fusion device. Background Technology

[0002] Anterior cervical discectomy and fusion (ACDF) is a surgical procedure in which the intervertebral disc is removed from the anterior cervical spine and a fusion device (or intervertebral implant) is inserted. After the fusion device is implanted, the endplate of the vertebra, after the surface cartilage has been scraped off, grows new bone in the direction of the opposite vertebra and combines with the fusion device to eventually fill the entire intervertebral space, thereby achieving fusion and fixation of the upper and lower vertebrae.

[0003] After the fusion cage is implanted into the intervertebral space, it is necessary to fix the two vertebrae above and below the fusion cage. The purpose of fixing the two vertebrae is twofold: firstly, to prevent the fusion cage from shifting or even dislodging from the intervertebral space in the early postoperative period before the two vertebrae fuse due to the enlargement of the intervertebral space; secondly, by fixing the two vertebrae and pressing them against the end face of the fusion cage with a certain pressure, the fusion cage can stimulate the endplate of the vertebrae, thereby promoting the growth of new bone towards the fusion cage in the area opposite to the fusion cage.

[0004] Based on the different methods of vertebral fixation, two types of interbody fusion devices are provided in the prior art.

[0005] The first type of interbody fusion device.

[0006] like Figure 1 As shown, the intervertebral fusion device 200 includes: a fusion body 201 and a bone screw 202, and a through hole extending obliquely from the front side of the fusion body 201 and penetrating the upper and lower end faces of the fusion body. During the surgery, the fusion device body 201 is implanted into the intervertebral space 1001, which has been retracted by a retractor and the endplate cartilage has been scraped away. Then, the bone screw 202 passes through a through hole on the front side of the fusion device body 201 and exits through the end face of the fusion device body 201. By turning the bone screw 202, its head is tilted and screwed into the vertebra 1000 through the endplate. By tightening the bone screw 202, the endplate of the vertebra 1000 is pressed against the end face of the fusion device body 201. In this way, the two vertebrae 1000 are fixed by the bone screws 202 that pass through the upper and lower end faces of the fusion device body 201 respectively and by means of the fusion device body 201 (this type of intervertebral fusion device has been disclosed in Chinese patents such as CN108852563A anterior cervical intervertebral fusion device with zero notch and CN118453212A an anti-regression trabecular zero notch intervertebral fusion device).

[0007] The second type of interbody fusion device.

[0008] like Figure 2 As shown, the vertebral fusion device 200' includes: a fusion body 201', a bone plate 203', and bone screws 202'; the upper and lower parts of the bone plate 203' are provided with through holes, and the bone screws 202' are used to pass through the through holes. During the operation, firstly, the fusion body 201' is inserted into the intervertebral space 1001, which has been retracted by a retractor and the endplate cartilage has been scraped away. Then, the bone plate 203' is placed on the anterior side of the vertebra 1000 and spans two vertebrae 1000 simultaneously. Thus, the upper and lower through holes of the bone plate 203' are opposite to the anterior surfaces of the upper and lower vertebrae, respectively. Then, the bone screws 202' are passed through the upper and lower through holes respectively, and the heads of the bone screws 202' are laterally screwed into the vertebra 1000 through the surface of the vertebra 1000 by turning the bone screws 202'.

[0009] The significant difference between the second type of interbody fusion device and the first type is that in the first type of interbody fusion device, the bone screws, the fusion device body, and the vertebrae are connected to each other, while in the second type of interbody fusion device, the fusion device body and the bone plate are separate, and the fusion device and the vertebrae are not connected.

[0010] The advantages and disadvantages of the two types of interbody fusion devices mentioned above will be introduced below.

[0011] Advantages and disadvantages of the first type of vertebral fusion device.

[0012] Advantages: The bone screws, the fusion device body, and the vertebra are connected to each other. Therefore, once the fusion device body is fixed during the operation, it will not shift after the operation. In addition, the entire device is located in the area where the intervertebral space is located and does not protrude from the anterior surface of the vertebra, thereby avoiding affecting anterior cervical tissues such as the esophagus and trachea. Therefore, this device is usually called a zero-notch intervertebral fusion device.

[0013] Disadvantages: During surgery, because the bone screw is inserted into the vertebrae at an angle through the endplate, the screw head may slip and shift during screw tightening, leading to undesirable displacement of the fusion cage. Also, the angle at which the bone screw is screwed into the vertebra may deviate from the predetermined angle, causing undesirable changes in the posture of the fusion cage. This results in different contact pressures on different areas of the end face of the fusion cage, or even only a localized area of ​​the end face contacting the endplate, for example... Figure 2As shown, only the front side of the end face contacts the end plate, and the rear side of the end face does not contact the end plate. The area of the end plate opposite the non-contact area of the end face of the fusion device body cannot be stimulated by the fusion device body, and thus, new bone growth in the surrounding area of this area is slow. Overcoming the above two defects requires the experience and skill of the doctor. In addition, because new bone grows from the end plate, the bone screw is screwed into the vertebra through the end plate, which destroys the bone tissue near the end plate, thereby affecting new bone growth. In addition, it is difficult to repair the operation after the bone screw is screwed.

[0014] Advantages and disadvantages of the second type of intervertebral fusion device.

[0015] Advantages: Because the bone screw is used to fix the bone plate and is separated from the fusion device body, the attitude of the fusion device body is less affected by the bone plate during the operation, and thus, the end face of the fusion device body is better attached to the vertebra. Because the bone screw is transversely screwed into the vertebra from the front side of the vertebra, the area being screwed into is far from the bone tissue near the end plate, and thus, it has less effect on new bone growth. In addition, because the bone screw is transversely screwed into the vertebra from the front side of the vertebra, the fixation operation on the vertebra is simple during the operation.

[0016] Disadvantages: 1. Because the fusion device body is not fixed to the vertebra during the operation, the fusion device body may be displaced after the initial stage of the operation before the two vertebrae are fused. If the fusion device body is displaced to the rear side, it may protrude from the rear side of the vertebra and compress the spinal cord, although the probability is small, but once the spinal cord is compressed, it may have serious consequences (such as high paraplegia).

[0017] 2. Because the bone plate is not an absolutely rigid component, and the bending stiffness of the bone plate in the sagittal plane is much smaller than that in the coronal plane, if the distance between the rear sides of the vertebrae increases and the distance between the front sides decreases due to the large amplitude of the patient's neck flexion motion during the initial stage after the operation, the fusion device body may be squeezed to move to the rear, thereby increasing the probability of the fusion device body protruding from the rear side of the vertebra.

[0018] 3. To reduce the probability of the fusion cage protruding posteriorly from the vertebra, during surgery, the fusion cage is usually positioned anterior to the intervertebral space, or even flush with the anterior side of the vertebra, to increase the distance between the posterior side of the fusion cage and the posterior side of the vertebra. This can reduce the probability of protrusion posteriorly from the vertebra and compressing the spinal cord to some extent. However, this leads to the following result: the amount of new bone on the anterior periphery of the fusion cage is much smaller than that on the posterior side and the left and right sides (the so-called periphery new bone refers to new bone that grows from the endplate without being directly stimulated by the end face of the fusion cage and is located outside the area corresponding to the end face of the fusion cage; the growth rate of this new bone lags behind the growth rate of new bone in the area corresponding to the end face of the fusion cage, e.g. If the growth rate of new bone in the area corresponding to the bone graft window lags behind, the fusion cage may not be located in the middle of the surrounding new bone. In some cases, the front side of the fusion cage may not be covered by surrounding new bone because it is flush with the front side of the vertebra. This state has a large difference in mechanical properties from the ideal state where the intervertebral space is completely filled with new bone (while if the fusion cage is located in the middle area, the difference from the ideal state where it is completely filled with new bone is not significant). This can lead to the following: if the bone plate needs to be removed after intervertebral fusion due to the impact on anterior cervical tissues such as the esophagus and trachea, the two fused vertebrae may have insufficient bending resistance in the sagittal plane to flexion-flexion movements (flexion-flexion movements include flexion-flexion movements and flexion-flexion movements) after the bone plate is removed.

[0019] 4. The bone plates have high tensile stiffness in the direction of their arrangement along the vertebrae. Therefore, in this direction, the bone plates can be considered rigid bodies. Postoperatively, because the bone plates cannot elongate, the growth of new bone can lead to excessive contact pressure between the endplate and the end face of the fusion cage. Excessive contact pressure can actually hinder new bone growth. Furthermore, for patients with osteoporosis, excessive contact pressure may even cause collapse of the bone tissue inside the vertebra. Although bone plates capable of elastic elongation have been developed in the present technology, configuring elastic elongation functionality results in complex bone plate structures and increased processing difficulty.

[0020] 5. The anterior surface of the vertebra is not an ideal smooth cylindrical surface and may be uneven, especially in middle-aged and elderly patients. In addition, the bone plate is relatively hard, and the large pre-tightening force between the bone plate and the anterior surface of the vertebra may damage the bone tissue in the local protruding areas of the anterior surface.

[0021] 6. During the surgery, because the patient is in a supine position, after the fusion device is implanted into the intervertebral space, it is necessary to use clamping tools to keep the two vertebrae in a compressed state while installing the bone plate. Because the operating space is occupied by the clamping tools, the installation of the bone plate becomes more difficult. Summary of the Invention

[0022] The present application provides an intervertebral fusion device to solve the above technical problems in the prior art.

[0023] To solve the above technical problems, the present application adopts the technical solution of: An intervertebral fusion device comprises: a fusion device body having two end faces each configured with a plurality of spikes and a bone graft window penetrating through the two end faces, the fusion device body being implanted into an intervertebral space with the two end faces respectively facing the end plates of two vertebrae; a bone plate having through holes respectively located at the upper and lower portions, the bone plate being arranged on the front side of the cervical vertebrae and straddling the two vertebrae defining the intervertebral space, the through holes of the upper and lower portions being respectively opposite to the two vertebrae; bone screws passing through the through holes of the upper and lower portions of the bone plate and being screwed into the vertebrae to fix the bone plate to the two vertebrae respectively; a linear member having a proximal end and a distal end, the proximal end of the linear member being attached to the middle portion of the bone plate, the distal end of the linear member extending into the intervertebral space and being attached to the front side of the fusion device body to limit the displacement of the fusion device body and maintain the fusion device body in the middle region of the intervertebral space.

[0024] Preferably, the distal end of the linear member is attached to the front side of the fusion device body in a manner allowing the fusion device body to be universally swung and locked after swinging.

[0025] Preferably, the linear member comprises: a tube body having a proximal end passing through the bone plate and being exposed to the front side of the bone plate and configured with a counterbore, the tube body having a distal end configured with an expandable portion surrounded by a plurality of expansion bodies; the front side of the fusion device body being configured with an entrance and a spherical cavity located at the rear side of the entrance, the expandable portion being used to extend into the spherical cavity through the entrance; a rod body passing through the tube hole of the tube body, the proximal end of the rod body being configured with a screw rod, the distal end of the rod body being configured with a tapered end, the expansion bodies being forced to expand into a spherical shape by driving the rod body to move forward and cooperating the tapered end with the expansion bodies of the expandable portion to perform expansion tightening on the spherical cavity to lock the fusion device body and the distal end of the tube body; a drive nut sleeved on the screw rod of the rod body and located in the counterbore of the proximal end of the tube body, so that a force applying tool can extend into the counterbore of the tube body from the front side of the bone plate to act on the drive screw rod to drive the rod body to move towards the front side by screwing the nut.

[0026] Preferably, the outer peripheral surface of the section of the tube body located in the intervertebral space is a frustoconical surface with a diameter at the distal end smaller than a diameter at the proximal end, and, after the elastic return of the inflatable body so that the inflatable portion is contracted, the radial dimension of the inflatable portion is smaller than the radial dimension of the inlet and smaller than the radial dimension of the distal end of the frustoconical surface of the tube body.

[0027] Preferably, a recessed groove is formed in the front side of the bone plate, a central hole penetrating the bone plate is formed in the groove bottom of the recessed groove, and the proximal end of the tube body passes through the central hole; An elastic connecting component is arranged in the recessed groove, the elastic connecting component has a flange ring and a sleeve body integrally formed with the flange ring, the flange ring is fixedly attached to the recessed groove, the proximal end of the tube body passes through the sleeve body, an opening is formed in the sleeve wall of the sleeve body to divide the sleeve wall into circumferentially arranged clamping walls, an external thread is arranged on the section where the opening is located, a locking nut is sleeved on the sleeve body, and the clamping walls are clamped or released by rotating the locking nut; wherein: A wave wall is arranged at the joint area of the flange ring and the sleeve body, and the wave wall is elastically deformed to allow the sleeve body to move.

[0028] Preferably, the bone plate comprises a main plate body and two auxiliary plate bodies matched with the main plate body, and the through holes of the upper and lower parts of the bone plate are arranged on the two auxiliary plate bodies, respectively; wherein: Each auxiliary plate body is elastically moved in the upward and downward directions relative to the main plate body.

[0029] Preferably, two insertion grooves are arranged on the main plate body, and the two insertion grooves vertically extend from the upper and lower end faces of the main plate body, respectively; the auxiliary plate body has an attachment plate portion and an insertion plate portion integrally formed with the attachment plate portion, the insertion plate portions of the two auxiliary plate bodies are inserted into the two insertion grooves from above and below the main plate body, respectively, and can move along the insertion grooves; wherein: A tongue portion is cut in the middle area of the insertion plate portion, the head portion of the tongue portion faces the attachment plate portion, and elastic strips connected to each other are obtained on the tongue portion by cutting to allow the tongue portion to be elastically deformed, and a positioning hole is formed in the head portion of the tongue portion; A pin hole is formed in the area of the main plate body opposite to the positioning hole, a pin shaft is arranged at the pin hole, and the pin shaft passes through the positioning hole, so that, when the auxiliary plate body moves away from the main plate body, the elastic strips are elastically deformed by the limiting of the head portion of the tongue portion by the pin shaft to allow the auxiliary plate body to be elastically moved.

[0030] Preferably, the positioning hole is arranged as an oblong hole with a dimension in the length direction of the tongue portion greater than a dimension in the width direction of the tongue plate; A threaded hole is formed in the end of the pin shaft, a radial hole is formed in the pin shaft and penetrates the threaded hole, the radial hole is directed towards the hole wall of the positioning hole in the direction of the insertion of the insertion plate, a top bead is arranged in the radial hole, a top pin with a conical head is screwed into the threaded hole, the conical head pushes the top bead to move radially outwards to push against the hole wall of the positioning hole by screwing the top pin.

[0031] Preferably, a spacing component is arranged at the inner end of the through hole, the spacing component has a sleeve-shaped body and a plurality of finger-shaped elastic strips integrally formed with the sleeve-shaped body and arranged circumferentially to form a trumpet-shaped outer shape; an insertion hole is formed in the inner end of the through hole, the sleeve-shaped body is inserted into the insertion hole, and the bone screw passes through the sleeve-shaped body; wherein: When the head of the bone screw is screwed into the vertebra and tightened, the finger-shaped elastic strips are deformed to fit and press against the front surface of the vertebra.

[0032] Preferably, the rear side of the spherical cavity of the cage body is provided with a avoiding groove for accommodating the conical end of the distal end of the rod of the linear component.

[0033] Preferably, the cage body is made of polyether ether ketone material; the cross section of the bone graft window of the cage body is rectangular; the size of the window of the bone graft window is larger than the size of the middle region of the bone graft window; and the pointed bodies are a plurality of rectangularly arranged quadrangular pyramids.

[0034] Preferably, the bone plate is made of titanium alloy material, the tube and the rod of the linear component are both made of titanium alloy material, and the tube is made of two different titanium alloy materials; the titanium alloy for making the bone plate and the rod includes Ti-6Al-4V; and the titanium alloy material for making the tube includes any one of Ti-6Al-4V, Ti-13Nb-13Zr and Ti-12Mo-6Zr-2Fe.

[0035] Compared with the prior art, the intervertebral fusion device disclosed by the application has the following beneficial effects: 1. In the application, the linear component is additionally arranged, and the two ends of the linear component are respectively attached to the bone plate and the cage body, so that the bone plate and the cage body are connected, the cage body displacement is limited in the early postoperative period before the two vertebrae are fused, and the cage body is prevented from protruding from the rear side of the vertebra to compress the spinal cord.

[0036] 2、Because the bone plate can restrict the fusion cage body from moving backward through the linear member, the fusion cage body is allowed to be arranged in the approximate middle region of the intervertebral space instead of the anterior region, so that the peripheral space for new bone growth around the fusion cage body is more uniform, and the fusion cage body is evenly covered by the peripheral new bone after the peripheral new bone eventually fills the peripheral space to achieve fusion.

[0037] 3、Because the linear member is an elongated member with a large length-diameter ratio, the volume proportion of the peripheral space for peripheral new bone growth occupied by the section of the linear member in the intervertebral space is very small, and the linear member almost does not affect the bone fusion of the peripheral space and the mechanical properties after fusion.

[0038] 4、After fusion of two vertebrae, if the bone plate needs to be removed due to discomfort caused by affecting the anterior neck tissue such as trachea and esophagus, and the linear member also needs to be removed, because the outer periphery of the section of the linear member in the intervertebral space is a conical cylindrical surface and the radial dimension of the reset expandable part is smaller than the radial dimension of the distal end of the conical cylindrical surface, the linear member can be easily removed from the fused peripheral bone, and only a small bone hole is left.

[0039] 5、Because the fusion cage body is attached to the distal end of the linear member in a universal swing manner, the swing center of the fusion cage body is located on the body of the fusion cage body, so that adjusting the attitude of the fusion cage body will not cause displacement of the fusion cage body, making the position adjustment and attitude adjustment almost independent of each other.

[0040] 6、In the ACDF procedure, the operation of switching the attachment state of the distal end of the linear member and the fusion cage body is performed on the outside of the bone plate, so that the operation process becomes simple; when the bone plate and the linear member need to be removed, all the removal operations are completed on the outside of the bone plate, so that the removal operation becomes simple.

[0041] 7、During the bone fusion after the ACDF procedure, new bone growth and fusion can cause relative attitude changes between the fusion cage body and the bone plate, by forming a semi-locked connection state between the fusion cage body and the distal end of the linear member and forming an elastic damping swing connection state between the linear member and the bone plate through the elastic connecting member, the linear member is allowed to produce slight swing to adapt to the relative attitude changes between the fusion cage body and the bone plate, so as to avoid the linear member pulling the fusion cage body to move and change attitude relative to the vertebrae due to the relative attitude changes between the fusion cage body and the bone plate.

[0042] 8、By configuring the bone plate to be able to elastically extend, the contact pressure between the end plate of the vertebra and the end surface of the fusion device body can be suppressed within a reasonable range to conform to new bone growth. Furthermore, the tongue plate having elastic properties is obtained from the bone plate by cutting, and the bone plate is configured to be able to elastically extend, which makes the structure of the bone plate simple and reduces the difficulty of manufacturing and assembly.

[0043] 9、By configuring the bone plate with a top nail, a top bead, and a long round hole and other related structures to apply a pre-tightening force to two vertebrae, the use of clamping tools to apply a pre-tightening force to two vertebrae is avoided, and the installation operation of the bone plate becomes simple.

[0044] 10、By providing a spacer member with a plurality of finger-shaped elastic strips in the corresponding area of the through hole, after the vertebrae are fixed with bone screws, the plurality of finger-shaped elastic strips disperse the contact force of the spacer member with the front surface of the vertebrae, avoiding stress concentration in this area. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 A state view of the intervertebral fusion device of the first type in the prior art after being implanted into the intervertebral space.

[0046] Figure 2 A state view of the intervertebral fusion device of the second type in the prior art after being implanted into the intervertebral space.

[0047] Figure 3 A perspective structural schematic view of the intervertebral fusion device provided by the embodiment of the present application.

[0048] Figure 4 A perspective sectional view of the intervertebral fusion device provided by the embodiment of the present application.

[0049] Figure 5 A perspective sectional view of the fusion device body provided by the embodiment of the present application.

[0050] Figure 6 A perspective structural schematic view of the linear member in the intervertebral fusion device provided by the embodiment of the present application.

[0051] Figure 7 A perspective structural schematic view of the main plate body in the bone plate provided by the embodiment of the present application.

[0052] Figure 8 A perspective structural schematic view of the auxiliary plate body in the bone plate provided by the embodiment of the present application.

[0053] Figure 9 A perspective structural schematic view of the spacer member provided by the embodiment of the present application.

[0054] Figure 10A lateral view of the intervertebral fusion device provided by the present application after the ACDF surgery is performed.

[0055] Figure 11 A front view of the intervertebral fusion device provided by the present application after the ACDF surgery is performed.

[0056] Figure 12 A lateral view of the intervertebral fusion device provided by the present application after the fusion of the two vertebrae is achieved.

[0057] Figure 13 A lateral view of the two vertebrae after the fusion is achieved after the bone plate and linear component are removed.

[0058] Reference signs: 100 - intervertebral fusion device; 10 - fusion body; 11 - bone graft window; 12 - end face; 121 - pointed body; 13 - inlet; 14 - spherical cavity; 15 - avoidance groove; 20 - bone plate; 21 - main plate body; 211 - insertion slot; 212 - pin hole; 213 - central hole; 214 - sink groove; 22 - auxiliary plate body; 221 - attachment plate part; 2211 - through hole; 222 - insertion plate part; 2221 - tongue part; 2222 - elastic strip; 2223 - positioning hole; 23 - pin shaft; 231 - threaded hole; 232 - radial hole; 233 - top bead; 234 - jam nut; 2341 - conical surface; 2342 - cylindrical section; 30 - linear component; 31 - tube body; 311 - expandable part; 3111 - expansion body; 3112 - annular groove; 312 - counterbore; 32 - rod body; 321 - conical end; 322 - screw rod; 33 - elastic connecting component; 331 - flange ring; 332 - sleeve body; 333 - wavy wall; 341 - drive nut; 342 - locking nut; 40 - bone screw; 50 - spacer component; 51 - finger-shaped elastic strip; 52 - sleeve main body.

[0059] 1000 - vertebra; 1001 - intervertebral space; 2000 - fresh bone; 3000 - peripheral new bone. DETAILED DESCRIPTION

[0060] As Figure 3 and shown in the drawings, Figure 10 Embodiments of the present application disclose an intervertebral fusion device 100 used in an anterior cervical discectomy and fusion (ACDF) procedure, which comprises three components, i.e., a fusion body 10 for implanting into an intervertebral space 1001 of two vertebrae 1000 of a cervical vertebra, a bone plate 20 for fixing the two vertebrae 1000 corresponding to the fusion body 10, and a linear component 30 with two ends respectively attached to the bone plate 20 and the fusion body 10.

[0061] In this invention, the linear component 30 should be understood as: the component extends substantially along a straight line, and under the definition that the direction of extension is called the length direction and other directions are called the radial direction, the component has a large length-to-diameter ratio. Therefore, in this invention, the linear component 30 can also be called an elongated component.

[0062] like Figure 3 and combined Figure 10 As shown, the surface of the fusion device body 10 has two opposite end faces 12. When the fusion device body 10 is implanted into the intervertebral space 1001 where the human intervertebral disc has been removed, the two end faces 12 of the fusion device body 10 face towards the endplates of the upper and lower vertebrae 1000 where the surface cartilage has been scraped off. Thus, in the early stage after ACDF surgery, the fusion device body 10 replaces the human intervertebral disc to maintain the intervertebral space 1001 and provides support. On the other hand, the fusion device body 10 forms contact pressure with the endplates of the vertebrae 1000 through the end faces 12, stimulating the endplates to grow new bone towards the opposite vertebrae 1000, thereby fusing the vertebrae 1000 with the fusion device body 10. Preferably, a pointed body 121 with a sharp point is machined on each end face 12 of the fusion body 10. Under contact pressure, the tip of the pointed body 121 is inserted into the surface of the endplate, thereby restricting the displacement of the fusion body 10 and stimulating the rapid growth of new bone. In this invention, the pointed body 121 with a matrix arrangement of quadrangular vertebral structures is obtained by machining triangular grooves arranged in sequence and crisscrossing on the end face 12.

[0063] The fusion device body 10 also has a bone graft window 11 extending through its two end faces 12. Before implanting the fusion device body 10 into the intervertebral space 1001, the bone graft window 11 is filled with bone tissue or bone growth inducing material to increase new bone density and induce new bone growth during bone fusion after ACDF surgery. The filled bone tissue can be allogeneic dry bone or allogeneic fresh bone shavings 2000 obtained during cartilage removal. In this invention, the bone graft window 11 is processed into a rectangular cross-section structure, and the size of the window of the bone graft window 11 is larger than the size of the central region of the bone graft window 11. During the ACDF postoperative period, the new bone growing from the endplates of the two vertebrae 1000 fuses with each other through the bone graft window 11.

[0064] The fusion device body 10 can be made of a biocompatible metallic material or a biocompatible non-metallic material, such as titanium alloy (e.g., Ti-6Al-4V) or polyether ether ketone (PEEK) non-metallic material. Preferably, the fusion device body 10 is made of polyether ether ketone.

[0065] like Figure 10 and Figure 11 and combinedFigure 3 As shown, the bone plate 20 is positioned on the anterior side of the cervical vertebrae and simultaneously spans two vertebrae 1000 corresponding to the fusion device body 10 for fixing the two vertebrae 1000 before bone fusion and for supporting the two vertebrae 1000 together with the fusion device body 10. Specifically, the bone plate 20 has two through holes 2211 located on its upper part and two through holes 2211 located on its lower part. The two through holes 2211 on the upper part are opposite to the anterior surface of the vertebrae 1000 above the fusion device body 10, and the two through holes 2211 on the lower part are opposite to the anterior surface of the vertebrae 1000 below the fusion device body 10. When the fusion device body 10 is implanted into the intervertebral space 1001 and the bone plate 20 needs to be installed, the bone screws 40 are inserted laterally through the two upper through holes 2211 and screwed into the upper vertebra 1000, and the bone screws 40 are inserted laterally through the two lower through holes 2211 and screwed into the lower vertebra 1000. Thus, the two vertebrae 1000 are fixed by means of the bone plate 20. Preferably, the distance between the two upper through holes 2211 and the distance between the two lower through holes 2211 are greater than the width of the middle region of the bone plate 20, thereby reducing the contact between the bone plate 20 and the anterior surface of the vertebra 1000 and increasing the stability of the bone screws 40.

[0066] Regardless of whether the bone plate 20 is a single structure or a split structure assembled from multiple plates (the structure will be described below), the main body of the bone plate 20 is made of a titanium alloy material with a high elastic modulus, specifically Ti-6Al-4V titanium alloy material, which gives the bone plate 20 excellent bending and torsional resistance.

[0067] like Figure 10 As shown, the linear component 30 has a proximal end and a distal end. The proximal end of the linear component 30 is used to attach to the middle region of the bone plate 20, and the distal end of the linear component 30 extends into the intervertebral space 1001 to attach to the anterior side of the fusion cage body 10 to limit displacement of the fusion cage body 10 and maintain the fusion cage body 10 in the middle region of the intervertebral space 1001. Thus, the fusion cage body 10 and the bone plate 20 are connected through the linear component 30.

[0068] The linear component 30 provided by the present invention, as well as the fusion body 10 and the bone plate 20 that cooperate with the linear component 30, have the following structures.

[0069] like Figure 4 , Figure 6 , Figure 10As shown, the linear component 30 comprises a tube body 31 and a rod body 32. The distal end of the tube body 31 is configured with an expandable portion 311 comprising a plurality of expansion bodies 3111 arranged in a circumferential direction, which are separated by V-shaped slits cut on an ellipsoidal body at the distal end of the tube body 31, the plurality of expansion bodies 3111 enclose an expandable hole which is in communication with the tube hole of the tube body 31, and annular grooves 3112 are processed at the regions where the roots of the expansion bodies 3111 are located by removing materials, so that the roots of the expansion bodies 3111 form weak portions, and thus the elastic deformation of the expansion bodies 3111 occurs at the roots of the expansion bodies 3111. The rod body 32 is inserted into the tube body 31 and can move axially along the tube body 31, the distal end of the rod body 32 is configured with a tapered end head 321, and the proximal end of the rod body 32 is processed with a screw rod 322 with a certain length. When assembling the linear component 30, the proximal end of the rod body 32 is inserted into the tube body 31 from the distal end of the tube body 31, and the rotation of the rod body 32 relative to the tube body 31 is limited by means such as keying, and the screw rod 322 of the rod body 32 finally reaches the proximal end of the tube body 31, and the tapered end head 321 of the rod body 32 reaches the expandable portion 311 at the distal end of the tube body 31, before an axial force towards the proximal end (or front side) is applied to the rod body 32, a part of the tapered end head 321 of the rod body 32 protrudes from the end of the expandable portion 311, all the expansion bodies 3111 are in a reset state, and the expandable portion 311 is in a contracted state, when the axial force towards the proximal end is applied to the rod body 32, the rod body 32 as a whole moves towards the proximal end, and the distal tapered end head 321 enters the expandable portion 311 to force the expandable portion 311 to expand into a spherical shape by cooperation of the tapered end head 321 and the expansion bodies 3111. A counterbore 312 with a larger diameter than the tube hole of the tube body 31 is processed at the proximal end of the tube body 31, the screw rod 322 of the rod body 32 extends into the counterbore 312 without protruding from the end face of the distal end of the tube body 31, a drive nut 341 is sleeved on the screw rod 322, and a reserved gap is provided between the drive nut 341 and the hole wall of the counterbore 312 to allow the corresponding force applying tool to extend into the counterbore 312 to screw the drive nut 341, by screwing the drive nut 341, the drive nut 341 forces the expandable portion 311 to expand by abutting against the hole bottom of the counterbore 312 and by forming a screw transmission with the screw rod 322 to drive the rod body 32 as a whole to move towards the proximal end, and by unscrewing the drive nut 341 in reverse and relying on the elastic reset of the expansion bodies 3111, the expandable portion 311 is contracted.

[0070] As Figure 4 and Figure 5As shown, the entrance 13, the spherical cavity 14 through which the entrance 13 penetrates, and the avoidance slot 15 through which the spherical cavity 14 penetrates are sequentially machined from the front side to the rear side of the fusion cage body 10, so that the minimum diameter of the entrance 13 is smaller than the diameter of the spherical cavity 14. When the distal end of the linear member 30 is attached to the fusion cage body 10, the inflatable portion 311 is reset to the contracted state by reversely screwing the drive nut 341, so that the inflatable portion 311 in the contracted state enters the spherical cavity 14 through the entrance 13 of the fusion cage body 10, and the tapered end head 321 of the rod body 32 protruding from the inflatable portion 311 is just located in the avoidance slot 15 so that the inflatable portion 311 can enter the spherical cavity 14. By forwardly screwing the drive nut 341, the inflatable portion 311 can be inflated to a diameter greater than the diameter of the entrance 13, so that the inflatable portion 311 is limited to be taken out of the spherical cavity 14, the distal end of the linear member 30 is attached to the front side of the fusion cage body 10, and the fusion cage body 10 is allowed to freely universal swing within a certain angle range relative to the linear member 30. By continuously forwardly screwing the drive nut 341, the inflatable portion 311 is further inflated to generate a certain contact force with the spherical cavity 14, the friction force generated by the contact force allows the fusion cage body 10 to universal swing with a certain damping, and by screwing the drive nut 341, the inflatable portion 311 is in close contact with the spherical cavity 14 to lock the fusion cage body 10 to completely fix the fusion cage body 10 to the distal end of the linear member 30.

[0071] As Figure 4As shown, a groove 214 is formed on the outer side of the middle part of the bone plate 20. A central hole 213 is formed at the bottom of the groove 214. The diameter of the central hole 213 is larger than the outer diameter of the proximal end of the tube body 31 of the linear component 30. An elastic connecting component 33 is arranged in the groove 214. The elastic connecting component 33 includes an integrally formed flange ring 331 and a sleeve 332. The flange ring 331 is attached and fixed to the bottom of the groove 214 by means such as fastening, welding, or heat bonding. The sleeve 332 is coaxial with the central hole 213. External threads are machined on the sleeve wall of the sleeve 332. Multiple circumferentially arranged V-shaped notches are machined on the sleeve wall to form multiple circumferentially arranged clamping walls. A locking nut 342 is fitted in the area where the clamping wall is located. The locking nut 342 is configured with a tapered thread hole 231. Thus, the clamping wall can be radially contracted by turning the locking nut 342. The junction area between the flange ring 331 and the sleeve 332 is processed with a corrugated wall 333 by stamping, thermoforming, etc. This corrugated wall 333 allows the sleeve 332 to swing when subjected to a certain bending moment. Therefore, the elastic connector allows the sleeve 332 to swing in a way that provides elastic damping. The distal end of the tube 31 of the linear component 30 passes through the sleeve 332. Thus, by tightening the locking nut 342, the elastic wall is released, allowing the tube 31 to move. By tightening the locking nut 342 in the opposite direction, the elastic wall clamps the tube 31 to restrict its movement. This allows the position of the fusion device body 10 in the intervertebral space 1001 to be adjusted. Furthermore, the bone plate 20 allows the linear component 30 to swing slightly while providing a certain degree of support through the elastic connector 33.

[0072] The tube body 31 and rod body 32 of the linear component 30 are preferably made of a biocompatible titanium alloy. More preferably, the rod body 32 is made of a Ti-6Al-4V titanium alloy with a high elastic modulus; the tube body 31 is made of a Ti-6Al-4V titanium alloy with a high elastic modulus and a Ti-13Nb-13Zr titanium alloy or a Ti-12Mo-6Zr-2Fe titanium alloy with strong elastic deformation capacity and relatively low elastic modulus. Specifically, the main body section, including the proximal section, is made of Ti-6Al-4V titanium alloy, and the proximal section, including the expandable part 311, is made of Ti-13Nb-13Zr titanium alloy or Ti-12Mo-6Zr-2Fe titanium alloy. The main body section and the proximal section can be fixedly attached by welding, anchoring, or threaded connection. By selecting Ti-13Nb-13Zr titanium alloy or Ti-12Mo-6Zr-2Fe titanium alloy, the expandable part 311 has excellent elastic deformation capacity. The elastic connecting component 33 is preferably made of Ti-12Mo-6Zr-2Fe titanium alloy, so that the corrugated plate of the elastic connecting component 33 has excellent elastic deformation capability.

[0073] like Figure 4 and Figure 6As shown, in some preferred structures of the linear member 30, the outer peripheral surface of the tubular body 31 at the section located in the intervertebral space 1001 is a conical surface with a diameter at the distal end smaller than that at the proximal end, and, after the elastic reset of the inflatable body 3111 so that the inflatable section 311 is contracted, the radial dimension of the inflatable section 311 is smaller than the radial dimension of the inlet 13 and the radial dimension of the distal end of the conical surface of the tubular body 31.

[0074] The following describes the process of performing ACDF surgery with the above-described intervertebral fusion device 100.

[0075] First, the head of the patient is tilted backward, an incision is made at the corresponding part of the neck, and the anterior cervical tissues such as trachea and esophagus are spread apart to expose the human intervertebral disc to be replaced and the upper and lower vertebrae 1000 corresponding to the human intervertebral disc; then, the two vertebrae 1000 are pulled apart with a retractor to increase the distance between the two vertebrae 1000, the human intervertebral disc is removed with a cutter, and the cartilage on the surface of the endplate of the two vertebrae 1000 is scraped off with a scraper. Then, the fusion device body 10 is inserted into the middle region of the intervertebral space 1001 to perform a trial fitting so as to select a fusion device body 10 with a proper size.

[0076] Then, the inflatable section 311 at the distal end of the linear member 30 is inserted into the spherical cavity 14 at the front side of the fusion device body 10, the driving nut 341 at the proximal end is screwed to inflate the inflatable section 311, thereby achieving a locked or semi-locked state between the fusion device body 10 and the distal end of the linear member 30, the fusion device body 10 is delivered to the middle region of the intervertebral space 1001 through the linear member 30 by attaching a delivery tool to the proximal end of the linear member 30, and the position of the fusion device body 10 is fine-tuned to adjust the fusion device body 10 to a proper position.

[0077] Then, the retractor is removed to allow the two vertebrae 1000 to naturally press against the two end faces 12 of the fusion device body 10, and then the driving nut 341 is unscrewed in the opposite direction to slightly contract the inflatable section 311, thereby allowing the linear member 30 to swing omnidirectionally relative to the fusion device body 10, and thus allowing the spatial position of the proximal end of the linear member 30 to be adjusted.

[0078] Then, the bone plate 20 is attached to the front side of the cervical vertebrae while straddling the upper and lower two vertebrae 1000 corresponding to the fusion device body 10, and the bone plate 20 is adjusted to a proper position (the proper position specifically refers to a position that can accommodate the bone screws 40, can avoid affecting the anterior cervical tissues as much as possible, can avoid concentrated contact force with the front surface of the vertebrae 1000 as much as possible, etc.), and then the bone screws 40 are screwed into the vertebrae 1000 through the through holes 2211 of the bone plate 20, and the distal end of the tubular body 31 after the spatial position adjustment is passed through the central hole 213 of the bone plate 20 and the sleeve 332 of the elastic connecting member 33.

[0079] Then, before the locking nut 342 is kept in the loosened state, the bone screw 40 is screwed into the upper and lower vertebrae 1000 through the through hole 2211, and since the distal end and the proximal end of the linear member 30 are not locked, the slight movement of the position of the bone plate 20 caused by the screwing of the bone screw 40 hardly pulls the fusion cage body 10 to cause the undesired displacement and attitude change, and the bone plate 20 is fixed with the two vertebrae 1000 by screwing the bone screw 40.

[0080] As shown in Figure 10 and Figure 11 , first, the proximal end of the linear member 30 is fixedly connected with the sleeve body 332 of the elastic connecting member 33 by screwing the locking nut 342 from the outside of the bone plate 20 by using the corresponding force applying tool, and then the expandable part 311 is expanded by screwing the driving nut 341 by using the corresponding force applying tool, so that the fusion cage body 10 and the linear member 30 form a semi-locked state, so that the fusion cage body 10 needs to overcome a certain damping to swing relatively.

[0081] Finally, the anterior cervical tissue is reset and the incision is sutured.

[0082] The advantages of the above-mentioned intervertebral fusion device 100 in the ACDF operation and after the ACDF operation are introduced as follows: 1. In the present application, the linear member 30 is additionally arranged and the two ends of the linear member 30 are respectively attached to the bone plate 20 and the fusion cage body 10, so that the bone plate 20 and the fusion cage body 10 are connected, so that the displacement of the fusion cage body 10 can be limited in the early postoperative period before the two vertebrae 1000 are fused, and the fusion cage body 10 is prevented from protruding to the posterior side of the vertebrae 1000 to compress the spinal cord.

[0083] 2. Since the bone plate 20 can limit the posterior displacement of the fusion cage body 10 through the linear member 30, the fusion cage body 10 can be arranged in the approximate middle region of the intervertebral space 1001 instead of the anterior region, so that the peripheral space for the growth of new bone around the fusion cage body 10 is relatively uniform, as shown in Figure 12 , and further, after the peripheral new bone 3000 finally fills the peripheral space to achieve fusion, the fusion cage body 10 is uniformly covered by the peripheral new bone 3000.

[0084] 3. Since the linear member 30 is an elongated member with a large length-diameter ratio, as shown in Figure 12 and Figure 13 , the volume proportion of the peripheral space for the growth of the peripheral new bone 3000 occupied by the section of the linear member 30 in the intervertebral space 1001 is very small, so that the linear member 30 hardly affects the bone fusion of the peripheral space and the mechanical properties after fusion.

[0085] 4、After the fusion of two vertebrae 1000, if the bone plate 20 needs to be removed due to the discomfort caused by the bone plate 20 affecting the anterior tissue of the neck such as the trachea, esophagus, etc. and the linear member 30 also needs to be removed, first, the bone screw 40 is unscrewed, then the locking nut 342 is loosened so that the proximal end of the tube body 31 of the linear member 30 can be pulled out of the sleeve body 332 of the elastic connecting member 33 and the central hole 213 of the bone plate 20, so that the bone plate 20 can be removed, then the driving nut 341 is screwed by the corresponding force tool to make the inflatable part 311 at the distal end of the linear member 30 shrink to the minimum, because the outer periphery of the section of the intervertebral space 1001 is a conical surface and the radial size of the inflatable part 311 after shrinking is smaller than the radial size of the distal end of the conical surface, so that the linear member 30 can be easily pulled out of the fused peripheral bone, as shown in Figure 3 , and only a small bone hole is left.

[0086] 5、Since the fusion body 10 is attached to the distal end of the linear member 30 in a universal swing manner, the swing center of the fusion body 10 is located on the entity of the fusion body 10 (specifically, the front side of the fusion body 10), so that adjusting the attitude of the fusion body 10 will not cause the fusion body 10 to displace, making the position adjustment and attitude adjustment almost independent of each other. However, if the swing center of the fusion body 10 is arranged at the connection between the bone plate 20 and the proximal end of the linear member 30, adjusting the attitude of the fusion body 10 may cause the fusion body 10 to change position greatly.

[0087] 6、In the ACDF procedure, the operation of switching the attachment state of the distal end of the linear member 30 and the fusion body 10 is performed on the outside of the bone plate 20, so that the operation process becomes simple; when it is required to remove the bone plate 20 and the linear member 30, all the removal operations are completed on the outside of the bone plate 20, so that the removal operation becomes simple.

[0088] 7、During the bone fusion after the ACDF procedure, new bone growth and fusion can cause relative position and attitude changes between the fusion body 10 and the bone plate 20. By making the fusion body 10 and the distal end of the linear member 30 form a semi-locking connection state and making the linear member 30 and the bone plate 20 form a connection state that swings under elastic damping through the elastic connecting member 33, the linear member 30 is allowed to swing slightly to adapt to the relative position and attitude changes between the fusion body 10 and the bone plate 20, so as to avoid the linear member 30 pulling the fusion body 10 to displace and change attitude relative to the vertebrae 1000 due to the relative position and attitude changes between the fusion body 10 and the bone plate 20.

[0089] The present application is directed to simplifying the operation and improving the fusion effect in ACDF by adding the linear component 30, and to simplifying the operation and improving the fusion effect in ACDF by improving the bone plate 20.

[0090] As shown in Figure 7 , Figure 8 , Figure 10 and in combination with Figure 4 , the improved bone plate 20 comprises a main plate body 21 and two auxiliary plate bodies 22. The central hole 213 for the proximal end of the pipe body 31 of the linear component 30 is arranged in the middle region of the main plate body 21. Two insertion slots 211 are arranged in the main plate body 21, which are arranged vertically from the upper and lower end faces of the main plate body 21, and preferably, arc-shaped slot walls are arranged on both sides of the insertion slots 211 in the width direction. Each auxiliary plate body 22 has an attachment plate part 221 and an insertion plate part 222 integrally formed with the attachment plate part 221, the width of the attachment plate part 221 is greater than the width of the insertion plate part 222, and the insertion plate parts 222 of the two auxiliary plate bodies 22 are respectively inserted into the insertion slots 211 from the upper end and the lower end of the main plate body 21 and can move vertically relative to the main plate body 21 along the insertion slots 211, and preferably, arc-shaped edges are arranged on both sides of the insertion plate part 222 in the width direction to slide with the arc-shaped slot walls of the insertion slots 211. The two through holes 2211 in the upper part and the two through holes 2211 in the lower part of the bone plate 20 are respectively arranged on the attachment plate part 221 of the two auxiliary plate bodies 22, so that the attachment plate part 221 of the two auxiliary plate bodies 22 respectively corresponds to the two vertebrae 1000 and is fixed with the two vertebrae 1000 by bone screws 40. Preferably, the width of the attachment plate part 221 of the auxiliary plate body 22 is greater than the width of the main plate body 21.

[0091] In the present application, as shown in Figure 8 , a slightly sunken rectangular region is machined on the two plate surfaces in the middle of the attachment plate part 221 of the auxiliary plate body 22 by removing material such as milling, and then the rectangular region is cut, and the trajectory of the cutting seam forms a U shape, so that a rectangular tongue part 2221 is directly obtained from the middle plate body of the insertion plate part 222, the side of the tongue part 2221 close to the attachment plate part 221 is separated from the insertion plate part 222 by the cutting seam to form a head part, and the root of the tongue part 2221 is connected with the main body of the insertion plate part 222 and is located on the side away from the attachment plate part 221; then, the tongue part 2221 is cut to obtain a plurality of elastic strips 2222 connected with each other in the insertion direction, which enables the tongue plate to elastically stretch in the vertical direction.

[0092] As shown in Figure 4 and Figure 8As shown, a positioning hole 2223 is formed in the head of the tongue 2221, and a pin hole 212 is formed in the main plate body 21 and penetrates the slot 211. After the insertion of the insertion plate part 222 of the secondary plate body 22 into the slot 211, the pin hole 212 is opposite to the positioning hole 2223. A pin shaft 23 is arranged in the pin hole 212 and passes through the positioning hole 2223 of the tongue 2221 of the secondary plate body 22. In this way, when a pulling force is applied to the two secondary bone plates 20 in the vertical direction, the elastic strips 2222 of the tongue 2221 are elastically deformed and the tongue plate is elastically compressed, so that the bone plate 20 formed by the assembly of the main plate body 21 and the two secondary plate bodies 22 has the ability of elastic elongation (micro-elongation) in the vertical direction. The purpose of configuring the bone plate 20 in this way is that during the fusion of the two vertebrae 1000, at the initial stage of fusion, the contact pressure between the end face 12 of the fusion cage body 10 and the end plate of the vertebra 1000 is conducive to stimulating the end plate to promote new bone growth. However, as the new bone grows, if the bone plate 20 is a rigid body, the contact pressure between the end face 12 and the end plate will increase significantly. Excessive contact pressure will affect the growth of new bone and may cause the collapse of loose bone tissue. If the bone plate 20 has a certain elastic elongation ability in the vertical direction while having sufficient rigidity, the contact pressure can be suppressed within a reasonable range to adapt to the growth of new bone.

[0093] The improved bone plate 20 provided by the present application has the advantages that the tongue plate with elastic properties is obtained from the bone plate 20 by cutting, and the bone plate 20 is configured to have the ability of elastic elongation, which makes the structure of the bone plate 20 simple and the manufacturing and assembly difficulty small.

[0094] In some preferred structures of the bone plate 20, such as Figure 4 and Figure 8As shown, the positioning hole 2223 is configured as an oblong hole with a dimension in the length direction of the tongue 2221 greater than a dimension in the width direction of the tongue plate; the pin shaft 23 is limited from rotating relative to the pin hole 212 by means such as a key fit; a threaded hole 231 is formed at the end of the pin shaft 23, a radial hole 232 is formed through the pin shaft 23 and faces the hole wall of the positioning hole 2223 in the insertion direction of the insertion plate portion 222, a top bead 233 is arranged in the radial hole 232, a jam nut 234 with a head having a tapered surface 2341 is screwed into the threaded hole 231, and the tapered surface 2341 is pushed against the top bead 233 to move the top bead 233 radially outward to push against the hole wall of the positioning hole 2223 by screwing the jam nut 234. Preferably, the external thread of the jam nut 234 and the threaded hole 231 of the pin shaft 23 are configured as an interlocking structure to prevent the jam nut 234 from unscrewing automatically. Preferably, a cylindrical surface section 2342 is configured between the tapered surface section 2341 and the external thread section of the jam nut 234, and after the top bead 233 is moved outward, the cylindrical surface section 2342 of the jam nut 234 contacts the top bead 233 instead of the tapered surface 2341 contacting the top bead 233, thereby preventing the top bead 233 from exerting an outward axial force on the jam nut 234.

[0095] The configuration of the above-mentioned jam nut 234, top bead 233, oblong hole and other related structures has the following advantages: In the ACDF procedure, in order to generate sufficient initial contact pressure between the end plates of the two vertebrae 1000 and the end face 12 of the fusion device body 10, when the two vertebrae 1000 are fixed using a conventional bone plate, a clamping tool (or a pressing workpiece) is used to apply a certain pre-tightening pressure to the two vertebrae 1000, so that after the bone plate is installed, sufficient contact pressure can be obtained between the end plates of the vertebrae 1000 and the end face 12 of the fusion device body 10. However, disadvantageously, on the one hand, the clamping tool needs to be configured with a target point on the vertebrae 1000 to apply the pre-tightening force, and on the other hand, the clamping tool may interfere with the screwing tool when screwing the bone screw 40, thereby increasing the operation difficulty.

[0096] However, when the vertebrae 1000 is fixed using the bone plate 20 provided by the present application, there is no need to use a clamping tool to provide pre-tightening force to the two vertebrae 1000, so there is no need to configure a target point and the bone plate 20 will not be interfered with when screwing the bone screw 40. After the bone plate 20 is installed, the top bead 233 is moved outward by screwing the jam nut 234 on the bone plate 20, and the movement of the top bead 233 will cause the tongue 2221 to be compressed in real time by pushing against the hole wall of the positioning hole 2223, thereby causing the sub-plate body 22 to move or have a tendency to move towards the main plate body 21 through the tongue 2221, and thereby increasing the contact pressure between the end plates of the vertebrae 1000 and the end face 12 of the fusion device body 10, so as to obtain sufficient initial contact pressure.

[0097] In some preferred structures of the bone plate 20, such asFigure 9 and Figure 10 As shown in FIG. 6, a spacer 50 is arranged at the inner end of each through hole 2211 of the bone plate 20, the spacer 50 has a sleeve-shaped body 52 and a plurality of finger-shaped elastic strips 51 which are integrally formed with the sleeve-shaped body 52 and arranged circumferentially to form a horn-shaped appearance; the inner end of the through hole 2211 is provided with a socket, so that the sleeve-shaped body 52 is inserted into the socket and the horn-shaped appearance of the plurality of finger-shaped elastic strips 51 is located on the inner side of the bone plate 20. The spacer 50 has the following functions: on the one hand, the plurality of finger-shaped elastic strips 51 separate the bone plate 20 from the vertebra 1000, so that only the spacer 50 contacts the front surface of the vertebra 1000, and the bone plate 20 does not contact the front surface of the vertebra 1000, thereby avoiding stress concentration between the bone plate 20 and the front surface of the vertebra 1000, and the spacer 50 plays the role of a common spacer; on the other hand, if the area of the front surface of the vertebra 1000 corresponding to the spacer 50 is uneven, each finger-shaped elastic strip 51 will produce its own elastic deformation to adapt to the uneven surface, thereby dispersing the contact force between the spacer 50 and the front surface of the vertebra 1000 and avoiding stress concentration in this area, so that stress concentration in the area where the bone screw 40 is arranged can be avoided. Preferably, the spacer 50 is made of Ti-13Nb-13Zr titanium alloy. The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application, the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements should also be considered to fall within the protection scope of the present application.

Claims

1. An intervertebral fusion device, comprising: The intervertebral fusion device comprises: a fusion cage body having two end faces each provided with a plurality of spikes and a bone graft window penetrating through the two end faces, the fusion cage body being implanted into an intervertebral space with the two end faces respectively facing the end plates of two vertebrae; a bone plate having a through hole in each of the upper and lower portions, the bone plate being arranged on the anterior side of the cervical vertebrae and straddling the two vertebrae defining the intervertebral space, the through holes in the upper and lower portions being respectively opposite to the two vertebrae; bone screws passing through the through holes in the upper and lower portions of the bone plate and being screwed into the vertebrae to fix the bone plate to the two vertebrae respectively; a linear member having a proximal end and a distal end, the proximal end of the linear member being attached to the middle portion of the bone plate, the distal end of the linear member extending into the intervertebral space and being attached to the anterior side of the fusion cage body to limit the displacement of the fusion cage body and maintain the fusion cage body in the middle region of the intervertebral space.

2. The intervertebral fusion device of claim 1 wherein, The distal end of the linear member is attached to the anterior side of the fusion cage body in a manner allowing the fusion cage body to be swiveled and locked after swiveling.

3. The intervertebral fusion device of claim 2, wherein the first and second endplates are substantially planar. The linear member comprises: a tubular body having a proximal end passing through the bone plate and being exposed to the anterior side of the bone plate and being provided with a counterbore, the tubular body having a distal end provided with an expandable portion surrounded by a plurality of expansion bodies, the anterior side of the fusion cage body being provided with an entrance and a spherical cavity behind the entrance, the expandable portion being used to extend into the spherical cavity through the entrance; a rod body passing through the tubular hole of the tubular body, the rod body having a proximal end provided with a screw rod and a distal end provided with a conical end head, the expansion bodies being forced to expand into a spherical shape by driving the rod body to move forward and cooperating with the conical end head and the expansion bodies of the expandable portion to tighten the spherical cavity to lock the fusion cage body and the distal end of the tubular body; a drive nut being sleeved on the screw rod of the rod body and being located in the counterbore of the proximal end of the tubular body, so that a force applying tool can extend into the counterbore of the tubular body from the anterior side of the bone plate to act on the drive screw rod to drive the rod body to move towards the anterior side by screwing the nut.

4. The intervertebral fusion device of claim 3, wherein the first and second endplates are substantially planar. The outer peripheral surface of the section of the tubular body in the intervertebral space is a conical cylindrical surface with a smaller diameter on the distal end side than on the proximal end side, and after the elastic reset of the expansion bodies causes the expandable portion to contract, the radial dimension of the expandable portion is smaller than the radial dimension of the entrance and the radial dimension of the distal end of the conical cylindrical surface of the tubular body.

5. The intervertebral fusion device according to claim 3, wherein: a recess is formed in the anterior side of the bone plate, a central hole penetrating through the bone plate is formed in the bottom of the recess, and the proximal end of the tubular body passes through the central hole; an elastic connecting member is arranged in the recess, the elastic connecting member has a flange ring and a sleeve body integrally formed with the flange ring, the flange ring is fixedly attached to the recess, the proximal end of the tubular body passes through the sleeve body, a gap is formed in the sleeve wall of the sleeve body to separate the sleeve wall into circumferentially arranged clamping walls, an external thread is formed in the section where the gap is located, and a locking nut is sleeved on the sleeve body, the clamping walls are clamped or released by screwing the locking nut; wherein: The intersection area of the flange ring and the sleeve body is configured with a wavy wall which is elastically deformed to allow the sleeve body to move.

6. The spinal fusion device according to claim 1, wherein, The bone plate comprises a main plate body and two auxiliary plate bodies matched with the main plate body, and the through holes of the upper and lower parts of the bone plate are arranged on the two auxiliary plate bodies respectively; wherein: Each auxiliary plate body is elastically moved in the up and down directions relative to the main plate body.

7. The spinal fusion device of claim 6, wherein the at least one projection is configured to engage the at least one recess. Two slots are arranged on the main plate body, and the two slots vertically extend from the upper and lower two end faces of the main plate body respectively; the auxiliary plate body has an attachment plate part and an insertion plate part integrally formed with the attachment plate part, and the insertion plate parts of the two auxiliary plate bodies are inserted into the two slots from above and below the main plate body respectively and can move along the slots; wherein: A tongue part is cut in the middle area of the insertion plate part, and the head part of the tongue part faces the attachment plate part; the tongue part is obtained by cutting elastic strips connected to each other on the tongue part to allow the tongue part to be elastically deformed, and the head part of the tongue part is provided with a positioning hole; The area of the main plate body opposite to the positioning hole is provided with a pin hole, and a pin shaft is arranged at the pin hole, the pin shaft passes through the positioning hole, so that when the auxiliary plate body moves away from the main plate body, the elastic strips are elastically deformed by the limiting of the head part of the tongue part by the pin shaft to allow the auxiliary plate body to be elastically moved.

8. The intervertebral fusion device of claim 7, wherein: The positioning hole is configured as an oblong hole with a size in the length direction of the tongue part greater than a size in the width direction of the tongue plate; A threaded hole is formed from the end of the pin shaft, a radial hole is formed in the pin shaft and passes through the threaded hole, the radial hole faces the hole wall of the positioning hole in the insertion direction of the insertion plate part, a top bead is arranged in the radial hole, and a top pin with a tapered head is screwed into the threaded hole, the tapered surface of the top pin pushes the top bead radially outward to push against the hole wall of the positioning hole by screwing the top pin.

9. The spinal fusion device according to claim 1, wherein, A spacing part is arranged at the inner end of the through hole, the spacing part has a sleeve body and a plurality of finger-shaped elastic strips integrally formed with the sleeve body and arranged circumferentially to form a trumpet-shaped outer shape; the inner end of the through hole is provided with a insertion hole, the sleeve body is inserted into the insertion hole, and the bone screw passes through the sleeve body; wherein: When the head of the bone screw is screwed into the vertebra and tightened, the finger-shaped elastic strips are deformed to fit and press against the front surface of the vertebra.

10. The spinal fusion device according to claim 3, wherein, The rear side of the spherical cavity of the cage body is configured with a avoiding slot for accommodating the tapered end of the distal end of the rod of the linear part.

11. The spinal fusion device according to claim 1, wherein, The cage body is made of polyether ether ketone material; the cross section of the bone graft window of the cage body is rectangular; the size of the window of the bone graft window is greater than the size of the middle area of the bone graft window; and the sharp bodies are rectangularly arranged multiple four-pyramid bodies.

12. The spinal fusion implant of claim 3, wherein: The bone plate is made of titanium alloy material, the tube body and the rod body of the linear component are both made of titanium alloy material, and the tube body is made of two different titanium alloy materials; the titanium alloy for making the bone plate and the rod body includes Ti-6Al-4V; the titanium alloy material for making the tube body includes any one of Ti-6Al-4V and both Ti-13Nb-13Zr and Ti-12Mo-6Zr-2Fe.

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