A posterior lumbar spine zero-profile fusion device, an insertion system and an insertion method

Abstract

The present invention discloses a posterior lumbar spine zero-notch fusion device, an insertion system and an insertion method. After the fusion device of the present invention is inserted between vertebrae, the expansion angle of the expansion part connected to the fixed part of the fusion device is controlled by the screwing depth of the expansion nail, and the selected depth of the expansion nail can be selected according to the actual situation to meet the expansion height between different vertebrae; at the same time, the fusion device of the present invention is unilaterally expanded, that is, the expansion part is expanded toward one side of the upper vertebral body. After expansion, the fusion device located on the posterior side of the vertebral body can not only stably and effectively lift the front column of the upper vertebral body upward to restore the physiological curvature of the front column of the upper vertebral body compared to the fusion device located on the anterior side of the vertebral body. Moreover, the fixed part of the fusion device is locked to the upper vertebral body and the lower vertebral body respectively by locking nails, so as to ensure that the fusion device does not shift after expansion, and also avoid the problem of fusion device displacement caused by vertebral activity compression when the human body moves after surgery, so as to keep the position of the fusion device between the vertebrae stable and unchanged.

Description

Technical Field

[0001] The invention relates to the technical field of posterior lumbar implantation, and in particular to a posterior lumbar zero-profile fusion device, an implantation system and an implantation method. Background Art

[0002] A lumbar fusion device is a device that is implanted between the upper and lower vertebrae after spinal canal resection and disc resection in order to restore the normal height of the intervertebral space and the physiological curvature of the lumbar spine and enable the upper and lower vertebrae to fuse together more stably after disc resection.

[0003] In the early days, only fusion cages were implanted. After surgery, the fusion cages slipped into the spinal canal and failed to form bony fusion with the upper and lower vertebrae. The current common practice is to add upper and lower pedicle screws and rods for fixation after implantation of the fusion cage. This practice greatly reduces the postoperative slippage of the fusion cage and significantly improves the fusion rate of the upper and lower vertebrae.

[0004] Due to individual differences and the uncertainty of vertebral endplate surface, even if pedicle screws and rods are used for fixation, the fusion device slips and does not fuse. In order to solve this problem, some scholars have invented expansion fusion devices and threaded fusion devices, which are helpful to prevent the slippage of the fusion device, but pedicle screws and rods are still required for fixation. Due to the addition of pedicle screws and rods for fixation, the surgical risk, operation time and surgical cost are greatly increased. In recent years, a zero-profile intervertebral fusion vertebra has been invented, that is, two sets of oblique locking screws are added to the tail end of the fusion device, so that the upper and lower vertebrae can be fixed immediately, eliminating the need for pedicle screws and rods or plate fixation, and has been widely used in cervical fusion. The application of anterior lumbar zero-profile fusion devices has also been carried out abroad, but the disadvantages of anterior lumbar zero-profile fusion devices are: after spinal canal decompression and disc removal, another anterior incision is required to place the fusion device, which is more traumatic.

[0005] Although there is a proposal for a zero-profile posterior lumbar fusion device, the advantages of a zero-profile posterior lumbar fusion device are that the fusion device can be placed after spinal canal decompression and discectomy without making another incision. However, its actual application is more difficult than the anterior lumbar fusion device. For example, a posterior lumbar interbody fusion system disclosed in Chinese invention patent CN109806034A affects the line of sight due to the obstruction of the hard capsule, the nerve root meridian, the intraspinal venous plexus, the fat tissue, the residual annulus fibrosus, and the hyperplastic osteophyte tissue, making it almost impossible to place the fusion device in the intervertebral space and then insert the locking screw. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a posterior lumbar zero-profile fusion device, an insertion system and an insertion method.

[0007] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0008] In a first aspect, a method for inserting a posterior lumbar zero-profile fusion device comprises the following steps:

[0009] After completing the posterior lumbar spinal canal decompression and discectomy surgery, the fusion device and the impactor are detachably connected into one body and then driven into the space between the upper vertebra and the lower vertebra from the posterior lumbar spine, with the expansion part of the fusion device facing the side of the upper vertebra; the expansion nail is passed through the head of the impactor and entered into the expansion hole of the fusion device, and the expansion nail is screwed into the expansion hole by a screwdriver and one end is passed through and abutted against the expansion part, so that it is expanded upward to abut and lift up the front column of the upper vertebra, and the expansion nail is stopped from being screwed in after the expansion part is expanded to a preset height; the fixing part of the fusion device is locked in the upper vertebra and the lower vertebra respectively by passing the locking nail through the head of the impactor; wherein,

[0010] The fusion device comprises:

[0011] A fixing part, used for locking on the upper vertebral body and the lower vertebral body of the lumbar spine;

[0012] An expansion part, the expansion part is rotatably connected to the upper side of the fixing part so as to rotate relative to the fixing part, and the expansion part is used to expand upward to abut against and lift up the front column of the upper vertebral body;

[0013] The nail entry opening on the head for the opening nail and the locking nail to enter is at least 1 cm away from the fusion device.

[0014] In a second aspect, a posterior lumbar spine zero-profile fusion device is provided, comprising:

[0015] A fixing part, used for locking on the upper vertebral body and the lower vertebral body of the lumbar spine;

[0016] The expansion part is rotatably connected to the upper side of the fixing part so as to rotate relative to the fixing part, and the expansion part is used to expand upward to abut against and lift up the front column of the upper vertebral body.

[0017] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, an expansion hole is provided in the middle of the fixing portion, and the fusion device also includes an expansion nail, which is used to be threadedly connected to the expansion hole, and one end of the expansion nail passes through the expansion hole and abuts against the expansion portion to push it open.

[0018] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, one end of the expansion portion is rotatably connected relative to the fixing portion, and a ramp is provided on one side of the lower portion of the expansion portion, and the ramp is used to abut against the expansion nail.

[0019] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, in an initial state, the high end of the inclined platform is located above the top of the expansion hole or its extended area, and the low end of the inclined platform is located below the axis of the expansion hole.

[0020] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, the inclined platform is provided with a top slot with an arc-shaped longitudinal section, and the top end of the open nail abuts in the top slot.

[0021] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, the upper and lower sides of the fixing portion are respectively provided with upper oblique holes and lower oblique holes, so that locking screws can be screwed into the upper oblique holes and lower oblique holes and respectively passed through the upper vertebral body and the lower vertebral body to realize locking and fixation of the fusion device; the line-plane angle between the central axis of the upper oblique hole and the upper side surface of the fixing portion is 30~40°; the line-plane angle between the central axis of the lower oblique hole and the lower side surface of the fixing portion is 30~40°.

[0022] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, the fixing portion is provided with an avoidance groove on the right side of the expansion hole to avoid the expansion nail being screwed in.

[0023] As a preferred embodiment of the posterior lumbar zero-profile fusion device provided by the present invention, the fixing portion is further provided with a connecting hole for facilitating threaded connection with the impactor to achieve detachable connection between the fusion device and the impactor; the connecting hole is coaxially arranged with the expansion hole.

[0024] In the third aspect, a posterior lumbar zero-profile fusion device insertion system comprises an insertion device and the above-mentioned fusion device; the insertion device comprises a sleeve, a head and a hollow screw with a tail cap; the head is connected to the sleeve, and a through hole is provided in the middle of the head, which is communicated with the sleeve; the hollow screw is sleeved in the sleeve and the through hole, one end of the hollow screw close to the tail cap is threadedly connected to the sleeve, and the end of the hollow screw away from the tail cap is threadedly connected to the fusion device; the head is also provided with an upper oblique channel and a lower oblique channel, and after the head is connected to the fusion device accordingly, the upper oblique channel corresponds to the upper oblique hole, and the lower oblique channel corresponds to the lower oblique hole; the hollow screw is also provided with avoidance openings in the areas corresponding to the upper oblique channel and the lower oblique channel.

[0025] As a preferred embodiment of the driving system of the posterior lumbar zero-profile fusion device provided by the present invention, the hollow screw and the sleeve are provided with an observation port above the head. As a preferred embodiment of the driving system of the posterior lumbar zero-profile fusion device provided by the present invention, the fixing portion of the fusion device is also provided with a positioning groove, and the head of the driving device is correspondingly provided with a positioning block matched with the positioning groove.

[0026] The present invention has the following beneficial effects:

[0027] The posterior lumbar spine zero-notch fusion device and insertion method provided by the present invention, after the fusion device is inserted between the vertebrae, the expansion angle, i.e., the height, of the expansion part connected to the fixed part of the fusion device is controlled by the screwing depth of the expansion nail, and the selected depth of the expansion nail can be selected according to the actual situation to meet the expansion height between different vertebrae; at the same time, the fusion device of the present invention is unilaterally expanded, i.e., the expansion part is expanded toward one side of the upper vertebral body, and after expansion, the fusion device located on the posterior side of the vertebral body is compared with the fusion device located on the anterior side of the vertebral body. Such a design can not only stably and effectively lift the front column of the upper vertebral body upward to restore the physiological curvature of the front column of the upper vertebral body. Moreover, the fixed part of the fusion device is locked to the upper vertebral body and the lower vertebral body respectively by locking nails, so as to ensure that the fusion device does not shift after expansion, and also avoid the problem of displacement of the fusion device caused by vertebral activity compression when the human body moves after surgery, so as to keep the position of the fusion device between the vertebrae stable and unchanged.

[0028] The present invention also uses a specific impactor for use with the fusion device of the present invention. The head of the impactor of the present invention is embedded in the positioning groove of the fusion device through a positioning block to achieve pre-positioning and avoid the problem of synchronous rotation during threaded connection. The hollow screw provided in the head of the impactor is not only used to connect the impactor and the fusion device, but also to provide an entry channel for the opening nail; an upper oblique channel and a lower oblique channel are also provided in the head of the impactor. Since the height of the head of the impactor is controlled at 1.0~1.5cm, it is higher than nerve tissues such as nerve roots and dura mater sacs. When the opening nail is screwed in and the fixing part is locked, the opening nail, locking nail and screwdriver are only operated in the hollow screw, the upper oblique channel and the lower oblique channel, and do not contact any peripheral nerves and tissues, so as to prevent accidents of damaging the peripheral nerve tissues of the vertebral body during the process of screwing in the opening nail and locking nail.

[0029] The present invention combines the height increaseability and immediate fixation of the fusion device. The expansion part of the fusion device near the front road can be used to increase the height, restore the height of the front column of the lumbar space and the physiological curvature of the lumbar spine; the fixing part of the fusion device near the back road can be fixed with locking nails to fix the upper and lower vertebrae immediately without displacement. Then, through a specific inserter, the operation interface of inserting nails (opening nails and locking nails) and expanding the height of the fusion device is raised more than 1 cm toward the back road. In this way, the operations of inserting nails and expanding the height after the fusion device is inserted are far away from the nerve roots and dura mater sac, ensuring a clear field of vision. The inserting process is carried out in the inserter to avoid damage to the nerve roots. It not only simplifies the actions of inserting nails and expanding, but also greatly reduces the risk of surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of the fusion device according to Example 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of an exploded view of a fusion device according to Example 1 of the present invention;

[0032] Figure 3 It is a top view of the fusion device of Example 1 of the present invention;

[0033] Figure 4 for Figure 3 Sectional view at AA in the middle;

[0034] Figure 5 This is a schematic diagram of the structure of the fixing part of the fusion device in Example 1 of the present invention;

[0035] Figure 6 This is a schematic structural diagram of the expansion portion of the fusion device in Example 1 of the present invention;

[0036] Figure 7 This is a schematic diagram of the structure of the fusion device being expanded and locked in Example 1 of the present invention;

[0037] Figure 8 It is a sectional stereoscopic view at AA of Example 1 of the present invention when the fusion device is expanded to a certain height and locked;

[0038] Fig. 9 It is a sectional stereoscopic view of the AA position when the fusion device of Example 1 of the present invention is expanded to another height and then locked;

[0039] Fig.10 This is a structural cross-sectional view of the early design 1 of the fusion device of the present invention;

[0040] Fig.11 This is a structural cross-sectional view of the early design 2 of the fusion device of the present invention;

[0041] Fig.12 This is a schematic diagram of the structure of a driver in a driving system according to Embodiment 2 of the present invention;

[0042] Fig.13 This is an exploded schematic diagram of a driver in a driver system according to Embodiment 2 of the present invention;

[0043] Fig.14 A top view of a driver in a driving system according to Embodiment 2 of the present invention;

[0044] Fig.15 A cutaway stereogram of the middle BB;

[0045] Fig.16 for Fig.15 The local schematic diagram of the C in the middle;

[0046] Fig.17 A schematic diagram of the structure of the hollow screw and the tail cap in the driving system in Example 2 of the present invention;

[0047] Fig.18 This is a schematic diagram of the connection between the driver and the fusion device in the driver method of Example 3 of the present invention;

[0048] Fig.19 It is a schematic diagram of the structure after the driver and the fusion device are connected in the driver method of Example 3 of the present invention;

[0049] Fig. 20 It is a schematic diagram of the structure of screwing in the opening nail and the locking nail in the driving method of embodiment 3 of the present invention;

[0050] Fig.21 It is a sectional stereoscopic diagram of the process of opening and screwing in the nail in the driving method of embodiment 3 of the present invention;

[0051] Fig. 22 It is a sectional stereoscopic diagram of the locking nail entry and screwing-in process in the driving method of embodiment 3 of the present invention. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0053] Example 1

[0054] Please refer to Figure 1-9Embodiment 1 of the present invention provides a posterior lumbar zero-profile fusion device, which includes a fixing portion 110 and a distraction portion 120, wherein the distraction portion 120 is rotatably connected to the upper side of the fixing portion 110 to rotate relative to the fixing portion 110. The fixing portion 110 is used to lock on the upper vertebral body and the lower vertebral body of the lumbar spine, and the distraction portion 120 is used to distract upward so that an upward slope appears on the upper side of the fusion device 100, that is, when the fusion device 100 is driven between the upper vertebral body and the lower vertebral body of the lumbar spine, the distraction portion 120 is pushed open by opening the nail to rotate relative to the fixing portion 110, and the front column of the upper vertebra is distracted upward to abut and push up the fixing portion 110, and the fixing portion 110 is locked in the upper vertebral body and the lower vertebral body respectively by the locking nail 170.

[0055] like Figure 1 , 2 , 4 and 5, the fixing portion 110 is similar to an L-shaped structure, specifically, the fixing portion 110 includes an integral left fixing block 111 and a right fixing block 112. A spreading hole 113 is provided in the middle of the left fixing block 111, and a first thread is provided in the spreading hole 113. An expansion pin 130 having a second thread matched with the first thread can be screwed into the spreading hole 113 and one end of the expansion pin 130 passes through the spreading hole 113 and abuts against the spreading portion 120 to push it open. The height of the spreading pin 130 pushing the spreading portion 120 open can be controlled by the depth of the expansion pin 130 screwed into the spreading hole 113. The upper and lower sides of the left fixing block 111 are respectively provided with an upper inclined hole 114 and a lower inclined hole 115, and the upper and lower inclined holes 114 and 115 are both provided with a fourth thread, so that a locking nail 170 having a fifth thread matching the fourth thread can be screwed into the upper and lower inclined holes 114 and 115 and passed through to be nailed into the upper vertebral body and the lower vertebral body respectively, so as to realize the locking fixation of the fusion device 100.

[0056] The middle portion of the right fixing block 112 is provided with an avoidance groove 116. Figure 5 As shown, it is convenient to avoid the open nail 130, that is, not hinder the advancement of the open nail 130, and is used to support the open nail 130.

[0057] Preferably, if Figure 4 As shown, the line-plane angle a between the central axis of the upper inclined hole 114 and the upper side surface of the left fixing block 111 is 30-40°, preferably 32-37°, and more preferably 32-35°. Correspondingly, the line-plane angle a between the central axis of the lower inclined hole 115 and the lower side surface of the left fixing block 111 is 30-40°, preferably 32-37°, and more preferably 32-35°. Such a design not only helps to control the depth of the locking nail 170 being driven into the upper vertebral body and the lower vertebral body, but also avoids the angle being too high or too low, resulting in loose locking or too deep driving.

[0058] Preferably, a connection hole 117 is further provided on the left side surface of the left fixing block 111, and the connection hole 117 is provided with a sixth thread, which is convenient for threaded connection with the driver 200, so as to realize the detachable connection between the fusion device 100 and the driver 200. The connection hole 117 is coaxially arranged with the expansion hole 113, and the aperture of the connection hole 117 is larger than the aperture of the expansion hole 113, wherein the aperture size of the connection hole 117 satisfies that after the hollow screw 220 of the driver 200 is threadedly connected to the connection hole 117, the expansion nail 130 can smoothly pass through the hollow of the hollow screw 220 and pass through the connection hole to enter the expansion hole 113.

[0059] Preferably, a locking groove 118 is further provided on the periphery of the left side of the left fixed block 111, and a locking block 212 is correspondingly provided on the driver 200. After the locking block 212 is aligned and embedded in the locking groove 118, it prevents the driver 200 from rotating synchronously with the left fixed block 111 when being threadedly connected, thereby affecting the connection effect and disassembly. The locking groove 118 can be provided on the upper and lower sides of the left fixed block 111, or on the front and rear sides, or on any two of the upper and lower sides, or on other positions.

[0060] like Figure 1 , 2 As shown in FIGS. 4 and 7-9 , the expansion portion 120 is disposed above the right fixed block 112 , and the left end of the expansion portion 120 can rotate relative to the left fixed block 111 . Specifically, the expansion portion 120 is rotatably connected to the left fixed block 111 through the rotating shaft 140. Specifically, the two sides of the left end of the expansion portion 120 are provided with rotating portions 123, and correspondingly, the left fixed block 111 is provided with a rotating groove 119. During specific assembly, the rotating portion 123 is embedded in the rotating groove 119, and then the rotating shaft 140 is inserted to realize the rotation of the rotating portion 123 in the rotating groove 119. At the same time, the rotating groove 119 half-covers the rotating portion 123, which is not only conducive to the stable rotation of the rotating portion 123 in the rotating groove 119, but also prevents the right end of the expansion portion 120 from being subjected to excessive downward pressure when it is expanded, which will be transmitted to the rotating portion 123 through the top point of the opening nail as a lever fulcrum, causing it to tilt and detach from the left fixed block 111, that is, the expansion portion 120 is in a free state and cannot play a role in supporting the upper vertebral body.

[0061] In the initial state of the expansion portion 120 , ie before expansion, the upper side surface thereof is flush with or almost flush with the upper side surface of the left fixing block 111 . Such a design is conducive to inserting the fusion cage 100 between vertebral bodies.

[0062] In the early development of the present inventor, a vertically symmetrical expansion portion was integrally extended and connected to the right side of the left fixed block, such as Fig.10 As shown, the expansion part is pushed open by the expansion nail through its own elasticity. When the expansion nail enters and abuts against the expansion part, the two symmetrical expansion parts are pushed open synchronously, thereby increasing the height of the fusion device. However, in actual practice, it is found that since the fusion device is placed in the human body, its material must be medical titanium or its alloy material. However, medical titanium or its alloy material is very brittle. During the expansion process of the expansion nail, the expansion part is opened by its own elastic force, which is prone to brittle fracture, that is, the fusion device is directly scrapped. In order to solve this problem, the inventor rotatably connects the upper and lower expansion parts to the left fixed block through a rotating shaft, that is, when the upper and lower expansion parts are pushed open by the expansion nail, they are rotated by the rotating shaft, such as Fig.11 As shown, the problem of brittle fracture is avoided. However, in actual practice, the fusion device needs to be knocked by external force before it can be inserted into the upper vertebral body and the lower vertebral body. In this process, the upper and lower expansion parts will be squeezed and deformed. After insertion, the fusion device is displaced, that is, the fusion device is laterally displaced, and the expansion part cannot directly correspond to the upper vertebral body and the lower vertebral body, that is, the abutment contact area is small, and it is difficult to achieve the effect of restoring the height between the vertebrae and the physiological curvature. In order to further solve this new technical problem, the inventor only uses one expansion part 120, and the side corresponding to the expansion part 120 is the right fixed block integrally connected to the left fixed block. In this way, when knocking the fusion device, the lateral displacement caused by deformation is effectively reduced, ensuring that the expansion part 120 can directly correspond to the upper vertebral body after insertion. When it is subsequently pushed open, the rotating shaft 140 smoothly reaches the preset height and is in a stable expanded state. At the same time, the fixing part 110 is locked between the vertebrae in combination with the locking nail 170 to ensure that the fusion device 100 does not shift, that is, the expanded height and expanded position of the expansion part 120 are in a stable state without shifting toward the posterior route or collapsing, and can significantly and effectively expand the anterior column of the upper vertebra stably upward to restore the height and physiological curvature of the upper vertebra.

[0063] The right opening end of the fusion device 100 is stretched and raised by the stretching nail 130, but the following problems are found: the adjustability of the stretching height at the right opening end alone generally cannot achieve the expected recovery effect, and the stretching nail 130 needs to be screwed in to a deeper depth. If an error occurs, in order to further raise the height, the stretching nail 130 is screwed in too deep and passes through the fusion device 100 and reaches the aorta, there is a high risk of massive bleeding. In order to solve this new technical problem, the inventors have also provided an inclined platform 121 on the side of the stretching portion 120 facing the right fixing block 112, so as to facilitate the adjustment of the stretching height of the stretching portion 120 according to the gap conditions between different vertebrae, and to more effectively adjust the stretching height, such as Figure 8 ,9 shown.

[0064] Furthermore, if Figure 4 As shown, in the initial state, the high end 1211 of the inclined platform 121 is located above the top of the expansion hole 113 or its extended area, and the low end 1212 of the inclined platform 121 is located below the axis of the expansion hole 113, such as slightly higher than or located at the bottom of the expansion hole extension area. The horizontal length L of the high end 1211 and the low end 1212 of the inclined platform 121 is controlled at 7~9mm, which is convenient for controlling the screw-in depth of the opening nail 130. The inclination angle β of the inclined platform is controlled at 25~35°, preferably 28~32°, and can also be other angles. Furthermore, the outer diameter of the top opening end 131 of the opening nail 130 can be 4~5mm. With such a design, when the expansion pin is screwed into the right middle part of the right fixing block, it can be expanded to a sufficient height and can be raised by two levels. The level here can be understood as the original fusion device height is 10mm, and the height after expansion is generally 12mm (that is, 1 level). The height after expansion can reach 13-15mm through the design of the inclined platform of the present invention.

[0065] At the same time, the right end of the inclined platform 121 stops at the right side of the middle part of the expansion part 120, and does not extend to the right end. Even if it is screwed into the rightmost end of the inclined platform 121, the expansion nail 130 is always inside the fusion device 100, reducing the risk of squeezing the aorta due to the expansion nail being screwed out of the fusion device during surgery.

[0066] The inclined platform 121 is used to abut against the opening nail 130. Through the design of the inclined platform 121, the opening nail 130 abuts against the inclined platform 121 and then pushes the expansion part 120 to start. As the opening nail 130 enters deeper, the expansion height of the expansion part 120 is adjusted. The deeper the opening is, the higher the expansion height is. The spacing between the upper vertebral body and the lower vertebral body of the patient's body varies in size. The expansion part 120 is pushed to a suitable height through the screwing depth of the opening nail 130, which is more flexible to adapt to vertebral bodies with different spacings and also reduces the amount of bone fragments filled.

[0067] In order to better match and abut the opening pin 130 and provide a stable opening effect, the inclined platform 121 is provided with an arc-shaped opening groove 124, such as Figure 6 As shown, the top open end of the expansion nail 130 abuts against the top open groove 124 .

[0068] A limiting groove 122 is provided at the upper left side of the expansion portion 120 near the left fixing block 111. When the expansion portion 120 is expanded upward, the limiting groove 122 is used to abut against the left fixing block 111 to limit the expansion angle of the expansion portion to avoid the expansion nail 130 from being excessively expanded and broken after being screwed in too much.

[0069] The right part of the right fixing block 112 is provided with a transverse filling hole 150 for filling artificial bone material. The right part of the expansion part 120 is also provided with a transverse filling hole 150. The artificial bone is filled in the transverse filling hole and can be integrated with the lumbar spine, which is convenient for accelerating postoperative recovery.

[0070] In the present invention, the outer surfaces of the right fixing block 112 and the expansion portion 120 are provided with corrugations 160 , which help to improve the connection between the fusion cage 100 and the vertebral body.

[0071] Example 2

[0072] like Figure 12-17 As shown, Example 2 of the present invention provides a posterior lumbar zero-profile fusion device insertion system, which includes an insertion device and the fusion device shown in Example 1.

[0073] like Figure 12-16 As shown, the driver 200 includes a sleeve 230, a head 210 and a hollow screw 220 with a tail cap 240. The head 210 is detachably connected to the fusion device 100, so that the fusion device 100 is connected through the head 210 and then driven between the upper vertebral body and the lower vertebral body. A through hole 211 is opened in the middle of the head 210. The head is connected to the sleeve 230, and a through hole 211 is opened in the middle of the head, which is connected to the sleeve 230 and coaxially arranged; the hollow screw is sleeved in the sleeve 230 and the through hole 211, and one end of the hollow screw close to the tail cap 240 is threadedly connected to the sleeve 230, and the end of the hollow screw away from the tail cap 240 is threadedly connected to the fusion device; the hollow screw 220 is driven to move in the sleeve 230 by rotating the tail cap 240, and can be screwed in and out relative to the head 210. After being screwed out, the front end thread 222 of the hollow screw 220 is threadedly connected to the connecting hole 117 of the fusion device, so that the fusion device and the inserter are connected to form an integrated structure.

[0074] The positioning block 212 is arranged on the head 210. In specific implementation, the head 210 is pre-positioned with the fusion device 100 after the positioning block 212 is inserted into the slot of the fusion device 100, and the hollow screw 220 is rotated into the connecting hole 117, and the head 210 and the fusion device 100 are connected together through the threaded connection of the hollow screw 220, and the reverse operation can be performed when separating. With such a structural design, the synchronous rotation affecting the disassembly and assembly during the threaded connection is avoided by the simple coordination of the positioning block 212 and the positioning slot 118, and there is no need for complex structural designs such as grippers, buckles and other structures, which reduces the difficulty of manufacturing and disassembly and assembly.

[0075] like Fig.17 As shown, the hollow design of the hollow screw 220, after the hollow screw 220 is threadedly connected to the fixing part 110 of the fusion device 100, the hollowness of the hollow screw 220 corresponds to the expansion hole 113, so that it is convenient for the screwdriver to drive the expansion pin 130 through the hollowness into the expansion hole 113, and then the screwing depth of the expansion pin 130 is controlled by rotating the screwdriver.

[0076] Preferably, the hollow screw and the sleeve 230 are provided with an observation port 250 above the head. The opening nail is brought in from the side of the tail cap 240 by a screwdriver, passes through the sleeve and the head in sequence, and finally enters the expansion hole. However, the screwdriver is only a wedge-shaped head inserted into the notch of the opening nail, and is not fixedly connected. Due to the long length of the sleeve, the screwdriver may be dislocated or offset from the opening nail during the movement of the sleeve, which is not conducive to subsequent screwing in. By providing the observation port 250 above the head, the connection between the screwdriver and the opening nail can be observed, and if any problem is found, it can be manually adjusted through the observation port 250.

[0077] like Fig.16As shown, the head 210 is also provided with an upper oblique channel 213 and a lower oblique channel 214. After the head 210 is connected to the fusion device 100, the upper oblique channel 213 corresponds to the upper oblique hole 114, and the lower oblique channel 214 corresponds to the lower oblique hole 115. With such a design, the locking nail 170 can directly enter from the entrance end 215 of the upper oblique channel 213 and the lower oblique channel 214, without entering from the upper oblique hole 114 and the lower oblique hole 115 of the fusion device 100. The height h of the head 210 is controlled to be 1.0-1.5 cm, preferably, controlled to be 1.2-1.5 cm, and can also be higher than 1.5 cm, so that the entrance end 215 (i.e., the nail entry) of the upper oblique channel 213 and the lower oblique channel 214 is completely higher than nerve tissues such as nerve roots and dura mater sacs. When performing upper locking, the locking nail 170 and the screwdriver only operate in the upper inclined channel 213 and the upper inclined hole 114, and do not contact any peripheral nerves and tissues, so as to prevent the accidental damage to the peripheral nerve tissue of the vertebral body during the screwing of the locking nail 170.

[0078] Furthermore, if Fig.17 As shown, the hollow screw 220 is also provided with avoidance openings 221 in the areas corresponding to the upward inclined channel 213 and the downward inclined channel 214 to avoid affecting the entry of the locking pin 170 and the screwdriver.

[0079] In order to facilitate hand-held operation of the driver, a hand-held portion 260 is connected to the sleeve 230 at a side close to the tail cap 240 .

[0080] Example 3

[0081] like Figure 18-22 As shown, Embodiment 3 of the present invention provides an application method of the fusion device 100, that is, an insertion method, which includes the following steps:

[0082] After completing the posterior lumbar spinal canal decompression and discectomy surgery, the fusion device and the impactor are detachably connected into one body, and then the fusion device is driven into the space between the upper vertebra and the lower vertebra from the posterior lumbar spine, with the expansion portion of the fusion device facing the side of the upper vertebra; the expansion nail is passed through the impactor and entered into the fusion device, and abuts against the expansion portion, so that it is expanded upward to abut and lift the front column of the upper vertebra, and the expansion nail is stopped from being screwed in after the expansion portion is expanded to a preset height; the fixing portion of the fusion device is locked in the upper vertebra and the lower vertebra by the locking nail 170, and the impactor is removed.

[0083] Specifically,

[0084] like Fig.18As shown, after the head 210 of the driver 200 and the fixing part 110 of the fusion device 100 are aligned by the positioning block 212 being embedded in the positioning groove 118; the tail cap 240 is rotated to drive the hollow screw to move in the sleeve 230, the head is screwed out and then threadedly connected with the connecting hole of the fixing part 110, so as to complete the connection between the driver 200 and the fusion device 100, as shown in FIG. Fig.19 As shown;

[0085] After the posterior spinal canal decompression and discectomy are completed, the fusion device 100 is driven into the space between the upper vertebra and the lower vertebra by the driving device 200 (specifically, the tail cap 240 of the driving device 200 is knocked step by step). After the driving device 100 is driven into the space between the upper vertebra and the lower vertebra, the expansion part 120 faces the upper vertebra.

[0086] After the screwdriver is connected to the opening nail 130, the wedge-shaped head of the screwdriver (not shown) is inserted into the notch of the opening nail, and then enters the hollow screw from one side of the tail cap 240 (such as Fig. 20 , 21 As shown), gradually go down, observe the connection between the screwdriver and the opening nail when passing through the observation port 250, if there is any deviation, manually adjust it at the observation port 250, and then pass through the head into the expansion hole; screw the expansion nail into the expansion hole with the screwdriver, the front end of the expansion nail abuts against the inclined platform 121 of the expansion part 120, and control the screwing depth of the expansion nail 130 according to actual needs. After reaching a preset height, stop screwing the expansion nail 130 (as shown in FIG. Fig.21 ), and remove the screwdriver.

[0087] Then, if Fig. 20 , 22 As shown, the upper vertebra is locked: the locking nail 170 is placed from the upper oblique channel 213 into the upper oblique hole 114, and the locking nail 170 is rotated and screwed into the upper vertebra by a screwdriver; then the lower vertebra is locked: the locking nail 170 is placed from the lower oblique channel 214 into the lower oblique hole 115, and the locking nail 170 is rotated and screwed into the lower vertebra by a screwdriver, completing the locking and fixing of the fusion device 100. Finally, the hollow screw 220 is rotated to unscrew it from the connecting hole 117, and the positioning block 212 is moved out of the positioning groove 118, so that the head 210 is separated from the fusion device 100, and the driver 200 can be taken away.

[0088] The above-mentioned embodiments merely express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. Any technical solution obtained in the form of equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.

Claims

1. A posterior lumbar spine zero-profile fusion cage, characterized in that: It includes: A fixing part, used for locking on the upper vertebral body and the lower vertebral body of the lumbar spine; the fixing part comprises an integrated left fixing block and a right fixing block; An expansion part, the expansion part is rotatably connected to the upper part of the right fixing block of the fixing part so as to rotate relative to the right fixing block of the fixing part, and the expansion part is used to expand upward to abut against and lift up the front column of the upper vertebral body; The middle part of the left fixing block is provided with an expansion hole; the fusion device further comprises an expansion nail, which is used to be threadedly connected with the expansion hole, and one end of the expansion nail passes through the expansion hole and abuts against the expansion part to push it open; One end of the expansion part is rotatably connected with the fixing part, and a slope is provided on one side of the expansion part facing the right fixing block, and the slope is used to abut against the expansion nail; The inclination angle β of the ramp is controlled at 25-35°, and the right end of the ramp stops at the right side of the middle part of the opening part; a limiting groove is provided at the upper left part of the opening part near the left fixed block; the opening part is rotatably connected to the left fixed block through a rotating shaft, and rotating parts are provided on both sides of the left end of the opening part, and the left fixed block is correspondingly provided with a rotating groove, the rotating part is embedded in the rotating groove, and then the rotating shaft is inserted to realize the rotation of the rotating part in the rotating groove, and at the same time, the rotating groove half covers the rotating part; In an initial state, the high end of the ramp is located above the top of the opening hole or its extended area, and the low end of the ramp is located below the axis of the opening hole.

2. The posterior lumbar zero-profile fusion cage according to claim 1, characterized in that: The inclined platform is provided with a top slot with an arc-shaped longitudinal section, and the top end of the open nail abuts against the top slot.

3. The posterior lumbar zero-profile fusion cage according to claim 1, characterized in that: The upper and lower sides of the fixing part are respectively provided with an upper inclined hole and a lower inclined hole, and the upper and lower inclined holes are both provided with internal threads, so that locking nails with external threads can be screwed into the upper and lower inclined holes and passed through and respectively nailed into the upper vertebral body and the lower vertebral body to realize the locking fixation of the fusion device; the line-plane angle between the central axis of the upper inclined hole and the upper side surface of the fixing part is 30~40°; the line-plane angle between the central axis of the lower inclined hole and the lower side surface of the fixing part is 30~40°.

4. The posterior lumbar zero-profile fusion cage according to claim 3, characterized in that: The fixing portion is provided with an avoidance groove on the right side of the support hole to avoid the screwed-in expansion nail.

5. A posterior lumbar zero-profile fusion device insertion system, characterized in that: It includes an impactor and a posterior lumbar zero-profile fusion device as described in claim 3 or 4; the impactor includes a sleeve, a head and a hollow screw with a tail cap; the head is connected to the sleeve, and a through hole is provided in the middle of the head, which is connected to the sleeve; the hollow screw is sleeved in the sleeve and the through hole, one end of the hollow screw close to the tail cap is threadedly connected to the sleeve, and the end of the hollow screw away from the tail cap is threadedly connected to the fusion device; the head is also provided with an upper oblique channel and a lower oblique channel, and after the head is connected to the fusion device accordingly, the upper oblique channel corresponds to the upper oblique hole, and the lower oblique channel corresponds to the lower oblique hole; the hollow screw is also provided with avoidance openings in the areas corresponding to the upper oblique channel and the lower oblique channel.

6. The posterior lumbar zero-profile fusion device insertion system according to claim 5, characterized in that: The hollow screw and the sleeve are provided with observation ports above the head.

7. The posterior lumbar zero-profile fusion device insertion system according to claim 6, characterized in that: The fixing portion of the fusion device is also provided with a locking groove, and the head of the driver is correspondingly provided with a locking block matched with the locking groove.

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