Degradable developing positioning nail for lumbar foramen endoscope operation

Abstract

The invention relates to the technical field of foramen endoscope operation positioning nails, in particular to a degradable developing positioning nail for a lumbar foramen endoscope operation. According to the technical scheme, the nail comprises a threaded nail body and a nail cap fixedly connected to the end of the threaded nail body, and further comprises a marking structure arranged at the end of the nail cap and used for recognizing a positioning point; the torsion stress groove is formed in the operation end of the nail cap, and a lock rod groove piece is formed in the torsion stress groove; the end of the rectangular rod is connected with a lock head piece connected with the lock rod groove piece in a locked mode, and a springback piece is arranged at the tail end of the transmission rod. The torsion stress groove and the lock rod groove piece are formed in the end of the nail cap, and the lock head piece can be stably connected into the lock rod groove piece under the cooperation of the springback piece; the tapered end piece and the rectangular rod can be withdrawn quickly without loosening the threaded nail body subsequently, so that the positioning stability of the threaded nail body is remarkably improved; and the threaded nail body, the tip part and the nail cap are all made of degradable materials and do not need to be taken out after an operation, so that the operation safety and the patient comfort are improved.

Description

Technical Field

[0001] This application relates to the field of percutaneous endoscopic surgery positioning screw technology, and more particularly to a biodegradable radiopaque positioning screw for lumbar percutaneous endoscopic surgery. Background Technology

[0002] During lumbar percutaneous endoscopic surgery, a positioning structure is required. The traditional method involves first inserting a sleeve into the surgical area, then using anteroposterior and lateral X-ray fluoroscopy to determine the sleeve's position and indirectly determine the insertion direction of the endoscope. The endoscope is then inserted through the sleeve to complete the surgical procedure. The core of this structure is a single cylindrical sleeve without any special fixation or imaging design. Positioning is achieved through approximate contact between the sleeve and bony structures, which is not precise enough. It cannot accurately conform to bony landmarks, making secondary disorientation easy. Because the sleeve's position is confirmed by fluoroscopy, it inevitably shifts during endoscope insertion, requiring the surgeon to readjust and regain the field of view after the lens stabilizes, leading to positioning failure. Furthermore, without imaging design, the position can only be indirectly determined by the sleeve's outline, making positioning accuracy highly dependent on the fluoroscopic angle.

[0003] To overcome the aforementioned problems, medical Kirschner wires or guide wires are used as positioning devices. The Kirschner wires / guide wires are fixed to the target bony structure (such as the lamina or articular process) using a sleeve. After confirming the position with X-ray fluoroscopy, the Kirschner wires / guide wires are removed, and then the endoscope is inserted into the surgical area. The positioning device is a linear metal rod with a diameter of 1.0-1.2 mm, made of non-degradable medical metal, with a non-differentiated identification design, capable of positioning only one anatomical point at a time. Single-point positioning, because only one Kirschner wire / guide wire can be inserted at a time, cannot meet the needs of multi-field anatomical structure positioning; it occupies the surgical operation channel, and the Kirschner wire / guide wire must occupy the only surgical channel, and must be removed when using electrodes, drills and other instruments, resulting in short positioning time; the positioning point is not traceable, and if it gets lost again after removal, it cannot be found back to the original positioning point, and it cannot achieve stable positioning throughout the process; the material is non-degradable, and if it is accidentally left behind, it will cause a foreign body reaction in the body, requiring additional surgery to remove it; the connection between the sleeve and the positioning structure inevitably causes a certain degree of loosening and misalignment of the positioning structure when the sleeve is removed.

[0004] In view of this, this application proposes a biodegradable radiopaque positioning screw for lumbar percutaneous endoscopic surgery. Summary of the Invention

[0005] The purpose of this application is to address the technical problems pointed out in the background art by proposing a biodegradable radiopaque positioning screw for lumbar percutaneous endoscopic surgery.

[0006] The technical solution of this application: A biodegradable radiopaque positioning screw for lumbar percutaneous endoscopic surgery, comprising a threaded screw body and a screw cap fixedly connected to its end, and further comprising: A marking structure located at the end of the nail head is used for identifying the positioning point; A torsion groove is provided at the operating end of the nail head, and a locking rod groove is provided in the torsion groove; A rectangular rod has a locking head connected to its end, which is locked to a locking rod groove. A transmission rod for operating the locking head is connected through the rectangular rod. A spring-loaded component is provided at the end of the transmission rod. The rectangular rod is disengaged without touching the threaded pin body through the cooperation between the locking head and the locking rod groove.

[0007] Preferably, the locking rod groove includes a circular groove formed at the recessed end of the torsion force groove, and a pair of guide grooves are formed on the inner wall of the circular groove, both of which extend to the bottom of the circular groove. Both of the inlet grooves have a sliding groove at their bottom ends in a clockwise direction, and the inner wall of the circular groove has a pair of locking grooves located at the other ends of the two sliding grooves respectively.

[0008] Preferably, both of the sliding grooves are 90-degree arcs, and the depth of the locking groove is half that of the guide groove.

[0009] Preferably, the lock head includes a connecting groove formed at the bottom end of a rectangular rod, a lock rod is movably connected in the connecting groove, and protrusions are fixedly connected to both sides of the bottom end of the lock rod; When manipulating the threaded nail body, the two protrusions are inserted into the two guide grooves respectively. Then, press down on the transmission rod to insert the locking rod into the bottom of the round groove. Rotate the transmission rod and locking rod clockwise by 90 degrees to make the two protrusions slide to the two locking grooves respectively. Finally, under the rebound action of the spring, the two protrusions slide to the upper end of the two locking grooves respectively, so that the locking rod is positioned at the upper end of the nail head.

[0010] Preferably, the rectangular rod has a through groove with a through connecting slot, the transmission rod is fitted and movably connected in the through groove, the transmission rod is fixedly connected to the locking rod, and the outer end of the transmission rod is fixedly connected to a control block.

[0011] Preferably, the spring-loaded component includes a circular cavity formed at the end of the rectangular rod, and a spring is disposed inside the circular cavity, the spring being sleeved on the outside of the transmission rod.

[0012] Preferably, a sleeve is fixedly fitted on the side wall of the rectangular rod, and an anti-slip sleeve is fixedly connected to the outer surface of the sleeve.

[0013] Preferably, the marking structure is a slot, a cross slot, or a raised ring; The slotted groove and cross groove are formed on the end face of the nail head, and the convex ring is machined on the end side wall of the nail head.

[0014] Preferably, the torsional force groove is a rectangular groove, and the rectangular rod is inserted into the torsional force groove.

[0015] Preferably, the end of the threaded nail body away from the nail head is provided with a pointed end; The threaded nail body, tip, and head are made of magnesium alloy; The lock head and rectangular rod are made of stainless steel 316L or titanium alloy TC4.

[0016] Compared with the prior art, this application has the following beneficial technical effects: This application improves the stability of the threaded nail body positioning by opening a torsion force groove and a locking rod groove at the end of the nail head, and the locking head can be stably connected in the locking rod groove with the cooperation of the spring-loaded part. When manipulating the threaded nail body, the rectangular rod and the torsion force groove cooperate to apply force to the nail head and the threaded nail body, and the threaded nail body can be quickly and without loosening afterward withdrawing from the locking head and the rectangular rod. By setting a marking structure at the end of the nail head, the problem of difficulty in distinguishing positioning points is solved, enabling rapid identification of different anatomical positioning points and avoiding confusion; In this application, the threaded nail body, tip, and nail head are all made of biodegradable materials, eliminating the need for postoperative removal and improving surgical safety and patient comfort. Attached Figure Description

[0017] Figure 1 This is a three-dimensional image of a biodegradable radiopaque positioning screw used in percutaneous endoscopic lumbar discectomy. Figure 2 This is a structural schematic diagram of the lock head component in this application; Figure 3 This is a cross-sectional view of the rectangular rod and the lock head in this application; Figure 4 yes Figure 3 Enlarged structural diagram at point A in the middle; Figure 5 These are schematic diagrams illustrating various implementations of the marker structure in this application; Figure 6 This is a structural schematic diagram of the locking rod groove component in this application; Figure 7 yes Figure 1 A cross-sectional view of the center nail head.

[0018] Reference numerals: 1. Threaded nail body; 2. Tip; 3. Nail head; 4. Marking structure; 41. Slotted groove; 42. Cross groove; 43. Raised ring; 5. Torsional force groove; 6. Locking rod groove; 61. Circular groove; 62. Guide groove; 63. Slide groove; 64. Locking groove; 7. Lock head; 71. Locking rod; 72. Protrusion; 73. Connecting groove; 8. Rectangular rod; 9. Sleeve; 10. Anti-slip sleeve; 11. Transmission rod; 12. Springback element; 121. Circular cavity; 122. Spring; 13. Control block; 14. Through groove. Detailed Implementation

[0019] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0021] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] like Figures 1-7As shown, this application proposes a biodegradable radiopaque positioning screw for lumbar percutaneous endoscopic surgery, comprising a threaded screw body 1 and a screw head 3 fixedly connected to its end, with a diameter of 0.8-1.0 mm and a length of 4-6 mm. It also includes a marking structure 4 disposed at the end of the screw head 3 for identifying positioning points; the marking structure 4 is a slotted groove 41, a cross groove 42, or a raised ring 43; the slotted groove 41 and the cross groove 42 are formed on the end face of the screw head 3, and the raised ring 43 is machined on the end side wall of the screw head 3. The threaded screw body 1 is of three types: the first type has a diameter of 0.8 mm and a length of 4 mm, with a slotted groove 41 at the end of the screw head 3; the second type has a diameter of 1.0 mm and a length of 6 mm, with a cross groove 42 at the end of the screw head 3; the third type has a diameter of 0.9 mm and a length of 5 mm, with a raised ring 43 on the side wall of the screw head 3. The threaded nail body 1 has a tip 2 at the end furthest from the nail head 3. The threaded nail body 1, tip 2, and nail head 3 are all made of magnesium alloy (WE43), with a chemical composition of Mg-4%Y-3.3%RE(Nd,Gd)-0.5Zr%, where Mg is magnesium, Y is yttrium, RE is rare earth element (mainly composed of neodymium (Nd) and gadolinium (Gd), and Zr represents zirconium. The content of these elements is expressed as a mass percentage. Degradation is achieved within two hours post-surgery through multi-element synergy, while maintaining good X-ray imaging and biocompatibility. The degradation products are magnesium ions, yttrium ions, neodymium ions, and gadolinium ions—essential or safely metabolizable ions for the human body. The threaded nail body 1, tip 2, and nail head 3 all have honeycomb pores with a porosity of 95%-80%, increasing the degradation rate by 5-20 times compared to solid magnesium alloy nails, enabling degradation within two hours post-surgery.

[0025] Specifically, the operating end of the nail head 3 has a torsion groove 5, and a locking rod groove 6 is formed within the torsion groove 5. It also includes a rectangular rod 8. The torsion groove 5 is rectangular, and the rectangular rod 8 fits snugly into the torsion groove 5. A sleeve 9 is fixedly fitted onto the side wall of the rectangular rod 8, and an anti-slip sleeve 10 is fixedly connected to the outer surface of the sleeve 9, improving stability when in contact with the surgeon's hand during operation. A locking head 7, which is locked to the locking rod groove 6, is connected to the end of the rectangular rod 8. A transmission rod 11, which controls the locking head 7, passes through the rectangular rod 8. A spring-loaded element 12 is provided at the end of the transmission rod 11. The rectangular rod 8 is disengaged without touching the threaded nail body 1 due to the cooperation between the locking head 7 and the locking rod groove 6, ensuring the stability of inserting the threaded nail body 1. The locking rod groove 6 includes a circular groove 61 formed at the recessed end of the torsion-bearing groove 5. A pair of guide grooves 62 are formed on the inner wall of the circular groove 61, both extending to the bottom of the circular groove 61. A sliding groove 63 is formed at the bottom end of each of the two guide grooves 62 in a clockwise direction. A pair of locking grooves 64 are formed on the inner wall of the circular groove 61 at the other end of each sliding groove 63. Both sliding grooves 63 are 90-degree arcs, and the depth of the locking groove 64 is half that of the guide groove 62. The locking head 7 includes a connecting groove 73 formed at the bottom end of the rectangular rod 8. A locking rod 71 is movably connected within the connecting groove 73, and protrusions 72 are fixedly connected to both sides of the bottom end of the locking rod 71. When manipulating the threaded nail body 1, first insert the two protrusions 72 into the two guide grooves 62 respectively, then press down on the transmission rod 11 to insert the locking rod 71 into the bottom of the round groove 61, rotate the transmission rod 11 and the locking rod 71 clockwise by 90 degrees, so that the two protrusions 72 slide to the two locking grooves 64 respectively, and finally, under the rebound action of the spring-loaded part 12, the two protrusions 72 slide to the upper end of the two locking grooves 64 respectively, so that the locking rod 71 is positioned at the upper end of the nail head 3.

[0026] More specifically, the rectangular rod 8 has a through groove 14 with a through connecting slot 73. The transmission rod 11 fits into and is movably connected in the through groove 14. The transmission rod 11 is fixedly connected to the locking rod 71, and the outer end of the transmission rod 11 is fixedly connected to a control block 13. The outer wall of the control block 13 has an anti-slip groove. The spring-loaded component 12 includes a circular cavity 121 at the end of the rectangular rod 8. A spring 122 is disposed in the circular cavity 121. The spring 122 is sleeved on the outside of the transmission rod 11. The outer diameter of the spring 122 is smaller than the diameter of the control block 13. One end of the spring 122 always abuts against the control block 13, and the other end of the spring 122 always abuts against the inner wall of the circular cavity 121. When the spring 122 is in the spring-loaded state, the transmission rod 11 is in an upward-springing state, and a certain distance is maintained between the control block 13 and the rectangular rod 8 (when the control block 13 is pressed, the locking rod 71 can be inserted to the deepest part of the circular groove 61). The lock head 7 and rectangular rod 8 described in this application are made of stainless steel 316L or titanium alloy TC4, which have good biocompatibility, strength and corrosion resistance. The lock head 7 and rectangular rod 8 need to be sterilized for recycling and reuse.

[0027] The working principle of this embodiment is as follows: When operating the threaded nail body 1 during surgery, the bottom end of the rectangular rod 8 is inserted into the torsion groove 5. At this time, the two protrusions 72 are vertically aligned with the two guide grooves 62, so that the two protrusions 72 are inserted into the two guide grooves 62 respectively. By pressing the transmission rod 11 downward through the control block 13, the locking rod 71 is inserted into the bottom of the circular groove 61. By holding the control block 13 and rotating the transmission rod 11 and the locking rod 71 clockwise by 90 degrees, the two protrusions 72 slide to the two locking grooves 64 respectively. By releasing the control block 13, the transmission rod 11 and the locking rod 71 rebound under the action of the spring 122, and finally the two protrusions 72 slide to the upper end of the two locking grooves 64 respectively, thereby positioning the locking rod 71 at the upper end of the nail head 3. By holding the sleeve 9 and using the rectangular rod 8, the threaded nail body 1 is screwed into the target bony structures of the lumbar spine, such as the superior articular process, inferior articular process, lamina, and the root of the spinous process. It is important to note that the screwing force is applied to the rectangular rod 8 within the torsion groove 5, and the threaded nail body 1 is firmly fixed by the spiral pattern. Afterwards, the locking head 7 and the rectangular rod 8 are removed, leaving the threaded nail body 1 on the bone for positioning. Using the X-ray imaging characteristics of the positioning nail (straight / cross / ring-shaped) and its microscopic shape, the surgeon can quickly identify the positioning point. The positioning nail remains in place for ≤2 hours throughout the procedure and completely degrades within 2 hours post-surgery. The degradation products are excreted with bodily fluids and do not require removal. The specific operation for removing the locking head 7 and rectangular rod 8 is as follows: Press the control block 13 to make the transmission rod 11 push the locking rod 71 into the bottom of the circular groove 61, and then rotate the control block 13 in the opposite direction by 90 degrees, so that the transmission rod 11 and the locking rod 71 rotate in the opposite direction at the same time. Finally, move the two protrusions 72 into the two guide grooves 62, and then remove the locking head 7 and rectangular rod 8 outward (during the operation, the operator holds the sleeve 9 with one hand to prevent the threaded nail body 1 from loosening in the opposite direction). Removing the locking head 7 and rectangular rod 8 in this way can effectively prevent the threaded nail body 1 from loosening and significantly improve the stability of the threaded nail body 1 after insertion.

[0028] When locating the superior articular process, use the second type of threaded screw body 1. First, connect the locking head 7 to the screw head 3 (the connection method has been described above); insert the endoscope into the surgical channel and locate the bony landmark of the superior articular process under the endoscope; hold the sleeve 9 and align the threaded screw body 1 with the target position, rotate the sleeve 9 clockwise at a speed of about 10 r / min, and screw it in to a depth of 3.5-4 mm; after positioning, remove the locking head 7 and the rectangular rod 8; confirm clear imaging and accurate positioning with anteroposterior and lateral X-ray fluoroscopy. Control the rotation torque at 6-8 N·cm to avoid insufficient torque causing loosening or excessive torque causing bone fracture.

[0029] When locating the inferior articular process, use the first type of threaded screw body 1. Rotate the sleeve 9 clockwise to insert the threaded screw body 1, screwing it in to a depth of 2.5-3mm. After positioning, remove the locking head 7 and rectangular rod 8, and confirm with fluoroscopy. The rotation torque is 4-6 N·cm, avoiding penetration into the spinal canal.

[0030] When locating the lamina, the first type of threaded nail body 1 is used. The sleeve 9 is rotated clockwise to insert the threaded nail body 1, with a screwing depth of 2-2.5mm. After positioning, the locking head 7 and rectangular rod 8 are removed and confirmed by fluoroscopy. The rotation torque is 3-5 N·cm to avoid excessive screwing and damage to the dural sac.

[0031] When locating the root of the spinous process, the third type of threaded nail body 1 is used to locate the root of the spinous process under a microscope; the sleeve 9 is rotated clockwise to insert the threaded nail body 1, and the screwing depth is 3-3.5mm; after positioning, the locking head 7 and the rectangular rod 8 are removed and confirmed by fluoroscopy; the rotation torque is 5-7 N·cm to ensure that the boss is exposed for easy identification under a microscope.

[0032] Case 1: The patient underwent percutaneous endoscopic lumbar discectomy (PELD) for L4-L5 disc herniation, requiring precise localization of the L4 lamina to avoid nerve root damage. Procedure: A single threaded screw (type 1) was selected and, using the locking device (7) and rectangular rod (8), inserted into the posterolateral surgical channel of L4-L5. Under endoscopic guidance, the bony landmarks of the L4 lamina were located. The screw was then screwed into the lamina by rotating the sleeve (9) clockwise. After positioning, the locking device (7) and rectangular rod (8) were removed. Fluoroscopy confirmed accurate positioning. The surgical lens and nucleus pulposus clamp were inserted, and the procedure was performed along the indicated direction of the screw (type 1). During the procedure, if the patient became lost, endoscopic observation of the screw (type 1) was used to quickly regain the field of vision. The surgery lasted 1.5 hours. Two hours post-operation, fluoroscopy confirmed that the positioning screw had degraded without residue, and the patient experienced no neurological complications.

[0033] Case 2: The patient underwent surgery for L5-S1 disc herniation complicated by spinal stenosis, requiring localization of the L5 inferior articular process, S1 superior articular process, and the root of the spinous process. Procedure: One each of the first, second, and third threaded screw bodies (1) were selected and connected to three locking devices (7). Under endoscopic guidance, the three target bony structures were located sequentially, and the positioning screws were implanted according to the corresponding steps described above. After positioning, the locking devices (7) and rectangular rods (8) were removed. Fluoroscopy confirmed that the three positioning screws were clearly visible, and their corresponding positions were distinguished by differences in shape and size. During the operation, the drill direction was adjusted using the threaded screw body (1) as a reference. The operation lasted 1.8 hours. The positioning screws degraded 2 hours postoperatively, and the patient experienced no complications such as spinal canal hemorrhage or nerve irritation.

[0034] The above specific embodiments are merely preferred embodiments of this application. Based on the technical solutions of this application and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments. The above specific embodiments are merely explanations of this application and are not limitations on this application.

Claims

1. A biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy, comprising a threaded screw body (1) and a screw cap (3) fixedly connected to its end, characterized in that, Also includes: The marking structure (4) set at the end of the nail head (3) is used for the identification of the positioning point; A torsion groove (5) is provided at the operating end of the nail head (3), and a locking rod groove (6) is provided in the torsion groove (5). A rectangular rod (8) is provided with a lock head (7) connected to the end of the rectangular rod (8) and locked to the lock rod groove (6). A transmission rod (11) for controlling the lock head (7) is connected through the rectangular rod (8). A spring-loaded part (12) is provided at the end of the transmission rod (11). The rectangular rod (8) is disengaged without touching the threaded nail body (1) through the cooperation between the lock head (7) and the lock rod groove (6).

2. The biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 1, characterized in that, The locking rod groove (6) includes a circular groove (61) formed at the recessed end of the torsion force groove (5). A pair of guide grooves (62) are formed on the inner wall of the circular groove (61), and both guide grooves (62) extend to the bottom of the circular groove (61). The bottom of the two inlet grooves (62) are provided with sliding grooves (63) in a clockwise direction, and the inner wall of the circular groove (61) is provided with a pair of locking grooves (64) located at the other end of the two sliding grooves (63).

3. The biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 2, characterized in that, Both of the slides (63) are 90-degree arcs, and the depth of the locking groove (64) is half that of the guide groove (62).

4. The biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 2, characterized in that, The lock head (7) includes a connecting groove (73) at the bottom of the rectangular rod (8), and a lock rod (71) is movably connected in the connecting groove (73). Both sides of the bottom end of the lock rod (71) are fixedly connected with protrusions (72).

5. A biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 4, characterized in that, The rectangular rod (8) has a through groove (14) with a through connecting groove (73) inside. The transmission rod (11) fits and is movably connected in the through groove (14). The transmission rod (11) is fixedly connected to the locking rod (71), and the outer end of the transmission rod (11) is fixedly connected to the control block (13).

6. A biodegradable contrast-enhancing positioning screw for percutaneous endoscopic lumbar discectomy according to claim 5, characterized in that, The spring-loaded component (12) includes a circular cavity (121) opened at the end of the rectangular rod (8), and a spring (122) is provided in the circular cavity (121). The spring (122) is sleeved on the outside of the transmission rod (11).

7. The biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 1, characterized in that, The side wall of the rectangular rod (8) is fixedly fitted with a sleeve (9), and the outer surface of the sleeve (9) is fixedly connected with an anti-slip sleeve (10).

8. A biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 1, characterized in that, The marking structure (4) is a slot (41), a cross slot (42), or a raised ring (43). The slot (41) and cross slot (42) are formed on the end face of the nail head (3), and the convex ring (43) is machined on the end side wall of the nail head (3).

9. A biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 1, characterized in that, The torsional force groove (5) is a rectangular groove, and the rectangular rod (8) is inserted into the torsional force groove (5).

10. A biodegradable radiopaque positioning screw for percutaneous endoscopic lumbar discectomy according to claim 1, characterized in that, The threaded nail body (1) has a pointed tip (2) at the end away from the nail head (3); The threaded nail body (1), tip (2), and nail head (3) are made of magnesium alloy; The lock head (7) and rectangular rod (8) are made of stainless steel 316L or titanium alloy TC4.

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