Lumbar spondylolisthesis orthosis

Abstract

The present application relates to the technical field of spinal surgical medical instruments, in particular to a lumbar spondylolisthesis orthosis. The orthosis comprises a sleeve for connecting pedicle screws, an axially slidable collet is arranged in the inner cavity of the sleeve, the collet comprises two symmetrically arranged arc-shaped clamping pieces and a disc piece fixedly connected to the upper end of the arc-shaped clamping pieces, a positioning pin is arranged on the inner side wall of the arc-shaped clamping piece, a threaded plug is arranged below the disc piece, the threaded plug is connected to the lower end of a transmission rod, the upper end of the transmission rod passes through the center of the disc piece and is connected to a driving mechanism, spring pieces for pushing the collet to move are arranged on the side wall of the sleeve. The orthosis can accurately correct and position the lumbar vertebrae, improve the standardization and accuracy of the correction and positioning action of the lumbar vertebrae, in addition, a pair of single-shaft pedicle screws arranged at an angle can improve the holding force on the slipped vertebral body, so that it is not easy to slip out during the orthopedic surgery, and the success rate of the surgery is improved.

Description

Technical Field

[0001] This invention relates to the technical field of spinal surgical medical devices, specifically a lumbar spondylolisthesis orthosis. Background Technology

[0002] In a normal person, the lumbar vertebrae are aligned. If, due to congenital or acquired reasons, one lumbar vertebra slips forward relative to an adjacent lumbar vertebra, it is called lumbar spondylolisthesis. After lumbar spondylolisthesis occurs, the patient may have no symptoms and only discover it during an X-ray; or various related symptoms may appear, such as lower back pain, leg pain, numbness, and weakness. In severe cases, bowel and bladder abnormalities may occur. Patients with severe spondylolisthesis may experience lumbar depression, abdominal protrusion, even trunk shortening, and swaying while walking. There are many surgical methods for lumbar spondylolisthesis, such as posterior reduction, pedicle screw fixation, and interbody fusion. Posterior reduction and pedicle screw fixation both use a pedicle screw-rod system for fixation. The current pedicle screw-rod system consists of pedicle screws and connecting rods mounted on the pedicle screws. During use, two pairs of pedicle screws are screwed into two different vertebral bodies, and two connecting rods are longitudinally connected between the two pairs of pedicle screws, serving a connecting and fixing function. Examples include the "Posterior Lumbar Spine Internal Fixation Device" disclosed in Chinese Patent 2010205759082 and the "A Posterior Lumbar Spine Dynamic Fixation Device" disclosed in Chinese Patent 2012200237653. These fixation devices only have a fixation function and no corrective function.

[0003] To achieve perfect reduction or stable fixation of a slipped vertebra, after the pedicle screw is inserted into the vertebra, an external force needs to be applied to lift the slipped vertebra to a certain height, returning it to its normal position before fixing it in place. This screw-lifting action must be done carefully, controlling the amount of force and the range of motion. At this point, the holding force of the pedicle screw plays a decisive role. If bone mass is good, the screw-bone interface friction is greater, the holding force is stronger, and the success rate of internal fixation is higher. Conversely, if osteoporosis is severe, the screw-bone interface holding force is weaker, and the screw is prone to dislodgement under force, leading to internal fixation failure. It is generally believed that the holding force of the pedicle screw in the bone depends on two factors: bone mass (bone density) and screw length and surface friction.

[0004] With the aging population in my country, the number of osteoporosis patients is gradually increasing. A major challenge for osteoporosis patients undergoing spinal screw fixation surgery is that the commonly used uniaxial pedicle screws in current spinal surgery are insufficient to meet the fixation requirements of osteoporotic spinal surgery. During intraoperative repositioning of slipped vertebrae, the screw loosening rate is high, frequently requiring revision surgery, resulting in significant patient suffering and high medical costs. Therefore, increasing the fixation strength of pedicle screws and improving the success rate of surgery has become a thorny issue for spinal surgeons. My other Chinese patent application discloses a "Posterior Lumbar Spine Internal Fixation Corrector" (application number 201811007618.5, publication number CN201811007618.5). This device improves screw holding force by installing a transverse connecting rod between two tilted uniaxial pedicle screws, making them less prone to dislodgement under stress. It is particularly suitable for the surgical treatment of osteoporosis combined with lumbar spine diseases. Furthermore, during surgery, the higher holding force of the screws can be used to reposition misaligned vertebrae, achieving the purpose of correcting deformities. However, to install the transverse connecting rod between the two screws, a specially structured uniaxial pedicle screw must be used. This screw is difficult to manufacture, has poor versatility, and is difficult to promote and apply quickly. Furthermore, although this posterior lumbar fixation device can effectively improve the holding force of the uniaxial pedicle screw on the slipped vertebra, the amount of force and range of motion during vertebral reduction depends entirely on the surgeon's experience and skill. Excessive range of motion or operational errors can easily lead to surgical failure and unnecessary additional damage. Summary of the Invention

[0005] The first objective of this invention is to provide a lumbar spondylolisthesis orthosis that can accurately correct and position the lumbar spine, improving the standardization and accuracy of the correction and positioning actions on the lumbar spine, and avoiding the uncertainties and adverse effects caused by directly lifting the slipped vertebra. The second objective of this invention is to provide a lumbar spondylolisthesis orthosis that can improve the holding force of the uniaxial pedicle screw, making it less likely to dislodge when applying a lifting force to the slipped vertebra through the uniaxial pedicle screw.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows:

[0007] This invention provides a lumbar spondylolisthesis orthosis, comprising a sleeve for connecting pedicle screws, wherein an axially sliding clamp is disposed within the inner cavity of the sleeve, the clamp comprising two symmetrically arranged arc-shaped clamping plates and a disc plate fixedly connected to the upper end of the arc-shaped clamping plates, wherein a positioning pin matching the groove of the pedicle screw tail is disposed on the inner side wall of the arc-shaped clamping plates, and a threaded plug matching the internal thread of the pedicle screw tail is disposed below the disc plate, the threaded plug being a cylindrical structure with external threads, the threaded plug being mounted on the lower end of a transmission rod, and the upper end of the transmission rod being... The threaded plug is connected to the drive mechanism via the center of the disc; the center of the threaded plug has a square hole penetrating the upper and lower end faces, and the lower end of the drive rod is a square rod matching the square hole, so that the threaded plug cannot rotate on the drive rod but can slide up and down within the height range of the square rod; the drive mechanism includes a driven bevel gear fixedly installed on the upper end of the drive rod and a driving bevel gear that is constantly meshed with the driven bevel gear. The driving bevel gear is mounted on the side wall of the sleeve via a wheel axle, and a handwheel is fixedly installed on the outer end of the wheel axle; the side wall of the sleeve is provided with a through hole, and an arc-shaped spring plate... One end is fixedly connected to the outer wall of the sleeve, and the other end passes through the through hole and is fixedly connected to the disc. A horizontal connecting rod is connected to the sleeve, and a telescopic mechanism is provided on the horizontal connecting rod. Clamps are provided at both ends of the horizontal connecting rod, and fastening bolts are installed through the clamps. A convex ring matching the clamps is provided on the outer wall of the sleeve, and the clamps are fitted onto the convex rings. When using the lumbar spondylolisthesis orthosis, at least four pedicle screws are required, two of which are driven into the same normal lumbar vertebral body. These two pedicle screws are driven into the pedicles of the vertebral body. The screws act as support points; two other pedicle screws are driven into the slipped vertebrae to be corrected, serving as force-bearing points; a longitudinal connecting rod is installed between the pedicle screws serving as support points and the pedicle screws serving as force-bearing points, the connecting rod fitting precisely into the tail of the pedicle screw; in use, one end of the longitudinal connecting rod is installed in the tail of the pedicle screw serving as the support point and tightened with a set screw; the other end of the longitudinal connecting rod is installed in the tail of the pedicle screw serving as the force-bearing point, and the two sleeves at both ends of the tie rod are respectively installed in the tails of the two force-bearing pedicle screws.

[0008] This solution allows the sleeve and clamp to be firmly held at the end of the pedicle screw. By pulling the sleeve, the slipped vertebra can be repositioned, which helps to improve the standardization and accuracy of the lumbar spine correction and positioning, and avoids the uncertainties and adverse effects of directly pulling the slipped vertebra.

[0009] Preferably, a cross link is connected to the sleeve, a telescopic mechanism is provided on the cross link, and clamps are provided at both ends of the cross link. Fastening bolts are installed through the clamps, and a convex ring matching the clamps is provided on the outer wall of the sleeve. The clamps are fitted onto the convex rings.

[0010] With this solution, the two sleeves installed at both ends of the cross link correspond to two pedicle screws respectively. These two pedicle screws are driven into the same lumbar joint at a certain angle to each other, which helps to improve the holding force of the screws. The fit between the clamp and the convex ring can make the axis of the pedicle screw and the sleeve form a certain angle, which meets the requirement of the pedicle screw being driven into the lumbar joint at an angle.

[0011] Preferably, the telescopic mechanism includes a sliding sleeve and an adjusting nut coaxially arranged with the sliding sleeve. The adjusting nut is rotatably fitted onto one end of the sliding sleeve through a groove provided at the end of the sliding sleeve. The cross link includes an adjusting rod threaded into the adjusting nut and a fixed rod fixedly connected to the sliding sleeve. The outer ends of the fixed rod and the adjusting rod are each connected to a sleeve.

[0012] This solution allows the telescopic mechanism to adjust the distance between the two sleeves, meeting the needs of different individual surgeries.

[0013] Preferably, the drive mechanism includes a driven bevel gear fixedly mounted on the upper end of the transmission rod and a driving bevel gear that is constantly meshed with the driven bevel gear. The driving bevel gear is mounted on the side wall of the sleeve via a wheel axle, and a handwheel is fixedly mounted on the outer end of the wheel axle.

[0014] This solution uses a bevel gear drive mechanism to change the direction of force transmission, making operation easier. The lifting and lowering of the threaded plug can be precisely controlled by rotating the handwheel, thereby controlling the lifting range of the target lumbar vertebrae.

[0015] Preferably, the drive mechanism includes a worm gear fixedly installed on the upper end of the transmission rod and a worm gear that is constantly meshed with the worm gear. The two ends of the worm gear are rotatably inserted into the side wall of the sleeve, and a handle is fixedly installed on the outer end of the worm gear.

[0016] With this solution, the worm gear drive mechanism has a large gear ratio, which not only enables more precise lifting of the lumbar spine joint, but also has a self-locking function. Once the handle is in place, there will be no rebound unless there is external force.

[0017] Preferably, a locking nut is provided on the adjusting rod.

[0018] This design allows the adjusting nut to be locked in place using a locking nut. Due to this structure, this lumbar spondylolisthesis orthosis can precisely correct and position the lumbar spine, improving the standardization and accuracy of the correction and positioning actions, and avoiding the uncertainties and adverse effects of directly pulling on the slipped vertebra. Furthermore, the orthosis uses a pair of tilted uniaxial pedicle screws to enhance the holding force on the slipped vertebra, making it less likely to dislodge during corrective surgery and increasing the success rate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the chuck's structure.

[0021] Figure 3 This is a three-dimensional structural diagram of the square hole threaded plug and the transmission rod mating.

[0022] Figure 4 This is a three-dimensional structural diagram of the engagement between the threaded plug in the round hole and the transmission rod.

[0023] Figure 5 yes Figure 1 A schematic diagram of the AA cross-sectional structure.

[0024] Figure 6 This is a structural diagram showing the usage state.

[0025] Figure 7 This is a three-dimensional structural diagram of the pedicle screw used in conjunction with the device. Detailed Implementation

[0026] like Figure 1 As shown, the lumbar spondylolisthesis orthosis of the present invention includes a sleeve 2 for connecting the pedicle screw 1. The sleeve 2 is a cylindrical structure made of stainless steel with an open lower end, which can be fitted onto the tail end of the pedicle screw 1.

[0027] like Figure 1 , Figure 2 As shown, the inner cavity of the sleeve 2 is provided with an axially sliding chuck 3. The chuck 3 includes two symmetrically arranged arc-shaped clamping pieces 31 and a disc piece 32 fixedly connected to the upper end of the arc-shaped clamping pieces 31. The arc-shaped clamping pieces 31 are arc-shaped sheet structures that match the inner wall of the sleeve 2. The inner side wall of the arc-shaped clamping pieces 31 is provided with positioning pins 33 that match the grooves of the pedicle screw tail. The positioning pins 33 are cylinders that fit the grooves of the pedicle screw tail. The chuck 3 is an integrated structure made of stainless steel. The arc-shaped clamping pieces 31 are relatively thin and have great elasticity. In the natural state, the two arc-shaped clamping pieces 31 expand outward into a trumpet shape. At this time, the distance between the two positioning pins 33 is large. When the chuck 3 retracts into the inner cavity of the sleeve 2, the two arc-shaped clamping pieces 31 are restricted by the inner wall of the sleeve 2 and are in a contracted state. At this time, the distance between the two positioning pins 33 is small, and they can be locked in the two grooves on the left and right sides of the pedicle screw tail, locking the pedicle screw.

[0028] Additionally, a threaded plug 34 matching the internal thread of the pedicle screw tail is provided below the disc plate 32, such as... Figure 1As shown, the threaded plug 34 is a cylindrical structure with external threads. The threaded plug 34 is installed at the lower end of the transmission rod 5. The upper end of the transmission rod 5 passes through the center of the disc 32 and is connected to the drive mechanism. The drive mechanism is used to drive the transmission rod 5 to rotate. A handle can be directly installed at the top of the transmission rod 5 to drive its rotation; other drive mechanisms can also be used. Figure 3 and Figure 1 As shown on the left, the threaded plug 34 has a square hole in the center that passes through the upper and lower end faces. The lower end of the transmission rod 5 is a square rod that matches the square hole, and the height of the square rod is slightly greater than the height of the square hole, so that the threaded plug 34 cannot rotate on the transmission rod 5 but can slide up and down within the height range of the square rod.

[0029] As another embodiment of the present invention, such as Figure 4 and Figure 1 As shown on the right, the threaded plug 34 also adopts a structure with a central circular hole. In this case, axially distributed sliding keys 51 or convex ribs need to be set on the side wall of the transmission rod 5. At the same time, a keyway or groove matching the sliding key 51 or convex rib is set in the central circular hole of the threaded plug 34 so that the threaded plug 34 can move axially along the sliding key 51.

[0030] In addition, such as Figure 1 As shown, a through hole 21 is provided on the side wall of the sleeve 2. One end of the arc-shaped spring plate 6 is fixedly connected to the outer side wall of the sleeve 2, and the other end passes through the through hole 21 and is fixedly connected to the disc plate 32. The position of the through hole 21 is slightly higher than the upper stop point of the disc plate 32, so that the space below the through hole 21 is sufficient for the chuck 3 to slide up and down. When no external force is applied, the spring plate 6 is in the state of maximum curvature. The lower end of the spring plate 6 lifts the chuck 3 upward, so that the chuck 3 retracts into the inner cavity of the sleeve 2, and the disc plate 32 is located at the upper stop point. During the surgery, when it is necessary to install the sleeve 2 at the tail end of the pedicle screw 1, first hold the sleeve 2 with your hand, and use your index and middle fingers to press the spring plate 6 to extend the spring plate 6. Since the upper end of the spring plate 6 is fixed and cannot move, when the spring plate 6 extends, its lower end enters more of the through hole 21. Push the clamp 3 downward, and the arc-shaped clamp 31 extends out of the sleeve 2 and expands to both sides to form an opening. At this time, the tail end of the pedicle screw 1 can be placed between the two arc-shaped clamps 31, and the positioning pin 33 is aligned with the groove at the tail end of the pedicle screw 1. Then release the fingers that are pressing the spring plate 6, the spring plate 6 returns to its original position, the clamp 3 retracts back into the sleeve 2, the two arc-shaped clamps 31 clamp together, and the positioning pin 33 is inserted into the groove at the tail end of the pedicle screw 1, locking the pedicle screw 1.

[0031] As a further improvement of the present invention, a horizontal connecting rod is connected to the sleeve 2, and a telescopic mechanism is provided on the horizontal connecting rod for adjusting the length of the horizontal connecting rod; clamps 7 are provided at both ends of the horizontal connecting rod, and a convex ring 71 matching the clamp 7 is provided on the outer wall of the sleeve 2. The clamp 7 is fitted onto the convex ring 71, and a fastening bolt 72 is installed through the clamp 7. The fastening bolt 72 is radially distributed along the clamp 7, and the outer end is the tail end of an internal hexagon or external hexagon bolt. The head end of the fastening bolt 72 can be adjusted to press against the convex ring 71 by rotating the fastening bolt 72 with an internal hexagon wrench or other tools. The cross-section of the convex ring 71 is semi-circular. When the clamp 7 is fitted onto the convex ring 71, the sleeve 2 still has a certain range of motion. When the fastening bolt 72 is loosened, the clamp 7 can swing within a certain range and form a certain angle with the convex ring 71. After adjusting the angle, tightening the fastening bolt 72 can lock the clamp 7 and the convex ring 71 at the same position.

[0032] like Figure 1 As shown, the telescopic mechanism includes a sliding sleeve 81 and an adjusting nut 82 coaxially arranged with the sliding sleeve 81. The adjusting nut 82 is rotatably fitted onto one end of the sliding sleeve 81 via a groove provided at the end of the sliding sleeve 81, allowing the adjusting nut 82 to rotate on the sliding sleeve 81 without falling off. Figure 1 In this embodiment, an annular groove is provided on the outer wall of the sliding sleeve 81. In the inner cavity of the adjusting nut 82, one end has a convex ring that matches the groove, and the other end has an internal thread. The convex ring of the adjusting nut 82 is fitted into the groove of the sliding sleeve 81, connecting the two together and allowing them to rotate relative to each other. Of course, as another embodiment of the present invention, a convex ring can also be provided on the outer wall of the sliding sleeve 81, and a groove that matches the convex ring can be provided in the inner cavity of the adjusting nut 82.

[0033] The cross link includes an adjusting rod 83 threaded into an adjusting nut 82 and a fixed rod 84 fixedly connected to a sliding sleeve 81. A sleeve 2 is connected to the outer ends of both the fixed rod 84 and the adjusting rod 83. The sliding sleeve 81 has a central hole for accommodating the adjusting rod 83; this central hole can be a blind hole or a through hole. When the adjusting nut 82 is rotated, the adjusting rod 83 moves axially within the adjusting nut 82, thereby changing the total length of the cross link. When the adjusting rod 83 moves to the left of the adjusting nut 82, its left end passes through the adjusting nut 82 and extends into the central hole of the sliding sleeve 81, effectively reducing the total length of the cross link. Conversely, when the adjusting rod 83 moves to the right of the adjusting nut 82, its left end retracts into the inner cavity of the adjusting nut 82, effectively increasing the total length of the cross link. In addition, to fix the position of the adjusting nut 82, a locking nut 85 can be installed on the adjusting rod 83. After adjusting the position of the adjusting nut 82, tighten the locking nut 85 against the end of the adjusting nut 82 to lock the locking nut 85 and prevent it from easily rotating and changing the length of the cross link.

[0034] Using the above techniques, during surgery, the spacing between the two sleeves 2 can be adjusted according to the actual distance between the two pedicle screws, accurately installing the two sleeves 2 on the tails of the two pedicle screws, and achieving a rigid connection between the two sleeves 2 through a transverse connecting rod.

[0035] like Figure 1 As shown on the left, for ease of surgical operation, the drive mechanism includes a driven bevel gear 91 fixedly mounted on the upper end of the transmission rod 5, and a driving bevel gear 92 that is constantly meshed with the driven bevel gear 91. The driving bevel gear 92 is mounted on the side wall of the sleeve 2 via a wheel axle 93, and a handwheel 94 is fixedly mounted on the outer end of the wheel axle 93. Rotating the handwheel 94 will drive the driven bevel gear 91 to rotate via the driving bevel gear 92, thereby driving the transmission rod 5 to rotate.

[0036] like Figure 1 right side Figure 5 As shown, in another embodiment of the drive mechanism, the drive mechanism includes a worm gear 95 fixedly mounted on the upper end of the transmission rod 5, and a worm 96 that is constantly meshed with the worm gear 95. The two ends of the worm 96 are rotatably inserted into the side wall of the sleeve 2, and a handle 97 is fixedly mounted on the outer end of the worm 96. Rotating the handle 97 will drive the worm gear 95 to rotate through the worm 96, thereby driving the transmission rod 5 to rotate.

[0037] like Figure 6 As shown, at least four pedicle screws are required for use, of which Figure 6 The two pedicle screws at the bottom are inserted into the same normal lumbar vertebral body. These two pedicle screws, inserted from the pedicle of the vertebral body, act as support points; the other two are located at... Figure 6 The pedicle screws above are driven into the slipped vertebral body 15 to be corrected, serving as the stress point.

[0038] These four pedicle screws are all existing, commonly used structures, such as... Figure 7 As shown, the tail end of the nail body 11 with external threads has a U-shaped nail tail 12, the center of the nail tail 12 has an internal thread, and there is a nail tail groove 13 on each of the left and right sides of the nail tail.

[0039] like Figure 6As shown, a longitudinal connecting rod 89 is installed between the pedicle screws serving as support points and the pedicle screws serving as force points. The longitudinal connecting rod 89 is a slender stainless steel or titanium alloy round rod with a diameter slightly smaller than the U-shaped groove of the pedicle screw tail 12, and can be precisely inserted into the pedicle screw tail 12. In use, one end of the longitudinal connecting rod 89 is installed in the pedicle screw tail serving as the support point and tightened with a set screw 88; the other end of the longitudinal connecting rod 89 is installed in the pedicle screw tail serving as the force point, where no set screw is installed. Simultaneously, the length of the transverse tie rod of the lumbar spondylolisthesis orthosis is adjusted according to the distance between the two force points of the pedicle screws. Two sleeves 2 at both ends of the rod are respectively installed at the tails of the pedicle screws at the two stress points. The clamp 3 clamps the tail of the screw and the positioning pin 33 is inserted into the groove of the tail of the screw. Then, the transmission rod 5 is rotated by the drive mechanism, and the threaded plug 34 at the lower end of the transmission rod 5 is screwed into the tail of the pedicle screw. After the threaded plug 34 enters the tail of the screw, it presses against the end of the longitudinal connecting rod 89. The threaded plug 34 presses the longitudinal connecting rod 89 downward. The rigid longitudinal connecting rod 89 will generate an upward reaction force on the pedicle screw at the stress point, and lift the slipped vertebra 15 to be corrected slightly through the pedicle screw until the slipped vertebra 15 is lifted to the normal position. Then the lumbar vertebra can be fixed and the orthosis can be removed.

[0040] Because the lumbar vertebrae to be corrected are lifted and repositioned using threads, the range of motion is small and each movement is highly standardized, which avoids the uncertainties brought about by direct lifting operations and improves the success rate of the surgery.

[0041] Of course, the number of pedicle screws used as support points is not limited to two. Two pedicle screws can be placed on each of the different normal lumbar vertebrae, for a total of four pedicle screws serving as support points. This allows for better support of the longitudinal tie rod and provides a greater lifting reaction force to the pedicle screws at the stress points. It should be noted that both the pedicle screws used as support points and those used as stress points are inserted into the vertebral body in pairs, forming a V-shape at an angle. This allows for greater holding force under stress.

Claims

1. A lumbar spondylolisthesis orthosis, comprising a sleeve (2) for connecting a pedicle screw (1), characterized in that: The sleeve (2) has an axially sliding chuck (3) in its inner cavity. The chuck (3) includes two symmetrically arranged arc-shaped clamping plates (31) and a disc plate (32) fixedly connected to the upper end of the arc-shaped clamping plates (31). The inner wall of the arc-shaped clamping plates (31) is provided with a positioning pin (33) that matches the groove of the pedicle screw tail. The disc plate (32) is provided with a threaded plug (34) that matches the internal thread of the pedicle screw tail. The threaded plug (34) is a cylindrical structure with external threads. The threaded plug (34) is installed at the lower end of the transmission rod (5). The upper end of the transmission rod (5) passes through the center of the disc plate (32) and the drive motor. The transmission mechanism is as follows: the threaded plug (34) has a square hole in the center that passes through the upper and lower end faces, and the lower end of the transmission rod (5) is a square rod that matches the square hole, so that the threaded plug (34) cannot rotate on the transmission rod (5) but can slide up and down within the height range of the square rod; the driving mechanism includes a driven bevel gear (91) fixedly installed on the upper end of the transmission rod (5) and a driving bevel gear (92) that is constantly meshed with the driven bevel gear (91). The driving bevel gear (92) is installed on the side wall of the sleeve (2) through a wheel axle (93), and a handwheel (94) is fixedly installed on the outer end of the wheel axle (93); a through hole (21) is provided on the side wall of the sleeve (2), and an arc-shaped spring One end of the spring (6) is fixedly connected to the outer wall of the sleeve (2), and the other end passes through the through hole (21) and is fixedly connected to the disc (32); a horizontal connecting rod is connected to the sleeve (2), a telescopic mechanism is provided on the horizontal connecting rod, and a clamp (7) is provided at both ends of the horizontal connecting rod. A fastening bolt (72) is installed through the clamp (7). A convex ring (71) matching the clamp (7) is provided on the outer wall of the sleeve (2), and the clamp (7) is fitted onto the convex ring (71); when the lumbar spondylolisthesis orthosis is used, at least four pedicle screws are required, two of which are driven into the same normal lumbar vertebral body, driven from the pedicle of the vertebral body. The two pedicle screws inserted serve as support points; the other two pedicle screws are driven into the slipped vertebra (15) to be corrected, serving as force points; a longitudinal connecting rod (89) is installed between the pedicle screws serving as support points and the pedicle screws serving as force points, and the longitudinal connecting rod (89) can be inserted into the screw tail (12) of the pedicle screw; in use, one end of the longitudinal connecting rod (89) is installed in the screw tail of the pedicle screw serving as support point and is pressed with a set screw (88); the other end of the longitudinal connecting rod (89) is installed in the screw tail of the pedicle screw serving as force point, and the two sleeves (2) at both ends of the horizontal tie rod are respectively installed in the screw tails of the two force point pedicle screws.

2. The lumbar spondylolisthesis orthosis according to claim 1, characterized in that: The telescopic mechanism includes a sliding sleeve (81) and an adjusting nut (82) coaxially arranged with the sliding sleeve (81). The adjusting nut (82) is rotatably fitted onto one end of the sliding sleeve (81) through a groove provided at the end of the sliding sleeve (81). The cross link includes an adjusting rod (83) threadedly installed in the adjusting nut (82) and a fixing rod (84) fixedly connected to the sliding sleeve (81). The outer ends of the fixing rod (84) and the adjusting rod (83) are each connected to a sleeve (2).

3. The lumbar spondylolisthesis orthosis according to claim 2, characterized in that: A locking nut (85) is provided on the adjusting rod (83).

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